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Sample records for proximal tubule hk-2

  1. HK2 Proximal Tubule Epithelial Cells Synthesize and Secrete Plasma Proteins Predominantly Through the Apical Surface.

    Science.gov (United States)

    Zhao, Ke-Wei; Murray, Elsa J Brochmann; Murray, Samuel S

    2017-04-01

    Renal proximal tubule epithelial cells (PTECs) are known to reabsorb salts and small plasma proteins filtered through Bowman's capsule. Following acute kidney injury, PTECs assume some characteristics of hepatocytes in producing various plasma proteins. We now demonstrate that even at a resting state, a PTEC cell line, HK2 expresses mRNAs for and synthesizes and secretes plasma proteins in a complex with complement C3, an α 2 -macroglobulin family chaperone, including albumin, transferrin, α 1 -antitrypsin, α 1 -antichymotrypsin, α 2 -HS-glycoprotein, ceruloplasmin, haptoglobin, C1-inhibitor, secreted phosphoprotein-24, and insulin-like growth factor-1. When grown on transwell inserts, HK2 cells predominantly secrete (∼90%) plasma proteins into the apical side and a smaller fraction into the basolateral side as determined by ELISA assays. When cultured in the presence of exogenous cytokines such as IL1β, IL6, TNFα, BMP2, or TGFβ1, HK2 cell mRNA expressions for plasma proteins were variably affected whereas basolateral secretions were elevated to or in excess of those of the apical level. In addition, HK2 cells produce proTGFβ1 with its intact N-terminal latency associated peptide and latent-TGF-β-binding proteins. The complex cannot be dissociated under conditions of SDS, heating, and electrophoresis. Moreover, HK2 cells maintain their ability to quickly uptake exogenously added serum proteins from the culture medium, as if they are recognized differently by the endocytic receptors. These results provide new insight into the hepatization of PTECs. In addition to their unique uptake of plasma proteins and salts from the filtrate, they are a source of urinary proteins under normal conditions as wells as in chronic and acute kidney diseases. J. Cell. Biochem. 118: 924-933, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Far infrared radiation promotes rabbit renal proximal tubule cell proliferation and functional characteristics, and protects against cisplatin-induced nephrotoxicity.

    Science.gov (United States)

    Chiang, I-Ni; Pu, Yeong-Shiau; Huang, Chao-Yuan; Young, Tai-Horng

    2017-01-01

    Far infrared radiation, a subdivision of the electromagnetic spectrum, is beneficial for long-term tissue healing, anti-inflammatory effects, growth promotion, sleep modulation, acceleration of microcirculation, and pain relief. We investigated if far infrared radiation is beneficial for renal proximal tubule cell cultivation and renal tissue engineering. We observed the effects of far infrared radiation on renal proximal tubules cells, including its effects on cell proliferation, gene and protein expression, and viability. We also examined the protective effects of far infrared radiation against cisplatin, a nephrotoxic agent, using the human proximal tubule cell line HK-2. We found that daily exposure to far infrared radiation for 30 min significantly increased rabbit renal proximal tubule cell proliferation in vitro, as assessed by MTT assay. Far infrared radiation was not only beneficial to renal proximal tubule cell proliferation, it also increased the expression of ATPase Na+/K+ subunit alpha 1 and glucose transporter 1, as determined by western blotting. Using quantitative polymerase chain reaction, we found that far infrared radiation enhanced CDK5R1, GNAS, NPPB, and TEK expression. In the proximal tubule cell line HK-2, far infrared radiation protected against cisplatin-mediated nephrotoxicity by reducing apoptosis. Renal proximal tubule cell cultivation with far infrared radiation exposure resulted in better cell proliferation, significantly higher ATPase Na+/K+ subunit alpha 1 and glucose transporter 1 expression, and significantly enhanced expression of CDK5R1, GNAS, NPPB, and TEK. These results suggest that far infrared radiation improves cell proliferation and differentiation. In HK-2 cells, far infrared radiation mediated protective effects against cisplatin-induced nephrotoxicity by reducing apoptosis, as indicated by flow cytometry and caspase-3 assay.

  3. SGLT2 Inhibitors: Glucotoxicity and Tumorigenesis Downstream the Renal Proximal Tubule?

    Science.gov (United States)

    Bertinat, Romina; Nualart, Francisco; Yáñez, Alejandro J

    2016-08-01

    At present, diabetes mellitus is the main cause of end-stage renal disease. Effective glycaemic management is the most powerful tool to delay the establishment of diabetic complications, such as diabetic kidney disease. Together with reducing blood glucose levels, new anti-diabetic agents are expected not only to control the progression but also to restore known defects of the diabetic kidney. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising anti-diabetic agents that reduce hyperglycaemia by impairing glucose reabsorption in proximal tubule of the kidney and increasing glucosuria. SGLT2 inhibitors have shown to reduce glucotoxicity in isolated proximal tubule cells and also to attenuate expression of markers of overall kidney damage in experimental animal models of diabetes, but the actual renoprotective effect for downstream nephron segments is still unknown and deserves further attention. Here, we briefly discuss possible undesired effects of enhanced glucosuria and albuminuria in nephron segments beyond the proximal tubule after SGLT2 inhibitor treatment, offering new lines of research to further understand the renoprotective action of these anti-diabetic agents. Strategies blocking glucose reabsorption by renal proximal tubule epithelial cells (RPTEC) may be protective for RPTEC, but downstream nephron segments will still be exposed to high glucose and albumin levels through the luminal face. The actual effect of constant enhanced glucosuria over distal nephron segments remains to be established. J. Cell. Physiol. 231: 1635-1637, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  4. Mechanisms of adaptation to chronic respiratory acidosis in the rabbit proximal tubule.

    OpenAIRE

    Krapf, R

    1989-01-01

    The hyperbicarbonatemia of chronic respiratory acidosis is maintained by enhanced bicarbonate reabsorption in the proximal tubule. To investigate the cellular mechanisms involved in this adaptation, cell and luminal pH were measured microfluorometrically using (2",7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein in isolated, microperfused S2 proximal convoluted tubules from control and acidotic rabbits. Chronic respiratory acidosis was induced by exposure to 10% CO2 for 52-56 h. Tubules from ac...

  5. Atgl gene deletion predisposes to proximal tubule damage by impairing the fatty acid metabolism

    International Nuclear Information System (INIS)

    Chen, Wen; Zhang, Qiong; Cheng, Shiwu; Huang, Jie; Diao, Ge; Han, Jian

    2017-01-01

    Fibrosis is the final common pathway of chronic kidney disease (CKD). Normal lipid metabolism is integral to renal physiology, and disturbances of renal lipid metabolism are increasingly being linked with CKD, including the fibrosis. Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme of lipolysis. In the present study, we used Atgl −/− mice to investigate whether ATGL played a role in the regulation of proximal convoluted tubule (PCT) lipid metabolism and renal fibrosis development. ATGL deficiency led to lipid vacuolation of PCT and tubulointerstitial fibrosis, accompanied by massive albuminuria and decreased creatinine clearance rate (Ccr). In vitro experiments indicated that inhibition of ATGL in proximal tubular cell line HK-2 promoted intracellular lipid deposition, reactive oxygen species (ROS) accumulation and cell apoptosis. Both in vitro and in vivo experiments showed that ATGL inhibition decreased the renal peroxisome proliferator-activated receptorα(PPARα) expression, which implied the suppressed lipid metabolism. The antioxidant N-acetylcysteine (NAC) could partially reverse the effect of ROS accumulation and cell apoptosis, but could not restore the PPARαdecrease. These data raise the possibility that ATGL deficiency could impair the renal fatty acid metabolism though inhibiting PPARαexpression, which may lead to lipid deposition and cell apoptosis of PCT, and finally contribute to the renal fibrosis and dysfunction. - Highlights: • Atgl −/− mice develop tubulointerstitial damage and renal dysfunction. • ATGL deficiency results in lipid accumulation and apoptosis of proximal tubular cells. • ROS scavenger alleviates the ATGL-knockdown mediated lipid accumulation and apoptosis. • PPARαdown-regulation is the reason of ROS elevating in ATGL-knockdown HK-2 cells.

  6. Digital three-dimensional reconstruction and ultrastructure of the mouse proximal tubule

    DEFF Research Database (Denmark)

    Zhai, X.Y.; Birn, H.; Jensen, K.B.

    2003-01-01

    . In the medullary rays, these are arranged in layers outside the clusters of more superficial tubules. In contrast to rat and human kidney, no major segmental variation in the ultrastructure of the proximal tubule was identified, and no parameters enabled definition of distinct segments in this strain of mice......, detailed analyses of normal mouse kidney structure and organization are lacking. This study describes the 3D organization and ultrastructural, segmental variation of the mouse kidney proximal tubule. A total of 160 proximal tubules in three C57/BL/6J mouse kidneys were analyzed on 800 serial sections from...

  7. Bioprinting of 3D Convoluted Renal Proximal Tubules on Perfusable Chips

    Science.gov (United States)

    Homan, Kimberly A.; Kolesky, David B.; Skylar-Scott, Mark A.; Herrmann, Jessica; Obuobi, Humphrey; Moisan, Annie; Lewis, Jennifer A.

    2016-10-01

    Three-dimensional models of kidney tissue that recapitulate human responses are needed for drug screening, disease modeling, and, ultimately, kidney organ engineering. Here, we report a bioprinting method for creating 3D human renal proximal tubules in vitro that are fully embedded within an extracellular matrix and housed in perfusable tissue chips, allowing them to be maintained for greater than two months. Their convoluted tubular architecture is circumscribed by proximal tubule epithelial cells and actively perfused through the open lumen. These engineered 3D proximal tubules on chip exhibit significantly enhanced epithelial morphology and functional properties relative to the same cells grown on 2D controls with or without perfusion. Upon introducing the nephrotoxin, Cyclosporine A, the epithelial barrier is disrupted in a dose-dependent manner. Our bioprinting method provides a new route for programmably fabricating advanced human kidney tissue models on demand.

  8. Active ion transport in the renal proximal tubule. II. Ionic dependence of the Na pump

    OpenAIRE

    1984-01-01

    The dependence of Na pump activity on intracellular and extracellular Na+ and K+ was investigated using a suspension of rabbit cortical tubules that contained mostly (86%) proximal tubules. The ouabain- sensitive rate of respiration (QO2) was used to measure the Na pump activity of intact tubules, and the Na,K-ATPase hydrolytic activity was measured using lysed proximal tubule membranes. The dependence (K0.5) of the Na pump on intracellular Na+ was affected by the relative intracellular conce...

  9. Cyclophilin B expression in renal proximal tubules of hypertensive rats.

    Science.gov (United States)

    Kainer, D B; Doris, P A

    2000-04-01

    Rat cyclophilin-like protein (Cy-LP) is a candidate hypertension gene initially identified by differential hybridization and implicated in renal mechanisms of salt retention and high blood pressure. We report the molecular characterization of rat cyclophilin B (CypB) and demonstrate, through sequence analysis and an allele-specific polymerase chain reaction primer assay, that CypB but not Cy-LP is expressed in rat kidney. CypB is an endoplasmic reticulum-localized prolyl-isomerase that interacts with elongation initiation factor 2-beta, an important regulator of protein translation and a central component of the endoplasmic reticulum stress response to hypoxia or ATP depletion. Active renal transport of sodium is increased in the spontaneously hypertensive rat (SHR), and there is evidence that this coincides with hypoxia and ATP depletion in the renal cortex. In the present studies we have examined expression of CypB in rat proximal tubules, which contributes to the increased renal sodium reabsorption in this model of hypertension. We report that CypB transcript abundance is significantly elevated in proximal convoluted tubules from SHR compared with the control Wistar-Kyoto strain. This upregulation occurs in weanling animals and precedes the development of hypertension, indicating that it is not a simple response to hypertension in SHR. Further, CypB expression is also higher in a proximal tubule cell line derived from SHR compared with a similar line derived from Wistar-Kyoto rats, indicating that this difference is genetically determined. No sequence differences were observed in the CypB cDNA from these 2 strains. These observations suggest that a genetically determined alteration in proximal tubules from SHR occurs that leads to increased expression of CypB. In view of evidence linking CypB to the regulation of elongation initiation factor-2, the upregulation of CypB may result from metabolic stress.

  10. Luminal uptake and intracellular transport of insulin in renal proximal tubules

    International Nuclear Information System (INIS)

    Hellfritzsch, M.; Christensen, E.I.; Sonne, O.

    1986-01-01

    It is generally accepted that proteins taken up from the renal tubular fluid are transported into lysosomes in proximal tubule cells. Recently, however, it has been postulated that insulin in isolated perfused rat kidneys did not accumulate in lysosomes but to a certain degree in the Golgi region. The present study was undertaken to investigate the intracellular handling of biologically unaltered insulin in rat renal proximal tubule cells. Rats were prepared for in vivo micropuncture and either a colloidal gold insulin complex or insulin monoiodinated in the A-14 position ( 125 I-insulin) was microinfused into proximal tubules. After 5, 10, 25 or 60 min the tubules were fixed by microinfusion of glutaraldehyde and processed for electron microscopy or electron microscope autoradiography. A qualitative analysis of tubules infused with colloidal gold insulin or 125 I-insulin showed that insulin was taken up by endocytosis and transported to lysosomes, and a quantitative autoradiographic analysis of the 125 I-insulin microinfused tubules showed that the grain density after five min was significantly increased for endocytic vacuoles and for lysosomes. After 60 min the grain density was still significant over lysosomes. The accumulation of grains was non-significant over all other areas analyzed at any time. This study shows that insulin is taken up from the luminal side of the proximal tubule by endocytosis and transported to the lysosomes. There was no significant transport to the Golgi region

  11. Regulation of proximal tubule vacuolar H+-ATPase by PKA and AMP-activated protein kinase

    Science.gov (United States)

    Al-bataineh, Mohammad M.; Gong, Fan; Marciszyn, Allison L.; Myerburg, Michael M.

    2014-01-01

    The vacuolar H+-ATPase (V-ATPase) mediates ATP-driven H+ transport across membranes. This pump is present at the apical membrane of kidney proximal tubule cells and intercalated cells. Defects in the V-ATPase and in proximal tubule function can cause renal tubular acidosis. We examined the role of protein kinase A (PKA) and AMP-activated protein kinase (AMPK) in the regulation of the V-ATPase in the proximal tubule as these two kinases coregulate the V-ATPase in the collecting duct. As the proximal tubule V-ATPases have different subunit compositions from other nephron segments, we postulated that V-ATPase regulation in the proximal tubule could differ from other kidney tubule segments. Immunofluorescence labeling of rat ex vivo kidney slices revealed that the V-ATPase was present in the proximal tubule both at the apical pole, colocalizing with the brush-border marker wheat germ agglutinin, and in the cytosol when slices were incubated in buffer alone. When slices were incubated with a cAMP analog and a phosphodiesterase inhibitor, the V-ATPase accumulated at the apical pole of S3 segment cells. These PKA activators also increased V-ATPase apical membrane expression as well as the rate of V-ATPase-dependent extracellular acidification in S3 cell monolayers relative to untreated cells. However, the AMPK activator AICAR decreased PKA-induced V-ATPase apical accumulation in proximal tubules of kidney slices and decreased V-ATPase activity in S3 cell monolayers. Our results suggest that in proximal tubule the V-ATPase subcellular localization and activity are acutely coregulated via PKA downstream of hormonal signals and via AMPK downstream of metabolic stress. PMID:24553431

  12. Visfatin Reduces Gap Junction Mediated Cell-to-Cell Communication in Proximal Tubule-Derived Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Claire E. Hills

    2013-11-01

    Full Text Available Background/Aims: In the current study we examined if the adipocytokine, visfatin, alters connexin-mediated intercellular communication in proximal tubule-derived epithelial cells. Methods: The effects of visfatin (10-200ng/mL on cell viability and cytotoxicity in HK2-cells were assessed by MTT, crystal violet and lactate dehydrogenase assays. Western blot analysis was used to confirm expression of Cx26, Cx40 and Cx43. The effect of visfatin (10-200ng/mL on TGF-β1 secretion was confirmed by ELISA, and the effects of both TGF-β1 (2-10ng/mL and visfatin (10-200ng/mL on connexin expression were assessed by western blot. Functional intercellular communication was determined using transfer of Lucifer Yellow and paired-whole cell patch clamp electrophysiology. Results: In low glucose (5mM, visfatin (10-200ng/mL did not affect membrane integrity, cytotoxicity or cell viability at 48hrs, but did evoke a concentration-dependent reduction in Cx26 and Cx43 expression. The expression of Cx40 was unaffected. At 48hrs, visfatin (10-200ng/mL increased the secretion of TGF-β1 and the visfatin-evoked changes in connexin expression were mimicked by exogenous application of the pro-fibrotic cytokine (2-10ng/ml. Visfatin reduced dye transfer between coupled cells and decreased functional conductance, with levels falling by 63% as compared to control. Although input resistance was increased following visfatin treatment by 166%, the change was not significant as compared to control. The effects of visfatin on Cx-expression and cell-coupling were blocked in the presence of a TGF-β1 specific neutralizing antibody. Conclusions: The adipocytokine visfatin selectively evoked a non-toxic reduction in connexin expression in HK2-cells. The loss in gap-junction associated proteins was mirrored by a loss in functional conductance between coupled cells. Visfatin increased TGF-β secretion and the pattern of change for connexins expression was mimicked by exogenous

  13. Reduced Insulin Receptor Expression Enhances Proximal Tubule Gluconeogenesis.

    Science.gov (United States)

    Pandey, Gaurav; Shankar, Kripa; Makhija, Ekta; Gaikwad, Anil; Ecelbarger, Carolyn; Mandhani, Anil; Srivastava, Aneesh; Tiwari, Swasti

    2017-02-01

    Reduced insulin receptor protein levels have been reported in the kidney cortex from diabetic humans and animals. We recently reported that, targeted deletion of insulin receptor (IR) from proximal tubules (PT) resulted in hyperglycemia in non-obese mice. To elucidate the mechanism, we examined human proximal tubule cells (hPTC) and C57BL/6 mice fed with high-fat diet (HFD, 60% fat for 20 weeks). Immunoblotting revealed a significantly lower protein level of IR in HFD compare to normal chow diet (NCD). Furthermore, a blunted rise in p-AKT 308 levels in the kidney cortex of HFD mice was observed in response to acute insulin (0.75 IU/kg body weight, i.p) relative to NCD n = 8/group, P gluconeogenesis. Transcript levels of the gluconeogenic enzyme PEPCK were significantly increased in cAMP/DEXA-stimulated hPTC cells (n = 3, P gluconeogenesis and PEPCK induction was significantly attenuated in IR (siRNA) silenced hPTC (n = 3, P gluconeogenesis. Thus reduced insulin signaling of the proximal tubule may contribute to hyperglycemia in the metabolic syndrome via elevated gluconeogenesis. J. Cell. Biochem. 118: 276-285, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Innervation of the renal proximal convoluted tubule of the rat

    International Nuclear Information System (INIS)

    Barajas, L.; Powers, K.

    1989-01-01

    Experimental data suggest the proximal tubule as a major site of neurogenic influence on tubular function. The functional and anatomical axial heterogeneity of the proximal tubule prompted this study of the distribution of innervation sites along the early, mid, and late proximal convoluted tubule (PCT) of the rat. Serial section autoradiograms, with tritiated norepinephrine serving as a marker for monoaminergic nerves, were used in this study. Freehand clay models and graphic reconstructions of proximal tubules permitted a rough estimation of the location of the innervation sites along the PCT. In the subcapsular nephrons, the early PCT (first third) was devoid of innervation sites with most of the innervation occurring in the mid (middle third) and in the late (last third) PCT. Innervation sites were found in the early PCT in nephrons located deeper in the cortex. In juxtamedullary nephrons, innervation sites could be observed on the PCT as it left the glomerulus. This gradient of PCT innervation can be explained by the different tubulovascular relationships of nephrons at different levels of the cortex. The absence of innervation sites in the early PCT of subcapsular nephrons suggests that any influence of the renal nerves on the early PCT might be due to an effect of neurotransmitter released from renal nerves reaching the early PCT via the interstitium and/or capillaries

  15. Passive permeability of salicylic acid in renal proximal S2 and S3 tubules

    International Nuclear Information System (INIS)

    Chatton, J.Y.; Roch-Ramel, F.

    1991-01-01

    The role of nonionic diffusion in the transport of salicylic acid across rabbit proximal S2 and S3 segments was investigated using the in vitro isolated perfused tubule technique. The [ 14 C] salicylic acid apparent reabsorptive permeability (P'I-b, 10(-5) cm/s) was measured at 19 degrees C with luminal solutions kept at different pH and bath maintained at pH 7.4. In S2 tubules, P'I-b was 25.0 +/- 3.5 when luminal pH was 6.0; P'I-b decreased to 8.1 +/- 1.4 and to 4.4 +/- 1.2 at a luminal pH of 6.5 and 7.0, respectively. In S3 tubules, P'I-b was 17.6 +/- 2.4, 5.3 +/- 1.1 and 3.4 +/- 1.1 at a luminal pH of 6.0, 6.5 and 7.0, respectively. There was a close correlation between P'I-b and the calculated proportion of nonionized salicylic acid present at each pH, indicating that only the nonionized molecule could diffuse in our conditions. We calculated the apparent permeability of nonionic salicylic acid and found 0.248 +/- 0.032 cm/s for S2 and 0.176 +/- 0.022 cm/s for S3 tubules. These calculated permeabilities were independent of pH

  16. Cellular localization of uranium in the renal proximal tubules during acute renal uranium toxicity.

    Science.gov (United States)

    Homma-Takeda, Shino; Kitahara, Keisuke; Suzuki, Kyoko; Blyth, Benjamin J; Suya, Noriyoshi; Konishi, Teruaki; Terada, Yasuko; Shimada, Yoshiya

    2015-12-01

    Renal toxicity is a hallmark of uranium exposure, with uranium accumulating specifically in the S3 segment of the proximal tubules causing tubular damage. As the distribution, concentration and dynamics of accumulated uranium at the cellular level is not well understood, here, we report on high-resolution quantitative in situ measurements by high-energy synchrotron radiation X-ray fluorescence analysis in renal sections from a rat model of uranium-induced acute renal toxicity. One day after subcutaneous administration of uranium acetate to male Wistar rats at a dose of 0.5 mg uranium kg(-1) body weight, uranium concentration in the S3 segment of the proximal tubules was 64.9 ± 18.2 µg g(-1) , sevenfold higher than the mean renal uranium concentration (9.7 ± 2.4 µg g(-1) ). Uranium distributed into the epithelium of the S3 segment of the proximal tubules and highly concentrated uranium (50-fold above mean renal concentration) in micro-regions was found near the nuclei. These uranium levels were maintained up to 8 days post-administration, despite more rapid reductions in mean renal concentration. Two weeks after uranium administration, damaged areas were filled with regenerating tubules and morphological signs of tissue recovery, but areas of high uranium concentration (100-fold above mean renal concentration) were still found in the epithelium of regenerating tubules. These data indicate that site-specific accumulation of uranium in micro-regions of the S3 segment of the proximal tubules and retention of uranium in concentrated areas during recovery are characteristics of uranium behavior in the kidney. Copyright © 2015 John Wiley & Sons, Ltd.

  17. 'Special K' and a Loss of Cell-To-Cell Adhesion in Proximal Tubule-Derived Epithelial Cells: Modulation of the Adherens Junction Complex by Ketamine

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    Hills, Claire E.; Jin, Tianrong; Siamantouras, Eleftherios; Liu, Issac K-K; Jefferson, Kieran P.; Squires, Paul E.

    2013-01-01

    Ketamine, a mild hallucinogenic class C drug, is the fastest growing ‘party drug’ used by 16–24 year olds in the UK. As the recreational use of Ketamine increases we are beginning to see the signs of major renal and bladder complications. To date however, we know nothing of a role for Ketamine in modulating both structure and function of the human renal proximal tubule. In the current study we have used an established model cell line for human epithelial cells of the proximal tubule (HK2) to demonstrate that Ketamine evokes early changes in expression of proteins central to the adherens junction complex. Furthermore we use AFM single-cell force spectroscopy to assess if these changes functionally uncouple cells of the proximal tubule ahead of any overt loss in epithelial cell function. Our data suggests that Ketamine (24–48 hrs) produces gross changes in cell morphology and cytoskeletal architecture towards a fibrotic phenotype. These physical changes matched the concentration-dependent (0.1–1 mg/mL) cytotoxic effect of Ketamine and reflect a loss in expression of the key adherens junction proteins epithelial (E)- and neural (N)-cadherin and β-catenin. Down-regulation of protein expression does not involve the pro-fibrotic cytokine TGFβ, nor is it regulated by the usual increase in expression of Slug or Snail, the transcriptional regulators for E-cadherin. However, the loss in E-cadherin can be partially rescued pharmacologically by blocking p38 MAPK using SB203580. These data provide compelling evidence that Ketamine alters epithelial cell-to-cell adhesion and cell-coupling in the proximal kidney via a non-classical pro-fibrotic mechanism and the data provides the first indication that this illicit substance can have major implications on renal function. Understanding Ketamine-induced renal pathology may identify targets for future therapeutic intervention. PMID:24009666

  18. Acid-base transport by the renal proximal tubule.

    Science.gov (United States)

    Skelton, Lara A; Boron, Walter F; Zhou, Yuehan

    2010-01-01

    Each day, the kidneys filter 180 L of blood plasma, equating to some 4,300 mmol of the major blood buffer, bicarbonate (HCO3-). The glomerular filtrate enters the lumen of the proximal tubule (PT), and the majority of filtered HCO3- is reclaimed along the early (S1) and convoluted (S2) portions of the PT in a manner coupled to the secretion of H+ into the lumen. The PT also uses the secreted H+ to titrate non-HCO3- buffers in the lumen, in the process creating "new HCO3-" for transport into the blood. Thus, the PT - along with more distal renal segments - is largely responsible for regulating plasma [HCO3-]. In this review we first focus on the milestone discoveries over the past 50+ years that define the mechanism and regulation of acid-base transport by the proximal tubule. Further on in the review, we will summarize research still in progress from our laboratory, work that addresses the problem of how the PT is able to finely adapt to acid-base disturbances by rapidly sensing changes in basolateral levels of HCO3- and CO2 (but not pH), and thereby to exert tight control over the acid-base composition of the blood plasma.

  19. Functionally induced changes in water transport in the proximal tubule segment of rat kidneys

    DEFF Research Database (Denmark)

    Faarup, Poul; von Holstein-Rathlou, Niels-Henrik; Nørgaard, Tove

    2011-01-01

    To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the pr......To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure...... segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries....

  20. Diglycolic acid inhibits succinate dehydrogenase activity in human proximal tubule cells leading to mitochondrial dysfunction and cell death.

    Science.gov (United States)

    Landry, Greg M; Dunning, Cody L; Conrad, Taylor; Hitt, Mallory J; McMartin, Kenneth E

    2013-08-29

    Diethylene glycol (DEG) is a solvent used in consumer products allowing the increased risk for consumer exposure. DEG metabolism produces two primary metabolites, 2-hydroxyethoxyacetic acid (2-HEAA) and diglycolic acid (DGA). DGA has been shown to be the toxic metabolite responsible for the proximal tubule cell necrosis seen in DEG poisoning. The mechanism of DGA toxicity in the proximal tubule cell is not yet known. The chemical structure of DGA is very similar to citric acid cycle intermediates. Studies were designed to assess whether its mechanism of toxicity involves disruption of cellular metabolic pathways resulting in mitochondrial dysfunction. First, DGA preferentially inhibited succinate dehydrogenase, including human kidney cell enzyme, but had no effect on other citric acid cycle enzyme activities. DGA produces a cellular ATP depletion that precedes cell death. Human proximal tubule (HPT) cells, pre-treated with increasing DGA concentrations, showed significantly decreased oxygen consumption. DGA did not increase lactate levels, indicating no effect on glycolytic activity. DGA increased reactive oxygen species (ROS) production in HPT cells in a concentration and time dependent manner. These results indicate that DGA produced proximal tubule cell dysfunction by specific inhibition of succinate dehydrogenase and oxygen consumption. Disruption of these processes results in decreased energy production and proximal tubule cell death. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Proteomic approaches in understanding a detected relationship between chemotherapy-induced nephrotoxicity and cell respiration in HK-2 cells.

    Science.gov (United States)

    Perez, Juliana Dinéia; Colucci, Juliana Almada; Sakata, Maísa Mayumi; Cunha, Tatiana Sousa; Arita, Danielle Yuri; Casarini, Dulce Elena

    2011-01-01

    Nephrotoxicity is a prominent component of the profile of chemotherapeutic agents and to date proteomics has represented the main technique to identify protein profiles in response to xenobiotic exposure. We made use of two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight analysis to evaluate chemotoxicity effects of cisplatin (CPT) and carboplatin (CB) on proteins from human renal proximal tubule epithelial cells (HK-2). Tandem mass spectrometry analysis showed that ATP synthase subunit α and serine hydroxymethyltransferase were only expressed in HK-2 cells exposed to CPT. Since CPT causes damage in cellular respiration, we suggest that this might be a protective adaptation to CPT-induced nephrotoxicity. Thioredoxin-dependent peroxide reductase disappeared in the CPT group and was upregulated in the CB group, suggesting that CB exposure stimulates preventive apoptotic mechanisms. We suggest a relationship between chemotherapeutic agent-induced nephrotoxicity and cell respiration. The identification of proteins differentially expressed in HK-2 cells, when exposed to CPT and CB, not only supplies important information to understand the molecular action mechanisms, which are triggered by metal-based drugs in cell nephrotoxicity, but also can lead to the design of more effective anticancer drugs. These results provide important insights into the investigation of possible biomarker(s) of toxicity that could eventually reduce the side effects of chemotherapeutic agents. Copyright © 2011 S. Karger AG, Basel.

  2. Dual Regulation of Gluconeogenesis by Insulin and Glucose in the Proximal Tubules of the Kidney.

    Science.gov (United States)

    Sasaki, Motohiro; Sasako, Takayoshi; Kubota, Naoto; Sakurai, Yoshitaka; Takamoto, Iseki; Kubota, Tetsuya; Inagi, Reiko; Seki, George; Goto, Moritaka; Ueki, Kohjiro; Nangaku, Masaomi; Jomori, Takahito; Kadowaki, Takashi

    2017-09-01

    Growing attention has been focused on the roles of the proximal tubules (PTs) of the kidney in glucose metabolism, including the mechanism of regulation of gluconeogenesis. In this study, we found that PT-specific insulin receptor substrate 1/2 double-knockout mice, established by using the newly generated sodium-glucose cotransporter 2 (SGLT2)-Cre transgenic mice, exhibited impaired insulin signaling and upregulated gluconeogenic gene expression and renal gluconeogenesis, resulting in systemic insulin resistance. In contrast, in streptozotocin-treated mice, although insulin action was impaired in the PTs, the gluconeogenic gene expression was unexpectedly downregulated in the renal cortex, which was restored by administration of an SGLT1/2 inhibitor. In the HK-2 cells, the gluconeogenic gene expression was suppressed by insulin, accompanied by phosphorylation and inactivation of forkhead box transcription factor 1 (FoxO1). In contrast, glucose deacetylated peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), a coactivator of FoxO1, via sirtuin 1, suppressing the gluconeogenic gene expression, which was reversed by inhibition of glucose reabsorption. These data suggest that both insulin signaling and glucose reabsorption suppress the gluconeogenic gene expression by inactivation of FoxO1 and PGC1α, respectively, providing insight into novel mechanisms underlying the regulation of gluconeogenesis in the PTs. © 2017 by the American Diabetes Association.

  3. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman's capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium.

    Science.gov (United States)

    Tabatabai, Niloofar M; North, Paula E; Regner, Kevin R; Kumar, Suresh N; Duris, Christine B; Blodgett, Amy B

    2014-08-01

    In kidney nephron, parietal epithelial cells line the Bowman's capsule and function as a permeability barrier for the glomerular filtrate. Bowman's capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman's capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane (BBM) of epithelial cells in the early segment of the proximal tubule. We hypothesized that SGLT2 is expressed in tubularized Bowman's capsule and used our novel antibody to test this hypothesis. Immunohistochemical analysis was performed with our SGLT2 antibody on C57BL/6 mouse kidney prone to have tubularized Bowman's capsules. Cell membrane was examined with periodic acid-Schiff (PAS) stain. The results showed that SGLT2 was localized on BBM of the proximal tubules in young and adult mice. Bowman's capsules were lined mostly with normal brush border-less parietal epithelial cells in young mice, while they were almost completely covered with proximal tubule-like cells in adult mice. Regardless of age, SGLT2 was expressed on BBM of the tubularized Bowman's capsule but did not co-localize with nephrin in the glomerulus. SGLT2-expressing tubular cells expanded from the urinary pole toward the vascular pole of the Bowman's capsule. This study identified the localization of SGLT2 in the Bowman's capsule. Bowman's capsules with tubular metaplasia may acquire roles in reabsorption of filtered glucose and sodium.

  4. The role of Omi/HtrA2 protease in neonatal postasphyxial serum-induced apoptosis in human kidney proximal tubule cells

    Directory of Open Access Journals (Sweden)

    Zhang Yong

    2012-01-01

    Full Text Available Omi/HtrA2, a proapoptotic mitochondrial serine protease, is involved in both caspase-dependent and caspaseindependent apoptosis. A growing body of evidence indicates that Omi/HtrA2 plays an important role in the pathogenesis of a variety of ischemia-reperfusion (I/R injuries. However, the role of Omi/HtrA2 in renal injuries that occur in neonates with asphyxia remains unknown. The present study was designed to investigate whether Omi/HtrA2 plays an important role in the types of renal injuries that are induced by neonatal postasphyxial serum. Human renal proximal tubular cell line (HK-2 cells were used as targets. A 20% serum taken from neonates one day after asphyxia was applied to target cells as an attacking factor. We initially included control and postasphyxial serum-attacked groups and later included a ucf-101 group in the study. In the postasphyxial serum-treated group, cytosolic Omi/HtrA2 and caspase-3 expression in HK-2 cells was significantly higher than in the control group. Moreover, the concentration of cytosolic caspase-3 was found to be markedly decreased in HK-2 cells in the ucf-101 group. Our results suggest both that postasphyxial serum has a potent apoptosis-inducing effect on HK-2 cells and that this effect can be partially blocked by ucf-101. Taken together, our results demonstrate for the first time that postasphyxial serum from neonates results in Omi/HtrA2 translocation from the mitochondria to the cytosol, where it promotes HK-2 cell apoptosis via a protease activity-dependent, caspase-mediated pathway.

  5. Cystine uptake by cultured cells originating from dog proximal tubule segments

    International Nuclear Information System (INIS)

    States, B.; Reynolds, R.; Lee, J.; Segal, S.

    1990-01-01

    Large numbers of kidney epithelial cells were cultured successfully from isolated dog proximal tubule segments. Cells in primary culture and in first passage retained the cystine-dibasic amino acid co-transporter system which is found in vivo and in freshly isolated proximal tubule segments. In contrast to other cultured cells, the cystine-glutamate anti-porter was absent in primary cultures. However, this anti-porter system seemed to be developing in cells in first passage. The intracellular ratio of cysteine:reduced glutathione (CSH:GSH) was maintained at 1:36 in both primary cultures and in low passage cells. Incubation of cells in primary culture for 5 min at 37 degrees C with 0.025 mM [ 35 S]L-cystine resulted in incorporation of approximately 36 and 8.5% of the label into intracellular CSH and GSH, respectively. These cultured cells, therefore, seem to be an excellent model system for the eventual elucidation of (a) the inticacies of cystine metabolism and (b) regulation of (1) the cystine-dibasic amino acid co-transporter system and (2) the development of the cysteine-glutamate anti-porter system

  6. Novel Hg2+-Induced Nephropathy in Rats and Mice Lacking Mrp2: Evidence of Axial Heterogeneity in the Handling of Hg2+ Along the Proximal Tubule

    Science.gov (United States)

    Zalups, Rudolfs K.; Joshee, Lucy; Bridges, Christy C.

    2014-01-01

    The role of the multi-resistance protein 2 (Mrp2) in the nephropathy induced by inorganic mercuric mercury (Hg2+) was studied in rats (TR−) and mice (Mrp2−/−), which lack functional Mrp2, and control animals. Animals were exposed to nephrotoxic doses of HgCl2. Forty-eight or 24 hours after exposure, tissues were harvested and analyzed for Hg content and markers of injury. Histological analyses revealed that the proximal tubular segments affected pathologically by Hg2+ were significantly different between Mrp2-deficient animals and controls. In the absence of Mrp2, cellular injury localized almost exclusively in proximal tubular segments in the subcapsular (S1) to midcortical regions (early S2) of the kidney. In control animals, cellular death occurred mainly in the proximal tubular segments in the inner cortex (late S2) and outer stripe of the outer medulla (S3). These differences in renal pathology indicate that axial heterogeneity exists along the proximal tubule with respect to how mercuric ions are handled. Total renal and hepatic accumulation of mercury was also greater in animals lacking Mrp2 than in controls, indicating that Mrp2 normally plays a significant role in eliminating mercuric ions from within proximal tubular cells and hepatocytes. Analyses of plasma creatinine, BUN, and renal expression of Kim-1 and Ngal tend to support the severity of the nephropathies detected histologically. Collectively, our findings indicate that a fraction of mercuric ions is normally secreted by Mrp2 in early portions of proximal tubules into the lumen and then is absorbed downstream in straight portions, where mercuric species typically induce toxic effects. PMID:25145654

  7. Fluid transport and ion fluxes in mammalian kidney proximal tubule: a model analysis of isotonic transport

    DEFF Research Database (Denmark)

    Larsen, E.H.; Møbjerg, N.; Sørensen, Jens Nørkær

    2006-01-01

    transport similar to rat proximal tubule. Na+ recirculation is required for truly isotonic transport. The tonicity of the absorbate and the recirculation flux depend critically on ion permeabilities of interspace basement membrane. Conclusion: Our model based on solute-solvent coupling in lateral space......Aim: By mathematical modelling, we analyse conditions for near-isotonic and isotonic transport by mammalian kidney proximal tubule. Methods: The model comprises compliant lateral intercellular space (lis) and cells, and infinitely large luminal and peritubular compartments with diffusible species......: Na+, K+, Cl and an intracellular non-diffusible anion. Unknown model variables are solute concentrations, electrical potentials, volumes and hydrostatic pressures in cell and lis, and transepithelial potential. We used data mainly from rat proximal tubule to model epithelial cells and interspace...

  8. The Leptospira outer membrane protein LipL32 induces tubulointerstitial nephritis-mediated gene expression in mouse proximal tubule cells.

    Science.gov (United States)

    Yang, Chih-Wei; Wu, Mai-Szu; Pan, Ming-Jeng; Hsieh, Wang-Ju; Vandewalle, Alain; Huang, Chiu-Ching

    2002-08-01

    Tubulointerstitial nephritis is a main renal manifestation caused by pathogenic leptospira that accumulate mostly in the proximal tubules, thereby inducing tubular injury and tubulointerstitial nephritis. To elucidate the role of leptospira outer membrane proteins in tubulointerstitial nephritis, outer membrane proteins from pathogenic Leptospira shermani and nonpathogenic Leptospira patoc extracted by Triton X-114 were administered to cultured mouse proximal tubule cells. A dose-dependent increase of monocyte chemoattractant protein-1 (MCP-1), RANTES, nitrite, and tumor necrosis factor-alpha (TNF-alpha) in the culture supernatant was observed 48 h after incubating Leptospira shermani outer membrane proteins with mouse proximal tubule cells. RT competitive-PCR experiments showed that Leptospira shermani outer membrane proteins (0.2 microg/ml) increased the expression of MCP-1, nitric oxide synthase (iNOS), RANTES, and TNF-alpha mRNA by 3.0-, 9.4-, 2.5-, and 2.5-fold, respectively, when compared with untreated cells. Outer membrane proteins extract from avirulent Leptospira patoc did not induce significant effects. The pathogenic outer membrane proteins extract contain a major component of a 32-kD lipoprotein (LipL32), which is absent in the nonpathogenic leptospira outer membrane. An antibody raised against LipL32 prevented the stimulatory effect of Leptospira shermani outer membrane proteins extract on MCP-1 and iNOS mRNA expression in cultured proximal tubule cells, whereas recombinant LipL32 significantly stimulated the expression of MCP-1 and iNOS mRNAs and augmented nuclear binding of nuclear factor-kappaB (NF-kappaB) and AP-1 transcription factors in proximal tubule cells. An antibody raised against LipL32 also blunted the effects induced by the recombinant LipL32. This study demonstrates that LipL32 is a major component of pathogenic leptospira outer membrane proteins involved in the pathogenesis of tubulointerstitial nephritis.

  9. X radiation effect in the proximal contorted renal tubules of mice

    International Nuclear Information System (INIS)

    Pacheco, I.P.

    1977-01-01

    Exposing C 57B1, 100 days old, mice to X-ray radiation in doses of 150, 300 and 400 R was observed in the proximal contorted renal tubules. An early appearance of unspecific alterations which are peculiar to ageing [pt

  10. Role of calcium in the dopaminergic effect on the proximal convoluted tubule of rat kidney

    International Nuclear Information System (INIS)

    Chan, Y.L.; Chatsudthipong, V.; Su-Tsai, S.M.; von Riotte, A.

    1986-01-01

    Microperfusion studies have shown that dopamine inhibits fluid and bicarbonate absorption in the rate proximal tubule. These studies are designed to examine the cellular mechanism underlying the proximal cellular response to dopamine action. In the isolated proximal cells, dopamine, in the concentration of 10 -6 M or less, had no effect on cAMP production. However, dopamine could increase cytosolic calcium concentration (from 90 nM to 210 nM) as measured by fluorospectrometry with fura-2 as a calcium indicator. Ca-45 flux studies have shown that dopamine could increase initial influx but not the steady state uptake of Ca. Dopamine could also increase efflux of Ca. In situ microperfusion of proximal tubule and peritubular capillaries has demonstrated that Ca ionophore, A23187 (10 -6 M), could simulate the inhibitory effects of dopamine on fluid and biocarbonate absorption. There was no additive effect observed when both agents were added together in the capillary perfusate. Removal of calcium from the perfusate could partially blunt the effect of dopamine. These results suggest that intracellular calcium plays a crucial role in the dopaminergic regulation of proximal tubular transport

  11. Characterization of rPEPT2-mediated Gly-Sar transport parameters in the rat kidney proximal tubule cell line SKPT-0193 cl.2 cultured in basic growth media

    DEFF Research Database (Denmark)

    Bravo, Silvina A; Nielsen, Carsten Uhd; Frokjaer, Sven

    2005-01-01

    The rat proximal kidney tubule cell line SKPT-0193 cl.2 (SKPT) expresses the di-/tripeptide transporter PEPT2 (rPEPT2) and has been used to study PEPT2-mediated transport. Traditionally, SKPT cells have been cultured in growth media supplemented with epidermal growth factor (EGF), apotransferrin,...

  12. Cyclophilin B interacts with sodium-potassium ATPase and is required for pump activity in proximal tubule cells of the kidney.

    Science.gov (United States)

    Suñé, Guillermo; Sarró, Eduard; Puigmulé, Marta; López-Hellín, Joan; Zufferey, Madeleine; Pertel, Thomas; Luban, Jeremy; Meseguer, Anna

    2010-11-10

    Cyclophilins (Cyps), the intracellular receptors for Cyclosporine A (CsA), are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions are inhibited upon CsA binding. Albeit its great benefits as immunosuppressant, the use of CsA has been limited by undesirable nephrotoxic effects, including sodium retention, hypertension, hyperkalemia, interstial fibrosis and progressive renal failure in transplant recipients. In this report, we focused on the identification of novel CypB-interacting proteins to understand the role of CypB in kidney function and, in turn, to gain further insight into the molecular mechanisms of CsA-induced toxicity. By means of yeast two-hybrid screens with human kidney cDNA, we discovered a novel interaction between CypB and the membrane Na/K-ATPase β1 subunit protein (Na/K-β1) that was confirmed by pull-down, co-immunoprecipitation and confocal microscopy, in proximal tubule-derived HK-2 cells. The Na/K-ATPase pump, a key plasma membrane transporter, is responsible for maintenance of electrical Na+ and K+ gradients across the membrane. We showed that CypB silencing produced similar effects on Na/K-ATPase activity than CsA treatment in HK-2 cells. It was also observed an enrichment of both alpha and beta subunits in the ER, what suggested a possible failure on the maturation and routing of the pump from this compartment towards the plasma membrane. These data indicate that CypB through its interaction with Na/K-β1 might regulate maturation and trafficking of the pump through the secretory pathway, offering new insights into the relationship between cyclophilins and the nephrotoxic effects of CsA.

  13. Local pH domains regulate NHE3-mediated Na+ reabsorption in the renal proximal tubule

    Science.gov (United States)

    Burford, James L.; McDonough, Alicia A.; Holstein-Rathlou, Niels-Henrik; Peti-Peterdi, Janos

    2014-01-01

    The proximal tubule Na+/H+ exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base of the brush border, where NHE3 activity is reduced. This NHE3 redistribution is assumed to provoke pressure natriuresis; however, it is unclear how NHE3 redistribution per se reduces NHE3 activity. To investigate if the distribution of NHE3 in the brush border can change the reabsorption rate, we constructed a spatiotemporal mathematical model of NHE3-mediated Na+ reabsorption across a proximal tubule cell and compared the model results with in vivo experiments in rats. The model predicts that when NHE3 is localized exclusively at the base of the brush border, it creates local pH microdomains that reduce NHE3 activity by >30%. We tested the model's prediction experimentally: the rat kidney cortex was loaded with the pH-sensitive fluorescent dye BCECF, and cells of the proximal tubule were imaged in vivo using confocal fluorescence microscopy before and after an increase of blood pressure by ∼50 mmHg. The experimental results supported the model by demonstrating that a rise of blood pressure induces the development of pH microdomains near the bottom of the brush border. These local changes in pH reduce NHE3 activity, which may explain the pressure natriuresis response to NHE3 redistribution. PMID:25298526

  14. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Justin J. Lee

    2017-10-01

    Full Text Available Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH, active vitamin D3, and fibroblast growth factor 23 (FGF23. The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms responsible for phosphate reclamation are well described, and emerging work is delineating the molecular identity of the paracellular shunt wherein calcium permeates the proximal tubular epithelium. Significant experimental work has delineated the molecular effects of PTH and FGF23 on these processes as well as their regulation of active vitamin D3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance.

  15. Urinary loss of glucose, phosphate, and protein by diffusion into proximal straight tubules injured by D-serine and maleic acid

    International Nuclear Information System (INIS)

    Carone, F.A.; Nakamura, S.; Goldman, B.

    1985-01-01

    In several models of acute renal failure leakage of glomerular filtrate out of the tubule is an important pathogenetic mechanism; however, bidirectional diffusion of solute to account for certain pathophysiologic features of acute renal failure has received meager attention. Using micropuncture and clearance methods, the authors assessed sequentially leakage of solutes and inulin across proximal straight tubules (PST) injured by two nephrotoxins. In d-serine-treated rats with extensive necrosis of PST, the basis for glucosuria and tubular leakage of inulin was studied. Glucose absorption by the proximal convoluted tubule and glucose delivery to the PST were normal, but glucose delivery to the distal tubule was increased nearly 8-fold, indicating diffusion of glucose from interstitial to tubular luminal fluid across the necrotic PST. Total kidney inulin clearance was greatly reduced, but single nephron glomerular filtration rate, based on proximal convoluted tubule samples, was normal, indicating tubular loss of inulin. Urinary recovery of [ 14 C]inulin infused into tubular lumina revealed that proximal convoluted tubule and distal tubule were impermeable to inulin and that inulin diffused out of the necrotic PST. The progressive return over 6 days of tubular impermeability for inulin correlated with relining of PST with new cells. In maleic acid-treated rats the site and extent of tubular necrosis and the nature of urinary loss of solutes were studied. Microdissection revealed that maleic acid caused limited necrosis of PST which averaged 7.4% of total proximal tubular length. Increased urinary excretion of protein, phosphate, and glucose and increased tubular permeability to microinfused [ 14 C]inulin occurred with the onset of PST necrosis, and return of these abnormalities to normal correlated with the degree of cellular repair of the PST

  16. Cyclophilin B interacts with sodium-potassium ATPase and is required for pump activity in proximal tubule cells of the kidney.

    Directory of Open Access Journals (Sweden)

    Guillermo Suñé

    Full Text Available Cyclophilins (Cyps, the intracellular receptors for Cyclosporine A (CsA, are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions are inhibited upon CsA binding. Albeit its great benefits as immunosuppressant, the use of CsA has been limited by undesirable nephrotoxic effects, including sodium retention, hypertension, hyperkalemia, interstial fibrosis and progressive renal failure in transplant recipients. In this report, we focused on the identification of novel CypB-interacting proteins to understand the role of CypB in kidney function and, in turn, to gain further insight into the molecular mechanisms of CsA-induced toxicity. By means of yeast two-hybrid screens with human kidney cDNA, we discovered a novel interaction between CypB and the membrane Na/K-ATPase β1 subunit protein (Na/K-β1 that was confirmed by pull-down, co-immunoprecipitation and confocal microscopy, in proximal tubule-derived HK-2 cells. The Na/K-ATPase pump, a key plasma membrane transporter, is responsible for maintenance of electrical Na+ and K+ gradients across the membrane. We showed that CypB silencing produced similar effects on Na/K-ATPase activity than CsA treatment in HK-2 cells. It was also observed an enrichment of both alpha and beta subunits in the ER, what suggested a possible failure on the maturation and routing of the pump from this compartment towards the plasma membrane. These data indicate that CypB through its interaction with Na/K-β1 might regulate maturation and trafficking of the pump through the secretory pathway, offering new insights into the relationship between cyclophilins and the nephrotoxic effects of CsA.

  17. Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism

    NARCIS (Netherlands)

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Lamers, Wouter H.; Chaudhry, Farrukh A.; Verlander, Jill W.; Weiner, I. David

    2016-01-01

    Glutamine synthetase (GS) catalyzes the recycling of NH4 (+) with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of

  18. Data on Na,K-ATPase in primary cultures of renal proximal tubule cells treated with catecholamines

    Directory of Open Access Journals (Sweden)

    Mary Taub

    2016-03-01

    Full Text Available This data article is concerned with chronic regulation of Na,K-ATPase by catecholamines. After a chronic treatment, inhibition of Na,K-ATPase activity was observed in cultures with dopamine, while a stimulation was observed in cultures treated with norepinephrine. Following a chronic incubation with guanabenz, an α adrenergic agonist, an increase in Na,K-ATPase α and β subunit mRNAs was observed. This data supports the research article entitled, “Renal proximal tubule Na, K-ATPase is controlled by CREB regulated transcriptional coactivators as well as salt inducible kinase 1” (Taub et al. 2015 [1]. Keywords: Catecholamines, Kidney, Proximal tubule, Na,K-ATPase, Chronic

  19. A telomerase immortalized human proximal tubule cell line with a truncation mutation (Q4004X in polycystin-1.

    Directory of Open Access Journals (Sweden)

    Brittney-Shea Herbert

    Full Text Available Autosomal dominant polycystic kidney disease (ADPKD is associated with a variety of cellular phenotypes in renal epithelial cells. Cystic epithelia are secretory as opposed to absorptive, have higher proliferation rates in cell culture and have some characteristics of epithelial to mesenchymal transitions. In this communication we describe a telomerase immortalized cell line that expresses proximal tubule markers and is derived from renal cysts of an ADPKD kidney. These cells have a single detectable truncating mutation (Q4004X in polycystin-1. These cells make normal appearing but shorter cilia and fail to assemble polycystin-1 in the cilia, and less uncleaved polycystin-1 in membrane fractions. This cell line has been maintained in continuous passage for over 35 passages without going into senescence. Nephron segment specific markers suggest a proximal tubule origin for these cells and the cell line will be useful to study mechanistic details of cyst formation in proximal tubule cells.

  20. Substrate modulation of fatty acid effects on energization and respiration of kidney proximal tubules during hypoxia/reoxygenation.

    Directory of Open Access Journals (Sweden)

    Anja Bienholz

    Full Text Available Kidney proximal tubules subjected to hypoxia/reoxygenation develop a nonesterified fatty acid-induced energetic deficit characterized by persistent partial mitochondrial deenergization that can be prevented and reversed by citric acid cycle substrates. To further assess the role of competition between fatty acids and substrates on inner membrane substrate carriers in the deenergization and the contribution to deenergization of fatty acid effects on respiratory function, digitonin-permeabilized rabbit and mouse tubules were studied using either addition of exogenous oleate after control normoxic incubation or increases of endogenous fatty acids produced by hypoxia/reoxygenation. The results demonstrated major effects of matrix oxaloacetate accumulation on succinate-supported energization and respiration and their modification by fatty acids. Improvements of energization in the presence of fatty acids by glutamate were shown to result predominantly from lowering matrix oxaloacetate rather than from amelioration of transmembrane cycling of fatty acids and uncoupling. Mouse tubules had 2.5 fold higher rates of succinate utilization, which resulted in stronger effects of oxaloacetate accumulation than rabbit tubules. Hypoxia/reoxygenation induced respiratory inhibition that was more severe for complex I-dependent substrates. Fatty acids themselves did not acutely contribute to this respiratory inhibition, but lowering them during 60 min. reoxygenation to allow recovery of ATP during that period alleviated it. These data clarify the basis for the nonesterified fatty acid-induced mitochondrial energetic deficit in kidney proximal tubules that impairs structural and functional recovery and provide insight into interactions that need to be considered in the design of substrate-based interventions to improve mitochondrial function.

  1. Thiazolidinediones enhance sodium-coupled bicarbonate absorption from renal proximal tubules via PPARγ-dependent nongenomic signaling.

    Science.gov (United States)

    Endo, Yoko; Suzuki, Masashi; Yamada, Hideomi; Horita, Shoko; Kunimi, Motoei; Yamazaki, Osamu; Shirai, Ayumi; Nakamura, Motonobu; Iso-O, Naoyuki; Li, Yuehong; Hara, Masumi; Tsukamoto, Kazuhisa; Moriyama, Nobuo; Kudo, Akihiko; Kawakami, Hayato; Yamauchi, Toshimasa; Kubota, Naoto; Kadowaki, Takashi; Kume, Haruki; Enomoto, Yutaka; Homma, Yukio; Seki, George; Fujita, Toshiro

    2011-05-04

    Thiazolidinediones (TZDs) improve insulin resistance by activating a nuclear hormone receptor, peroxisome proliferator-activated receptor γ (PPARγ). However, the use of TZDs is associated with plasma volume expansion through a mechanism that remains to be clarified. Here we showed that TZDs rapidly stimulate sodium-coupled bicarbonate absorption from the renal proximal tubule in vitro and in vivo. TZD-induced transport stimulation is dependent on PPARγ-Src-EGFR-ERK and observed in rat, rabbit and human, but not in mouse proximal tubules where Src-EGFR is constitutively activated. The existence of PPARγ-Src-dependent nongenomic signaling, which requires the ligand-binding ability, but not the transcriptional activity of PPARγ, is confirmed in mouse embryonic fibroblast cells. The enhancement of the association between PPARγ and Src by TZDs supports an indispensable role of Src in this signaling. These results suggest that the PPARγ-dependent nongenomic stimulation of renal proximal transport is also involved in TZD-induced volume expansion. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Epidermal growth factor decreases PEPT2 transport capacity and expression in the rat kidney proximal tubule cell line SKPT0193 cl.2

    DEFF Research Database (Denmark)

    Bravo, Silvina A; Nielsen, Carsten Uhd; Amstrup, Jan

    2004-01-01

    by studies of apical uptake of [14C]glycylsarcosine, rPepT2 mRNA levels, and immunostaining of SKPT cells with a rPEPT2-specific antibody. On the contrary, apical uptake of glucose and lysine was increased in EGF-treated cells, indicating that EGF was not acting generally to decrease apical nutrient uptake...... mechanisms in the proximal tubule cells. Our findings indicate that EGF decreases rPEPT2 expression by lowering transcription of the rat PepT2 gene or by decreasing rat PepT2 mRNA stability. Previous investigators routinely used SKPT cell culture media with a high (10 ng/ml) EGF concentration. Our study...

  3. Mechanism of cisplatin proximal tubule toxicity revealed by integrating transcriptomics, proteomics, metabolomics and biokinetics

    NARCIS (Netherlands)

    Wilmes, Anja; Bielow, Chris; Ranninger, Christina; Bellwon, Patricia; Aschauer, Lydia; Limonciel, Alice; Chassaigne, Hubert; Kristl, Theresa; Aiche, Stephan; Huber, Christian G; Guillou, Claude; Hewitt, Philipp; Leonard, Martin O; Dekant, Wolfgang; Bois, Frederic Y; Jennings, Paul

    2015-01-01

    Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of solid tumours. The major dose-limiting factor is nephrotoxicity, in particular in the proximal tubule. Here, we use an integrated omics approach, including transcriptomics, proteomics and metabolomics coupled to

  4. NMR-based urine analysis in rats: prediction of proximal tubule kidney toxicity and phospholipidosis.

    Science.gov (United States)

    Lienemann, Kai; Plötz, Thomas; Pestel, Sabine

    2008-01-01

    The aim of safety pharmacology is early detection of compound-induced side-effects. NMR-based urine analysis followed by multivariate data analysis (metabonomics) identifies efficiently differences between toxic and non-toxic compounds; but in most cases multiple administrations of the test compound are necessary. We tested the feasibility of detecting proximal tubule kidney toxicity and phospholipidosis with metabonomics techniques after single compound administration as an early safety pharmacology approach. Rats were treated orally, intravenously, inhalatively or intraperitoneally with different test compounds. Urine was collected at 0-8 h and 8-24 h after compound administration, and (1)H NMR-patterns were recorded from the samples. Variation of post-processing and feature extraction methods led to different views on the data. Support Vector Machines were trained on these different data sets and then aggregated as experts in an Ensemble. Finally, validity was monitored with a cross-validation study using a training, validation, and test data set. Proximal tubule kidney toxicity could be predicted with reasonable total classification accuracy (85%), specificity (88%) and sensitivity (78%). In comparison to alternative histological studies, results were obtained quicker, compound need was reduced, and very importantly fewer animals were needed. In contrast, the induction of phospholipidosis by the test compounds could not be predicted using NMR-based urine analysis or the previously published biomarker PAG. NMR-based urine analysis was shown to effectively predict proximal tubule kidney toxicity after single compound administration in rats. Thus, this experimental design allows early detection of toxicity risks with relatively low amounts of compound in a reasonably short period of time.

  5. Adaptive regulation of taurine and beta-alanine uptake in a human kidney cell line from the proximal tubule

    DEFF Research Database (Denmark)

    Jessen, H; Jacobsen, Christian

    1997-01-01

    1. The underlying mechanisms involved in the adaptive regulation of beta-amino acid uptake in the human proximal tubule were examined by use of an immortalized human embryonic kidney epithelial cell line (IHKE). 2. The results indicated that the adaptive response to maintain whole-body taurine...

  6. The role of renal proximal tubule P450 enzymes in chloroform-induced nephrotoxicity: Utility of renal specific P450 reductase knockout mouse models

    International Nuclear Information System (INIS)

    Liu, Senyan; Yao, Yunyi; Lu, Shijun; Aldous, Kenneth; Ding, Xinxin; Mei, Changlin; Gu, Jun

    2013-01-01

    The kidney is a primary target for numerous toxic compounds. Cytochrome P450 enzymes (P450) are responsible for the metabolic activation of various chemical compounds, and in the kidney are predominantly expressed in proximal tubules. The aim of this study was to test the hypothesis that renal proximal tubular P450s are critical for nephrotoxicity caused by chemicals such as chloroform. We developed two new mouse models, one having proximal tubule-specific deletion of the cytochrome P450 reductase (Cpr) gene (the enzyme required for all microsomal P450 activities), designated proximal tubule-Cpr-null (PTCN), and the other having proximal tubule-specific rescue of CPR activity with the global suppression of CPR activity in all extra-proximal tubular tissues, designated extra-proximal tubule-Cpr-low (XPT-CL). The PTCN, XPT-CL, Cpr-low (CL), and wild-type (WT) mice were treated with a single oral dose of chloroform at 200 mg/kg. Blood, liver and kidney samples were obtained at 24 h after the treatment. Renal toxicity was assessed by measuring BUN and creatinine levels, and by pathological examination. The blood and tissue levels of chloroform were determined. The severity of toxicity was less in PTCN and CL mice, compared with that of WT and XPT-CL mice. There were no significant differences in chloroform levels in the blood, liver, or kidney, between PTCN and WT mice, or between XPT-CL and CL mice. These findings indicate that local P450-dependent activities play an important role in the nephrotoxicity induced by chloroform. Our results also demonstrate the usefulness of these novel mouse models for studies of chemical-induced kidney toxicity. - Highlights: • New mouse models were developed with varying P450 activities in the proximal tubule. • These mouse models were treated with chloroform, a nephrotoxicant. • Studies showed the importance of local P450s in chloroform-induced nephrotoxicity

  7. N-domain angiotensin-I converting enzyme is expressed in immortalized mesangial, proximal tubule and collecting duct cells.

    Science.gov (United States)

    Mei Wang, Pamella Huey; Andrade, Maria Claudina; Quinto, Beata Marie Redublo; Di Marco, Giovana; Mortara, Renato Arruda; Vio, Carlos P; Casarini, Dulce Elena

    2015-01-01

    Somatic ACE (sACE) is found in glomerulus, proximal tubule and excreted in urine. We hypothesized that N-domain ACE can also be found at these sites. ACE profile was analyzed in mesangial (IMC), proximal (LLC-PK1), distal tubule (MDCK) and collecting duct (IMCD) cells. Cell lysate and culture medium were submitted to gel filtration chromatography, which separated two peaks with ACE activity from cells and medium, except from distal tubule. The first had a high molecular weight and the second, a lower one (65 kDa; N-domain ACE). We focused on N-domain ACE purification and characterization from LLC-PK1. Total LLC-PK1 N-domain ACE purification was achieved by ion-exchange chromatography, which presented only one peak with ACE activity, denominated ACE(int2A). ACE(int2A) activity was influenced by pH, NaCl and temperature. The purified enzyme was inhibited by Captopril and hydrolyzed AngI, Ang1-7 and AcSDKP. Its ability to hydrolyze AcSDKP characterized it as an N-domain ACE. ACE(int2A) also presented high amino acid sequence homology with the N-terminal part of sACE from mouse, rat, human and rabbit. The presence of secreted and intracellular N-domain ACE and sACE in IMC, LLC-PK1 and IMCD cells confirmed our studies along the nephron. We identified, purified and characterized N-domain ACE from LLC-PK1. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Subcellular distribution of folate and folate binding protein in renal proximal tubules

    International Nuclear Information System (INIS)

    Sharkey, C.; Hjelle, J.T.; Selhub, J.

    1986-01-01

    High affinity folate binding protein (FBP) found in brush border membranes derived from renal cortices is thought to be involved in the renal conservation of folate. To examine the mechanisms of folate recovery, the subcellular distribution of FBP and 3 H-folate in rabbit renal proximal tubules (PT) was examined using analytical cell fractionation techniques. Tubules contain 3.41 +/- 0.32 picomoles FBP/mg protein (X +/- S.D.; n = 5). Postnuclear supernates (PNS) of PT were layered atop Percoll-sucrose gradients, centrifuged, fractions collected and assayed for various marker enzymes and FBP. Pooled fractions from such gradients were subsequently treated with digitonin and centrifuged in a stoichiometric manner with the activity of the microvillar enzyme, alanylaminopeptidase (AAP); excess FBP distributed with more buoyant particles. Infusion of 3 H-folate into rabbit kidneys followed by tubule isolation and fractionation revealed a time dependent shift in distribution of radiolabel from the AAP-rich gradient fractions to a region containing more buoyant particles; radiolevel was not associated with lysosomal markers. EM-radioautography revealed grains over intracellular vesicles. These results are consistent with the hypothesis that folate is recovered by a process involving receptor-mediated endocytosis or transcytosis

  9. Renal compensation to chronic hypoxic hypercapnia: downregulation of pendrin and adaptation of the proximal tubule.

    NARCIS (Netherlands)

    Seigneux, S. de; Malte, H.; Dimke, H.; Frokiaer, J.; Nielsen, S.; Frische, S.

    2007-01-01

    The molecular basis for the renal compensation to respiratory acidosis and specifically the role of pendrin in this condition are unclear. Therefore, we studied the adaptation of the proximal tubule and the collecting duct to respiratory acidosis. Male Wistar-Hannover rats were exposed to either

  10. Transport of salicylate in proximal tubule (S2 segment) isolated from rabbit kidney

    International Nuclear Information System (INIS)

    Schild, L.; Roch-Ramel, F.

    1988-01-01

    The secretory and the reabsorptive transport of salicylate was studied in the isolated and perfused rabbit proximal tubule (S 2 segment). Salicylate secretion (J sal b→l ) fulfilled the criteria for a carrier-mediated transport system: J sal b→l was saturable, was reversibly inhibited by probenecid, and occurred against a concentration gradient. The K m and V max for this secretory transport were 80 μM and 3,200 fmol·min -1 ·mm -1 , respectively. At luminal pH of 7.4 and 6.6, salicylate reabsorption (J sal l→b ) was low. J sal l→b was stimulated by increasing the bath Pco 2 or by removing basolateral HCO 3 - ; J sal l→b was inhibited by ethoxyzolamide and by SITS in the bath. The results indicate that salicylate reabsorption depends on H + secretion, consistent with reabsorption by simple nonionic diffusion. When salicylate was present in the lumen only, J sal l→b increased after inhibition of the secretory transport by adding ouabain or probenecid in the bath or by lowering the bath temperature. These results are compatible with luminal recycling of salicylate, and suggest the presence of a mediated secretory transporter located at the luminal membrane

  11. P-glycoprotein-deficient mice have proximal tubule dysfunction but are protected against ischemic renal injury

    NARCIS (Netherlands)

    Huls, M.; Kramers, C.; Levtchenko, E.N.; Wilmer, M.J.G.; Dijkman, H.B.P.M.; Kluijtmans, L.A.J.; Hoorn, J.W.A. van der; Russel, F.G.M.; Masereeuw, R.

    2007-01-01

    The multidrug resistance gene 1 product, P-glycoprotein (P-gp), is expressed in several excretory organs, including the apical membrane of proximal tubules. After inducing acute renal failure, P-gp expression is upregulated and this might be a protective function by pumping out toxicants and harmful

  12. Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells.

    Science.gov (United States)

    Massey, Katherine J; Li, Quanwen; Rossi, Noreen F; Keezer, Susan M; Mattingly, Raymond R; Yingst, Douglas R

    2016-02-01

    How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser(938) were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K · mg protein(-1) · min(-1) and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser(938) is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells.

  13. Effects of angiotensin II and ionomycin on fluid and bicarbonate absorption in the rat proximal tubule

    International Nuclear Information System (INIS)

    Chatsudthipong, V.; Chan, Y.L.

    1986-01-01

    Microperfusion of proximal convoluted tubule(PCT) and peritubular capillaries was performed to examine the effects of angiotensin II(Ang II) and ionomycin on fluid and bicarbonate absorption. Bicarbonate was determined by microcalorimetry and C-14 inulin was used as a volume marker. The rates of bicarbonate absorption (JHCO 3 ) was 143 peq/min x mm and fluid absorption(Jv) was 2.70 nl/min x mm, when PCT and capillary perfusate contained normal Ringer solution. Addition of Ang II (10 -6 M) to the capillary perfusate caused reductions of JHCO 3 and Jv by 35%. A similar effect was observed when ionomycin was added to the capillary perfusate. Ang II antagonist, (Sar 1 , Ile 8 )-Angiotensin II(10 -6 M), completely blocked the inhibitory effect of Ang II on Jv and JHCO 3 . Removal of calcium from both luminal and capillary perfusate did not change the effect of Ang II on Jv and JHCO 3 . Our results indicate that Ang II inhibits the sodium-hydrogen exchanger in the proximal tubule via interacting with angiotensin receptor. The mechanism of Ang II action may involve mobilization of intracellular calcium

  14. The proximal straight tubule (PST) basolateral cell membrane water channel: selectivity characteristics.

    Science.gov (United States)

    Gutiérrez, A M; González, E; Echevarría, M; Hernández, C S; Whittembury, G

    1995-02-01

    Proximal straight tubules (PST) were dissected from rabbit kidneys, held by crimping pipettes in a chamber and bathed in a buffered isosmotic (295 mOsm/kg) solution containing 200 mM mannitol (MBS). Changes in tubule diameter were monitored on line with an inverted microscope, TV camera and image processor. The PST were then challenged for 20 sec with MBS made 35 mOsm/kg hyperosmotic by addition of either NaCl, KCl, mannitol (M), glycerol (G), ethylene glycol (E), glycine (g), urea (U), acetamide (A) or formamide (F). With NaCl, KCl, M, G, E, g, U, and A, tubules shrunk osmometrically within 0.5 sec and remained shrunk for as long as 20 sec without recovering their original volume (sometimes A showed some recovery). PST barely shrunk with F and quickly recovered their original volume. The permeability coefficients were 0 microns/sec (NaCl, M, g, E and U), 1 micron/sec (A), 84 microns/sec (F) and 0.02 micron/sec (G). The reflection coefficients sigma = 1.0 (NaCl, KCl, M, G, E, g and U), 0.95 (A) and 0.62 (F). Similar sigma values were obtained by substituting 200 mOsm/kg M in MBS by either NaCl, KCl, G, E, g, U, a or F. The olive oil/water partition coefficients are 5 (M), 15 (U), 85 (A) and 75 (F) (all x 10(-5)). Thus, part of F permeates the cell membrane through the lipid bilayer. The probing molecules van der Waals diameters are 7.4 x 8.2 x 12.0 (M), 3.6 x 5.2 x 5.4 (U), 3.8 x 5.2 x 5.4 (A) and (3.4 x 4.5 x 5.4 (F) A.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Acute hypotension induced by aortic clamp vs. PTH provokes distinct proximal tubule Na+ transporter redistribution patterns

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; Lin, Harrison W

    2004-01-01

    . This study aimed to determine the effects of acute hypotension, induced by aortic clamp or by high-dose PTH (100 microg PTH/kg), on renal hemodynamics and proximal tubule Na/H exchanger isoform 3 (NHE3) and type IIa Na-P(i) cotransporter protein (NaPi2) distribution. Subcellular distribution was analyzed...... clearance. There was, however, no significant change in glomerular filtration rate (GFR) or subcellular distribution of NHE3 and NaPi2. In contrast, high-dose PTH rapidly (

  16. Diglycolic acid is the nephrotoxic metabolite in diethylene glycol poisoning inducing necrosis in human proximal tubule cells in vitro.

    Science.gov (United States)

    Landry, Greg M; Martin, Sarah; McMartin, Kenneth E

    2011-11-01

    Diethylene glycol (DEG), a solvent and chemical intermediate, can produce an acute toxic syndrome, the hallmark of which is acute renal failure due to cortical tubular degeneration and proximal tubular necrosis. DEG is metabolized to two primary metabolites, 2-hydroxyethoxyacetic acid (2-HEAA) and diglycolic acid (DGA), which are believed to be the proximate toxicants. The precise mechanism of toxicity has yet to be elucidated, so these studies were designed to determine which metabolite was responsible for the proximal tubule cell death. Human proximal tubule (HPT) cells in culture, obtained from normal cortical tissue and passaged 3-6 times, were incubated with increasing concentrations of DEG, 2-HEAA, or DGA separately and in combination for 48 h at pH 6 or 7.4, and various parameters of necrotic and apoptotic cell death were measured. DEG and 2-HEAA did not produce any cell death. DGA produced dose-dependent necrosis at concentrations above 25 mmol/l. DGA did not affect caspase-3 activity and increased annexin V staining only in propidium iodide-stained cells. Hence, DGA induced necrosis, not apoptosis, as corroborated by severe depletion of cellular adenosine triphosphate levels. DGA is structurally similar to citric acid cycle intermediates that are taken up by specific transporters in kidney cells. HPT cells, incubated with N-(p-amylcinnamoyl)anthranilic acid, a sodium dicarboxylate-1 transporter inhibitor showed significantly decreased cell death compared with DGA alone. These studies demonstrate that DGA is the toxic metabolite responsible for DEG-induced proximal tubular necrosis and suggest a possible transporter-mediated uptake of DGA leading to toxic accumulation and cellular dysfunction.

  17. Downregulation of the S1P Transporter Spinster Homology Protein 2 (Spns2 Exerts an Anti-Fibrotic and Anti-Inflammatory Effect in Human Renal Proximal Tubular Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Olivier Blanchard

    2018-05-01

    Full Text Available Sphingosine kinase (SK catalyses the formation of sphingosine 1-phosphate (S1P, which acts as a key regulator of inflammatory and fibrotic reactions, mainly via S1P receptor activation. Here, we show that in the human renal proximal tubular epithelial cell line HK2, the profibrotic mediator transforming growth factor β (TGFβ induces SK-1 mRNA and protein expression, and in parallel, it also upregulates the expression of the fibrotic markers connective tissue growth factor (CTGF and fibronectin. Stable downregulation of SK-1 by RNAi resulted in the increased expression of CTGF, suggesting a suppressive effect of SK-1-derived intracellular S1P in the fibrotic process, which is lost when SK-1 is downregulated. In a further approach, the S1P transporter Spns2, which is known to export S1P and thereby reduces intracellular S1P levels, was stably downregulated in HK2 cells by RNAi. This treatment decreased TGFβ-induced CTGF and fibronectin expression, and it abolished the strong induction of the monocyte chemotactic protein 1 (MCP-1 by the pro-inflammatory cytokines tumor necrosis factor (TNFα and interleukin (IL-1β. Moreover, it enhanced the expression of aquaporin 1, which is an important water channel that is expressed in the proximal tubules, and reverted aquaporin 1 downregulation induced by IL-1β/TNFα. On the other hand, overexpression of a Spns2-GFP construct increased S1P secretion and it resulted in enhanced TGFβ-induced CTGF expression. In summary, our data demonstrate that in human renal proximal tubular epithelial cells, SK-1 downregulation accelerates an inflammatory and fibrotic reaction, whereas Spns2 downregulation has an opposite effect. We conclude that Spns2 represents a promising new target for the treatment of tubulointerstitial inflammation and fibrosis.

  18. Reversible effects of acute hypertension on proximal tubule sodium transporters

    DEFF Research Database (Denmark)

    Zhang, Y; Magyar, C E; Norian, J M

    1998-01-01

    Acute hypertension provokes a rapid decrease in proximal tubule sodium reabsorption with a decrease in basolateral membrane sodium-potassium-ATPase activity and an increase in the density of membranes containing apical membrane sodium/hydrogen exchangers (NHE3) [Y. Zhang, A. K. Mircheff, C. B....... Renal cortex lysate was fractionated on sorbitol gradients. Basolateral membrane sodium-potassium-ATPase activity (but not subunit immunoreactivity) decreased one-third to one-half after BP was elevated and recovered after BP was normalized. After BP was elevated, 55% of the apical NHE3 immunoreactivity......, smaller fractions of sodium-phosphate cotransporter immunoreactivity, and apical alkaline phosphatase and dipeptidyl-peptidase redistributed to membranes of higher density enriched in markers of the intermicrovillar cleft (megalin) and endosomes (Rab 4 and Rab 5), whereas density distributions...

  19. Mechanism of cisplatin proximal tubule toxicity revealed by integrating transcriptomics, proteomics, metabolomics and biokinetics.

    Science.gov (United States)

    Wilmes, Anja; Bielow, Chris; Ranninger, Christina; Bellwon, Patricia; Aschauer, Lydia; Limonciel, Alice; Chassaigne, Hubert; Kristl, Theresa; Aiche, Stephan; Huber, Christian G; Guillou, Claude; Hewitt, Philipp; Leonard, Martin O; Dekant, Wolfgang; Bois, Frederic; Jennings, Paul

    2015-12-25

    Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of solid tumours. The major dose-limiting factor is nephrotoxicity, in particular in the proximal tubule. Here, we use an integrated omics approach, including transcriptomics, proteomics and metabolomics coupled to biokinetics to identify cell stress response pathways induced by cisplatin. The human renal proximal tubular cell line RPTEC/TERT1 was treated with sub-cytotoxic concentrations of cisplatin (0.5 and 2 μM) in a daily repeat dose treating regime for up to 14 days. Biokinetic analysis showed that cisplatin was taken up from the basolateral compartment, transported to the apical compartment, and accumulated in cells over time. This is in line with basolateral uptake of cisplatin via organic cation transporter 2 and bioactivation via gamma-glutamyl transpeptidase located on the apical side of proximal tubular cells. Cisplatin affected several pathways including, p53 signalling, Nrf2 mediated oxidative stress response, mitochondrial processes, mTOR and AMPK signalling. In addition, we identified novel pathways changed by cisplatin, including eIF2 signalling, actin nucleation via the ARP/WASP complex and regulation of cell polarization. In conclusion, using an integrated omic approach together with biokinetics we have identified both novel and established mechanisms of cisplatin toxicity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman’s capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium

    OpenAIRE

    Tabatabai, Niloofar M.; North, Paula E.; Regner, Kevin R.; Kumar, Suresh N.; Duris, Christine B.; Blodgett, Amy B.

    2014-01-01

    In kidney nephron, parietal epithelial cells line the Bowman’s capsule and function as a permeability barrier for the glomerular filtrate. Bowman’s capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman’s capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane of epithelial cells in the...

  1. The effect of L-cysteine on the portion-selective uptake of cadmium in the renal proximal tubule

    International Nuclear Information System (INIS)

    Murakami, Masataka; Sano, Kenichi; Webb, M.

    1987-01-01

    Cadmium (Cd), co-administered with an excess of L-cysteine, accumulates rapidly in the kidneys of the rat. After subcutaneous (s.c.) injection of 3 μmol CdCl 2 /kg body wt the concentrations of Cd in the blood and kidneys increase with the dose of cysteine over the range 0.06-5.0 mmol/kg body wt. At cysteine doses of less than 1.5 mmol/kg body wt the ratio of the concentrations of Cd in the outer medulla and cortex of the kidney remains the same as that after the injection of Cd alone. This ratio, however, is more than doubled at dose levels of 5-10 mmol cysteine/kg body wt. Hepatic uptake of Cd is unaffected by doses of cysteine below 1.5 mmol/kg body wt but decreases markedly at higher doses. In animals that are dosed simultaneously with 5 mmol cysteine/kg body wt, renal uptake of 109 Cd is known to occur in the straight segments of the proximal tubules. At a dose level of less than 1.5 mmol cysteine/kg body wt the present autoradiographical studies show that 109 Cd is taken up predominantly by the proximal convoluted tubules of the kidney cortex. At the critical dose level (1.5 mmol/kg body wt), cysteine decreases the retention of Cd at the s.c. injection site, but probably has little effect on the distribution of Cd between protein and other carrier molecules in the blood. This distribution, however, is altered at higher cysteine dose levels. It is suggested that, under the latter conditions, stable Cd-cysteine complexes are formed in the blood and are filtered readily through the glomeruli. These complexes are taken up in the kidney at the sites of cysteine reabsorption which, by studies with L-[ 35 S]-cysteine, are identified as the straight segments of the proximal tubules. (orig.)

  2. Proximal Tubule Cell Hypothesis for Cardiorenal Syndrome in Diabetes

    Directory of Open Access Journals (Sweden)

    Akihiko Saito

    2011-01-01

    Full Text Available Incidence of cardiovascular disease (CVD is remarkably high among patients with chronic kidney disease (CKD, even in the early microalbuminuric stages with normal glomerular filtration rates. Proximal tubule cells (PTCs mediate metabolism and urinary excretion of vasculotoxic substances via apical and basolateral receptors and transporters. These cells also retrieve vasculoprotective substances from circulation or synthesize them for release into the circulation. PTCs are also involved in the uptake of sodium and phosphate, which are critical for hemodynamic regulation and maintaining the mineral balance, respectively. Dysregulation of PTC functions in CKD is likely to be associated with the development of CVD and is linked to the progression to end-stage renal disease. In particular, PTC dysfunction occurs early in diabetic nephropathy, a leading cause of CKD. It is therefore important to elucidate the mechanisms of PTC dysfunction to develop therapeutic strategies for treating cardiorenal syndrome in diabetes.

  3. Luminal and basolateral uptake of insulin in isolated perfused, proximal tubules

    International Nuclear Information System (INIS)

    Nielsen, S.; Nielsen, J.T.; Christensen, E.I.

    1987-01-01

    The present study was performed to quantitate compare the luminal and the peritubular uptake of 125 I-insulin in isolated, perfused, proximal tubules from rabbit kidneys. 125 I-insulin was added in physiological concentrations to either the perfusate or the bath fluid for 30 min. The luminal uptake in 30 min averaged 0.76 pg/mm at physiological concentrations and 18.0 pg/mm at high insulin concentrations. About 15-41% of the absorbed insulin was digested and 125 I-insulin at physiological and high concentrations in the bath was 0.136 and 0.318 pg, respectively. The data indicates that insulin is bound/absorbed at the basolateral membranes both by a saturable specific mechanism and a nonspecific, nonsaturable mechanism. The basolateral absorption constituted 15.2 and 1.8% of the total tubular extraction of insulin at physiological and high insulin concentrations, respectively. Electron microscope autoradiography showed that, after luminal as well as basolateral endocytosis, insulin was exclusively accumulated in endocytic vacuoles and lysosomes

  4. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule

    DEFF Research Database (Denmark)

    Lee, Justin J; Plain, Allein; Beggs, Megan R

    2017-01-01

    ), active vitamin D 3, and fibroblast growth factor 23 (FGF23). The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms......Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH...... as their regulation of active vitamin D 3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms...

  5. A microfluidic renal proximal tubule with active reabsorptive function.

    Directory of Open Access Journals (Sweden)

    Else M Vedula

    Full Text Available In the kidney, the renal proximal tubule (PT reabsorbs solutes into the peritubular capillaries through active transport. Here, we replicate this reabsorptive function in vitro by engineering a microfluidic PT. The microfluidic PT architecture comprises a porous membrane with user-defined submicron surface topography separating two microchannels representing a PT filtrate lumen and a peritubular capillary lumen. Human PT epithelial cells and microvascular endothelial cells in respective microchannels created a PT-like reabsorptive barrier. Co-culturing epithelial and endothelial cells in the microfluidic architecture enhanced viability, metabolic activity, and compactness of the epithelial layer. The resulting tissue expressed tight junctions, kidney-specific morphology, and polarized expression of kidney markers. The microfluidic PT actively performed sodium-coupled glucose transport, which could be modulated by administration of a sodium-transport inhibiting drug. The microfluidic PT reproduces human physiology at the cellular and tissue levels, and measurable tissue function which can quantify kidney pharmaceutical efficacy and toxicity.

  6. Effects of lead intoxication on intercellular junctions and biochemical alterations of the renal proximal tubule cells.

    Science.gov (United States)

    Navarro-Moreno, L G; Quintanar-Escorza, M A; González, S; Mondragón, R; Cerbón-Solorzáno, J; Valdés, J; Calderón-Salinas, J V

    2009-10-01

    Lead intoxication is a worldwide health problem which frequently affects the kidney. In this work, we studied the effects of chronic lead intoxication (500 ppm of Pb in drinking water during seven months) on the structure, function and biochemical properties of rat proximal tubule cells. Lead-exposed animals showed increased lead concentration in kidney, reduction of calcium and amino acids uptake, oxidative damage and glucosuria, proteinuria, hematuria and reduced urinary pH. These biochemical and physiological alterations were related to striking morphological modifications in the structure of tubule epithelial cells and in the morphology of their mitochondria, nuclei, lysosomes, basal and apical membranes. Interestingly, in addition to the nuclei, inclusion bodies were found in the cytoplasm and in mitochondria. The epithelial cell structure modifications included an early loss of the apical microvillae, followed by a decrement of the luminal space and the respective apposition and proximity of apical membranes, resulting in the formation of atypical intercellular contacts and adhesion structures. Similar but less marked alterations were observed in subacute lead intoxication as well. Our work contributes in the understanding of the physiopathology of lead intoxication on the structure of renal tubular epithelial cell-cell contacts in vivo.

  7. Proximal tubule Na transporter responses are the same during acute and chronic hypertension

    DEFF Research Database (Denmark)

    Magyar, C E; Zhang, Y; Holstein-Rathlou, N H

    2000-01-01

    Acute hypertension in Sprague-Dawley rats (SD) provokes a decrease in renal proximal tubule (PT) salt and fluid reabsorption, redistribution of apical Na/H exchanger isoform 3 (NHE3) and Na-P(i) cotransporter type 2 (NaPi2) out of the brush border into higher density membranes, and inhibition...... to persistent adaptive changes in NHE3 and NaPi2 distribution and/or NKA activity. Renal cortex Na transporter protein density distributions and activities were compared by subcellular fractionation in 1) adult SHR with an acute increase or decrease in arterial pressure and 2) young SD (YSD) and young SHR (YSHR......) vs. adult SD and SHR. In adult hypertensive SHR NHE3 was shifted to membranes of higher densities, analogous to SD with acute hypertension, and there were no further changes with a further increase or decrease in arterial pressure. There was no change in total pool size of NHE3 in cortex in YSHR vs...

  8. Antioxidant Protection against Pathological Mycotoxins Alterations on Proximal Tubules in Rat Kidney

    Directory of Open Access Journals (Sweden)

    Susan Abdu

    2011-04-01

    Full Text Available Background: Ochratoxin A (OTA was one of the mycotoxins and received attention worldwide because of the hazard it posed to human and animal health, where the kidney was the primary target organ for OTA toxicity. In the other hand, dates served as a good source of natural antioxidants and could potentially be considered as a functional food.Methods: The study was performed in the department of biology in King Abdulaziz University. Animals were gavage administrated and divided into four groups: first group received (sodium bicarbonate, second group received (289 µg OTA /kg B.W. /day, third group received (1mg Ajwa/kg B.W. / day and fourth group received (289 µg OTA /kg B.W./day+ 1mg Ajwa /kg B.W. / day. Serum (creatinine - urea levels were measured in each group at the time of tissue collection , some biopsies were fixed in 10% buffered formalin solution for light microscopy processing stained with Haematoxylin and Eosin (H& E., Periodic Acid-Schiff (PAS and Masson´s Trichrome (M.T..Other biopsies were immediately collected into electron microscopy processing. Results: After 28 days, a significant decrease in body weight, kidney weight and relative weight was detected in OTA treated group. Also, Serum (creatinine - urea level were elevated .The normal cyto-architecture of proximal tubules were lost exhibiting damaged bruch border, degenerated, binucleated and karyomegalic cells. The most destructed ultra-structure was the mitochondria which severely swollen with disintegrated membranes. In Ajwa Date extract-group the proximal tubules were normal, whereas in Ajwa date extract + OTA -group the severity of the lesions was significantly reduced. Conclusion: The present results indicated that, Ajwa date have protective effects and ameliorated the lesions of Ochratoxin nepherotoxicity which might lead to kidney failure.

  9. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

    Directory of Open Access Journals (Sweden)

    E.V. Seliverstova

    2015-04-01

    Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

  10. Differential patterns of injury to the proximal tubule of renal cortical slices following in vitro exposure to mercuric chloride, potassium dichromate, or hypoxic conditions.

    Science.gov (United States)

    Ruegg, C E; Gandolfi, A J; Nagle, R B; Brendel, K

    1987-09-15

    The innate susceptibility of renal cell types to these agents was investigated using precision-cut rabbit renal cortical slices made perpendicular to the cortical-papillary axis. Slices were incubated in DME/F12 medium containing 10 microM, 100 microM, or 1 mM concentrations of either metal for 12 hr or in Krebs-Hepes buffer gassed with nitrogen (100%) for 0.75 to 5 hr of hypoxic exposure. To simulate postischemic reperfusion, some slices were transferred to vessels gassed with oxygen after an initial hypoxic period. Mercuric chloride (100 microM) exposure resulted in damage to the straight regions of proximal tubules by 12 hr leaving convoluted regions unaffected. Hypoxia (2.25 hr) and potassium dichromate (100 microM for 12 hr) both caused injury to the convoluted proximal tubules without affecting straight proximal tubular regions. Mercury concentrations of 10 microM and 1 mM had no effect or injured all cell types within the slice, respectively. Similar results were observed for hypoxic periods less than 1.5 hr or greater than 3 hr of exposure. Potassium dichromate had no measurable affect at 10 microM, but at 1 mM focal lesions were observed after 4 hr of exposure, and by 12 hr all cell types within the slice were affected. Intracellular potassium content normalized to DNA correlated well, but always preceded the pathological lesions observed. These results demonstrate that injury to specific regions of the proximal tubule by these agents relates to an innate susceptibility of the intoxicated cell type independent of physiologic feedback or blood delivery patterns proposed as mechanisms of selective injury from in vivo studies.

  11. Proximal Tubules Have the Capacity to Regulate Uptake of Albumin.

    Science.gov (United States)

    Wagner, Mark C; Campos-Bilderback, Silvia B; Chowdhury, Mahboob; Flores, Brittany; Lai, Xianyin; Myslinski, Jered; Pandit, Sweekar; Sandoval, Ruben M; Wean, Sarah E; Wei, Yuan; Satlin, Lisa M; Wiggins, Roger C; Witzmann, Frank A; Molitoris, Bruce A

    2016-02-01

    Evidence from multiple studies supports the concept that both glomerular filtration and proximal tubule (PT) reclamation affect urinary albumin excretion rate. To better understand these roles of glomerular filtration and PT uptake, we investigated these processes in two distinct animal models. In a rat model of acute exogenous albumin overload, we quantified glomerular sieving coefficients (GSC) and PT uptake of Texas Red-labeled rat serum albumin using two-photon intravital microscopy. No change in GSC was observed, but a significant decrease in PT albumin uptake was quantified. In a second model, loss of endogenous albumin was induced in rats by podocyte-specific transgenic expression of diphtheria toxin receptor. In these albumin-deficient rats, exposure to diphtheria toxin induced an increase in albumin GSC and albumin filtration, resulting in increased exposure of the PTs to endogenous albumin. In this case, PT albumin reabsorption was markedly increased. Analysis of known albumin receptors and assessment of cortical protein expression in the albumin overload model, conducted to identify potential proteins and pathways affected by acute protein overload, revealed changes in the expression levels of calreticulin, disabled homolog 2, NRF2, angiopoietin-2, and proteins involved in ATP synthesis. Taken together, these results suggest that a regulated PT cell albumin uptake system can respond rapidly to different physiologic conditions to minimize alterations in serum albumin level. Copyright © 2016 by the American Society of Nephrology.

  12. Endotoxin-induced basal respiration alterations of renal HK-2 cells: A sign of pathologic metabolism down-regulation

    Energy Technology Data Exchange (ETDEWEB)

    Quoilin, C., E-mail: cquoilin@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium); Mouithys-Mickalad, A. [Center of Oxygen Research and Development, Department of Chemistry, University of Liege, 4000 Liege (Belgium); Duranteau, J. [Department of Anaesthesia and Surgical ICU, CHU Bicetre, University Paris XI Sud, 94275 Le Kremlin Bicetre (France); Gallez, B. [Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Universite catholique de Louvain, 1200 Brussels (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer A HK-2 cells model of inflammation-induced acute kidney injury. Black-Right-Pointing-Pointer Two oximetry methods: high resolution respirometry and ESR spectroscopy. Black-Right-Pointing-Pointer Oxygen consumption rates of renal cells decrease when treated with LPS. Black-Right-Pointing-Pointer Cells do not recover normal respiration when the LPS treatment is removed. Black-Right-Pointing-Pointer This basal respiration alteration is a sign of pathologic metabolism down-regulation. -- Abstract: To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal tubular epithelial cells (HK-2) both by high-resolution respirometry and electron spin resonance spectroscopy. These two complementary methods have shown that HK-2 cells exhibit a decreased oxygen consumption rate when treated with LPS. Surprisingly, this cellular respiration alteration persists even after the stress factor was removed. We suggested that this irreversible decrease in renal oxygen consumption after LPS challenge is related to a pathologic metabolic down-regulation such as a lack of oxygen utilization by cells.

  13. Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands

    International Nuclear Information System (INIS)

    Abe, Yugo; Asano, Yusuke; Haba, Naoyuki; Yamada, Toshifumi

    2017-01-01

    We study the discovery potential for the mixing of heavy isospin-singlet neutrinos in extensions of the Tokai-to-Kamioka (T2K) experiment, the Tokai-to-Hyper-Kamiokande (T2HK), the Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector with ≅ 1000 km baseline length and 1 circle off-axis angle, and a plan of adding a small detector at Oki Islands to the T2HK. We further pursue the possibility of measuring the neutrino mass hierarchy and the standard CP-violating phase δ CP in the presence of heavy neutrino mixing by fitting data with the standard oscillation parameters only. We show that the sensitivity to heavy neutrino mixing is highly dependent on δ CP and new CP-violating phases in the heavy neutrino mixing matrix, and deteriorates considerably when these phases conspire to suppress interference between the standard oscillation amplitude and an amplitude arising from heavy neutrino mixing, at the first oscillation peak. Although this suppression is avoided by the use of a beam with smaller off-axis angle, the T2HKK and the T2HK+small Oki detector do not show improvement over the T2HK. As for the mass hierarchy measurement, the wrong mass hierarchy is possibly favored in the T2HK because heavy neutrino mixing can mimic matter effects. In contrast, the T2HKK and the T2HK+small Oki detector are capable of correctly measuring the mass hierarchy despite heavy neutrino mixing, as measurements with different baselines resolve degeneracy between heavy neutrino mixing and matter effects. Notably, adding a small detector at Oki to the T2HK drastically ameliorates the sensitivity, which is the central appeal of this paper. As for the δ CP measurement, there can be a sizable discrepancy between the true δ CP and the value obtained by fitting data with the standard oscillation parameters only, which can be comparable to 1σ resolution of the δ CP measurement. Hence, if a hint of heavy neutrino mixing is discovered, it is necessary to incorporate the effects

  14. Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yugo [Shimane University, Graduate School of Science and Engineering, Matsue (Japan); Miyakonojo College, National Institute of Technology, Miyakonojo-shi Miyazaki (Japan); Asano, Yusuke; Haba, Naoyuki; Yamada, Toshifumi [Shimane University, Graduate School of Science and Engineering, Matsue (Japan)

    2017-12-15

    We study the discovery potential for the mixing of heavy isospin-singlet neutrinos in extensions of the Tokai-to-Kamioka (T2K) experiment, the Tokai-to-Hyper-Kamiokande (T2HK), the Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector with ≅ 1000 km baseline length and 1 {sup circle} off-axis angle, and a plan of adding a small detector at Oki Islands to the T2HK. We further pursue the possibility of measuring the neutrino mass hierarchy and the standard CP-violating phase δ{sub CP} in the presence of heavy neutrino mixing by fitting data with the standard oscillation parameters only. We show that the sensitivity to heavy neutrino mixing is highly dependent on δ{sub CP} and new CP-violating phases in the heavy neutrino mixing matrix, and deteriorates considerably when these phases conspire to suppress interference between the standard oscillation amplitude and an amplitude arising from heavy neutrino mixing, at the first oscillation peak. Although this suppression is avoided by the use of a beam with smaller off-axis angle, the T2HKK and the T2HK+small Oki detector do not show improvement over the T2HK. As for the mass hierarchy measurement, the wrong mass hierarchy is possibly favored in the T2HK because heavy neutrino mixing can mimic matter effects. In contrast, the T2HKK and the T2HK+small Oki detector are capable of correctly measuring the mass hierarchy despite heavy neutrino mixing, as measurements with different baselines resolve degeneracy between heavy neutrino mixing and matter effects. Notably, adding a small detector at Oki to the T2HK drastically ameliorates the sensitivity, which is the central appeal of this paper. As for the δ{sub CP} measurement, there can be a sizable discrepancy between the true δ{sub CP} and the value obtained by fitting data with the standard oscillation parameters only, which can be comparable to 1σ resolution of the δ{sub CP} measurement. Hence, if a hint of heavy neutrino mixing is discovered, it is

  15. Paricalcitol attenuates lipopolysaccharide-induced inflammation and apoptosis in proximal tubular cells through the prostaglandin E₂ receptor EP4

    Directory of Open Access Journals (Sweden)

    Yu Ah Hong

    2017-06-01

    Full Text Available Background: Vitamin D is considered to exert a protective effect on various renal diseases but its underlying molecular mechanism remains poorly understood. This study aimed to determine whether paricalcitol attenuates inflammation and apoptosis during lipopolysaccharide (LPS-induced renal proximal tubular cell injury through the prostaglandin E₂ (PGE₂ receptor EP4. Methods: Human renal tubular epithelial (HK-2 cells were pretreated with paricalcitol (2 ng/mL for 1 hour and exposed to LPS (1 μg/mL. The effects of paricalcitol pretreatment in relation to an EP4 blockade using AH-23848 or EP4 small interfering RNA (siRNA were investigated. Results: The expression of cyclooxygenase-2, PGE₂, and EP4 were significantly increased in LPS-exposed HK-2 cells treated with paricalcitol compared with cells exposed to LPS only. Paricalcitol prevented cell death induced by LPS exposure, and the cotreatment of AH-23848 or EP4 siRNA offset these cell-protective effects. The phosphorylation and nuclear translocation of p65 nuclear factor-kappaB (NF-κB were decreased and the phosphorylation of Akt was increased in LPS-exposed cells with paricalcitol treatment. AH-23848 or EP4 siRNA inhibited the suppressive effects of paricalcitol on p65 NF-κB nuclear translocation and the activation of Akt. The production of proinflammatory cytokines and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells were attenuated by paricalcitol in LPS exposed HK-2 cells. The cotreatment with an EP4 antagonist abolished these anti-inflammatory and antiapoptotic effects. Conclusion: EP4 plays a pivotal role in anti-inflammatory and antiapoptotic effects through Akt and NF-κB signaling after paricalcitol pretreatment in LPS-induced renal proximal tubule cell injury.

  16. Tubule urate and PAH transport: sensitivity and specificity of serum protein inhibition

    International Nuclear Information System (INIS)

    Grantham, J.J.; Kennedy, J.; Cowley, B.

    1987-01-01

    Macromolecules in rabbit serum inhibit the cellular uptake and transepithelial secretion of [ 14 C]urate and p-[ 3 H]aminohippurate ([ 3 H]PAH) in rabbit S 2 proximal tubule segments. To understand better the potential role these inhibitors may have in the regulation of renal organic anion excretion, the authors examined the specificity and relative inhibitory effects on tubule urate and PAH transport of albumin and γ-globulin, the major inhibitory proteins in rabbit serum. Native rabbit serum markedly inhibited the cellular accumulation or urate and PAH by isolated nonperfused segments. Urate and PAH transport was also inhibited by bovine serum, human serum, Cohn-fractionated rabbit albumin, and rabbit γ-globulin, but not by Cohn-fractionated bovine serum albumin. α-Lactalbumin and β-lactoglobulin, derived from milk, also inhibited urate and PAH transport, but to a lesser extent than albumin and γ-globulin. The transport inhibitory effects of proteins were independent of their binding to urate and PAH. Unidirectional influx and the steady-state intracellular accumulation of urate and PAH in suspensions of proximal tubules were decreased by rabbit serum proteins, suggesting that these inhibitors act on the external face of the cells to diminish the uptake of the organic anions. These studies indicate that the principal plasma proteins (albumin and γ-globulin) significantly inhibit urate and PAH transporters in the basolateral membranes of S 2 proximal tubules. They suggest that circulating plasma proteins that can penetrate the basement membrane of proximal tubules may directly modulate the renal excretion of urate and PAH

  17. Secretory NaCl and volume flow in renal tubules.

    Science.gov (United States)

    Beyenbach, K W

    1986-05-01

    This review attempts to give a retrospective survey of the available evidence concerning the secretion of NaCl and fluid in renal tubules of the vertebrate kidney. In the absence of glomerular filtration, epithelial secretory mechanisms, which to this date have not been elucidated, are responsible for the renal excretion of NaCl and water in aglomerular fish. However, proximal tubules isolated from glomerular fish kidneys of the flounder, killifish, and the shark also have the capacity to secrete NaCl and fluid. In shark proximal tubules, fluid secretion appears to be driven via secondary active transport of Cl. In another marine vertebrate, the sea snake, secretion of Na (presumably NaCl) and fluid is observed in freshwater-adapted and water-loaded animals. Proximal tubules of mammals can be made to secrete NaCl in vitro together with secretion of aryl acids. An epithelial cell line derived from dog kidney exhibits secondary active secretion of Cl when stimulated with catecholamines. Tubular secretion of NaCl and fluid may serve a variety of renal functions, all of which are considered here. The occurrence of NaCl and fluid secretion in glomerular proximal tubules of teleosts, elasmobranchs, and reptiles and in mammalian renal tissue cultures suggests that the genetic potential for NaCl secretion is present in every vertebrate kidney.

  18. Effect of alphatocopherol on diameter of proximal convoluted tubules of kidney in diabetic mice

    International Nuclear Information System (INIS)

    Rashid, S.

    2014-01-01

    Objective: To evaluate the effects of alphatocopherol supplement on proximal convoluted tubular diameter of kidney in diabetic mice. Methods: The randomised controlled trials was conducted partly at the National Institute of Health (NIH), Islamabad, and partly in Army Medical College, Rawalpindi, from November 2009 to November 2010. Thirty adult female mice BALB/C were randomly divided into three equal groups. Group A served as the control group. Group B was made diabetic by the intraperitoneal injection of streptozotocin. Group C received injection streptozotocin and was fed with alphatocopherol (vitamin E) supplemented diet. After 12 weeks, the animals were sacrificed and their kidneys were removed for histomorphological study. Results: Diabetes caused significant changes in the diameter of proximal tubule of Experimental Group B (diabetic) compared to the controls in Group A, but these changes were prevented in alphatocopherol treated Group C. Tubular diameter in Group B was significantly reduced compared to the Control Group A (p 0.05). Conclusion: Significant difference in proximal tubular diameter of kidneys between diabetic and alphatocopherol treated diabetic mice confirm that vitamin E does extend a protective role in improving diabetic nephropathy. (author)

  19. Proximal tubule proteins are significantly elevated in bladder urine of patients with ureteropelvic junction obstruction and may represent novel biomarkers: A pilot study.

    Science.gov (United States)

    Gerber, Claire; Harel, Miriam; Lynch, Miranda L; Herbst, Katherine W; Ferrer, Fernando A; Shapiro, Linda H

    2016-04-01

    Ureteropelvic junction obstruction (UPJO) is the major cause of hydronephrosis in children and may lead to renal injury and early renal dysfunction. However, diagnosis of the degree of obstruction and severity of renal injury relies on invasive and often inconclusive renal scans. Biomarkers from voided urine that detect early renal injury are highly desirable because of their noninvasive collection and their potential to assist in earlier and more reliable diagnosis of the severity of obstruction. Early in response to UPJO, increased intrarenal pressure directly impacts the proximal tubule brush border. We hypothesize that single-pass, apically expressed proximal tubule brush border proteins will be shed into the urine early and rapidly and will be reliable noninvasive urinary biomarkers, providing the tools for a more reliable stratification of UPJO patients. We performed a prospective cohort study at Connecticut Children's Medical Center. Bladder urine samples from 12 UPJO patients were obtained prior to surgical intervention. Control urine samples were collected from healthy pediatric patients presenting with primary nocturnal enuresis. We determined levels of NGAL, KIM-1 (previously identified biomarkers), CD10, CD13, and CD26 (potentially novel biomarkers) by ELISA in control and experimental urine samples. Urinary creatinine levels were used to normalize the urinary protein levels measured by ELISA. Each of the proximal tubule proteins outperformed the previously published biomarkers. No differences in urinary NGAL and KIM-1 levels were observed between control and obstructed patients (p = 0.932 and p = 0.799, respectively). However, levels of CD10, CD13, and CD26 were significantly higher in the voided urine of obstructed individuals when compared with controls (p = 0.002, p = 0.024, and p = 0.007, respectively) (Figure). Targeted identification of reliable, noninvasive biomarkers of renal injury is critical to aid in diagnosing patients at risk, guiding

  20. Update on Mechanisms of Renal Tubule Injury Caused by Advanced Glycation End Products

    Directory of Open Access Journals (Sweden)

    Hong Sun

    2016-01-01

    Full Text Available Diabetic nephropathy (DN caused by advanced glycation end products (AGEs may be associated with lipid accumulation in the kidneys. This study was designed to investigate whether Nε-(carboxymethyl lysine (CML, a member of the AGEs family increases lipid accumulation in a human renal tubular epithelial cell line (HK-2 via increasing cholesterol synthesis and uptake and reducing cholesterol efflux through endoplasmic reticulum stress (ERS. Our results showed that CML disrupts cholesterol metabolism in HK-2 cells by activating sterol regulatory element-binding protein 2 (SREBP-2 and liver X receptor (LXR, followed by an increase in 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR mediated cholesterol synthesis and low density lipoprotein receptor (LDLr mediated cholesterol uptake and a reduction in ATP-binding cassette transporter A1 (ABCA1 mediated cholesterol efflux, ultimately causing lipid accumulation in HK-2 cells. All of these responses could be suppressed by an ERS inhibitor, which suggests that CML causes lipid accumulation in renal tubule cells through ERS and that the inhibition of ERS is a potential novel approach to treating CML-induced renal tubular foam cell formation.

  1. Numerical variation of cell lysosomes of the proximal convoluted tubules of mice Kidneys submitted to different X-ray doses

    International Nuclear Information System (INIS)

    Silva Lapa, R. de C.R. da; Pacheco, I.P.; Segreto, C.

    1984-01-01

    The number of cell lysosomes of the proximal convoluted tubules of mice Kidneys (Mus musculus) before and after whole-body irradiation with different X-ray doses is confronted. The mice were sacrificed after 72 hours and the cortex fragments were conduct to electron microscopy. A statistically significant numerical reduction of the lysosomas was observed in 72 hours. (M.A.C.) [pt

  2. Role of diacylglycerol in adrenergic-stimulated sup 86 Rb uptake by proximal tubules

    Energy Technology Data Exchange (ETDEWEB)

    Baines, A.D.; Drangova, R.; Ho, P. (Univ. of Toronto, Ontario (Canada))

    1990-05-01

    We used rat proximal tubule fragments purified by Percoll centrifugation to examine the role of diacylglycerol (DAG) in noradrenergic-stimulated Na+ reabsorption. Tubular DAG concentration and ouabain-inhibitable 86Rb uptake increased within 30 s after adding norepinephrine (NE) and remained elevated for at least 5 min. NE (1 microM) increased DAG content 17% and ouabain-inhibitable 86Rb uptake 23%. Cirazoline-stimulated 86Rb uptake was not inhibited by BaCl, quinidine, or bumetanide (1-10 microM) or by the omission of HCO3- or Cl- from the medium, but it was completely inhibited by ouabain and furosemide. Oleoyl-acetyl glycerol, L-alpha-1,2-dioctanoylglycerol, and L-alpha-1,2-dioleoylglycerol (DOG) increased total 86Rb uptake 8-11%. 12-O-tetradecanoylphorbol-13-acetate (TPA) (5 nM) increased uptake by only 4%. Staurosporine at 5 nM inhibited DOG stimulation completely, whereas 50 nM staurosporine was required to inhibit NE stimulation completely. Sphingosine inhibited DOG stimulation by 66% but did not inhibit NE stimulation. Amiloride (1 mM) completely blocked DOG stimulation. Monensin increased 86Rb uptake 31% and completely blocked the DOG effect but reduced the NE effect by only 26% (P = 0.08). In tubules from salt-loaded rats, NE did not increase DAG concentration, but NE-stimulated 86Rb uptake was reduced by only 23% (P = 0.15). Thus DAG released by NE may stimulate Na+ entry through Na(+)-H+ exchange. NE predominantly stimulates Na(+)-K(+)-adenosinetriphosphatase (ATPase) by activating a protein kinase that is insensitive to DAG and TPA and is inhibited by staurosporine but not by sphingosine. NE may also stimulate K+ efflux through a BaCl-insensitive K+ channel that is inhibited by millimolar furosemide.

  3. Development of a living membrane comprising a functional human renal proximal tubule cell monolayer on polyethersulfone polymeric membrane.

    Science.gov (United States)

    Schophuizen, Carolien M S; De Napoli, Ilaria E; Jansen, Jitske; Teixeira, Sandra; Wilmer, Martijn J; Hoenderop, Joost G J; Van den Heuvel, Lambert P W; Masereeuw, Rosalinde; Stamatialis, Dimitrios

    2015-03-01

    The need for improved renal replacement therapies has stimulated innovative research for the development of a cell-based renal assist device. A key requirement for such a device is the formation of a "living membrane", consisting of a tight kidney cell monolayer with preserved functional organic ion transporters on a suitable artificial membrane surface. In this work, we applied a unique conditionally immortalized proximal tubule epithelial cell (ciPTEC) line with an optimized coating strategy on polyethersulfone (PES) membranes to develop a living membrane with a functional proximal tubule epithelial cell layer. PES membranes were coated with combinations of 3,4-dihydroxy-l-phenylalanine and human collagen IV (Coll IV). The optimal coating time and concentrations were determined to achieve retention of vital blood components while preserving high water transport and optimal ciPTEC adhesion. The ciPTEC monolayers obtained were examined through immunocytochemistry to detect zona occludens 1 tight junction proteins. Reproducible monolayers were formed when using a combination of 2 mg ml(-1) 3,4-dihydroxy-l-phenylalanine (4 min coating, 1h dissolution) and 25 μg ml(-1) Coll IV (4 min coating). The successful transport of (14)C-creatinine through the developed living membrane system was used as an indication for organic cation transporter functionality. The addition of metformin or cimetidine significantly reduced the creatinine transepithelial flux, indicating active creatinine uptake in ciPTECs, most likely mediated by the organic cation transporter, OCT2 (SLC22A2). In conclusion, this study shows the successful development of a living membrane consisting of a reproducible ciPTEC monolayer on PES membranes, an important step towards the development of a bioartificial kidney. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Repair Effect of Seaweed Polysaccharides with Different Contents of Sulfate Group and Molecular Weights on Damaged HK-2 Cells

    Directory of Open Access Journals (Sweden)

    Poonam Bhadja

    2016-05-01

    Full Text Available The structure–activity relationships and repair mechanism of six low-molecular-weight seaweed polysaccharides (SPSs on oxalate-induced damaged human kidney proximal tubular epithelial cells (HK-2 were investigated. These SPSs included Laminaria japonica polysaccharide, degraded Porphyra yezoensis polysaccharide, degraded Gracilaria lemaneiformis polysaccharide, degraded Sargassum fusiforme polysaccharide, Eucheuma gelatinae polysaccharide, and degraded Undaria pinnatifida polysaccharide. These SPSs have a narrow difference of molecular weight (from 1968 to 4020 Da after degradation by controlling H2O2 concentration. The sulfate group (–SO3H content of the six SPSs was 21.7%, 17.9%, 13.3%, 8.2%, 7.0%, and 5.5%, respectively, and the –COOH contents varied between 1.0% to 1.7%. After degradation, no significant difference was observed in the contents of characteristic –SO3H and –COOH groups of polysaccharides. The repair effect of polysaccharides was determined using cell-viability test by CCK-8 assay and cell-morphology test by hematoxylin-eosin staining. The results revealed that these SPSs within 0.1–100 μg/mL did not express cytotoxicity in HK-2 cells, and each polysaccharide had a repair effect on oxalate-induced damaged HK-2 cells. Simultaneously, the content of polysaccharide –SO3H was positively correlated with repair ability. Furthermore, the low-molecular-weight degraded polysaccharides showed better repair activity on damaged HK-2 cells than their undegraded counterpart. Our results can provide reference for inhibiting the formation of kidney stones and for developing original anti-stone polysaccharide drugs.

  5. Pathophyisiology analysis overload nephron protein in the proximal tubule damage in the nephrolithiasis size stones of 0.6-1.0 sm

    Directory of Open Access Journals (Sweden)

    Yu. Ye. Rohovyi

    2017-07-01

    Full Text Available Nephrolithiasis as the most common urological disorder characterized by frequent early relapses, acquires a social character, because these patients are 30 to 45% of all urological patients, while in Europe the disease is diagnosed in 2% of the population. The study included 40 patients with nephrolithiasis, 10 patients constituted the control group. Set the “hidden” damage to the proximal nephron in the presence of renal stones with a size of 0.6-1.0 cm in the upper third of the ureter, the upper and middle sections of the calyx, which is confirmed by the inhibition of enzymatic fibrinolytic activity of urine, the presence of tubular proteinuria in the absence of inhibition of proximal reabsorption of sodium ions. The link “hidden” damage to the proximal tubule of the degree of overload of the proximal nephron is a protein graphics multicorrelation dependence between the protein concentration of urine, standardized excretion protein and excretion, which are becoming more significant disharmony form towards control in the following sequence: the upper third of the ureter, medium cup, top cup.

  6. Transport and activation of S-(1,2-dichlorovinyl)-L-cysteine and N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine in rat kidney proximal tubules

    International Nuclear Information System (INIS)

    Zhang, G.H.; Stevens, J.L.

    1989-01-01

    An important step in understanding the mechanism underlying the tubular specificity of the nephrotoxicity of toxic cysteine conjugates is to identify the rate-limiting steps in their activation. The rate-limiting steps in the activation of toxic cysteine conjugates were characterized using isolated proximal tubules from the rat and 35S-labeled S-(1,2-dichlorovinyl)-L-cysteine (DCVC) and N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NAC-DCVC) as model compounds. The accumulation by tubules of 35S radiolabel from both DCVC and NAC-DCVC was time and temperature dependent and was mediated by both Na+-dependent and independent processes. Kinetic studies with DCVC in the presence of sodium revealed the presence of two components with apparent Km and Vmax values of (1) 46 microM and 0.21 nmol/mg min and (2) 2080 microM and 7.3 nmol/mg.min. NAC-DVVC uptake was via a single system with apparent Km and Vmax values of 157 microM and 0.65 nmol/mg.min, respectively. Probenecid, an inhibitor of the renal organic anion transport system, inhibited accumulation of radiolabel from NAC-DCVC, but not from DCVC. The covalent binding of 35S label to cellular macromolecules was much greater from [35S]DCVC than from NAC-[35S]DCVC. Analysis of metabolites showed that a substantial amount of the cellular NAC-[35S]DCVC was unmetabolized while [35S]DCVC was rapidly metabolized to bound 35S-labeled material and unidentified products. The data suggest that DCVC is rapidly metabolized following transport, but that activation of NAC-DCVC depends on a slower rate of deacetylation. The results are discussed with regard to the segment specificity of cysteine conjugate toxicity and the role of disposition in vivo in the nephrotoxicity of glutathione conjugates

  7. Human kidney proximal tubule cells are vulnerable to the effects of Rauwolfia serpentina.

    Science.gov (United States)

    Mossoba, Miriam E; Flynn, Thomas J; Vohra, Sanah; Wiesenfeld, Paddy L; Sprando, Robert L

    2015-12-01

    Rauwolfia serpentina (or Snake root plant) is a botanical dietary supplement marketed in the USA for maintaining blood pressure. Very few studies have addressed the safety of this herb, despite its wide availability to consumers. Its reported pleiotropic effects underscore the necessity for evaluating its safety. We used a human kidney cell line to investigate the possible negative effects of R. serpentina on the renal system in vitro, with a specific focus on the renal proximal tubules. We evaluated cellular and mitochondrial toxicity, along with a variety of other kidney-specific toxicology biomarkers. We found that R. serpentina was capable of producing highly detrimental effects in our in vitro renal cell system. These results suggest more studies are needed to investigate the safety of this dietary supplement in both kidney and other target organ systems.

  8. Experimental type II diabetes and related models of impaired glucose metabolism differentially regulate glucose transporters at the proximal tubule brush border membrane.

    Science.gov (United States)

    Chichger, Havovi; Cleasby, Mark E; Srai, Surjit K; Unwin, Robert J; Debnam, Edward S; Marks, Joanne

    2016-06-01

    What is the central question of this study? Although SGLT2 inhibitors represent a promising treatment for patients suffering from diabetic nephropathy, the influence of metabolic disruption on the expression and function of glucose transporters is largely unknown. What is the main finding and its importance? In vivo models of metabolic disruption (Goto-Kakizaki type II diabetic rat and junk-food diet) demonstrate increased expression of SGLT1, SGLT2 and GLUT2 in the proximal tubule brush border. In the type II diabetic model, this is accompanied by increased SGLT- and GLUT-mediated glucose uptake. A fasted model of metabolic disruption (high-fat diet) demonstrated increased GLUT2 expression only. The differential alterations of glucose transporters in response to varying metabolic stress offer insight into the therapeutic value of inhibitors. SGLT2 inhibitors are now in clinical use to reduce hyperglycaemia in type II diabetes. However, renal glucose reabsorption across the brush border membrane (BBM) is not completely understood in diabetes. Increased consumption of a Western diet is strongly linked to type II diabetes. This study aimed to investigate the adaptations that occur in renal glucose transporters in response to experimental models of diet-induced insulin resistance. The study used Goto-Kakizaki type II diabetic rats and normal rats rendered insulin resistant using junk-food or high-fat diets. Levels of protein kinase C-βI (PKC-βI), GLUT2, SGLT1 and SGLT2 were determined by Western blotting of purified renal BBM. GLUT- and SGLT-mediated d-[(3) H]glucose uptake by BBM vesicles was measured in the presence and absence of the SGLT inhibitor phlorizin. GLUT- and SGLT-mediated glucose transport was elevated in type II diabetic rats, accompanied by increased expression of GLUT2, its upstream regulator PKC-βI and SGLT1 protein. Junk-food and high-fat diet feeding also caused higher membrane expression of GLUT2 and its upstream regulator PKC

  9. Effect of HK2, PKM2 and LDHA on Cetuximab efficacy in metastatic colorectal cancer.

    Science.gov (United States)

    Wang, Haohua; Peng, Roujun; Chen, Xiuxing; Jia, Rui; Huang, Chunyue; Huang, Yuanyuan; Xia, Liangping; Guo, Guifang

    2018-04-01

    Although hexokinase (HK) 2, pyruvate kinase muscle (PKM) isozyme 2 and lactate dehydrogenase (LDH) A predict the efficacy of medicines in various solid tumors, their ability to predict the efficacy of cetuximab in metastatic colorectal cancer (mCRC) remains unclear. mCRC patients with pathological specimens who received cetuximab and chemotherapy from 2005 to 2015 in the present institution were enrolled. Immunohistochemistry was used to detect HK2, PKM2 and LDHA expression. SPSS20 was used for statistical analysis. A total of 68 patients were included; 33 received cetuximab plus chemotherapy as first-line therapy, and the rest, as second- or later-line therapy. HK2 expression levels were increased in cancer compared with normal tissue (75.4% vs. 40%; P<0.001), however PKM2 (P=0.243) and LDHA (P=0.067) expression levels were not. For progression-free survival (PFS) with first-line cetuximab plus chemotherapy, patients with high HK2 expression exhibited longer PFS compared with those with low HK2 expression (23.9 months vs. 6.9 months; P=0.021). However, this positive association was absent in 35 cases administered first-line chemotherapy alone (13.4 months vs. 13.5 months; P=0.539). LDHA expression was associated with the PFS of patients receiving first-line chemotherapy (18.3 and 10.1 months for high and low expression, respectively; P=0.005), whereas this association was absent in cetuximab plus chemotherapy cases (19.9 months vs. 12 months; P=0.522). Furthermore, high LDHA expression correlated with high overall response rate (ORR) (72.2% vs. 15.4%, P=0.006) for chemotherapy, however not disease control rate (DCR) (P=0.074). Neither DCR nor ORR were associated with HK2 expression. PKM2 expression did not affect PFS, DCR or ORR. LDHA expression (P=0.005), pathological differentiation (P=0.019) and synchronous/metachronous metastasis (P=0.014) were independent predictive factors of PFS for all first-line patients, and tumor differentiation (P=0.002) was associated

  10. Paracellular transport and energy utilization in the renal tubule.

    Science.gov (United States)

    Yu, Alan S L

    2017-09-01

    Paracellular transport across the tight junction is a general mechanism for transepithelial transport of solutes in epithelia, including the renal tubule. However, why paracellular transport evolved, given the existence of a highly versatile system for transcellular transport, is unknown. Recent studies have identified the paracellular channel, claudin-2, that is responsible for paracellular reabsorption of sodium in the proximal renal tubule. Knockout of claudin-2 in mice impairs proximal sodium and fluid reabsorption but is compensated by upregulation of sodium reabsorption in the loop of Henle. This occurs at the expense of increased renal oxygen consumption, hypoxia of the outer medulla and increased susceptibility to ischemic kidney injury. Paracellular transport can be viewed as a mechanism to exploit the potential energy in existing electrochemical gradients to drive passive transepithelial transport without consuming additional energy. In this way, it enhances the efficiency of energy utilization by transporting epithelia.

  11. Stimulation of Na+-alanine cotransport activates a voltage-dependent conductance in single proximal tubule cells isolated from frog kidney

    Science.gov (United States)

    Robson, L; Hunter, M

    1999-01-01

    The swelling induced by Na+-alanine cotransport in proximal tubule cells of the frog kidney is followed by regulatory volume decrease (RVD). This RVD is inhibited by gadolinium (Gd3+), an inhibitor of stretch-activated channels, but is independent of extracellular Ca2+. In this study, the whole cell patch clamp technique was utilized to examine the effect of Na+-alanine cotransport on two previously identified volume- and Gd3+-sensitive conductances. One conductance is voltage dependent and anion selective (GVD) whilst the other is voltage independent and cation selective (GVI). Addition of 5 mM L-alanine to the bathing solution increased the whole cell conductance and gave a positive (depolarizing) shift in the reversal potential (Vrev, equivalent to the membrane potential in current-clamped cells) consistent with activation of Na+-alanine cotransport. Vrev shifted from -36 ± 4·9 to +12·9 ± 4·2 mV (n= 15). In the presence of alanine, the total whole cell conductance had several components including the cotransporter conductance and GVD and GVI. These conductances were separated using Gd3+, which inhibits both GVD and GVI, and the time dependency of GVD. Of these two volume-sensitive conductances, L-alanine elicited a specific increase in GVD, whereas GVI was unaffected. The L-alanine-induced activation of GVD was significantly reduced when cells were incubated in a hypertonic bathing solution. In summary, in single proximal tubule cells isolated from frog kidney, on stimulation of Na+-alanine cotransport GVD is activated, while GVI is unaffected. Taken with other evidence, this suggests that GVD is activated by cell swelling, consequent upon alanine entry, and may play a role as an anion efflux pathway during alanine-induced volume regulation. PMID:10226159

  12. Macrophage-stimulating protein attenuates gentamicin-induced inflammation and apoptosis in human renal proximal tubular epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ko Eun [Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of); Kim, Eun Young [Department of Physiology, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of); Kim, Chang Seong; Choi, Joon Seok; Bae, Eun Hui; Ma, Seong Kwon [Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of); Kim, Kyung Keun [Department of Pharmacology, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of); Lee, Jong Un [Department of Physiology, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of); Kim, Soo Wan, E-mail: skimw@chonnam.ac.kr [Department of Internal Medicine, Chonnam National University Medical School, Gwangju 501-757 (Korea, Republic of)

    2013-05-10

    Highlights: •MSP/RON system is activated in rat kidney damaged by gentamicin. •MSP inhibits GM-induced cellular apoptosis and inflammation in HK-2 cells. •MSP attenuates GM-induced activation of MAPKs and NF-κB pathways in HK-2 cells. -- Abstract: The present study aimed to investigate whether macrophage-stimulating protein (MSP) treatment attenuates renal apoptosis and inflammation in gentamicin (GM)-induced tubule injury and its underlying molecular mechanisms. To examine changes in MSP and its receptor, recepteur d’origine nantais (RON) in GM-induced nephropathy, rats were injected with GM for 7 days. Human renal proximal tubular epithelial (HK-2) cells were incubated with GM for 24 h in the presence of different concentrations of MSP and cell viability was measured by MTT assay. Apoptosis was determined by flow cytometry of cells stained with fluorescein isothiocyanate-conjugated annexin V protein and propidium iodide. Expression of Bcl-2, Bax, caspase-3, cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB), IκB-α, and mitogen-activated protein kinases (MAPKs) was analyzed by semiquantitative immunoblotting. MSP and RON expression was significantly greater in GM-treated rats, than in untreated controls. GM-treatment reduced HK-2 cell viability, an effect that was counteracted by MSP. Flow cytometry and DAPI staining revealed GM-induced apoptosis was prevented by MSP. GM reduced expression of anti-apoptotic protein Bcl-2 and induced expression of Bax and cleaved caspase 3; these effects and GM-induced expression of COX-2 and iNOS were also attenuated by MSP. GM caused MSP-reversible induction of phospho-ERK, phospho-JNK, and phospho-p38. GM induced NF-κB activation and degradation of IκB-α; the increase in nuclear NF-κB was blocked by inhibitors of ERK, JNK, p-38, or MSP pretreatment. These findings suggest that MSP attenuates GM-induced inflammation and apoptosis by inhibition of the MAPKs

  13. Organic anion and cation SLC22 "drug" transporter (Oat1, Oat3, and Oct1 regulation during development and maturation of the kidney proximal tubule.

    Directory of Open Access Journals (Sweden)

    Thomas F Gallegos

    Full Text Available Proper physiological function in the pre- and post-natal proximal tubule of the kidney depends upon the acquisition of selective permeability, apical-basolateral epithelial polarity and the expression of key transporters, including those involved in metabolite, toxin and drug handling. Particularly important are the SLC22 family of transporters, including the organic anion transporters Oat1 (originally identified as NKT and Oat3 as well as the organic cation transporter Oct1. In ex vivo cultures of metanephric mesenchyme (MM; the embryonic progenitor tissue of the nephron Oat function was evident before completion of nephron segmentation and corresponded with the maturation of tight junctions as measured biochemically by detergent extractability of the tight junction protein, ZO-1. Examination of available time series microarray data sets in the context of development and differentiation of the proximal tubule (derived from both in vivo and in vitro/ex vivo developing nephrons allowed for correlation of gene expression data to biochemically and functionally defined states of development. This bioinformatic analysis yielded a network of genes with connectivity biased toward Hnf4α (but including Hnf1α, hyaluronic acid-CD44, and notch pathways. Intriguingly, the Oat1 and Oat3 genes were found to have strong temporal co-expression with Hnf4α in the cultured MM supporting the notion of some connection between the transporters and this transcription factor. Taken together with the ChIP-qPCR finding that Hnf4α occupies Oat1, Oat3, and Oct1 proximal promoters in the in vivo differentiating rat kidney, the data suggest a network of genes with Hnf4α at its center plays a role in regulating the terminal differentiation and capacity for drug and toxin handling by the nascent proximal tubule of the kidney.

  14. HK2 Recruitment to Phospho-BAD Prevents Its Degradation, Promoting Warburg Glycolysis by Theileria-Transformed Leukocytes.

    Science.gov (United States)

    Haidar, Malak; Lombès, Anne; Bouillaud, Frédéric; Kennedy, Eileen J; Langsley, Gordon

    2017-03-10

    Theileria annulata infects bovine leukocytes, transforming them into invasive, cancer-like cells that cause the widespread disease called tropical theileriosis. We report that in Theileria-transformed leukocytes hexokinase-2 (HK2) binds to B cell lymphoma-2-associated death promoter (BAD) only when serine (S) 155 in BAD is phosphorylated. We show that HK2 recruitment to BAD is abolished by a cell-penetrating peptide that acts as a nonphosphorylatable BAD substrate that inhibits endogenous S155 phosphorylation, leading to complex dissociation and ubiquitination and degradation of HK2 by the proteasome. As HK2 is a critical enzyme involved in Warburg glycolysis, its loss forces Theileria-transformed macrophages to switch back to HK1-dependent oxidative glycolysis that down-regulates macrophage proliferation only when they are growing on glucose. When growing on galactose, degradation of HK2 has no effect on Theileria-infected leukocyte proliferation, because metabolism of this sugar is independent of hexokinases. Thus, targeted disruption of the phosphorylation-dependent HK2/BAD complex may represent a novel approach to control Theileria-transformed leukocyte proliferation.

  15. Hypoxia inducible factor 1-alpha (HIF-1 alpha is induced during reperfusion after renal ischemia and is critical for proximal tubule cell survival.

    Directory of Open Access Journals (Sweden)

    Elisa Conde

    Full Text Available Acute tubular necrosis (ATN caused by ischemia/reperfusion (I/R during renal transplantation delays allograft function. Identification of factors that mediate protection and/or epithelium recovery could help to improve graft outcome. We studied the expression, regulation and role of hypoxia inducible factor 1-alpha (HIF-1 α, using in vitro and in vivo experimental models of I/R as well as human post-transplant renal biopsies. We found that HIF-1 α is stabilized in proximal tubule cells during ischemia and unexpectedly in late reperfusion, when oxygen tension is normal. Both inductions lead to gene expression in vitro and in vivo. In vitro interference of HIF-1 α promoted cell death and in vivo interference exacerbated tissue damage and renal dysfunction. In pos-transplant human biopsies, HIF-1 α was expressed only in proximal tubules which exhibited normal renal structure with a significant negative correlation with ATN grade. In summary, using experimental models and human biopsies, we identified a novel HIF-1 α induction during reperfusion with a potential critical role in renal transplant.

  16. Effects of mercury on lysosomal protein digestion in the kidney proximal tubule

    International Nuclear Information System (INIS)

    Madsen, K.M.; Christensen, E.I.

    1978-01-01

    The effect of mercury on renal lysosomal protein digestion was studied after administration of mercury in vitro and in vivo. Mercuric chloride or methylmercury chloride was added in vitro to lysosomal enzymes isolated from normal rats, and subsequently, digestion experiments were carried out using 125 I-labeled lysozyme or cytochrome c as substrate proteins. Both mercury compounds produced a concentration-dependent inhibition of the degradation of the proteins, mercuric chloride being the strongest inhibitor. Mercuric chloride was also administered to rats in vivo for 5 to 8 months. Renal lysosomal enzymes from these animals also had a decreased ability to digest the two substrate proteins. Furthermore, the digestion of lysozyme intravenously injected into mercury-intoxicated rats was decreased in renal cortical slices incubated in vitro. Electron microscope autoradiography showed that intravenously injected labeled lysozyme was located primarily over lysosomes in proximal tubule cells 1 hour after injection in both control animals and mercury-intoxicated rats. These results suggest a decreased catabolism of low molecular weight proteins in the kidney during chronic mercury intoxication

  17. Antenatal glucocorticoid treatment alters Na+ uptake in renal proximal tubule cells from adult offspring in a sex-specific manner

    OpenAIRE

    Su, Yixin; Bi, Jianli; Pulgar, Victor M.; Figueroa, Jorge; Chappell, Mark; Rose, James C.

    2015-01-01

    We have shown a sex-specific effect of fetal programming on Na+ excretion in adult sheep. The site of this effect in the kidney is unknown. Therefore, we tested the hypothesis that renal proximal tubule cells (RPTCs) from adult male sheep exposed to betamethasone (Beta) before birth have greater Na+ uptake than do RPTCs from vehicle-exposed male sheep and that RPTCs from female sheep similarly exposed are not influenced by antenatal Beta. In isolated RPTCs from 1- to 1.5-yr-old male and femal...

  18. Effects of advanced glycation end products on ezrin-dependent functions in LLC-PK1 proximal tubule cells.

    Science.gov (United States)

    Bach, Leon A; Gallicchio, Marisa A; McRobert, E Anne; Tikoo, Anjali; Cooper, Mark E

    2005-06-01

    We have recently shown that advanced glycation products (AGEs) bind to the ERM (ezrin, radixin, moesin) family of proteins. ERM proteins act as cross-linkers between cell membrane proteins and the actin cytoskeleton. They are also involved in signal transduction pathways. They therefore have a critical role in normal cell processes, including modulation of cell shape, adhesion, and motility. We postulate that AGEs may contribute to diabetic complications by disrupting ERM function. In support of this hypothesis, AGEs inhibit ezrin-dependent tubulogenesis of proximal tubule cells. Phosphorylation is an important activating mechanism for ERM proteins, and AGEs inhibit ezrin phosphorylation mediated by the epidermal growth factor receptor.

  19. Effect of acute acid-base disturbances on ErbB1/2 tyrosine phosphorylation in rabbit renal proximal tubules.

    Science.gov (United States)

    Skelton, Lara A; Boron, Walter F

    2013-12-15

    The renal proximal tubule (PT) is a major site for maintaining whole body pH homeostasis and is responsible for reabsorbing ∼80% of filtered HCO3(-), the major plasma buffer, into the blood. The PT adapts its rate of HCO3(-) reabsorption (JHCO3(-)) in response to acute acid-base disturbances. Our laboratory previously showed that single isolated perfused PTs adapt JHCO3(-) in response to isolated changes in basolateral (i.e., blood side) CO2 and HCO3(-) concentrations but, surprisingly, not to pH. The response to CO2 concentration can be blocked by the ErbB family tyrosine kinase inhibitor PD-168393. In the present study, we exposed enriched rabbit PT suspensions to five acute acid-base disturbances for 5 and 20 min using a panel of phosphotyrosine (pY)-specific antibodies to determine the influence of each disturbance on pan-pY, ErbB1-specific pY (four sites), and ErbB2-specific pY (two sites). We found that each acid-base treatment generated a distinct temporal pY pattern. For example, the summated responses of the individual ErbB1/2-pY sites to each disturbance showed that metabolic acidosis (normal CO2 concentration and reduced HCO3(-) concentration) produced a transient summated pY decrease (5 vs. 20 min), whereas metabolic alkalosis produced a transient increase. Respiratory acidosis (normal HCO3(-) concentration and elevated CO2 concentration) had little effect on summated pY at 5 min but produced an elevation at 20 min, whereas respiratory alkalosis produced a reduction at 20 min. Our data show that ErbB1 and ErbB2 in the PT respond to acute acid-base disturbances, consistent with the hypothesis that they are part of the signaling cascade.

  20. Proximal tubule-specific glutamine synthetase deletion alters basal and acidosis-stimulated ammonia metabolism

    Science.gov (United States)

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E.; Lamers, Wouter H.; Chaudhry, Farrukh A.; Verlander, Jill W.

    2016-01-01

    Glutamine synthetase (GS) catalyzes the recycling of NH4+ with glutamate to form glutamine. GS is highly expressed in the renal proximal tubule (PT), suggesting ammonia recycling via GS could decrease net ammoniagenesis and thereby limit ammonia available for net acid excretion. The purpose of the present study was to determine the role of PT GS in ammonia metabolism under basal conditions and during metabolic acidosis. We generated mice with PT-specific GS deletion (PT-GS-KO) using Cre-loxP techniques. Under basal conditions, PT-GS-KO increased urinary ammonia excretion significantly. Increased ammonia excretion occurred despite decreased expression of key proteins involved in renal ammonia generation. After the induction of metabolic acidosis, the ability to increase ammonia excretion was impaired significantly by PT-GS-KO. The blunted increase in ammonia excretion occurred despite greater expression of multiple components of ammonia generation, including SN1 (Slc38a3), phosphate-dependent glutaminase, phosphoenolpyruvate carboxykinase, and Na+-coupled electrogenic bicarbonate cotransporter. We conclude that 1) GS-mediated ammonia recycling in the PT contributes to both basal and acidosis-stimulated ammonia metabolism and 2) adaptive changes in other proteins involved in ammonia metabolism occur in response to PT-GS-KO and cause an underestimation of the role of PT GS expression. PMID:27009341

  1. Ouabain Protects Human Renal Cells against the Cytotoxic Effects of Shiga Toxin Type 2 and Subtilase Cytotoxin

    Directory of Open Access Journals (Sweden)

    María M. Amaral

    2017-07-01

    Full Text Available Hemolytic uremic syndrome (HUS is one of the most common causes of acute renal failure in children. The majority of cases are associated with Shiga toxin (Stx-producing Escherichia coli (STEC. In Argentina, HUS is endemic and presents the highest incidence rate in the world. STEC strains expressing Stx type 2 (Stx2 are responsible for the most severe cases of this pathology. Subtilase cytotoxin (SubAB is another STEC virulence factor that may contribute to HUS pathogenesis. To date, neither a licensed vaccine nor effective therapy for HUS is available for humans. Considering that Ouabain (OUA may prevent the apoptosis process, in this study we evaluated if OUA is able to avoid the damage caused by Stx2 and SubAB on human glomerular endothelial cells (HGEC and the human proximal tubule epithelial cell (HK-2 line. HGEC and HK-2 were pretreated with OUA and then incubated with the toxins. OUA protected the HGEC viability from Stx2 and SubAB cytotoxic effects, and also prevented the HK-2 viability from Stx2 effects. The protective action of OUA on HGEC and HK-2 was associated with a decrease in apoptosis and an increase in cell proliferation. Our data provide evidence that OUA could be considered as a therapeutic strategy to avoid the renal damage that precedes HUS.

  2. A pharmacologically-based array to identify targets of cyclosporine A-induced toxicity in cultured renal proximal tubule cells

    International Nuclear Information System (INIS)

    Sarró, Eduard; Jacobs-Cachá, Conxita; Itarte, Emilio; Meseguer, Anna

    2012-01-01

    Mechanisms of cyclosporine A (CsA)-induced nephrotoxicity were generally thought to be hemodynamic in origin; however, there is now accumulating evidence of a direct tubular effect. Although genomic and proteomic experiments by our group and others provided overall information on genes and proteins up- or down-regulated by CsA in proximal tubule cells (PTC), a comprehensive view of events occurring after CsA exposure remains to be described. For this purpose, we applied a pharmacologic approach based on the use of known activities of a large panel of potentially protective compounds and evaluated their efficacy in preventing CsA toxicity in cultured mouse PTC. Our results show that compounds that blocked protein synthesis and apoptosis, together with the CK2 inhibitor DMAT and the PI3K inhibitor apigenin, were the most efficient in preventing CsA toxicity. We also identified GSK3, MMPs and PKC pathways as potential targets to prevent CsA damage. Additionally, heparinase-I and MAPK inhibitors afforded partial but significant protection. Interestingly, antioxidants and calcium metabolism-related compounds were unable to ameliorate CsA-induced cytotoxicity. Subsequent experiments allowed us to clarify the hierarchical relationship of targeted pathways after CsA treatment, with ER stress identified as an early effector of CsA toxicity, which leads to ROS generation, phenotypical changes and cell death. In summary, this work presents a novel experimental approach to characterizing cellular responses to cytotoxics while pointing to new targets to prevent CsA-induced toxicity in proximal tubule cells. Highlights: ► We used a novel pharmacological approach to elucidate cyclosporine (CsA) toxicity. ► The ability of a broad range of compounds to prevent CsA toxicity was evaluated. ► CsA toxicity was monitored using LDH release assay and PARP cleavage. ► Protein synthesis, PI3K, GSK3, MMP, PKC and caspase inhibitors prevented CsA toxicity. ► We also identified ER

  3. A pharmacologically-based array to identify targets of cyclosporine A-induced toxicity in cultured renal proximal tubule cells

    Energy Technology Data Exchange (ETDEWEB)

    Sarró, Eduard, E-mail: eduard.sarro@vhir.org [Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Renal Physiopathology, CIBBIM-Nanomedicine, Vall d' Hebron Research Institute (VHIR), 08035 Barcelona (Spain); Jacobs-Cachá, Conxita, E-mail: conxita.jacobs@vhir.org [Renal Physiopathology, CIBBIM-Nanomedicine, Vall d' Hebron Research Institute (VHIR), 08035 Barcelona (Spain); Itarte, Emilio, E-mail: emili.itarte@uab.es [Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Meseguer, Anna, E-mail: ana.meseguer@vhir.org [Renal Physiopathology, CIBBIM-Nanomedicine, Vall d' Hebron Research Institute (VHIR), 08035 Barcelona (Spain); Departament de Bioquimica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain)

    2012-01-15

    Mechanisms of cyclosporine A (CsA)-induced nephrotoxicity were generally thought to be hemodynamic in origin; however, there is now accumulating evidence of a direct tubular effect. Although genomic and proteomic experiments by our group and others provided overall information on genes and proteins up- or down-regulated by CsA in proximal tubule cells (PTC), a comprehensive view of events occurring after CsA exposure remains to be described. For this purpose, we applied a pharmacologic approach based on the use of known activities of a large panel of potentially protective compounds and evaluated their efficacy in preventing CsA toxicity in cultured mouse PTC. Our results show that compounds that blocked protein synthesis and apoptosis, together with the CK2 inhibitor DMAT and the PI3K inhibitor apigenin, were the most efficient in preventing CsA toxicity. We also identified GSK3, MMPs and PKC pathways as potential targets to prevent CsA damage. Additionally, heparinase-I and MAPK inhibitors afforded partial but significant protection. Interestingly, antioxidants and calcium metabolism-related compounds were unable to ameliorate CsA-induced cytotoxicity. Subsequent experiments allowed us to clarify the hierarchical relationship of targeted pathways after CsA treatment, with ER stress identified as an early effector of CsA toxicity, which leads to ROS generation, phenotypical changes and cell death. In summary, this work presents a novel experimental approach to characterizing cellular responses to cytotoxics while pointing to new targets to prevent CsA-induced toxicity in proximal tubule cells. Highlights: ► We used a novel pharmacological approach to elucidate cyclosporine (CsA) toxicity. ► The ability of a broad range of compounds to prevent CsA toxicity was evaluated. ► CsA toxicity was monitored using LDH release assay and PARP cleavage. ► Protein synthesis, PI3K, GSK3, MMP, PKC and caspase inhibitors prevented CsA toxicity. ► We also identified ER

  4. Interactive toxicity of inorganic mercury and trichloroethylene in rat and human proximal tubules: Effects on apoptosis, necrosis, and glutathione status

    International Nuclear Information System (INIS)

    Lash, Lawrence H.; Putt, David A.; Hueni, Sarah E.; Payton, Scott G.; Zwickl, Joshua

    2007-01-01

    Simultaneous or prior exposure to one chemical may alter the concurrent or subsequent response to another chemical, often in unexpected ways. This is particularly true when the two chemicals share common mechanisms of action. The present study uses the paradigm of prior exposure to study the interactive toxicity between inorganic mercury (Hg 2+ ) and trichloroethylene (TRI) or its metabolite S-(1,2-dichlorovinyl)-L-cysteine (DCVC) in rat and human proximal tubule. Pretreatment of rats with a subtoxic dose of Hg 2+ increased expression of glutathione S-transferase-α1 (GSTα1) but decreased expression of GSTα2, increased activities of several GSH-dependent enzymes, and increased GSH conjugation of TRI. Primary cultures of rat proximal tubular (rPT) cells exhibited both necrosis and apoptosis after incubation with Hg 2+ . Pretreatment of human proximal tubular (hPT) cells with Hg 2+ caused little or no changes in GST expression or activities of GSH-dependent enzymes, decreased apoptosis induced by TRI or DCVC, but increased necrosis induced by DCVC. In contrast, pretreatment of hPT cells with TRI or DCVC protected from Hg 2+ by decreasing necrosis and increasing apoptosis. Thus, whereas pretreatment of hPT cells with Hg 2+ exacerbated cellular injury due to TRI or DCVC by shifting the response from apoptosis to necrosis, pretreatment of hPT cells with either TRI or DCVC protected from Hg 2+ -induced cytotoxicity by shifting the response from necrosis to apoptosis. These results demonstrate that by altering processes related to GSH status, susceptibilities of rPT and hPT cells to acute injury from Hg 2+ , TRI, or DCVC are markedly altered by prior exposures

  5. Detailed investigations of proximal tubular function in Imerslund-Grasbeck syndrome

    DEFF Research Database (Denmark)

    Storm, Tina; Zeitz, Christina; Cases, Olivier

    2013-01-01

    expressed in the small intestine as well as the proximal tubules of the kidney and exhibit an interdependent relationship for post-translational processing and trafficking. In the proximal tubules cubilin is involved in the reabsorption of several filtered plasma proteins including vitamin carriers...

  6. Coordination and redox state-dependent structural changes of the heme-based oxygen sensor AfGcHK associated with intraprotein signal transduction.

    Science.gov (United States)

    Stranava, Martin; Man, Petr; Skálová, Tereza; Kolenko, Petr; Blaha, Jan; Fojtikova, Veronika; Martínek, Václav; Dohnálek, Jan; Lengalova, Alzbeta; Rosůlek, Michal; Shimizu, Toru; Martínková, Markéta

    2017-12-22

    The heme-based oxygen sensor histidine kinase Af GcHK is part of a two-component signal transduction system in bacteria. O 2 binding to the Fe(II) heme complex of its N-terminal globin domain strongly stimulates autophosphorylation at His 183 in its C-terminal kinase domain. The 6-coordinate heme Fe(III)-OH - and -CN - complexes of Af GcHK are also active, but the 5-coordinate heme Fe(II) complex and the heme-free apo-form are inactive. Here, we determined the crystal structures of the isolated dimeric globin domains of the active Fe(III)-CN - and inactive 5-coordinate Fe(II) forms, revealing striking structural differences on the heme-proximal side of the globin domain. Using hydrogen/deuterium exchange coupled with mass spectrometry to characterize the conformations of the active and inactive forms of full-length Af GcHK in solution, we investigated the intramolecular signal transduction mechanisms. Major differences between the active and inactive forms were observed on the heme-proximal side (helix H5), at the dimerization interface (helices H6 and H7 and loop L7) of the globin domain and in the ATP-binding site (helices H9 and H11) of the kinase domain. Moreover, separation of the sensor and kinase domains, which deactivates catalysis, increased the solvent exposure of the globin domain-dimerization interface (helix H6) as well as the flexibility and solvent exposure of helix H11. Together, these results suggest that structural changes at the heme-proximal side, the globin domain-dimerization interface, and the ATP-binding site are important in the signal transduction mechanism of Af GcHK. We conclude that Af GcHK functions as an ensemble of molecules sampling at least two conformational states. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Distinct mechanisms underlie adaptation of proximal tubule Na+/H+ exchanger isoform 3 in response to chronic metabolic and respiratory acidosis.

    Science.gov (United States)

    Silva, Pedro Henrique Imenez; Girardi, Adriana Castello Costa; Neri, Elida Adalgisa; Rebouças, Nancy Amaral

    2012-04-01

    The Na(+/)H(+) exchanger isoform 3 (NHE3) is essential for HCO(3)(-) reabsorption in renal proximal tubules. The expression and function of NHE3 must adapt to acid-base conditions. The goal of this study was to elucidate the mechanisms responsible for higher proton secretion in proximal tubules during acidosis and to evaluate whether there are differences between metabolic and respiratory acidosis with regard to NHE3 modulation and, if so, to identify the relevant parameters that may trigger these distinct adaptive responses. We achieved metabolic acidosis by lowering HCO(3)(-) concentration in the cell culture medium and respiratory acidosis by increasing CO(2) tension in the incubator chamber. We found that cell-surface NHE3 expression was increased in response to both forms of acidosis. Mild (pH 7.21 ± 0.02) and severe (6.95 ± 0.07) metabolic acidosis increased mRNA levels, at least in part due to up-regulation of transcription, whilst mild (7.11 ± 0.03) and severe (6.86 ± 0.01) respiratory acidosis did not up-regulate NHE3 expression. Analyses of the Nhe3 promoter region suggested that the regulatory elements sensitive to metabolic acidosis are located between -466 and -153 bp, where two consensus binding sites for SP1, a transcription factor up-regulated in metabolic acidosis, were localised. We conclude that metabolic acidosis induces Nhe3 promoter activation, which results in higher mRNA and total protein level. At the plasma membrane surface, NHE3 expression was increased in metabolic and respiratory acidosis alike, suggesting that low pH is responsible for NHE3 displacement to the cell surface.

  8. Signatures of a light sterile neutrino in T2HK

    Science.gov (United States)

    Agarwalla, Sanjib Kumar; Chatterjee, Sabya Sachi; Palazzo, Antonio

    2018-04-01

    We investigate the performance of T2HK in the presence of a light eV scale sterile neutrino. We study in detail its influence in resolving fundamental issues like mass hierarchy, CP-violation (CPV) induced by the standard CP-phase δ 13 and new CP-phase δ 14, and the octant ambiguity of θ 23. We show for the first time in detail that due to the impressive energy reconstruction capabilities of T2HK, the available spectral information plays an important role to enhance the mass hierarchy discovery reach of this experiment in 3 ν framework and also to keep it almost intact even in 4 ν scheme. This feature is also of the utmost importance in establishing the CPV due to δ 14. As far as the sensitivity to CPV due to δ 13 is concerned, it does not change much going from 3 ν to 4 ν case. We also examine the reconstruction capability of the two phases δ 13 and δ 14, and find that the typical 1 σ uncertainty on δ 13 ( δ 14) in T2HK is ˜ 150 (300). While determining the octant of θ 23, we face a complete loss of sensitivity for unfavorable combinations of unknown δ 13 and δ 14.

  9. hkösuodattimien vaikutus sähkön laatuun ja maadoituksen vaikutus sähkösuodattimiin

    OpenAIRE

    Vinho, Lauri

    2016-01-01

    Tässä opinnäytetyössä kerrotaan sähkömagneettisen säteilyn teoriasta ja yleisimmistä käyttökohteista. Työssä tutustutaan tarkemmin radiotaajuisen sähkömagneettisen säteilyn tehoon heijastukseen ja absorptioon, sekä radiotaajuisen sähkömagneettisen säteilyn sulkemiseen tilan sisä- tai ulkopuolelle faradayn -häkillä. Työssä esitellään lisäksi yleisesti erityyppisiä mittahuoneita, eli häiriösuojahuoneita, alle näkyvän valon sähkömagneettiselle säteilylle. Työssä perehdytään tarkemmin passiiv...

  10. hköautojen käyttäminen sähkövarastoina

    OpenAIRE

    Paju, Juuso

    2016-01-01

    hköautojen yleistyminen voi aiheuttaa ongelmia niiden latauksessa. Akut ovat kapasiteetiltaan aiempaa suurempia ja ne pitäisi ladata lyhyessä ajassa. 90 prosenttia sähköautojen latauksesta tulee tapahtumaan kotona, mutta pientalojen sähköjärjestelmien mitoituksissa ei aiemmin ole otettu huomioon sähköautojen latauspisteiden käyttämää suurta latausvirtaa. Tässä opinnäytetyössä oli tarkoitus tutkia sähköauton pientalossa tapahtuvan latauksen aikana esiintyviä virtoja, tehoja ja pääsulakke...

  11. Baicalin Ameliorates H2O2 Induced Cytotoxicity in HK-2 Cells through the Inhibition of ER Stress and the Activation of Nrf2 Signaling

    Directory of Open Access Journals (Sweden)

    Miao Lin

    2014-07-01

    Full Text Available Renal ischemia-reperfusion injury plays a key role in renal transplantation and greatly affects the outcome of allograft. Our previous study proved that Baicalin, a flavonoid glycoside isolated from Scutellaria baicalensis, protects kidney from ischemia-reperfusion injury. This study aimed to study the underlying mechanism in vitro. Human renal proximal tubular epithelial cell line HK-2 cells were stimulated by H2O2 with and without Baicalin pretreatment. The cell viability, apoptosis and oxidative stress level were measured. The expression of endoplasmic reticulum (ER stress hallmarks, such as binding immunoglobulin protein (BiP and C/EBP homologous protein (CHOP, were analyzed by western blot and real-time PCR. NF-E2-related factor 2 (Nrf2 expression was also measured. In the H2O2 group, cell viability decreased and cell apoptosis increased. Reactive Oxygen Species (ROS and Glutathione/Oxidized Glutathione (GSH/GSSG analysis revealed increased oxidative stress. ER stress and Nrf2 signaling also increased. Baicalin pretreatment ameliorated H2O2-induced cytotoxicity, reduced oxidative stress and ER stress and further activated the anti-oxidative Nrf2 signaling pathway. The inducer of ER stress and the inhibitor of Nrf2 abrogated the protective effects, while the inhibitor of ER stress and the inducer of Nrf2 did not improve the outcome. This study revealed that Baicalin pretreatment serves a protective role against H2O2-induced cytotoxicity in HK-2 cells, where the inhibition of ER stress and the activation of downstream Nrf2 signaling are involved.

  12. Transport of water in proximal kidney tubules from whole tubules to single channels: length and section of the selectivity filter of aquaporin-1.

    Science.gov (United States)

    Whittembury, G; González, E; Hernández, C S; Gutiérrez, A M; Echevarría, M

    1997-06-27

    Proximal straight tubule (PST) were dissected from rabbit kidneys, held with crimping pipettes in a chamber bathed in a buffered mannitol isosmotic solution (MBS, 295 mOsm/kg). Tubule cell volume changes with time (dV/Adt) after steps in MBS osmolality (delta Cs) were monitored on line with an inverted microscope, a TV camera and an image processor. Reflection coefficients sigma and osmotic permeability coefficients, Pos, for several solutes were measured using two methods. Method 1: sigma was calculated from the delta Csiso of impermeant and permeant solutes at which (dV/Adt)t-->0 = 0 (i.e., by a null point method). It is denoted as sigma 1. sigma 1 = 1.00 for mannitol (M), raffinose (R), sucrose (S), glycerol (G), acetamide (A) and urea (U). With formamide (F), sigma 1, Formamide = 0.62 +/- 0.05. These findings confirm our previous value of dp = 4.5 A for the diameter of the selectivity filter of the basolateral PST cell membrane water channel AQP1. Method 2: PST were exposed for 20 s to MBS made hyperosmotic by addition of a delta Cs of 35 mOsm/kg of R, S, M, G, A and U. Cells shrunk within 500 ms of t = 0 to their osmometric volume and remained shrunk for the 20 s of the osmotic challenge. Pos was measured from the shrinking curves. P(os) = 3000 +/- 25 microns/s with R, S, M, G, A and U. Method 2 also allowed to calculate sigma, denoted as sigma 2. sigma 2 = 1.00 for R, S, M, G, A and U. By contrast, the shrinking curve produced by a delta Cs of 35 mOsm/kg F was 1/5th to 1/6th slower and smaller (i.e., subosmometric) than that produced by a delta Cs of 35 mOsm/kg R, S, M, G, A and U. Furthermore, with F cells did not remain shrunk but recovered their original volume within 3 s. P(os) (measured with F) is denoted as P(os)*, P(os)* = 480 +/- 30 microns/s. sigma 2, Formamide = 0.16 +/- 0.01. Use of sigma 1, sigma 2 and P(os)* values in Hill's equations for the bimodal theory of osmosis leads to n = 2-9. Where n is the number of water molecules single filling

  13. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi-Fen; Shyu, Huey-Wen [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chang, Yi-Chuang [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China); Tseng, Wei-Chang [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chen, Chang-Yu, E-mail: mt037@mail.fy.edu.tw [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)

    2012-03-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  14. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Wang, Yi-Fen; Shyu, Huey-Wen; Chang, Yi-Chuang; Tseng, Wei-Chang; Huang, Yeou-Lih; Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling; Chen, Chang-Yu

    2012-01-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  15. Association of HK2 and NCK2 with normal tension glaucoma in the Japanese population.

    Directory of Open Access Journals (Sweden)

    Dong Shi

    Full Text Available Although family studies and genome-wide association studies have shown that genetic factors play a role in glaucoma, it has been difficult to identify the specific genetic variants involved. We tested 669 single nucleotide polymorphisms (SNPs from the region of chromosome 2 that includes the GLC1B glaucoma locus for association with primary open-angle glaucoma (POAG and normal tension glaucoma (NTG in the Japanese population. We performed a two-stage case-control study. The first cohort consisted of 123 POAG cases, 121 NTG cases and 120 controls: the second cohort consisted of 187 POAG cases, 286 NTG cases, and 271 controls. Out of six SNPs showing significant association with POAG in the first round screening, seven SNPs were tested in the second round. Rs678350 in the HK2 gene coding sequence showed significant allelic (p=0.0027 in Stage Two, 2.7XE-4 in meta-analysis association with POAG, and significant allelic (p=4.7XE-4 in Stage Two, 1.0XE-5 in meta-analysis association with NTG. Although alleles in the TMEM182 gene did not show significant association with glaucoma in the second round, subjects with the A/A allele in TMEM182 rs869833 showed worse visual field mean deviation (p=0.01. Even though rs2033008 in the NCK2 gene coding sequence did not show significant association in the first round, it had previously shown association with NTG so it was tested for association with NTG in round 2 (p=0.0053 in Stage Two. Immunohistochemistry showed that both HK2 and NCK2 are expressed in the retinal ganglion cell layer. Once multi-testing was taken into account, only HK2 showed significant association with POAG and NTG in Stage Two. Our data also support previous reports of NCK2 association with NTG, and raise questions about what role TMEM182 might play in phenotypic variability. Our data suggest that HK2 may play an important role in NTG in the Japanese population.

  16. Induction of apoptosis in cultured human proximal tubule cells by fumonisins and fumonisin metabolites

    International Nuclear Information System (INIS)

    Seefelder, W.; Humpf, H.-U.; Schwerdt, G.; Freudinger, R.; Gekle, M.

    2003-01-01

    Fumonisin B 1 (FB 1 ) causes apoptosis in a variety of cell types and tissues but the apoptotic potential of other fumonisins and fumonisin metabolites has not been determined and the underlying mechanisms are not completely understood. In our studies we exposed human proximal tubule-derived cells (IHKE cells) to FB 1 , fumonisin B 2 (FB 2 ), fumonisin B 3 (FB 3 ), hydrolyzed fumonisin B 1 (HFB 1 ) and N-palmitoyl-hydrolyzed fumonisin B 1 (N-Pal-HFB 1 ) and investigated caspase-3 activation, chromatin condensation and DNA fragmentation. Exposure to 10 μmol/L FB 1 for 24 h led to a significant increase in caspase-3 activity, chromatin condensation and to DNA fragmentation. All other tested compounds did not show any significant activation of caspase-3 activity nor chromatin condensation and DNA-fragmentation. Furthermore, we examined if a sphinganine accumulation is correlated with an induction of apoptosis in IHKE cells. Therefore we used a liquid chromatography/electrospray ionization-mass spectrometry(LC/ESI-MS)-method using phytosphingosine as an internal standard to determine sphinganine and sphingosine concentrations in IHKE cells. Whereas a significant increase of sphinganine (up to 7000% compared to control cells) was observed with all fumonisin-derivates, sphingosine levels nearly remained unchanged indicating that all substrates inhibited ceramide synthase effectively. These results demonstrate that all compounds let to increased sphinganine levels in IHKE cells but only FB 1 was able to induce apoptosis. We conclude that the inhibition of the ceramide synthase is not per se a predictor whether or not fumonisins induce apoptosis

  17. Nonstandard neutrino interactions at DUNE, T2HK and T2HKK

    International Nuclear Information System (INIS)

    Liao, Jiajun; Marfatia, Danny; Whisnant, Kerry

    2017-01-01

    Here, we study the matter effect caused by nonstandard neutrino interactions (NSI) in the next generation long-baseline neutrino experiments, DUNE, T2HK and T2HKK. If multiple NSI parameters are nonzero, the potential of these experiments to detect CP violation, determine the mass hierarchy and constrain NSI is severely impaired by degeneracies between the NSI parameters and by the generalized mass hierarchy degeneracy. In particular, a cancellation between leading order terms in the appearance channels when ϵ_e_τ= cot θ _2_3ϵ_e_μ, strongly affects the sensitivities to these two NSI parameters at T2HK and T2HKK. We also study the dependence of the sensitivities on the true CP phase and the true mass hierarchy, and find that overall DUNE has the best sensitivity to the magnitude of the NSI parameters, while T2HKK has the best sensitivity to CP violation whether or not there are NSI. Furthermore, for T2HKK a smaller off-axis angle for the Korean detector is better overall. We find that due to the structure of the leading order terms in the appearance channel probabilities, the NSI sensitivities in a given experiment are similar for both mass hierarchies, modulo the phase change δ→δ + 180°.

  18. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chun-Yu [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Chao-Yu [School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Kang, Chao-Kai [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Sher, Yuh-Pyng [Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan (China); Sheu, Wayne H.-H. [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan (China); School of Medicine, National Yang Ming University, Taipei, Taiwan (China); School of Medicine, National Defense Medical Center, Taipei, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Lee, Tsung-Han, E-mail: thlee@email.nchu.edu.tw [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Department of Biological Science and Technology, China Medical University, Taichung, Taiwan (China)

    2014-09-15

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation.

  19. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    International Nuclear Information System (INIS)

    Chang, Chun-Yu; Shen, Chao-Yu; Kang, Chao-Kai; Sher, Yuh-Pyng; Sheu, Wayne H.-H.; Chang, Chia-Che; Lee, Tsung-Han

    2014-01-01

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation

  20. Smad mediated regulation of inhibitor of DNA binding 2 and its role in phenotypic maintenance of human renal proximal tubule epithelial cells.

    Directory of Open Access Journals (Sweden)

    Mangalakumar Veerasamy

    Full Text Available The basic-Helix-Loop-Helix family (bHLH of transcriptional factors plays a major role in regulating cellular proliferation, differentiation and phenotype maintenance. The downregulation of one of the members of bHLH family protein, inhibitor of DNA binding 2 (Id2 has been shown to induce de-differentiation of epithelial cells. Opposing regulators of epithelial/mesenchymal phenotype in renal proximal tubule epithelial cells (PTEC, TGFβ1 and BMP7 also have counter-regulatory effects in models of renal fibrosis. We investigated the regulation of Id2 by these growth factors in human PTECs and its implication in the expression of markers of epithelial versus myofibroblastic phenotype. Cellular Id2 levels were reduced by TGFβ1 treatment; this was prevented by co-incubation with BMP7. BMP7 alone increased cellular levels of Id2. TGFβ1 and BMP7 regulated Id2 through Smad2/3 and Smad1/5 dependent mechanisms respectively. TGFβ1 mediated Id2 suppression was essential for α-SMA induction in PTECs. Although Id2 over-expression prevented α-SMA induction, it did not prevent E-cadherin loss under the influence of TGFβ1. This suggests that the loss of gate keeper function of E-cadherin alone may not necessarily result in complete EMT and further transcriptional re-programming is essential to attain mesenchymal phenotype. Although BMP7 abolished TGFβ1 mediated α-SMA expression by restoring Id2 levels, the loss of Id2 was not sufficient to induce α-SMA expression even in the context of reduced E-cadherin expression. Hence, a reduction in Id2 is critical for TGFβ1-induced α-SMA expression in this model of human PTECs but is not sufficient in it self to induce α-SMA even in the context of reduced E-cadherin.

  1. MicroRNA-98 Suppress Warburg Effect by Targeting HK2 in Colon Cancer Cells.

    Science.gov (United States)

    Zhu, Weimin; Huang, Yijiao; Pan, Qi; Xiang, Pei; Xie, Nanlan; Yu, Hao

    2017-03-01

    Warburg effect is a hallmark of cancer cells. Accumulating evidence suggests that microRNAs (miRs) could regulate such metabolic reprograming. Aberrant expression of miR-98 has been observed in many types of cancers. However, its functions and significance in colon cancer remain largely elusive. To investigate miR-98 expression and the biological functions in colon cancer progression. miR-98 expression levels were determined by quantitative RT-PCR in 215 cases of colon cancer samples. miR-98 mimic or inhibitor was used to test the biological functions in SW480 and HCT116 cells, followed by cell proliferation assay, lactate production, glucose uptake, and cellular ATP levels assay and extracellular acidification rates measurement. Western blot and luciferase assay were used to identify the target of miR-98. miR-98 was significantly down-regulated in colon cancer tissues compared to adjacent colon tissues and acted as a suppressor for Warburg effect in cancer cells. miR-98 inhibited glycolysis by directly targeting hexokinase 2, or HK2, illustrating a novel pathway to mediate Warburg effect of cancer cells. In vitro experiments further indicated that HK2 was involved in miR-98-mediated suppression of glucose uptake, lactate production, and cell proliferation. In addition, we detected HK2 expression in colon cancer tissues and found that the expressions of miR-98 and HK2 were negatively correlated. miR-98 acts as tumor suppressor gene and inhibits Warburg effect in colon cancer cells, which provided potential targets for clinical treatments.

  2. Induction of apoptosis in cultured human proximal tubule cells by fumonisins and fumonisin metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Seefelder, W; Humpf, H -U; Schwerdt, G; Freudinger, R; Gekle, M

    2003-10-15

    Fumonisin B{sub 1} (FB{sub 1}) causes apoptosis in a variety of cell types and tissues but the apoptotic potential of other fumonisins and fumonisin metabolites has not been determined and the underlying mechanisms are not completely understood. In our studies we exposed human proximal tubule-derived cells (IHKE cells) to FB{sub 1}, fumonisin B{sub 2} (FB{sub 2}), fumonisin B{sub 3} (FB{sub 3}), hydrolyzed fumonisin B{sub 1} (HFB{sub 1}) and N-palmitoyl-hydrolyzed fumonisin B{sub 1} (N-Pal-HFB{sub 1}) and investigated caspase-3 activation, chromatin condensation and DNA fragmentation. Exposure to 10 {mu}mol/L FB{sub 1} for 24 h led to a significant increase in caspase-3 activity, chromatin condensation and to DNA fragmentation. All other tested compounds did not show any significant activation of caspase-3 activity nor chromatin condensation and DNA-fragmentation. Furthermore, we examined if a sphinganine accumulation is correlated with an induction of apoptosis in IHKE cells. Therefore we used a liquid chromatography/electrospray ionization-mass spectrometry(LC/ESI-MS)-method using phytosphingosine as an internal standard to determine sphinganine and sphingosine concentrations in IHKE cells. Whereas a significant increase of sphinganine (up to 7000% compared to control cells) was observed with all fumonisin-derivates, sphingosine levels nearly remained unchanged indicating that all substrates inhibited ceramide synthase effectively. These results demonstrate that all compounds let to increased sphinganine levels in IHKE cells but only FB{sub 1} was able to induce apoptosis. We conclude that the inhibition of the ceramide synthase is not per se a predictor whether or not fumonisins induce apoptosis.

  3. A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer.

    Science.gov (United States)

    Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

    2015-05-22

    Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10(-4) to 10(2) ng/mL).

  4. Antenatal betamethasone attenuates the angiotensin-(1-7)-Mas receptor-nitric oxide axis in isolated proximal tubule cells.

    Science.gov (United States)

    Su, Yixin; Bi, Jianli; Pulgar, Victor M; Chappell, Mark C; Rose, James C

    2017-06-01

    We previously reported a sex-specific effect of antenatal treatment with betamethasone (Beta) on sodium (Na + ) excretion in adult sheep whereby treated males but not females had an attenuated natriuretic response to angiotensin-(1-7) [Ang-(1-7)]. The present study determined the Na + uptake and nitric oxide (NO) response to low-dose Ang-(1-7) (1 pM) in renal proximal tubule cells (RPTC) from adult male and female sheep antenatally exposed to Beta or vehicle. Data were expressed as percentage of basal uptake or area under the curve for Na + or percentage of control for NO. Male Beta RPTC exhibited greater Na + uptake than male vehicle cells (433 ± 28 vs. 330 ± 26%; P 0.05). Ang-(1-7) significantly inhibited Na + uptake in RPTC from vehicle male (214 ± 11%) and from both vehicle (190 ± 14%) and Beta (209 ± 11%) females but failed to attenuate Na + uptake in Beta male cells. Beta exposure also abolished stimulation of NO by Ang-(1-7) in male but not female RPTC. Both the Na + and NO responses to Ang-(1-7) were blocked by Mas receptor antagonist d-Ala 7 -Ang-(1-7). We conclude that the tubular Ang-(1-7)-Mas-NO pathway is attenuated in males and not females by antenatal Beta exposure. Moreover, since primary cultures of RPTC retain both the sex and Beta-induced phenotype of the adult kidney in vivo they appear to be an appropriate cell model to examine the effects of fetal programming on Na + handling by the renal tubules. Copyright © 2017 the American Physiological Society.

  5. hkösuunnitelmien luovutusdokumentointi

    OpenAIRE

    Lautamäki, Jouni

    2013-01-01

    Tämän opinnäytetyön tavoitteena oli luoda viralliset luovutusdokumentit asuntoosakeyhtiö Ilokkaanrinteen putkistosaneerauksen sähkösuunnitelmista. Kohteen saneeraus sisälsi taloyhtiön 46 asunnon kylpyhuoneiden sekä keittiöiden sähköjen uusimisen. Lisäksi kiinteistön yleisten tilojen sähköasennukset uusittiin lähes kokonaan. Tässä opinnäytetyössä haluan antaa lukijalle mahdollisimman selkeän kuvan luovutusdokumentoinnin tarkoituksesta ja sen laadinnasta. Lisäksi selvitän, mitä standardi S...

  6. SIRT1 overexpression decreases cisplatin-induced acetylation of NF-κB p65 subunit and cytotoxicity in renal proximal tubule cells

    International Nuclear Information System (INIS)

    Jung, Yu Jin; Lee, Jung Eun; Lee, Ae Sin; Kang, Kyung Pyo; Lee, Sik; Park, Sung Kwang; Lee, Sang Yong; Han, Myung Kwan; Kim, Duk Hoon; Kim, Won

    2012-01-01

    Highlights: ► Cisplatin increases acetylation of NF-κB p65 subunit in HK2 cells. ► SIRT1 overexpression decreases cisplatin-induced p65 acetylation and -cytotoxicity. ► Resveratrol decreased cisplatin-induced cell viability through deacetylation of p65. -- Abstract: As the increased acetylation of p65 is linked to nuclear factor-κB (NF-κB) activation, the regulation of p65 acetylation can be a potential target for the treatment of inflammatory injury. Cisplatin-induced nephrotoxicity is an important issue in chemotherapy of cancer patients. SIRT1, nicotinamide adenine dinucleotide (NAD + )-dependent protein deacetylase, has been implicated in a variety of cellular processes such as inflammatory injury and the control of multidrug resistance in cancer. However, there is no report on the effect of SIRT1 overexpression on cisplatin-induced acetylation of p65 subunit of NF-κB and cell injury. To investigate the effect of SIRT1 in on cisplatin-induced acetylation of p65 subunit of NF-κB and cell injury, HK2 cells were exposed with SIRT1 overexpression, LacZ adenovirus or dominant negative adenovirus after treatment with cisplatin. While protein expression of SIRT1 was decreased by cisplatin treatment compared with control buffer treatment, acetylation of NF-κB p65 subunit was significantly increased after treatment with cisplatin. Overexpression of SIRT1 ameliorated the increased acetylation of p65 of NF-κB during cisplatin treatment and cisplatin-induced cytotoxicity. Further, treatment of cisplatin-treated HK2 cells with resveratrol, a SIRT1 activator, also decreased acetylation of NF-κB p65 subunit and cisplatin-induced increase of the cell viability in HK2 cells. Our findings suggests that the regulation of acetylation of p65 of NF-κB through SIRT1 can be a possible target to attenuate cisplatin-induced renal cell damage.

  7. Cadmium induces Wnt signaling to upregulate proliferation and survival genes in sub-confluent kidney proximal tubule cells

    Directory of Open Access Journals (Sweden)

    Wolff Natascha A

    2010-05-01

    Full Text Available Abstract Background The class 1 carcinogen cadmium (Cd2+ disrupts the E-cadherin/β-catenin complex of epithelial adherens junctions (AJs and causes renal cancer. Deregulation of E-cadherin adhesion and changes in Wnt/β-catenin signaling are known to contribute to carcinogenesis. Results We investigated Wnt signaling after Cd2+-induced E-cadherin disruption in sub-confluent cultured kidney proximal tubule cells (PTC. Cd2+ (25 μM, 3-9 h caused nuclear translocation of β-catenin and triggered a Wnt response measured by TOPflash reporter assays. Cd2+ reduced the interaction of β-catenin with AJ components (E-cadherin, α-catenin and increased binding to the transcription factor TCF4 of the Wnt pathway, which was upregulated and translocated to the nucleus. While Wnt target genes (c-Myc, cyclin D1 and ABCB1 were up-regulated by Cd2+, electromobility shift assays showed increased TCF4 binding to cyclin D1 and ABCB1 promoter sequences with Cd2+. Overexpression of wild-type and mutant TCF4 confirmed Cd2+-induced Wnt signaling. Wnt signaling elicited by Cd2+ was not observed in confluent non-proliferating cells, which showed increased E-cadherin expression. Overexpression of E-cadherin reduced Wnt signaling, PTC proliferation and Cd2+ toxicity. Cd2+ also induced reactive oxygen species dependent expression of the pro-apoptotic ER stress marker and Wnt suppressor CHOP/GADD153 which, however, did not abolish Wnt response and cell viability. Conclusions Cd2+ induces Wnt signaling in PTC. Hence, Cd2+ may facilitate carcinogenesis of PTC by promoting Wnt pathway-mediated proliferation and survival of pre-neoplastic cells.

  8. Quantifying cellular mechanics and adhesion in renal tubular injury using single cell force spectroscopy.

    Science.gov (United States)

    Siamantouras, Eleftherios; Hills, Claire E; Squires, Paul E; Liu, Kuo-Kang

    2016-05-01

    Tubulointerstitial fibrosis represents the major underlying pathology of diabetic nephropathy where loss of cell-to-cell adhesion is a critical step. To date, research has predominantly focussed on the loss of cell surface molecular binding events that include altered protein ligation. In the current study, atomic force microscopy single cell force spectroscopy (AFM-SCFS) was used to quantify changes in cellular stiffness and cell adhesion in TGF-β1 treated kidney cells of the human proximal tubule (HK2). AFM indentation of TGF-β1 treated HK2 cells showed a significant increase (42%) in the elastic modulus (stiffness) compared to control. Fluorescence microscopy confirmed that increased cell stiffness is accompanied by reorganization of the cytoskeleton. The corresponding changes in stiffness, due to F-actin rearrangement, affected the work of detachment by changing the separation distance between two adherent cells. Overall, our novel data quantitatively demonstrate a correlation between cellular elasticity, adhesion and early morphologic/phenotypic changes associated with tubular injury. Diabetes affects many patients worldwide. One of the long term problems is diabetic nephropathy. Here, the authors utilized atomic force microscopy single cell force spectroscopy (AFM- SCFS) to study cellular stiffness and cell adhesion after TGF1 treatment in human proximal tubule kidney cells. The findings would help further understand the overall disease mechanism in diabetic patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. The sodium-bicarbonate cotransporter NBCe2 (slc4a5) expressed in human renal proximal tubules shows increased apical expression under high-salt conditions.

    Science.gov (United States)

    Gildea, John J; Xu, Peng; Carlson, Julia M; Gaglione, Robert T; Bigler Wang, Dora; Kemp, Brandon A; Reyes, Camellia M; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2015-12-01

    The electrogenic sodium bicarbonate cotransporter (NBCe2) is encoded by SLC4A5, variants of which have been associated with salt sensitivity of blood pressure, which affects 25% of the adult population. NBCe2 is thought to mediate sodium bicarbonate cotransport primarily in the renal collecting duct, but NBCe2 mRNA is also found in the rodent renal proximal tubule (RPT). The protein expression or function of NBCe2 has not been demonstrated in the human RPT. We validated an NBCe2 antibody by shRNA and Western blot analysis, as well as overexpression of an epitope-tagged NBCe2 construct in both RPT cells (RPTCs) and human embryonic kidney 293 (HEK293) cells. Using this validated NBCe2 antibody, we found NBCe2 protein expression in the RPT of fresh and frozen human kidney slices, RPTCs isolated from human urine, and isolated RPTC apical membrane. Under basal conditions, NBCe2 was primarily found in the Golgi, while NBCe1 was primarily found at the basolateral membrane. Following an acute short-term increase in intracellular sodium, NBCe2 expression was increased at the apical membrane in cultured slices of human kidney and polarized, immortalized RPTCs. Sodium bicarbonate transport was increased by monensin and overexpression of NBCe2, decreased by NBCe2 shRNA, but not by NBCe1 shRNA, and blocked by 2,2'-(1,2-ethenediyl)bis[5-isothiocyanato-benzenesulfonic acid]. NBCe2 could be important in apical sodium and bicarbonate cotransport under high-salt conditions; the implication of the ex vivo studies to the in vivo situation when salt intake is increased remains unclear. Therefore, future studies will examine the role of NBCe2 in mediating increased renal sodium transport in humans whose blood pressures are elevated by an increase in sodium intake. Copyright © 2015 the American Physiological Society.

  10. Sodium bicarbonate cotransporter NBCe2 gene variants increase sodium and bicarbonate transport in human renal proximal tubule cells.

    Science.gov (United States)

    Gildea, John J; Xu, Peng; Kemp, Brandon A; Carlson, Julia M; Tran, Hanh T; Bigler Wang, Dora; Langouët-Astrié, Christophe J; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2018-01-01

    Salt sensitivity of blood pressure affects >30% of the hypertensive and >15% of the normotensive population. Variants of the electrogenic sodium bicarbonate cotransporter NBCe2 gene, SLC4A5, are associated with increased blood pressure in several ethnic groups. SLC4A5 variants are also highly associated with salt sensitivity, independent of hypertension. However, little is known about how NBCe2 contributes to salt sensitivity, although NBCe2 regulates renal tubular sodium bicarbonate transport. We hypothesized that SLC4A5 rs10177833 and rs7571842 increase NBCe2 expression and human renal proximal tubule cell (hRPTC) sodium transport and may be a cause of salt sensitivity of blood pressure. To characterize the hRPTC ion transport of wild-type (WT) and homozygous variants (HV) of SLC4A5. The expressions of NBCe2 mRNA and protein were not different between hRPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, luminal to basolateral sodium transport, NHE3 protein, and Cl-/HCO3- exchanger activity in hRPTCs were higher in HV than WT SLC4A5. Increasing intracellular sodium enhanced the apical location of NBCe2 in HV hRPTCs (4.24±0.35% to 11.06±1.72% (P<0.05, N = 3, 2-way ANOVA, Holm-Sidak test)) as determined by Total Internal Reflection Fluorescence Microscopy (TIRFM). In hRPTCs isolated from kidney tissue, increasing intracellular sodium enhanced bicarbonate-dependent pH recovery rate and increased NBCe2 mRNA and protein expressions to a greater extent in HV than WT SLC4A5 (+38.00±6.23% vs HV normal salt (P<0.01, N = 4, 2-way ANOVA, Holm-Sidak test)). In hRPTCs isolated from freshly voided urine, bicarbonate-dependent pH recovery was also faster in those from salt-sensitive and carriers of HV SLC4A5 than from salt-resistant and carriers of WT SLC4A5. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was normalized by SLC4A5- but not SLC4A4-shRNA. The binding of purified hepatocyte

  11. Developmentally regulated GTP-binding protein 2 is required for stabilization of Rac1-positive membrane tubules.

    Science.gov (United States)

    Mani, Muralidharan; Lee, Unn Hwa; Yoon, Nal Ae; Yoon, Eun Hye; Lee, Byung Ju; Cho, Wha Ja; Park, Jeong Woo

    2017-11-04

    Previously we have reported that developmentally regulated GTP-binding protein 2 (DRG2) localizes on Rab5 endosomes and plays an important role in transferrin (Tfn) recycling. We here identified DRG2 as a key regulator of membrane tubule stability. At 30 min after Tfn treatment, DRG2 localized to membrane tubules which were enriched with phosphatidylinositol 4-monophosphate [PI(4)P] and did not contain Rab5. DRG2 interacted with Rac1 more strongly with GTP-bound Rac1 and tubular localization of DRG2 depended on Rac1 activity. DRG2 depletion led to destabilization of membrane tubules, while ectopic expression of DRG2 rescued the stability of the membrane tubules in DRG2-depleted cells. Our results reveal a novel mechanism for regulation of membrane tubule stability mediated by DRG2. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Cationic uremic toxins affect human renal proximal tubule cell functioning through interaction with the organic cation transporter.

    Science.gov (United States)

    Schophuizen, Carolien M S; Wilmer, Martijn J; Jansen, Jitske; Gustavsson, Lena; Hilgendorf, Constanze; Hoenderop, Joost G J; van den Heuvel, Lambert P; Masereeuw, Rosalinde

    2013-12-01

    Several organic cations, such as guanidino compounds and polyamines, have been found to accumulate in plasma of patients with kidney failure due to inadequate renal clearance. Here, we studied the interaction of cationic uremic toxins with renal organic cation transport in a conditionally immortalized human proximal tubule epithelial cell line (ciPTEC). Transporter activity was measured and validated in cell suspensions by studying uptake of the fluorescent substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium-iodide (ASP(+)). Subsequently, the inhibitory potencies of the cationic uremic toxins, cadaverine, putrescine, spermine and spermidine (polyamines), acrolein (polyamine breakdown product), guanidine, and methylguanidine (guanidino compounds) were determined. Concentration-dependent inhibition of ASP(+) uptake by TPA, cimetidine, quinidine, and metformin confirmed functional endogenous organic cation transporter 2 (OCT2) expression in ciPTEC. All uremic toxins tested inhibited ASP(+) uptake, of which acrolein required the lowest concentration to provoke a half-maximal inhibition (IC50 = 44 ± 2 μM). A Dixon plot was constructed for acrolein using three independent inhibition curves with 10, 20, or 30 μM ASP(+), which demonstrated competitive or mixed type of interaction (K i = 93 ± 16 μM). Exposing the cells to a mixture of cationic uremic toxins resulted in a more potent and biphasic inhibitory response curve, indicating complex interactions between the toxins and ASP(+) uptake. In conclusion, ciPTEC proves a suitable model to study cationic xenobiotic interactions. Inhibition of cellular uptake transport was demonstrated for several uremic toxins, which might indicate a possible role in kidney disease progression during uremia.

  13. SIRT1 overexpression decreases cisplatin-induced acetylation of NF-{kappa}B p65 subunit and cytotoxicity in renal proximal tubule cells

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yu Jin; Lee, Jung Eun; Lee, Ae Sin [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kang, Kyung Pyo; Lee, Sik; Park, Sung Kwang [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Lee, Sang Yong [Department of Diagnostic Radiology, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Han, Myung Kwan [Department of Microbiology, Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Duk Hoon [Division of Forensic Medicine, National Forensic Service, Seoul (Korea, Republic of); Kim, Won, E-mail: kwon@jbnu.ac.kr [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Cisplatin increases acetylation of NF-{kappa}B p65 subunit in HK2 cells. Black-Right-Pointing-Pointer SIRT1 overexpression decreases cisplatin-induced p65 acetylation and -cytotoxicity. Black-Right-Pointing-Pointer Resveratrol decreased cisplatin-induced cell viability through deacetylation of p65. -- Abstract: As the increased acetylation of p65 is linked to nuclear factor-{kappa}B (NF-{kappa}B) activation, the regulation of p65 acetylation can be a potential target for the treatment of inflammatory injury. Cisplatin-induced nephrotoxicity is an important issue in chemotherapy of cancer patients. SIRT1, nicotinamide adenine dinucleotide (NAD{sup +})-dependent protein deacetylase, has been implicated in a variety of cellular processes such as inflammatory injury and the control of multidrug resistance in cancer. However, there is no report on the effect of SIRT1 overexpression on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury. To investigate the effect of SIRT1 in on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury, HK2 cells were exposed with SIRT1 overexpression, LacZ adenovirus or dominant negative adenovirus after treatment with cisplatin. While protein expression of SIRT1 was decreased by cisplatin treatment compared with control buffer treatment, acetylation of NF-{kappa}B p65 subunit was significantly increased after treatment with cisplatin. Overexpression of SIRT1 ameliorated the increased acetylation of p65 of NF-{kappa}B during cisplatin treatment and cisplatin-induced cytotoxicity. Further, treatment of cisplatin-treated HK2 cells with resveratrol, a SIRT1 activator, also decreased acetylation of NF-{kappa}B p65 subunit and cisplatin-induced increase of the cell viability in HK2 cells. Our findings suggests that the regulation of acetylation of p65 of NF-{kappa}B through SIRT1 can be a possible target to attenuate cisplatin-induced renal cell damage.

  14. The transcriptome of the Didelphis virginiana opossum kidney OK proximal tubule cell line.

    Science.gov (United States)

    Eshbach, Megan L; Sethi, Rahil; Avula, Raghunandan; Lamb, Janette; Hollingshead, Deborah J; Finegold, David N; Locker, Joseph D; Chandran, Uma R; Weisz, Ora A

    2017-09-01

    The OK cell line derived from the kidney of a female opossum Didelphis virginiana has proven to be a useful model in which to investigate the unique regulation of ion transport and membrane trafficking mechanisms in the proximal tubule (PT). Sequence data and comparison of the transcriptome of this cell line to eutherian mammal PTs would further broaden the utility of this culture model. However, the genomic sequence for D. virginiana is not available and although a draft genome sequence for the opossum Monodelphis domestica (sequenced in 2012 by the Broad Institute) exists, transcripts sequenced from both species show significant divergence. The M. domestica sequence is not highly annotated, and the majority of transcripts are predicted rather than experimentally validated. Using deep RNA sequencing of the D. virginiana OK cell line, we characterized its transcriptome via de novo transcriptome assembly and alignment to the M. domestica genome. The quality of the de novo assembled transcriptome was assessed by the extent of homology to sequences in nucleotide and protein databases. Gene expression levels in the OK cell line, from both the de novo transcriptome and genes aligned to the M. domestica genome, were compared with publicly available rat kidney nephron segment expression data. Our studies demonstrate the expression in OK cells of numerous PT-specific ion transporters and other key proteins relevant for rodent and human PT function. Additionally, the sequence and expression data reported here provide an important resource for genetic manipulation and other studies on PT cell function using these cells. Copyright © 2017 the American Physiological Society.

  15. Proximal Tubular Injury in Medullary Rays Is an Early Sign of Acute Tacrolimus Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Diane Cosner

    2015-01-01

    Full Text Available Tacrolimus (FK506 is one of the principal immunosuppressive agents used after solid organ transplantations to prevent allograft rejection. Chronic renal injury induced by tacrolimus is characterized by linear fibrosis in the medullary rays; however, the early morphologic findings of acute tacrolimus nephrotoxicity are not well characterized. Kidney injury molecule-1 (KIM-1 is a specific injury biomarker that has been proven to be useful in the diagnosis of mild to severe acute tubular injury on renal biopsies. This study was motivated by a patient with acute kidney injury associated with elevated serum tacrolimus levels in whom KIM-1 staining was present only in proximal tubules located in the medullary rays in the setting of otherwise normal light, immunofluorescent, and electron microscopy. We subsequently evaluated KIM-1 expression in 45 protocol and 39 indicated renal transplant biopsies to determine whether higher serum levels of tacrolimus were associated with acute segment specific injury to the proximal tubule, as reflected by KIM-1 staining in the proximal tubules of the cortical medullary rays. The data suggest that tacrolimus toxicity preferentially affects proximal tubules in medullary rays and that this targeted injury is a precursor lesion for the linear fibrosis seen in chronic tacrolimus toxicity.

  16. Tacrolimus Modulates TGF-β Signaling to Induce Epithelial-Mesenchymal Transition in Human Renal Proximal Tubule Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Jason Bennett

    2016-04-01

    Full Text Available Epithelial-mesenchymal transition (EMT, a process which describes the trans-differentiation of epithelial cells into motile mesenchymal cells, is pivotal in stem cell behavior, development and wound healing, as well as contributing to disease processes including fibrosis and cancer progression. Maintenance immunosuppression with calcineurin inhibitors (CNIs has become routine management for renal transplant patient, but unfortunately the nephrotoxicity of these drugs has been well documented. HK-2 cells were exposed to Tacrolimus (FK506 and EMT markers were assessed by RT PCR and western blot. FK506 effects on TGF-β mRNA were assessed by RT PCR and TGF-β secretion was measured by ELISA. The impact of increased TGF-β secretion on Smad signaling pathways was investigated. The impact of inhibition of TGF-β signaling on EMT processes was assessed by scratch-wound assay. The results presented in this study suggest that FK506 initiates EMT processes in the HK-2 cell line, with altered expression of epithelial and myofibroblast markers evident. Additionally, the study demonstrates that FK506 activation of the TGF-β/ SMAD pathways is an essential step in the EMT process. Overall the results demonstrate that EMT is heavily involved in renal fibrosis associated with CNI nephrotoxicity.

  17. AC/DC-piirien mitoitus sähköasematoimituksissa

    OpenAIRE

    Rautarinta, Juha

    2015-01-01

    Tämän opinnäytetyön tarkoituksena oli tutkia Akku- ja Mitoitus-ohjelmia sekä selvittää niiden soveltuvuutta sähköasemien apusähköjärjestelmien mitoitukseen. Ohjelmia käytettiin VEO Oy:n toimittaman 110/20 kV:n sähköaseman tasasähköpiirien mitoituksen tutkimiseen. Työn alkuun on kerätty teoriaa etenkin sähköasemien tasasähköjärjestelmien mitoituksessa huomioon otettavista asioista ja standardeista. Lopussa käydään läpi ohjelmien käyttöä, ohjelman käyttämiä laskumenetelmiä ja kaavoja. ...

  18. A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

    1990-01-01

    Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...

  19. ePorsche : Jarrutustehon talteenotto sähköajoneuvoissa

    OpenAIRE

    Saarni, Atte

    2011-01-01

    Tämän opinnäytteen tarkoitus oli tutustua sähköajoneuvojen jarrutustehontalteenottojär-jestelmiin, suunnitella superkondensaattorimoduulilla toteutettava talteenottojärjestelmä ePorsche 928 sähkökonversiota varten ja tutkia sähköajoneuvossa käytettävän teho-elektroniikan sovelluksia ja mahdollisuuksia. ePorsche projekti on tehty yhteistyössä Tampereen Ammattikorkeakoulun, Tampereen Ammattiopiston ja Tampereen Sähkö-ajoneuvokeskuksen kanssa. Opinnäytetyössä käsitellään sähköisiä, mekaanisi...

  20. hköisen markkinointiviestinnän kehittäminen B2B-yrityksen näkökulmasta : Case: Yritys X

    OpenAIRE

    Pehkonen, Tuire

    2011-01-01

    Opinnäytetyön toimeksiantaja on asiantuntijapalveluyritys, Yritys X, joka tarjoaa informaatioteknologiapalveluita B2B-markkinoille. Opinnäytetyön aihe on B2B-yrityksen sähköinen markkinointiviestintä, jota käsitellään myös asiantuntijapalveluyrityksen näkökulmasta. Yritykseen liittyvät nimet on muutettu anonymiteetin suojelemiseksi. Työn tavoitteena on kehittää Yritys X:n sähköistä markkinointiviestintää, erityisesti sosiaalisen median osa-aluetta, mutta myös sähköpostimarkkinointia. ...

  1. Inhibition of CPU0213, a Dual Endothelin Receptor Antagonist, on Apoptosis via Nox4-Dependent ROS in HK-2 Cells

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-06-01

    Full Text Available Background/Aims: Our previous studies have indicated that a novel endothelin receptor antagonist CPU0213 effectively normalized renal function in diabetic nephropathy. However, the molecular mechanisms mediating the nephroprotective role of CPU0213 remain unknown. Methods and Results: In the present study, we first detected the role of CPU0213 on apoptosis in human renal tubular epithelial cell (HK-2. It was shown that high glucose significantly increased the protein expression of Bax and decreased Bcl-2 protein in HK-2 cells, which was reversed by CPU0213. The percentage of HK-2 cells that showed Annexin V-FITC binding was markedly suppressed by CPU0213, which confirmed the inhibitory role of CPU0213 on apoptosis. Given the regulation of endothelin (ET system to oxidative stress, we determined the role of redox signaling in the regulation of CPU0213 on apoptosis. It was demonstrated that the production of superoxide (O2-. was substantially attenuated by CPU0213 treatment in HK-2 cells. We further found that CPU0213 dramatically inhibited expression of Nox4 protein, which gene silencing mimicked the role of CPU0213 on the apoptosis under high glucose stimulation. We finally examined the role of CPU0213 on ET-1 receptors and found that high glucose-induced protein expression of endothelin A and B receptors was dramatically inhibited by CPU0213. Conclusion: Taken together, these results suggest that this Nox4-dependenet O2- production is critical for the apoptosis of HK-2 cells in high glucose. Endothelin receptor antagonist CPU0213 has an anti-apoptosis role through Nox4-dependent O2-.production, which address the nephroprotective role of CPU0213 in diabetic nephropathy.

  2. Enhanced anticancer effect of fabricated gallic acid/CdS on the rGO nanosheets on human glomerular mesangial (IP15) and epithelial proximal (HK2) kidney cell lines - Cytotoxicity investigations.

    Science.gov (United States)

    Peng, Wei; Luo, Pengcheng; Gui, Dingwen; Jiang, Weidong; Wu, Haixia; Zhang, Jie

    2018-01-01

    In spite of the technological innovation in the biomedical science, cancer remains a critical disease. In this study, we designed a gallic acid/cadmium sulfide (GA/CdS) nanocomposite fabricated on the reduced graphene oxide (GA/CdS-rGO) nanosheets for the treatment system of human kidney cancer cells. The GA/CdS-rGO nanosheets have been prepared using gallic acid as a reducing agent. The characterization of nanocomposites was studied using UV-Vis spectroscope, FT-IR, XRD, SEM and TEM. The microscopic images showed the spherical shape and nano-scaled CdS nanoparticles on the sheet like rGO nanomaterials. These structural and morphology investigations show that excellent properties of as-prepared GA/CdS-rGO has ability to treat the human glomerular mesangial (IP15) cancer cells at 50μg/ml as an IC 50 value, without affecting the epithelial proximal (HK-2) normal cells. In vitro cytotoxicity results showed that the variability of toxic effects after CdS exposure was strongly associated to the cellular Cd content. Release of Cd 2+ from nanocomposites depended to solubility and particle degradation of CdS nanoparticles were considered to be the main cause of these cytotoxicity. The in vitro analysis results indicated that heterogeneity of Cd and gallic acid toxicity that was highly dependent on the physico-chemical properties of the nanocomposites. The cytotoxicity results suggested that the prepared nanomaterials were toxic and inhibitory efficiency to human kidney cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. hköajoneuvojen akusto ja kestoikä

    OpenAIRE

    Niemi, Miro

    2016-01-01

    Tämän opinnäytetyön aiheena on sähköautojen akustojen kestävyys ja kapasiteetin lasku.Työn tarkoituksena on selvittää, miten sähköautojen akkukapasiteetti laskee ja mitkä eri tekijät siihen vaikuttavat.Työ on toteutettu kirjallisuusselvityksenä tutkimalla aihetta käsitteleviä internetlähteitä ja kirjallisuutta. Työssä on käsitelty yleisimmät sähköautoissa käytettävät akkutyypit ja niiden rakenne sekä tarkasteltu yleisesti sähköautojen ja akkujen toimintaa. Samalla on myös selvitetty, mit...

  4. Urinary Excretion of Tetrodotoxin Modeled in a Porcine Renal Proximal Tubule Epithelial Cell Line, LLC-PK1

    Directory of Open Access Journals (Sweden)

    Takuya Matsumoto

    2017-07-01

    Full Text Available This study examined the urinary excretion of tetrodotoxin (TTX modeled in a porcine renal proximal tubule epithelial cell line, LLC-PK1. Time course profiles of TTX excretion and reabsorption across the cell monolayers at 37 °C showed that the amount of TTX transported increased linearly for 60 min. However, at 4 °C, the amount of TTX transported was approximately 20% of the value at 37 °C. These results indicate that TTX transport is both a transcellular and carrier-mediated process. Using a transport inhibition assay in which cell monolayers were incubated with 50 µM TTX and 5 mM of a transport inhibitor at 37 °C for 30 min, urinary excretion was significantly reduced by probenecid, tetraethylammonium (TEA, l-carnitine, and cimetidine, slightly reduced by p-aminohippuric acid (PAH, and unaffected by 1-methyl-4-phenylpyridinium (MPP+, oxaliplatin, and cefalexin. Renal reabsorption was significantly reduced by PAH, but was unaffected by probenecid, TEA and l-carnitine. These findings indicate that TTX is primarily excreted by organic cation transporters (OCTs and organic cation/carnitine transporters (OCTNs, partially transported by organic anion transporters (OATs and multidrug resistance-associated proteins (MRPs, and negligibly transported by multidrug and toxic compound extrusion transporters (MATEs.

  5. ALA/LA ameliorates glucose toxicity on HK-2 cells by attenuating oxidative stress and apoptosis through the ROS/p38/TGF-β1 pathway.

    Science.gov (United States)

    Jiang, Mingxia; Zhang, Haifen; Zhai, Lijie; Ye, Bianliang; Cheng, Yin; Zhai, Chengkai

    2017-11-16

    Growing evidence indicates that oxidative stress (OS) plays a pivotal role in Diabetic nephropathy (DN). In a previous study we demonstrated that ALA/LA protected HK-2 cells against high glucose-induced cytotoxicity. So we aimed to establish the glucose injury model of HK-2 cells and investigate the beneficial effects of ALA/LA on high glucose-induced excessive production of TGF-β1 and the possible mechanisms mediating the effects. The expression of OS markers in high glucose-induced HK-2 cells treated with ALA/LA., including the antioxidant enzymes and reactive oxygen species (ROS) production, as well as the apoptosis rate were assayed by ELISA and flow cytometry. The p38/transforming growth factor β 1 (TGF-β 1 ) signal pathway were measured by real-time RT-PCR and western blot. The modeling condition of glucose toxicity on HK-2 cells was at the glucose concentration of 40.9 mM. ALA/LA can significantly increase the activities of antioxidant enzymes and decrease ROS production stimulated by high glucose. The study also found that ALA/LA caused a decrease in the apoptosis rate and TGF-β 1 level of HK-2 cells under high glucose stress through the ROS/p38 pathway. ALA/LA exerts protective effects in vitro through inhibition of ROS generation, down regulation of the activation of the p38MAPK pathway and the expression of TGF-β 1 in HK-2 cells.

  6. Active lithium transport by rat renal proximal tubule: a micropuncture study

    DEFF Research Database (Denmark)

    Leyssac, P P; Frederiksen, O; Holstein-Rathlou, N H

    1994-01-01

    We tested the hypothesis that proximal tubular Li+ reabsorption is due to passive transport. Clearances of [14C]inulin (CIn) and Li+ (CLi), proximal transepithelial electrical potential difference (PD), and tubular fluid-to-plasma Li+ concentration ratios [(TF/P)Li] were measured in anesthetized ...

  7. Bone Morphogenetic Protein (BMP-7 expression is decreased in human hypertensive nephrosclerosis

    Directory of Open Access Journals (Sweden)

    Cohen Clemens D

    2010-11-01

    Full Text Available Abstract Background Bone Morphogenetic Protein (BMP-7 is protective in different animal models of acute and chronic kidney disease. Its role in human kidneys, and in particular hypertensive nephrosclerosis, has thus far not been described. Methods BMP-7 mRNA was quantified using real-time PCR and localised by immunostaining in tissue samples from normal and nephrosclerotic human kidneys. The impact of angiotensin (AT-II and the AT-II receptor antagonist telmisartan on BMP-7 mRNA levels and phosphorylated Smad 1/5/8 (pSmad 1/5/8 expression was quantified in proximal tubular cells (HK-2. Functional characteristics of BMP-7 were evaluated by testing its influence on TGF-β induced epithelial-to-mesenchymal transition (EMT, expression of TGF-β receptor type I (TGF-βRI and phosphorylated Smad 2 (pSmad 2 as well as on TNF-α induced apoptosis of proximal tubular cells. Results BMP-7 was predominantly found in the epithelia of the distal tubule and the collecting duct and was less abundant in proximal tubular cells. In sclerotic kidneys, BMP-7 was significantly decreased as demonstrated by real-time PCR and immunostaining. AT-II stimulation in HK-2 cells led to a significant decrease of BMP-7 and pSmad 1/5/8, which was partially ameliorated upon co-incubation with telmisartan. Only high concentrations of BMP-7 (100 ng/ml were able to reverse TNF-α-induced apoptosis and TGF-β-induced EMT in human proximal tubule cells possibly due to a decreased expression of TGF-βRI. In addition, BMP-7 was able to reverse TGF-β-induced phosphorylation of Smad 2. Conclusions The findings suggest a protective role for BMP-7 by counteracting the TGF-β and TNF-α-induced negative effects. The reduced expression of BMP-7 in patients with hypertensive nephrosclerosis may imply loss of protection and regenerative potential necessary to counter the disease.

  8. Changes in gene expression in human renal proximal tubule cells exposed to low concentrations of S-(1,2-dichlorovinyl)-L-cysteine, a metabolite of trichloroethylene

    International Nuclear Information System (INIS)

    Lock, Edward A.; Barth, Jeremy L.; Argraves, Scott W.; Schnellmann, Rick G.

    2006-01-01

    Epidemiology studies suggest that there may be a weak association between high level exposure to trichloroethylene (TCE) and renal tubule cell carcinoma. Laboratory animal studies have shown an increased incidence of renal tubule carcinoma in male rats but not mice. TCE can undergo metabolism via glutathione (GSH) conjugation to form metabolites that are known to be nephrotoxic. The GSH conjugate, S-(1,2-dichlorovinyl)glutathione (DCVG), is processed further to the cysteine conjugate, S-(1,2-dichlorovinyl)-L-cysteine (DCVC), which is the penultimate nephrotoxic species. We have cultured human renal tubule cells (HRPTC) in serum-free medium under a variety of different culture conditions and observed growth, respiratory control and glucose transport over a 20 day period in medium containing low glucose. Cell death was time- and concentration-dependent, with the EC 5 for DCVG being about 3 μM and for DCVC about 7.5 μM over 10 days. Exposure of HRPTC to sub-cytotoxic doses of DCVC (0.1 μM and 1 μM for 10 days) led to a small number of changes in gene expression, as determined by transcript profiling with Affymetrix human genome chips. Using the criterion of a mean 2-fold change over control for the four samples examined, 3 genes at 0.1 μM DCVC increased, namely, adenosine kinase, zinc finger protein X-linked and an enzyme with lyase activity. At 1 μM DCVC, two genes showed a >2-fold decrease, N-acetyltransferase 8 and complement factor H. At a lower stringency (1.5-fold change), a total of 63 probe sets were altered at 0.1 μM DCVC and 45 at 1 μM DCVC. Genes associated with stress, apoptosis, cell proliferation and repair and DCVC metabolism were altered, as were a small number of genes that did not appear to be associated with the known mode of action of DCVC. Some of these genes may serve as molecular markers of TCE exposure and effects in the human kidney

  9. Unique role of NADPH oxidase 5 in oxidative stress in human renal proximal tubule cells

    Directory of Open Access Journals (Sweden)

    Peiying Yu

    2014-01-01

    Full Text Available NADPH oxidases are the major sources of reactive oxygen species in cardiovascular, neural, and kidney cells. The NADPH oxidase 5 (NOX5 gene is present in humans but not rodents. Because Nox isoforms in renal proximal tubules (RPTs are involved in the pathogenesis of hypertension, we tested the hypothesis that NOX5 is differentially expressed in RPT cells from normotensive (NT and hypertensive subjects (HT. We found that NOX5 mRNA, total NOX5 protein, and apical membrane NOX5 protein were 4.2±0.7-fold, 5.2±0.7-fold, and 2.8±0.5-fold greater in HT than NT. Basal total NADPH oxidase activity was 4.5±0.2-fold and basal NOX5 activity in NOX5 immunoprecipitates was 6.2±0.2-fold greater in HT than NT (P=<0.001, n=6–14/group. Ionomycin increased total NOX and NOX5 activities in RPT cells from HT (P<0.01, n=4, ANOVA, effects that were abrogated by pre-treatment of the RPT cells with diphenylene-iodonium or superoxide dismutase. Silencing NOX5 using NOX5-siRNA decreased NADPH oxidase activity (−45.1±3.2% vs. mock-siRNA, n=6–8 in HT. D1-like receptor stimulation decreased NADPH oxidase activity to a greater extent in NT (−32.5±1.8% than HT (−14.8±1.8. In contrast to the marked increase in expression and activity of NOX5 in HT, NOX1 mRNA and protein were minimally increased in HT, relative to NT; total NOX2 and NOX4 proteins were not different between HT and NT, while the increase in apical RPT cell membrane NOX1, NOX2, and NOX4 proteins in HT, relative to NT, was much less than those observed with NOX5. Thus, we demonstrate, for the first time, that NOX5 is expressed in human RPT cells and to greater extent than the other Nox isoforms in HT than NT. We suggest that the increased expression of NOX5, which may be responsible for the increased oxidative stress in RPT cells in human essential hypertension, is caused, in part, by a defective renal dopaminergic system.

  10. Space-environmental tolerances in a cyanobacterium, Nostoc sp. HK-01

    Science.gov (United States)

    Tomita-Yokotani, Kaori; Yokobori, Shin-ichi; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Ajioka, Reiko; Yamagishi, Akihiko; Inoue, Kotomi

    2016-07-01

    We have been investigating the tolerances to space-environments of a cyanobacterium, Nostoc sp. HK-01 (hereafter referred to as HK-01). Dry colonies of HK-01 had high tolerance to dry conditions, but more detailed information about tolerance to high-temperature, UV, gamma-ray and heavy particle beams were not deeply investigated. The obtained dry colonies of HK-01 after exposure to each of the conditions described above were investigated. In all of the tested colonies of HK-01 after exposure, all or some of the cells in the colonies were alive. One of the purposes of space agriculture is growing plants on Mars. In the early stages, of our research, cyanobacteria are introduced on Mars to promote the oxidation of the atmosphere and the formation of soil from Mars's regolith. HK-01 will contribute to each of these factors in the future.

  11. Megalin-mediated specific uptake of chitosan/siRNA nanoparticles in mouse kidney proximal tubule epithelial cells enables AQP1 gene silencing.

    Science.gov (United States)

    Gao, Shan; Hein, San; Dagnæs-Hansen, Frederik; Weyer, Kathrin; Yang, Chuanxu; Nielsen, Rikke; Christensen, Erik I; Fenton, Robert A; Kjems, Jørgen

    2014-01-01

    RNAi-based strategies provide a great therapeutic potential for treatment of various human diseases including kidney disorders, but face the challenge of in vivo delivery and specific targeting. The chitosan delivery system has previously been shown to target siRNA specifically to the kidneys in mice when administered intravenously. Here we confirm by 2D and 3D bioimaging that chitosan formulated siRNA is retained in the kidney for more than 48 hours where it accumulates in proximal tubule epithelial cells (PTECs), a process that was strongly dependent on the molecular weight of chitosan. Chitosan/siRNA nanoparticles, administered to chimeric mice with conditional knockout of the megalin gene, distributed almost exclusively in cells that expressed megalin, implying that the chitosan/siRNA particle uptake was mediated by a megalin-dependent endocytotic pathway. Knockdown of the water channel aquaporin 1 (AQP1) by up to 50% in PTECs was achieved utilizing the systemic i.v. delivery of chitosan/AQP1 siRNA in mice. In conclusion, specific targeting PTECs with the chitosan nanoparticle system may prove to be a useful strategy for knockdown of specific genes in PTECs, and provides a potential therapeutic strategy for treating various kidney diseases.

  12. Sodium pumps in the Malpighian tubule of Rhodnius sp.

    Directory of Open Access Journals (Sweden)

    CARUSO-NEVES CELSO

    2000-01-01

    Full Text Available Malpighian tubule of Rhodnius sp. express two sodium pumps: the classical ouabain-sensitive (Na+ + K+ATPase and an ouabain-insensitive, furosemide-sensitive Na+-ATPase. In insects, 5-hydroxitryptamine is a diuretic hormone released during meals. It inhibits the (Na+ + K+ATPase and Na+ -ATPase activities indicating that these enzymes are involved in fluid secretion. Furthermore, in Rhodnius neglectus, proximal cells of Malpighian tubule exposed to hyperosmotic medium, regulate their volume through a mechanism called regulatory volume increase. This regulatory response involves inhibition of the (Na+ + K+ATPase activity that could lead to accumulation of active osmotic solute inside the cell, influx of water and return to the normal cell volume. Adenosine, a compound produced in stress conditions, also inhibits the (Na+ + K+ATPase activity. Taken together these data indicate that (Na+ + K+ATPase is a target of the regulatory mechanisms of water and ions transport responsible for homeostasis in Rhodnius sp.

  13. hköisen rakennusluvan hakeminen ja hyvä tiedonhallintatapa

    OpenAIRE

    Korpela, Marika

    2012-01-01

    Opinnäytetyön aiheena oli sähköisen rakennusluvan hakeminen ja hyvä tiedonhallintatapa. Työn toimeksiantaja oli Salon kaupunki, rakennusvalvontayksikkö. Työ toteutettiin tutkimalla sähköistä asiointia käsitteleviä lakeja. Empiiriosassa teoriaa sovellettiin Salon kaupungin rakennusvalvontayksikön toimintaan sekä annettiin ohjeita sähköisen asioinnin vaatimuksista. Tärkein asian käsittelyyn liittyvä lainsäädäntö on laki sähköisestä asioinnista viranomaistoiminnassa (SAVL 13/2003). Lisäksi h...

  14. The tripartite capsid gene of Salmonella phage Gifsy-2 yields a capsid assembly pathway engaging features from HK97 and λ

    International Nuclear Information System (INIS)

    Effantin, Gregory; Figueroa-Bossi, Nara; Schoehn, Guy; Bossi, Lionello; Conway, James F.

    2010-01-01

    Phage Gifsy-2, a lambdoid phage infecting Salmonella, has an unusually large composite gene coding for its major capsid protein (mcp) at the C-terminal end, a ClpP-like protease at the N-terminus, and a ∼ 200 residue central domain of unknown function but which may have a scaffolding role. This combination of functions on a single coding region is more extensive than those observed in other phages such as HK97 (scaffold-capsid fusion) and λ (protease-scaffold fusion). To study the structural phenotype of the unique Gifsy-2 capsid gene, we have purified Gifsy-2 particles and visualized capsids and procapsids by cryoelectron microscopy, determining structures to resolutions up to 12 A. The capsids have lambdoid T = 7 geometry and are well modeled with the atomic structures of HK97 mcp and phage λ gpD decoration protein. Thus, the unique Gifsy-2 capsid protein gene yields a capsid maturation pathway engaging features from both phages HK97 and λ.

  15. Evolution of space food in Nostoc sp. HK-01

    Science.gov (United States)

    Tomita-Yokotani, Kaori; Yamashita, Masamichi; Hashimoto, Hirofumi; Sato, Seigo; Kimura, Yasuko; Katoh, Hiroshi; Arai, Mayumi

    2012-07-01

    Habitation in outer space is one of our challenges. We have been studying future space agriculture to provide food and oxygen for the habitation area in the space environment, on Mars. A cyanobacteria, Nostoc sp. HK-01, has high several outer space environmental tolerance. We have already confirmed that Nostoc sp.HK-01 had an ability to grow for over several years on the Martian regolith simulant in a laboratory experiment. Nostoc sp HK-01 would have high contribution to change the atmosphere in Mars as a photosynthetic creature. In outer environment, all of materials have to circulate for all of creature living in artificial eco-systems on Mars. This material has several functions as the utilization in space agriculture. Here, we are proposing using them as a food after its growing on Mars. We are trying to determine the best conditions and evolution for space food using Nostoc sp.HK-01 and studying the proposal of utilization of cyanobacteria, Nostoc sp HK-01, for the variation of meal as space agriculture.

  16. hkösuunnittelu osana suunnitteluprojektia

    OpenAIRE

    Grönroos, Roope

    2016-01-01

    Insinöörityö tehtiin Sweco Industry Oy:n automaatio-osastolle. Työssä tutkittiin, kuinka teollisuuden sähkösuunnittelu liittyy suunnitteluprojekteissa muihin suunnittelualoihin isomman suunnittelukonsernin näkökulmasta. Alussa perehdytään muihin suunnittelualoihin ja siihen, kuinka ne ovat sidoksissa teollisuuden sähkösuunnitteluun. Alussa käydään läpi suunnitteluprojektin eri vaiheita ja mitä niihin sisältyy. Työtä varten haastateltiin eri suunnittelualojen kokeneita ammattil...

  17. Utilization of a terrestrial cyanobacterium, Nostoc sp. HK-01, for space habitation

    Science.gov (United States)

    Kimura, Shunta; Tomita-Yokotani, Kaori; Arai, Mayumi; Yamashita, Masamichi; Katoh, Hiroshi; Ajioka, Reiko; Inoue, Kotomi

    2016-07-01

    A terrestrial cyanobacterium, Nostoc sp. HK-01 (hereafter HK-01), has several useful abilities for space habitation; photosynthesis, nitrogen fixation, and space environmental tolerances to vacuum, UV, gamma-ray, heavy particle beam, low and high temperature. Space environmental tolerances are important for transportation to Mars. HK-01 can grow on Martian regolith simulant (MRS) in vitro. Furthermore, HK-01 is useful as food. HK-01 may be utilized as oxygen supply, soil formation and food material for bio-chemical circulation in closed bio-ecosystems, including space habitation such as Mars. HK-01 was adopted as a biological material for the "TANPOPO" mission (JAXA et al.,), because of their high environmental tolerances. The "TANPOPO" mission is performing the space exposure experiments on the Japan Experimental Module (JEM) of the International Space Station (ISS). The results of these experiments will show the ability of HK-01 to survive in space.

  18. A bioartificial renal tubule device embedding human renal stem/progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anna Giovanna Sciancalepore

    Full Text Available We present a bio-inspired renal microdevice that resembles the in vivo structure of a kidney proximal tubule. For the first time, a population of tubular adult renal stem/progenitor cells (ARPCs was embedded into a microsystem to create a bioengineered renal tubule. These cells have both multipotent differentiation abilities and an extraordinary capacity for injured renal cell regeneration. Therefore, ARPCs may be considered a promising tool for promoting regenerative processes in the kidney to treat acute and chronic renal injury. Here ARPCs were grown to confluence and exposed to a laminar fluid shear stress into the chip, in order to induce a functional cell polarization. Exposing ARPCs to fluid shear stress in the chip led the aquaporin-2 transporter to localize at their apical region and the Na(+K(+ATPase pump at their basolateral portion, in contrast to statically cultured ARPCs. A recovery of urea and creatinine of (20±5% and (13±5%, respectively, was obtained by the device. The microengineered biochip here-proposed might be an innovative "lab-on-a-chip" platform to investigate in vitro ARPCs behaviour or to test drugs for therapeutic and toxicological responses.

  19. Regulation of MRP2-mediated transport in shark rectal salt gland tubules.

    NARCIS (Netherlands)

    Miller, D.S.; Masereeuw, R.; Karnaky Jr, K.J.

    2002-01-01

    We examined endothelin-1 (ET-1) regulation of the xenobiotic efflux pump, multidrug resistance-associated protein isoform 2 (MRP2), in intact dogfish shark rectal salt gland tubules using a fluorescent substrate sulforhodamine 101 and confocal microscopy. Subnanomolar to nanomolar concentrations of

  20. Autosähköinsinöörikoulutuksen kehittäminen

    OpenAIRE

    Kovanen, Pasi

    2017-01-01

    Tässä opinnäytetyössä analysoidaan ja verrataan Metropolian ajoneuvotekniikan tutkinto-ohjelman autosähkötekniikan opetussuunnitelmaa kotimaisten ja ulkomaisten korkeakoulujen opetussuunnitelmiin. Metropolian autosähkötekniikan opetussuunnitelmassa on vertailluista kohteista eniten autosähköteknistä opetusta. Ulkomaisissa korkeakouluissa suoritetuttujen teemahaastattelujen avulla analysoidaan sidosryhmien käyttöä opetusmateriaalin lähteenä, sekä ajoneuvoteollisuuden vaikutusta opetussuun...

  1. Protein kinase C-mediated ATP stimulation of Na(+)-ATPase activity in LLC-PK1 cells involves a P2Y2 and/or P2Y4 receptor.

    Science.gov (United States)

    Wengert, M; Ribeiro, M C; Abreu, T P; Coutinho-Silva, R; Leão-Ferreira, L R; Pinheiro, A A S; Caruso-Neves, C

    2013-07-15

    ATP-activated P2Y receptors play an important role in renal sodium excretion. The aim of this study was to evaluate the modulation of ATPase-driven sodium reabsorption in the proximal tubule by ATP or adenosine (Ado). LLC-PK1 cells, a model of porcine proximal tubule cells, were used. ATP (10(-6)M) or Ado (10(-6)M) specifically stimulated Na(+)-ATPase activity without any changes in (Na(+)+K(+))-ATPase activity. Our results show that the Ado effect is mediated by its conversion to ATP. Furthermore, it was observed that the effect of ATP was mimicked by UTP, ATPγS and 2-thio-UTP, an agonist of P2Y2 and P2Y4 receptors. In addition, ATP-stimulated Na(+)-ATPase activity involves protein kinase C (PKC). Our results indicate that ATP-induced stimulation of proximal tubule Na(+)-ATPase activity is mediated by a PKC-dependent P2Y2 and/or P2Y4 pathway. These findings provide new perspectives on the role of the effect of P2Y-mediated extracellular ATP on renal sodium handling. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. hköinen palkkahallinto yrityksen, tilitoimiston ja palkanlaskijan kannalta

    OpenAIRE

    Majava, Tero

    2010-01-01

    Opinnäytetyön tavoitteena oli tutkia sähköisen palkkahallinnon vaikutuksia ja näkökulmia yrityksen, tilitoimiston ja palkanlaskijan kannalta verrattuna perinteiseen palkkahallintoon. Tarkoituksena oli kartoittaa sähköisen palkkahallinnon hyödyt ja haitat kaikista kolmesta eri näkökulmasta ja sitä, onko kannattavaa siirtyä sähköisen palkkahallinnon pariin. Tutkimus on tehty kvalitatiivista tutkimusmenetelmää käyttäen, pohjautuen kirjoituspöytätyöhön, tutkien ja analysoiden aiheeseen liitty...

  3. Locally formed dopamine inhibits Na+-K+-ATPase activity in rat renal cortical tubule cells

    International Nuclear Information System (INIS)

    Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J.

    1988-01-01

    Dopamine, generated locally from L-dopa, inhibits Na + -K + -ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na + -K + -ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate (Qo 2 ) and 86 Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive Qo 2 or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive Qo 2 in a concentration-dependent manner, with half-maximal inhibition (K 0.5 ) of 5 x 10 -7 M and a maximal inhibition of 14.1 ± 1.5% at 10 -4 M. L-Dopa also blunted the nystatin-stimulated Qo 2 in a concentration-dependent manner, indicating the L-dopa directly inhibits Na + -K + -ATPase activity and not sodium entry. Ouabain-sensitive 86 Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive Qo 2 and 86 Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive Qo 2 at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na + -K + -ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner

  4. Efficacy of a novel chelator BPCBG for removing uranium and protecting against uranium-induced renal cell damage in rats and HK-2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Yizhong; Wang, Dan [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Li, Zhiming [Department of Chemistry, Fudan University, Shanghai 200433 (China); Hu, Yuxing; Xu, Aihong [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Wang, Quanrui [Department of Chemistry, Fudan University, Shanghai 200433 (China); Shao, Chunlin [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Chen, Honghong, E-mail: hhchen@shmu.edu.cn [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China)

    2013-05-15

    Chelation therapy is a known effective method to increase the excretion of U(VI) from the body. Until now, no any uranium chelator has been approved for emergency medical use worldwide. The present study aimed to evaluate the efficacy of new ligand BPCBG containing two catechol groups and two aminocarboxylic acid groups in decorporation of U(VI) and protection against acute U(VI) nephrotoxicity in rats, and further explored the detoxification mechanism of BPCBG for U(VI)-induced nephrotoxicity in HK-2 cells with comparison to DTPA-CaNa{sub 3}. Chelating agents were administered at various times before or after injections of U(VI) in rats. The U(VI) levels in urine, kidneys and femurs were measured 24 h after U(VI) injections. Histopathological changes in the kidney and serum urea and creatinine and urine protein were examined. After treatment of U(VI)-exposed HK-2 cells with chelating agent, the intracellular U(VI) contents, formation of micronuclei, lactate dehydrogenase (LDH) activity and production of reactive oxygen species (ROS) were assessed. It was found that prompt, advanced or delayed injections of BPCBG effectively increased 24 h-urinary U(VI) excretion and decreased the levels of U(VI) in kidney and bone. Meanwhile, BPCBG injection obviously reduced the severity of the U(VI)-induced histological alterations in the kidney, which was in parallel with the amelioration noted in serum indicators, urea and creatinine, and urine protein of U(VI) nephrotoxicity. In U(VI)-exposed HK-2 cells, immediate and delayed treatment with BPCBG significantly decreased the formation of micronuclei and LDH release by inhibiting the cellular U(VI) intake, promoting the intracellular U(VI) release and inhibiting the production of intracellular ROS. Our data suggest that BPCBG is a novel bi-functional U(VI) decorporation agent with a better efficacy than DTPA-CaNa{sub 3}. - Highlights: ► BPCBG accelerated the urine U(VI) excretion and reduced the tissues U(VI) in rats.

  5. Kidney-differentiated cells derived from Lowe Syndrome patient's iPSCs show ciliogenesis defects and Six2 retention at the Golgi complex.

    Directory of Open Access Journals (Sweden)

    Wen-Chieh Hsieh

    Full Text Available Lowe syndrome is an X-linked condition characterized by congenital cataracts, neurological abnormalities and kidney malfunction. This lethal disease is caused by mutations in the OCRL1 gene, which encodes for the phosphatidylinositol 5-phosphatase Ocrl1. While in the past decade we witnessed substantial progress in the identification and characterization of LS patient cellular phenotypes, many of these studies have been performed in knocked-down cell lines or patient's cells from accessible cell types such as skin fibroblasts, and not from the organs affected. This is partially due to the limited accessibility of patient cells from eyes, brain and kidneys. Here we report the preparation of induced pluripotent stem cells (iPSCs from patient skin fibroblasts and their reprogramming into kidney cells. These reprogrammed kidney cells displayed primary cilia assembly defects similar to those described previously in cell lines. Additionally, the transcription factor and cap mesenchyme marker Six2 was substantially retained in the Golgi complex and the functional nuclear-localized fraction was reduced. These results were confirmed using different batches of differentiated cells from different iPSC colonies and by the use of the human proximal tubule kidney cell line HK2. Indeed, OCRL1 KO led to both ciliogenesis defects and Six2 retention in the Golgi complex. In agreement with Six2's role in the suppression of ductal kidney lineages, cells from this pedigree were over-represented among patient kidney-reprogrammed cells. We speculate that this diminished efficacy to produce cap mesenchyme cells would cause LS patients to have difficulties in replenishing senescent or damaged cells derived from this lineage, particularly proximal tubule cells, leading to pathological scenarios such as tubular atrophy.

  6. Cytotoxicity of S-conjugates of the sevoflurane degradation product fluoromethyl-2,2-difluoro-1-(trifluoromethyl) vinyl ether (Compound A) in a human proximal tubular cell line

    International Nuclear Information System (INIS)

    Altuntas, T. Gul; Zager, Richard A.; Kharasch, Evan D.

    2003-01-01

    Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) is a fluorinated alkene formed by degradation of the volatile anesthetic sevoflurane in anesthesia machines. FDVE is nephrotoxic in rats but not humans. Rat FDVE nephrotoxicity is attributed to FDVE glutathione conjugation and bioactivation of subsequent FDVE-cysteine S-conjugates, in part by renal β-lyase. Although FDVE conjugation and metabolism occur in both rats and humans, the mechanism for selective toxicity in rats and lack of effect in humans is incompletely elucidated. This investigation measured FDVE S-conjugate cytotoxicity in cultured human proximal tubular HK-2 cells, and compared this with known cytotoxic S-conjugates. HK-2 cells were incubated with FDVE and its GSH, cysteine S-mercapturic acid, cysteine S-sulfoxide, and mercapturic acid sulfoxide conjugates (0.1-2.7 mM) for 24 h. Cytotoxicity was determined by lactate dehydrogenase (LDH) release, total LDH, and the ability of viable cells to reduce a tetrazolium-based compound (MTT). FDVE was cytotoxic only at concentrations ≥0.9 mM. No increase in LDH release was observed with either FDVE-GSH conjugate. The FDVE-cysteine conjugates S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine (DFEC) and (Z)-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-FFVC) caused significant differences in LDH release and MTT reduction only at 2.7 mM; (Z)-FFVC was slightly more cytotoxic. Both S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine sulfoxide (DFEC-SO) and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine sulfoxide ((Z)-N-Ac-FFVC-SO) caused slightly greater changes in LDH release or total LDH than the corresponding equimolar DFEC and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-N-Ac-FFVC) conjugates. In contrast to FDVE S-conjugates, S-(1,2-dichlorovinyl)-L-cysteine was markedly cytotoxic, at concentrations as low as 0

  7. Proximal Tubular Cannabinoid-1 Receptor Regulates Obesity-Induced CKD.

    Science.gov (United States)

    Udi, Shiran; Hinden, Liad; Earley, Brian; Drori, Adi; Reuveni, Noa; Hadar, Rivka; Cinar, Resat; Nemirovski, Alina; Tam, Joseph

    2017-12-01

    Obesity-related structural and functional changes in the kidney develop early in the course of obesity and occur independently of hypertension, diabetes, and dyslipidemia. Activating the renal cannabinoid-1 receptor (CB 1 R) induces nephropathy, whereas CB 1 R blockade improves kidney function. Whether these effects are mediated via a specific cell type within the kidney remains unknown. Here, we show that specific deletion of CB 1 R in the renal proximal tubule cells did not protect the mice from obesity, but markedly attenuated the obesity-induced lipid accumulation in the kidney and renal dysfunction, injury, inflammation, and fibrosis. These effects associated with increased activation of liver kinase B1 and the energy sensor AMP-activated protein kinase, as well as enhanced fatty acid β -oxidation. Collectively, these findings indicate that renal proximal tubule cell CB 1 R contributes to the pathogenesis of obesity-induced renal lipotoxicity and nephropathy by regulating the liver kinase B1/AMP-activated protein kinase signaling pathway. Copyright © 2017 by the American Society of Nephrology.

  8. Topotactic dehydration of the lamellar oxide HK2Ti5NbO14 x H2O: the oxide K4Ti10Nb2O27

    International Nuclear Information System (INIS)

    Grandin, A.; Borel, M.M.; Hervieu, M.; Raveau, B.

    1987-01-01

    The lamellar oxide HK 2 Ti 5 NbO 14 x H 2 O can be topotactically dehydrated to K 4 Ti 10 Nb 2 O 27 . Electron diffraction and X-ray diffraction studies of this phase lead to a monoclinic cell with the parameters a = 17.005, b = 3.78, c = 9.01 A and β 92.14 0 . Diffusion streaks on the electron diffraction patterns indicate disorder whereas the existence of two sets of lattices on the same crystal give evidence of the topotactic character of the reaction. A structural model is proposed for K 4 Ti 10 Nb 2 O 27 , which corresponds to the intergrowth of K 3 TiNbO 14 layers with the K 2 Ti 6 O 13 tunnel structure. The possibility of formation of various intergrowths such as (KTi 5 NbO 13 )/sub n/ (HK 2 Ti 5 NbO 14 )/sub n/' is suggested

  9. Host range, immunity and antigenic properties of lambdoid coliphage HK97.

    Science.gov (United States)

    Dhillon, E K; Dhillon, T S; Lai, A N; Linn, S

    1980-09-01

    Temperate coliphage HK97 was isolated from pig dung. Although HK97 is antigenically unrelated to coliphage lambda, it has similar morphology, host range and immunity properties, and can recombine with it.

  10. Cystogenesis and elongated primary cilia in Tsc1-deficient distal convoluted tubules.

    Science.gov (United States)

    Armour, Eric A; Carson, Robert P; Ess, Kevin C

    2012-08-15

    Tuberous sclerosis complex (TSC) is a multiorgan hamartomatous disease caused by loss of function mutations of either the TSC1 or TSC2 genes. Neurological symptoms of TSC predominate in younger patients, but renal pathologies are a serious aspect of the disease in older children and adults. To study TSC pathogenesis in the kidney, we inactivated the mouse Tsc1 gene in the distal convoluted tubules (DCT). At young ages, Tsc1 conditional knockout (CKO) mice have enlarged kidneys and mild cystogenesis with increased mammalian target of rapamycin complex (mTORC)1 but decreased mTORC2 signaling. Treatment with the mTORC1 inhibitor rapamycin reduces kidney size and cystogenesis. Rapamycin withdrawal led to massive cystogenesis involving both distal as well as proximal tubules. To assess the contribution of decreased mTORC2 signaling in kidney pathogenesis, we also generated Rictor CKO mice. These animals did not have any detectable kidney pathology. Finally, we examined primary cilia in the DCT. Cilia were longer in Tsc1 CKO mice, and rapamycin treatment returned cilia length to normal. Rictor CKO mice had normal cilia in the DCT. Overall, our findings suggest that loss of the Tsc1 gene in the DCT is sufficient for renal cystogenesis. This cytogenesis appears to be mTORC1 but not mTORC2 dependent. Intriguingly, the mechanism may be cell autonomous as well as non-cell autonomous and possibly involves the length and function of primary cilia.

  11. Cystogenesis and elongated primary cilia in Tsc1-deficient distal convoluted tubules

    Science.gov (United States)

    Armour, Eric A.; Carson, Robert P.

    2012-01-01

    Tuberous sclerosis complex (TSC) is a multiorgan hamartomatous disease caused by loss of function mutations of either the TSC1 or TSC2 genes. Neurological symptoms of TSC predominate in younger patients, but renal pathologies are a serious aspect of the disease in older children and adults. To study TSC pathogenesis in the kidney, we inactivated the mouse Tsc1 gene in the distal convoluted tubules (DCT). At young ages, Tsc1 conditional knockout (CKO) mice have enlarged kidneys and mild cystogenesis with increased mammalian target of rapamycin complex (mTORC)1 but decreased mTORC2 signaling. Treatment with the mTORC1 inhibitor rapamycin reduces kidney size and cystogenesis. Rapamycin withdrawal led to massive cystogenesis involving both distal as well as proximal tubules. To assess the contribution of decreased mTORC2 signaling in kidney pathogenesis, we also generated Rictor CKO mice. These animals did not have any detectable kidney pathology. Finally, we examined primary cilia in the DCT. Cilia were longer in Tsc1 CKO mice, and rapamycin treatment returned cilia length to normal. Rictor CKO mice had normal cilia in the DCT. Overall, our findings suggest that loss of the Tsc1 gene in the DCT is sufficient for renal cystogenesis. This cytogenesis appears to be mTORC1 but not mTORC2 dependent. Intriguingly, the mechanism may be cell autonomous as well as non-cell autonomous and possibly involves the length and function of primary cilia. PMID:22674026

  12. Characterization of biotransformation enzyme activities in primary rat proximal tubular cells

    NARCIS (Netherlands)

    Schaaf, G.; de Groene, E.M.; Maas, R.; Commandeur, J.N.M.; Fink-Gremmels, J.

    2001-01-01

    The proximal tubule is a frequent target for nephrotoxic compounds due to it's ability to transport and accumulate xenobiotics and their metabolites, as well as by the presence of an organ-selective set of biotransformation enzymes. The aim of the present study was to characterize the activities of

  13. Ginsenoside 20(S)-Rg3 Inhibits the Warburg Effect Via Modulating DNMT3A/ MiR-532-3p/HK2 Pathway in Ovarian Cancer Cells.

    Science.gov (United States)

    Zhou, Yuanyuan; Zheng, Xia; Lu, Jiaojiao; Chen, Wei; Li, Xu; Zhao, Le

    2018-01-01

    The Warburg effect is one of the main energy metabolism features supporting cancer cell growth. 20(S)-Rg3 exerts anti-tumor effect on ovarian cancer partly by inhibiting the Warburg effect. microRNAs are important regulators of the Warburg effect. However, the microRNA regulatory network mediating the anti-Warburg effect of 20(S)-Rg3 was largely unknown. microRNA deep sequencing was performed to identify the 20(S)-Rg3-influenced microRNAs in SKOV3 ovarian cancer cells. miR-532-3p was overexpressed by mimic532-3p transfection in SKOV3 and A2780 cells or inhibited by inhibitor532-3p transfection in 20(S)-Rg3-treated cells to examine the changes in HK2 and PKM2 expression, glucose consumption, lactate production and cell growth. Dual-luciferase reporter assay was conducted to verify the direct binding of miR-532-3p to HK2. The methylation status in the promoter region of pre-miR-532-3p gene was examined by methylation-specific PCR. Expression changes of key molecules controlling DNA methylation including DNMT1, DNMT3A, DNMT3B, and TET1-3 were examined in 20(S)-Rg3-treated cells. DNMT3A was overexpressed in 20(S)-Rg3-treated cells to examine its influence on miR-532-3p level, HK2 and PKM2 expression, glucose consumption and lactate production. Deep sequencing results showed that 11 microRNAs were increased and 9 microRNAs were decreased by 20(S)-Rg3 in SKOV3 cells, which were verified by qPCR. More than 2-fold increase of miR-532-3p was found in 20(S)-Rg3-treated SKOV3 cells. Forced expression of miR-532-3p reduced HK2 and PKM2 expression, glucose consumption and lactate production in SKOV3 and A2780 ovarian cancer cells. Inhibition of miR-532-3p antagonized the suppressive effect of 20(S)-Rg3 on HK2 and PKM2 expression, glucose consumption and lactate production in ovarian cancer cells. Dual-luciferase reporter assay showed that miR-532-3p directly suppressed HK2 rather than PKM2. miR-532-3p level was controlled by the methylation in the promoter region of its host

  14. Distribution of IGF receptors in the plasma membrane of proximal tubular cells

    International Nuclear Information System (INIS)

    Hammerman, M.R.; Rogers, S.

    1987-01-01

    To characterize the distribution of receptors for insulin-like growth factors I and II (IGF I and II) in the plasma membrane of the renal proximal tubular cell, the authors measured binding of 125 I-labeled IGF I and 125 I-labeled IGF II to proximal tubular basolateral and brush-border membranes and characterized IGF I-stimulated phosphorylation of detergent-solubilized membranes. 125 I-IGF bound primarily to a 135,000 relative molecular weight (M r ) protein and IGF II to a 260,000 M r protein in isolated membranes. Binding of 125 I-IGF I was severalfold greater in basolateral than in brush-border membranes. IGF I-stimulated phosphorylation of the 92,000 M r β-subunit of its receptors could be demonstrated only in basolateral membranes. These findings are consistent with an asymmetrical distribution of receptors for IGF I in the plasma membrane of the renal proximal tubular cell, localization being primary on the basolateral side. In contrast, binding of 125 I-IGF II to isolated basolateral and brush-border membranes was equivalent, suggesting that receptors for this peptide are distributed more symmetrically in the plasma membrane. The findings suggest that the action of IGF I in proximal tubule are mediated via interaction of circulating peptide with specific receptors in the basolateral membrane. However, the findings established the potential for actions of IGF II to be exerted in proximal tubule via interaction with both basolateral and/or brush-border membrane receptors

  15. Uptake of [3H]PAH and [14C]urate into isolated proximal tubular segments of the pig kidney

    International Nuclear Information System (INIS)

    Schali, C.; Roch-Ramel, F.

    1981-01-01

    Segments of proximal convoluted (PCT) and proximal straight (PST) tubules of minipigs and normal-sized pigs were microdissected (without collagenase treatment) and incubated (30 min, 37 0 C, pH 7.4) in Ringer solution (under O 2 ) containing [ 3 H]PAH (3.10 -5 M) or [ 14 C]urate (9.10 -5 M) and, in inhibitor studies, probenecid, pyrazinoic acid (PZA), urate, or PAH, all at 1 mM. In both strains the uptake of [ 3 H]PAH expressed as mean T/M ratio (cpm per ml tissue water/cpm per ml incubation medium) was significantly higher (P 14 C]urate. In eight minipigs the T/M was 4.9 +/- 0.5 in 24 PCT and 2 +/- 0.2 in 25 PST. In normal-sized pigs the T/M was 3.8 +/- 0.3 in 35 PCT (five pigs) and 1.9 +/- 0.4 in eight PST (two pigs). In inhibitor studies urate significantly depressed the uptake of [ 3 H]PAH, and unlabeled PAH depressed the uptake of [ 14 C]urate. PZA significantly inhibited the uptake of [ 14 C]urate but not that of [ 3 H]PAH, whereas probenecid had a strong inhibitory efect on the uptake of both compounds. These results suggest that [ 14 C]urate and [ 3 H]PAH are transported by a transport system located mainly in the proximal convoluted tubule. These findings are in contrast in the findings are in contrast to the findings obtained in rabbits in which the transport system of PAH and urate is mainly located in the proximal part of the pars recta

  16. Sorting Tubules Regulate Blood-Brain Barrier Transcytosis

    Directory of Open Access Journals (Sweden)

    Roberto Villaseñor

    2017-12-01

    Full Text Available Transcytosis across the blood-brain barrier (BBB regulates key processes of the brain, but the intracellular sorting mechanisms that determine successful receptor-mediated transcytosis in brain endothelial cells (BECs remain unidentified. Here, we used Transferrin receptor-based Brain Shuttle constructs to investigate intracellular transport in BECs, and we uncovered a pathway for the regulation of receptor-mediated transcytosis. By combining live-cell imaging and mathematical modeling in vitro with super-resolution microscopy of the BBB, we show that intracellular tubules promote transcytosis across the BBB. A monovalent construct (sFab sorted for transcytosis was localized to intracellular tubules, whereas a bivalent construct (dFab sorted for degradation formed clusters with impaired transport along tubules. Manipulating tubule biogenesis by overexpressing the small GTPase Rab17 increased dFab transport into tubules and induced its transcytosis in BECs. We propose that sorting tubules regulate transcytosis in BECs and may be a general mechanism for receptor-mediated transport across the BBB.

  17. Effects of vasopressin on the isolated perfused human collecting tubule.

    Science.gov (United States)

    Yanagawa, N; Trizna, W; Bar-Khayim, Y; Fine, L G

    1981-05-01

    Cortical collecting tubules (CCT) were dissected from the surviving normal tissue of human kidneys removed at operation for either carcinoma or calculus. These CCT's were perfused in vitro shortly after the nephrectomy was performed. Transtubular potential differences in different tubules varied from +3.2 to -2.0 mV and were reduced towards zero by lowering the temperature or by adding ouabain to the bath. In the absence of vasopressin, tubules were essentially impermeable to water with extremely low net water fluxes even in the presence of a transtubular osmotic gradient. Addition of vasopressin to the bath caused the transtubular osmotic water permeability coefficient to increase to values of 125, 175, and 155 X 10(-4) cm/sec in three tubules thus studied. These results demonstrate close similarities between the human CCT and the more extensively studied rabbit CCT.

  18. Magnetic properties of permalloy-coated organic tubules

    Science.gov (United States)

    Krebs, J. J.; Rubinstein, M.; Lubitz, P.; Harford, M. Z.; Baral, S.; Shashidar, R.; Ho, Y. S.; Chow, G. M.; Qadri, S.

    1991-11-01

    An initial investigation is presented of the ferromagnetic properties of a novel type of magnetic composite, viz., permalloy-coated submicron diameter hollow cylinders or tubules. The tubules form spontaneously from an organic material, a diacetylenic phosopholipid, and were used as templates on which the ferromagnetic material was deposited by electroless deposition. The permalloy-coated tubules were dispersed in an epoxy matrix to measure the magnetization and ferromagnetic resonance (FMR) properties of individual tubules. The nature of the magnetic anisotropy and the FMR spectra observed confirmed that the tubules are well aligned by a magnetic field during the epoxy curing. The FMR spectra are interpreted in terms of a powder pattern distribution of thin-film spectra consistent with the large diameter-to-thickness ratio.

  19. BAG3 regulates ECM accumulation in renal proximal tubular cells induced by TGF-β1.

    Science.gov (United States)

    Du, Feng; Li, Si; Wang, Tian; Zhang, Hai-Yan; Li, De-Tian; Du, Zhen-Xian; Wang, Hua-Qin; Wang, Yan-Qiu

    2015-01-01

    Previously we have demonstrated that Bcl-2-associated athanogene 3 (BAG3) is increased in renal fibrosis using a rat unilateral ureteral obstruction model. The current study investigated the role of BAG3 in renal fibrosis using transforming growth factor (TGF)-β1-treated human proximal tubular epithelial (HK-2) cells. An upregulation of BAG3 in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of BAG3 induction by shorting hairpin RNA suppressed the expression of ECM proteins but had no effect on PAI-1 expression induced by TGF-β1. Forced overexpression of BAG3 selectively increased collagens. TGF-β1-induced BAG3 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. In addition, forced BAG3 overexpression blocked attenuation of collagens expression by ERK1/2 and JNK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of BAG3, which would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.

  20. Effect of dental materials on gluconeogenesis in rat kidney tubules

    NARCIS (Netherlands)

    Reichl, F.X.; Durner, J.; Mückter, H.; Elsenhans, B.; Forth, W.; Kunzelmann, K.H.; Hickel, R.; Spahl, W.; Hume, W.R.; Moes, G.W.

    1999-01-01

    The effect of dental composite components triethyleneglycoldimethacrylate (TEGDMA) and hydroxyethylmethacrylate (HEMA) as well as mercuric chloride (HgCl2) and methylmercury chloride (MeHgCl) on gluconeogenesis was investigated in isolated rat kidney tubules. From starved rats kidney tubules were

  1. Puerarin Facilitates T-Tubule Development of Murine Embryonic Stem Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2014-07-01

    Full Text Available Aims: The embryonic stem cell-derived cardiomyocytes (ES-CM is one of the promising cell sources for repopulation of damaged myocardium. However, ES-CMs present immature structure, which impairs their integration with host tissue and functional regeneration. This study used murine ES-CMs as an in vitro model of cardiomyogenesis to elucidate the effect of puerarin, the main compound found in the traditional Chinese medicine the herb Radix puerariae, on t-tubule development of murine ES-CMs. Methods: Electron microscope was employed to examine the ultrastructure. The investigation of transverse-tubules (t-tubules was performed by Di-8-ANEPPS staining. Quantitative real-time PCR was utilized to study the transcript level of genes related to t-tubule development. Results: We found that long-term application of puerarin throughout cardiac differentiation improved myofibril array and sarcomeres formation, and significantly facilitated t-tubules development of ES-CMs. The transcript levels of caveolin-3, amphiphysin-2 and junctophinlin-2, which are crucial for the formation and development of t-tubules, were significantly upregulated by puerarin treatment. Furthermore, puerarin repressed the expression of miR-22, which targets to caveolin-3. Conclusion: Our data showed that puerarin facilitates t-tubule development of murine ES-CMs. This might be related to the repression of miR-22 by puerarin and upregulation of Cav3, Bin1 and JP2 transcripts.

  2. Dentinal tubules revealed with X-ray tensor tomography.

    Science.gov (United States)

    Jud, Christoph; Schaff, Florian; Zanette, Irene; Wolf, Johannes; Fehringer, Andreas; Pfeiffer, Franz

    2016-09-01

    Dentin is a mineralized material making up most of the tooth bulk. A system of microtubules, so called dentinal tubules, transverses it radially from the pulp chamber to the outside. This highly oriented structure leads to anisotropic mechanical properties directly connected to the tubules orientation and density: the ultimate tensile strength as well as the fracture toughness and the shear strength are largest perpendicular to dentinal tubules. Consequently, the fatigue strength depends on the direction of dentinal tubules, too. However, none of the existing techniques used to investigate teeth provide access to orientation and density of dentinal tubules for an entire specimen in a non-destructive way. In this paper, we measure a third molar human tooth both with conventional micro-CT and X-ray tensor tomography (XTT). While the achievable resolution in micro-CT is too low to directly resolve the dentinal tubules, we provide strong evidence that the direction and density of dentinal tubules can be indirectly measured by XTT, which exploits small-angle X-ray scattering to retrieve a 3D map of scattering tensors. We show that the mean directions of scattering structures correlate to the orientation of dentinal tubules and that the mean effective scattering strength provides an estimation of the relative density of dentinal tubules. Thus, this method could be applied to investigate the connection between tubule orientation and fatigue or tensile properties of teeth for a full sample without cutting one, non-representative peace of tooth out of the full sample. Copyright © 2016 The Academy of Dental Materials. All rights reserved.

  3. Effect of Content of Sulfate Groups in Seaweed Polysaccharides on Antioxidant Activity and Repair Effect of Subcellular Organelles in Injured HK-2 Cells

    Directory of Open Access Journals (Sweden)

    Xiao-Tao Ma

    2017-01-01

    Full Text Available This study aims to investigate the repair effect of subcellular structure injuries of the HK-2 cells of four degraded seaweed polysaccharides (DSPs, namely, the degraded Porphyra yezoensis, Gracilaria lemaneiformis, Sargassum fusiform, and Undaria pinnatifida polysaccharides. The four DSPs have similar molecular weight, but with different content of sulfate groups (i.e., 17.9%, 13.3%, 8.2%, and 5.5%, resp.. The damaged model was established using 2.8 mmol/L oxalate to injure HK-2 cells, and 60 μg/mL of various DSPs was used to repair the damaged cells. With the increase of sulfate group content in DSPs, the scavenging activity of radicals and their reducing power were all improved. Four kinds of DSPs have repair effect on the subcellular organelles of damaged HK-2 cells. After being repaired by DSPs, the release amount of lactate dehydrogenase was decreased, the integrity of cell membrane and lysosome increased, the Δψm increased, the cell of G1 phase arrest was inhibited, the proportion of S phase increased, and cell apoptotic and necrosis rates were significantly reduced. The greater the content of sulfate group is, the stronger is the repair ability of the polysaccharide. These DSPs, particularly the polysaccharide with higher sulfate group content, may be a potential drug for the prevention and cure of kidney stones.

  4. Palladium nanotubes formed by lipid tubule templating and their application in ethanol electrocatalysis.

    Science.gov (United States)

    Wang, Yinan; Ma, Shenghua; Su, Yingchun; Han, Xiaojun

    2015-04-13

    Palladium nanotubes were fabricated by using lipid tubules as templates for the first time in a controlled manner. The positively charged lipid 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) was doped into lipid tubules to adsorb PdCl4 (2-) on the tubule surfaces for further reduction. The lipid tubule formation was optimized by studying the growing dynamics and ethanol/water ratio. The DOTAP-doped tubules showed pH stability from 0 to 14, which makes them ideal templates for metal plating. The Pd nanotubes are open-ended with a tunable wall thickness. They exhibited good electrocatalytic performance in ethanol. Their electrochemically active surface areas were 6.5, 10.6, and 83.2 m(2)  g(-1) for Pd nanotubes with 77, 101, and 150 nm wall thickness, respectively. These Pd nanotubes have great potential in fuel cells. The method demonstrated also opens up a way to synthesize hollow metal nanotubes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Lithium-, r- and s-Enhanced Metal-Poor Giant HK-II 17435-00532

    International Nuclear Information System (INIS)

    Roederer, Ian U.; Prieto, Carlos Allende; Sneden, Christopher; Frebel, Anna; Shetrone, Matthew; Rhee, Jaehyon; Gallino, Roberto; Bisterzo, Sara; Beers, Timothy C.; Cowan, John J.

    2008-01-01

    We present the first detailed abundance analysis of the metal-poor giant HK-II 17435-00532. This star was observed as part of the University of Texas Long-Term Chemical Abundances of Stars in the Halo (CASH) Project. A spectrum was obtained with the High Resolution Spectrograph (HRS) on the Hobby-Eberly Telescope with a resolving power of R∼15000. Our analysis reveals that this star may be located on the red giant branch, red horizontal branch, or early asymptotic giant branch. We find that this metal-poor ([Fe/H] = -2.2) star has an unusually high lithium abundance (logε(Li) = +2.1), mild carbon ([C/Fe] = +0.7) and sodium ([Na/Fe] = +0.6) enhancement, as well as enhancement of both s-process ([Ba/Fe] = +0.8) and r-process ([Eu/Fe] = +0.5) material. The high Li abundance can be explained by self-enrichment through extra mixing mechanisms that connect the convective envelope with the outer regions of the H-burning shell. If so, HK-II 17435-00532 is the most metal-poor starin which this short-lived phase of Li enrichment has been observed. The r- and s-process material was not produced in this star but was either present in the gas from which HK-II 17435-00532 formed or was transferred to it from a more massive binary companion. Despite the current non-detection of radial velocity variations (over a time span of ∼180 days), it is possible that HK-II 17435-00532 is in a long-period binary system, similar to other stars with both r and s enrichment

  6. Solo and keratin filaments regulate epithelial tubule morphology.

    Science.gov (United States)

    Nishimura, Ryosuke; Kato, Kagayaki; Fujiwara, Sachiko; Ohashi, Kazumasa; Mizuno, Kensaku

    2018-04-28

    Epithelial tubules, consisting of the epithelial cell sheet with a central lumen, are the basic structure of many organs. Mechanical forces play an important role in epithelial tubulogenesis; however, little is known about the mechanisms controlling the mechanical forces during epithelial tubule morphogenesis. Solo (also known as ARHGEF40) is a RhoA-targeting guanine-nucleotide exchange factor that is involved in mechanical force-induced RhoA activation and stress fiber formation. Solo binds to keratin-8/keratin-18 (K8/K18) filaments, and this interaction plays a crucial role in mechanotransduction. In this study, we examined the roles of Solo and K8/K18 filaments in epithelial tubulogenesis using MDCK cells cultured in 3D collagen gels. Knockdown of either Solo or K18 resulted in rounder tubules with increased lumen size, indicating that Solo and K8/K18 filaments play critical roles in forming the elongated morphology of epithelial tubules. Moreover, knockdown of Solo or K18 decreased the level of diphosphorylated myosin light chain (a marker of contractile force) at the luminal and outer surfaces of tubules, suggesting that Solo and K8/K18 filaments are involved in the generation of the myosin II-mediated contractile force during epithelial tubule morphogenesis. In addition, K18 filaments were normally oriented along the long axis of the tubule, but knockdown of Solo perturbed their orientation. These results suggest that Solo plays crucial roles in forming the elongated morphology of epithelial tubules and in regulating myosin II activity and K18 filament organization during epithelial tubule formation.

  7. The Flavonoid Apigenin Ameliorates Cisplatin-Induced Nephrotoxicity through Reduction of p53 Activation and Promotion of PI3K/Akt Pathway in Human Renal Proximal Tubular Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Sung Min Ju

    2015-01-01

    Full Text Available Apigenin is a member of the flavone subclass of flavonoids present in fruits and vegetables. Apigenin has long been considered to have various biological activities, such as antioxidant, anti-inflammatory, and antitumorigenic properties, in various cell types. Cisplatin was known to exhibit cytotoxic effect to renal cells by inducing apoptosis through activation of p53. The present study investigated the antiapoptotic effects of apigenin on the cisplatin-treated human renal proximal tubular epithelial (HK-2 cells. HK-2 cells were pretreated with apigenin (5, 10, 20 μM for 1 h and then treated with 40 μM cisplatin for various times. Apigenin inhibited the cisplatin-induced apoptosis of HK-2 cells. Interestingly, apigenin itself exerted cytostatic activity because of its ability to induce cell cycle arrest. Apigenin inhibited caspase-3 activity and PARP cleavage in cisplatin-treated cells. Apigenin reduced cisplatin-induced phosphorylation and expression of p53, with no significant influence on production of ROS that is known to induce p53 activation. Furthermore, apigenin promoted cisplatin-induced Akt phosphorylation, suggesting that enhanced Akt activation may be involved in cytoprotection. Taken together, these results suggest that apigenin ameliorates cisplatin-induced apoptosis through reduction of p53 activation and promotion of PI3K/Akt pathway in HK-2 cells.

  8. RNA sequencing of kidney distal tubule cells reveals multiple mediators of chronic aldosterone action

    DEFF Research Database (Denmark)

    Poulsen, Søren Brandt; Limbutara, Kavee; Fenton, Robert Andrew

    2018-01-01

    The renal aldosterone-sensitive distal tubule (ASDT) is crucial for sodium reabsorption and blood pressure regulation. The ASDT consists of the late distal convoluted tubule (DCT2), connecting tubule (CNT) and collecting duct. Due to difficulties in isolating epithelial cells from the ASDT in lar...

  9. Direct Reprogramming of Human Bone Marrow Stromal Cells into Functional Renal Cells Using Cell-free Extracts

    Directory of Open Access Journals (Sweden)

    Evangelia Papadimou

    2015-04-01

    Full Text Available The application of cell-based therapies in regenerative medicine is gaining recognition. Here, we show that human bone marrow stromal cells (BMSCs, also known as bone-marrow-derived mesenchymal cells, can be reprogrammed into renal proximal tubular-like epithelial cells using cell-free extracts. Streptolysin-O-permeabilized BMSCs exposed to HK2-cell extracts underwent morphological changes—formation of “domes” and tubule-like structures—and acquired epithelial functional properties such as transepithelial-resistance, albumin-binding, and uptake and specific markers E-cadherin and aquaporin-1. Transmission electron microscopy revealed the presence of brush border microvilli and tight intercellular contacts. RNA sequencing showed tubular epithelial transcript abundance and revealed the upregulation of components of the EGFR pathway. Reprogrammed BMSCs integrated into self-forming kidney tissue and formed tubular structures. Reprogrammed BMSCs infused in immunodeficient mice with cisplatin-induced acute kidney injury engrafted into proximal tubuli, reduced renal injury and improved function. Thus, reprogrammed BMSCs are a promising cell resource for future cell therapy.

  10. Yrityksen sähköinen markkinointiviestintä : edullisesti lisäarvoa asiakkaalle

    OpenAIRE

    Lietzén, Laura

    2012-01-01

    Tämän opinnäytetyön tarkoituksena on pohtia miten paikallinen pieni autokorjaamo voi luoda asiakkaalle lisäarvoa sähköisen markkinointiviestinnän avulla. Työssä keskitytään sähköisen markkinointiviestinnän osalta sosiaalisen median valjastamiseen yrityskäyttöön sekä vuorovaikutuksen luomiseen yrityksen ja asiakkaiden välillä. Perinteinen markkinointiviestintä on ollut yrityksien yksinhuutelua asiakkaille, kun taas nykyisin erityisesti sähköisessä maailmassa vuoropuhelu on tärkeä osa toimintaa...

  11. NRC Information No. 89-86: Type HK circuit breakers missing close latch anti-shock springs

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1992-01-01

    During the recent refueling outage at Fermi Unit 2, the licensee inspected both safety-related and non-safety-related Type HK circuit breakers. The close latch anti-shock springs were observed to be missing in approximately 40 safety-related Type HK circuit breakers that had been manufactured outside of the previously identified timeframes. (The identified circuit breakers were manufactured in 1974.) Thus, the timeframes previously identified by the manufacturer (prior to 1973 and from June 1975 to June 1977) may not be totally inclusive. In addition, because of changes in corporate name, mergers, etc., Type HK circuit breakers may indicate manufacture by ITE, ITE Imperial, Gould, Brown Boveri, or a combination thereof. The current name of the manufacturer is ASEA Brown Boveri. Recipients may need to be cognizant of this when determining whether they utilize potentially affected equipment

  12. Malpighian Tubules as Novel Targets for Mosquito Control

    Directory of Open Access Journals (Sweden)

    Peter M. Piermarini

    2017-01-01

    Full Text Available The Malpighian tubules and hindgut are the renal excretory tissues of mosquitoes; they are essential to maintaining hemolymph water and solute homeostasis. Moreover, they make important contributions to detoxifying metabolic wastes and xenobiotics in the hemolymph. We have focused on elucidating the molecular mechanisms of Malpighian tubule function in adult female mosquitoes and developing chemical tools as prototypes for next-generation mosquitocides that would act via a novel mechanism of action (i.e., renal failure. To date, we have targeted inward rectifier potassium (Kir channels expressed in the Malpighian tubules of the yellow fever mosquito Aedes aegypti and malaria mosquito Anopheles gambiae. Inhibition of these channels with small molecules inhibits transepithelial K+ and fluid secretion in Malpighian tubules, leading to a disruption of hemolymph K+ and fluid homeostasis in adult female mosquitoes. In addition, we have used next-generation sequencing to characterize the transcriptome of Malpighian tubules in the Asian tiger mosquito Aedes albopictus, before and after blood meals, to reveal new molecular targets for potentially disrupting Malpighian tubule function. Within 24 h after a blood meal, the Malpighian tubules enhance the mRNA expression of genes encoding mechanisms involved with the detoxification of metabolic wastes produced during blood digestion (e.g., heme, NH3, reactive oxygen species. The development of chemical tools targeting these molecular mechanisms in Malpighian tubules may offer a promising avenue for the development of mosquitocides that are highly-selective against hematophagous females, which are the only life stage that transmits pathogens.

  13. Effect of theobromine-containing toothpaste on dentin tubule occlusion in situ.

    Science.gov (United States)

    Amaechi, Bennett T; Mathews, Sapna M; Mensinkai, Poornima K

    2015-01-01

    Dentin hypersensitivity (DH) is treated by either occlusion of dentin tubules or nerve desensitization. This in situ study compared dentin tubules occlusion by theobromine-containing dentifrices with (Theodent-classic-F®, TCF) and without (Theodent-classic®, TC) fluoride with 1,500 ppm fluoride toothpaste, Colgate®-Regular (Fluoride) and Novamin®-containing toothpaste, Sensodyne®-5000-Nupro (Novamin®). Each subject wore four intraoral appliances bearing dentin blocks while using one of four test dentifrices (n = 20/dentifrice) twice daily for 7 days. The four appliances were removed successively after 1, 2, 3, and 7 days. Treated blocks and their control (untreated) blocks were examined with scanning electron microscopy (SEM). Effects were compared statistically (ANOVA/Tukey's) based on percentage of surface area covered by deposited precipitate layer (%DPL) and percentage of fully open (%FOT), partially occluded (%POT), and completely occluded (%COT) tubules in each block calculated relative to the number of tubules in their control blocks. SEM observation indicated an increased %COT and %DPL over time. After 1 and 2 days, %COT was comparable with TC and TCF, and significantly (p Theobromine-containing toothpastes with and without fluoride have equal potential in occluding dentin tubules within a shorter time period than Novamin®-containing toothpaste; however, the three demonstrated equal potential after 1 week, but not the fluoride toothpaste. Theobromine-containing toothpaste promoted dentin tubule occlusion thus shows potential to relief DH.

  14. Locally formed dopamine inhibits Na sup + -K sup + -ATPase activity in rat renal cortical tubule cells

    Energy Technology Data Exchange (ETDEWEB)

    Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J. (Harvard Medical School, Boston, MA (USA) Karolinska Institute, Stockholm (Sweden))

    1988-10-01

    Dopamine, generated locally from L-dopa, inhibits Na{sup +}-K{sup +}-ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na{sup +}-K{sup +}-ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate ({dot Q}o{sub 2}) and {sup 86}Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive {dot Q}o{sub 2} or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive {dot Q}o{sub 2} in a concentration-dependent manner, with half-maximal inhibition (K{sub 0.5}) of 5 {times} 10{sup {minus}7} M and a maximal inhibition of 14.1 {plus minus} 1.5% at 10{sup {minus}4}M. L-Dopa also blunted the nystatin-stimulated {dot Q}o{sub 2} in a concentration-dependent manner, indicating the L-dopa directly inhibits Na{sup +}-K{sup +}-ATPase activity and not sodium entry. Ouabain-sensitive {sup 86}Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} and {sup 86}Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na{sup +}-K{sup +}-ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner.

  15. Self-(Un)rolling Biopolymer Microstructures: Rings, Tubules, and Helical Tubules from the Same Material.

    Science.gov (United States)

    Ye, Chunhong; Nikolov, Svetoslav V; Calabrese, Rossella; Dindar, Amir; Alexeev, Alexander; Kippelen, Bernard; Kaplan, David L; Tsukruk, Vladimir V

    2015-07-13

    We have demonstrated the facile formation of reversible and fast self-rolling biopolymer microstructures from sandwiched active-passive, silk-on-silk materials. Both experimental and modeling results confirmed that the shape of individual sheets effectively controls biaxial stresses within these sheets, which can self-roll into distinct 3D structures including microscopic rings, tubules, and helical tubules. This is a unique example of tailoring self-rolled 3D geometries through shape design without changing the inner morphology of active bimorph biomaterials. In contrast to traditional organic-soluble synthetic materials, we utilized a biocompatible and biodegradable biopolymer that underwent a facile aqueous layer-by-layer (LbL) assembly process for the fabrication of 2D films. The resulting films can undergo reversible pH-triggered rolling/unrolling, with a variety of 3D structures forming from biopolymer structures that have identical morphology and composition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Study of the permeability of the various parts of the tubules to sodium and potassium ions

    International Nuclear Information System (INIS)

    Morel, F.; Falbriard, A.

    1959-01-01

    The method of stop flow analysis has been used in rabbits together with radioactive sodium and potassium injected in the middle of a six minutes period of arrest of urine flow during an osmotic diuresis. Urine was subsequently collected in 60 ta 80 mg samples. The specific activities of sodium and potassium suggest that both ions pass directly from the renal interstitial tissue into the urine at different and distinct areas in the tubules. The whole distal segment, including the area of active reabsorption of this ion, is impermeable to sodium in the direction interstitial tissue to lumen. The adjacent, more proximal tubule is, however, extremely permeable. The distal tubular impermeability to potassium is more limited. The specific activity already having reached a maximum at the level of active sodium reabsorption. Reprint of a paper published in 'Revue Francaise d'Etudes Cliniques et Biologiques', n. 5, vol IV, p. 471-474 [fr

  17. Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

    Directory of Open Access Journals (Sweden)

    Ana Tobar

    Full Text Available BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03. Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001, a 94% higher Bowman's space volume (P=0.003, a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02 and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01. The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity

  18. Regulation of proximal tubular epithelial cell CD44-mediated binding and internalisation of hyaluronan.

    Science.gov (United States)

    Jones, Stuart George; Ito, Takafumi; Phillips, Aled Owain

    2003-09-01

    Increased expression of the connective tissue polysaccharide hyaluronan (HA) in the renal corticointerstitium is associated with progressive renal fibrosis. Numerous studies have demonstrated involvement proximal tubular epithelial cells in the fibrotic process and in the current study we have characterised their expression of the HA receptor, CD44, and examined changes in CD44 expression and function in response to either IL-1beta or glucose. Characterisation of CD44 splice variant expression was carried out in primary cultures of human proximal tubular cells (PTC) and HK2 cells. Binding and internalisation HA was examined by addition of exogenous of fluorescein-HA (fl-HA), and expression of CD44 examined by immunoblot analysis and flow cytometry. Alteration in "functional" CD44 was determined by immunoprecipitation of CD44 following stimulation in the presence of fl-HA. PTC, both primary culture and the PTC cell line, HK2, express at least 5 CD44 splice variants, the expression of which are not altered by addition of either IL-1beta or 25mM D-glucose. Addition of either stimulus increased cell surface binding and internalisation of fl-HA and increased expression of functionally active CD44. Increased binding and internalisation of fl-HA, was blocked by anti-CD44 antibody, and by the inhibition of O-glycosylation. The data demonstrate that stimuli inducing PTC HA synthesis also regulate PTC-HA interactions. Furthermore increased HA binding and internalisation is the result of post-translational modification of CD44 by O-glycosylation, rather than by alteration in expression of CD44 at the cell surface, or by alternate use of CD44 splice variants.

  19. Aurinkosähkön hyödyntäminen veneen pääasiallisena energialähteenä

    OpenAIRE

    Seppälä, Heikki

    2013-01-01

    Opinnäytetyö käsittelee aurinkosähkön hyödyntämistä sähköpropulsiolla varustetun veneen energialähteenä. Työssä tällaista venettä nimitetään aurinkosähköveneeksi. Aurinkosähköveneiden määrä on toistaiseksi pieni, mutta tilanne saattaa muuttua lähitulevaisuudessa. Tämän työn tarkoituksena on ollut selvittää aurinkosähköveneen kehittymismahdollisuudet yleiseksi venemalliksi ja aurinkosähköveneen suunnitteluprosessiin vaikuttavat tekijät. Näistä asioista kertovaa kirjallisuutta tai muita laajoja...

  20. The myopathy-causing mutation DNM2-S619L leads to defective tubulation in vitro and in developing zebrafish

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Gibbs

    2014-01-01

    Full Text Available DNM2 is a ubiquitously expressed GTPase that regulates multiple subcellular processes. Mutations in DNM2 are a common cause of centronuclear myopathy, a severe disorder characterized by altered skeletal muscle structure and function. The precise mechanisms underlying disease-associated DNM2 mutations are unresolved. We examined the common DNM2-S619L mutation using both in vitro and in vivo approaches. Expression of DNM2-S619L in zebrafish led to the accumulation of aberrant vesicular structures and to defective excitation-contraction coupling. Expression of DNM2-S619L in COS7 cells resulted in defective BIN1-dependent tubule formation. These data suggest that DNM2-S619L causes disease, in part, by interfering with membrane tubulation.

  1. Melatonin protects cardiac microvasculature against ischemia/reperfusion injury via suppression of mitochondrial fission-VDAC1-HK2-mPTP-mitophagy axis.

    Science.gov (United States)

    Zhou, Hao; Zhang, Ying; Hu, Shunying; Shi, Chen; Zhu, Pingjun; Ma, Qiang; Jin, Qinhua; Cao, Feng; Tian, Feng; Chen, Yundai

    2017-08-01

    The cardiac microvascular system, which is primarily composed of monolayer endothelial cells, is the site of blood supply and nutrient exchange to cardiomyocytes. However, microvascular ischemia/reperfusion injury (IRI) following percutaneous coronary intervention is a woefully neglected topic, and few strategies are available to reverse such pathologies. Here, we studied the effects of melatonin on microcirculation IRI and elucidated the underlying mechanism. Melatonin markedly reduced infarcted area, improved cardiac function, restored blood flow, and lower microcirculation perfusion defects. Histological analysis showed that cardiac microcirculation endothelial cells (CMEC) in melatonin-treated mice had an unbroken endothelial barrier, increased endothelial nitric oxide synthase expression, unobstructed lumen, reduced inflammatory cell infiltration, and less endothelial damage. In contrast, AMP-activated protein kinase α (AMPKα) deficiency abolished the beneficial effects of melatonin on microvasculature. In vitro, IRI activated dynamin-related protein 1 (Drp1)-dependent mitochondrial fission, which subsequently induced voltage-dependent anion channel 1 (VDAC1) oligomerization, hexokinase 2 (HK2) liberation, mitochondrial permeability transition pore (mPTP) opening, PINK1/Parkin upregulation, and ultimately mitophagy-mediated CMEC death. However, melatonin strengthened CMEC survival via activation of AMPKα, followed by p-Drp1 S616 downregulation and p-Drp1 S37 upregulation, which blunted Drp1-dependent mitochondrial fission. Suppression of mitochondrial fission by melatonin recovered VDAC1-HK2 interaction that prevented mPTP opening and PINK1/Parkin activation, eventually blocking mitophagy-mediated cellular death. In summary, this study confirmed that melatonin protects cardiac microvasculature against IRI. The underlying mechanism may be attributed to the inhibitory effects of melatonin on mitochondrial fission-VDAC1-HK2-mPTP-mitophagy axis via activation

  2. Parima ulmeteose kirjutas Kivirähk

    Index Scriptorium Estoniae

    2008-01-01

    Ulmeauhind Stalker 2008 - tõlkeromaan: Martin, George R. R. Troonide mäng / tlk. Mario Kivistik; tõlkejutt: Card, Orson Scott. Kuninglik liha; algupärane raamat: Kivirähk, Andrus. Mees, kes teadis ussisõnu; algupärane jutt: Veskimees, Siim. Keskpäevapimedus; parim eesti autori jutt: Risto, Taivo. Laatsaruse rahamasin. Vt. ka Looming, 2008, nr. 8, lk. 1271

  3. Approaching to DM2 through sodium-glucose cotransporter-2: does it make sense?

    Science.gov (United States)

    Segura, Julián

    2016-11-01

    The kidney is involved in glucose homeostasis through three main mechanisms: renal gluconeogenesis, renal glucose consumption and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most relevant physiological functions of the kidney, through which filtered glucose is fully recovered, urine is free of glucose, and calorie loss is prevented. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where GLUT2 and SGLT2 transporters are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycaemia, the kidney continues reabsorbing glucose, and hyperglycaemia is maintained. Most renal glucose reabsorption is mediated by the SGLT2 transporter. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  4. Numerical Analysis of the Effect of T-tubule Location on Calcium Transient in Ventricular Myocytes

    Science.gov (United States)

    George, Uduak Z.; Wang, Jun; Yu, Zeyun

    2013-01-01

    Intracellular calcium (Ca2+) signaling in cardiac myocytes is vital for proper functioning of the heart. Understanding the intracellular Ca2+ dynamics would give an insight into the functions of normal and diseased hearts. In the current study, spatiotemporal Ca2+ dynamics is investigated in ventricular myocytes by considering Ca2+ release and re-uptake via sarcolemma and transverse tubules (T-tubules), Ca2+ diffusion and buffering in the cytosol, and the blockade of Ca2+ activities associated with the sarcoplasmic reticulum. This study is carried out using a three dimensional (3D) geometric model of a branch of T-tubule extracted from the electron microscopy (EM) images of a partial ventricular myocyte. Mathematical modeling is done by using a system of partial differential equations involving Ca2+ , buffers, and membrane channels. Numerical simulation results suggest that a lack of T-tubule structure at the vicinity of the cell surface could increase the peak time of Ca2+ concentration in myocytes. The results also show that T-tubules and mobile buffers play an important role in the regulation of Ca2+ transient in ventricular myocytes. PMID:24212025

  5. The synthesis, structure-toxicity relationship of cisplatin derivatives for the mechanism research of cisplatin-induced nephrotoxicity.

    Science.gov (United States)

    Hu, Jing; Wu, Tian-Ming; Li, Hong-Ze; Zuo, Ze-Ping; Zhao, Ying-Lan; Yang, Li

    2017-08-01

    Cisplatin is a widely used antineoplastic drug, while its nephrotoxicity limits the clinical application. Although several mechanisms contributing to nephrotoxicity have been reported, the direct protein targets are unclear. Herein we reported the synthesis of 29 cisplatin derivatives and the structure-toxicity relationship (STR) of these compounds with MTT assay in human renal proximal tubule cells (HK-2) and pig kidney epithelial cells (LLC-PK1). To the best of our knowledge, this study represented the first report regarding the structure-toxicity relationship (STR) of cisplatin derivatives. The potency of biotin-pyridine conjugated derivative 3 met the requirement for target identification, and the preliminary chemical proteomics results suggested that it is a promising tool for further target identification of cisplatin-induced nephrotoxicity. Copyright © 2017. Published by Elsevier Ltd.

  6. Paperisen ja sähköisen taloushallinnon prosessien vertailua

    OpenAIRE

    Aakula, Kreetta

    2015-01-01

    Yrityksen taloushallintoon kuuluu monia tärkeitä tehtäviä: laskutus, laskujen maksu, tilausten lähetys, palkanlaskenta, kirjanpito ja työnantaja- ja veroilmoitusten laadinta. Nämä asiat voidaan tänä päivänä hoitaa vähemmällä työllä siirtymällä sähköiseen taloushallintoon. Sähköinen automatisoitu taloushallinto mahdollistaa töiden uudelleen järjestämisen ajasta ja paikasta riippumatta, tehostaa yrityksen taloushallintoa ja alentaa kustannuksia. Opinnäytetyöni tutkimusongelma oli se, miten t...

  7. The Hong Kong version of the Oxford Cognitive Screen (HK-OCS): validation study for Cantonese-speaking chronic stroke survivors.

    Science.gov (United States)

    Kong, Anthony Pak-Hin; Lam, Pinky Hiu-Ping; Ho, Diana Wai-Lam; Lau, Johnny King; Humphreys, Glyn W; Riddoch, Jane; Weekes, Brendan

    2016-09-01

    This study reports the validation of the Hong Kong version of Oxford Cognitive Screen (HK-OCS). Seventy Cantonese-speaking healthy individuals participated to establish normative data and 46 chronic stroke survivors were assessed using the HK-OCS, Albert's Test of Visual Neglect, short test of gestural production, and Hong Kong version of the following assessments: Western Aphasia Battery, MMSE, MoCA, Modified Barthel Index, and Lawton Instrumental Activities of Daily Living scale. The validity of the HK-OCS was appraised by the difference between the two participant groups. Neurologically unimpaired individuals performed significantly better than stroke survivors on the HK-OCS. Positive and significant correlations found between cognitive subtests in the HK-OCS and related assessments indicated good concurrent validity. Excellent intra-rater and inter-rater reliabilities, fair test-retest reliability, and acceptable internal consistency suggested that the HK-OCS had good reliability. Specific HK-OCS subtests including semantics, episodic memory, number writing, and orientation were the best predictors of functional outcomes.

  8. Role of ARF6 in internalization of metal-binding proteins, metallothionein and transferrin, and cadmium-metallothionein toxicity in kidney proximal tubule cells

    International Nuclear Information System (INIS)

    Wolff, Natascha A.; Lee, Wing-Kee; Abouhamed, Marouan; Thevenod, Frank

    2008-01-01

    Filtered metal-protein complexes, such as cadmium-metallothionein-1 (CdMT-1) or transferrin (Tf) are apically endocytosed partly via megalin/cubilin by kidney proximal tubule (PT) cells where CdMT-1 internalization causes apoptosis. Small GTPase ARF (ADP-ribosylation factor) proteins regulate endocytosis and vesicular trafficking. We investigated roles of ARF6, which has been shown to be involved in internalization of ligands and endocytic trafficking in PT cells, following MT-1/CdMT-1 and Tf uptake by PT cells. WKPT-0293 Cl.2 cells derived from rat PT S1 segment were transfected with hemagglutinin-tagged wild-type (ARF6-WT) or dominant negative (ARF6-T27N) forms of ARF6. Using immunofluorescence, endogenous ARF6 was associated with the plasma membrane (PM) as well as juxtanuclear and co-localized with Rab5a and Rab11 involved in early and recycling endosomal trafficking. Immunofluorescence staining of megalin showed reduced surface labelling in ARF6 dominant negative (ARF6-DN) cells. Intracellular Alexa Fluor 546-conjugated MT-1 uptake was reduced in ARF6-DN cells and CdMT-1 (14.8 μM for 24 h) toxicity was significantly attenuated from 27.3 ± 3.9% in ARF6-WT to 11.1 ± 4.0% in ARF6-DN cells (n = 6, P < 0.02). Moreover, reduced Alexa Fluor 546-conjugated Tf uptake was observed in ARF-DN cells (75.0 ± 4.6% versus 3.9 ± 3.9% of ARF6-WT cells, n = 3, P < 0.01) and/or remained near the PM (89.3 ± 5. 6% versus 45.2 ± 14.3% of ARF6-WT cells, n = 3, P < 0.05). In conclusion, the data support roles for ARF6 in receptor-mediated endocytosis and trafficking of MT-1/Tf to endosomes/lysosomes and CdMT-1 toxicity of PT cells

  9. Genetic ablation of AQP2 in the mouse connecting tubules results in a mild urinary concentrating defect

    DEFF Research Database (Denmark)

    Kortenoeven, Marleen; Pedersen, Nis Borbye; Miller, Lance

    Body water balance is regulated in the kidney via the vasopressin (AVP) regulated water channel aquaporin-2 (AQP2) expressed in the connecting tubule (CNT) and the collecting duct (CD). Although crucial for the urinary concentrating mechanism, the relative role of AQP2 in the CNT and CD are not f...

  10. Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

    Science.gov (United States)

    Sabin, Charles; Corti, Davide; Buzon, Victor; Seaman, Mike S; Lutje Hulsik, David; Hinz, Andreas; Vanzetta, Fabrizia; Agatic, Gloria; Silacci, Chiara; Mainetti, Lara; Scarlatti, Gabriella; Sallusto, Federica; Weiss, Robin; Lanzavecchia, Antonio; Weissenhorn, Winfried

    2010-11-18

    The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

  11. The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode As Deflagrations?

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.M.; Li, W.; Frieman, J.A.; Blinnikov, S.I.; DePoy, D.; Prieto, J.L.; Milne, P.; Contreras, C.; Folatelli, Gaston; Morrell, N.; Hamuy, M.; Suntzeff, N.B.; Roth, M.; Gonzalez, S.; Krzeminski, W.; Filippenko, A.V.; Freedman, W.L.; Chornock, R.; Jha, S.; Madore, B.F.; Persson, S.E.; /Las Campanas Observ. /UC, Berkeley, Astron. Dept.

    2006-11-14

    We present extensive u{prime}g{prime}r{prime}i{prime} BV RIY JHK{sub s} photometry and optical spectroscopy of SN 2005hk. These data reveal that SN 2005hk was nearly identical in its observed properties to SN 2002cx, which has been called 'the most peculiar known type Ia supernova'. Both supernovae exhibited high ionization SN 1991T-like pre-maximum spectra, yet low peak luminosities like SN 1991bg. The spectra reveal that SN 2005hk, like SN 2002cx, exhibited expansion velocities that were roughly half those of typical type Ia supernovae. The R and I light curves of both supernovae were also peculiar in not displaying the secondary maximum observed for normal type Ia supernovae. Our Y JH photometry of SN 2005hk reveals the same peculiarity in the near-infrared. By combining our optical and near-infrared photometry of SN 2005hk with published ultraviolet light curves obtained with the Swift satellite, we are able to construct a bolometric light curve from {approx} 10 days before to {approx}60 days after B maximum. The shape and unusually low peak luminosity of this light curve, plus the low expansion velocities and absence of a secondary maximum at red and near-infrared wavelengths, are all in reasonable agreement with model calculations of a 3D deflagration which produces {approx} 0.25 M{sub {circle_dot}} of {sup 56}Ni.

  12. Accelerated recovery of renal mitochondrial and tubule homeostasis with SIRT1/PGC-1α activation following ischemia–reperfusion injury

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Jason A., E-mail: funkj@musc.edu [Center for Cell Death, Injury, and Regeneration, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Schnellmann, Rick G., E-mail: schnell@musc.edu [Center for Cell Death, Injury, and Regeneration, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Ralph H. Johnson VA Medical Center, Charleston, SC 29401 (United States)

    2013-12-01

    Kidney ischemia–reperfusion (I/R) injury elicits cellular injury in the proximal tubule, and mitochondrial dysfunction is a pathological consequence of I/R. Promoting mitochondrial biogenesis (MB) as a repair mechanism after injury may offer a unique strategy to restore both mitochondrial and organ function. Rats subjected to bilateral renal pedicle ligation for 22 min were treated once daily with the SIRT1 activator SRT1720 (5 mg/kg) starting 24 h after reperfusion until 72 h–144 h. SIRT1 expression was elevated in the renal cortex of rats after I/R + vehicle treatment (IRV), but was associated with less nuclear localization. SIRT1 expression was even further augmented and nuclear localization was restored in the kidneys of rats after I/R + SRT1720 treatment (IRS). PGC-1α was elevated at 72 h–144 h in IRV and IRS kidneys; however, SRT1720 treatment induced deacetylation of PGC-1α, a marker of activation. Mitochondrial proteins ATP synthase β, COX I, and NDUFB8, as well as mitochondrial respiration, were diminished 24 h–144 h in IRV rats, but were partially or fully restored in IRS rats. Urinary kidney injury molecule-1 (KIM-1) was persistently elevated in both IRV and IRS rats; however, KIM-1 tissue expression was attenuated in IRS rats. Additionally, sustained loss of Na{sup +},K{sup +}–ATPase expression and basolateral localization and elevated vimentin in IRV rats was normalized in IRS rats, suggesting restoration of a differentiated, polarized tubule epithelium. The results suggest that SRT1720 treatment expedited recovery of mitochondrial protein expression and function by enhancing MB, which was associated with faster proximal tubule repair. Targeting MB may offer unique therapeutic strategy following ischemic injury. - Highlights: • We examined recovery of mitochondrial and renal function after ischemia–reperfusion. • SRT1720 treatment after I/R induced mitochondrial biogenesis via SIRT1/PGC-1α. • Recovery of mitochondrial function was

  13. 3D variations in human crown dentin tubule orientation: a phase-contrast microtomography study.

    Science.gov (United States)

    Zaslansky, Paul; Zabler, Simon; Fratzl, Peter

    2010-01-01

    Tubules dominate the microstructure of dentin, and in crowns of human teeth they are surrounded by thick mineralized peritubular cuffs of high stiffness. Here we examine the three-dimensional (3D) arrangement of tubules in relation to enamel on the buccal and lingual aspects of intact premolars and molars. Specifically we investigate the angular orientation of tubules relative to the plane of the junction of dentin with enamel (DEJ) by means of wet, non-destructive and high-resolution phase-contrast (coherent) tomography. Enamel capped dentin samples (n=16), cut from the buccal and lingual surfaces of upper and lower premolar and molar teeth, were imaged in water by high-resolution synchrotron-based phase-contrast X-ray radiography. Reconstructed 3D virtual images were co-aligned with respect to the DEJ plane. The average tubule orientation was determined at increasing distances from the DEJ, based on integrated projections onto orthogonal virtual planes. The angle and curl of the tubules were determined every 100 microm to a depth of 1.4mm beneath the DEJ. Most tubules do not extend at right angles from the DEJ. Even when they do, tubules always change their orientations substantially within the first half-millimeter zone beneath the DEJ, both on the buccal and lingual aspects of premolar and molar teeth. Tubules also tend to curl and twist within this zone. Student t-tests indicate that lower teeth seem to have greater tilts in the tubule orientations relative to the DEJ normal with an average angle of 42 degrees (+/-2.0 degrees), whereas upper teeth exhibit a smaller change of orientation, with an average of 32 degrees (+/-2.1 degrees). Tubules are a central characteristic of dentin, with important implications on how it is arranged and what the properties are. Knowing about the path that tubules follow is important for various reasons, ranging form improving control over restorative procedures to understanding or simulating the mechanical properties of teeth

  14. Proteomic changes in response to crystal formation in Drosophila Malpighian tubules.

    Science.gov (United States)

    Chung, Vera Y; Konietzny, Rebecca; Charles, Philip; Kessler, Benedikt; Fischer, Roman; Turney, Benjamin W

    2016-04-02

    Kidney stone disease is a major health burden with a complex and poorly understood pathophysiology. Drosophila Malpighian tubules have been shown to resemble human renal tubules in their physiological function. Herein, we have used Drosophila as a model to study the proteomic response to crystal formation induced by dietary manipulation in Malpighian tubules. Wild-type male flies were reared in parallel groups on standard medium supplemented with lithogenic agents: control, Sodium Oxalate (NaOx) and Ethylene Glycol (EG). Malpighian tubules were dissected after 2 weeks to visualize crystals with polarized light microscopy. The parallel group was dissected for protein extraction. A new method of Gel Assisted Sample Preparation (GASP) was used for protein extraction. Differentially abundant proteins (p<0.05) were identified by label-free quantitative proteomic analysis in flies fed with NaOx and EG diet compared with control. Their molecular functions were further screened for transmembrane ion transporter, calcium or zinc ion binder. Among these, 11 candidate proteins were shortlisted in NaOx diet and 16 proteins in EG diet. We concluded that GASP is a proteomic sample preparation method that can be applied to individual Drosophila Malpighian tubules. Our results may further increase the understanding of the pathophysiology of human kidney stone disease.

  15. Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

    Directory of Open Access Journals (Sweden)

    Charles Sabin

    Full Text Available The human monoclonal antibody (mAb HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1 of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

  16. Family values in the age of genomics: comparative analyses of temperate bacteriophage HK022.

    Science.gov (United States)

    Weisberg, R A; Gottesmann, M E; Hendrix, R W; Little, J W

    1999-01-01

    HK022 is a temperate coliphage related to phage lambda. Its chromosome has been completely sequenced, and several aspects of its life cycle have been intensively studied. In the overall arrangement, expression, and function of most of its genes, HK022 broadly resembles lambda and other members of the lambda family. Upon closer view, significant differences emerge. The differences reveal alternative strategies used by related phages to cope with similar problems and illuminate previously unknown regulatory and structural motifs. HK022 prophages protect lysogens from superinfection by producing a sequence-specific RNA binding protein that prematurely terminates nascent transcripts of infecting phage. It uses a novel RNA-based mechanism to antiterminate its own early transcription. The HK022 protein shell is strengthened by a complex pattern of covalent subunit interlinking to form a unitary structure that resembles chain-mail armour. Its integrase and repressor proteins are similar to those of lambda, but the differences provide insights into the evolution of biological specificity and the elements needed for construction of a stable genetic switch.

  17. The Two- and Three-Dimensional Models of the HK-WISC: A Confirmatory Factor Analysis.

    Science.gov (United States)

    Chan, David W.; Lin, Wen-Ying

    1996-01-01

    Confirmatory analyses on the Hong Kong Wechsler Intelligence Scale for Children (HK-WISC) provided support for composite score interpretation based on the two- and three-dimensional models across age levels. Test sample was comprised of 1,100 children, ranging in age from 5 to 15 years at all 11 age levels specified by the HK-WISC. (KW)

  18. Proximal Tubular Secretion of Creatinine by Organic Cation Transporter OCT2 in Cancer Patients

    Science.gov (United States)

    Ciarimboli, Giuliano; Lancaster, Cynthia S.; Schlatter, Eberhard; Franke, Ryan M.; Sprowl, Jason A.; Pavenstädt, Hermann; Massmann, Vivian; Guckel, Denise; Mathijssen, Ron H. J.; Yang, Wenjian; Pui, Ching-Hon; Relling, Mary V.; Herrmann, Edwin; Sparreboom, Alex

    2012-01-01

    Purpose Knowledge of transporters responsible for the renal secretion of creatinine is key to a proper interpretation of serum creatinine and/or creatinine clearance as markers of renal function in cancer patients receiving chemotherapeutic agents. Experimental Design Creatinine transport was studied in transfected HEK293 cells in vitro and in wildtype mice and age-matched organic cation transporter 1 and 2-deficient [Oct1/2(−/−)] mice ex vivo and in vivo. Clinical pharmacogenetic and transport inhibition studies were done in two separate cohorts of cancer patients. Results Compared to wildtype mice, creatinine clearance was significantly impaired in Oct1/2(−/−) mice. Furthermore, creatinine inhibited organic cation transport in freshly-isolated proximal tubules from wild-type mice and humans, but not in those from Oct1/2(−/−) mice. In a genetic-association analysis (n=590), several polymorphisms around the OCT2/SLC22A2 gene locus, including rs2504954 (P=0.000873), were significantly associated with age-adjusted creatinine levels. Furthermore, in cancer patients (n=68), the OCT2 substrate cisplatin caused an acute elevation of serum creatinine (P=0.0083), consistent with inhibition of an elimination pathway. Conclusions Collectively, this study shows that OCT2 plays a decisive role in the renal secretion of creatinine. This process can be inhibited by OCT2 substrates, which impair the usefulness of creatinine as a marker of renal function. PMID:22223530

  19. Exposure to nerve growth factor worsens nephrotoxic effect induced by Cyclosporine A in HK-2 cells.

    Directory of Open Access Journals (Sweden)

    Donatella Vizza

    Full Text Available Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkA(NTR and p75(NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 (NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75(NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A.

  20. Human Papillomavirus 16 Infection Induces VAP-Dependent Endosomal Tubulation.

    Science.gov (United States)

    Siddiqa, Abida; Massimi, Paola; Pim, David; Broniarczyk, Justyna; Banks, Lawrence

    2018-03-15

    Human papillomavirus (HPV) infection involves complex interactions with the endocytic transport machinery, which ultimately facilitates the entry of the incoming viral genomes into the trans -Golgi network (TGN) and their subsequent nuclear entry during mitosis. The endosomal pathway is a highly dynamic intracellular transport system, which consists of vesicular compartments and tubular extensions, although it is currently unclear whether incoming viruses specifically alter the endocytic machinery. In this study, using MICAL-L1 as a marker for tubulating endosomes, we show that incoming HPV-16 virions induce a profound alteration in global levels of endocytic tubulation. In addition, we also show a critical requirement for the endoplasmic reticulum (ER)-anchored protein VAP in this process. VAP plays an essential role in actin nucleation and endosome-to-Golgi transport. Indeed, the loss of VAP results in a dramatic decrease in the level of endosomal tubulation induced by incoming HPV-16 virions. This is also accompanied by a marked reduction in virus infectivity. In VAP knockdown cells, we see that the defect in virus trafficking occurs after capsid disassembly but prior to localization at the trans -Golgi network, with the incoming virion-transduced DNA accumulating in Vps29/TGN46-positive hybrid vesicles. Taken together, these studies demonstrate that infection with HPV-16 virions induces marked alterations of endocytic transport pathways, some of which are VAP dependent and required for the endosome-to-Golgi transport of the incoming viral L2/DNA complex. IMPORTANCE Human papillomavirus infectious entry involves multiple interactions with the endocytic transport machinery. In this study, we show that incoming HPV-16 virions induce a dramatic increase in endocytic tubulation. This tubulation requires ER-associated VAP, which plays a critical role in ensuring the delivery of cargoes from the endocytic compartments to the trans -Golgi network. Indeed, the loss of

  1. Use of poly (amidoamine dendrimer for dentinal tubule occlusion: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Tianda Wang

    Full Text Available The occlusion of dentinal tubules is an effective method to alleviate the symptoms caused by dentin hypersensitivity, a significant health problem in dentistry and daily life. The in situ mineralization within dentinal tubules is a promising treatment for dentin hypersensitivity as it induces the formation of mineral on the sensitive regions and occludes the dentinal tubules. This study was carried out to evaluate the in vitro effect of a whole generation poly(amidoamine (PAMAM dendrimer (G3.0 on dentinal tubule occlusion by inducing mineralization within dentinal tubules. Dentin discs were treated with PAMAM dendrimers using two methods, followed by the in vitro characterization using Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR, X-ray diffraction (XRD, Field emission scanning electron microscopy (FE-SEM and Energy-Dispersive X-ray Spectroscopy (EDS. These results showed that G3.0 PAMAM dendrimers coated on dentin surface and infiltrated in dentinal tubules could induce hydroxyapatite formation and resulted in effective dentinal tubule occlusion. Moreover, crosslinked PAMAM dendrimers could induce the remineralization of demineralized dentin and thus had the potential in dentinal tubule occlusion. In this in vitro study, dentinal tubules occlusion could be achieved by using PAMAM dendrimers. This could lead to the development of a new therapeutic technique for the treatment of dentin hypersensitivity.

  2. Dried Colony in Cyanobacterium, Nostoc sp. HK-01 — Several high Space Environment Tolerances for ``Tanpopo'' Mission

    Science.gov (United States)

    Tomita-Yokotani, K.; Kimura, S.; Kimura, Y.; Igarashi, Y.; Ajioka, R.; Sato, S.; Katoh, H.; Baba, K.

    2013-11-01

    A cyanobacterium, Nostoc sp. HK-01, has high several space environmental tolerance. Nostoc sp HK-01 would have high contribution for the “Tanpopo” mission in Japan Experimental Module of the International Space Station.

  3. Species diversity regarding the presence of proximal tubular progenitor cells of the kidney

    Directory of Open Access Journals (Sweden)

    J. Hansson

    2016-02-01

    Full Text Available The cellular source for tubular regeneration following kidney injury is a matter of dispute, with reports suggesting a stem or progenitor cells as the regeneration source while linage tracing studies in mice seemingly favor the classical theory, where regeneration is performed by randomly surviving cells. We, and others have previously described a scattered cell population localized to the tubules of human kidney, which increases in number following injury. Here we have characterized the species distribution of these proximal tubular progenitor cells (PTPCs in kidney tissue from chimpanzee, pig, rat and mouse using a set of human PTPC markers. We detected PTPCs in chimpanzee and pig kidneys, but not in mouse tissue. Also, subjecting mice to the unilateral urethral obstruction model, caused clear signs of tubular injury, but failed to induce the PTPC phenotype in renal tubules.

  4. Genetic variant in HK1 is associated with a proanemic state and A1C but not other glycemic control-related traits

    DEFF Research Database (Denmark)

    Bonnefond, Amélie; Vaxillaire, Martine; Labrune, Yann

    2009-01-01

    OBJECTIVE: A1C is widely considered the gold standard for monitoring effective blood glucose levels. Recently, a genome-wide association study reported an association between A1C and rs7072268 within HK1 (encoding hexokinase 1), which catalyzes the first step of glycolysis. HK1 deficiency in eryt....... These findings may have implications for type 2 diabetes diagnosis and clinical management because anemia is a frequent complication of the diabetes state.......,694). In contrast, rs7072268-T allele decreases hemoglobin levels (n = 13,416; beta = -0.054 g/dl; P = 3.74 x 10(-6)) and hematocrit (n = 11,492; beta = -0.13%; P = 2.26 x 10(-4)), suggesting a proanemic effect. The T allele also increases risk for anemia (836 cases; odds ratio 1.13; P = 0.018). CONCLUSIONS: HK1...

  5. Strontium effects on root dentin tubule occlusion and nanomechanical properties.

    Science.gov (United States)

    Saeki, Kuniko; Marshall, Grayson W; Gansky, Stuart A; Parkinson, Charles R; Marshall, Sally J

    2016-02-01

    Dentin hypersensitivity often is treated by promotion of dentin tubule occlusion. In this in vitro study we evaluated nanomechanical properties and degree of tubule occlusion conferred to sound and demineralized human root dentin following treatment with a 10% (w/w) strontium acetate solution and its relation to the treatment duration and delivery method. 24 human cervical root dentin disks (8 groups of 3) were polished through 0.25 μm. 12 disks were subjected to an acid challenge (1% citric acid, pH 3.8) for 2 min. The specimens were incubated in artificial saliva, treated by soaking or brushing with deionized (DI) water or a solution of 10% strontium acetate for 2 min twice a day for 28 days. The occlusion percent and nanomechanical properties were determined at the baseline, 5, 14 and 28 days. Cross-sectioned specimens were prepared to evaluate the depth affected by strontium acetate / dentin interaction by SEM. Statistical analysis was performed using linear mixed effects models. A 10% strontium acetate treatment over 5-28 days significantly increased tubule occlusion for normal root dentin and to a lesser extent for demineralized dentin and increased the AFM based nanomechanical properties of demineralized dentin. Brushing was more effective than soaking in recovery of properties of demineralized dentin when treated with strontium. No difference in tubuleocclusion was found between the two delivery methods. Strontium acetate itself proved to have the ability to occlude dentin tubules and result in small changes in the mechanical properties of dentin. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Pseudomonas fluorescens HK44: Lessons Learned from a Model Whole-Cell Bioreporter with a Broad Application History

    Directory of Open Access Journals (Sweden)

    Gary S. Sayler

    2012-02-01

    Full Text Available Initially described in 1990, Pseudomonas fluorescens HK44 served as the first whole-cell bioreporter genetically endowed with a bioluminescent (luxCDABE phenotype directly linked to a catabolic (naphthalene degradative pathway. HK44 was the first genetically engineered microorganism to be released in the field to monitor bioremediation potential. Subsequent to that release, strain HK44 had been introduced into other solids (soils, sands, liquid (water, wastewater, and volatile environments. In these matrices, it has functioned as one of the best characterized chemically-responsive environmental bioreporters and as a model organism for understanding bacterial colonization and transport, cell immobilization strategies, and the kinetics of cellular bioluminescent emission. This review summarizes the characteristics of P. fluorescens HK44 and the extensive range of its applications with special focus on the monitoring of bioremediation processes and biosensing of environmental pollution.

  7. Specific estrogen-induced cell proliferation of cultured Syrian hamster renal proximal tubular cells in serum-free chemically defined media

    International Nuclear Information System (INIS)

    Oberley, T.D.; Lauchner, L.J.; Pugh, T.D.; Gonzalez, A.; Goldfarb, S.; Li, S.A.; Li, J.J.

    1989-01-01

    It has long been recognized that the renal proximal tubular epithelium of the hamster is a bona fide estrogen target tissue. The effect of estrogens on the growth of proximal tubule cell explants and dissociated single cells derived from these explant outgrowths has been studied in culture. Renal tubular cells were grown on a PF-HR-9 basement membrane under serum-free chemically defined culture conditions. At 7-14 days in culture, cell number was enhanced 3-fold in the presence of either 17β-estradiol or diethylstilbestrol. A similar 3-fold increase in cell number was also seen at 1 nM 17β-estradiol in subcultured dissociated single tubular cells derived from hamster renal tubular explant outgrowths at 21 days in culture. Concomitant exposure of tamoxifen at 3-fold molar excess in culture completely abolished the increase in cell number seen with 17β-estradiol. The proliferation effect of estrogens on proximal tubular cell growth appears to be species specific since 17β-estradiol did not alter the growth of either rat or guinea pig proximal tubules in culture. In addition, at 7-10 days in culture in the presence of 17β-estradiol, [ 3 H]thymidine labeling of hamster tubular cells was enhanced 3-fold. These results clearly indicate that estrogens can directly induce primary epithelial cell proliferation at physiologic concentrations and provide strong additional evidence for an important hormonal role in the neoplastic transformation of the hamster kidney

  8. Kas poliitiline fair play on võimalik? / Juhan Kivirähk

    Index Scriptorium Estoniae

    Kivirähk, Juhan, 1957-

    2001-01-01

    Sotisoloog Juhan Kivirähk valimiskampaaniatest, presidendi valimise korrast. Mis saaks siis kui valimised läheksid tagasi Riigikokku? Diagrammid: Valijameeste ja rahva soosikud ; Rahva eelistused ajas

  9. Turvajalkineiden vaikutus jalkaterveyteen Suur-Savon Sähkötyö Oy:ssä

    OpenAIRE

    Pulkkinen, Riikka; Tossavainen, Inka; Ryynänen, Elina

    2014-01-01

    Opinnäytetyön tarkoituksena oli selvittää, millaisia vaikutuksia turvajalkineilla voi olla jalkaterveyteen, minkälaisia jalkaongelmia turvajalkineiden käyttö voi aiheuttaa, voivatko työntekijät itse vaikuttaa turvajalkineiden hankintaan ja millainen on turvajalkineiden hankintaprosessi Suur-Savon Sähkötyö Oy:ssä. Opinnäytetyömme toimeksiantaja oli Suur-Savon Sähkötyö Oy. Tutkimusmenetelmänä käytettiin pääasiassa kvantitatiivista tutkimusta ja aineisto kerättiin puolistrukturoidulla kysely...

  10. Antioxidant Effects of Selenium on Seminiferous Tubules of Immature Mice Testis

    Directory of Open Access Journals (Sweden)

    Davoud Kushki

    2015-12-01

    Full Text Available Background: The freezing of immature testis tissue and then the transplant of it can be considered as a major step in fertility preservation for young boys with cancer, the survival of animal generation exposed to extinction and cloning animalistic desirable species. One of the most prevalent of damages in during the freezing-thawing process is oxidative stress. Objectives: The objective of this study was to investigate the antioxidant effects of selenium compound (Na2SeO3 on rate of seminiferous tubules injury in during of cryopreservation. Materials and Methods: In this experimental study, 8 BALB/c immature male mice (6 - 8 days old were randomly selected, and the testes removed surgically (n = 16. The testes divided into 2 groups: experimental group, control group (opposite testes. For each of the two experimental and control groups, two types of soluble (freezing solution and thawing solution were prepared. These solutions, which contain 2 mg/mL solution of Na2SeO3 and control solution, were prepared in the DMEM (Dulbecco’s modified eagle medium base medium. Of each group were 4 testes into fast freezing-thawing procedure and 4 testes were into slow freezing-thawing procedure. Then this testis for analyzing injury, after preparatory process, was stained with hematoxylin-eosin. Results: At the slow freezing-thawing procedure, seminiferous tubules injury significantly reduced in experimental group compared to control group. At the fast freezing-thawing procedure, seminiferous tubules injury significantly reduced in experimental group compared with of control group. Conclusions: It seems that Se due to its antioxidant properties, the harmful effects of freezing-thawing process reduces and protects seminiferous tubules from oxidative injury.

  11. Wild boars (Sus scrofa scrofa seminiferous tubules morphometry

    Directory of Open Access Journals (Sweden)

    Deiler Sampaio Costa

    2006-09-01

    Full Text Available The aim of this data was to analyze morphology and function of the seminiferous tubule in adult wild boars. Testes removed by unilateral castration of five animals were used. The testicular parenchyma was composed by 82.1±2.2% of seminiferous tubule and 17.9±2.2% of intertubular tissue. The tubular diameter was 249.2±33.0 µm and the seminiferous tubule lenght per gram of testis was 19.3±4.9m. The spermatogonial mitoses efficiency coefficient, meiotic index and spermatogenesis efficiency were 10.34, 2.71 and 30.5 respectively. Each Sertoli cell supported about 13 germinatives cells. The hystometric parameters studied were very similar to those related for domestic boars, however, the wild boars intrinsic efficiency of spermatogenesis and Sertoli cells indexes were smaller than in domestic boars.Objetivou-se com esta pesquisa estudar as características morfométricas e funcionais dos túbulos seminíferos de javalis adultos. Utilizaram-se testículos de cinco animais submetidos a orquiectomia unilateral. O parênquima testicular foi composto por 82,1 ± 2,2% de túbulos seminíferos e 17,9 ± 2,2% de tecido intertubular. O diâmetro tubular foi de 249,2 ± 33,0µm e o comprimento dos túbulos seminíferos por grama de testículo foi de 19,3 ± 4,9m. O coeficiente de eficiência das mitoses espermatogônias, o rendimento meiótico e o rendimento geral da espermatogênese foram, respectivamente, 10,34, 2,71 e 30,50. Cada célula de Sértoli suportou cerca de 13 células germinativas. Conclui-se que os parâmetros histométricos estudados nesta pesquisa foram muito semelhantes aos valores relatados para suínos domésticos, entretanto, o rendimento intrínseco da espermatogênese e os índices de células de Sértoli de javalis foram relativamente baixos quando comparados com aqueles animais.

  12. Measurements of Hk and Ms in thin magnetic films by the angular dependence of the planar Hall effect

    Science.gov (United States)

    Vatskicheva, M.; Vatskichev, L.

    1987-11-01

    It is shown that the angular dependences of the planar Hall effect measured with infinite magnetic field and with magnetic field H⩾ Hk have an intersection point and this fact is enough for measuring the anisotropy field Hk applying the method presented by Pastor, Ferreiro and Torres in J. Magn. Magn. Mat. 53 (1986) 349, 62 (1986) 101. The scaling of the Hall tension U proportional to M2s in mV/Am -1 gives a possibility for calculating the Ms-values of the films. These assumptions are verified for NiFe- and NiFeGe films with a uniaxial magnetic anisotropy.

  13. Evidence for a role of claudin 2 as a proximal tubular stress responsive paracellular water channel

    Energy Technology Data Exchange (ETDEWEB)

    Wilmes, Anja, E-mail: Anja.Wilmes@i-med.ac.at; Aschauer, Lydia; Limonciel, Alice; Pfaller, Walter; Jennings, Paul

    2014-09-01

    Claudins are the major proteins of the tight junctions and the composition of claudin subtypes is decisive for the selective permeability of the paracellular route and thus tissue specific function. Their regulation is complex and subject to interference by several factors, including oxidative stress. Here we show that exposure of cultured human proximal tubule cells (RPTEC/TERT1) to the immunosuppressive drug cyclosporine A (CsA) induces an increase in transepithelial electrical resistance (TEER), a decrease in dome formation (on solid growth supports) and a decrease in water transport (on microporous growth supports). In addition, CsA induced a dramatic decrease in the mRNA for the pore forming claudins -2 and -10, and the main subunits of the Na{sup +}/K{sup +} ATPase. Knock down of claudin 2 by shRNA had no discernable effect on TEER or dome formation but severely attenuated apical to basolateral water reabsorption when cultured on microporous filters. Generation of an osmotic gradient in the basolateral compartment rescued water transport in claudin 2 knock down cells. Inhibition of Na{sup +}/K{sup +} ATPase with ouabain prevented dome formation in both cell types. Taken together these results provide strong evidence that dome formation is primarily due to transcellular water transport following a solute osmotic gradient. However, in RPTEC/TERT1 cells cultured on filters under iso-osmotic conditions, water transport is primarily paracellular, most likely due to local increases in osmolarity in the intercellular space. In conclusion, this study provides strong evidence that claudin 2 is involved in paracellular water transport and that claudin 2 expression is sensitive to compound induced cellular stress. - Highlights: • Cyclosporine A increased TEER and decreased water transport in RPTEC/TERT1 cells. • Claudins 2 and 10 were decreased in response to cyclosporine A. • Knock down of claudin 2 inhibited water transport in proximal tubular cells. • We

  14. Glucose dynamics and mechanistic implications of SGLT2 inhibitors in animals and humans.

    Science.gov (United States)

    List, James F; Whaley, Jean M

    2011-03-01

    Glucose is freely filtered in the glomeruli before being almost entirely reabsorbed into circulation from the proximal renal tubules. The sodium-glucose cotransporter 2 (SGLT2), present in the S1 segment of the proximal tubule, is responsible for the majority of glucose reabsorption. SGLT2 inhibitors reduce glucose reabsorption and increase urinary glucose excretion. In animal models and humans with type 2 diabetes, this effect is associated with reduced fasting and postprandial blood glucose levels, and reduced hemoglobin A1c. Animal studies suggest that reduction of hyperglycemia with SGLT2 inhibitors may also improve insulin sensitivity and preserve β-cell function. Urinary excretion of excess calories with SGLT2 inhibitors is also associated with reduction in body weight. Modest reductions in blood pressure have been noted with SGLT2 inhibitors, consistent with a mild diuretic action. Some C-glucoside SGLT2 inhibitors, such as dapagliflozin, have pharmacokinetic properties that make them amenable to once-daily dosing.

  15. Recombinant human GLP-1(rhGLP-1) alleviating renal tubulointestitial injury in diabetic STZ-induced rats.

    Science.gov (United States)

    Yin, Weiqin; Xu, Shiqing; Wang, Zai; Liu, Honglin; Peng, Liang; Fang, Qing; Deng, Tingting; Zhang, Wenjian; Lou, Jinning

    2018-01-01

    GLP-1-based treatment improves glycemia through stimulation of insulin secretion and inhibition of glucagon secretion. Recently, more and more findings showed that GLP-1 could also protect kidney from diabetic nephropathy. Most of these studies focused on glomeruli, but the effect of GLP-1 on tubulointerstitial and tubule is not clear yet. In this study, we examined the renoprotective effect of recombinant human GLP-1 (rhGLP-1), and investigated the influence of GLP-1 on inflammation and tubulointerstitial injury using diabetic nephropathy rats model of STZ-induced. The results showed that rhGLP-1 reduced urinary albumin without influencing the body weight and food intake. rhGLP-1 could increased the serum C-peptide slightly but not lower fasting blood glucose significantly. In diabetic nephropathy rats, beside glomerular sclerosis, tubulointerstitial fibrosis was very serious. These lesions could be alleviated by rhGLP-1. rhGLP-1 decreased the expression of profibrotic factors collagen I, α-SMA, fibronectin, and inflammation factors MCP-1 and TNFα in tubular tissue and human proximal tubular cells (HK-2 cells). Furthermore, rhGLP-1 significantly inhibited the phosphorylation of NF-κB, MAPK in both diabetic tubular tissue and HK-2 cells. The inhibition of the expression of TNFα, MCP-1, collagen I and α-SMA in HK-2 cells by GLP-1 could be mimicked by blocking NF-κB or MAPK. These results indicate that rhGLP-1 exhibit renoprotective effect by alleviation of tubulointerstitial injury via inhibiting phosphorylation of MAPK and NF-κB. Therefore, rhGLP-1 may be a potential drug for treatment of diabetic nephropathy. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Metabolism of cysteine and cysteinesulfinate in rat kidney tubules

    International Nuclear Information System (INIS)

    De La Rosa, J.; Stipanuk, M.H.

    1986-01-01

    In studies with rat hepatocytes, hypotaurine plus taurine production accounted for less than 5% of the total amount of cysteine (CYS) catabolized, whereas more than 90% of the metabolized cysteinesulfinate (CSA) was converted to taurine plus hypotaurine. Similar studies have been carried out with kidney tubules isolated from fed rats and incubated with 2 mM [1- 14 C]CYS or 25 mM [1- 14 C]CSA at 37 0 C for up to 40 min. The production of 14 CO 2 from CSA (3.1 +/- 1.3 nmol/sup ./ min -1 /sup ./ mg dry wt -1 ) was equivalent to the accumulation of N in NH 4 + plus glutamate. Substantial oxidation of CYS was observed (16 +/- 11 nmol CO 2 x min -1 x mg dry wt -1 ), but only 12% of the expected amount of N was recovered as NH 4 + plus glutamate. Accumulation of hypotaurine plus taurine was equivalent to 20% of the observed rate of 14 CO 2 production from CSA but accounted for only 2% of the observed rate of 14 CO 2 production from CYS. Addition of unlabeled CSA to incubations with varying levels of CYS had no effect on production of 14 CO 2 . Addition of 2 mM α-ketoglutarate to the incubation mixtures resulted in an increased in 14 CO 2 production from CSA to 290% of the control level but had no effect on CYS oxidation. In agreement with the authors findings for rat hepatocytes, these data suggest that most metabolism of CYS by the rat kidney tubule occurs by a CSA-independent pathway. However, in contrast to the metabolism of CSA almost entirely to taurine in the hepatocyte, kidney tubules appeared to metabolize CSA primarily by the transamination pathway

  17. Chemically triggered ejection of membrane tubules controlled by intermonolayer friction.

    Science.gov (United States)

    Fournier, J-B; Khalifat, N; Puff, N; Angelova, M I

    2009-01-09

    We report a chemically driven membrane shape instability that triggers the ejection of a tubule growing exponentially toward a chemical source. The instability is initiated by a dilation of the exposed monolayer, which is coupled to the membrane spontaneous curvature and slowed down by intermonolayer friction. Our experiments are performed by local delivery of a basic pH solution to a giant vesicle. Quantitative fits of the data give an intermonolayer friction coefficient b approximately 2x10;{9} J s/m;{4}. The exponential growth of the tubule may be explained by a Marangoni stress yielding a pulling force proportional to its length.

  18. FlnA binding to PACSIN2 F-BAR domain regulates membrane tubulation in megakaryocytes and platelets.

    Science.gov (United States)

    Begonja, Antonija Jurak; Pluthero, Fred G; Suphamungmee, Worawit; Giannini, Silvia; Christensen, Hilary; Leung, Richard; Lo, Richard W; Nakamura, Fumihiko; Lehman, William; Plomann, Markus; Hoffmeister, Karin M; Kahr, Walter H A; Hartwig, John H; Falet, Hervé

    2015-07-02

    Bin-Amphiphysin-Rvs (BAR) and Fes-CIP4 homology BAR (F-BAR) proteins generate tubular membrane invaginations reminiscent of the megakaryocyte (MK) demarcation membrane system (DMS), which provides membranes necessary for future platelets. The F-BAR protein PACSIN2 is one of the most abundant BAR/F-BAR proteins in platelets and the only one reported to interact with the cytoskeletal and scaffold protein filamin A (FlnA), an essential regulator of platelet formation and function. The FlnA-PACSIN2 interaction was therefore investigated in MKs and platelets. PACSIN2 associated with FlnA in human platelets. The interaction required FlnA immunoglobulin-like repeat 20 and the tip of PACSIN2 F-BAR domain and enhanced PACSIN2 F-BAR domain membrane tubulation in vitro. Most human and wild-type mouse platelets had 1 to 2 distinct PACSIN2 foci associated with cell membrane GPIbα, whereas Flna-null platelets had 0 to 4 or more foci. Endogenous PACSIN2 and transfected enhanced green fluorescent protein-PACSIN2 were concentrated in midstage wild-type mouse MKs in a well-defined invagination of the plasma membrane reminiscent of the initiating DMS and dispersed in the absence of FlnA binding. The DMS appeared less well defined, and platelet territories were not readily visualized in Flna-null MKs. We conclude that the FlnA-PACSIN2 interaction regulates membrane tubulation in MKs and platelets and likely contributes to DMS formation. © 2015 by The American Society of Hematology.

  19. Natural history of seminiferous tubule degeneration in Klinefelter syndrome

    DEFF Research Database (Denmark)

    Aksglaede, Lise; Wikström, Anne M; Rajpert-De Meyts, Ewa

    2006-01-01

    Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates dramatic......Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates...... summarize current knowledge on the development of the classical endocrinological and histological features of 47,XXY males from fetus to adulthood and review the literature concerning the degeneration of the seminiferous tubules in this syndrome....

  20. hköalan oppimateriaalin verkkodokumentointi

    OpenAIRE

    Riikonen, Timitri

    2015-01-01

    Tämän työn tavoitteena oli kehittää Savonia-ammattikorkeakoulun sähköalan opetuksen verkkodokumentointia. Työssä luodaan alusta, jota käytetään kurssin ohella. Alustaan tulisi sisällyttää sekä kurssimateriaali, että kurssin aikana käsiteltyjen asioiden havainnollistava materiaali. Sen tulisi olla helppo sekä käyttää että muokata. Alustaa varten testattiin useita eri sovelluksia. Työssä käytettiin Savonia-ammattikorkeakoululla käytössä olevaa DMS600NE-verkkotietojärjestelmää. Ohjelmaan luo...

  1. In vivo model for microbial invasion of tooth root dentinal tubules

    Directory of Open Access Journals (Sweden)

    Jane L. BRITTAN

    2016-04-01

    Full Text Available ABSTRACT Objective Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity. Material and Methods Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF. DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database. Results All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0 to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents. Conclusion A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine.

  2. Mycelial fermentation and medicinal properties of a valuable medicinal fungus Cordyceps sinensis Cs-HK1

    Institute of Scientific and Technical Information of China (English)

    Wu Jianyong

    2014-01-01

    Cordyceps sinensis (Cs) or Dongchongxiacao in Chinese is a rare and precious medicinal mushroom. In this work,a Tolypocladium sp. fungus named Cs-HK1 was isolated from a natural Cs fruiting body,and its ultraviolet (UV),infrared (IR) and high-performance liquid chromatography(HPLC) spectra all exhibited high degrees of matching to those of natural Cs,indicating the similarity of chemical composition. A crude polysac-charide (PS) fraction isolated from Cs-HK1 fungal mycelium showed significant antitumor activity,inhibiting melanoma tumor growth in mice. The PS-treated mice showed significantly higher serum interferon-γ(IFN-γ) level and higher proliferation rate of lymphocytes ex vivo than the control animals,suggestive of the immuno-modulatory activity of the PS fraction. In cell cultures,the PS fraction caused a significant and dose-dependent inhibitory effect on the proliferation of two cancer cell lines ,B16/neu mouse melanoma and MDA-MB-231 human breast cancer cells,but not on normal spleen lymphocytes in vitro. Most of these bioactivities of the Cs-HK1 fungus were comparable to or even greater than those of natural Cs. The results showed that Cs-HK1 fun-gus may be a functional substitute for the natural Cs in health food and herbal medicine.

  3. In Vitro Evaluation of Dentin Tubule Occlusion for Novel Calcium Lactate Phosphate (CLP Paste

    Directory of Open Access Journals (Sweden)

    Jen-Chang Yang

    2017-02-01

    Full Text Available Introduction: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP based desensitizing agent. Methods: Dentin disks (n = 9 were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate® Pro-Relief™ paste, CLP paste, and double distilled water (ddH2O by a rubber-cupped handpiece. Dentin disks were analyzed under optical micrographs for pre-treatment, directly after treatment, and 14 days post-treatment. One-way ANOVA and post-hoc Tukey’s test were used to determine whether there were any statistically significant differences in dentinal tubule diameter. Results: A significant decrease occurred in the mean tubule diameter for dentin disks treated with CLP paste. A decrease was observed from 3.52 ± 0.83 µm to 2.62 ± 0.42 µm right after treatment, further decreasing to 1.71 ± 0.45 µm after immersion in artificial saliva for 14 days (p < 0.05. Conclusions: The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion.

  4. hköisen kaupankäynnin kehittäminen : Case Arkmedian verkkokauppa

    OpenAIRE

    Lampimäki, Tami

    2014-01-01

    hköinen kaupankäynti on muuttanut kuluttajien ja yritysasiakkaitten tapaa tehdä ostoksia ja tilauksia. Tänä päivänä lähes jokaisella yrityksellä on kotisivut, joista löytyvät yhteystiedot ja muuta oleellista tietoa yrityksestä. Myös verkkokauppa on tullut osaksi kuluttajien ja yritysasiakkaitten välistä kaupankäyntiä. Työssäni selvitän mistä ominaisuuksista koostuu tuottava ja toimiva verkkokauppa. Kun yritys aloittaa sähköiseen kaupankäynnin tulisi pohtia tavoitteita, mitä yritys haluaa...

  5. Analysis of efficacy of SGLT2 inhibitors using semi-mechanistic model

    Directory of Open Access Journals (Sweden)

    Oleg eDemin Jr

    2014-10-01

    Full Text Available Renal sodium-dependent glucose co-transporter 2 (SGLT2 is one of the most promising targets for the treatment of type 2 diabetes. Two SGLT2 inhibitors, dapagliflozin and canagliflozin, have already been approved for use in USA and Europe; several additional compounds are also being developed for this purpose. Based on the in vitro IC50 values and plasma concentration of dapagliflozin measured in clinical trials, the marketed dosage of the drug was expected to almost completely inhibit SGLT2 function and reduce glucose reabsorption by 90%. However, the administration of dapagliflozin resulted in only 30–50% inhibition of reabsorption. This study was aimed at investigating the mechanism underlying the discrepancy between the expected and observed levels of glucose reabsorption. To this end, systems pharmacology models were developed to analyze the time profile of dapagliflozin, canagliflozin, ipragliflozin, empagliflozin, and tofogliflozin in the plasma and urine; their filtration and active secretion from the blood to the renal proximal tubules; reverse reabsorption; urinary excretion; and their inhibitory effect on SGLT2. The model shows that concentration levels of tofogliflozin, ipragliflozin, and empagliflozin are higher than levels of other inhibitors following administration of marketed SGLT2 inhibitors at labeled doses and non-marketed SGLT2 inhibitors at maximal doses (approved for phase 2/3 studies. All the compounds exhibited almost 100% inhibition of SGLT2. Based on the results of our model, two explanations for the observed low efficacy of SGLT2 inhibitors were supported: 1 the site of action of SGLT2 inhibitors is not in the lumen of the kidney’s proximal tubules, but elsewhere (e.g., the kidneys proximal tubule cells; and 2 there are other transporters that could facilitate glucose reabsorption under the conditions of SGLT2 inhibition (e.g., other transporters of SGLT family.

  6. URG11 mediates hypoxia-induced epithelial-to-mesenchymal transition by modulation of E-cadherin and β-catenin

    International Nuclear Information System (INIS)

    Du, Rui; Huang, Chen; Bi, Qian; Zhai, Ying; Xia, Lin; Liu, Jie; Sun, Shiren; Fan, Daiming

    2010-01-01

    Upregulated gene 11 (URG11), recently identified as a new HBx-upregulated gene that may activate β-catenin and Wnt signaling, was found to be upregulated in a human tubule cell line under low oxygen. Here, we investigated the potential role of URG11 in hypoxia-induced renal tubular epithelial-to-mesenchymal (EMT). Overexpression of URG11 in a human proximal tubule cell line (HK2) promoted a mesenchymal phenotype accompanied by reduced expression of the epithelial marker E-cadherin and increased expression of the mesenchymal markers vimentin and α-SMA, while URG11 knockdown by siRNA effectively reversed hypoxia-induced EMT. URG11 promoted the expression of β-catenin and increased its nuclear accumulation under normoxic conditions through transactivation of the β-catenin promoter. This in turn upregulated β-catenin/T-cell factor (TCF) and its downstream effector genes, vimentin, and α-SMA. In vivo, strong expression of URG11 was observed in the tubular epithelia of 5/6-nephrectomized rats, and a Western blot analysis demonstrated a close correlation between HIF-1α and URG11 protein levels. Altogether, our results indicate that URG11 mediates hypoxia-induced EMT through the suppression of E-cadherin and the activation of the β-catenin/TCF pathway.

  7. Analysis of the efficacy of SGLT2 inhibitors using semi-mechanistic model

    Science.gov (United States)

    Demin, Oleg; Yakovleva, Tatiana; Kolobkov, Dmitry; Demin, Oleg

    2014-01-01

    The Renal sodium-dependent glucose co-transporter 2 (SGLT2) is one of the most promising targets for the treatment of type 2 diabetes. Two SGLT2 inhibitors, dapagliflozin, and canagliflozin, have already been approved for use in USA and Europe; several additional compounds are also being developed for this purpose. Based on the in vitro IC50 values and plasma concentration of dapagliflozin measured in clinical trials, the marketed dosage of the drug was expected to almost completely inhibit SGLT2 function and reduce glucose reabsorption by 90%. However, the administration of dapagliflozin resulted in only 30–50% inhibition of reabsorption. This study was aimed at investigating the mechanism underlying the discrepancy between the expected and observed levels of glucose reabsorption. To this end, systems pharmacology models were developed to analyze the time profile of dapagliflozin, canagliflozin, ipragliflozin, empagliflozin, and tofogliflozin in the plasma and urine; their filtration and active secretion from the blood to the renal proximal tubules; reverse reabsorption; urinary excretion; and their inhibitory effect on SGLT2. The model shows that concentration levels of tofogliflozin, ipragliflozin, and empagliflozin are higher than levels of other inhibitors following administration of marketed SGLT2 inhibitors at labeled doses and non-marketed SGLT2 inhibitors at maximal doses (approved for phase 2/3 studies). All the compounds exhibited almost 100% inhibition of SGLT2. Based on the results of our model, two explanations for the observed low efficacy of SGLT2 inhibitors were supported: (1) the site of action of SGLT2 inhibitors is not in the lumen of the kidney's proximal tubules, but elsewhere (e.g., the kidneys proximal tubule cells); and (2) there are other transporters that could facilitate glucose reabsorption under the conditions of SGLT2 inhibition (e.g., other transporters of SGLT family). PMID:25352807

  8. Accumulation of enriched uranium UO2F2 in ultrastructure as studied by electron microscopic autoradiography

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Wang Yuanchang

    1992-01-01

    A study was made on the retention of soluble enriched uranium UO 2 F 2 in ultrastructure by electron microscopic autoradiography. The early dynamic accumulation of radioactivity in the body showed that enriched uranium UO 2 F 2 was mainly localized in kidneys, especially accumulated in epithelial cells of proximal convoluted tubules leading to degeneration and necrosis of the tubules. In liver cells, enriched uranium UO 2 F 2 at first deposited in nuclei of the cells and in soluble proteins of the plasma, and later accumulated selectively in mitochondria and lysosomes. On electron microscopic autoradiographic study it was shown that the dynamic retention of radioactivity of enriched uranium UO 2 F 2 in skeleton increased steadily through the time period of exposure. Enriched uranium UO 2 F 2 chiefly deposited in nuclei and mitochondria of osteoblasts as well as of osteoclasts

  9. Identification of Human HK Genes and Gene Expression Regulation Study in Cancer from Transcriptomics Data Analysis

    Science.gov (United States)

    Zhang, Zhang; Liu, Jingxing; Wu, Jiayan; Yu, Jun

    2013-01-01

    The regulation of gene expression is essential for eukaryotes, as it drives the processes of cellular differentiation and morphogenesis, leading to the creation of different cell types in multicellular organisms. RNA-Sequencing (RNA-Seq) provides researchers with a powerful toolbox for characterization and quantification of transcriptome. Many different human tissue/cell transcriptome datasets coming from RNA-Seq technology are available on public data resource. The fundamental issue here is how to develop an effective analysis method to estimate expression pattern similarities between different tumor tissues and their corresponding normal tissues. We define the gene expression pattern from three directions: 1) expression breadth, which reflects gene expression on/off status, and mainly concerns ubiquitously expressed genes; 2) low/high or constant/variable expression genes, based on gene expression level and variation; and 3) the regulation of gene expression at the gene structure level. The cluster analysis indicates that gene expression pattern is higher related to physiological condition rather than tissue spatial distance. Two sets of human housekeeping (HK) genes are defined according to cell/tissue types, respectively. To characterize the gene expression pattern in gene expression level and variation, we firstly apply improved K-means algorithm and a gene expression variance model. We find that cancer-associated HK genes (a HK gene is specific in cancer group, while not in normal group) are expressed higher and more variable in cancer condition than in normal condition. Cancer-associated HK genes prefer to AT-rich genes, and they are enriched in cell cycle regulation related functions and constitute some cancer signatures. The expression of large genes is also avoided in cancer group. These studies will help us understand which cell type-specific patterns of gene expression differ among different cell types, and particularly for cancer. PMID:23382867

  10. Effects of intravenous bumetanide administration on renal haemodynamics and proximal and distal tubular sodium reabsorption in conscious rats

    Energy Technology Data Exchange (ETDEWEB)

    Shalmi, M.; Petersen, J.S.; Christensen, S. (Department of pharmacology, University of Copenhagen (Denmark))

    1989-01-01

    The renal effects of 0.02-62.5 mg/kg bumetanide given as intravenous bolus injections were studied in water diuretic conscious rats. Clearances of {sup 14}C-tetraethylammonium, {sup 3}H-inulin and lithium were used as markers for renal plasma flow (RPF), glomerular filtion rate (GFR) and proximal tubular output, respectively. Bumetanide caused biphasic, transient and dose-independent changes in the renal haemodynamics without significant alterations of the filtration fraction. At dose-levels above 0.02 mg/kg bumetanide increased urine flow, absolute and fractional Na excretion as well as the indices for fractional output of Na from the proximal tubules (C{sub Li}/C{sub I}n) and the distal nephron segments (C{sub Na}/C{sub Li}). The changes in C{sub Li}/C{sub In} became maximal at doses above 0.5 mg/kg, whereas C{sub Na}/C{sub Li} was increased with the dose up to 12.5 mg/kg. Paradoxically, doses above 12.5 mg/kg were less natriuretic due to a decrease of C{sub Na}/C{sub Li}. It is concluded that in rats bumetanide is an effective although short-acting diuretic when administered intravenously. When comparing peak responses bumetanide is equipotent to furosemide but has a lower maximal efficacy. Judged from the changes in fractional lithium excretion, the natriuretic effect of bumetanide is effected by inhibition of Na reabsorption in the proximal tubule in addition to the well-known effect on the distal nephron segment. (author).

  11. hköinen asiointi tavaraliikennelupahakemuksen toimintaprosessissa

    OpenAIRE

    Laitakari, Pauliina

    2012-01-01

    Korvausta vastaan suoritettavaan tavarankuljetukseen tarvitaan voimassaoleva tavaraliikennelupa, jonka myöntää Elinkeino-, liikenne- ja ympäristökeskus. Opinnäytetyön toimeksiantajana on Pohjois-Pohjanmaan Elinkeino-, liikenne- ja ympäristökeskus. Työ tehdään liikenne ja infrastruktuuri –vastuualueen lupapalvelut-yksikköön. Opinnäytetyön aiheena on sähköinen asiointi tavaraliikenneluvan toimintaprosessissa. Lakimuutosten myötä lisääntyneet työtehtävät vaativat toiminnan tehostamista ja tämän ...

  12. Puuluodon sähkönjakeluverkon saneeraus

    OpenAIRE

    Huhta, Heidi

    2011-01-01

    Tämän opinnäytetyön tarkoituksena oli suunnitella Puuluodon sähkönjakeluverkon saneeraus, jossa alueen pien- ja keskijänniteverkon sekä katuvalaistuksen ilmajohdot tuli korvata maakaapeleilla. Alueella olevat pylväsmuuntamot tuli myös korvata tarvittavalla määrällä puistomuuntamoita. Suunnitelma tehtiin käyttäen Teklan Xpower-verkostolaskentaohjelmaa. Lisäksi työhön kuului työn kustannusten arviointi Energiamarkkinaviraston hintojen mukaan. Työn teoriaosassa käytiin läpi suunnitteluun li...

  13. Studies of a genetic variant in HK1 in relation to quantitative metabolic traits and to the prevalence of type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Bonnefond Amélie

    2011-07-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs within the gene encoding Hexokinase 1 (HK1 are associated with changes in glycated haemoglobin (HbA1c levels. Our aim was to investigate the effect of HK1 rs7072268 on measures of glucose- and lipid-metabolism in a Danish non-diabetic population and combine the outcome of these analyses in a meta-analysis with previously published results. Furthermore, our aim was to perform a type 2 diabetes case-control analysis and meta-analysis with two previous case-control studies. Methods SNP rs7072268 was genotyped in 9,724 Danes. The quantitative trait study included 5,604 non-diabetic individuals from the Inter99 cohort. The case-control study included 4,449 glucose tolerant individuals and 3,398 patients with type 2 diabetes. Meta-analyses on quantitative traits included 24,560 Caucasian individuals and 30,802 individuals were included in the combined analysis of present and previous type 2 diabetes case-control studies. Results Using an additive model, we confirmed that the T-allele of rs7072268 associates with increased HbA1c of 0.6% (CI: 0.4 - 0.9, p = 3*10-7 per allele. The same allele associated with an increased area under the curve (AUC for glucose of 5.0 mmol/l*min (0.1 - 10.0, p = 0.045 following an oral glucose tolerance test (OGTT and increased fasting levels of cholesterol of 0.06 mmol/l (0.03 - 1.0, p = 0.001 and triglycerides of 2.0% (0.2 - 3.8, p = 0.03 per allele in the same study sample of non-diabetic individuals from the Inter99 cohort. However, the T-allele did not show any association with estimates of insulin release or insulin sensitivity neither in Inter99 nor in combined analyses. The prevalence of type 2 diabetes was increased among carriers of the rs7072268 T-allele both in the Danish study-population with an OR of 1.11 (1.02-1.21 and in a meta-analysis including the two additional sample sets with an OR of 1.06 (1.02-1.11. However, after Bonferroni correction the T

  14. Clinical Importance of Morphological Appearance of Seminiferous Tubules During MicroTESE in NOA Cases

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    A. H. Haliloglu

    2005-12-01

    Full Text Available Design: Clinical study. Setting: Research Center on Infertility, Ankara University; and Urology Department. Patients: 65 men with nonobstructive azoospermia (NOA.\tInterventions: Microscopical appearance of seminiferous tubules was recorded during TESE surgery. Differing from others, the largest opaque-white in color tubules were cut and removed. When all the tubules have no discriminating appearance, randomized biopsies were obtained. Removed tissue pieces were subjected to mechanical mincing under the stereomicroscope and then enzymatic digestion processes. Using inversion microscope (x32 magnification spermatozoa were searched. Main Outcome Measures: Morphological appearance of seminiferous tubules under optical magnification, spermatozoa recovery rates and histopathological findings were compared.\tRESULTS: In cases of Sertoli cell-only syndrome (SCOS, maturation arrest, hypospermatogenesis and focal spermatogenesis TESE yielded at least one spermatozoon in 37%, 52%, 100% and 63% of the cases, respectively. When all the seminiferous tubules were homogenously swollen, histopathological diagnosis was hypospermatogenesis in 100% of the cases. Homogenously thin and transparent tubules corresponded to SCOS or maturation arrest in 90% and 10% of the cases, respectively. Mature spermatozoa recovery rates were 100% and zero in homogenously-swollen observed and homogenously-thin observed tubules, respectively. CONCLUSIONS: Present data indicate that in cases of all tubules are homogenous in appearance and none of them can be discriminated from others, using microscope has no advantage in selection of the tubuli to be removed, but randomizely selection would also be sufficient. MicroTESE significantly increases the success in NOA cases with seminiferous tubules dispersed heterogeneously.

  15. Histological and three dimensional organizations of lymphoid tubules in normal lymphoid organ of Penaeus monodon.

    Science.gov (United States)

    Duangsuwan, Pornsawan; Phoungpetchara, Ittipon; Tinikul, Yotsawan; Poljaroen, Jaruwan; Wanichanon, Chaitip; Sobhon, Prasert

    2008-04-01

    The normal lymphoid organ of Penaeus monodon (which tested negative for WSSV and YHV) was composed of two parts: lymphoid tubules and interstitial spaces, which were permeated with haemal sinuses filled with large numbers of haemocytes. There were three permanent types of cells present in the wall of lymphoid tubules: endothelial, stromal and capsular cells. Haemocytes penetrated the endothelium of the lymphoid tubule's wall to reside among the fixed cells. The outermost layer of the lymphoid tubule was covered by a network of fibers embedded in a PAS-positive extracellular matrix, which corresponded to a basket-like network that covered all the lymphoid tubules as visualized by a scanning electron microscope (SEM). Argyrophilic reticular fibers surrounded haemal sinuses and lymphoid tubules. Together they formed the scaffold that supported the lymphoid tubule. Using vascular cast and SEM, the three dimensional structure of the subgastric artery that supplies each lobe of the lymphoid organ was reconstructed. This artery branched into highly convoluted and blind-ending terminal capillaries, each forming the lumen of a lymphoid tubule around which haemocytes and other cells aggregated to form a cuff-like wall. Stromal cells which form part of the tubular scaffold were immunostained for vimentin. Examination of the whole-mounted lymphoid organ, immunostained for vimentin, by confocal microscopy exhibited the highly branching and convoluted lymphoid tubules matching the pattern of the vascular cast observed in SEM.

  16. The mechanisms and therapeutic potential of SGLT2 inhibitors in diabetes mellitus.

    Science.gov (United States)

    Vallon, Volker

    2015-01-01

    The kidneys in normoglycemic humans filter 160-180 g of glucose per day (∼30% of daily calorie intake), which is reabsorbed and returned to the systemic circulation by the proximal tubule. Hyperglycemia increases the filtered and reabsorbed glucose up to two- to three-fold. The sodium glucose cotransporter SGLT2 in the early proximal tubule is the major pathway for renal glucose reabsorption. Inhibition of SGLT2 increases urinary glucose and calorie excretion, thereby reducing plasma glucose levels and body weight. The first SGLT2 inhibitors have been approved as a new class of antidiabetic drugs in type 2 diabetes mellitus, and studies are under way to investigate their use in type 1 diabetes mellitus. These compounds work independent of insulin, improve glycemic control in all stages of diabetes mellitus in the absence of clinically relevant hypoglycemia, and can be combined with other antidiabetic agents. By lowering blood pressure and diabetic glomerular hyperfiltration, SGLT2 inhibitors may induce protective effects on the kidney and cardiovascular system beyond blood glucose control.

  17. Natural history of seminiferous tubule degeneration in Klinefelter syndrome

    DEFF Research Database (Denmark)

    Aksglaede, Lise; Wikström, Anne M; Rajpert-De Meyts, Ewa

    2006-01-01

    Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates dramatic......Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates...

  18. Kivirähk, Pinter ja Inglise spioonid Rakvere teatris / Kristo Kruusman

    Index Scriptorium Estoniae

    Kruusman, Kristo

    2010-01-01

    Tänavu 70. sünnipäeva tähistava teatri repertuaaris on mitu uuslavastust: Andrus Kivirähk "Kaelkirjak", lavastaja Marion Undusk, Patrick Barlow’ spioonikomöödia „39 astet”, lavastaja Kati Kivitar ja Harold Pinteri näidend „Eikellegimaa”, lavastajaks Peeter Raudsepp

  19. Arkistointi tilitoimistossa : Siirtyminen sähköiseen arkistointiin

    OpenAIRE

    Parviainen, Pentti

    2014-01-01

    Arkistointi aiheuttaa monenlaisia haasteita tilitoimistoille. Tässä työssä pyritään kartoittamaan arkistoinnin järjestämistä toimeksiantajan tilitoimistossa. Toimeksiantajalle luodaan konkreettinen ehdotus/toimintamalli arkistoinnin järjestämisestä tulevaisuudessa. Työn erityisenä tarkastelun kohteena on sähköinen arkistointi, jolle kirjanpitolaki on antanut edellytykset jo vuodesta 1997. Toimeksiantajan nykyhetken kartoittamisen ohessa, joka toteutetaan haastattelujen avulla, tutustutaan ...

  20. Overendocytosis of gold nanoparticles increases autophagy and apoptosis in hypoxic human renal proximal tubular cells

    Directory of Open Access Journals (Sweden)

    Ding F

    2014-09-01

    Full Text Available Fengan Ding,1 Yiping Li,1 Jing Liu,1 Lei Liu,1 Wenmin Yu,1 Zhi Wang,1 Haifeng Ni,2 Bicheng Liu,2 Pingsheng Chen1,2 1School of Medicine, Southeast University, Nanjing, People’s Republic of China; 2Institute of Nephrology, The Affiliated Zhongda Hospital, Southeast University, Nanjing, People’s Republic of China Background: Gold nanoparticles (GNPs can potentially be used in biomedical fields ranging from therapeutics to diagnostics, and their use will result in increased human exposure. Many studies have demonstrated that GNPs can be deposited in the kidneys, particularly in renal tubular epithelial cells. Chronic hypoxic is inevitable in chronic kidney diseases, and it results in renal tubular epithelial cells that are susceptible to different types of injuries. However, the understanding of the interactions between GNPs and hypoxic renal tubular epithelial cells is still rudimentary. In the present study, we characterized the cytotoxic effects of GNPs in hypoxic renal tubular epithelial cells.Results: Both 5 nm and 13 nm GNPs were synthesized and characterized using various biophysical methods, including transmission electron microscopy, dynamic light scattering, and ultraviolet–visible spectrophotometry. We detected the cytotoxicity of 5 and 13 nm GNPs (0, 1, 25, and 50 nM to human renal proximal tubular cells (HK-2 by Cell Counting Kit-8 assay and lactate dehydrogenase release assay, but we just found the toxic effect in the 5 nm GNP-treated cells at 50 nM dose under hypoxic condition. Furthermore, the transmission electron microscopy images revealed that GNPs were either localized in vesicles or free in the lysosomes in 5 nm GNPs-treated HK-2 cells, and the cellular uptake of the GNPs in the hypoxic cells was significantly higher than that in normoxic cells. In normoxic HK-2 cells, 5 nm GNPs (50 nM treatment could cause autophagy and cell survival. However, in hypoxic conditions, the GNP exposure at the same condition led to the

  1. Jellyfish stinging is driven by the moving front of the nematocyst's tubule

    Science.gov (United States)

    Shavit, Uri; Park, Sinwook; Piriatinskiy, Gadi; Yossifon, Gilad; Lotan, Tamar

    2017-11-01

    Nematocysts are ultra-fast stinging organelles that are utilized by the Cnidaria phylum for prey capture, defense and locomotion. They consist of a capsule and a tubule and exert high pressure and acceleration to penetrate the target organism. Previous studies report that the ejection and elongation of the tubule are driven by a buildup of osmotic potential in the capsule. We question this explanation using a microfluidic system that controls the osmotic potential by directing the tubule through oil, where no osmotic potential can develop, while keeping the capsule in water. It was found that the time needed for elongation through oil is orders of magnitude larger than through water. Our mathematical model shows that the p γGlu concentration in the tubule is higher than in the capsule and the internal pressure that develops there serves as the elongation driving force. These findings imply that modifications of the environment along the tubule route have the potential to slow down the process and reduce its impact. This may shed light on prey defense strategies, human protection against jellyfish stinging, the use of nematocysts for drug delivery and exploration of osmotic based methods for nanotubes production and elongation.

  2. The persistent inhibitory properties of saxagliptin on renal dipeptidyl peptidase-4: Studies with HK-2 cells in vitro and normal rats in vivo

    Directory of Open Access Journals (Sweden)

    Masako Uchii

    2017-11-01

    Full Text Available Saxagliptin, a potent and selective DPP-4 inhibitor, exhibits a slow dissociation from DPP-4. We investigated the sustained effects of saxagliptin on renal DPP-4 activity in a washout study using renal tubular (HK-2 cells, and in a pharmacodynamic study using normal rats. In HK-2 cells, the inhibitory potency of saxagliptin on DPP-4 activity persisted after washout, while that of sitagliptin was clearly reduced. In normal rats, a single treatment of saxagliptin or sitagliptin inhibited the plasma DPP-4 activity to similar levels. The inhibitory action of saxagliptin on the renal DPP-4 activity was retained, even when its inhibitory effect on the plasma DPP-4 activity disappeared. However, the inhibitory action of sitagliptin on the renal DPP-4 activity was abolished in correlation with the inhibition of the plasma DPP-4 activity. In situ staining showed that saxagliptin suppressed the DPP-4 activity in both glomerular and tubular cells and its inhibitory effects were significantly higher than those of sitagliptin. Saxagliptin exerted a sustained inhibitory effect on the renal DPP-4 activity in vitro and in vivo. The long binding action of saxagliptin in renal tubular cells might involve the sustained inhibition of renal DPP-4.

  3. Role of CAP350 in centriolar tubule stability and centriole assembly.

    Directory of Open Access Journals (Sweden)

    Mikael Le Clech

    Full Text Available BACKGROUND: Centrioles are microtubule-based cylindrical structures composed of nine triplet tubules and are required for the formation of the centrosome, flagella and cilia. Despite theirs importance, centriole biogenesis is poorly understood. Centrosome duplication is initiated at the G1/S transition by the sequential recruitment of a set of conserved proteins under the control of the kinase Plk4. Subsequently, the procentriole is assembled by the polymerization of centriolar tubules via an unknown mechanism involving several tubulin paralogs. METHODOLOGY/PRINCIPAL FINDINGS: Here, we developed a cellular assay to study centrosome duplication and procentriole stability based on its sensitivity to the microtubule-depolymerizing drug nocodazole. By using RNA interference experiments, we show that the stability of growing procentrioles is regulated by the microtubule-stabilizing protein CAP350, independently of hSAS-6 and CPAP which initiate procentriole growth. Furthermore, our analysis reveals the critical role of centriolar tubule stability for an efficient procentriole growth. CONCLUSIONS/SIGNIFICANCE: CAP350 belongs to a new class of proteins which associate and stabilize centriolar tubules to control centriole duplication.

  4. Effects of SGLT2 inhibition in human kidney proximal tubular cells--renoprotection in diabetic nephropathy?

    Directory of Open Access Journals (Sweden)

    Usha Panchapakesan

    Full Text Available Sodium/glucose cotransporter 2 (SGLT2 inhibitors are oral hypoglycemic agents used to treat patients with diabetes mellitus. SGLT2 inhibitors block reabsorption of filtered glucose by inhibiting SGLT2, the primary glucose transporter in the proximal tubular cell (PTC, leading to glycosuria and lowering of serum glucose. We examined the renoprotective effects of the SGLT2 inhibitor empagliflozin to determine whether blocking glucose entry into the kidney PTCs reduced the inflammatory and fibrotic responses of the cell to high glucose. We used an in vitro model of human PTCs. HK2 cells (human kidney PTC line were exposed to control 5 mM, high glucose (HG 30 mM or the profibrotic cytokine transforming growth factor beta (TGFβ1; 0.5 ng/ml in the presence and absence of empagliflozin for up to 72 h. SGLT1 and 2 expression and various inflammatory/fibrotic markers were assessed. A chromatin immunoprecipitation assay was used to determine the binding of phosphorylated smad3 to the promoter region of the SGLT2 gene. Our data showed that TGFβ1 but not HG increased SGLT2 expression and this occurred via phosphorylated smad3. HG induced expression of Toll-like receptor-4, increased nuclear deoxyribonucleic acid binding for nuclear factor kappa B (NF-κB and activator protein 1, induced collagen IV expression as well as interleukin-6 secretion all of which were attenuated with empagliflozin. Empagliflozin did not reduce high mobility group box protein 1 induced NF-κB suggesting that its effect is specifically related to a reduction in glycotoxicity. SGLT1 and GLUT2 expression was not significantly altered with HG or empagliflozin. In conclusion, empagliflozin reduces HG induced inflammatory and fibrotic markers by blocking glucose transport and did not induce a compensatory increase in SGLT1/GLUT2 expression. Although HG itself does not regulate SGLT2 expression in our model, TGFβ increases SGLT2 expression through phosphorylated smad3.

  5. Beta-2 Microglobulin Kidney Disease Test

    Science.gov (United States)

    ... Diabetes Diarrhea Disseminated Intravascular Coagulation (DIC) Down Syndrome Ebola Virus Infection Endocrine System and Syndromes Epilepsy Excessive ... is then reabsorbed by the renal proximal tubules , structures that reclaim water, proteins, vitamins, minerals, and other ...

  6. Hierarchically assembled DNA origami tubules with reconfigurable chirality

    International Nuclear Information System (INIS)

    Chen, Haorong; Cha, Tae-Gon; Pan, Jing; Choi, Jong Hyun

    2013-01-01

    The dynamic reconfiguration of a hierarchically assembled tubular structure is demonstrated using the DNA origami technique. Short cylindrical DNA origami monomers are synthesized and linked into elongated tubules, which can then be disassembled via toehold-mediated strand displacement. The disassembled subunits are subsequently linked into tubules of a different chirality. The reconfiguration is performed with the subunits carrying dumbbell hairpin DNA oligonucleotides or gold nanoparticles (AuNPs). The reconfiguration of higher order origami structures presented here is useful for constructing dynamic nanostructures that exceed the size limit of single DNA origami and may facilitate the study of molecular or particle interactions by tuning their relative distance and organization. (paper)

  7. Annexin IV (Xanx-4) has a functional role in the formation of pronephric tubules.

    Science.gov (United States)

    Seville, Rachel A; Nijjar, Sarbjit; Barnett, Mark W; Massé, Karine; Jones, Elizabeth A

    2002-04-01

    Vertebrate kidney organogenesis is characterised by the successive formation of the pronephros, the mesonephros and the metanephros. The pronephros is the first to form and is the functional embryonic kidney of lower vertebrates; although it is vestigial in higher vertebrates, it is a necessary precursor for the other kidney types. The Xenopus pronephros is a simple paired organ; each nephron consists of a single large glomus, one set of tubules and a single duct. The simple organisation of the pronephros and the amenability of Xenopus laevis embryos to manipulation make the Xenopus pronephros an attractive system in which to study organogenesis. It has been shown that pronephric tubules can be induced to form in presumptive ectodermal tissue by treatment with RA and activin. We have used this system in a subtractive hybridisation screen that resulted in the cloning of Xenopus laevis annexin IV (Xanx-4). Xanx-4 transcripts are specifically located to the developing pronephric tubules, and the protein to the luminal surface of these tubules. Temporal expression shows zygotic transcription is upregulated at the time of pronephric tubule specification and persists throughout pronephric development. The temporal and spatial expression pattern of Xanx-4 suggests it may have a role in pronephric tubule development. Overexpression of Xanx-4 yields no apparent phenotype, but Xanx-4 depletion, using morpholinos, produces a shortened, enlarged tubule phenotype. The phenotype observed can be rescued by co-injection of Xanx-4 mRNA. Although the function of annexins is not yet clear, studies have suggested a role for annexins in a number of cellular processes. Annexin IV has been shown to have an inhibitory role in the regulation of epithelial calcium-activated chloride ion conductance. The enlarged pronephric tubule phenotype observed may be attributed to incorrect modulation of exocytosis, membrane plasticity or ion channels and/or water homeostasis. In this study, we

  8. High temperature corrosion kinetics study of IN-657 and HK-40 superalloys in contact with an 82% K[sub 2]S[sub 2]O[sub 7]-18% V[sub 2]O[sub 5] eutectic melt. Estudio de la cinetica de corrosion a alta temperatura de las superaleaciones IN-657 y HK-40 en presencia de la mezcla eutectica fundida 82% K[sub 2]S[sub 2]O[sub 7]-18% V[sub 2]O[sub 5

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A.; Otero, E.; Perez, F.J.; Alvarez, J.F.; Utrilla, M. V. (Universidad Complutense de Madrid (Spain). Facultad de Ciencias Quimicas)

    1993-01-01

    Electrochemical methods are used to study the corrosion kinetics of the IN-657 and HK-40 super-alloys in contact with the eutectic melt 82% K[sub 2]S[sub 2]O[sub 7]-18% V[sub 2]O[sub 5] with different carbon contents and at different temperatures (773 and 823 K). The results obtained are discussed in relation with the chemistry of the process. The kinetics equations of the corrosion process are given to the two super-alloys studied and at different test conditions. (Author) 18 refs.

  9. Cadmium transport by the gut and Malpighian tubules of Chironomus riparius

    International Nuclear Information System (INIS)

    Leonard, Erin M.; Pierce, Laura M.; Gillis, Patricia L.; Wood, Chris M.; O'Donnell, Michael J.

    2009-01-01

    Many aquatic insects are very insensitive to cadmium in short-term laboratory studies. LC50 values for larvae of the midge Chironomus riparius are over 25,000 times the Criterion Maximum Concentration in the United States Environmental Protection Agency (U.S. EPA (2000)) species sensitivity distribution (SSD). Excretion or sequestration of cadmium may contribute to insensitivity and we have therefore examined cadmium transport by isolated guts and renal tissues of C. riparius larvae. Regional differences of Cd transport along the gut were identified using a Cd 2+ -selective microelectrode in conjunction with the Scanning Ion-Selective Electrode Technique (SIET). Cd is transported into the anterior midgut (AMG) cells from the lumen and out of the cells into the hemolymph. The transport of Cd from the gut lumen to the hemolymph exposes other tissues such as the nervous system and muscles to Cd. The gut segments which remove Cd from the hemolymph at the highest rate are the posterior midgut (PMG) and the ileum. In addition, assays using an isolated Malpighian (renal) tubule preparation have shown that the Malpighian tubules (MT) both sequester and secrete Cd. For larvae bathed in 10 μmol l -1 Cd, the tubules can secrete the entire hemolymph burden of Cd in ∼15 h.

  10. Dentine tubule infection and endodontic therapy implications.

    Science.gov (United States)

    Oguntebi, B R

    1994-07-01

    A critical review of the literature suggests that the microenvironment of dentinal tubules appears to favour the selection of relatively few bacterial types irrespective of the aetiology of the infection process; coronal dental caries or pulpar necrosis. These bacteria may constitute an important reservoir from which root canal infection and reinfection may occur following pulp necrosis or during and after endodontic treatment. Previous studies of this microflora have utilized microbiological culture techniques which need to be supplemented by those that allow in situ demonstration as well as identification of the bacteria. Newer treatment strategies that are designed to eliminate this microflora must include agents that can penetrate the dentinal tubules and destroy these microorganisms, since they are located in an area beyond the host defence mechanisms where they cannot be reached by systemically administered antimicrobial agents.

  11. Characterization of Organic Anion Transporter 2 (SLC22A7): A Highly Efficient Transporter for Creatinine and Species-Dependent Renal Tubular Expression.

    Science.gov (United States)

    Shen, Hong; Liu, Tongtong; Morse, Bridget L; Zhao, Yue; Zhang, Yueping; Qiu, Xi; Chen, Cliff; Lewin, Anne C; Wang, Xi-Tao; Liu, Guowen; Christopher, Lisa J; Marathe, Punit; Lai, Yurong

    2015-07-01

    The contribution of organic anion transporter OAT2 (SLC22A7) to the renal tubular secretion of creatinine and its exact localization in the kidney are reportedly controversial. In the present investigation, the transport of creatinine was assessed in human embryonic kidney (HEK) cells that stably expressed human OAT2 (OAT2-HEK) and isolated human renal proximal tubule cells (HRPTCs). The tubular localization of OAT2 in human, monkey, and rat kidney was characterized. The overexpression of OAT2 significantly enhanced the uptake of creatinine in OAT2-HEK cells. Under physiologic conditions (creatinine concentrations of 41.2 and 123.5 µM), the initial rate of OAT2-mediated creatinine transport was approximately 11-, 80-, and 80-fold higher than OCT2, multidrug and toxin extrusion protein (MATE)1, and MATE2K, respectively, resulting in approximately 37-, 1850-, and 80-fold increase of the intrinsic transport clearance when normalized to the transporter protein concentrations. Creatinine intracellular uptake and transcellular transport in HRPTCs were decreased in the presence of 50 µM bromosulfophthalein and 100 µM indomethacin, which inhibited OAT2 more potently than other known creatinine transporters, OCT2 and multidrug and toxin extrusion proteins MATE1 and MATE2K (IC50: 1.3 µM vs. > 100 µM and 2.1 µM vs. > 200 µM for bromosulfophthalein and indomethacin, respectively) Immunohistochemistry analysis showed that OAT2 protein was localized to both basolateral and apical membranes of human and cynomolgus monkey renal proximal tubules, but appeared only on the apical membrane of rat proximal tubules. Collectively, the findings revealed the important role of OAT2 in renal secretion and possible reabsorption of creatinine and suggested a molecular basis for potential species difference in the transporter handling of creatinine. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  12. Effects of two desensitizing dentifrices on dentinal tubule occlusion with citric acid challenge: Confocal laser scanning microscopy study

    Directory of Open Access Journals (Sweden)

    Sneha Anil Rajguru

    2017-01-01

    Full Text Available Background: Dentin hypersensitivity results when patent tubules are exposed to pain-inducing external stimuli. Aim: This study aims to compare the effects of two desensitizing dentifrices containing NovaMin and arginine on dentinal tubule occlusion with and without citric acid challenge in vitro using confocal laser scanning microscopy (CLSM. Materials and Methods: Forty dentin discs were randomly divided into Groups I and II containing twenty specimens each, treated with NovaMin and arginine-containing dentifrices, respectively. Groups I and II were divided into subgroups A and B where IA and IIA underwent CLSM analysis to determine the percentage of tubule occlusion while IB and IIB underwent 0.3% citric acid challenge and CLSM analysis. A novel grading system was devised to categorize tubule occlusion. Results: In Group II, the percentage of occluded tubules was highest for IIA (72.25% ± 10.57% and least for IIB (42.55% ± 8.65% having statistical significance (P < 0.0005. In Group I, the difference between IA (49.9% ± 12.96% and IB (43.15% ± 12.43% was statistically insignificant (P = 0.249. On the comparison between IB and IIB statistically indifferent result was obtained (P = 0.901, whereas the difference between IA and IIA was statistically significant (P < 0.001. The results of grading system were for IA 50% of samples belonged to Grade 2, for IIA 60% - Grade 3, and for IB 70% and for IIB 90% - Grade 2. Conclusion: Dentinal tubule occlusion with arginine-containing dentifrice was significantly higher than NovaMin. However, it could not resist citric acid challenge as effectively as NovaMin. The effects of NovaMin were more sustainable as compared to arginine-containing dentifrice, thus proving to be a better desensitizing agent.

  13. Selective Insulin Resistance in the Kidney

    Science.gov (United States)

    Horita, Shoko; Nakamura, Motonobu; Suzuki, Masashi; Satoh, Nobuhiko; Suzuki, Atsushi; Seki, George

    2016-01-01

    Insulin resistance has been characterized as attenuation of insulin sensitivity at target organs and tissues, such as muscle and fat tissues and the liver. The insulin signaling cascade is divided into major pathways such as the PI3K/Akt pathway and the MAPK/MEK pathway. In insulin resistance, however, these pathways are not equally impaired. For example, in the liver, inhibition of gluconeogenesis by the insulin receptor substrate (IRS) 2 pathway is impaired, while lipogenesis by the IRS1 pathway is preserved, thus causing hyperglycemia and hyperlipidemia. It has been recently suggested that selective impairment of insulin signaling cascades in insulin resistance also occurs in the kidney. In the renal proximal tubule, insulin signaling via IRS1 is inhibited, while insulin signaling via IRS2 is preserved. Insulin signaling via IRS2 continues to stimulate sodium reabsorption in the proximal tubule and causes sodium retention, edema, and hypertension. IRS1 signaling deficiency in the proximal tubule may impair IRS1-mediated inhibition of gluconeogenesis, which could induce hyperglycemia by preserving glucose production. In the glomerulus, the impairment of IRS1 signaling deteriorates the structure and function of podocyte and endothelial cells, possibly causing diabetic nephropathy. This paper mainly describes selective insulin resistance in the kidney, focusing on the proximal tubule. PMID:27247938

  14. Allosteric effects in bacteriophage HK97 procapsids revealed directly from covariance analysis of cryo EM data.

    Science.gov (United States)

    Xu, Nan; Veesler, David; Doerschuk, Peter C; Johnson, John E

    2018-05-01

    The information content of cryo EM data sets exceeds that of the electron scattering potential (cryo EM) density initially derived for structure determination. Previously we demonstrated the power of data variance analysis for characterizing regions of cryo EM density that displayed functionally important variance anomalies associated with maturation cleavage events in Nudaurelia Omega Capensis Virus and the presence or absence of a maturation protease in bacteriophage HK97 procapsids. Here we extend the analysis in two ways. First, instead of imposing icosahedral symmetry on every particle in the data set during the variance analysis, we only assume that the data set as a whole has icosahedral symmetry. This change removes artifacts of high variance along icosahedral symmetry axes, but retains all of the features previously reported in the HK97 data set. Second we present a covariance analysis that reveals correlations in structural dynamics (variance) between the interior of the HK97 procapsid with the protease and regions of the exterior (not seen in the absence of the protease). The latter analysis corresponds well with hydrogen deuterium exchange studies previously published that reveal the same correlation. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Isolation and characterization of a primary proximal tubular epithelial cell model from human kidney by CD10/CD13 double labeling.

    Directory of Open Access Journals (Sweden)

    Cynthia Van der Hauwaert

    Full Text Available Renal proximal tubular epithelial cells play a central role in renal physiology and are among the cell types most sensitive to ischemia and xenobiotic nephrotoxicity. In order to investigate the molecular and cellular mechanisms underlying the pathophysiology of kidney injuries, a stable and well-characterized primary culture model of proximal tubular cells is required. An existing model of proximal tubular cells is hampered by the cellular heterogeneity of kidney; a method based on cell sorting for specific markers must therefore be developed. In this study, we present a primary culture model based on the mechanical and enzymatic dissociation of healthy tissue obtained from nephrectomy specimens. Renal epithelial cells were sorted using co-labeling for CD10 and CD13, two renal proximal tubular epithelial markers, by flow cytometry. Their purity, phenotypic stability and functional properties were evaluated over several passages. Our results demonstrate that CD10/CD13 double-positive cells constitute a pure, functional and stable proximal tubular epithelial cell population that displays proximal tubule markers and epithelial characteristics over the long term, whereas cells positive for either CD10 or CD13 alone appear to be heterogeneous. In conclusion, this study describes a method for establishing a robust renal proximal tubular epithelial cell model suitable for further experimentation.

  16. A Molecular Mechanism to Regulate Lysosome Motility for Lysosome Positioning and Tubulation

    Science.gov (United States)

    Li, Xinran; Rydzewski, Nicholas; Hider, Ahmad; Zhang, Xiaoli; Yang, Junsheng; Wang, Wuyang; Gao, Qiong; Cheng, Xiping; Xu, Haoxing

    2016-01-01

    To mediate the degradation of bio-macromolecules, lysosomes must traffic towards cargo-carrying vesicles for subsequent membrane fusion or fission. Mutations of the lysosomal Ca2+ channel TRPML1 cause lysosome storage disease (LSD) characterized by disordered lysosomal membrane trafficking in cells. Here we show that TRPML1 activity is required to promote Ca2+-dependent centripetal movement of lysosomes towards the perinuclear region, where autophagosomes accumulate, upon autophagy induction. ALG-2, an EF-hand-containing protein, serves as a lysosomal Ca2+ sensor that associates physically with the minus-end directed dynactin-dynein motor, while PI(3,5)P2, a lysosome-localized phosphoinositide, acts upstream of TRPML1. Furthermore, the PI(3,5)P2-TRPML1-ALG-2-dynein signaling is necessary for lysosome tubulation and reformation. In contrast, the TRPML1 pathway is not required for the perinuclear accumulation of lysosomes observed in many LSDs, which is instead likely caused by secondary cholesterol accumulation that constitutively activates Rab7-RILP-dependent retrograde transport. Collectively, Ca2+ release from lysosomes provides an on-demand mechanism regulating lysosome motility, positioning, and tubulation. PMID:26950892

  17. Deep-apical tubules: dynamic lipid-raft microdomains in the brush-border region of enterocytes

    DEFF Research Database (Denmark)

    Hansen, Gert H; Pedersen, Jens; Niels-Christiansen, Lise-Lotte

    2003-01-01

    microdomains. Deep-apical tubules were positioned close to the actin rootlets of adjacent microvilli in the terminal web region, which had a diameter of 50-100 nm, and penetrated up to 1 microm into the cytoplasm. Markers for transcytosis, IgA and the polymeric immunoglobulin receptor, as well as the resident...... lipid raft-containing compartments, but little is otherwise known about these raft microdomains. We therefore studied in closer detail apical lipid-raft compartments in enterocytes by immunogold electron microscopy and biochemical analyses. Novel membrane structures, deep-apical tubules, were visualized...... brush-border enzyme aminopeptidase N, were present in these deep-apical tubules. We propose that deep-apical tubules are a specialized lipid-raft microdomain in the brush-border region functioning as a hub in membrane trafficking at the brush border. In addition, the sensitivity to cholesterol depletion...

  18. SGLT2 inhibition in the diabetic kidney – an update

    Science.gov (United States)

    Novikov, Aleksandra; Vallon, Volker

    2016-01-01

    Purpose of review The sodium glucose cotransporter SGLT2 reabsorbs most of the glucose filtered by the kidneys. SGLT2 inhibitors reduce glucose reabsorption thereby lowering blood glucose levels and have been approved as new anti-hyperglycemic drugs. While the therapeutic strategy is very promising, many questions remain. Recent findings Using validated antibodies SGLT2 expression was localized to the brush border of the early proximal tubule in human kidney and was found upregulated in genetic murine models of type 1 and 2 diabetes. SGLT2 may functionally interact with the Na/H exchanger NHE3 in the proximal tubule. SGLT1-mediated reabsorption explains the fractional glucose reabsorption of 40–50% during SGLT2 inhibition. SGLT2 is expressed on pancreatic alpha cells where its inhibition induces glucagon secretion. SGLT2 inhibition lowers GFR in hyperfiltering diabetic patients consistent with the tubular hypothesis of diabetic hyperfiltration. New data indicate a potential of SGLT2 inhibition for renal medullary hypoxia and ketoacidosis, but also for blood glucose effect-dependent and independent nephroprotective actions, renal gluconeogenesis inhibition, reduction in cardiovascular mortality, and cancer therapy. Summary The findings expand and refine our understanding of SGLT2 and its inhibition, have relevance for clinical practice, and will help interpret ongoing clinical trials on the long-term safety and cardiovascular effects of SGLT2 inhibitors. PMID:26575393

  19. Setu hähküslaulud : viisitüübi kirjeldamise katse / Liisi Laanemets

    Index Scriptorium Estoniae

    Laanemets, Liisi

    2005-01-01

    Artikli aluseks on Eesti Muusikaakadeemia muusikateaduse osakonna 2003. a. kevade proseminaritöö, mille eesmärgiks oli leida setu pulmakombestikku kuuluva hähküslaulu viisi eri variantide põhjal sellele viisitüübile ainuomane mudel

  20. Family-Based Association Study Between SLC2A1, HK1, and LEPR Polymorphisms With Myelomeningocele in Chile

    Science.gov (United States)

    Suazo, José; Castillo, Silvia; Martin, Luz Maria; Rojas, Francisca; Santos, José Luis; Rotter, Karin; Solar, Margarita; Tapia, Eva

    2013-01-01

    Obese/diabetic mothers present a higher risk to develop offspring with myelomeningocele (MM), evidence supporting the role of energy homeostasis-related genes in neural tube defects. Using polymerase chain reaction–restriction fragment length polymorphism, we have genotyped SLC2A1, HK1, and LEPR single-nucleotide polymorphisms in 105 Chilean patients with MM and their parents in order to evaluate allele–phenotype associations by means of allele/haplotype transmission test (TDT) and parent-of-origin effects. We detected an undertransmission for the SLC2A1 haplotype T-A (rs710218-rs2229682; P = .040), which was not significant when only lower MM (90% of the cases) was analyzed. In addition, the leptin receptor rs1137100 G allele showed a significant increase in the risk of MM for maternal-derived alleles in the whole sample (2.43-fold; P = .038) and in lower MM (3.20-fold; P = .014). Our results support the role of genes involved in energy homeostasis in the risk of developing MM, thus sustaining the hypothesis of diverse pathways and genetic mechanisms acting in the expression of such birth defect. PMID:23427181

  1. Downregulation of the long noncoding RNA TUG1 inhibits the proliferation, migration, invasion and promotes apoptosis of renal cell carcinoma.

    Science.gov (United States)

    Zhang, Meng; Lu, Wei; Huang, Yiqiang; Shi, Jizhou; Wu, Xun; Zhang, Xiaolong; Jiang, Runze; Cai, Zhiming; Wu, Song

    2016-08-01

    Long non-coding RNAs, a newly discovered category of noncoding genes, play a leading role in various biological processes, including tumorigenesis. In our study, we aimed to examine the TUG1 expression, and explore the influence of TUG1 silencing on cell proliferation and apoptosis in renal cell carcinoma (RCC) cell lines. The TUG1 expression level was detected using quantitative real-time PCR reverse transcription-polymerase chain reaction in 40 paired clear cell renal cell carcinoma (ccRCC) and adjacent paired normal tissues, as well as four RCC cell lines and one normal human proximal tubule epithelial cell line HK-2. Small interfering RNA was applied to suppress the TUG1 expression in RCC cell lines (A489 and A704). In vitro assays were conducted to further deliberate its potential functions in RCC progression. The relative TUG1 expression was significantly higher in ccRCC tissues compared to the adjacent normal renal tissues. In addition, higher TUG1 expression was equally detected in RCC cell lines (particularly in A498 and A704) compared to HK-2. The ccRCC specimens with higher TUG1 expression had a higher Fuhrman grade and larger tumor size than those with lower TUG1 expression. In vitro assays results suggested that knockdown of TUG1 suppressed RCC cells migration, invasion and proliferation, while the apoptosis process was activated. Our results indicate that TUG1 is identified as a novel oncogene in the morbid state of RCC, which potentially acts as a therapeutic target/biomarker in RCC. The graphic abstract of the present work.

  2. Photoelectrochemical reactivity of polyoxophosphotungstates embedded in titania tubules

    International Nuclear Information System (INIS)

    Xie Yibing

    2006-01-01

    A highly ordered and crystallized titania (TiO 2 ) nanotube array is fabricated by a low-voltage anodization plus a post-embedding calcination process. Polyoxophosphotungstate-titania (POPTA-TiO 2 ) composite catalyst is synthesized by embedding POPTA in TiO 2 tubule channels to improve the photoelectrochemical properties. The morphological characteristics and crystal behaviour of POPTA-TiO 2 are examined by field-emission scanning electron microscopy and x-ray diffraction. The stability of the chemical structure has been analysed by Fourier transformed infrared spectroscopy measurements. The photoelectrochemical properties are investigated by means of the polarization current response. Photocatalytic and photoelectrocatalytic reactivities for the degradation of an endocrine disrupting chemical have also been investigated to examine the photoelectrochemical reaction efficiency of POPTA-TiO 2 composite catalyst

  3. Tietohallintolaki ja sen vaikutukset sähköisen asioinnin kokonaisarkkitehtuuriin

    OpenAIRE

    Lindblad-Ahonen, Anne

    2013-01-01

    Tutkielman tavoitteena on tutkia miten uusi tietohallintolaki sekä sen asettamat vaatimukset vaikuttavat julkishallinnon (yhteisten) tietoteknisten ratkaisujen kehittämiseen ja toteuttamiseen. Vaikutusta pyritään selvittämään tutkimalla miten eri kaupungit ovat kuvanneet toimintojaan kokonaisarkkitehtuurin näkökulmasta, varsinkin varhaiskasvatuksen sähköisen asioinnin osalta. Tietohallintolaki edellyttää, että julkisen hallinnon viranomaisen on tietojärjestelmien yhteentoimivuuden mahdoll...

  4. SPATIALLY RESOLVING THE HK Tau B EDGE-ON DISK FROM 1.2 TO 4.7 μm: A UNIQUE SCATTERED LIGHT DISK

    International Nuclear Information System (INIS)

    McCabe, C.; Duchene, G.; Pinte, C.; Menard, F.; Stapelfeldt, K. R.; Ghez, A. M.

    2011-01-01

    We present spatially resolved scattered light images of the circumstellar disk around HK Tau B at 3.8 and 4.7 μm taken with the Keck Telescope Laser Guide Star Adaptive Optics (AO) system, and 1.6-2.12 μm images taken with the Very Large Telescope/NACO AO system. Combined with previously published optical Hubble Space Telescope data, we investigate the spatially resolved scattered light properties of this edge-on circumstellar disk and probe for the presence of large grains. The 0.6-3.8 μm scattered light observations reveal strong, and in some cases, unusual, wavelength dependencies in the observed disk morphology. The separation between the two scattered light nebulae, which is directly proportional to the disk-mass-opacity product, decreases by 30% between 0.6 and 3.8 μm. Over the same wavelength range, the FWHM of the disk nebulosity declines by a factor of two, while the flux ratio between the two nebulae increases by a factor of ∼8. No other disk known to date shows a flux ratio that increases with wavelength. Both the FWHM and nebula flux ratio are affected by the scattering phase function and the observed behavior can most readily be explained by a phase function that becomes more forward throwing with wavelength. The multi-wavelength scattered light observations also confirm the asymmetric nature of the disk and show that the level of asymmetry is a function of wavelength. We use the MCFOST radiative transfer code to model the disk at four wavelengths, corresponding to the I, H, Ks, and L' bandpasses. A single power-law grain size distribution can recreate the observed disk properties simultaneously at all four wavelengths. Bayesian analysis of the dust parameters finds a 99% probability that the maximum grain size is 5.5 μm or larger. We also find that the grain size distribution is steep, with a 99% probability of a power-law index of 4.2 or larger, suggesting that these large grains are a small fraction of the overall dust population. The best

  5. Visualizing the origins of selfish de novo mutations in individual seminiferous tubules of human testes.

    Science.gov (United States)

    Maher, Geoffrey J; McGowan, Simon J; Giannoulatou, Eleni; Verrill, Clare; Goriely, Anne; Wilkie, Andrew O M

    2016-03-01

    De novo point mutations arise predominantly in the male germline and increase in frequency with age, but it has not previously been possible to locate specific, identifiable mutations directly within the seminiferous tubules of human testes. Using microdissection of tubules exhibiting altered expression of the spermatogonial markers MAGEA4, FGFR3, and phospho-AKT, whole genome amplification, and DNA sequencing, we establish an in situ strategy for discovery and analysis of pathogenic de novo mutations. In 14 testes from men aged 39-90 y, we identified 11 distinct gain-of-function mutations in five genes (fibroblast growth factor receptors FGFR2 and FGFR3, tyrosine phosphatase PTPN11, and RAS oncogene homologs HRAS and KRAS) from 16 of 22 tubules analyzed; all mutations have known associations with severe diseases, ranging from congenital or perinatal lethal disorders to somatically acquired cancers. These results support proposed selfish selection of spermatogonial mutations affecting growth factor receptor-RAS signaling, highlight its prevalence in older men, and enable direct visualization of the microscopic anatomy of elongated mutant clones.

  6. Tubulation of class II MHC compartments is microtubule dependent and involves multiple endolysosomal membrane proteins in primary dendritic cells.

    Science.gov (United States)

    Vyas, Jatin M; Kim, You-Me; Artavanis-Tsakonas, Katerina; Love, J Christopher; Van der Veen, Annemarthe G; Ploegh, Hidde L

    2007-06-01

    Immature dendritic cells (DCs) capture exogenous Ags in the periphery for eventual processing in endolysosomes. Upon maturation by TLR agonists, DCs deliver peptide-loaded class II MHC molecules from these compartments to the cell surface via long tubular structures (endolysosomal tubules). The nature and rules that govern the movement of these DC compartments are unknown. In this study, we demonstrate that the tubules contain multiple proteins including the class II MHC molecules and LAMP1, a lysosomal resident protein, as well as CD63 and CD82, members of the tetraspanin family. Endolysosomal tubules can be stained with acidotropic dyes, indicating that they are extensions of lysosomes. However, the proper trafficking of class II MHC molecules themselves is not necessary for endolysosomal tubule formation. DCs lacking MyD88 can also form endolysosomal tubules, demonstrating that MyD88-dependent TLR activation is not necessary for the formation of this compartment. Endolysosomal tubules in DCs exhibit dynamic and saltatory movement, including bidirectional travel. Measured velocities are consistent with motor-based movement along microtubules. Indeed, nocodazole causes the collapse of endolysosomal tubules. In addition to its association with microtubules, endolysosomal tubules follow the plus ends of microtubules as visualized in primary DCs expressing end binding protein 1 (EB1)-enhanced GFP.

  7. Piecewise-Constant-Model-Based Interior Tomography Applied to Dentin Tubules

    Directory of Open Access Journals (Sweden)

    Peng He

    2013-01-01

    Full Text Available Dentin is a hierarchically structured biomineralized composite material, and dentin’s tubules are difficult to study in situ. Nano-CT provides the requisite resolution, but the field of view typically contains only a few tubules. Using a plate-like specimen allows reconstruction of a volume containing specific tubules from a number of truncated projections typically collected over an angular range of about 140°, which is practically accessible. Classical computed tomography (CT theory cannot exactly reconstruct an object only from truncated projections, needless to say a limited angular range. Recently, interior tomography was developed to reconstruct a region-of-interest (ROI from truncated data in a theoretically exact fashion via the total variation (TV minimization under the condition that the ROI is piecewise constant. In this paper, we employ a TV minimization interior tomography algorithm to reconstruct interior microstructures in dentin from truncated projections over a limited angular range. Compared to the filtered backprojection (FBP reconstruction, our reconstruction method reduces noise and suppresses artifacts. Volume rendering confirms the merits of our method in terms of preserving the interior microstructure of the dentin specimen.

  8. Masonry structures built with fictile tubules: Experimental and numerical analyses

    Science.gov (United States)

    Tiberti, Simone; Scuro, Carmelo; Codispoti, Rosamaria; Olivito, Renato S.; Milani, Gabriele

    2017-11-01

    Masonry structures with fictile tubules were a distinctive building technique of the Mediterranean area. This technique dates back to Roman and early Christian times, used to build vaulted constructions and domes with various geometrical forms by virtue of their modular structure. In the present work, experimental tests were carried out to identify the mechanical properties of hollow clay fictile tubules and a possible reinforcing technique for existing buildings employing such elements. The experimental results were then validated by devising and analyzing numerical models with the FE software Abaqus, also aimed at investigating the structural behavior of an arch via linear and nonlinear static analyses.

  9. Effect of dental materials on gluconeogenesis in rat kidney tubules

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, F.X.; Durner, J.; Mueckter, H.; Elsenhans, B.; Forth, W. [Muenchen Univ. (Germany). Walter-Straub-Institut fuer Pharmakologie und Toxikologie; Kunzelmann, K.H.; Hickel, R. [Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich (Germany); Spahl, W. [Institute of Organic Chemistry, Ludwig-Maximilians-University of Munich (Germany); Hume, W.R. [Dental Research Institute, Univ. of California, Los Angeles, CA (United States); Moes, G.W. [TNO Prins-Maurits-Laboratorium, Rijswijk (Netherlands)

    1999-09-01

    The effect of dental composite components triethyleneglycoldimethacrylate (TEGDMA) and hydroxyethylmethacrylate (HEMA) as well as mercuric chloride (HgCl{sub 2}) and methylmercury chloride (MeHgCl) on gluconeogenesis was investigated in isolated rat kidney tubules. From starved rats kidney tubules were prepared and isolated by digestion with collagenase. Every 10 min up to 60 min 1-ml samples were drawn from the cell suspension for quantitating the glucose content. Glucose formation in controls was 3.3 {+-} 0.2 nmol/mg . per min (mean {+-} SEM, n=21). Relative rates of glucose formation were obtained by expressing individual rates as a percentage of the corresponding control. X-Y concentration curves (effective concentration, EC) of the substances were calculated by fitting a four-parametric sigmoid function to the relative rates of glucose formation at various test concentrations. At the end of the incubation period cell viability was assessed by trypan blue exclusion. Cell viability decreased within the 60 min interval from 90 to approx. 80% (controls), <25 (HEMA), <20 (TEGDMA), <10 (MeHgCl), and <10% (HgCl{sub 2}). Values of 50% effective concentration (EC{sub 50}) were calculated from fitted curves. EC{sub 50} values were (mmol; mean {+-} SEM; n=4): HEMA, 17.7 {+-} 2.9; TEGDMA, 1.8 {+-} 0.2; MeHgCl, 0.018 {+-} 0.0005; and HgCl{sub 2}, 0.0016 {+-} 0.0005. The toxic effect of HgCl{sub 2} was {proportional{underscore}to}1000 or 10 000 higher than that of the dental composite components TEGDMA or HEMA, respectively. (orig.)

  10. Revealing t-tubules in striated muscle with new optical super-resolution microscopy techniques

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    Isuru D. Jayasinghe

    2014-12-01

    Full Text Available The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM, has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies.

  11. A validation study of the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) in Chinese older adults in Hong Kong.

    Science.gov (United States)

    Yeung, P Y; Wong, L L; Chan, C C; Leung, Jess L M; Yung, C Y

    2014-12-01

    To validate the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) in identification of mild cognitive impairment and dementia in Chinese older adults. Cross-sectional study. Cognition clinic and memory clinic of a public hospital in Hong Kong. A total of 272 participants (dementia, n=130; mild cognitive impairment, n=93; normal controls, n=49) aged 60 years or above were assessed using HK-MoCA. The HK-MoCA scores were validated against expert diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for dementia and Petersen's criteria for mild cognitive impairment. Statistical analysis was performed using receiver operating characteristic curve and regression analyses. Additionally, comparison was made with the Cantonese version of Mini-Mental State Examination and Global Deterioration Scale. The optimal cutoff score for the HK-MoCA to differentiate cognitive impaired persons (mild cognitive impairment and dementia) from normal controls was 21/22 after adjustment of education level, giving a sensitivity of 0.928, specificity of 0.735, and area under the curve of 0.920. Moreover, the cutoff to detect mild cognitive impairment was 21/22 with a sensitivity of 0.828, specificity of 0.735, and area under the curve of 0.847. Score of the Cantonese version of the Mini-Mental State Examination to detect mild cognitive impairment was 26/27 with a sensitivity of 0.785, specificity of 0.816, and area under the curve of 0.857. At the optimal cutoff of 18/19, HK-MoCA identified dementia from controls with a sensitivity of 0.923, specificity of 0.918, and area under the curve of 0.971. The HK-MoCA is a useful cognitive screening instrument for use in Chinese older adults in Hong Kong. A score of less than 22 should prompt further diagnostic assessment. It has comparable sensitivity with the Cantonese version of Mini-Mental State Examination for detection of mild cognitive impairment. It is brief and feasible to conduct in the

  12. Bioreporter pseudomonas fluorescens HK44 immobilized in a silica matrix

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    Trogl J.

    2003-01-01

    Full Text Available The bioluminescent bioreporter Pseudomonas fluorescens HK44, the whole cell bacterial biosensor that responds to naphthalene and its metabolites via the production of visible light, was immobilized into a silica matrix by the sol-gel technique. The bioluminescence intensities were measured in the maximum of the bioluminescence band at X = 500 nm. The immobilized cells (>105 cells per g silica matrix produced light after induction by salicylate (cone. > 10 g/l, naphthalene and aminobenzoic acid. The bioluminescence intensities induced by 2,3-dihydroxynaphthalene 3-hydroxybenzoic acid and 4-hydroxybenzoic acid were comparable to a negative control. The cells in the silica layers on glass slides produced light in response to the presence of an inductor at least 8 months after immobilization, and >50 induction cycles. The results showed that these test slides could be used as assays for the multiple determination of water pollution.

  13. Probing SGLT2 as a therapeutic target for diabetes: Basic physiology and consequences

    Science.gov (United States)

    Gallo, Linda A; Wright, Ernest M; Vallon, Volker

    2018-01-01

    Traditional treatments for type 1 and type 2 diabetes are often associated with side effects, including weight gain and hypoglycaemia that may offset the benefits of blood glucose lowering. The kidneys filter and reabsorb large amounts of glucose, and urine is almost free of glucose in normoglycaemia. The sodium-dependent glucose transporter (SGLT)-2 in the early proximal tubule reabsorbs the majority of filtered glucose. Remaining glucose is reabsorbed by SGLT1 in the late proximal tubule. Diabetes enhances renal glucose reabsorption by increasing the tubular glucose load and the expression of SGLT2 (as shown in mice), which maintains hyperglycaemia. Inhibitors of SGLT2 enhance urinary glucose excretion and thereby lower blood glucose levels in type 1 and type 2 diabetes. The load-dependent increase in SGLT1-mediated glucose reabsorption explains why SGLT2 inhibitors in normoglycaemic conditions only excrete ~50% of the filtered glucose. The role of SGLT1 in both renal and intestinal glucose reabsorption provides a rationale for the development of dual SGLT1/2 inhibitors. SGLT2 inhibitors lower blood glucose levels independent of insulin and induce pleiotropic actions that may be relevant in the context of lowering cardiovascular risk. Ongoing long-term clinical studies will determine whether SGLT2 inhibitors have a safety profile and exert cardiovascular benefits that are superior to traditional agents. PMID:25616707

  14. VizieR Online Data Catalog: HK photometry in an UCHII region near Sh2-217 (Brand+, 2011)

    Science.gov (United States)

    Brand, J.; Massi, F.; Zavagno, A.; Deharveng, L.; Lefloch, B.

    2010-11-01

    Coordinates and photometric parameters (magnitudes and colours) are presented of the stars located in a molecular condensation on the SW-border of the Galactic HII region Sh2-217. The data were obtained on January 4, 2004 with the 3.58-m Telescopio Nazionale Galileo (TNG; La Palma, Canary Islands, Spain). Near-infrared observations were carried out through H and K' broad-band filters with the camera NICS. The image scale is 0.25arcsec/pixel, yielding a field of view of about 4.2'x4.2'. Observing strategy and exposure times are described in Deharveng et al. (2006A&A...458..191D), the only difference being that the dithering sequence for the H-band images was the same as adopted for K'. The data reduction steps adopted are outlined in Deharveng et al. (2006A&A...458..191D). Aperture photometry was done using the DAOPHOT package in IRAF. We followed the same procedure described in Deharveng et al. (2006A&A...458..191D) to obtain aperture photometry, after which PSF-fitting photometry was performed. Although the seeing was good (<1"), the night was barely photometric, so we calibrated our H, K' photometry with that performed on the same field by Deharveng et al. (2003, Cat. J/A+A/399/1135). We calculated the difference in magnitudes for each coinciding source and plotted it against our derived instrumental H-K'. A colour term was present in K' because of the difference between the K and K' filters. After a best-fit calibration, a residual r.m.s. of about 0.2mag. was present in the difference between our photometry and that of Deharveng et al. (2003, J/A+A/399/1135), probably because of the different seeing and possibly also due to the intrinsic variability of young stars. Our photometry is thus on the same HK standard system as Deharveng et al. (2003, J/A+A/399/1135). Sources with K, H < 11-12 are in the non-linear regime or saturated, but such bright objects are few in number and lie outside the cluster, and are probably foreground stars. The approximate limiting

  15. Tubulation of Class II MHC Compartments Is Microtubule Dependent and Involves Multiple Endolysosomal Membrane Proteins in Primary Dendritic Cells1

    Science.gov (United States)

    Vyas, Jatin M.; Kim, You-Me; Artavanis-Tsakonas, Katerina; Love, J. Christopher; Van der Veen, Annemarthe G.; Ploegh, Hidde L.

    2009-01-01

    Immature dendritic cells (DCs) capture exogenous Ags in the periphery for eventual processing in endolysosomes. Upon maturation by TLR agonists, DCs deliver peptide-loaded class II MHC molecules from these compartments to the cell surface via long tubular structures (endolysosomal tubules). The nature and rules that govern the movement of these DC compartments are unknown. In this study, we demonstrate that the tubules contain multiple proteins including the class II MHC molecules and LAMP1, a lysosomal resident protein, as well as CD63 and CD82, members of the tetraspanin family. Endolysosomal tubules can be stained with acidotropic dyes, indicating that they are extensions of lysosomes. However, the proper trafficking of class II MHC molecules themselves is not necessary for endolysosomal tubule formation. DCs lacking MyD88 can also form endolysosomal tubules, demonstrating that MyD88-dependent TLR activation is not necessary for the formation of this compartment. Endolysosomal tubules in DCs exhibit dynamic and saltatory movement, including bidirectional travel. Measured velocities are consistent with motor-based movement along microtubules. Indeed, nocodazole causes the collapse of endolysosomal tubules. In addition to its association with microtubules, endolysosomal tubules follow the plus ends of microtubules as visualized in primary DCs expressing end binding protein 1 (EB1)-enhanced GFP. PMID:17513769

  16. The Lowe syndrome protein OCRL1 is required for endocytosis in the zebrafish pronephric tubule.

    Directory of Open Access Journals (Sweden)

    Francesca Oltrabella

    2015-04-01

    Full Text Available Lowe syndrome and Dent-2 disease are caused by mutation of the inositol 5-phosphatase OCRL1. Despite our increased understanding of the cellular functions of OCRL1, the underlying basis for the renal tubulopathy seen in both human disorders, of which a hallmark is low molecular weight proteinuria, is currently unknown. Here, we show that deficiency in OCRL1 causes a defect in endocytosis in the zebrafish pronephric tubule, a model for the mammalian renal tubule. This coincides with a reduction in levels of the scavenger receptor megalin and its accumulation in endocytic compartments, consistent with reduced recycling within the endocytic pathway. We also observe reduced numbers of early endocytic compartments and enlarged vacuolar endosomes in the sub-apical region of pronephric cells. Cell polarity within the pronephric tubule is unaffected in mutant embryos. The OCRL1-deficient embryos exhibit a mild ciliogenesis defect, but this cannot account for the observed impairment of endocytosis. Catalytic activity of OCRL1 is required for renal tubular endocytosis and the endocytic defect can be rescued by suppression of PIP5K. These results indicate for the first time that OCRL1 is required for endocytic trafficking in vivo, and strongly support the hypothesis that endocytic defects are responsible for the renal tubulopathy in Lowe syndrome and Dent-2 disease. Moreover, our results reveal PIP5K as a potential therapeutic target for Lowe syndrome and Dent-2 disease.

  17. Teaching Glycoproteins with a Classical Paper: Knowledge and Methods in the Course of an Exciting Discovery--The story of Discovering HK-ATPase [Beta]-Subunit

    Science.gov (United States)

    Zhu, Lixin

    2008-01-01

    To integrate research into the teaching of glycoproteins, the story of discovering hydrogen-potassium ATPase (HK-ATPase) [beta] subunit is presented in a way covering all the important teaching points. The interaction between the HK-ATPase [alpha] subunit and a glycoprotein of 60-80 kDa was demonstrated to support the existence of the [beta]…

  18. Role of carbonate in the cytotoxicity of carboplatin.

    Science.gov (United States)

    Di Pasqua, Anthony J; Goodisman, Jerry; Kerwood, Deborah J; Toms, Bonnie B; Dubowy, Ronald L; Dabrowiak, James C

    2007-06-01

    Carboplatin, [Pt(NH3)2(CBDCA-O,O')], 1, where CBDCA is cyclobutane-1,1-dicarboxylate, is used against ovarian, lung, and other types of cancer. We recently showed (Di Pasqua et al. (2006) Chem. Res. Toxicol. 19, 139-149) that carboplatin reacts with carbonate under conditions that simulate therapy to produce carbonato carboplatin, cis-[Pt(NH3)2(O-CBDCA)(CO3)]2-, 2. We use 13C and 1H NMR and UV-visible absorption spectroscopy to show that solutions containing carboplatin that have been aged in carbonate buffer under various conditions contain 1, 2, and other compounds. We then show that aging carboplatin in carbonate produces compounds that are more toxic to human neuroblastoma (SK-N-SH), proximal renal tubule (HK-2) and Namalwa-luc Burkitt's lymphoma (BL) cells than carboplatin alone. Moreover, increasing the aging time increases the cytotoxicity of the platinum solutions as measured by the increase in cell death. Although HK-2 cells experience a large loss in survival upon exposure to carbonato forms of the drug, they have the highest values of IC50 of the three cell lines studied, so that HK-2 cells remain the most resistant to the toxic effects of the carbonato forms in the culture medium. This is consistent with the well-known low renal toxicity observed for carboplatin in therapy. The uptake rates for normal Jurkat cells (NJ) and cisplatin-resistant Jurkat cells (RJ), measured by inductively coupled plasma mass spectrometry (ICP-MS), are 16.6 +/- 4.2 and 12.3 +/- 4.8 amol of Pt h-1 cell-1, respectively, when exposed to carboplatin alone. However, when these cells are exposed to carboplatin that has been aged in carbonate media, normal Jurkat cells strongly bind/take up Pt at a rate of 14.5 +/- 4.1 amol of Pt h-1 cell-1, while resistant cells strongly bind/take up 5.1 +/- 3.3 amol of Pt h-1 cell-1. Collectively, these studies show that carboplatin carbonato species may play a major role in the cytotoxicity and uptake of carboplatin by cells.

  19. THE NEPHROTOXICITY RISK IN RATS SUBJECTED TO HEAVY MUSCLE ACTIVITY

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    Gülsen Öner

    2009-09-01

    Full Text Available When the body is exposed to insults, the kidneys exhibit adaptive changes termed renal cytoresistance, characterized by cholesterol accumulation in the membranes of the tubule cells. However, heavy muscle activity has not yet been accepted as one of the stressors that could lead to cytoresistance. In order to study the renal functional characteristics of animals exposed to heavy muscle activity, rats were subjected to exhaustive treadmill exercise for 5 days and their data was compared to those of sedentary controls. It was found that in exercised rats, blood lactate, muscle citrate synthase and proximal tubule peroxynitrite levels were all elevated, suggesting the presence of oxidative stress in the proximal tubule segments. However, mean arterial pressure, renal blood flow, glomerular filtration rate, fractional excretion of sodium and potassium, and organic anion excretion remained normal. Despite unchanged blood cholesterol levels, cholesterol loading in the proximal tubule segments, especially the free form, and decreased lactate dehydrogenase release from cytoresistant proximal tubule segments indicated the development of renal cytoresistance. However, this resistance did not seem to have protected the kidneys as expected because organic anion accumulation associated with glycosuria and proteinuria, in addition to the elevated urinary cholesterol levels, all imply the presence of an impaired glomerular permeability and reabsorption in the proximal tubule cells. Therefore, we suggest that in response to heavy muscle activity the tubular secretion may remain intact, although cytoresistance in the proximal tubule cells may affect the tubular reabsorptive functions and basolateral uptake of substances. Thus, this differential sensitivity in the cytoresistance should be taken into account during functional evaluation of the kidneys

  20. The Renal Sodium Bicarbonate Cotransporter NBCe2: Is It a Major Contributor to Sodium and pH Homeostasis?

    Science.gov (United States)

    Felder, Robin A; Jose, Pedro A; Xu, Peng; Gildea, John J

    2016-09-01

    The sodium bicarbonate cotransporter (NBCe2, aka NBC4) was originally isolated from the human testis and heart (Pushkin et al. IUBMB Life 50:13-19, 2000). Subsequently, NBCe2 was found in diverse locations where it plays a role in regulating sodium and bicarbonate transport, influencing intracellular, extracellular, interstitial, and ultimately plasma pH (Boron et al. J Exp Biol. 212:1697-1706, 2009; Parker and Boron, Physiol Rev. 93:803-959, 2013; Romero et al. Mol Asp Med. 34:159-182, 2013). NBCe2 is located in human and rodent renal-collecting duct and proximal tubule. While much is known about the two electrogenic sodium bicarbonate cotransporters, NBCe1 and NBCe2, in the regulation of sodium homeostasis and pH balance in the rodent kidney, little is known about their roles in human renal physiology. NBCe2 is located in the proximal tubule Golgi apparatus under basal conditions and then disperses throughout the cell, but particularly into the apical membrane microvilli, during various maneuvers that increase intracellular sodium. This review will summarize our current understanding of the distribution and function of NBCe2 in the human kidney and how genetic variants of its gene, SLC4A5, contribute to salt sensitivity of blood pressure.

  1. The H+/K+ ATPase Inhibitor SCH-28080 Inhibits Insulin Secretion and Induces Cell Death in INS-1E Rat Insulinoma Cells

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    Martin Jakab

    2017-10-01

    Full Text Available Background/Aims: Glucose-stimulated insulin secretion (GSIS of pancreatic β-cells involves glucose uptake and metabolism, closure of KATP channels and depolarization of the cell membrane potential (Vmem, activation of voltage-activated Ca2+ currents (ICav and influx of Ca2+, which eventually triggers hormone exocytosis. Beside this classical pathway, KATP-independent mechanisms such as changes in intracellular pH (pHi or cell volume, which also affect β-cell viability, can elicit or modify insulin release. In β-cells the regulation of pHi is mainly accomplished by Na+/H+ exchangers (NHEs. To investigate if other proton extrusion mechanisms than NHEs are involved in pH regulation, we tested for the presence of the non-gastric H+/K+ ATPase in rat insulinoma cells and assessed effects of the H+/K+ ATPase inhibitor SCH-28080 on insulin secretion, cell viability and apoptosis. Methods: In INS-1E cell cultures, H+/K+ ATPase gene and protein expression was analyzed by reverse transcription PCR and Western blotting. Intracellular pH (pHi recovery after acute acidic load was measured by NH4Cl prepulsing using BCECF. Insulin secretion was determined by ELISA from the cell culture supernatant. Vmem, K+ and Ca2+ currents were recorded using patch clamp. Overall cell responses were determined using resazurin (viability and cytotoxicity assays. The mean cell volume (MCV, cell granularity (side-scatter; SSC, phosphatidylserine (PS exposure, cell membrane integrity, caspase activity and the mitochondrial membrane potential (ΔΨm were measured by flow cytometry. Results: We found that the α-subunit of the non-gastric H+/K+ ATPase (HKα2 is expressed on mRNA and protein level. However, compared to rat colon tissue, in INS-1E cells mRNA abundance was very low. In NH4Cl prepulsing experiments no K+-dependent pHi recovery was observed under Na+-free extracellular conditions. Nonetheless within 1 h, 20 µM SCH-28080 inhibited GSIS by ∼50%, while basal release

  2. Comparative Evaluation of Efficacy of Iontophoresis with 0.33% Sodium Fluoride Gel and Diode Laser Alone on Occlusion of Dentinal Tubules.

    Science.gov (United States)

    Patil, Anup Raghunath; Varma, Siddhartha; Suragimath, Girish; Abbayya, Keshava; Zope, Sameer Anil; Kale, Vishwajeet

    2017-08-01

    Dentinal Hypersensitivity (DH) is one of the most commonly encountered clinical problems. Literature reveals no specific therapy to satisfactorily eliminate dentinal hypersensitivity. The aim of this study was to assess and compare the efficacy of iontophoresis with 0.33% Sodium Fluoride (NaF) gel and diode laser alone in dentinal tubule occlusion. This in vitro study included 20 teeth with intact root surfaces unaltered by extraction procedure for specimen preparation. Each tooth was cleaned, air dried and cut into three sections. Total 60 sections were prepared (30 longitudinal and 30 transverse sections), which were acid etched. In control group, no treatment was carried. In iontophoresis treatment group, samples were inserted into a foam tray containing 0.33 % NaF Gel and subjected to 1.5 mA output current for three minutes. In laser treatment group, specimens were lased with 980 nm diode laser at 0.5 W/PW (62.2J /cm 2 ) in a noncontact mode for 30 seconds. Specimens were evaluated under Scanning Electron Microscope (SEM) at 10KV to 20KV under x 2000, x5000 magnification for surface characteristics and patency of dentinal tubules. Total number of tubules visible, open, completely and partially occluded were recorded in each microphotograph and compared. On comparison, laser group showed the least number of open tubules i.e., 130 (31.1%) followed by iontophoresis group, 155 (51.32%) and control group 417 (100%). Diode laser application provided better results as compared to iontophoresis on occlusion of dentinal tubules. Hence, it can be used to treat the patients with DH.

  3. Factor Analysis of the HK-WISC at 11 Age Levels between 5 and 15 Years.

    Science.gov (United States)

    Chan, David W.

    1984-01-01

    Factor analyzed the Hong Kong Wechsler Intelligence Scale for Children (HK-WISC), across 11 age groups in the standardization sample of Chinese children (N=1,100). Results indicated that the three factors, Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility, identified in the Wechsler Intelligence Scale for…

  4. Residential Proximity to Major Roadways and Risk of Type 2 Diabetes Mellitus: A Meta-Analysis

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    Zhiqing Zhao

    2016-12-01

    Full Text Available Research indicates that higher levels of traffic-related pollution exposure increase the risk of diabetes, but the association between road proximity and diabetes risk remains unclear. To assess and quantify the association between residential proximity to major roadways and type 2 diabetes, a systematic review and meta-analysis was performed. Embase, Medline, and Web of Science were searched for eligible studies. Using a random-effects meta-analysis, the summary relative risks (RRs were calculated. Bayesian meta-analysis was also performed. Eight studies (6 cohort and 2 cross-sectional with 158,576 participants were finally included. The summary unadjusted RR for type 2 diabetes associated with residential proximity to major roadways was 1.24 (95% confidence interval [CI]: 1.07–1.44, p = 0.001, I2 = 48.1%. The summary adjusted RR of type 2 diabetes associated with residential proximity to major roadways was 1.12 (95% CI: 1.03–1.22, p = 0.01, I2 = 17.9%. After excluding two cross-sectional studies, the summary results suggested that residential proximity to major roadways could increase type 2 diabetes risk (Adjusted RR = 1.13; 95% CI: 1.02–1.27, p = 0.025, I2 = 36.6%. Bayesian meta-analysis showed that the unadjusted RR and adjusted RR of type 2 diabetes associated with residential proximity to major roadways were 1.22 (95% credibility interval: 1.06–1.55 and 1.13 (95% credibility interval: 1.01–1.31, respectively. The meta-analysis suggested that residential proximity to major roadways could significantly increase risk of type 2 diabetes, and it is an independent risk factor of type 2 diabetes. More well-designed studies are needed to further strengthen the evidence.

  5. Fluoride-associated ultrastructural changes and apoptosis in human renal tubule: a pilot study.

    Science.gov (United States)

    Quadri, J A; Sarwar, S; Sinha, A; Kalaivani, M; Dinda, A K; Bagga, A; Roy, T S; Das, T K; Shariff, A

    2018-01-01

    The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.

  6. Development and Validation of Chinese Health Literacy Scale for Low Salt Consumption-Hong Kong Population (CHLSalt-HK.

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    P H Chau

    Full Text Available Globally, sodium intake far exceeds the level recommended by the World Health Organization. Assessing health literacy related to salt consumption among older adults could guide the development of interventions that target their knowledge gaps, misconceptions, or poor dietary practices. This study aimed to develop and validate the Chinese Health Literacy Scale for Low Salt Consumption-Hong Kong population (CHLSalt-HK. Based on previous studies on salt intake and nutrition label reading in other countries, we developed similar questions that were appropriate for the Chinese population in Hong Kong. The questions covered the following eight broad areas: functional literacy (term recognition and nutrition label reading, knowledge of the salt content of foods, knowledge of the diseases related to high salt intake, knowledge of international standards, myths about salt intake, attitudes toward salt intake, salty food consumption practices, and nutrition label reading practices. Eight professionals, including doctors, nurses, and dietitians, provided feedback on the scale. The psychometric properties of the scale were assessed based on data collected from a convenience sample of 603 Chinese elderly adults recruited from Elderly Health Centres in Hong Kong. The 49-item CHLSalt-HK had a possible score range of 0 to 98, with a higher score indicating higher health literacy related to salt intake. The CHLSalt-HK had acceptable content validity; the item-level Content Validity Index ranged from 0.857 to 1.000, and the scale-level Content Validity Index was 0.994. Additionally, it had good internal consistency (Cronbach's alpha of 0.799 and good test-retest reliability (intraclass correlation coefficient of 0.846. The mean CHLSalt-HK score among those who were aware of the public education slogan about nutrition labels and sodium intake was higher by 3.928 points (95% confidence interval: 1.742 to 6.115 than that among those who were not aware of the slogan

  7. Localization of Mg2+-sensing shark kidney calcium receptor SKCaR in kidney of spiny dogfish, Squalus acanthias.

    Science.gov (United States)

    Hentschel, Hartmut; Nearing, Jacqueline; Harris, H William; Betka, Marlies; Baum, Michelle; Hebert, Steven C; Elger, Marlies

    2003-09-01

    We recently cloned a homologue of the bovine parathyroid calcium receptor from the kidney of a spiny dogfish (Squalus acanthias) and termed this new protein SKCaR. SKCaR senses alterations in extracellular Mg2+ after its expression in human embryonic kidney cells (Nearing J, Betka M, Quinn S, Hentschel H, Elger M, Baum M, Bai M, Chattopadyhay N, Brown E, Hebert S, and Harris HW. Proc Natl Acad. Sci USA 99: 9231-9236, 2002). In this report, we used light and electron microscopic immunocytochemical techniques to study the distribution of SKCaR in dogfish kidney. SKCaR antiserum bound to the apical membranes of shark kidney epithelial cells in the following tubular segments: proximal tubules (PIa and PIIb), late distal tubule, and collecting tubule/collecting duct as well as diffusely labeled cells of early distal tubule. The highly specific distribution of SKCaR in mesial tissue as well as lateral countercurrent bundles of dogfish kidney is compatible with a role for SKCaR to sense local tubular Mg2+ concentrations. This highly specific distribution of SKCaR protein in dogfish kidney could possibly work in concert with the powerful Mg2+ secretory system present in the PIIa segment of elasmobranch fish kidney to affect recycling of Mg2+ from putative Mg2+-sensing/Mg2+-reabsorbing segments. These data provide support for the possible existence of Mg2+ cycling in elasmobranch kidney in a manner analogous to that described for mammals.

  8. MAP17 Is a Necessary Activator of Renal Na+/Glucose Cotransporter SGLT2

    Science.gov (United States)

    Coady, Michael J.; El Tarazi, Abdulah; Santer, René; Bissonnette, Pierre; Sasseville, Louis J.; Calado, Joaquim; Lussier, Yoann; Dumayne, Christopher; Bichet, Daniel G.

    2017-01-01

    The renal proximal tubule reabsorbs 90% of the filtered glucose load through the Na+-coupled glucose transporter SGLT2, and specific inhibitors of SGLT2 are now available to patients with diabetes to increase urinary glucose excretion. Using expression cloning, we identified an accessory protein, 17 kDa membrane-associated protein (MAP17), that increased SGLT2 activity in RNA-injected Xenopus oocytes by two orders of magnitude. Significant stimulation of SGLT2 activity also occurred in opossum kidney cells cotransfected with SGLT2 and MAP17. Notably, transfection with MAP17 did not change the quantity of SGLT2 protein at the cell surface in either cell type. To confirm the physiologic relevance of the MAP17–SGLT2 interaction, we studied a cohort of 60 individuals with familial renal glucosuria. One patient without any identifiable mutation in the SGLT2 coding gene (SLC5A2) displayed homozygosity for a splicing mutation (c.176+1G>A) in the MAP17 coding gene (PDZK1IP1). In the proximal tubule and in other tissues, MAP17 is known to interact with PDZK1, a scaffolding protein linked to other transporters, including Na+/H+ exchanger 3, and to signaling pathways, such as the A-kinase anchor protein 2/protein kinase A pathway. Thus, these results provide the basis for a more thorough characterization of SGLT2 which would include the possible effects of its inhibition on colocalized renal transporters. PMID:27288013

  9. Exposure of cultured human proximal tubular cells to cadmium, mercury, zinc and bismuth: toxicity and metallothionein induction.

    Science.gov (United States)

    Rodilla, V; Miles, A T; Jenner, W; Hawksworth, G M

    1998-08-14

    The kidney, in particular the proximal convoluted tubule, is a major target site for the toxic effects of various metals. However, little is known about the early effects of these metals after acute exposure in man. In the present study we have evaluated the toxicity of several inorganic metal compounds (CdCl2, HgCl2, ZnCl2, and Bi(NO3)3) and the induction of metallothionein by these compounds in cultured human proximal tubular (HPT) cells for up to 4 days. The results showed that bismuth was not toxic even at the highest dose (100 microM) used, while zinc, cadmium and mercury exhibited varying degrees of toxicity, zinc being the least toxic and mercury the most potent. A significant degree of interindividual variation between the different isolates used in these experiments was also observed. All metals used in the present study induced MT, as revealed by immunocytochemistry. All metals showed maximal induction between 1 and 3 days after treatment. Although a certain amount of constitutive MT was present in the cultures, the intensity of the staining varied with time in culture and between the different isolates studied. No correlation could be made between the intensity of the staining in control cultures (indicating total amount of constitutive MT) and the susceptibility of a given isolate to metal toxicity. Furthermore, no correlation could be made between metal-induced MT and the susceptibility of a given isolate to that particular metal.

  10. Antioxidative effects of fermented sesame sauce against hydrogen peroxide-induced oxidative damage in LLC-PK1 porcine renal tubule cells

    Science.gov (United States)

    Song, Jia-Le; Choi, Jung-Ho; Seo, Jae-Hoon; Kil, Jeung-Ha

    2014-01-01

    BACKGROUND/OBJECTIVES This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide (H2O2)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (•OH), and H2O2 scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against H2O2-induced oxidative damage in LLC-PK1 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation, and endogenous antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) were measured. RESULTS The ability of FSeS to scavenge DPPH, •OH and H2O2 was greater than that of FSS and AHSS. FSeS also significantly inhibited H2O2-induced (500 µM) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P sauces, FSeS also significantly increased cellular CAT, SOD, and GSH-px activities and mRNA expression (P < 0.05). CONCULUSIONS These results from the present study suggest that FSeS is an effective radical scavenger and protects against H2O2-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity. PMID:24741396

  11. Tubule-Derived Wnts Are Required for Fibroblast Activation and Kidney Fibrosis.

    Science.gov (United States)

    Zhou, Dong; Fu, Haiyan; Zhang, Lu; Zhang, Ke; Min, Yali; Xiao, Liangxiang; Lin, Lin; Bastacky, Sheldon I; Liu, Youhua

    2017-08-01

    Cell-cell communication via Wnt ligands is necessary in regulating embryonic development and has been implicated in CKD. Because Wnt ligands are ubiquitously expressed, the exact cellular source of the Wnts involved in CKD remains undefined. To address this issue, we generated two conditional knockout mouse lines in which Wntless (Wls), a dedicated cargo receptor that is obligatory for Wnt secretion, was selectively ablated in tubular epithelial cells or interstitial fibroblasts. Blockade of Wnt secretion by genetic deletion of Wls in renal tubules markedly inhibited myofibroblast activation and reduced renal fibrosis after unilateral ureteral obstruction. This effect associated with decreased activation of β -catenin and downstream gene expression and preserved tubular epithelial integrity. In contrast, fibroblast-specific deletion of Wls exhibited little effect on the severity of renal fibrosis after obstructive or ischemia-reperfusion injury. In vitro , incubation of normal rat kidney fibroblasts with tubule-derived Wnts promoted fibroblast proliferation and activation. Furthermore, compared with kidney specimens from patients without CKD, biopsy specimens from patients with CKD also displayed increased expression of multiple Wnt proteins, predominantly in renal tubular epithelium. These results illustrate that tubule-derived Wnts have an essential role in promoting fibroblast activation and kidney fibrosis via epithelial-mesenchymal communication. Copyright © 2017 by the American Society of Nephrology.

  12. Targeting renal glucose reabsorption to treat hyperglycaemia: the pleiotropic effects of SGLT2 inhibition.

    Science.gov (United States)

    Vallon, Volker; Thomson, Scott C

    2017-02-01

    Healthy kidneys filter ∼160 g/day of glucose (∼30% of daily energy intake) under euglycaemic conditions. To prevent valuable energy from being lost in the urine, the proximal tubule avidly reabsorbs filtered glucose up to a limit of ∼450 g/day. When blood glucose levels increase to the point that the filtered load exceeds this limit, the surplus is excreted in the urine. Thus, the kidney provides a safety valve that can prevent extreme hyperglycaemia as long as glomerular filtration is maintained. Most of the capacity for renal glucose reabsorption is provided by sodium glucose cotransporter (SGLT) 2 in the early proximal tubule. In the absence or with inhibition of SGLT2, the renal reabsorptive capacity for glucose declines to ∼80 g/day (the residual capacity of SGLT1), i.e. the safety valve opens at a lower threshold, which makes it relevant to glucose homeostasis from day-to-day. Several SGLT2 inhibitors are now approved glucose lowering agents for individuals with type 2 diabetes and preserved kidney function. By inducing glucosuria, these drugs improve glycaemic control in all stages of type 2 diabetes, while their risk of causing hypoglycaemia is low because they naturally stop working when the filtered glucose load falls below ∼80 g/day and they do not otherwise interfere with metabolic counterregulation. Through glucosuria, SGLT2 inhibitors reduce body weight and body fat, and shift substrate utilisation from carbohydrates to lipids and, possibly, ketone bodies. Because SGLT2 reabsorbs sodium along with glucose, SGLT2 blockers are natriuretic and antihypertensive. Also, because they work in the proximal tubule, SGLT2 inhibitors increase delivery of fluid and electrolytes to the macula densa, thereby activating tubuloglomerular feedback and increasing tubular back pressure. This mitigates glomerular hyperfiltration, reduces the kidney's demand for oxygen and lessens albuminuria. For reasons that are less well understood, SGLT2 inhibitors are

  13. Morphometry of testis and seminiferous tubules of the adult crab-eating fox (Cerdocyon thous, Linnaeus, 1766

    Directory of Open Access Journals (Sweden)

    Bianca Cabral Caldeira

    2010-10-01

    Full Text Available Body and testicular biometric parameters are very important for establishing reproductive patterns and, consequently, the development of protocols for assisted reproduction in different species. A direct correlation between the testis weight and the sperm population was observed in other studied species, because the testis size primarily reflects the total volume of the seminiferous tubule, its main component. The objective of this study was to determine the testicular volume parameters and correlate data from morphometry of testis and seminiferous tubules with body mass in six adult crab-eating foxes. The mean body weight of the crab-eating foxes in this study was 6.53 kg, with approximately 0.068% allocated to the testicular mass and 0.042% specifically to seminiferous tubules, which represented 87.5% of the testicular parenchyma. The albuginea comprised 12.5% of the testicular mass. The mean diameter of seminiferous tubules was 236 µm, and the mean thickness of the seminiferous epithelium was 62.9 µm. Values of tubular parameters indicate a sperm productivity close to those observed in previously studied carnivores.

  14. Studies on the origin and structure of tubules made by the movement protein of Cowpea mosaic virus

    NARCIS (Netherlands)

    Pouwels, J.; Velden, van der T.; Willemse, J.; Borst, J.W.; Lent, van J.W.M.; Bisseling, T.; Wellink, J.E.

    2004-01-01

    Cowpea mosaic virus (CPMV) moves from cell to cell by transporting virus particles via tubules formed through plasmodesmata by the movement protein (MP). On the surface of protoplasts, a fusion between the MP and the green fluorescent protein forms similar tubules and peripheral punctate spots. Here

  15. Isolation and Characterization of Adhesive Secretion from Cuvierian Tubules of Sea Cucumber Holothuria forskåli (Echinodermata: Holothuroidea

    Directory of Open Access Journals (Sweden)

    Malgorzata Baranowska

    2011-01-01

    Full Text Available The sea cucumber Holothuria forskåli possesses a specialized system called Cuvierian tubules. During mechanical stimulation white filaments (tubules are expelled and become sticky upon contact with any object. We isolated a protein with adhesive properties from protein extracts of Cuvierian tubules from H. forskåli. This protein was identified by antibodies against recombinant precollagen D which is located in the byssal threads of the mussel Mytilus galloprovincialis. To find out the optimal procedure for extraction and purification, the identified protein was isolated by several methods, including electroelution, binding to glass beads, immunoprecipitation, and gel filtration. Antibodies raised against the isolated protein were used for localization of the adhesive protein in Cuvierian tubules. Immunostaining and immunogold electron microscopical studies revealed the strongest immunoreactivity in the mesothelium; this tissue layer is involved in adhesion. Adhesion of Cuvierian tubule extracts was measured on the surface of various materials. The extracted protein showed the strongest adhesion to Teflon surface. Increased adhesion was observed in the presence of potassium and EDTA, while cadmium caused a decrease in adhesion. Addition of antibodies and trypsin abolished the adhesive properties of the extract.

  16. Efficacy of 4 Irrigation Protocols in Killing Bacteria Colonized in Dentinal Tubules Examined by a Novel Confocal Laser Scanning Microscope Analysis.

    Science.gov (United States)

    Azim, Adham A; Aksel, Hacer; Zhuang, Tingting; Mashtare, Terry; Babu, Jegdish P; Huang, George T-J

    2016-06-01

    The aim of this study was to determine the efficiency of 4 irrigation systems in eliminating bacteria in root canals, particularly in dentinal tubules. Roots of human teeth were prepared to 25/04, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation, (2) sonically agitating with EndoActivator, (3) XP Endo finisher, or (4) erbium:yttrium aluminum garnet laser (PIPS) (15 roots/group). The bacterial reduction in the canal was determined by MTT assays. For measuring live versus dead bacteria in the dentinal tubules (4 teeth/group), teeth were split open and stained with LIVE/DEAD BackLight. Coronal, middle, and apical thirds of the canal dentin were scanned by using a confocal laser scanning microscope (CLSM) to determine the ratio of dead/total bacteria in the dentinal tubules at various depths. All 4 irrigation protocols significantly eliminated bacteria in the canal, ranging from 89.6% to 98.2% reduction (P bacteria in the coronal, middle, and apical segments at 50-μm depth. On the other hand, PIPS had the greatest bacterial killing efficiency at the 150-μm depth in all 3 root segments. XP Endo appears to be more efficient than other 3 techniques in disinfecting the main canal space and up to 50 μm deep into the dentinal tubules. PIPS appears to be most effective in killing the bacteria deep in the dentinal tubules. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. The development of enamel tubules during the formation of enamel in the marsupial Monodelphis domestica.

    OpenAIRE

    Sasagawa, I; Ferguson, M W

    1991-01-01

    In Monodelphis domestica, although both processes from odontoblasts and projections from ameloblasts were found in developing enamel, the majority of the contents of enamel tubules were probably processes that originated from odontoblasts. Processes from odontoblasts penetrating into enamel touched part of the ameloblasts in the stage of enamel formation. No specialised cell junctions were seen at the adherence between the two. There were no enamel tubules in the aprismatic and pseudoprismati...

  18. Fabrication of Collagen Gel Hollow Fibers by Covalent Cross-Linking for Construction of Bioengineering Renal Tubules.

    Science.gov (United States)

    Shen, Chong; Zhang, Guoliang; Wang, Qichen; Meng, Qin

    2015-09-09

    Collagen, the most used natural biomacromolecule, has been extensively utilized to make scaffolds for cell cultures in tissue engineering, but has never been fabricated into the configuration of a hollow fiber (HF) for cell culture due to its poor mechanical properties. In this study, renal tubular cell-laden collagen hollow fiber (Col HF) was fabricated by dissolving sacrificial Ca-alginate cores from collagen shells strengthened by carbodiimide cross-linking. The inner/outer diameters of the Col HF were precisely controlled by the flow rates of core alginate/shell collagen solution in the microfluidic device. As found, the renal tubular cells self-assembled into renal tubules with diameters of 50-200 μm post to the culture in Col HF for 10 days. According to the 3D reconstructed confocal images or HE staining, the renal cells appeared as a tight tubular monolayer on the Col HF inner surface, sustaining more 3D cell morphology than the cell layer on the 2D flat collagen gel surface. Moreover, compared with the cultures in either a Transwell or polymer HF membrane, the renal tubules in Col HF exhibited at least 1-fold higher activity on brush border enzymes of alkaline phosphatase and γ-glutamyltransferase, consistent with their gene expressions. The enhancement occurred similarly on multidrug resistance protein 2 and glucose uptake. Such bioengineered renal tubules in Col HF will present great potential as alternatives to synthetic HF in both clinical use and pharmaceutical investigation.

  19. PERK silence inhibits glioma cell growth under low glucose stress by blockage of p-AKT and subsequent HK2's mitochondria translocation

    KAUST Repository

    Hou, Xu; Liu, Yaohua; Liu, Huailei; Chen, Xin; Liu, Min; Che, Hui; Guo, Fei; Wang, Chunlei; Zhang, Daming; Wu, Jianing; Chen, Xiaofeng; Shen, Chen; Li, Chenguang; Peng, Fei; Bi, Yunke; Yang, Zhuowen; Yang, Guang; Ai, Jing; Gao, Xin; Zhao, Shiguang

    2015-01-01

    Glioma relies on glycolysis to obtain energy and sustain its survival under low glucose microenvironment in vivo. The mechanisms on glioma cell glycolysis regulation are still unclear. Signaling mediated by Double-stranded RNA-activated protein kinase (PKR) - like ER kinase (PERK) is one of the important pathways of unfolded protein response (UPR) which is comprehensively activated in cancer cells upon the hypoxic and low glucose stress. Here we show that PERK is significantly activated in human glioma tissues. PERK silencing results in decreased glioma cell viability and ATP/lactate production upon low glucose stress, which is mediated by partially blocked AKT activation and subsequent inhibition of Hexokinase II (HK2)'s mitochondria translocation. More importantly, PERK silenced glioma cells show decreased tumor formation capacity. Our results reveal that PERK activation is involved in glioma glycolysis regulation and may be a potential molecular target for glioma treatment.

  20. PERK silence inhibits glioma cell growth under low glucose stress by blockage of p-AKT and subsequent HK2's mitochondria translocation

    KAUST Repository

    Hou, Xu

    2015-03-12

    Glioma relies on glycolysis to obtain energy and sustain its survival under low glucose microenvironment in vivo. The mechanisms on glioma cell glycolysis regulation are still unclear. Signaling mediated by Double-stranded RNA-activated protein kinase (PKR) - like ER kinase (PERK) is one of the important pathways of unfolded protein response (UPR) which is comprehensively activated in cancer cells upon the hypoxic and low glucose stress. Here we show that PERK is significantly activated in human glioma tissues. PERK silencing results in decreased glioma cell viability and ATP/lactate production upon low glucose stress, which is mediated by partially blocked AKT activation and subsequent inhibition of Hexokinase II (HK2)\\'s mitochondria translocation. More importantly, PERK silenced glioma cells show decreased tumor formation capacity. Our results reveal that PERK activation is involved in glioma glycolysis regulation and may be a potential molecular target for glioma treatment.

  1. Hypertension Knowledge-Level Scale (HK-LS): A Study on Development, Validity and Reliability

    OpenAIRE

    Erkoc, Sultan Baliz; Isikli, Burhanettin; Metintas, Selma; Kalyoncu, Cemalettin

    2012-01-01

    This study was conducted to develop a scale to measure knowledge about hypertension among Turkish adults. The Hypertension Knowledge-Level Scale (HK-LS) was generated based on content, face, and construct validity, internal consistency, test re-test reliability, and discriminative validity procedures. The final scale had 22 items with six sub-dimensions. The scale was applied to 457 individuals aged ≥18 years, and 414 of them were re-evaluated for test-retest reliability. The six sub-dimensio...

  2. In vitro remineralization of enamel subsurface lesions and assessment of dentine tubule occlusion from NaF dentifrices with and without calcium

    Directory of Open Access Journals (Sweden)

    A R Prabhakar

    2013-01-01

    Full Text Available Currently, fluoride is the most effective preventive treatment for remineralization of incipient carious lesions and dentinal hypersensitivity due to wasting disorders. The products containing fluoride, calcium and phosphate are also claim to remineralize early, non-cavitated enamel demineralization. The aim of this study was to investigate and compare the efficacy of two such products, Tooth Mousse and Clinpro tooth crème on remineralization and tubule occluding ability with 5000ppm fluoride-containing toothpaste. Materials and Methods :Thirty third molar teeth were placed in demineralizing solution for 5 days such that only a window of 1mm x 5mm was exposed to the environment to produce artificial caries-like lesions and randomly assigned to three groups: Group I, 5000ppm sodium fluoride; Group II, GC MI paste plus and Group III, Clinpro tooth crème. Axial longitudinal sections of 140-160 μm of each tooth which included the artificial carious lesion taken and were photographed under polarized light microscope. The demineralized areas were then quantified with a computerized imaging system. The experimental materials were applied onto the tooth sections as a topical coating and subjected to pH-cycling for 28 days. To evaluate tubule occlusion ability, thirty dentin specimens of 2mm thickness were obtained from cervical third of sound third molars. Specimens were ultrasonicated and etched with 6% citric acid for 2 minutes to simulate the hypersensitive dentin. Specimens were randomly divided into above mentioned three groups (n=10. The test agents were brushed over the specimens with an electric toothbrush, prepared and observed under Scanning Electron Microscope for calculation of the percentage of occluded tubules. Results: Group I showed a significantly greater percentage of remineralization than Group III and Group II. Comparison of the remineralization potential between group II and group III were not significant.In case of dentine

  3. Reactive Oxygen Species Modulation of Na/K-ATPase Regulates Fibrosis and Renal Proximal Tubular Sodium Handling

    Directory of Open Access Journals (Sweden)

    Jiang Liu

    2012-01-01

    Full Text Available The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase activity, its signaling, fibrosis, and RPT sodium reabsorption.

  4. Automated tubule nuclei quantification and correlation with oncotype DX risk categories in ER+ breast cancer whole slide images

    Science.gov (United States)

    Romo-Bucheli, David; Janowczyk, Andrew; Romero, Eduardo; Gilmore, Hannah; Madabhushi, Anant

    2016-03-01

    Early stage estrogen receptor positive (ER+) breast cancer (BCa) treatment is based on the presumed aggressiveness and likelihood of cancer recurrence. The primary conundrum in treatment and management of early stage ER+ BCa is identifying which of these cancers are candidates for adjuvant chemotherapy and which patients will respond to hormonal therapy alone. This decision could spare some patients the inherent toxicity associated with adjuvant chemotherapy. Oncotype DX (ODX) and other gene expression tests have allowed for distinguishing the more aggressive ER+ BCa requiring adjuvant chemotherapy from the less aggressive cancers benefiting from hormonal therapy alone. However these gene expression tests tend to be expensive, tissue destructive and require physical shipping of tissue blocks for the test to be done. Interestingly breast cancer grade in these tumors has been shown to be highly correlated with the ODX risk score. Unfortunately studies have shown that Bloom-Richardson (BR) grade determined by pathologists can be highly variable. One of the constituent categories in BR grading is the quantification of tubules. The goal of this study was to develop a deep learning neural network classifier to automatically identify tubule nuclei from whole slide images (WSI) of ER+ BCa, the hypothesis being that the ratio of tubule nuclei to overall number of nuclei would correlate with the corresponding ODX risk categories. The performance of the tubule nuclei deep learning strategy was evaluated with a set of 61 high power fields. Under a 5-fold cross-validation, the average precision and recall measures were 0:72 and 0:56 respectively. In addition, the correlation with the ODX risk score was assessed in a set of 7513 high power fields extracted from 174 WSI, each from a different patient (At most 50 high power fields per patient study were used). The ratio between the number of tubule and non-tubule nuclei was computed for each WSI. The results suggests that for BCa

  5. Effect of Naphthalene and Salicylate Analogues on the Bioluminescence of Bioreporter Pseudomonas Fluorescens HK44.

    Czech Academy of Sciences Publication Activity Database

    Trögl, Josef; Kuncová, Gabriela; Kubicová, L.; Pařík, P.; Hálová, Jaroslava; Demnerová, K.; Ripp, S.; Sayler, G. S.

    2007-01-01

    Roč. 52, 1 (2007) , s. 3-14 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA104/05/2637; GA ČR(CZ) GA203/06/1244 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : pseudomonas fluorescens HK44 * bioluminescence * bioluminescence Subject RIV: CE - Biochemistry Impact factor: 0.989, year: 2007

  6. Permeation of macromolecules into the renal glomerular basement membrane and capture by the tubules

    Science.gov (United States)

    Lawrence, Marlon G.; Altenburg, Michael K.; Sanford, Ryan; Willett, Julian D.; Bleasdale, Benjamin; Ballou, Byron; Wilder, Jennifer; Li, Feng; Miner, Jeffrey H.; Berg, Ulla B.; Smithies, Oliver

    2017-01-01

    How the kidney prevents urinary excretion of plasma proteins continues to be debated. Here, using unfixed whole-mount mouse kidneys, we show that fluorescent-tagged proteins and neutral dextrans permeate into the glomerular basement membrane (GBM), in general agreement with Ogston's 1958 equation describing how permeation into gels is related to molecular size. Electron-microscopic analyses of kidneys fixed seconds to hours after injecting gold-tagged albumin, negatively charged gold nanoparticles, and stable oligoclusters of gold nanoparticles show that permeation into the lamina densa of the GBM is size-sensitive. Nanoparticles comparable in size with IgG dimers do not permeate into it. IgG monomer-sized particles permeate to some extent. Albumin-sized particles permeate extensively into the lamina densa. Particles traversing the lamina densa tend to accumulate upstream of the podocyte glycocalyx that spans the slit, but none are observed upstream of the slit diaphragm. At low concentrations, ovalbumin-sized nanoparticles reach the primary filtrate, are captured by proximal tubule cells, and are endocytosed. At higher concentrations, tubular capture is saturated, and they reach the urine. In mouse models of Pierson’s or Alport’s proteinuric syndromes resulting from defects in GBM structural proteins (laminin β2 or collagen α3 IV), the GBM is irregularly swollen, the lamina densa is absent, and permeation is increased. Our observations indicate that size-dependent permeation into the lamina densa of the GBM and the podocyte glycocalyx, together with saturable tubular capture, determines which macromolecules reach the urine without the need to invoke direct size selection by the slit diaphragm. PMID:28246329

  7. Structural and functional alterations in Malpighian tubules as biomarkers of environmental pollution: synopsis and prospective.

    Science.gov (United States)

    Giglio, Anita; Brandmayr, Pietro

    2017-08-01

    Although a number of biomarkers of pollutant exposure have been identified in invertebrate species, little is known about the effect on Malpighian tubules playing an essential role in excretion and osmoregulation. Analyses of structural and functional alterations on this organ can be useful to predict the effects at the organism and population level in monitoring studies of environmental pollution. The aim of the present review is to provide a synthesis of existing knowledge on cellular damages induced by xenobiotics in Malpighian tubules both under laboratory and field conditions. We compared studies of exposure to pesticides and heavy metals as mainly environmental contaminants from anthropogenic activities. This report provided evidence that the exposure to xenobiotics has an effect on this organ and reinforces the need for further research integrating molecular biomarkers with analysis on Malpighian tubules. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Finanční analýza podniku Matex HK s.r.o.

    OpenAIRE

    Matyáš, Petr

    2009-01-01

    Financial analysis of company is very important instrument of corporate affairs. My work deals with complex financial analysis of company Matex HK s.r.o. since 2004 till 2008. I primarily focus on horizontal and vertical analysis, ration and distance indicators analysis, EVA analysis, ROE analysis and I discover by the help of models of bankruptcy if company is threatened by bankrupt. I judge too, if company is run by some recommended rules, example by gold balance rules. Next I accentuate on...

  9. Effects of bioactive glass with and without mesoporous structures on desensitization in dentinal tubule occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Kung, Jung-Chang [Department of Family Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chen, Cheng-Hwei [School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Hsiao, Yu-Cheng [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Shih, Chi-Jen, E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chien, Chi-Sheng, E-mail: jannie.gissing@msa.hinet.net [Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Department of Orthopaedics, Chi Mei Foundation Hospital, Tainan, Taiwan (China); Department of Electrical Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China)

    2013-10-15

    Bioactive glass (BG) is a potential material for treating dentin hypersensitivity due to its high ability of dissolution. In this study, conventional BG and BG with well-ordered mesopore structures (MBG) were applied for dentinal tubule occlusion. We used X-ray diffractometer (XRD), scanning electronic microscope (SEM), and Fourier transform infrared (FTIR) to investigate the physiochemical properties and the dentinal tubule occlusion ability of BG and MBG groups. The results showed that the major crystallite phase of MBG and BG agents was monocalcium phosphate monohydrate. MBG pastes, mixed with 30 and 40 wt% phosphoric acid hardening solutions, had the ability to create a penetration depth greater than 50 μm. These results showed that BG with mesoporous structures turned the pastes mixed with suitable phosphoric acid solution into a material with great ability for occluding dentinal tubules; it has a short reaction time and good operability, and these agents have better potential for the treatment of dentin hypersensitivity than BG without mesoporous structures.

  10. Effects of bioactive glass with and without mesoporous structures on desensitization in dentinal tubule occlusion

    International Nuclear Information System (INIS)

    Chen, Wen-Cheng; Kung, Jung-Chang; Chen, Cheng-Hwei; Hsiao, Yu-Cheng; Shih, Chi-Jen; Chien, Chi-Sheng

    2013-01-01

    Bioactive glass (BG) is a potential material for treating dentin hypersensitivity due to its high ability of dissolution. In this study, conventional BG and BG with well-ordered mesopore structures (MBG) were applied for dentinal tubule occlusion. We used X-ray diffractometer (XRD), scanning electronic microscope (SEM), and Fourier transform infrared (FTIR) to investigate the physiochemical properties and the dentinal tubule occlusion ability of BG and MBG groups. The results showed that the major crystallite phase of MBG and BG agents was monocalcium phosphate monohydrate. MBG pastes, mixed with 30 and 40 wt% phosphoric acid hardening solutions, had the ability to create a penetration depth greater than 50 μm. These results showed that BG with mesoporous structures turned the pastes mixed with suitable phosphoric acid solution into a material with great ability for occluding dentinal tubules; it has a short reaction time and good operability, and these agents have better potential for the treatment of dentin hypersensitivity than BG without mesoporous structures.

  11. Denervation and high-fat diet reduce insulin signaling in T-tubules in skeletal muscle of living mice

    DEFF Research Database (Denmark)

    Lauritzen, Hans P M; Ploug, Thorkil; Ai, Hua

    2008-01-01

    OBJECTIVE: Insulin stimulates muscle glucose transport by translocation of GLUT4 to sarcolemma and T-tubules. Despite muscle glucose uptake playing a major role in insulin resistance and type 2 diabetes, the temporal and spatial changes in insulin signaling and GLUT4 translocation during these co...

  12. Role of delta-tubulin and the C-tubule in assembly of Paramecium basal bodies

    Directory of Open Access Journals (Sweden)

    Beisson Janine

    2001-03-01

    Full Text Available Abstract Background A breakthrough in the understanding of centriole assembly was provided by the characterization of the UNI3 gene in Chlamydomonas. Deletion of this gene, found to encode a novel member of the tubulin superfamily, delta-tubulin, results in the loss of the C-tubule, in the nine microtubule triplets which are the hallmark of centrioles and basal bodies. Delta-tubulin homologs have been identified in the genomes of mammals and protozoa, but their phylogenetic relationships are unclear and their function is not yet known. Results Using the method of gene-specific silencing, we have inactivated the Paramecium delta-tubulin gene, which was recently identified. This inactivation leads to loss of the C-tubule in all basal bodies, without any effect on ciliogenesis. This deficiency does not directly affect basal body duplication, but perturbs the cortical cytoskeleton, progressively leading to mislocalization and loss of basal bodies and to altered cell size and shape. Furthermore, additional loss of B- and even A-tubules at one or more triplet sites are observed: around these incomplete cylinders, the remaining doublets are nevertheless positioned according to the native ninefold symmetry. Conclusions The fact that in two distinct phyla, delta-tubulin plays a similar role provides a new basis for interpreting phylogenetic relationships among delta-tubulins. The role of delta-tubulin in C-tubule assembly reveals that tubulins contribute subtle specificities at microtubule nucleation sites. Our observations also demonstrate the existence of a prepattern for the ninefold symmetry of the organelle which is maintained even if less than 9 triplets develop.

  13. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    Energy Technology Data Exchange (ETDEWEB)

    McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Chornock, Ryan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Holtzman, Jon A. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Balam, David D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Branch, David [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Frieman, Joshua [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Fynbo, Johan; Leloudas, Giorgos [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Galbany, Lluis [Institut de Física d' Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Leonard, Douglas C., E-mail: cmccully@physics.rutgers.edu [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); and others

    2014-05-10

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n{sub e} ≳ 10{sup 9} cm{sup –3}. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  14. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    International Nuclear Information System (INIS)

    McCully, Curtis; Jha, Saurabh W.; Foley, Ryan J.; Chornock, Ryan; Holtzman, Jon A.; Balam, David D.; Branch, David; Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong; Frieman, Joshua; Fynbo, Johan; Leloudas, Giorgos; Galbany, Lluis; Garnavich, Peter M.; Graham, Melissa L.; Hsiao, Eric Y.; Leonard, Douglas C.

    2014-01-01

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n e ≳ 10 9 cm –3 . Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  15. Hubble Space Telescope and Ground-Based Observations of the Type Iax Supernovae SN 2005hk and SN 2008A

    Energy Technology Data Exchange (ETDEWEB)

    McCully, Curtis; Jha, Saurabh W.; Foley, Ryan J.; Chornock, Ryan; Holtzman, Jon A.; Balam, David D.; Branch, David; Filippenko, Alexei V.; Frieman, Joshua; Fynbo, Johan; Galbany, Lluis; Ganeshalingam, Mohan; Garnavich, Peter M.; Graham, Melissa L.; Hsiao, Eric Y.; Leloudas, Giorgos; Leonard, Douglas C.; Li, Weidong; Riess, Adam G.; Sako, Masao; Schneider, Donald P.; Silverman, Jeffrey M.; Sollerman, Jesper; Steele, Thea N.; Thomas, Rollin C.; Wheeler, J. Craig; Zheng, Chen

    2014-04-24

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with ne109 cm–3. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected "infrared catastrophe," a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a "complete deflagration" that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  16. Salicylic acid degradation from aqueous solutions using Pseudomonas fluorescens HK44: parameters studies and application tools Degradação de ácido salicílico presente em soluções sintéticas utilizando Pseudomonas fluorescens HK44

    Directory of Open Access Journals (Sweden)

    Tatyane R. Silva

    2007-03-01

    Full Text Available The optimal conditions for salicylic acid biodegradation by Pseudomonas fluorescens HK44 were determined in this study with the intention to create a microbial sensor. Kinetic experiments permitted a definition of 60 and 30min the time needed to achieve the maximum degradation of salicylic acid presented in a medium with and without yeast extract, respectively. The degradation in medium without yeast extract and the quantification by spectrophotometry 230 nm were selected to be used in further tests. The use of preactivated cells or on the exponential growth phase showed better salicylic acid degradation percentages when compared to nonactivated cells or on the stationary growth state. Finally, the best cellular concentration used on the salicylic acid degradation was 0,1 g.L-1. Strain HK44 shows to be capable of degrade salicylic acid presented in simple aqueous systems, making this strain a promising tool for the application on a luminescent microbial sensor.Com a intenção de criar um sensor microbiano, as condições ótimas para a biodegradação de ácido salicílico por Pseudomonas fluorescens HK44 foram determinadas neste estudo. Os experimentos cinéticos permitiram a definição dos tempos de 60 e 30 minutos como necessários para atingir a máxima degradação de ácido salicílico presente em meio com ou sem extrato de lêvedo, respectivamente. A degradação no meio sem extrato de lêvedo e a quantificação através de espectrofotometria 230 nm foram selecionadas para serem utilizadas em testes posteriores. O uso de células pré-ativadas ou na fase exponencial de crescimento apresentou melhores porcentagens de degradação de ácido salicílico quando comparadas a células não-ativadas ou no estado estacionário de crescimento. Além disso, a melhor concentração celular utilizada nessa degradação foi 0,1 g.L¹. A cepa HK44 parece ser capaz de degradar o ácido salicílico presente em sistemas aquosos simples, tornando este

  17. Destruction and regeneration of seminiferous tubules after local x-irradiation of testes of the adult rats

    International Nuclear Information System (INIS)

    Kurnosova, T.R.; Rajtsina, S.S.

    1987-01-01

    It was established that the local X-irradiation (1000 R) of testes of the adult rats results in a total destruction of seminiferous tubules. The restitution of the organ structure proceeds via formation of new seminiferous tubules in which spermatogenic epithelium later develops. Rete testis and germ cells preserved in its epithelium from embryogenesis are a source of regeneration material. The results obtained favour the suggestion about the dynamic structure of mammalian testis

  18. Dentinal tubule occluding capability of nano-hydroxyapatite; The in-vitro evaluation.

    Science.gov (United States)

    Baglar, Serdar; Erdem, Umit; Dogan, Mustafa; Turkoz, Mustafa

    2018-04-29

    In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1-no treatment (control), 2-specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F - doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F - . The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F - doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F - doped materials may be used as an active ingredient in dentin hypersensitivity agents. © 2018 Wiley Periodicals, Inc.

  19. The Influence of Concentration and Temperature on the Formation of γ-Oryzanol + β-Sitosterol Tubules in Edible Oil Organogels.

    Science.gov (United States)

    Sawalha, Hassan; Venema, Paul; Bot, Arjen; Flöter, Eckhard; van der Linden, Erik

    2011-03-01

    The gelation process of mixtures of γ-oryzanol and sitosterol structurants in sunflower oil was studied using light scattering, rheology, and micro-scanning calorimetry (Micro-DSC). The relation between temperature and the critical aggregation concentration (CAC) of tubule formation of γ-oryzanol and sitosterol was determined using these techniques. The temperature dependence of the CAC was used to estimate the binding energy and enthalpic and entropic contribution to the tubular formation process. The binding energy calculated at the corresponding temperatures and CACs were relatively low, in order of 2 RT (4.5 kJ mol(-1)), which is in accord with the reversibility of the tubular formation process. The formation of the tubules was associated with negative (exothermic) enthalpy change (ΔH(0)) compared with positive entropy term (-T ΔS(0) >0), indicating that the aggregation into tubules is an enthalpy-driven process. The oryzanol-sitosterol ratio affected the aggregation process; solutions with ratio of (60 oryzanol-40 sitosterol) started aggregation at higher temperature compared with other ratios.

  20. Desmoglein 2 is a substrate of kallikrein 7 in pancreatic cancer

    International Nuclear Information System (INIS)

    Ramani, Vishnu C; Hennings, Leah; Haun, Randy S

    2008-01-01

    In a previous report we have demonstrated that the chymotryptic-like serine protease kallikrein 7 (KLK7/hK7) is overexpressed in pancreatic cancer. In normal skin, hK7 is thought to participate in skin desquamation by contributing in the degradation of desmosomal components, such as desmogleins. Thus, the ability of hK7 to degrade desmogleins was assessed and the effect of hK7 expression on desmoglein 2 was examined in cultured pancreatic cancer cells. The expression of Dsg1, Dsg2, and Dsg3 in pancreatic tissues was examined by immunohistochemistry and their expression in two pancreatic cancer cell lines, BxPC-3 and Panc-1, was determined by western blot analysis. The ability of hK7 to degrade Dsg1 and Dsg2 was investigated using in vitro degradation assays. BxPC-3 cells stably transfected to overexpress hK7 were used to examine the effect of hK7 on cell-surface resident Dsg2. The levels of immunoreactive Dsg1 and Dsg2 were reduced in pancreatic adenocarcinomas compared with both normal pancreatic and chronic pancreatitis tissues. Among the desmosomal proteins examined, Dsg2 exhibited robust expression on the surface of BxPC-3 cells. When hK7 was overexpressed in this cell line, there was a significant increase in the amount of soluble Dsg2 released into the culture medium compared with vector-transfected control cells. A reduction in the amount of the cell adhesion components Dsg1 and Dsg2 in pancreatic tumors suggests that loss of these desmosomal proteins may play a role in pancreatic cancer invasion. Using in vitro degradation assays, both Dsg1 and Dsg2 could be readily proteolyzed by hK7, which is overexpressed in pancreatic adenocarcinomas. The enforced expression of hK7 in BxPC-3 cells that express significant amounts of Dsg2 resulted in a marked increase in the shedding of soluble Dsg2, which is consistent with the notion that aberrant expression of hK7 in pancreatic tumors may result in diminished cell-cell adhesion and facilitate tumor cell invasion

  1. Disruption of Core Planar Cell Polarity Signaling Regulates Renal Tubule Morphogenesis but Is Not Cystogenic.

    Science.gov (United States)

    Kunimoto, Koshi; Bayly, Roy D; Vladar, Eszter K; Vonderfecht, Tyson; Gallagher, Anna-Rachel; Axelrod, Jeffrey D

    2017-10-23

    Oriented cell division (OCD) and convergent extension (CE) shape developing renal tubules, and their disruption has been associated with polycystic kidney disease (PKD) genes, the majority of which encode proteins that localize to primary cilia. Core planar cell polarity (PCP) signaling controls OCD and CE in other contexts, leading to the hypothesis that disruption of PCP signaling interferes with CE and/or OCD to produce PKD. Nonetheless, the contribution of PCP to tubulogenesis and cystogenesis is uncertain, and two major questions remain unanswered. Specifically, the inference that mutation of PKD genes interferes with PCP signaling is untested, and the importance of PCP signaling for cystogenic PKD phenotypes has not been examined. We show that, during proliferative stages, PCP signaling polarizes renal tubules to control OCD. However, we find that, contrary to the prevailing model, PKD mutations do not disrupt PCP signaling but instead act independently and in parallel with PCP signaling to affect OCD. Indeed, PCP signaling that is normally downregulated once development is completed is retained in cystic adult kidneys. Disrupting PCP signaling results in inaccurate control of tubule diameter, a tightly regulated parameter with important physiological ramifications. However, we show that disruption of PCP signaling is not cystogenic. Our results suggest that regulating tubule diameter is a key function of PCP signaling but that loss of this control does not induce cysts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Utility of Iron Staining in Identifying the Cause of Renal Allograft Dysfunction in Patients with Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    Yingchun Wang

    2015-01-01

    Full Text Available Sickle cell nephropathy (SCN is associated with iron/heme deposition in proximal renal tubules and related acute tubular injury (ATI. Here we report the utility of iron staining in differentiating causes of renal allograft dysfunction in patients with a history of sickle cell disease. Case 1: the patient developed acute allograft dysfunction two years after renal transplant. Her renal biopsy showed ATI, supported by patchy loss of brush border and positive staining of kidney injury molecule-1 in proximal tubular epithelial cells, where diffuse increase in iron staining (2+ was present. This indicated that ATI likely resulted from iron/heme toxicity to proximal tubules. Electron microscope confirmed aggregated sickle RBCs in glomeruli, indicating a recurrent SCN. Case 2: four years after renal transplant, the patient developed acute allograft dysfunction and became positive for serum donor-specific antibody. His renal biopsy revealed thrombotic microangiopathy (TMA and diffuse positive C4d stain in peritubular capillaries. Iron staining was negative in the renal tubules, implying that TMA was likely associated with acute antibody-mediated rejection (AAMR, type 2 rather than recurrent SCN. These case reports imply that iron staining is an inexpensive but effective method in distinguishing SCN-associated renal injury in allograft kidney from other etiologies.

  3. Dry heat tolerance of the dry colony in Nostoc sp. HK-01 for useful usage in space agriculture

    Science.gov (United States)

    Kimura, Shunta; Tomita-Yokotani, Kaori; Yamashita, Masamichi; Sato, Seigo; Katoh, Hiroshi

    Space agriculture producing foods is important as one of approach for space habitation. Nostoc sp. HK-01 is one of terrestrial cyanobacterium having a high dry tolerance and it has several ability, photosynthesis, nitrogen fixation and usefulness as a food, it is thought that it can be used for space agriculture. Besides, a study on each tolerance predicted at the time of introduction to space agriculture is necessary. Therefore, as one of the tolerance that are intended to space environment, dry heat ( 100(°) C, 10 h ) tolerance of dry colony in Nostoc sp. HK-01 has been investigated, but the detail function of them has not yet been elucidated. We focused on the extracellular polysaccharides ( EPS ) having the various tolerance, desiccation, low temperature, NaCl, and heavy particle beam. We will consider the function and useful usage of this cyanobacterum in space agriculture after the consideration of the results of contribution of the possibility that EPS improves dry heat tolerance under a dry condition.

  4. The Single Kinin Receptor Signals to Separate and Independent Physiological Pathways in Malpighian Tubules of the Yellow Fever Mosquito

    Science.gov (United States)

    2010-06-10

    mortar and pestle . On the day of the experiment a female mosquito, 4-7 days post-eclosion, was cold anesthetized and decapitated. Malpighian tubules...tubules was analyzed with the electron probe as described previously (7, 62), except that we used the JEOL JXA 8900 EPMA Microprobe (Tokyo, Japan

  5. Minicollagen-15, a novel minicollagen isolated from Hydra, forms tubule structures in nematocysts.

    Science.gov (United States)

    Adamczyk, Patrizia; Meier, Sebastian; Gross, Thomas; Hobmayer, Bert; Grzesiek, Stephan; Bächinger, Hans Peter; Holstein, Thomas W; Ozbek, Suat

    2008-02-29

    Minicollagens constitute a family of unusually short collagen molecules isolated from cnidarians. They are restricted to the nematocyst, a cylindrical explosive organelle serving in defense and capture of prey. The nematocyst capsule contains a long tubule inside of its matrix, which is expelled and everted during an ultrafast discharge process. Here, we report the cloning and characterization of a novel minicollagen in Hydra, designated minicollagen-15 (NCol-15). NCol-15, like NCol-3 and NCol-4, shows deviations from the canonical cysteine pattern in its terminal cysteine-rich domains (CRDs). Minicollagens share common domain architectures with a central collagen sequence flanked by polyproline stretches and short N- and C-terminal CRDs. The CRDs are involved in the formation of a highly resistant cysteine network, which constitutes the basic structure of the nematocyst capsule. Unlike NCol-1, which is part of the capsule wall, NCol-15 is localized to tubules, arguing for a functional differentiation of minicollagens within the nematocyst architecture. NMR analysis of the altered C-terminal CRD of NCol-15 showed a novel disulfide-linked structure within the cysteine-containing region exhibiting similar folding kinetics and stability as the canonical CRDs. Our data provide evidence for evolutionary diversification among minicollagens, which probably facilitated alterations in the morphology of the nematocyst wall and tubule.

  6. Pathophysiological aspect of metabolic acid-base disorders

    Directory of Open Access Journals (Sweden)

    Nešović-Ostojić Jelena

    2016-01-01

    Full Text Available Maintaing the arterial pH values (in normal range of 7,35-7,45 is one of the main principles of homeostasis. Regulatory responses, including chemical buffering (extracellular, intracellular, sceletal, the regulation of pCO2 by the respiratory system, and the regulation of [HCO3-] by the kidneys, act in concert to maintain normal arterial pH value. The main extracellular chemical buffer is bicarbonate-carbonic acid buffer system. The kidneys contribute to the regulation of hydrogen (and bicarbonate in body fluids in two ways. Proximal tubules are important in bicarbonate reabsorption and distal tubules excrete hydrogen ion (as ammonium ion or titratable acid. There are four simple acid-base disorders: metabolic acidosis and metabolic alkalosis; respiratory acidosis and respiratory alkalosis. Metabolic acidosis can occur because of an increase in endogenous acid production (such as lactate and ketoacids, loss of bicarbonate (as in diarrhea, or accumulation of endogenous acids (as in renal failure. Metabolic acidosis can also be with high and normal (hyperchloremic metabolic acidosis anion gap. Renal tubular acidosis (RTA is a form of hyperchloremic metabolic acidosis which occurs when the renal damage primarily affects tubular function. The main problem in distal RTA is reduced H+ excretion in distal tubule. Type 2 RTA is also called proximal RTA because the main problem is greatly impaired reabsorption of bicarbonate in proximal tubule. Impaired cation exchange in distal tubule is the main problem in RTA type 4. Metabolic alkalosis occurs as a result of net gain of [HCO3-] or loss of nonvolatile acid from extracellular fluids. Metabolic alkalosis can be associated with reduced or increased extracellular volume.

  7. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    Science.gov (United States)

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis.

  8. Reconstruction of mouse testicular cellular microenvironments in long-term seminiferous tubule culture.

    Directory of Open Access Journals (Sweden)

    Juho-Antti Mäkelä

    Full Text Available Research on spermatogonia is hampered by complex architecture of the seminiferous tubule, poor viability of testicular tissue ex vivo and lack of physiologically relevant long-term culture systems. Therefore there is a need for an in vitro model that would enable long term survival and propagation of spermatogonia. We aimed at the most simplified approach to enable all different cell types within the seminiferous tubules to contribute to the creation of a niche for spermatogonia. In the present study we describe the establishment of a co-culture of mouse testicular cells that is based on proliferative and migratory activity of seminiferous tubule cells and does not involve separation, purification or differential plating of individual cell populations. The co-culture is composed of the constituents of testicular stem cell niche: Sertoli cells [identified by expression of Wilm's tumour antigen 1 (WT1 and secretion of glial cell line-derived neurotrophic factor, GDNF], peritubular myoid cells (expressing alpha smooth muscle actin, αSMA and spermatogonia [expressing MAGE-B4, PLZF (promyelocytic leukaemia zinc finger, LIN28, Gpr125 (G protein-coupled receptor 125, CD9, c-Kit and Nanog], and can be maintained for at least five weeks. GDNF was found in the medium at a sufficient concentration to support proliferating spermatogonial stem cells (SSCs that were able to start spermatogenic differentiation after transplantation to an experimentally sterile recipient testis. Gdnf mRNA levels were elevated by follicle-stimulating hormone (FSH which shows that the Sertoli cells in the co-culture respond to physiological stimuli. After approximately 2-4 weeks of culture a spontaneous formation of cord-like structures was monitored. These structures can be more than 10 mm in length and branch. They are formed by peritubular myoid cells, Sertoli cells, fibroblasts and spermatogonia as assessed by gene expression profiling. In conclusion, we have managed to

  9. Aging Selectively Modulates Vitamin C Transporter Expression Patterns in the Kidney.

    Science.gov (United States)

    Forman, Katherine; Martínez, Fernando; Cifuentes, Manuel; Bertinat, Romina; Salazar, Katterine; Nualart, Francisco

    2017-09-01

    In the kidney, vitamin C is reabsorbed from the glomerular ultrafiltrate by sodium-vitamin C cotransporter isoform 1 (SVCT1) located in the brush border membrane of the proximal tubules. Although we know that vitamin C levels decrease with age, the adaptive physiological mechanisms used by the kidney for vitamin C reabsorption during aging remain unknown. In this study, we used an animal model of accelerated senescence (SAMP8 mice) to define the morphological alterations and aging-induced changes in the expression of vitamin C transporters in renal tissue. Aging induced significant morphological changes, such as periglomerular lymphocytic infiltrate and glomerular congestion, in the kidneys of SAMP8 mice, although no increase in collagen deposits was observed using 2-photon microscopy analysis and second harmonic generation. The most characteristic histological alteration was the dilation of intracellular spaces in the basolateral region of proximal tubule epithelial cells. Furthermore, a combination of laser microdissection, qRT-PCR, and immunohistochemical analyses allowed us to determine that SVCT1 expression specifically increased in the proximal tubules from the outer strip of the outer medulla (segment S3) and cortex (segment S2) during aging and that these tubules also express GLUT1. We conclude that aging modulates vitamin C transporter expression and that renal over-expression of SVCT1 enhances vitamin C reabsorption in aged animals that may synthesize less vitamin C. J. Cell. Physiol. 232: 2418-2426, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Scattering of neutrons by catalase: a study of molecules, subunits, and tubules

    International Nuclear Information System (INIS)

    Randall, J.; Starling, D.; Baldwin, J.P.; Ibel, K.

    1976-01-01

    The paper deals with small-angle scattering of neutrons by catalase tetramers, dimers, and monomers and with neutron diffraction by helical assemblies of tetramers in the form of tubules. A preliminary study of catalase is described

  11. Chloride secretagogues stimulate inositol phosphate formation in shark rectal gland tubules cultured in suspension

    International Nuclear Information System (INIS)

    Ecay, T.W.; Valentich, J.D.

    1991-01-01

    Neuroendocrine activation of transepithelial chloride secretion by shark rectal gland cells is associated with increases in cellular cAMP, cGMP, and free calcium concentrations. We report here on the effects of several chloride secretagogues on inositol phosphate formation in cultured rectal gland tubules. Vasoactive intestinal peptide (VIP), atriopeptin (AP), and ionomycin increase the total inositol phosphate levels of cultured tubules, as measured by ion exchange chromatography. Forskolin, a potent chloride secretagogue, has no effect on inositol phosphate formation. The uptake of 3 H-myo-inositol into phospholipids is very slow, preventing the detection of increased levels of inositol trisphosphate. However, significant increases in inositol monophosphate (IP1) and inositol biphosphate (IP2) were measured. The time course of VIP- and AP-stimulated IP1 and IP2 formation is similar to the effects of these agents on the short-circuit current responses of rectal gland monolayer cultures. In addition, aluminum fluoride, an artificial activator of guanine nucleotide-binding proteins, stimulates IP1 and IP2 formation. We conclude that rectal gland cells contain VIP and AP receptors coupled to the activation of phospholipase C. Coupling may be mediated by G-proteins. Receptor-stimulated increases in inositol phospholipid metabolism is one mechanism leading to increased intracellular free calcium concentrations, an important regulatory event in the activation of transepithelial chloride secretion by shark rectal gland epithelial cells

  12. Human organic cation transporter 2 (hOCT2): Inhibitor studies using S2-hOCT2 cells

    International Nuclear Information System (INIS)

    Chiba, Shoetsu; Ikawa, Toru; Takeshita, Hiroshi; Kanno, Sanae; Nagai, Tomonori; Takada, Meri; Mukai, Toshiji; Wempe, Michael F.

    2013-01-01

    Highly expressed in kidney and located on the basolateral membrane, human organic cation transporter 2 (hOCT2) can transport various compounds (i.e. drugs and toxins) into the proximal tubular cell. Using cultured proximal tubule cells stably expressing hOCT2 (i.e. S2-hOCT2 cells), we sought to probe different compound classes (e.g. analgesics, anti-depressants, anti-psychotics, disinfectant, herbicides, insecticides, local anesthetic, muscarinic acetylcholine receptor antagonist, sedatives, steroid hormone, stimulants and toxins) for their ability to inhibit 14 C-TEA uptake, a prototypical OCT2 substrate. Aconitine, amitriptyline, atropine, chlorpyrifos, diazepam, fenitrothion, haloperidol, lidocaine, malathion, mianserin, nicotine and triazolam significantly inhibited 14 C-TEA uptake; IC 50 values were 59.2, 2.4, 2.0, 20.7, 32.3, 13.2, 32.5, 104.6, 71.1, 17.7, 52.8 and 65.5 μM, respectively. In addition, aconitine, amitriptyline, atropine, chlorpyrifos, fenitrothion, haloperidol, lidocaine, and nicotine displayed competitive inhibition with K i values of 145.6, 2.5, 2.4, 24.8, 16.9, 51.6, 86.8 and 57.7 μM, respectively. These in vitro data support the notion that compounds pertaining to a wide variety of different drug classes have the potential to decrease renal clearance of drugs transported via hOCT2. Consequently, these data warrant additional studies to probe hOCT2 and its role to influence drug pharmacokinetics

  13. Hemodynamic and renal implications of sodium-glucose cotransporter- 2 inhibitors in type 2 diabetes mellitus.

    Science.gov (United States)

    Tejedor Jorge, Alberto

    2016-11-01

    In DM2, there is increased expression of the proximal glucose transporter SGLT2. The increased glucose reabsorption from the urine to the proximal tubule and subsequently to the bloodstream, has three direct effects on the prognosis of patients with DM2: a) it increases the daily glucose load by raising the renal threshold for glucose, thus augmenting requirements for oral antidiabetics and insulin. This progressive increase occurs throughout the course of the disease and in parallel with the increase in renal mass (renal hypertrophy); b) because of the greater glucose reabsorption, glycosuria is lower than the level corresponding to glycaemia, decreasing the stimulus on the tubuloglomerular feedback system of the distal nephron. As a result, the glomerular vasodilation caused by hyperglycaemia is not arrested, maintaining glomerular hyperfiltration, and c) the excess glucose transported to the proximal tubular cells modifies their redox status, increasing local production of glycosylating products and activating local production of proinflammatory and profibrotic proliferative mediators. These mediators are responsible for the direct free radical damage to proximal tubular cells, for increased SGLT2 expression, increased production of collagen IV and extracellular matrix, and activation of monocyte/macrophages able to cause endothelial injury. The use of SGLT2 inhibitors not only reduces the reabsorption of glucose from the glomerular filtrate back into the circulationthus improving metabolic control in diabetesbut also restores tubuloglomerular feedback by increasing glycosuria and distal urinary flow. However, the most notable effect is due to inhibition of glucose entry to the proximal tubular cells. Glycosuria is toxic to the kidney: it harms glucosetransporting cells, that is, the proximal cells, which contain SGLT2. In animal models, SGLT2 inhibition reduces local production of oxygen-free radicals, the formation of mesangial matrix and collagen IV

  14. Choline kinase alpha and hexokinase-2 protein expression in hepatocellular carcinoma: association with survival.

    Directory of Open Access Journals (Sweden)

    Sandi A Kwee

    Full Text Available PURPOSE: Hexokinase-2 (HK2 and more recently choline kinase alpha (CKA expression has been correlated with clinical outcomes in several major cancers. This study examines the protein expression of HK2 and CKA in hepatocellular carcinoma (HCC in association with patient survival and other clinicopathologic parameters. METHODS: Immunohistochemical analysis for HK2 and CKA expression was performed on a tissue microarray of 157 HCC tumor samples. Results were analyzed in relation to clinicopathologic data from Surveillance, Epidemiology, and End-Results Program registries. Mortality rates were assessed by Kaplan-Meier estimates and compared using log-rank tests. Predictors of overall survival were assessed using proportional hazards regression. RESULTS: Immunohistochemical expression of HK2 and CKA was detected in 71 (45% and 55 (35% tumor samples, respectively. Differences in tumor HK2 expression were associated with tumor grade (p = 0.008 and cancer stage (p = 0.001, while CKA expression differed significantly only across cancer stage (p = 0.048. Increased mortality was associated with tumor HK2 expression (p = 0.003 as well as CKA expression (p = 0.03 with hazard ratios of 1.86 (95% confidence interval (CI 1.23-2.83 and 1.59 (95% CI 1.04-2.41, respectively. Similar effects on overall survival were noted in a subset analysis of early stage (I and II HCC. Tumor HK2 expression, but not CKA expression, remained a significant predictor of survival in multivariable analyses. CONCLUSION: HK2 and CKA expression may have biologic and prognostic significance in HCC, with tumor HK2 expression being a potential independent predictor of survival.

  15. The HK2 Dependent "Warburg Effect" and Mitochondrial Oxidative Phosphorylation in Cancer: Targets for Effective Therapy with 3-Bromopyruvate.

    Science.gov (United States)

    Lis, Paweł; Dyląg, Mariusz; Niedźwiecka, Katarzyna; Ko, Young H; Pedersen, Peter L; Goffeau, Andre; Ułaszewski, Stanisław

    2016-12-15

    This review summarizes the current state of knowledge about the metabolism of cancer cells, especially with respect to the "Warburg" and "Crabtree" effects. This work also summarizes two key discoveries, one of which relates to hexokinase-2 (HK2), a major player in both the "Warburg effect" and cancer cell immortalization. The second discovery relates to the finding that cancer cells, unlike normal cells, derive as much as 60% of their ATP from glycolysis via the "Warburg effect", and the remaining 40% is derived from mitochondrial oxidative phosphorylation. Also described are selected anticancer agents which generally act as strong energy blockers inside cancer cells. Among them, much attention has focused on 3-bromopyruvate (3BP). This small alkylating compound targets both the "Warburg effect", i.e., elevated glycolysis even in the presence oxygen, as well as mitochondrial oxidative phosphorylation in cancer cells. Normal cells remain unharmed. 3BP rapidly kills cancer cells growing in tissue culture, eradicates tumors in animals, and prevents metastasis. In addition, properly formulated 3BP shows promise also as an effective anti-liver cancer agent in humans and is effective also toward cancers known as "multiple myeloma". Finally, 3BP has been shown to significantly extend the life of a human patient for which no other options were available. Thus, it can be stated that 3BP is a very promising new anti-cancer agent in the process of undergoing clinical development.

  16. Leucine-rich repeat kinase 2 (LRRK2-deficient rats exhibit renal tubule injury and perturbations in metabolic and immunological homeostasis.

    Directory of Open Access Journals (Sweden)

    Daniel Ness

    Full Text Available Genetic evidence links mutations in the LRRK2 gene with an increased risk of Parkinson's disease, for which no neuroprotective or neurorestorative therapies currently exist. While the role of LRRK2 in normal cellular function has yet to be fully described, evidence suggests involvement with immune and kidney functions. A comparative study of LRRK2-deficient and wild type rats investigated the influence that this gene has on the phenotype of these rats. Significant weight gain in the LRRK2 null rats was observed and was accompanied by significant increases in insulin and insulin-like growth factors. Additionally, LRRK2-deficient rats displayed kidney morphological and histopathological alterations in the renal tubule epithelial cells of all animals assessed. These perturbations in renal morphology were accompanied by significant decreases of lipocalin-2, in both the urine and plasma of knockout animals. Significant alterations in the cellular composition of the spleen between LRRK2 knockout and wild type animals were identified by immunophenotyping and were associated with subtle differences in response to dual infection with rat-adapted influenza virus (RAIV and Streptococcus pneumoniae. Ontological pathway analysis of LRRK2 across metabolic and kidney processes and pathological categories suggested that the thioredoxin network may play a role in perturbing these organ systems. The phenotype of the LRRK2 null rat is suggestive of a complex biology influencing metabolism, immune function and kidney homeostasis. These data need to be extended to better understand the role of the kinase domain or other biological functions of the gene to better inform the development of pharmacological inhibitors.

  17. Could grape seed extract modulate nephritic damage induced by ...

    African Journals Online (AJOL)

    RBCs). Preadministration of GSO to Metho-induced rats revealed apparent normal renal parenchyma. The proximal convoluted tubules and collecting tubules appeared near to normal with their narrow lumen. Preadministration with GSO ...

  18. Effect of a novel bioactive glass-ceramic on dentinal tubule occlusion: an in vitro study.

    Science.gov (United States)

    Zhong, Y; Liu, J; Li, X; Yin, W; He, T; Hu, D; Liao, Y; Yao, X; Wang, Y

    2015-03-01

    This in vitro study aimed to assess the ability and efficacy of HX-BGC, a novel bioactive glass-ceramic (SiO2-P2 O5-CaO-Na2 O-SrO), to reduce dentine tubule permeability. Dentine discs from human third molars were etched and randomly allocated into five groups: Group 1--distilled water; Group 2--Sensodyne Repair toothpaste (containing NovaMin®); Group 3--HX-BGC toothpaste (containing 7.5% HX-BGC); Group 4--control toothpaste (without HX-BGC); and Group 5--HX-BGC powder. Specimens were treated daily by brushing with an electric toothbrush for 20 seconds. Between daily treatments (7 days total), specimens were immersed in artificial saliva for 24 hours. Dentine permeability was measured at baseline, after the first treatment, after the first 24-hour immersion in artificial saliva and at the end of day 7. Dentine morphology and surface deposits were observed by scanning electron microscopy after one day and 7 days of treatment, respectively. Sensodyne Repair and bioactive glass-ceramic toothpaste significantly and immediately lowered dentine permeability. The HX-BGC powder group showed the highest reduction in dentine permeability after 7 days of treatment. The novel bioactive glass-ceramic material HX-BGC is effective in reducing dentine permeability by occluding open dentine tubules, indicating that HX-BGC may be a potential treatment for dentine hypersensitivity. © 2015 Australian Dental Association.

  19. Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods.

    Science.gov (United States)

    Vatkar, Niranjan Ashok; Hegde, Vivek; Sathe, Sucheta

    2016-01-01

    To compare the vitality of Enterococcus faecalis within dentinal tubules after subjected to five root canal disinfection methods. Dentin blocks (n = 60) were colonized with E. faecalis. After 4 weeks of incubation, the dentin blocks were divided into one control and five test groups (n = 10 each). The root canals of test groups were subjected to one of the disinfection methods, namely, normal saline (NS), sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), neodymium-doped yttrium aluminum garnet (Nd: YAG) laser, and diode laser. The effect of disinfection methods was assessed by LIVE/DEAD BacLight stain under the confocal laser scanning microscopy to determine the "zone of dead bacteria" (ZDB). Mean values were calculated for ZDB and the difference between groups was established. Penetration of E. faecalis was seen to a depth of >1000 μm. Viable bacteria were detected with NS irrigation. NaOCl and CHX showed partial ZDB. When the root canals were disinfected with Nd: YAG and diode lasers, no viable bacteria were found. E. faecalis has the ability to colonize inside dentinal tubules to a depth of >1000 μm. In contrast to conventional irrigants, both Nd: YAG and diode lasers were effective in eliminating the vitality of E. faecalis. NS, NaOCl, and CHX showed viable bacteria remaining in dentinal tubules.

  20. Ribavirin exposure induces histopathological changes in the seminiferous tubules of testes in albino rats

    International Nuclear Information System (INIS)

    Batool, A.

    2013-01-01

    Study objectives: The objectives of the study are to describe and compare histopathological changes in the seminiferous tubules of testes of rat, with different doses of Ribavirin at different time intervals. Introduction: The chemical disturbances may affect a vast number of potential sites in male reproductive system as well as its complex hormonal regulation. Testicular toxicity may reduce the fertility of the male. The current study was conducted to evaluate the effects of Ribavirin on the histological structure of seminiferous tubules in the testes of albino rats. Materials and Methods: Seventy two sexually mature adult male albino rats weighing 180-200gms were divided into four groups: A, B, C and D; each group having 18 rats. Ribavirin was administered intraperitoneally in different doses to these groups that were 20mg, 100mg and 200mg/kg body weight, while group A was control. Each group was further divided into three subgroups according to three time points which were selected for sacrifice that were 20th, 40th and 60th day from the last exposure to drug. Six randomly selected rats from each group were sacrificed on every sacrifice time. Results and Conclusion: The seminiferous tubules with degenerative changes like appearance of vacuole and necrotic material were observed in comparison to control groups, on 20th day of sacrifice in all groups. In rats sacrificed on day 40th and 60th, the sign of recovery in the form of regeneration of seminiferous epithelium was observed that was more marked in low dose groups than high dose groups which showed late recovery. We conclude that ribavirin being used as antiviral drug induces reversible degenerative changes in the seminiferous tubules of testes of albino rats. (author)

  1. Polymyxin B causes DNA damage in HK-2 cells and mice.

    Science.gov (United States)

    Yun, B; Zhang, T; Azad, M A K; Wang, J; Nowell, C J; Kalitsis, P; Velkov, T; Hudson, D F; Li, J

    2018-03-20

    Increasing incidence of multidrug-resistant bacteria presents an imminent risk to global health. Polymyxins are 'last-resort' antibiotics against Gram-negative 'superbugs'; however, nephrotoxicity remains a key impediment in their clinical use. Molecular mechanisms underlying this nephrotoxicity remain poorly defined. Here, we examined the pathways which led to polymyxin B induced cell death in vitro and in vivo. Human proximal tubular cells were treated with polymyxin B (12.5-100 μM) for up to 24 h and showed a significant increase in micronuclei frequency, as well as abnormal mitotic events (over 40% in treated cells, p < 0.05). Time-course studies were performed using a mouse nephrotoxicity model (cumulative 72 mg/kg). Kidneys were collected over 48 h and investigated for histopathology and DNA damage. Notable increases in γH2AX foci (indicative of double-stranded breaks) were observed in both cell culture (up to ~ 44% cells with 5+ foci at 24 h, p < 0.05) and mice treated with polymyxin B (up to ~ 25%, p < 0.05). Consistent with these results, in vitro assays showed high binding affinity of polymyxin B to DNA. Together, our results indicate that polymyxin B nephrotoxicity is associated with DNA damage, leading to chromosome missegregation and genome instability. This novel mechanistic information may lead to new strategies to overcome the nephrotoxicity of this important last-line class of antibiotics.

  2. Methomyl is a water-soluble crystalline solid that gives off a ...

    African Journals Online (AJOL)

    NBU

    RBCs). Pre- administration of GSO to Metho-induced rats revealed apparent normal renal parenchyma. The proximal convoluted tubules and collecting tubules appeared near to normal with their narrow lumen. Pre- administration with GSO ...

  3. Tissue-specific amino acid transporter partners ACE2 and collectrin differentially interact with hartnup mutations

    DEFF Research Database (Denmark)

    Camargo, Simone M R; Singer, Dustin; Makrides, Victoria

    2008-01-01

    BACKGROUND & AIMS: Hartnup amino acid transporter B(0)AT1 (SLC6A19) is the major luminal sodium-dependent neutral amino acid transporter of small intestine and kidney proximal tubule. The expression of B(0)AT1 in kidney was recently shown to depend on its association with collectrin (Tmem27...

  4. Early effects of aldosterone on Na-K pump in rat cortical collecting tubules

    International Nuclear Information System (INIS)

    Fujii, Y.; Takemoto, F.; Katz, A.I.

    1990-01-01

    Sustained exposure to aldosterone (Aldo) increases the abundance and activity of the Na-K pump in cortical collecting tubules (CCT). However, the onset and mechanism of the early interaction of Aldo with the CCT pump, especially in adrenal-intact animals, are unclear. We evaluated the short-term effects of the hormone on Na-K-adenosinetriphosphatase (ATPase) activity and on ouabain-sensitive 86Rb uptake, a measure of the transporting rate of the pump, in microdissected CCT from adrenal-intact rats. Incubation with Aldo (10(-8) M, 2 h) had no effect on Na-K-ATPase activity (Vmax), whereas it produced at least a twofold increase in 86Rb uptake. This effect was generated by physiological concentrations of the hormone (threshold 10(-10) M; apparent K1/2 approximately 10(-9) M), after a short lag of less than or equal to 30 min. Incubation with Aldo in the presence of amiloride or nystatin or in a Na-free medium (choline chloride) did not prevent the enhanced 86Rb uptake seen after Aldo alone; possible interpretations of these observations are discussed. We conclude that Aldo produces a rapid stimulation of pump function in CCT that precedes its induction of new pump synthesis; the physiological significance of this effect is suggested by its occurrence in tubules from adrenal-intact animals within the time frame and concentration range of the hormone's effects on electrolyte transport

  5. Na(+)-D-glucose cotransporter in the kidney of Squalus acanthias: molecular identification and intrarenal distribution.

    Science.gov (United States)

    Althoff, Thorsten; Hentschel, Hartmut; Luig, Jutta; Schütz, Hendrike; Kasch, Myriam; Kinne, Rolf K-H

    2006-04-01

    Using primers against conserved regions of mammalian Na(+)-d-glucose cotransporters (SGLT), a cDNA was cloned from the kidney of spiny dogfish shark (Squalus acanthias). On the basis of comparison of amino acid sequence, membrane topology, and putative glycosylation and phosphorylation sites, the cDNA could be shown to belong to the family of sglt genes. Indeed, Na(+)-dependent d-glucose uptake could be demonstrated after expression of the gene in Xenopus laevis oocytes. In a dendrogram, the SGLT from shark kidney has a high homology to the mammalian SGLT2. Computer analysis revealed that the elasmobranch protein is most similar to the mammalian proteins in the transmembrane regions and contains already all the amino acids identified to be functionally important, suggesting early conservation during evolution. Extramembraneous loops show larger variations. This holds especially for loop 13, which has been implied as a phlorizin-binding domain. Antibodies were generated and the intrarenal distribution of the SGLT was studied in cryosections. In parallel, the nephron segments were identified by lectins. Positive immunoreactions were found in the proximal tubule in the early parts PIa and PIb and the late segment PIIb. The large PIIa segment of the proximal tubule showed no reaction. In contrast to the mammalian kidney also the late distal tubule, the collecting tubule, and the collecting duct showed immunoreactivity. The molecular information confirms previous vesicle studies in which a low affinity SGLT with a low stoichiometry has been observed and supports the notion of a similarity of the shark kidney SGLT to the mammalian SGLT2. Despite its presence in the late parts of the nephron, the absence of SGLT in the major part of the proximal tubule, the relatively low affinity, and in particular the low stoichiometry might explain the lack of a T(m) for d-glucose in the shark kidney.

  6. PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun [Department of Surgery, The Children' s Hospital of Xuzhou, Xuzhou, Jiangsu Province 221006 (China); Wang, Rong, E-mail: wangrong2008163@163.com [Department of Ultrasonography, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province 221006 (China)

    2015-08-21

    Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2.

  7. Early results for treatment of two- and three-part fractures of the proximal humerus using Contours PHP (proximal humeral plate).

    Science.gov (United States)

    Biazzo, Alessio; Cardile, Carlo; Brunelli, Luca; Ragni, Paolo; Clementi, Daniele

    2017-04-28

    The management of displaced 2- and 3-part fractures of the proximal humerus is controversial, both in younger and in elderly patients. The purpose of this paper is to evaluate the functional results of the Contours Proximal Humerus Plate (OrthofixR, Bussolengo,Verona, Italy), for the treatment of displaced 2- and 3-part fractures of the proximal humerus. We retrospectively reviewed 55 patients with proximal humerus fractures, who underwent osteosynthesis with Contours Proximal Humerus Plate from December 2011 to March 2015. We had 21 patients with 2-part fractures and with an average age of 67.1 years and 34 patients with 3-part fractures, with average age of 63.6 years. The average union time was 3 months. The mean Constant score was 67 for 2-part fracture group and 64.9 for 3-part fracture group. The difference was not statistically significant (p = 0.18). The overall complication rate was 14.5 %. Six patients underwent additional surgery (10.9%). The most frequent major complication was secondary loss of reduction following varus collapse of the fracture (2 cases). In these patients, there was loss of medial hinge integrity due to impaction and osteoporosis. The placement of the main locking screw in the calcar area to provide inferomedial support is the rational of the Contours Proximal Humerus Plate. Osteosynthesis with Contours Proximal Humerus Plate is a safe system for treating displaced 2- and 3-part fractures of the proximal humerus, with good functional results and complication rates comparable to those reported in the literature.

  8. The HK2 Dependent “Warburg Effect” and Mitochondrial Oxidative Phosphorylation in Cancer: Targets for Effective Therapy with 3-Bromopyruvate

    Directory of Open Access Journals (Sweden)

    Paweł Lis

    2016-12-01

    Full Text Available This review summarizes the current state of knowledge about the metabolism of cancer cells, especially with respect to the “Warburg” and “Crabtree” effects. This work also summarizes two key discoveries, one of which relates to hexokinase-2 (HK2, a major player in both the “Warburg effect” and cancer cell immortalization. The second discovery relates to the finding that cancer cells, unlike normal cells, derive as much as 60% of their ATP from glycolysis via the “Warburg effect”, and the remaining 40% is derived from mitochondrial oxidative phosphorylation. Also described are selected anticancer agents which generally act as strong energy blockers inside cancer cells. Among them, much attention has focused on 3-bromopyruvate (3BP. This small alkylating compound targets both the “Warburg effect”, i.e., elevated glycolysis even in the presence oxygen, as well as mitochondrial oxidative phosphorylation in cancer cells. Normal cells remain unharmed. 3BP rapidly kills cancer cells growing in tissue culture, eradicates tumors in animals, and prevents metastasis. In addition, properly formulated 3BP shows promise also as an effective anti-liver cancer agent in humans and is effective also toward cancers known as “multiple myeloma”. Finally, 3BP has been shown to significantly extend the life of a human patient for which no other options were available. Thus, it can be stated that 3BP is a very promising new anti-cancer agent in the process of undergoing clinical development.

  9. The role of the kidney in lipid metabolism

    DEFF Research Database (Denmark)

    Moestrup, Søren K; Nielsen, Lars Bo

    2005-01-01

    PURPOSE OF REVIEW: Cellular uptake of plasma lipids is to a large extent mediated by specific membrane-associated proteins that recognize lipid-protein complexes. In the kidney, the apical surface of proximal tubules has a high capacity for receptor-mediated uptake of filtered lipid-binding plasma...... proteins. We describe the renal receptor system and its role in lipid metabolism in health and disease, and discuss the general effect of the diseased kidney on lipid metabolism. RECENT FINDINGS: Megalin and cubilin are receptors in the proximal tubules. An accumulating number of lipid......-binding and regulating proteins (e.g. albumin, apolipoprotein A-I and leptin) have been identified as ligands, suggesting that their receptors may directly take up lipids in the proximal tubules and indirectly affect plasma and tissue lipid metabolism. Recently, the amnionless protein was shown to be essential...

  10. Influence of extracellular HCO3- and pH on lysine (LYS) and leucine (LEU) uptake and metabolism in swine renal tubules

    International Nuclear Information System (INIS)

    Patience, J.F.; Esteve-Garcia, E.; Austic, R.E.

    1986-01-01

    Fragments of renal tubules prepared by collagenase treatment of renal cortex were suspended to Krebs-Henseleit buffers which were modified to contain 10, 25 and 35 mM HCO 3 - at pH 7.4, or 25 mM HCO 3 - at pH 7.1, 7.4 and 7.7. Buffers were oxygenated with O 2 -CO 2 gas mixtures varying in carbon dioxide concentration prior to incubation. Approximately 100 mg tubules were incubated with shaking at 37 0 C for 30 min in serum-stoppered 25 ml Erlenmeyer flasks in 3.0 ml of buffer containing 0.1% dialyzed bovine serum albumin, 5 mM D-glucose and 0.3 mM L-[U- 14 C]-lysine or L-[1- 14 C]-leucine. The incorporation of carbon-14 into CO 2 and into 10% sulfosalicylic acid (SSA)-soluble and SSA-insoluble fractions of the incubation mixture was determined. Low (10mM) bicarbonate reduced the incorporation of lys and leu into protein but did not substantially affect the recovery of 14 CO 2 from either amino acid. High pH (7.7) resulted in reduced incorporation of lys and leu into protein, and decreased the oxidation of lys but not leu. The specific activity of lys (leu was not determined) in the SSA-soluble fraction was unaffected by bicarbonate or pH. The authors conclude that variations in extracellular pH and HCO 3 - (or pCO 2 ) affect the metabolism of amino acids by renal tubules and that low extracellular HCO 3 - (or pCO 2 ) may depress the incorporation of amino acids into protein

  11. Immortalization of canine adipose-derived mesenchymal stem cells and their seminiferous tubule transplantation.

    Science.gov (United States)

    Fang, Jia; Wei, Yudong; Teng, Xin; Zhao, Shanting; Hua, Jinlian

    2018-04-01

    Adipose-derived mesenchymal stem cells (ADSCs) are proven to provide good effects in numerous tissue engineering application and other cell-based therapies. However, the difficulty in the proliferation of ADSCs, known as the "Hayflick limit" in vitro, limits their clinical application. Here, we immortalized canine ADSCs (cADSCs) with SV40 gene and transplanted them into busulfan-induced seminiferous tubules of infertile mice. The proliferation of these immortalized cells was improved significantly. Then, cellular differentiation assays showed that the immortalized cADSCs could differentiate into three-germ-layer cells, osteogenesis, chondrogenesis, adipogenesis phenotypes, and primordial germ cell-like cells (PGCLCs). In addition, the immortalized cADSCs can proliferate in the busulfan-induced seminiferous tubules of infertile mice. These findings confirmed that the immortalized cADSCs maintain the criteria of cADSCs. © 2017 Wiley Periodicals, Inc.

  12. Proximity-induced spin-valley polarization in silicene or germanene on F-doped WS2

    KAUST Repository

    Sattar, Shahid

    2016-11-11

    Silicene and germanene are key materials for the field of valleytronics. However, interaction with the substrate, which is necessary to support the electronically active medium, becomes a major obstacle. In the present work, we propose a substrate (F-doped WS2) that avoids detrimental effects and at the same time induces the required valley polarization, so that no further steps are needed for this purpose. The behavior is explained by proximity effects on silicene or germanene, as demonstrated by first-principles calculations. Broken inversion symmetry due to the presence of WS2 opens a substantial band gap in silicene or germanene. F doping of WS2 results in spin polarization, which, in conjunction with proximity-enhanced spin-orbit coupling, creates sizable spin-valley polarization.

  13. Shape transitions in anisotropic multicomponent lipid tubules

    Directory of Open Access Journals (Sweden)

    Tim eAtherton

    2016-05-01

    Full Text Available Abstract Ternary mixtures of saturated and unsaturated lipids together with cholesterol can be induced to phase separate by photo-peroxidation into lipid-ordered Lo and lipid-disordered Ld domains. Because these have different mechanical properties, the phase separation is accompanied by dramatic changes in morphology. This work considers a tubule composed of Ld phase with Lo phase inclusions that possess greater rigidity; this system has been shown experimentally by Yuan and coworkers to spontaneously adopt either banded or disc configurations following phase separation. The static behaviour of inter-domain interactions is analyzed in each of these geometries by solving the linearized shape equations. These calculations suggest a possible mechanism by which the two structures form.

  14. Microinjection studies of phosphate permeability in rats during mild saline diuresis: influence of acute thyroparathyroidectomy and parathormone administration

    International Nuclear Information System (INIS)

    Poujeol, P.; Rouffignac, C. de.

    1975-01-01

    The tubular permeability to phosphate of the different segments of the rat nephron and the influence of parathyroid hormone on such a permeability were investigated. Tracer microinjections of 32 P and 3 H inulin were performed in control, acutely thyroparathyroidectomized (TPTX) and TPTX + PTH animals undergoing saline diuresis. In order to estimate the 32 P reabsorption capacity of the proximal convoluted tubule (PCT), the loop of Henle and the terminal part of the nephron, microinjections were performed in early proximal, late proximal and early distal tubules respectively. The results reported confirm that the renal phosphate reabsorption is under PTH control [fr

  15. In-Solution SH2 Domain Binding Assay Based on Proximity Ligation.

    Science.gov (United States)

    Machida, Kazuya

    2017-01-01

    Protein-protein interactions mediated by SH2 domains confer specificity in tyrosine kinase pathways. Traditional assays for assessing interactions between an SH2 domain and its interacting protein such as far-Western and pull-down are inherently low throughput. We developed SH2-PLA, an in-solution SH2 domain binding assay, that takes advantage of the speed and sensitivity of proximity ligation and real-time PCR. SH2-PLA allows for rapid assessment of SH2 domain binding to a target protein using only a few microliters of cell lysate, thereby making it an attractive new tool to study tyrosine kinase signaling.

  16. Fabrication and characterization of dendrimer-functionalized nano-hydroxyapatite and its application in dentin tubule occlusion.

    Science.gov (United States)

    Lin, Xuandong; Xie, Fangfang; Ma, Xueling; Hao, Yuhong; Qin, Hejia; Long, Jindong

    2017-06-01

    The occlusion of dentinal tubules is an effective method to alleviate the symptoms of dentin hypersensitivity. In this paper, we successfully modified nano-hydroxyapatite (n-HAP) with carboxyl-terminated polyamidoamine dendrimers by an aqueous-based chemical method and verified by fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM). Then the demineralization dentin discs were randomly divided into 4 groups, corresponding to subsequent brushing experiments: deionized water and kept in artificial saliva (AS), dendrimer-functionalized n-HAP and stored in AS, n-HAP and saved in AS, dendrimer-functionalized n-HAP and stored in deionized water. After 7 days of simulated brushing, dentin discs followed the in vitro characterization using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy and microhardness test. These data suggested that dendrimer-functionalized n-HAP could crosslink with collagen fibers and resulted in effective dentinal tubule occlusion. Moreover, the new material can induce the HAP formation with the help of superficial carboxyl and fill the spaces in dentinal tubules furtherly. The microhardness of dendrimer-functionalized n-HAP-treated specimens was significantly higher than others. In summary, dendrimer-functionalized n-HAP can be a new therapeutic material for the treatment of dentin hypersensitivity.

  17. The pelvic kidney of male Ambystoma maculatum (Amphibia, urodela, ambystomatidae) with special reference to the sexual collecting ducts.

    Science.gov (United States)

    Siegel, Dustin S; Sever, David M; Aldridge, Robert D

    2010-12-01

    This study details the gross and microscopic anatomy of the pelvic kidney in male Ambystoma maculatum. The nephron of male Ambystoma maculatum is divided into six distinct regions leading sequentially away from a renal corpuscle: (1) neck segment, which communicates with the coelomic cavity via a ventrally positioned pleuroperitoneal funnel, (2) proximal tubule, (3) intermediate segment, (4) distal tubule, (5) collecting tubule, and (6) collecting duct. The proximal tubule is divided into a vacuolated proximal region and a distal lysosomic region. The basal plasma membrane is modified into intertwining microvillus lamellae. The epithelium of the distal tubule varies little along its length and is demarcated by columns of mitochondria with their long axes oriented perpendicular to the basal lamina. The distal tubule possesses highly interdigitating microvillus lamellae from the lateral membranes and pronounced foot processes of the basal membrane that are not intertwined, but perpendicular to the basal lamina. The collecting tubule is lined by an epithelium with dark and light cells. Light cells are similar to those observed in the distal tuble except with less mitochondria and microvillus lamellae of the lateral and basal plasma membrane. Dark cells possess dark euchromatic nuclei and are filled with numerous small mitochondria. The epithelium of the neck segment, pleuroperitoneal funnel, and intermediate segment is composed entirely of ciliated cells with cilia protruding from only the central portion of the apical plasma membrane. The collecting duct is lined by a highly secretory epithelium that produces numerous membrane bound granules that stain positively for neutral carbohydrates and proteins. Apically positioned ciliated cells are intercalated between secretory cells. The collecting ducts anastomose caudally and unite with the Wolffian duct via a common collecting duct. The Wolffian duct is secretory, but not to the extent of the collecting duct

  18. Detection of Fusobacterium nucleatum in two cases of empyema and lung abscess using paromomycin-vancomycin supplemented Brucella HK agar.

    Science.gov (United States)

    Nagaoka, Kentaro; Yanagihara, Katsunori; Morinaga, Yoshitomo; Kohno, Shigeru

    2017-02-01

    Fusobacterium nucleatum was found in patients with empyema or pulmonary abscess, using paromomycin-vancomycin Brucella HK agar. In vitro examination revealed that growth of the strains differed significantly in different media. Clinicians should be aware that suboptimal F. nucleatum cultivation methods may result in an underestimation of its frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. INPP4B-mediated tumor resistance is associated with modulation of glucose metabolism via hexokinase 2 regulation in laryngeal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Min, Joong Won [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Kwang Il [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Hyun-Ah; Kim, Eun-Kyu; Noh, Woo Chul [Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeon, Hong Bae [Biomedical Research Institute, MEDIPOST Co., Ltd., Seoul (Korea, Republic of); Cho, Dong-Hyung [Graduate School of East-West Medical Science, Kyung Hee University, Gyeonggi-do (Korea, Republic of); Oh, Jeong Su [Department of Genetic Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Park, In-Chul; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kim, Jae-Sung, E-mail: jaesung@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2013-10-11

    Highlights: •HIF-1α-regulated INPP4B enhances glycolysis. •INPP4B regulates aerobic glycolysis by inducing HK2 via Akt-mTOR pathway. •Blockage of INPP4B and HK2 sensitizes radioresistant laryngeal cancer cells to radiation and anticancer drug. •INPP4B is associated with HK2 in human laryngeal cancer tissues. -- Abstract: Inositol polyphosphate 4-phosphatase type II (INPP4B) was recently identified as a tumor resistance factor in laryngeal cancer cells. Herein, we show that INPP4B-mediated resistance is associated with increased glycolytic phenotype. INPP4B expression was induced by hypoxia and irradiation. Intriguingly, overexpression of INPP4B enhanced aerobic glycolysis. Of the glycolysis-regulatory genes, hexokinase 2 (HK2) was mainly regulated by INPP4B and this regulation was mediated through the Akt-mTOR pathway. Notably, codepletion of INPP4B and HK2 markedly sensitized radioresistant laryngeal cancer cells to irradiation or anticancer drug. Moreover, INPP4B was significantly associated with HK2 in human laryngeal cancer tissues. Therefore, these results suggest that INPP4B modulates aerobic glycolysis via HK2 regulation in radioresistant laryngeal cancer cells.

  20. Transport of Streptococcus pneumoniae capsular polysaccharide in MHC Class II tubules.

    Directory of Open Access Journals (Sweden)

    Tom Li Stephen

    2007-03-01

    Full Text Available Bacterial capsular polysaccharides are virulence factors and are considered T cell-independent antigens. However, the capsular polysaccharide Sp1 from Streptococcus pneumoniae serotype 1 has been shown to activate CD4(+ T cells in a major histocompatibility complex (MHC class II-dependent manner. The mechanism of carbohydrate presentation to CD4(+ T cells is unknown. We show in live murine dendritic cells (DCs that Sp1 translocates from lysosomal compartments to the plasma membrane in MHCII-positive tubules. Sp1 cell surface presentation results in reduction of self-peptide presentation without alteration of the MHCII self peptide repertoire. In DM-deficient mice, retrograde transport of Sp1/MHCII complexes resulting in T cell-dependent immune responses to the polysaccharide in vitro and in vivo is significantly reduced. The results demonstrate the capacity of a bacterial capsular polysaccharide antigen to use DC tubules as a vehicle for its transport as an MHCII/saccharide complex to the cell surface for the induction of T cell activation. Furthermore, retrograde transport requires the functional role of DM in self peptide-carbohydrate exchange. These observations open new opportunities for the design of vaccines against microbial encapsulated pathogens.

  1. [Anatomy, physiology and clinical relevance of the connecting tubule].

    Science.gov (United States)

    Miranda, N; Simeoni, M A; Ciriana, E; Panico, C; Cappello, E; Capasso, G B

    2009-01-01

    The cortical distal nephron is the site of fine regulation of salt and water excretion by peptide and mineralocorticoid hormones and the site for specific actions of diuretics. Some data suggest that sodium reabsorption and potassium secretion in the distal convoluted tubule and the connecting tubule (CNT) are sufficient to maintain the sodium and potassium balance, with little or no contribution of the collecting duct. The homeostatic role of the sodium and potassium transport systems in the collecting duct can be questioned, especially in conditions where dietary sodium intake is high and potassium intake is low compared with the physiological needs of the organism. The functional expression of epithelial sodium channels (ENaC) in the CNT is sufficient for furosemide-stimulated urinary acidification and identifies the CNT as a major segment in electrogenic urinary acidification. In the outer renal cortex, the CNT returns to the glomerular hilus and contacts the renal afferent arterioles (Af-Art). This morphology is compatible with a cross-talk between the CNT and Af-Art. This novel regulatory mechanism of the renal microcirculation may participate in the vasodilatation observed during high salt intake, perhaps by antagonizing tubuloglomerular feedback. In conclusion, the cortical distal nephron appears to be a complex site for several physiological mechanisms; it is mainly involved in salt and fluid homeostasis and in acid-base balance maintenance. Furthermore, the CNT segment appears to promote a CNT-Af-Art feedback loop.

  2. Poor prognosis of hexokinase 2 overexpression in solid tumors of digestive system: a meta-analysis.

    Science.gov (United States)

    Wu, Jiayuan; Hu, Liren; Wu, Fenping; Zou, Lei; He, Taiping

    2017-05-09

    Several previous studies have reported the prognostic value of hexokinase 2 (HK2) in digestive system tumors. However, these studies were limited by the small sample sizes and the results were inconsistent among them. Therefore, we conducted a meta-analysis based on 15 studies with 1932 patients to assess the relationship between HK2 overexpression and overall survival (OS) of digestive system malignancies. The relationship of HK2 and clinicopathological features was also evaluated. Hazard ratio (HR) or odds ratio (OR) with its 95% confidence intervals (CI) were calculated to estimate the effect size. Positive HK2 expression showed poor OS in all tumor types (HR = 1.75 [1.41-2.18], P digestive system cancers.

  3. BAG3 directly stabilizes Hexokinase 2 mRNA and promotes aerobic glycolysis in pancreatic cancer cells.

    Science.gov (United States)

    An, Ming-Xin; Li, Si; Yao, Han-Bing; Li, Chao; Wang, Jia-Mei; Sun, Jia; Li, Xin-Yu; Meng, Xiao-Na; Wang, Hua-Qin

    2017-12-04

    Aerobic glycolysis, a phenomenon known historically as the Warburg effect, is one of the hallmarks of cancer cells. In this study, we characterized the role of BAG3 in aerobic glycolysis of pancreatic ductal adenocarcinoma (PDAC) and its molecular mechanisms. Our data show that aberrant expression of BAG3 significantly contributes to the reprogramming of glucose metabolism in PDAC cells. Mechanistically, BAG3 increased Hexokinase 2 (HK2) expression, the first key enzyme involved in glycolysis, at the posttranscriptional level. BAG3 interacted with HK2 mRNA, and the degree of BAG3 expression altered recruitment of the RNA-binding proteins Roquin and IMP3 to the HK2 mRNA. BAG3 knockdown destabilized HK2 mRNA via promotion of Roquin recruitment, whereas BAG3 overexpression stabilized HK2 mRNA via promotion of IMP3 recruitment. Collectively, our results show that BAG3 promotes reprogramming of glucose metabolism via interaction with HK2 mRNA in PDAC cells, suggesting that BAG3 may be a potential target in the aerobic glycolysis pathway for developing novel anticancer agents. © 2017 An et al.

  4. Role of IGFBP7 in Diabetic Nephropathy: TGF-β1 Induces IGFBP7 via Smad2/4 in Human Renal Proximal Tubular Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Jun Watanabe

    Full Text Available Tubular injury is one of the important determinants of progressive renal failure in diabetic nephropathy (DN, and TGF-β1 has been implicated in the pathogenesis of tubulointerstitial disease that characterizes proteinuric renal disease. The aim of this study was to identify novel therapeutic target molecules that play a role in the tubule damage of DN. We used an LC-MS/MS-based proteomic technique and human renal proximal epithelial cells (HRPTECs. Urine samples from Japanese patients with type 2 diabetes (n = 46 were used to quantify the candidate protein. Several proteins in HRPTECs in cultured media were observed to be driven by TGF-β1, one of which was 33-kDa IGFBP7, which is a member of IGFBP family. TGF-β1 up-regulated the expressions of IGFBP7 mRNA and protein in a dose- and time-dependent fashion via Smad2 and 4, but not MAPK pathways in HRPTECs. In addition, the knockdown of IGFBP7 restored the TGF-β1-induced epithelial to mesenchymal transition (EMT. In the immunohistochemical analysis, IGFBP7 was localized to the cytoplasm of tubular cells but not that of glomerular cells in diabetic kidney. Urinary IGFBP7 levels were significantly higher in the patients with macroalbuminuria and were correlated with age (r = 0.308, p = 0.037, eGFR (r = -0.376, p = 0.01, urinary β2-microglobulin (r = 0.385, p = 0.008, and urinary N-acetyl-beta-D-glucosaminidase (NAG (r = 0.502, p = 0.000. A multivariate regression analysis identified urinary NAG and age as determinants associated with urinary IGFBP7 levels. In conclusion, our data suggest that TGF-β1 enhances IGFBP7 via Smad2/4 pathways, and that IGFBP7 might be involved in the TGF-β1-induced tubular injury in DN.

  5. In vivo clonal analysis reveals lineage-restricted progenitor characteristics in mammalian kidney development, maintenance, and regeneration

    NARCIS (Netherlands)

    Rinkevich, Y.; Montoro, D.T.; Contreras-Trujillo, H.; Harari-Steinberg, O.; Newman, A.M.; Tsai, J.M.; Lim, X.; van Amerongen, R.; Bowman, A.; Januszyk, M.; Pleniceanu, O.; Nusse, R.; Longaker, M.T.; Weissman, I.L.; Dekel, B.

    2014-01-01

    The mechanism and magnitude by which the mammalian kidney generates and maintains its proximal tubules, distal tubules, and collecting ducts remain controversial. Here, we use long-term in vivo genetic lineage tracing and clonal analysis of individual cells from kidneys undergoing development,

  6. Comparative proteomic analysis of kidney distal convoluted tubule and cortical collecting duct cells following long-term hormonal stimulation

    DEFF Research Database (Denmark)

    Wu, Qi; Moller, Hanne; Rosenbaek, Lena Lindtoft

    2017-01-01

    The distal convoluted tubule (DCT) and the cortical collecting ducts (CCD) are portions of renal tubule that are partly responsible for maintaining the systemic concentrations of potassium, sodium, calcium and magnesium. Despite being structurally similar, DCT and CCD cells have different transpo...... FDR threshold in one cell type plus the unique proteins in this cell type. These 1025 mpkDCT specific proteins and 1211 mpkCCD specific proteins under the three conditions were subjected to further bioinformatics analyses including Panther and DAVID gene ontology analyses, E3 ligase...

  7. [Contribution of the kidney to glucose homeostasis].

    Science.gov (United States)

    Segura, Julián; Ruilope, Luis Miguel

    2013-09-01

    The kidney is involved in glucose homeostasis through three major mechanisms: renal gluconeogenesis, renal glucose consumption, and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most important physiological functions of the kidney, allowing full recovery of filtered glucose, elimination of glucose from the urine, and prevention of calorie loss. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where glucose transporter-2 (GLUT2) and sodium-glucose transporter-2 (SGLT2) are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycemia, the kidney continues to reabsorb glucose, thus maintaining hyperglycemia. Most of the renal glucose reabsorption is mediated by SGLT2. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  8. Proximal Pole Scaphoid Nonunion Reconstruction With 1,2 Intercompartmental Supraretinacular Artery Vascularized Graft and Compression Screw Fixation.

    Science.gov (United States)

    Morris, Mark S; Zhu, Andy F; Ozer, Kagan; Lawton, Jeffrey N

    2018-02-06

    To review the incidence of union of patients with proximal pole scaphoid fracture nonunions treated using a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized graft and a small compression screw. This is a retrospective case series of 12 patients. Calculations of the size of the proximal pole fragment relative to the total scaphoid were performed using posteroanterior view scaphoid radiographs with the wrist in ulnar deviation and flat on the cassette. Analyses were repeated 3 times per subject, and the average ratio of proximal pole fragment relative to the entire scaphoid was calculated. We reviewed medical records, radiographs, and computed tomography (CT) scans of these 12 patients. The CT scans that were performed after an average of 12 weeks were ultimately used to confirm union of the scaphoid fractures. One patient was unable to have a CT so was excluded from the final calculation. All 11 (100%) scaphoid fractures that were assessed by CT were found to be healed at the 12-week assessment point. The mean proximal pole fragment size was 18% (range, 7%-27%) of the entire scaphoid. The 1,2 ICSRA vascularized graft and compression screw was an effective treatment for patients with proximal pole scaphoid fractures. Therapeutic IV. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. The normal development of proximal humeral epiphyseal ossification center in the first 2 years of life

    International Nuclear Information System (INIS)

    Kim, Seung Cheol

    1998-01-01

    The purpose of this study is to ascertain the normal maturation of proximal epiphyseal ossification centers by monthly age during the first years of life. The distribution of age was 0 to 24 months. Six hundred and seventy-five infants were male and 436 were female; their ages were measured in months, and there was no evidence of developmental problems. Proximal humeral epiphyseal ossification centers were evaluated from chest radiographs ; if not visualized, they were graded as 0, and otherwise, as follows : grade 1 : visualized with poor margin or a diameter of less than 1/4 of metaphyseal width; grade 2: visualized with good margin or a diameter of more than 1/4 of metaphyseal width; in grade 3 and 4, two ossification centers were visualized. Grade 3 indicated that one ossification center had the morphology of grade 2. Grade 5 indicated that two ossification centers were fused. We then assessed the relationship between the development of an ossification center and monthly age. A proximal humeral epiphyseal ossification center shows regular maturational features according to monthly age. 6 refs., 2 tabs., 5 figs

  10. Efficacy of Modified Bioactive Glass for Dentin Remineralization and Obstruction of Dentinal Tubules

    Directory of Open Access Journals (Sweden)

    Mahshid Saffarpour

    2017-10-01

    Full Text Available Objectives: This study assessed the efficacy of modified bioactive glass (MBG for dentin remineralization and obstruction of dentinal tubules.Materials and Methods: Thirty-six dentin discs were made from 20 third molars and were stored in 12% lactic acid solution for two weeks to induce demineralization. The samples were divided into three groups (n=12: 1- BG, 2- BG modified with 5% strontium (Sr and 3- BG modified with 10% Sr. After applying the BG, the samples were stored in artificial saliva for 7, 14 and 21 days. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR, X-ray Diffraction (XRD analysis, Scanning Electron Microscopy (SEM, and Energy-Dispersive X-ray (EDX analysis were used to assess remineralization. Also, 6 dentin discs were divided into three groups of BG, BG modified with 5% Sr and BG modified with 10% Sr, to examine tubular occlusion. The discs were etched using 0.5M of EDTA for two minutes and were stored in artificial saliva for 7 days. Changes in dentin surface morphology were evaluated under SEM.Results: Group 3 showed high rates of remineralization at days 7 and 14, although the rate decreased at day 21. Group 2 exhibited high rates of remineralization at days 7, 14 and 21. Dentinal tubules were partially occluded by BG and BG modified with 5% Sr, while they were almost completely obstructed after the use of BG modified with 10% Sr.Conclusions: Strontium increases remineralization. Addition of 10% Sr to BG enhances apatite formation; however, the apatite dissolves over time. Addition of 5% Sr to BG stabilizes the apatite lattice and increases the remineralization.

  11. Hexokinase 2 drives glycogen accumulation in equine endometrium at day 12 of diestrus and pregnancy.

    Science.gov (United States)

    Bramer, Sarah A; Macedo, Alysson; Klein, Claudia

    2017-01-05

    Secretion of histotroph during the prolonged pre-implantation phase in mares is crucial to pregnancy maintenance, manifested as increased embryonic loss in mares with age-related endometrial degeneration. Glycogen content of uterine histotroph is higher during the progesterone-dominated phase of the estrous cycle in mares, but regulatory mechanisms are not well understood. mRNA expression of glycogen-metabolizing enzymes (HK1, HK2, GSK3B, GYS1, PEPCK, PKM, PYGM) in endometrial samples were compared among mares in anestrus, estrus, and at Day 12 of diestrus and pregnancy. In addition, hexokinase 2 (HK2) activity was assessed using a colorimetric assay. HK2 was the key regulator of glycogen accumulation during diestrus and pregnancy; hexokinase transcript abundance and enzyme activity were significantly higher during diestrus and pregnancy than estrus and anestrus. In addition, despite similar relative transcript abundance, hexokinase activity was significantly greater in the pregnant versus diestrous endometrium. Therefore, we inferred there was regulation of hexokinase activity through phosphorylation, in addition to its regulation at the transcriptional level during early pregnancy. Based on immunohistochemistry, HK2 was localized primarily in luminal and glandular epithelial cells, with weaker staining in stromal cells. Among glycogen metabolizing enzymes identified, expression of HK2 was significantly greater during the progesterone-dominated phase of the cycle.

  12. miR-4458 suppresses glycolysis and lactate production by directly targeting hexokinase2 in colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yaguang; Cheng, Chuanyao; Lu, Hong, E-mail: honglu6512@163.com; Wang, Yaqiu

    2016-01-01

    miR-4458, a new tumor-suppressor, was reported to down-regulated in human hepatocellular carcinoma. The expression status, roles and inhibitory mechanisms of miR-4458 in other tumors still need to be clarified. The aim of this study is to investigate the effects of miR-4458 and to elucidate the potential mechanism in colon cancer cells. Using bioinformatic databases, we predicted that hexokinase2 (HK2), a rate-limiting enzyme in the glycolytic pathway, was a target of miR-4458, so the effects of miR-4458 on glycolysis and lactate production was assessed in colon cancer cells. We found that miR-4458 was down-regulated and HK2 was up-regulated in colon cancer cells. Overexpression of miR-4458 inhibited proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. Luciferase activity assays showed that HK2 was a direct target of miR-4458. Moreover, knockdown of HK2 by specific RNAi also suppressed proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. In conclusion, our findings suggested that miR-4458 inhibited the progression of colon cancer cells by inhibition of glycolysis and lactate production via directly targeting HK2 mRNA. - Highlights: • miR-4458 is down-regulated in colon cancer cells. • miR-4458 suppresses proliferation, glycolysis, and lactate production. • HK2 is a target of miR-4458. • HK2 knockdown inhibits proliferation, glycolysis, and lactate production.

  13. influence of crude extract of root of telfairia occidentalis (fluted ...

    African Journals Online (AJOL)

    DJFLEX

    Histologically, the architecture of the kidneys in the experimental animals treated with pumpkin root extract orally and intraperitoneally showed enlarged tubules, distorted glomeruli and Bowman's capsule, shrinking of proximal and distal convoluted tubules compared with the control. These results suggest that the root of ...

  14. Methods to Evaluate the Effect of Ethanol on the Folate Analogue: Fluorescein Methotrexate Uptake in Human Proximal Tubular Cells

    Directory of Open Access Journals (Sweden)

    Sivakumar JT Gowder

    2009-01-01

    Full Text Available Ethanol-induced folate deficiency is due to effects of ethanol on folate metabolism and absorption. We have already shown by using different methods that ethanol interferes with reabsorption of folate from the proximal tubule. In this study, we have used the folate analogue, the fluorescein methotrexate (FL-MTX, in order to evaluate effects of ethanol on FL-MTX uptake by the human proximal tubular (HPT cells by using a confocal microscope and fluoroskan microplate reader. Since endothelins (ETs play a major role in a number of diseases and also in the damage induced by a variety of chemicals, we have used endothelin-B (ET-B and protein kinase-C (PKC inhibitors to evaluate the role of endothelin in ethanol-mediated FL-MTX uptake by using fluoroskan microplate reader. Confocal microscope and fluoroskan studies reveal that cellular absorption of FL-MTX is concentration-dependent. Moreover, ethanol concentration has an impact on FL-MTX uptake. Fluoroskan studies reveal that the ethanol-induced decrease in FL-MTX uptake is reversed by adding the ET-B receptor antagonist (RES-701-1 or PKC-selective inhibitor (BIM. Thus, we can conclude that ethanol may act via ET and ET in turn may act via ET-B receptor and the PKC signaling pathway to impair FL-MTX transport.

  15. Proximal Humerus

    NARCIS (Netherlands)

    Diercks, Ron L.; Bain, Gregory; Itoi, Eiji; Di Giacomo, Giovanni; Sugaya, Hiroyuki

    2015-01-01

    This chapter describes the bony structures of the proximal humerus. The proximal humerus is often regarded as consisting of four parts, which assists in understanding function and, more specially, describes the essential parts in reconstruction after fracture or in joint replacement. These are the

  16. [Contributions of SGLT-2 and new drugs under investigation].

    Science.gov (United States)

    Mediavilla Bravo, J J

    2014-07-01

    DeFronzo spoke of the "ominous octet", in which he referred to the existence of distinct pathways and organs related to the physiopathology of type 2 diabetes mellitus (DM2). One of these key organs is the kidney, which plays an important role in regulating glucose metabolism through gluconeogenesis and through glomerular filtration and glucose reabsorption in the proximal convoluted tubules. Approximately 180 g of glucose are filtered to the renal tubule from the blood stream through the glomerulus. The filtrate is subsequently reabsorbed from the tubules to the peritubular capillaries through the action of sodium glucose cotransporters (SGLT). There are 2 main cotransporters in the kidney, SGLT1 and SGLT2, which reabsorb the glucose (10% and 90%, respectively) and return it to the blood. In persons with DM2, SGLT2 is increased, leading to greater renal absorption of glucose, which has adverse effects as it contributes to the maintenance of hyperglycemia. Selective pharmacological SGLT2 inhibition increases renal glucose excretion and secondarily reduces its plasma values. SGLT2 inhibitors act exclusively on the kidney, reduce glycosylated hemoglobin (HbA1c) by about 0.66%, decrease blood pressure, and induce a weight loss of approximately 1.8 kg. These drugs have a low risk of hypoglycemia but carry an increased risk of genitourinary infections. Several clinical trials have shown that dapagliflozin (10mg/day), the first SGLT2 inhibitor commercialized in Spain, produces a statistically significant reduction in HbA1c of 0.82-0.97%, both in monotherapy and in combination with metformin, glimepiride, pioglitazone, or insulin. Its use produces a weight loss of between 2 and 3 kg and reduces both systolic and diastolic blood pressure, while the risk of hypoglycemias is low. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

  17. SwissProt search result: AK104786 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104786 001-039-D11 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 2e-37 ...

  18. SwissProt search result: AK067792 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK067792 J013118N06 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel pr...otein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 2e-37 ...

  19. SwissProt search result: AK058323 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058323 001-014-B07 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 2e-44 ...

  20. SwissProt search result: AK059438 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK059438 001-027-G11 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 2e-14 ...

  1. 50 Years of renal physiology from one man and the perfused tubule: Maurice B. Burg.

    Science.gov (United States)

    Hamilton, Kirk L; Moore, Antoni B

    2016-08-01

    Technical advancements in research techniques in science are made in slow increments. Even so, large advances from insight and hard work of an individual with a single technique can have astonishing ramifications. Here, we examine the impact of Dr. Maurice B. Burg and the isolated perfused renal tubule technique and celebrate the 50th anniversary of the publication by Dr. Burg and his colleagues of their landmark paper in the American Journal of Physiology in 1966. In this study, we have taken a scientific visualization approach to study the scientific contributions of Dr. Burg and the isolated perfused tubule preparation as determining research impact by the number of research students, postdoctoral fellows, visiting scientists, and national and international collaborators. Additionally, we have examined the research collaborations (first and second generation scientists), established the migrational visualization of the first generation scientists who worked directly with Dr. Burg, quantified the metrics indices, identified and quantified the network of coauthorship of the first generation scientists with their second generation links, and determined the citations analyses of outputs of Dr. Burg and/or his first generation collaborators as coauthors. We also review the major advances in kidney physiology that have been made with the isolated perfused tubule technique. Finally, we are all waiting for the discoveries that the isolated perfused preparation technique will bring during the next 50 years. Copyright © 2016 the American Physiological Society.

  2. microRNA-143 down-regulates Hexokinase 2 in colon cancer cells

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Jacobsen, Anders; Frankel, Lisa

    2012-01-01

    a significant enrichment of miR-143 seed sites in their 3' UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion. CONCLUSION: We have identified...... and validated HK2 as a miR-143 target. Furthermore, our results indicate that miR-143 mediated down-regulation of HK2 affects glucose metabolism in colon cancer cells. We hypothesize that loss of miR-143-mediated repression of HK2 can promote glucose metabolism in cancer cells, contributing to the shift towards......ABSTRACT: BACKGROUND: MicroRNAs (miRNAs) are well recognized as gene regulators and have been implicated in the regulation of development as well as human diseases. miR-143 is located at a fragile site on chromosome 5 frequently deleted in cancer, and has been reported to be down...

  3. A new topology of the HK97-like fold revealed in Bordetella bacteriophage by cryoEM at 3.5 Å resolution

    Science.gov (United States)

    Zhang, Xing; Guo, Huatao; Jin, Lei; Czornyj, Elizabeth; Hodes, Asher; Hui, Wong H; Nieh, Angela W; Miller, Jeff F; Zhou, Z Hong

    2013-01-01

    Bacteriophage BPP-1 infects and kills Bordetella species that cause whooping cough. Its diversity-generating retroelement (DGR) provides a naturally occurring phage-display system, but engineering efforts are hampered without atomic structures. Here, we report a cryo electron microscopy structure of the BPP-1 head at 3.5 Å resolution. Our atomic model shows two of the three protein folds representing major viral lineages: jellyroll for its cement protein (CP) and HK97-like (‘Johnson’) for its major capsid protein (MCP). Strikingly, the fold topology of MCP is permuted non-circularly from the Johnson fold topology previously seen in viral and cellular proteins. We illustrate that the new topology is likely the only feasible alternative of the old topology. β-sheet augmentation and electrostatic interactions contribute to the formation of non-covalent chainmail in BPP-1, unlike covalent inter-protein linkages of the HK97 chainmail. Despite these complex interactions, the termini of both CP and MCP are ideally positioned for DGR-based phage-display engineering. DOI: http://dx.doi.org/10.7554/eLife.01299.001 PMID:24347545

  4. Ankyrin-B coordinates the Na/K ATPase, Na/Ca exchanger, and InsP3 receptor in a cardiac T-tubule/SR microdomain.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available We report identification of an ankyrin-B-based macromolecular complex of Na/K ATPase (alpha 1 and alpha 2 isoforms, Na/Ca exchanger 1, and InsP3 receptor that is localized in cardiomyocyte T-tubules in discrete microdomains distinct from classic dihydropyridine receptor/ryanodine receptor "dyads." E1425G mutation of ankyrin-B, which causes human cardiac arrhythmia, also blocks binding of ankyrin-B to all three components of the complex. The ankyrin-B complex is markedly reduced in adult ankyrin-B(+/- cardiomyocytes, which may explain elevated [Ca2+]i transients in these cells. Thus, loss of the ankyrin-B complex provides a molecular basis for cardiac arrhythmia in humans and mice. T-tubule-associated ankyrin-B, Na/Ca exchanger, and Na/K ATPase are not present in skeletal muscle, where ankyrin-B is expressed at 10-fold lower levels than in heart. Ankyrin-B also is not abundantly expressed in smooth muscle. We propose that the ankyrin-B-based complex is a specialized adaptation of cardiomyocytes with a role for cytosolic Ca2+ modulation.

  5. Predicted consequences of diabetes and SGLT inhibition on transport and oxygen consumption along a rat nephron

    Science.gov (United States)

    Vallon, Volker; Edwards, Aurélie

    2016-01-01

    Diabetes increases the reabsorption of Na+ (TNa) and glucose via the sodium-glucose cotransporter SGLT2 in the early proximal tubule (S1-S2 segments) of the renal cortex. SGLT2 inhibitors enhance glucose excretion and lower hyperglycemia in diabetes. We aimed to investigate how diabetes and SGLT2 inhibition affect TNa and sodium transport-dependent oxygen consumption QO2active along the whole nephron. To do so, we developed a mathematical model of water and solute transport from the Bowman space to the papillary tip of a superficial nephron of the rat kidney. Model simulations indicate that, in the nondiabetic kidney, acute and chronic SGLT2 inhibition enhances active TNa in all nephron segments, thereby raising QO2active by 5–12% in the cortex and medulla. Diabetes increases overall TNa and QO2active by ∼50 and 100%, mainly because it enhances glomerular filtration rate (GFR) and transport load. In diabetes, acute and chronic SGLT2 inhibition lowers QO2active in the cortex by ∼30%, due to GFR reduction that lowers proximal tubule active TNa, but raises QO2active in the medulla by ∼7%. In the medulla specifically, chronic SGLT2 inhibition is predicted to increase QO2active by 26% in late proximal tubules (S3 segments), by 2% in medullary thick ascending limbs (mTAL), and by 9 and 21% in outer and inner medullary collecting ducts (OMCD and IMCD), respectively. Additional blockade of SGLT1 in S3 segments enhances glucose excretion, reduces QO2active by 33% in S3 segments, and raises QO2active by SGLT2 blockade in diabetes lowers cortical QO2active and raises medullary QO2active, particularly in S3 segments. PMID:26764207

  6. Effects of induced Na+/Ca2+ exchanger overexpression on the spatial distribution of L-type Ca2+ channels and junctophilin-2 in pressure-overloaded hearts.

    Science.gov (United States)

    Ujihara, Yoshihiro; Mohri, Satoshi; Katanosaka, Yuki

    2016-11-25

    The Na + /Ca 2+ exchanger 1 (NCX1) is an essential Ca 2+ efflux system in cardiomyocytes. Although NCX1 is distributed throughout the sarcolemma, a subpopulation of NCX1 is localized to transverse (T)-tubules. There is growing evidence that T-tubule disorganization is a causal event that shifts the transition from hypertrophy to heart failure (HF). However, the detailed molecular mechanisms have not been clarified. Previously, we showed that induced NCX1 expression in pressure-overloaded hearts attenuates defective excitation-contraction coupling and HF progression. Here, we examined the effects of induced NCX1 overexpression on the spatial distribution of L-type Ca 2+ channels (LTCCs) and junctophilin-2 (JP2), a structural protein that connects the T-tubule and sarcoplasmic reticulum membrane, in pressure-overloaded hearts. Quantitative analysis showed that the regularity of NCX1 localization was significantly decreased at 8 weeks after transverse aortic constriction (TAC)-surgery; however, T-tubule organization and the regularities of LTCC and JP2 immunofluorescent signals were maintained at this time point. These observations demonstrated that release of NCX1 from the T-tubule area occurred before the onset of T-tubule disorganization and LTCC and JP2 mislocalization. Moreover, induced NCX1 overexpression at 8 weeks post-TAC not only recovered NCX1 regularity but also prevented the decrease in LTCC and JP2 regularities at 16 weeks post-TAC. These results suggested that NCX1 may play an important role in the proper spatial distribution of LTCC and JP2 in T-tubules in the context of pressure-overloading. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The testicular sperm ducts and genital kidney of male Ambystoma maculatum (Amphibia, Urodela, Ambystomatidae).

    Science.gov (United States)

    Siegel, Dustin S; Aldridge, Robert D; Rheubert, Justin L; Gribbins, Kevin M; Sever, David M; Trauth, Stanley E

    2013-03-01

    The ducts associated with sperm transport from the testicular lobules to the Wolffian ducts in Ambystoma maculatum were examined with transmission electron microscopy. Based on the ultrastructure and historical precedence, new terminology for this network of ducts is proposed that better represents primary hypotheses of homology. Furthermore, the terminology proposed better characterizes the distinct regions of the sperm transport ducts in salamanders based on anatomy and should, therefore, lead to more accurate comparisons in the future. While developing the above ontology, we also tested the hypothesis that nephrons from the genital kidney are modified from those of the pelvic kidney due to the fact that the former nephrons function in sperm transport. Our ultrastructural analysis of the genital kidney supports this hypothesis, as the basal plasma membrane of distinct functional regions of the nephron (proximal convoluted tubule, distal convoluted tubule, and collecting tubule) appear less folded (indicating decreased surface area and reduced reabsorption efficiency) and the proximal convoluted tubule possesses ciliated epithelial cells along its entire length. Furthermore, visible luminal filtrate is absent from the nephrons of the genital kidney throughout their entire length. Thus, it appears that the nephrons of the genital kidney have reduced reabsorptive capacity and ciliated cells of the proximal convoluted tubule may increase the movement of immature sperm through the sperm transport ducts or aid in the mixing of seminal fluids within the ducts. Copyright © 2012 Wiley Periodicals, Inc.

  8. Pengaruh Pemberian Valsartan Dan Kurkumin Terhadap Pembentukan Fibrosis Di Tubulus Proksimal Ginjal Akibat Obstruksi Ureter Unilateral pada Tikus Wistar.

    Directory of Open Access Journals (Sweden)

    Lubis M

    2013-01-01

    . Perbedaan bermakna terbentuKata kunci: Obstruksi ureter, Valsartan, Kurkumin, Fibrosis, Degenerasi hidrofilik, AtrofiAbstractIntroduction: ureter obstruction is a condition where is an obstacle for urine flow from renal to blast (vesica urinaria. The obstruction in ureter will decrease glomerulus filtration flow and it destroys renal parenchym. Fibroses in obstructed renal present through two mediators, there are necrotizing tumor factors-α (TNF-α and angiotension-II. Obstruction of this two mediators will decrease fibroses grading in proximal tubules of renal caused by obtruction. One of TNF-α inhibitors is curcumene and angiotension-II will be obstructed by valsartan. Methods: this experiment is kind of experimental type using animal experiment (Wistar Mice. Wistar Mice are divided into two groups, each group consist of 15 mice, so the total are 30 mice. This animals tighted with at proximal ureter The first group is control one, given valsartan. The second group is given valsartan and curcumene. Oral route and dilution before given. Medicine is given use 1 cc spuit. Giving action in 14 days. The fifteenth day, we take renal of Wistar and do histology examination. Significant difference between fibroses forming in proximal tubulus analyzed by Chi Square Statistic Test with correction of Yates and T-Test, beside that, hydofic degeneration and atrophy in proximal tubulus analyzed by T-Test Statistic Test. Result: there is significant difference in forming of fibroses in proximal tubules of renal between action group and controlled group (Chi Square with p ≤ 0.0001 and T-Test with p ≤ 0.000. In hydrophilic degeneration forming in proximal tubules gotten significant difference between two groups ( T-Test with p ≤ 0.000. In atrophy forming in proximal tubules, there is important difference between two groups (T-Test with p ≤ 0.000.Concultion. There is an effect in giving valsartan and curcumene to fibroses forming in proximal tubules of renal. There is significant

  9. Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport

    Directory of Open Access Journals (Sweden)

    Nobuhiko Satoh

    2015-01-01

    Full Text Available A serine/threonine kinase Akt is a key mediator in various signaling pathways including regulation of renal tubular transport. In proximal tubules, Akt mediates insulin signaling via insulin receptor substrate 2 (IRS2 and stimulates sodium-bicarbonate cotransporter (NBCe1, resulting in increased sodium reabsorption. In insulin resistance, the IRS2 in kidney cortex is exceptionally preserved and may mediate the stimulatory effect of insulin on NBCe1 to cause hypertension in diabetes via sodium retention. Likewise, in distal convoluted tubules and cortical collecting ducts, insulin-induced Akt phosphorylation mediates several hormonal signals to enhance sodium-chloride cotransporter (NCC and epithelial sodium channel (ENaC activities, resulting in increased sodium reabsorption. Serum- and glucocorticoid-inducible kinase 1 (SGK1 mediates aldosterone signaling. Insulin can stimulate SGK1 to exert various effects on renal transporters. In renal cortical collecting ducts, SGK1 regulates the expression level of ENaC through inhibition of its degradation. In addition, SGK1 and Akt cooperatively regulate potassium secretion by renal outer medullary potassium channel (ROMK. Moreover, sodium-proton exchanger 3 (NHE3 in proximal tubules is possibly activated by SGK1. This review focuses on recent advances in understanding of the roles of Akt and SGK1 in the regulation of renal tubular transport.

  10. Pentraxin 3 Activates JNK Signaling and Regulates the Epithelial-To-Mesenchymal Transition in Renal Fibrosis

    Directory of Open Access Journals (Sweden)

    Tung-Wei Hung

    2016-12-01

    Full Text Available Background/Aims: Tubulointerstitial fibrosis can lead to end-stage renal disease. Pentraxin 3 (PTX3 is an acute phase protein produced by resident and innate immunity cells. We investigated the effect of PTX3 on cultured human proximal tubular epithelial (HK-2 cells and a rat unilateral ureteral obstruction (UUO model of renal fibrosis. Methods: Gain-of-function experiments were used to examine the effect of recombinant human PTX3 (Rh-PTX3 on HK-2 cells. Cell proliferation (MTT assay and in vitro cell migration were measured. The levels of PTX3, p-JNK, and EMT markers were measured using immunohistochemistry, RT-PCR, and western blotting in UUO rats and HK-2 cells. Results: HK-2 cells treated with Rh PTX3 did not affect cell viability, but significantly increased cell migration. Moreover, Rh-PTX3 increased the expression of snail, slug, N-cadherin, and vimentin, decreased the expression of E-cadherin, and increased the phosphorylation of JNK. SP600126 (a specific JNK inhibitor enhanced the effects of Rh-PTX3. Rats with UUO exhibited time-dependent increased levels of PTX3, p-JNK, and vimentin, and decreased expression of E-cadherin. Conclusions: Our results suggest that PTX3 induces cell migration via upregulation of EMT in a JNK-dependent mechanism, and highlight the role of PTX3 in the pathogenesis renal fibrosis.

  11. Digital contrast subtraction radiography for proximal caries diagnosis

    International Nuclear Information System (INIS)

    Kang, Byung Cheol; Yoon, Suk Ja

    2002-01-01

    To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Thirty-six teeth with 57 proximal surfaces were radiographied using a size no.2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

  12. Renal denervation prevents long-term sequelae of ischemic renal injury

    Science.gov (United States)

    Kim, Jinu; Padanilam, Babu J.

    2014-01-01

    Signals that drive interstitial fibrogenesis after renal ischemia reperfusion injury remain undefined. Sympathetic activation is manifest even in the early clinical stages of chronic kidney disease and is directly related to disease severity. A role for renal nerves in renal interstitial fibrogenesis in the setting of ischemia reperfusion injury has not been studied. In male 129S1/SvImJ mice, ischemia reperfusion injury induced tubulointerstitial fibrosis as indicated by collagen deposition and profibrotic protein expression 4 to 16 days after the injury.. Leukocyte influx, proinflammatory protein expression, oxidative stress, apoptosis, and cell cycle arrest at G2/M phase were enhanced after ischemia reperfusion injury. Renal denervation at the time of injury or up to 1 day post-injury improved histology, decreased proinflammatory/profibrotic responses and apoptosis, and prevented G2/M cell cycle arrest in the kidney. Treatment with afferent nerve-derived calcitonin gene-related peptide (CGRP) or efferent nerve-derived norepinephrine in denervated and ischemia reperfusion injury-induced kidneys mimicked innervation, restored inflammation and fibrosis, induced G2/M arrest, and enhanced TGF-β1 activation. Blocking norepinephrine or CGRP function using respective receptor blockers prevented these effects. Consistent with the in vivo study, treatment with either norepinephrine or CGRP induced G2/M cell cycle arrest in HK-2 proximal tubule cells, whereas antagonists against their respective receptors prevented G2/M arrest. Thus, renal nerve stimulation is a primary mechanism and renal nerve-derived factors drive epithelial cell cycle arrest and the inflammatory cascade causing interstitial fibrogenesis after ischemia reperfusion injury. PMID:25207878

  13. Distribution of anticancer antibiotic daunomycin in the rat heart and kidney revealed by immunocytochemistry using monoclonal antibodies

    DEFF Research Database (Denmark)

    Fujiwara, Kunio; Shin, Masashi; Hougaard, David M.

    2007-01-01

    .v. or i.p. administration of the drug. In the heart, accumulation of DM occurred in nuclei and in the cytoplasm. In the kidney, DM immunoreactivity accumulated in all segments of the nephron except for the proximal tubules. Since the proximal tubules are known to be where a variety of transport systems...... possibilities for understanding toxic side effects of this drug on the heart and kidney. Moreover, the immunocytochemical methodology developed may prove useful for the localization of other low molecular weight drugs that can be fixed in situ by glutaraldehyde....

  14. Characterization of the chemical reactivity and nephrotoxicity of N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide, a potential reactive metabolite of trichloroethylene.

    Science.gov (United States)

    Irving, Roy M; Pinkerton, Marie E; Elfarra, Adnan A

    2013-02-15

    N-Acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NA-DCVC) has been detected in the urine of humans exposed to trichloroethylene and its related sulfoxide, N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (NA-DCVCS), has been detected as hemoglobin adducts in blood of rats dosed with S-(1,2-dichlorovinyl)-L-cysteine (DCVC) or S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (DCVCS). Because the in vivo nephrotoxicity of NA-DCVCS was unknown, in this study, male Sprague-Dawley rats were dosed (i.p.) with 230 μmol/kg b.w. NA-DCVCS or its potential precursors, DCVCS or NA-DCVC. At 24 h post treatment, rats given NA-DCVC or NA-DCVCS exhibited kidney lesions and effects on renal function distinct from those caused by DCVCS. NA-DCVC and NA-DCVCS primarily affected the cortico-medullary proximal tubules (S(2)-S(3) segments) while DCVCS primarily affected the outer cortical proximal tubules (S(1)-S(2) segments). When NA-DCVCS or DCVCS was incubated with GSH in phosphate buffer pH 7.4 at 37°C, the corresponding glutathione conjugates were detected, but NA-DCVC was not reactive with GSH. Because NA-DCVCS exhibited a longer half-life than DCVCS and addition of rat liver cytosol enhanced GSH conjugate formation, catalysis of GSH conjugate formation by the liver could explain the lower toxicity of NA-DCVCS in comparison with DCVCS. Collectively, these results provide clear evidence that NA-DCVCS formation could play a significant role in DCVC, NA-DCVC, and trichloroethylene nephrotoxicity. They also suggest a role for hepatic metabolism in the mechanism of NA-DCVC nephrotoxicity. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Elucidation of density profile of self-assembled sitosterol + oryzanol tubules with small-angle neutron scattering

    NARCIS (Netherlands)

    Bot, A.; Gilbert, E.P.; Bouwman, W.G.; Sawalha, H.I.M.; Adel, den R.; Garamus, V.M.; Venema, P.; Linden, van der E.; Flöter, E.

    2012-01-01

    Small-angle neutron scattering (SANS) experiments have been performed on self-assembled tubules of sitosterol and oryzanol in triglyceride oils to investigate details of their structure. Alternative organic phases (deuterated and non-deuterated decane, limonene, castor oil and eugenol) were used to

  16. The breast cancer resistance protein transporter ABCG2 is expressed in the human kidney proximal tubule apical membrane.

    NARCIS (Netherlands)

    Huls, M.; Brown, C.D.; Windass, A.S.; Sayer, R.; Heuvel, J.J.M.W. van den; Heemskerk, S.; Russel, F.G.M.; Masereeuw, R.

    2008-01-01

    The Breast Cancer Resistance Protein (BCRP/ABCG2) is a transporter restricting absorption and enhancing excretion of many compounds including anticancer drugs. This transporter is highly expressed in many tissues; however, in human kidney, only the mRNA was found in contrast to the mouse kidney,

  17. Elemental imaging of kidneys of adult rats exposed to uranium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Homma-Takeda, S. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)], E-mail: shino_ht@nirs.go.jp; Terada, Y. [Japan Synchrotron Radiation Research Institute, Mikazuki, Hyogo 679-5198 (Japan); Nakata, A.; Sahoo, S.K.; Yoshida, S. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ueno, S. [School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628 (Japan); Inoue, M. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Iso, H.; Ishikawa, T.; Konishi, T.; Imaseki, H. [Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shimada, Y. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2009-06-15

    Concern about the toxicity of depleted uranium for military use has increased recently. Renal toxicity is the hallmark effect of uranium exposure. However, the dynamics and distribution of uranium in the kidney are not well understood. Here, we determined the precise distribution of uranium and essential elements in the rat kidney using microbeam scanning particle-induced X-ray emission (micro-PIXE) and synchrotron radiation X-ray fluorescence (SR-XRF). Uranium accumulation in the rat kidney reached a maximum at 1 day after the subcutaneous (s.c.) administration of 2 mg U/kg of uranium acetate and then gradually decreased. At 3 h after administration, uranium was distributed mainly in the proximal tubules of the inner zone of the cortex and in the outer stripe of the outer medulla, and absorbed by the proximal tubule epithelium. Iron was localized more in the inside of the outer medulla than uranium, while phosphorus, potassium, sulfur and zinc were equally distributed in the cortex and the outer stripe of the outer medulla. At 3 days after administration, the number of apoptotic cells increased and cells were lost from the proximal tubules. Uranium was detectable mainly in the outer stripe of the outer medulla at 15 days, suggesting that the renal distribution of uranium is site-selective and causes site-specific renal lesions.

  18. Equivalent complex conductivities representing the effects of T-tubules and folded surface membranes on the electrical admittance and impedance of skeletal muscles measured by external-electrode method

    Science.gov (United States)

    Sekine, Katsuhisa

    2017-12-01

    In order to represent the effects of T-tubules and folded surface membranes on the electrical admittance and impedance of skeletal muscles measured by the external-electrode method, analytical relations for the equivalent complex conductivities of hypothetical smooth surface membranes were derived. In the relations, the effects of each tubule were represented by the admittance of a straight cable. The effects of the folding of a surface membrane were represented by the increased area of surface membranes. The equivalent complex conductivities were represented as summation of these effects, and the effects of the T-tubules were different between the transversal and longitudinal directions. The validity of the equivalent complex conductivities was supported by the results of finite-difference method (FDM) calculations made using three-dimensional models in which T-tubules and folded surface membranes were represented explicitly. FDM calculations using the equivalent complex conductivities suggested that the electrically inhomogeneous structure due to the existence of muscle cells with T-tubules was sufficient for explaining the experimental results previously obtained using the external-electrode method. Results of FDM calculations in which the structural changes caused by muscle contractions were taken into account were consistent with the reported experimental results.

  19. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2, wh...

  20. Quantum Proximity Resonances

    International Nuclear Information System (INIS)

    Heller, E.J.

    1996-01-01

    It is well known that at long wavelengths λ an s-wave scatterer can have a scattering cross section σ on the order of λ 2 , much larger than its physical size, as measured by the range of its potential. Very interesting phenomena can arise when two or more identical scatterers are placed close together, well within one wavelength. We show that, for a pair of identical scatterers, an extremely narrow p-wave open-quote open-quote proximity close-quote close-quote resonance develops from a broader s-wave resonance of the individual scatterers. A new s-wave resonance of the pair also appears. The relation of these proximity resonances (so called because they appear when the scatterers are close together) to the Thomas and Efimov effects is discussed. copyright 1996 The American Physical Society

  1. A computational model for simulating solute transport and oxygen consumption along the nephrons

    Science.gov (United States)

    Vallon, Volker; Edwards, Aurélie

    2016-01-01

    The goal of this study was to investigate water and solute transport, with a focus on sodium transport (TNa) and metabolism along individual nephron segments under differing physiological and pathophysiological conditions. To accomplish this goal, we developed a computational model of solute transport and oxygen consumption (QO2) along different nephron populations of a rat kidney. The model represents detailed epithelial and paracellular transport processes along both the superficial and juxtamedullary nephrons, with the loop of Henle of each model nephron extending to differing depths of the inner medulla. We used the model to assess how changes in TNa may alter QO2 in different nephron segments and how shifting the TNa sites alters overall kidney QO2. Under baseline conditions, the model predicted a whole kidney TNa/QO2, which denotes the number of moles of Na+ reabsorbed per moles of O2 consumed, of ∼15, with TNa efficiency predicted to be significantly greater in cortical nephron segments than in medullary segments. The TNa/QO2 ratio was generally similar among the superficial and juxtamedullary nephron segments, except for the proximal tubule, where TNa/QO2 was ∼20% higher in superficial nephrons, due to the larger luminal flow along the juxtamedullary proximal tubules and the resulting higher, flow-induced transcellular transport. Moreover, the model predicted that an increase in single-nephron glomerular filtration rate does not significantly affect TNa/QO2 in the proximal tubules but generally increases TNa/QO2 along downstream segments. The latter result can be attributed to the generally higher luminal [Na+], which raises paracellular TNa. Consequently, vulnerable medullary segments, such as the S3 segment and medullary thick ascending limb, may be relatively protected from flow-induced increases in QO2 under pathophysiological conditions. PMID:27707705

  2. Effects of receptor-mediated endocytosis and tubular protein composition on volume retention in experimental glomerulonephritis

    DEFF Research Database (Denmark)

    Kastner, Christian; Pohl, Marcus; Sendeski, Mauricio

    2009-01-01

    Human glomerulonephritis (GN) is characterized by sustained proteinuria, sodium retention, hypertension, and edema formation. Increasing quantities of filtered protein enter the renal tubule, where they may alter epithelial transport functions. Exaggerated endocytosis and consequent protein...... overload may affect proximal tubules, but intrinsic malfunction of distal epithelia has also been reported. A straightforward assignment to a particular tubule segment causing salt retention in GN is still controversial. We hypothesized that 1) trafficking and surface expression of major transporters...

  3. Auto-regeneration of mice testicle seminiferous tubules due to malnutrition based on stem cells mobilization using honey

    Directory of Open Access Journals (Sweden)

    Erma Safitri

    2016-03-01

    Conclusions: Results of this study revealed a significantly different of C34 and CD45 expressions between groups, also an increase SSCs expression and testicle seminiferous tubules cells regeneration as well.

  4. A Role for Tubular Necroptosis in Cisplatin-Induced AKI

    Science.gov (United States)

    Xu, Yanfang; Ma, Huabin; Shao, Jing; Wu, Jianfeng; Zhou, Linying; Zhang, Zhirong; Wang, Yuze; Huang, Zhe; Ren, Junming; Liu, Suhuan; Chen, Xiangmei

    2015-01-01

    Cell death and inflammation in the proximal tubules are the hallmarks of cisplatin-induced AKI, but the mechanisms underlying these effects have not been fully elucidated. Here, we investigated whether necroptosis, a type of programmed necrosis, has a role in cisplatin-induced AKI. We found that inhibition of any of the core components of the necroptotic pathway—receptor-interacting protein 1 (RIP1), RIP3, or mixed lineage kinase domain-like protein (MLKL)—by gene knockout or a chemical inhibitor diminished cisplatin-induced proximal tubule damage in mice. Similar results were obtained in cultured proximal tubular cells. Furthermore, necroptosis of cultured cells could be induced by cisplatin or by a combination of cytokines (TNF-α, TNF-related weak inducer of apoptosis, and IFN-γ) that were upregulated in proximal tubules of cisplatin-treated mice. However, cisplatin induced an increase in RIP1 and RIP3 expression in cultured tubular cells in the absence of cytokine release. Correspondingly, overexpression of RIP1 or RIP3 enhanced cisplatin-induced necroptosis in vitro. Notably, inflammatory cytokine upregulation in cisplatin-treated mice was partially diminished in RIP3- or MLKL-deficient mice, suggesting a positive feedback loop involving these genes and inflammatory cytokines that promotes necroptosis progression. Thus, our data demonstrate that necroptosis is a major mechanism of proximal tubular cell death in cisplatin-induced nephrotoxic AKI. PMID:25788533

  5. Small supernumerary marker chromosome derived from proximal p-arm of chromosome 2: identification by fluorescent in situ hybridization.

    Science.gov (United States)

    Lasan Trcić, Ruzica; Hitrec, Vlasta; Letica, Ljiljana; Cuk, Mario; Begović, Davor

    2003-08-01

    Conventional cytogenetics detected an interstitial deletion of proximal region of p-arm of chromosome 2 in a 6-month-old boy with a phenotype slightly resembling Down's syndrome. The deletion was inherited from the father, whose karyotype revealed a small ring-shaped marker chromosome, in addition to interstitial deletion. Fluorescence in situ hybridization identified the marker, which consisted of the proximal region of the p-arm of chromosome 2, including a part of its centromere. This case shows that molecular cytogenetic analysis can reveal the mechanism of the formation of the marker chromosome.

  6. Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.

    Science.gov (United States)

    Chen, Wan-Chun; Lin, Hsi-Hui; Tang, Ming-Jer

    2014-09-15

    To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis. Copyright © 2014 the American Physiological Society.

  7. A de novo transcriptome of the Malpighian tubules in non-blood-fed and blood-fed Asian tiger mosquitoes Aedes albopictus: insights into diuresis, detoxification, and blood meal processing

    Directory of Open Access Journals (Sweden)

    Carlos J. Esquivel

    2016-03-01

    Full Text Available Background. In adult female mosquitoes, the renal (Malpighian tubules play an important role in the post-prandial diuresis, which removes excess ions and water from the hemolymph of mosquitoes following a blood meal. After the post-prandial diuresis, the roles that Malpighian tubules play in the processing of blood meals are not well described. Methods. We used a combination of next-generation sequencing (paired-end RNA sequencing and physiological/biochemical assays in adult female Asian tiger mosquitoes (Aedes albopictus to generate molecular and functional insights into the Malpighian tubules and how they may contribute to blood meal processing (3–24 h after blood ingestion. Results/Discussion. Using RNA sequencing, we sequenced and assembled the first de novo transcriptome of Malpighian tubules from non-blood-fed (NBF and blood-fed (BF mosquitoes. We identified a total of 8,232 non-redundant transcripts. The Malpighian tubules of NBF mosquitoes were characterized by the expression of transcripts associated with active transepithelial fluid secretion/diuresis (e.g., ion transporters, water channels, V-type H+-ATPase subunits, xenobiotic detoxification (e.g., cytochrome P450 monoxygenases, glutathione S-transferases, ATP-binding cassette transporters, and purine metabolism (e.g., xanthine dehydrogenase. We also detected the expression of transcripts encoding sodium calcium exchangers, G protein coupled-receptors, and septate junctional proteins not previously described in mosquito Malpighian tubules. Within 24 h after a blood meal, transcripts associated with active transepithelial fluid secretion/diuresis exhibited a general downregulation, whereas those associated with xenobiotic detoxification and purine catabolism exhibited a general upregulation, suggesting a reinvestment of the Malpighian tubules’ molecular resources from diuresis to detoxification. Physiological and biochemical assays were conducted in mosquitoes and isolated

  8. Comportamiento de las aleaciones termorresistentes AISI HH y HK-40 ante los procesos de carburización y nitruración

    Directory of Open Access Journals (Sweden)

    Eleno Alfonso-Brindis

    2001-03-01

    Full Text Available Se evalúa el comportamiento de los aceros austeníticos fundidos AISI HH y HK- 40 (de producción nacional ante los procesos de carburización y nitruración en los rangos de temperaturas desde 750 hasta 1 000 °C. Se estudia la cinética y la termodinámica de las posibles reacciones y los productos de las mismas se caracterizan mediante técnicas de Microscopía Óptica, Microscopía Electrónica de Barrido y Microanálisis (MEB-EDAX. En el análisis microscópico se observó la formación de carburos de cromo después de la carburización, mientras que la nitruración dio lugar a la formación de nitruros de cromo. Se concluye que la aleación AISI HK-40 posee una elevada resistencia intrínseca a la carburización y a la nitruración, que hace factible su empleo en componentes de hornos de soleras múltiples para la reducción de minerales lateríticos

  9. Synthesis and secretion of proteins by perifused caput epididymal tubules, and association of secreted proteins with spermatozoa

    International Nuclear Information System (INIS)

    Klinefelter, G.R.; Hamilton, D.W.

    1985-01-01

    We have used perifusion organ culture of proximal and distal caput epididymal tubules of the rat to study the secretion of proteins by epididymal epithelium and uptake of the luminal radioactive proteins by sperm. The amount of incorporation of L-[35S]methionine into luminal fluid proteins was time dependent and completely inhibited by cycloheximide. The association of labeled proteins with cultured sperm was also dependent on time and continuous, with sperm still acquiring labeled luminal proteins after protein synthesis was arrested. A Mr = 46,000 molecule was found to be heavily labeled in luminal fluid and sperm extracts. Fluorograms of all L-[35S]methionine extracts immunoprecipitated using an antiepididymal alpha-lactalbumin antibody (Klinefelter and Hamilton, 1984) showed labeling of an Mr = 18,000 molecule and, in addition, the Mr = 46,000 molecule, but immunostaining was specific only for the Mr = 18,000 molecule and the heavy chain of the immunoglobulin. We suggest that the Mr = 46,000 molecule may be galactosyltransferase. Galactose oxidase-NaB[3H]4 labeling of the cultured caput sperm cell surface revealed a Mr = 23,000 molecule that was able to be immunoprecipitated with antiepididymal alpha-lactalbumin antibody. Our data suggest that this cell surface molecule is similar to one component of the fluid epididymal alpha-lactalbumin-like complex and, in addition, show that glycosylation of the sperm surface can occur in the caput epididymidis

  10. Internal fixation of proximal fractures of the 2nd and 4th metacarpal and metatarsal bones using bioabsorbable screws.

    Science.gov (United States)

    Mageed, M; Steinberg, T; Drumm, N; Stubbs, N; Wegert, J; Koene, M

    2018-03-01

    Fractures involving the proximal one-third of the splint bone are relatively rare and are challenging to treat. A variety of management techniques have been reported in the literature. The aim of this retrospective case series was to describe the clinical presentation and evaluate the efficacy of bioabsorbable polylactic acid screws in internal fixation of proximal fractures of the 2nd and 4th metacarpal and metatarsal bones in horses. The medical records, diagnostic images and outcome of all horses diagnosed with a proximal fracture of the splint bones and treated with partial resection and internal fixation of the proximal stump using bioabsorbable polylactic acid screws between 2014 and 2015 were reviewed. Eight horses met the inclusion criteria. The results showed that there were no complications encountered during screw placement or postoperatively. Six horses returned to full work 3 months after the operation and two horses remained mildly lame. On follow-up radiographs 12 months postoperatively (n = 2) the screws were not completely absorbed. The screws resulted in a cone-shaped radiolucency, which was progressively replaced from the outer margins by bone sclerosis. The use of bioabsorbable screws for fixation of proximal fractures of the splint bone appears to be a safe and feasible technique and may offer several advantages over the use of traditional metallic implants. © 2018 Australian Veterinary Association.

  11. Collective cell migration drives morphogenesis of the kidney nephron.

    Directory of Open Access Journals (Sweden)

    Aleksandr Vasilyev

    2009-01-01

    Full Text Available Tissue organization in epithelial organs is achieved during development by the combined processes of cell differentiation and morphogenetic cell movements. In the kidney, the nephron is the functional organ unit. Each nephron is an epithelial tubule that is subdivided into discrete segments with specific transport functions. Little is known about how nephron segments are defined or how segments acquire their distinctive morphology and cell shape. Using live, in vivo cell imaging of the forming zebrafish pronephric nephron, we found that the migration of fully differentiated epithelial cells accounts for both the final position of nephron segment boundaries and the characteristic convolution of the proximal tubule. Pronephric cells maintain adherens junctions and polarized apical brush border membranes while they migrate collectively. Individual tubule cells exhibit basal membrane protrusions in the direction of movement and appear to establish transient, phosphorylated Focal Adhesion Kinase-positive adhesions to the basement membrane. Cell migration continued in the presence of camptothecin, indicating that cell division does not drive migration. Lengthening of the nephron was, however, accompanied by an increase in tubule cell number, specifically in the most distal, ret1-positive nephron segment. The initiation of cell migration coincided with the onset of fluid flow in the pronephros. Complete blockade of pronephric fluid flow prevented cell migration and proximal nephron convolution. Selective blockade of proximal, filtration-driven fluid flow shifted the position of tubule convolution distally and revealed a role for cilia-driven fluid flow in persistent migration of distal nephron cells. We conclude that nephron morphogenesis is driven by fluid flow-dependent, collective epithelial cell migration within the confines of the tubule basement membrane. Our results establish intimate links between nephron function, fluid flow, and morphogenesis.

  12. Effect of Hypodynamy on Structure and Alkaline Phosphatase Activity of Kidney in Japanese Quails

    Directory of Open Access Journals (Sweden)

    V. Almášiová

    2008-01-01

    Full Text Available The objective of the study was to observe the effect of experimental hypodynamy simulating weightlessness in space on the structure, ultrastructure and alkaline phosphatase activity of kidney in Japanese quail (Coturnix coturnix japonica. Two days after hatching, the quails were suspended in special shirts below the cage ceiling so their feet did not touch the floor. They could consume food and water ad libitum. Experimental animals were sacrificed after 14, 21, 28, 35, 42, 49 and 56 days of hypodynamy. Birds of the same age, hatched at the same time, and fed the same diet were used as a control. Samples of kidney were processed for light (LM and transmission electron microscopy (TEM, and alkaline phosphatase (AP analysis. Short-term (14–28 days hypodynamy caused no marked damage to the structure and ultrastructure of kidneys. However, after long-term (35–59 days hypodynamy, morphological changes were observed in some cells of the proximal and distal tubules. The dying cells in proximal tubules, observed in semi-thin sections by LM, were dark and contained a nucleus of irregular shape. Observation by TEM showed that their nucleus was dark and shrivelled and the electron-dense cytoplasm contained long, dense, rod-shaped mitochondria with thin mitochondrial cristae. Microvilli were present on the apical surface of cells and formed a brush border. Sporadic dying cells were also observed in distal tubules. Large, light vacuoles were found in the cytoplasm of cells of collecting tubules, however, the structure of renal corpuscles and medullary loops remained undisturbed. Microscopical analysis by means of a direct TUNEL reaction on days 35 to 59 of hypodynamy showed a moderate occurrence of cellular apoptosis in the proximal and distal tubules of experimental Japanese quail. The activity of AP in the brush border of the proximal tubules on days 14–29 of hypodynamy was normal in experimental animals and showed no significant differences in

  13. A dual-mode proximity sensor with integrated capacitive and temperature sensing units

    International Nuclear Information System (INIS)

    Qiu, Shihua; Huang, Ying; He, Xiaoyue; Sun, Zhiguang; Liu, Ping; Liu, Caixia

    2015-01-01

    The proximity sensor is one of the most important devices in the field of robot application. It can accurately provide the proximity information to assistant robots to interact with human beings and the external environment safely. In this paper, we have proposed and demonstrated a dual-mode proximity sensor composed of capacitive and resistive sensing units. We defined the capacitive type proximity sensor perceiving the proximity information as C-mode and the resistive type proximity sensor detecting as R-mode. Graphene nanoplatelets (GNPs) were chosen as the R-mode sensing material because of its high performance. The dual-mode proximity sensor presents the following features: (1) the sensing distance of the dual-mode proximity sensor has been enlarged compared with the single capacitive proximity sensor in the same geometrical pattern; (2) experiments have verified that the proposed sensor can sense the proximity information of different materials; (3) the proximity sensing capability of the sensor has been improved by two modes perceive collaboratively, for a plastic block at a temperature of 60 °C: the R-mode will perceive the proximity information when the distance d between the sensor and object is 6.0–17.0 mm and the C-mode will do that when their interval is 0–2.0 mm; additionally two modes will work together when the distance is 2.0–6.0 mm. These features indicate our transducer is very valuable in skin-like sensing applications. (paper)

  14. Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

    Directory of Open Access Journals (Sweden)

    Minghua Xu

    2014-01-01

    Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

  15. [SGLT2 inhibitors: a new therapeutic class for the treatment of type 2 diabetes mellitus].

    Science.gov (United States)

    Dagan, Amir; Dagan, Bracha; SegaL, Gad

    2015-03-01

    SGLT2 (Sodium Glucose co-Transporter 2 Inhibitors) inhibitors are a new group of oral medications for the treatment of type 2 diabetes mellitus patients. These medications interfere with the process of glucose reabsorption in the proximal convoluted tubules in the kidneys, therefore increasing both glucose and water diuresis. SGLT2 inhibitors were found to be effective in lowering HbA1c levels in double-blinded studies, both as monotherapy and in combination with other oral hypoglycemic medications of various other mechanisms of action. SGLT2 Inhibitors are not a risk factor for hypoglycemia and are suitable for combination with insulin therapy. Their unique mode of action, relying on glomerular filtration, make these medication unsuitable for usage as treatment for type 2 diabetes patients who are also suffering from moderate to severe renal failure. Their main adverse effects are increased risk for urinary and genital tract infections. The following review describes the relevant pathophysiology addressed by these novel medications, evidence for efficacy and the safety profile of SGLT2 Inhibitors.

  16. Promoting proximal formative assessment with relational discourse

    Science.gov (United States)

    Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

    2012-02-01

    The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

  17. The truncated Hyper-Poisson queues: Hk/Ma,b/C/N with balking, reneging and general bulk service rule

    Directory of Open Access Journals (Sweden)

    Shawky A.I.

    2008-01-01

    Full Text Available The aim of this paper is to derive the analytical solution of the queue: Hk/Ma,b/C/N with balking and reneging in which (I units arrive according to a hyper-Poisson distribution with k independent branches, (II the queue discipline is FIFO; and (III the units are served in batches according to a general bulk service rule. The steady-state probabilities, recurrence relations connecting various probabilities introduced are found and the expected number of units in the queue is derived in an explicit form. Also, some special cases are obtained. .

  18. Superconductivity proximate to antiferromagnetism in a copper-oxide monolayer grown on Bi2Sr2CaCu2O8 +δ

    Science.gov (United States)

    Wang, Shuai; Zhang, Long; Wang, Fa

    2018-01-01

    A nodeless superconducting (SC) gap was reported in a recent scanning tunneling spectroscopy experiment of a copper-oxide monolayer grown on a Bi2Sr2CaCu2O8 +δ (Bi2212) substrate [Zhong et al., Sci. Bull. 61, 1239 (2016), 10.1007/s11434-016-1145-4], which is in stark contrast to the nodal d -wave pairing gap in the bulk cuprates. Motivated by this experiment, we first show with first-principles calculations that the tetragonal CuO (T-CuO) monolayer on the Bi2212 substrate is more stable than the commonly postulated CuO2 structure. The T-CuO monolayer is composed of two CuO2 layers sharing the same O atoms. The band structure is obtained by first-principles calculations, and its strong electron correlation is treated with the renormalized mean-field theory. We argue that one CuO2 sublattice is hole doped while the other sublattice remains half filled and may have antiferromagnetic (AF) order. The doped Cu sublattice can show d -wave SC; however, its proximity to the AF Cu sublattice induces a spin-dependent hopping, which splits the Fermi surface and may lead to a full SC gap. Therefore, the nodeless SC gap observed in the experiment could be accounted for by the d -wave SC proximity to an AF order, thus it is extrinsic rather than intrinsic to the CuO2 layers.

  19. Dose and time relations in Hg(++)-induced tubular necrosis and regeneration

    DEFF Research Database (Denmark)

    Nielsen, J B; Andersen, H R; Andersen, O

    1994-01-01

    relationship is caused by a dose-related induction of kidney damage leading to increasing leakage of mercury through the kidneys. Histopathologic investigation revealed extensive necrosis of the proximal tubules in kidneys from mice exposed to 100 mumole HgCl2/kg or higher doses. Moreover, maximum renal damage...

  20. In vitro biomechanical properties of 2 compression fixation methods for midbody proximal sesamoid bone fractures in horses.

    Science.gov (United States)

    Woodie, J B; Ruggles, A J; Litsky, A S

    2000-01-01

    To evaluate 2 methods of midbody proximal sesamoid bone repair--fixation by a screw placed in lag fashion and circumferential wire fixation--by comparing yield load and the adjacent soft-tissue strain during monotonic loading. Experimental study. 10 paired equine cadaver forelimbs from race-trained horses. A transverse midbody osteotomy of the medial proximal sesamoid bone (PSB) was created. The osteotomy was repaired with a 4.5-mm cortex bone screw placed in lag fashion or a 1.25-mm circumferential wire. The limbs were instrumented with differential variable reluctance transducers placed in the suspensory apparatus and distal sesamoidean ligaments. The limbs were tested in axial compression in a single cycle until failure. The cortex bone screw repairs had a mean yield load of 2,908.2 N; 1 limb did not fail when tested to 5,000 N. All circumferential wire repairs failed with a mean yield load of 3,406.3 N. There was no statistical difference in mean yield load between the 2 repair methods. The maximum strain generated in the soft tissues attached to the proximal sesamoid bones was not significantly different between repair groups. All repaired limbs were able to withstand loads equal to those reportedly applied to the suspensory apparatus in vivo during walking. Each repair technique should have adequate yield strength for repair of midbody fractures of the PSB immediately after surgery.

  1. Aldosterone signaling regulates the over-expression of claudin-4 and -8 at the distal nephron from type 1 diabetic rats.

    Directory of Open Access Journals (Sweden)

    Eduardo Molina-Jijón

    Full Text Available Hyperglycemia in diabetes alters tight junction (TJ proteins in the kidney. We evaluated the participation of aldosterone (ALD, and the effect of spironolactone (SPL, a mineralocorticoid receptor antagonist, on the expressions of claudin-2, -4, -5 and -8, and occludin in glomeruli, proximal and distal tubules isolated from diabetic rats. Type 1 diabetes was induced in female Wistar rats by a single tail vein injection of streptozotocin (STZ, and SPL was administrated daily by gavage, from days 3-21. Twenty-one days after STZ injection the rats were sacrificed. In diabetic rats, the serum ALD levels were increased, and SPL-treatment did not have effect on these levels or in hyperglycemia, however, proteinuria decreased in SPL-treated diabetic rats. Glomerular damage, evaluated by nephrin and Wilm's tumor 1 (WT1 protein expressions, and proximal tubular damage, evaluated by kidney injury molecule 1 (Kim-1 and heat shock protein 72 kDa (Hsp72 expressions, were ameliorated by SPL. Also, SPL prevented decrement in claudin-5 in glomeruli, and claudin-2 and occludin in proximal tubules by decreasing oxidative stress, evaluated by superoxide anion (O2●- production, and oxidative stress markers. In distal tubules, SPL ameliorated increase in mRNA, protein expression, and phosphorylation in threonine residues of claudin-4 and -8, through a serum and glucocorticoid-induced kinase 1 (SGK1, and with-no-lysine kinase 4 (WNK4 signaling pathway. In conclusion, this is the first study that demonstrates that ALD modulates the expression of renal TJ proteins in diabetes, and that the blockade of its actions with SPL, may be a promising therapeutic strategy to prevent alterations of TJ proteins in diabetic nephropathy.

  2. Direct physical contact between intercalated cells in the distal convoluted tubule and the afferent arteriole in mouse kidneys.

    Directory of Open Access Journals (Sweden)

    Hao Ren

    Full Text Available Recent physiological studies in the kidney proposed the existence of a secondary feedback mechanism termed 'crosstalk' localized after the macula densa. This newly discovered crosstalk contact between the nephron tubule and its own afferent arteriole may potentially revolutionize our understanding of renal vascular resistance and electrolyte regulation. However, the nature of such a crosstalk mechanism is still debated due to a lack of direct and comprehensive morphological evidence. Its exact location along the nephron, its prevalence among the different types of nephrons, and the type of cells involved are yet unknown. To address these issues, computer assisted 3-dimensional nephron tracing was applied in combination with direct immunohistochemistry on plastic sections and electron microscopy. 'Random' contacts in the cortex were identified by the tracing and excluded. We investigated a total of 168 nephrons from all cortical regions. The results demonstrated that the crosstalk contact existed, and that it was only present in certain nephrons (90% of the short-looped and 75% of the long-looped nephrons. The crosstalk contacts always occurred at a specific position--the last 10% of the distal convoluted tubule. Importantly, we demonstrated, for the first time, that the cells found in the tubule wall at the contact site were always type nonA-nonB intercalated cells. In conclusion, the present work confirmed the existence of a post macula densa physical crosstalk contact.

  3. Direct physical contact between intercalated cells in the distal convoluted tubule and the afferent arteriole in mouse kidneys.

    Science.gov (United States)

    Ren, Hao; Liu, Ning-Yu; Andreasen, Arne; Thomsen, Jesper S; Cao, Liu; Christensen, Erik I; Zhai, Xiao-Yue

    2013-01-01

    Recent physiological studies in the kidney proposed the existence of a secondary feedback mechanism termed 'crosstalk' localized after the macula densa. This newly discovered crosstalk contact between the nephron tubule and its own afferent arteriole may potentially revolutionize our understanding of renal vascular resistance and electrolyte regulation. However, the nature of such a crosstalk mechanism is still debated due to a lack of direct and comprehensive morphological evidence. Its exact location along the nephron, its prevalence among the different types of nephrons, and the type of cells involved are yet unknown. To address these issues, computer assisted 3-dimensional nephron tracing was applied in combination with direct immunohistochemistry on plastic sections and electron microscopy. 'Random' contacts in the cortex were identified by the tracing and excluded. We investigated a total of 168 nephrons from all cortical regions. The results demonstrated that the crosstalk contact existed, and that it was only present in certain nephrons (90% of the short-looped and 75% of the long-looped nephrons). The crosstalk contacts always occurred at a specific position--the last 10% of the distal convoluted tubule. Importantly, we demonstrated, for the first time, that the cells found in the tubule wall at the contact site were always type nonA-nonB intercalated cells. In conclusion, the present work confirmed the existence of a post macula densa physical crosstalk contact.

  4. Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis Following Segmental Posterior Spinal Instrumentation and Fusion; Minimum 2 Years Follow-Up

    Directory of Open Access Journals (Sweden)

    Mohammad Khaki Nahad

    2009-11-01

    Full Text Available Background:To evaluate proximal junctional segment changes in Adolescent Idiopathic Scoliosis(AIS the posterior spinal fusion and also instrumentation also and finding of probable risk factors, were all considered in this study.Methods: We retrospectively reviewed radiographs of 121 consecutive patients who underwent posterior spinal fusion for AIS from T3 or below, with a mean follow-   up of 32.8 months(range,24-83. All coronal and sagittal measurements including the proximal junctional kyphosis (PJKangle recorded on standing anteroposterior and lateral radiographs preoperative, early postoperative and on follow-up radiographs.The data were analyzed using the Spss 10.0 software.Dependent(paired samples student t-test was used for analysis between the groups Results: There was PJK angle above normal for the same junctional segment preoperatively in 13 patients (10.7% and the incidence of the PJK postoperatively was   7.4% (9 patients, 7 female and 2 male, all detected until 2 years postoperation.The mean increase in the PJK angle from pre-operation until 6 weeks postoperation was 5.9° (range,0-13°(P=0.02 and until 2 years post operation was 14.3° (range, 2- 16°(p=0.000.The mean proximal junctional angle increased 1.6° until 2 years postoperation in non-PJK group(n=112.Conclusion: The prevalence of Proximal Junctional Kyphosis was low and a silent radiographic problem. In some cases is preventable with perfect pre-operative planning. There is no specific demographic or radiographic variables or instrumentation types associated with developing PJK .

  5. Proximity credentials: A survey

    International Nuclear Information System (INIS)

    Wright, L.J.

    1987-04-01

    Credentials as a means of identifying individuals have traditionally been a photo badge and more recently, the coded credential. Another type of badge, the proximity credential, is making inroads in the personnel identification field. This badge can be read from a distance instead of being veiewed by a guard or inserted into a reading device. This report reviews proximity credentials, identifies the companies marketing or developing proximity credentials, and describes their respective credentials. 3 tabs

  6. Calcineurin inhibitor-induced complement system activation via ERK1/2 signalling is inhibited by SOCS-3 in human renal tubule cells.

    Science.gov (United States)

    Loeschenberger, Beatrix; Niess, Lea; Würzner, Reinhard; Schwelberger, Hubert; Eder, Iris E; Puhr, Martin; Guenther, Julia; Troppmair, Jakob; Rudnicki, Michael; Neuwirt, Hannes

    2018-02-01

    One factor that significantly contributes to renal allograft loss is chronic calcineurin inhibitor (CNI) nephrotoxicity (CIN). Among other factors, the complement (C-) system has been proposed to be involved CIN development. Hence, we investigated the impact of CNIs on intracellular signalling and the effects on the C-system in human renal tubule cells. In a qPCR array, CNI treatment upregulated C-factors and downregulated SOCS-3 and the complement inhibitors CD46 and CD55. Additionally, ERK1/-2 was required for these regulations. Following knock-down and overexpression of SOCS-3, we found that SOCS-3 inhibits ERK1/-2 signalling. Finally, we assessed terminal complement complex formation, cell viability and apoptosis. Terminal complement complex formation was induced by CNIs. Cell viability was significantly decreased, whereas apoptosis was increased. Both effects were reversed under complement component-depleted conditions. In vivo, increased ERK1/-2 phosphorylation and SOCS-3 downregulation were observed at the time of transplantation in renal allograft patients who developed a progressive decline of renal function in the follow-up compared to stable patients. The progressive cohort also had lower total C3 levels, suggesting higher complement activity at baseline. In conclusion, our data suggest that SOCS-3 inhibits CNI-induced ERK1/-2 signalling, thereby blunting the negative control of C-system activation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    Directory of Open Access Journals (Sweden)

    Manoocher Soleimani

    Full Text Available Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2 and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2 in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of

  8. Megalin is a receptor for apolipoprotein M, and kidney-specific megalin-deficiency confers urinary excretion of apolipoprotein M

    DEFF Research Database (Denmark)

    Faber, Kirsten; Hvidberg, Vibeke; Moestrup, Søren K

    2006-01-01

    . In addition, apoM is expressed at high levels in the kidney tubule cells. In this study, we show that the multiligand receptor megalin, which is expressed in kidney proximal tubule cells, is a receptor for apoM and mediates its uptake in the kidney. To examine apoM binding to megalin, a recombinant apo....... To examine the importance of apoM binding by megalin in vivo, we analyzed mice with a tissue-specific deficiency of megalin in the kidney. Megalin deficiency was associated with pronounced urinary excretion of apoM, whereas apoM was not detected in normal mouse, human, or rat urine. Gel filtration analysis...... showed that the urinary apoM-containing particles were small and devoid of apoA-I. The results suggest that apoM binds to megalin and that megalin-mediated endocytosis in kidney proximal tubules prevents apoM excretion in the urine....

  9. Endomedullar nail of metacarpal and proximal phalanges

    International Nuclear Information System (INIS)

    Mendez Olaya, Francisco Javier; Sanchez Mesa, Pedro Antonio

    2002-01-01

    Prospective study, series of cases; it included patients with diaphysis fractures and union diaphysis-neck or union diaphysis-base of metacarpal and proximal phalanges, in whom was practiced anterograde intramedullary nailing previous closed reduction of the fracture, using prevent intramedullary nail of 1.6 mm. (cem 16) for the metacarpal fractures, and two nail prevent of 1.0 mm. (cem 10) for the proximal phalangeal fractures. Indications: transverse and oblique short fractures, spiral and with comminuting bicortical. Pursuit average is 5.7 months. Frequency surgical intervened patient: 2.2 each month, using this surgical technique a total of 20 (twenty) patients have been operated, 21 (twenty one) fractures; 16 (sixteen) metacarcal fractures and 5 (five) proximal phalangeal fractures, all of them tested using clinical and radiological parameters. Results: good 82%, regular 18%, and bad 0% obtaining bony consolidation and early rehabilitation with incorporation to their habitual works

  10. The adult Drosophila malphigian tubules are maintained by multipotent stem cells | Center for Cancer Research

    Science.gov (United States)

    All animals must excrete the waste products of metabolism. Excretion is performed by the kidney in vertebrates and by the Malpighian tubules in Drosophila. The mammalian kidney has an inherent ability for recovery and regeneration after ischemic injury. Stem cells and progenitor cells have been proposed to be responsible for repair and regeneration of injured renal tissue.

  11. Protective Effect of Urtica dioica L. (Urticaceae) on Morphometric and Morphologic Alterations of Seminiferous Tubules in STZ Diabetic Rats.

    Science.gov (United States)

    Golalipour, Mohammad Jafar; Kabiri Balajadeh, Babak; Ghafari, Soraya; Azarhosh, Ramin; Khori, Vahid

    2011-09-01

    Urtica dioica L. has been known as a medicinal plant in the world. This study was conducted to determine the effects of the hydroalcoholic extract of Urtica dioica leaves on seminiferous tubules of diabetic rats. Animals were allocated to control, diabetic and protective groups. Treated animals received extract of U. dioica (100 mg/ kg/ day) IP for the first 5 days and STZ injection on the 6th day. After 5 weeks, testes removed and stained with H&E technique. Tubular cell disintegration, sertoli and spermatogonia cell vacuolization, and decrease in sperm concentration observed in diabetic in comparison with control and protective groups. External seminiferous tubular diameter and seminiferous epithelial height significantly reduced (Pdioica, before induction of diabetes; has protective role on seminiferous tubules alterations.

  12. Autoradiographic localization of Na+-K+-ATPase with 3H-ouabain

    International Nuclear Information System (INIS)

    Dormans, J.A.M.A.

    1976-01-01

    Using 3 H-ouabain as an inhibitor, the site of the Na + -K + -ATPase system in cells was determined autoradiographically. Experiments were performed woth guinea pig's kidney tissue. The application of light microscopical autoradiography to freeze-dried tissue showed that especially the distal tubule, and to a smaller extent the proximal tubule and the collecting tubule have Na + -K + -ATPase. Electron microscopical autoradiography showed that this activity is restricted to the baso-lateral plasmamembranes. The quantity of specific bound ouabain turns out to be correlated to the quantity of baso-lateral plasmamembrane's surface

  13. Use systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    Directory of Open Access Journals (Sweden)

    Yasong eLu

    2014-12-01

    Full Text Available In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1 and 2 (SGLT2 along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80% of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al. data (2013, and evaluated against clinical data from the literature (Mogensen, 1971;Wolf et al., 2009;Polidori et al., 2013. The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to

  14. Dual pathology proximal median nerve compression of the forearm.

    LENUS (Irish Health Repository)

    Murphy, Siun M

    2013-12-01

    We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref. 3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression.

  15. Na+ Recirculation and Isosmotic Transport

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Møbjerg, N

    2006-01-01

    of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability...... in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal Na...... external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and

  16. Effect of Tamoxifen on Seminiferous Tubules Structure during Pregnancy in Adult Mice

    Directory of Open Access Journals (Sweden)

    J Soleimani Rad

    2016-03-01

    Full Text Available Introduction: Tamoxifen is a nonsteroidal drug which mainly treats breast cancer. It is also applied for stimulation of ovulation and remedy of infertility. Regarding the tamoxifen binding to estrogen receptors and the possible role of estrogens in spermatogenesis, the present study aimed to histologically evaluate spermatogenesis in the seminiferous ducts of mice, whose mothers had received tamoxifen during pregnancy. Methods: In the present study, 30 female and 15 male mice of NMRI race were selected for mating. Since 13th day of pregnancy, the experimental group received tamoxifen with the dosage of 5 mg/kg intra-peritoneally for 7 days, wherease the control group received normal saline. After childbirth of the mated mice, male infants were selected and monitored in the standard laboratory conditions. After reaching the age of puberty (6-8Weeks, adult mice were sacrificed by the cervical dislocation, and the testes were removed for histological evaluation of spermatogenesis. After routine histological processing, the samples were studied by the light microscope. Results: Histological studies showed that spermatogenic and Sertoli cells in the seminiferous tubules in control and experimental groups were significantly different, though no difference was observed in the number of Leydig cells in the both groups. Conclusion: The findings of the present study showed that tamoxifen exposure during development can cause histological changes in the seminiferous tubules, which can lead to infertility in the male rat.

  17. A proximal point algorithm with generalized proximal distances to BEPs

    OpenAIRE

    Bento, G. C.; Neto, J. X. Cruz; Lopes, J. O.; Soares Jr, P. A.; Soubeyran, A.

    2014-01-01

    We consider a bilevel problem involving two monotone equilibrium bifunctions and we show that this problem can be solved by a proximal point method with generalized proximal distances. We propose a framework for the convergence analysis of the sequences generated by the algorithm. This class of problems is very interesting because it covers mathematical programs and optimization problems under equilibrium constraints. As an application, we consider the problem of the stability and change dyna...

  18. Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods

    OpenAIRE

    Vatkar, Niranjan Ashok; Hegde, Vivek; Sathe, Sucheta

    2016-01-01

    Aim: To compare the vitality of Enterococcus faecalis within dentinal tubules after subjected to five root canal disinfection methods. Materials and Methods: Dentin blocks (n = 60) were colonized with E. faecalis. After 4 weeks of incubation, the dentin blocks were divided into one control and five test groups (n = 10 each). The root canals of test groups were subjected to one of the disinfection methods, namely, normal saline (NS), sodium hypochlorite (NaOCl), chlorhexidine digluconate (C...

  19. RNA-Seq Comparison of Larval and Adult Malpighian Tubules of the Yellow Fever Mosquito Aedes aegypti Reveals Life Stage-Specific Changes in Renal Function

    Directory of Open Access Journals (Sweden)

    Yiyi Li

    2017-05-01

    Full Text Available Introduction: The life history of Aedes aegypti presents diverse challenges to its diuretic system. During the larval and pupal life stages mosquitoes are aquatic. With the emergence of the adult they become terrestrial. This shifts the organism within minutes from an aquatic environment to a terrestrial environment where dehydration has to be avoided. In addition, female mosquitoes take large blood meals, which present an entirely new set of challenges to salt and water homeostasis.Methods: To determine differences in gene expression associated with these different life stages, we performed an RNA-seq analysis of the main diuretic tissue in A. aegypti, the Malpighian tubules. We compared transcript abundance in 4th instar larvae to that of adult females and analyzed the data with a focus on transcripts that encode proteins potentially involved in diuresis, like water and solute channels as well as ion transporters. We compared our results against the model of potassium- and sodium chloride excretion in the Malpighian tubules proposed by Hine et al. (2014, which involves at least eight ion transporters and a proton-pump.Results: We found 3,421 of a total number of 17,478 (19.6% unique transcripts with a P < 0.05 and at least a 2.5 fold change in expression levels between the two groups. We identified two novel transporter genes that are highly expressed in the adult Malpighian tubules, which have not previously been part of the transport model in this species and may play important roles in diuresis. We also identified candidates for hypothesized sodium and chloride channels. Detoxification genes were generally higher expressed in larvae.Significance: This study represents the first comparison of Malpighian tubule transcriptomes between larval and adult A. aegypti mosquitoes, highlighting key differences in their renal systems that arise as they transform from an aquatic filter-feeding larval stage to a terrestrial, blood-feeding adult stage.

  20. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3

    Energy Technology Data Exchange (ETDEWEB)

    Malinouski, M.; Kehr, S.; Finney, L.; Vogt, S.; Carlson, B.A.; Seravalli, J.; Jin, R.; Handy, D.E.; Park, T.J.; Loscalzo, J.; Hatfield, D.L.; Gladyshev, V.N. (Harvard-Med)

    2012-04-17

    Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA{sup [Ser]Sec} and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.

  1. HEMATOMA OF THE PROXIMAL NAIL FOLD. REPORT OF 41 CASES

    Directory of Open Access Journals (Sweden)

    Chang Patricia

    2011-04-01

    Full Text Available Background: The proximal fold is an important part of the nail apparatus it contributes to the formation of the nail plate and through the cuticle acts as an impermeable barrier protecting it from any cause.Objective: To know the proximal nail fold hematoma caused by the use of pulse oximeter.Material and Methods: A descriptive study was conducted in 41 patients with proximal nail hematoma secondary to the use of oximetry in patients hospitalized in the Intermediate and Intensive Care Unit at the Hospital General de Enfermedades from December 1, 2007 to December 31, 2010.Results: We studied 41 patients with proximal nail fold hematoma secondary to the use of oximeter, 30 (73.1% were males and 11 (26.8% females. The numbers of fingers affected by pulse oximeter were in one digit. 30 (73.1% cases, in two digits 6 (14.6%, in three digits 3 (7.3%, in 4 digits 1 (2.4% and in 5 digits 1 (2.4% case. The most affected proximal nail fold was right index: 24 (58.5%, right middle 11 (26.8%, right ring 6 (14.6%, left index 12 (29.2%, and left middle 6 (14.6% cases.Conclusions: Hematomas of the proximal nail fold may be caused by different traumatisms. The use of pulse oximeter is one of them.

  2. Effects of Hyperbaric Oxygen Treatment on Renal System.

    Science.gov (United States)

    Tezcan, Orhan; Caliskan, Ahmet; Demirtas, Sinan; Yavuz, Celal; Kuyumcu, Mahir; Nergiz, Yusuf; Guzel, Abdulmenap; Karahan, Oguz; Ari, Seyhmus; Soker, Sevda; Yalinkilic, Ibrahim; Turkdogan, Kenan Ahmet

    2017-01-01

    Hyperbaric oxygen (HBO) treatment is steadily increasing as a therapeutic modality for various types of diseases. Although good clinical outcomes were reported with HBO treatment for various diseases, the multisystemic effects of this modality are still unclear. This study aimed to investigate the renal effects of HBO experimentally. Fourteen New Zealand White rabbits were divided into 2 groups randomly as the control group and the study group. The study group received HBO treatment for 28 days (100% oxygen at 2.5 atmospheres for 90 minutes daily) and the control group was used to obtain normal renal tissue of the animal genus. After the intervention period, venous blood samples were obtained, and renal tissue samples were harvested for comparisons. Normal histological morphology was determined with Masson trichrome staining and periodic acid-Schiff staining in the control group. Atrophic glomerular structures, vacuolated tubule cells, and degeneration were detected in the renal samples of the study group with Masson trichrome staining. Additionally, flattening was observed on the brush borders of the proximal tubules, and tubular dilatation was visualized with periodic acid-Schiff staining. The histopathologic disruption of renal morphology was verified with detection of significantly elevated kidney function laboratory biomarkers in the study group. Our findings suggests that HBO has adverse effects on renal glomerulus and proximal tubules. However, the functional effects of this alteration should be investigated with further studies.

  3. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    Science.gov (United States)

    Lu, Yasong; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30–50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30–50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2

  4. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans.

    Science.gov (United States)

    Lu, Yasong; Griffen, Steven C; Boulton, David W; Leil, Tarek A

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2 modulation.

  5. Nifedipine-activated Ca(2+) permeability in newborn rat cortical collecting duct cells in primary culture.

    Science.gov (United States)

    Valencia, L; Bidet, M; Martial, S; Sanchez, E; Melendez, E; Tauc, M; Poujeol, C; Martin, D; Namorado, M D; Reyes, J L; Poujeol, P

    2001-05-01

    To characterize Ca(2+) transport in newborn rat cortical collecting duct (CCD) cells, we used nifedipine, which in adult rat distal tubules inhibits the intracellular Ca(2+) concentration ([Ca(2+)](i)) increase in response to hormonal activation. We found that the dihydropyridine (DHP) nifedipine (20 microM) produced an increase in [Ca(2+)](i) from 87.6 +/- 3.3 nM to 389.9 +/- 29.0 nM in 65% of the cells. Similar effects of other DHP (BAY K 8644, isradipine) were also observed. Conversely, DHPs did not induce any increase in [Ca(2+)](i) in cells obtained from proximal convoluted tubule. In CCD cells, neither verapamil nor diltiazem induced any rise in [Ca(2+)](i). Experiments in the presence of EGTA showed that external Ca(2+) was required for the nifedipine effect, while lanthanum (20 microM), gadolinium (100 microM), and diltiazem (20 microM) inhibited the effect. Experiments done in the presence of valinomycin resulted in the same nifedipine effect, showing that K(+) channels were not involved in the nifedipine-induced [Ca(2+)](i) rise. H(2)O(2) also triggered [Ca(2+)](i) rise. However, nifedipine-induced [Ca(2+)](i) increase was not affected by protamine. In conclusion, the present results indicate that 1) primary cultures of cells from terminal nephron of newborn rats are a useful tool for investigating Ca(2+) transport mechanisms during growth, and 2) newborn rat CCD cells in primary culture exhibit a new apical nifedipine-activated Ca(2+) channel of capacitive type (either transient receptor potential or leak channel).

  6. Protective Effects of Pistacia lentiscus L. fruit extract against calcium oxalate monohydrate induced proximal tubular injury.

    Science.gov (United States)

    Cheraft-Bahloul, Nassima; Husson, Cécile; Ourtioualous, Meriam; Sinaeve, Sébastien; Atmani, Djebbar; Stévigny, Caroline; Nortier, Joëlle L; Antoine, Marie-Hélène

    2017-09-14

    The world prevalence of kidney stones is increasing and plants are frequently used to treat urolithiasis. Pistacia lentiscus L, a plant which freely grows around the Mediterranean basin areas, is widely used for various pathologies. P. lentiscus has an important impact as it has economical value on top of its pharmacological interest. Decoctions of its aerial parts and/or resin are used to treat kidney stones. To in vitro assess the potential nephroprotective effect of Pistacia lentiscus ethanolic fruit extract (PLEF) on proximal tubular cells in response to the adhesion of calcium oxalate monohydrate (COM) crystals. Human Kidney [HK]-2 cells were incubated with and without COM in the presence or absence of PLEF. Cell viability was measured by the resazurin assay. The expression of E-cadherin was analyzed by PCR. The extracellular production of H 2 O 2 was measured by Amplex® Red H 2 O 2 Assay. The numbers of detached or non-adherent COM crystals in the presence of PLEF were microscopically captured and counted using ImageJ software. The interaction of PLEF with COM and the effect of PLEF on crystal size were analyzed by flow cytometry. The spectrophotometric measurement of turbidity was performed for assessing the COM concentration. PLEF incubated with COM was able to increase the cell viability. The decrease of E-cadherin expression after incubation with COM was counteracted by PLEF. Overproduction of H 2 O 2 induced by COM was also inhibited by PLEF. Observations using flow cytometry showed that interactions between PLEF and the COM crystals occurred. PLEF was also effective in reducing the particles size and in lowering COM concentration. Our data show that COM tubulotoxicity can be significantly reversed by PLEF -at least in part- via an inhibition of COM crystals adhesion onto the apical membrane. This early beneficial effect of PLEF needs to be further investigated as a useful strategy in nephrolithiasis prevention. Copyright © 2017 Elsevier Ireland Ltd

  7. Reducing αENaC expression in kidney connecting tubule induces pseudohypoaldosteronism type 1 symptoms during K+ loading

    DEFF Research Database (Denmark)

    Poulsen, Søren Brandt; Praetorius, Jeppe; Damkier, Helle H

    2015-01-01

    Genetic inactivation of the epithelial Na(+) channel α-subunit (αENaC) in the renal collecting duct (CD) does not interfere with Na(+) and K(+) homeostasis in mice. However, inactivation in the CD and a part of the connecting tubule (CNT) induces autosomal recessive pseudohypoaldosteronism type 1...

  8. GPI Spectra of HR8799 C, D, and E in H-K Bands with KLIP Forward Modeling

    Science.gov (United States)

    Greenbaum, Alexandra Z.; Pueyo, Laurent; Ruffio, Jean-Baptiste; Wang, Jason J.; De Rosa, Robert J.; Aguilar, Jonathan; Rameau, Julien; Barman, Travis; Marois, Christian; Marley, Mark S.; hide

    2018-01-01

    We demonstrate KLIP forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR8799, using PyKLIP. We report new and re-reduced spectrophotometry of HR8799 c, d, and e from H-K bands. We discuss a strategy for choosing optimal KLIP PSF subtraction parameters by injecting fake sources and recovering them over a range of parameters. The K1/K2 spectra for planets c and d are similar to previously published results from the same dataset. We also present a K band spectrum of HR8799e for the first time and show that our H-band spectra agree well with previously published spectra from the VLT/SPHERE instrument. We compare planets c, d, and e with M, L, and T-type field objects. All objects are consistent with low gravity mid-to-late L dwarfs, however, a lack of standard spectra for low gravity late L-type objects lead to poor fit for gravity. We place our results in context of atmospheric models presented in previous publications and discuss differences in the spectra of the three planets.

  9. Dual pathology proximal median nerve compression of the forearm.

    Science.gov (United States)

    Murphy, Siun M; Browne, Katherine; Tuite, David J; O'Shaughnessy, Michael

    2013-12-01

    We report an unusual case of synchronous pathology in the forearm- the coexistence of a large lipoma of the median nerve together with an osteochondroma of the proximal ulna, giving rise to a dual proximal median nerve compression. Proximal median nerve compression neuropathies in the forearm are uncommon compared to the prevalence of distal compression neuropathies (eg Carpal Tunnel Syndrome). Both neural fibrolipomas (Refs. 1,2) and osteochondromas of the proximal ulna (Ref. 3) in isolation are rare but well documented. Unlike that of a distal compression, a proximal compression of the median nerve will often have a definite cause. Neural fibrolipoma, also called fibrolipomatous hamartoma are rare, slow-growing, benign tumours of peripheral nerves, most often occurring in the median nerve of younger patients. To our knowledge, this is the first report of such dual pathology in the same forearm, giving rise to a severe proximal compression of the median nerve. In this case, the nerve was being pushed anteriorly by the osteochondroma, and was being compressed from within by the intraneural lipoma. This unusual case highlights the advantage of preoperative imaging as part of the workup of proximal median nerve compression. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. An elastic network model of HK97 capsid maturation.

    Science.gov (United States)

    Kim, Moon K; Jernigan, Robert L; Chirikjian, Gregory S

    2003-08-01

    The structure of the capsid of bacteriophage HK97 has been solved at various stages of maturity by crystallography and cryo-electron microscopy, and has been reported previously in the literature. Typically the capsid assembles through polymerization and maturation processes. Maturation is composed of proteolytic cleavages to the precursor capsid (called Prohead II), expansion triggered by DNA packaging (in which the largest conformational changes of the capsid appear), and covalent cross-links of neighboring subunits to create the mature capsid called Head II. We apply a coarse-grained elastic network interpolation (ENI) to generate a feasible pathway for conformational change from Prohead II to Head II. The icosahedral symmetry of the capsid structure offers a significant computational advantage because it is not necessary to consider the whole capsid structure but only an asymmetric unit consisting of one hexamer plus an additional subunit from an adjacent pentamer. We also analyze normal modes of the capsid structure using an elastic network model which is also subject to symmetry constraints. Using our model, we can visualize the smooth evolution of capsid expansion and revisit in more detail several interesting geometric changes recognized in early experimental works such as rigid body motion of two compact domains (A and P) with two refolding extensions (N-arm and E-loop) and track the approach of the two particular residues associated with isopeptide bonds that make hexagonal cross-links in Head II. The feasibility of the predicted pathway is also supported by the results of our normal mode analysis.

  11. Plasticity of the transverse tubules following denervation and subsequent reinnervation in rat slow and fast muscle fibres.

    Science.gov (United States)

    Takekura, Hiroaki; Tamaki, Hiroyuki; Nishizawa, Tomie; Kasuga, Norikatsu

    2003-01-01

    We have studied the effects of short term denervation followed by reinnervation on the ultrastructure of the membrane systems and on the content of and distribution of key proteins involved in calcium regulation of fast-twitch (FT) extensor digitorum longus (EDL) and slow-twitch (ST) soleus (SOL) muscle fibres. Ischiadic nerve freezing resulted in total lack of neuromuscular transmission for 3 days followed by a slow recovery, but no decline in twitch force elicited by direct stimulation. The latter measurements indicate no significant atrophy within this time frame. The membrane systems of skeletal muscle fibres were visualized using Ca92+)-K3Fe(CN)6-OsO4 techniques and observed using a high voltage electron microscope. [3H]nitrendipine binding was used to detect levels of dihydropyridine receptor (DHPR) expression. The Ca2+ pumping free sarcoplasmic reticulum domains were not affected by the denervation, but the Ca2+ release domains were dramatically increased, particularly in the FT-EDL muscle fibres. The increase is evidenced by a doubling up of the areas of contacts between SR and transverse (t-) tubules, so that in place of the normal triadic arrangement, pentadic and heptadic junctions, formed by multiple interacting layers of ST and t-tubules are seen. Frequency of pentads and heptads increases and declines in parallel to the denervation and reinnervation but with a delay. Immunofluorecence and electron microscopy observations show presence of DHPR and ryanodine receptor clusters at pentads and heptads junctions. A significant (P muscle fibres indicating that overexpression of DHPRs accompanies the build up extra junctional contacts. The results indicate that denervation reversibly affects the domains of the membrane systems involved in excitation-contraction coupling.

  12. Network-Assisted Device-to-Device (D2D) Direct Proximity Discovery with Underlay Communication

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar

    2015-01-01

    ) direct communication between proximate devices. While (ii) is treated extensively in the recent literature, (i) has received relatively little attention. In this paper we analyze a network-assisted underlay proximity discovery protocol, where a cellular device can take the role of: announcer (which......Device-to-Device communications are expected to play an important role in current and future cellular generations, by increasing the spatial reuse of spectrum resources and enabling lower latency communication links. This paradigm has two fundamental building blocks: (i) proximity discovery and (ii......, we consider the case where the announcers underlay their messages in the downlink transmissions that are directed towards the monitoring devices. We propose a power control scheme applied to the downlink transmission, which copes with the underlay transmission via additional power expenditure, while...

  13. The supposedly attenuated Hy-HK variant of highly virulent Hypr strain of Tick-borne encephalitis virus is obviously a strain of Langat virus

    Czech Academy of Sciences Publication Activity Database

    Růžek, Daniel; Štěrba, Ján; Kopecký, Jan; Grubhoffer, Libor

    2006-01-01

    Roč. 50, č. 4 (2006), s. 277-278 ISSN 0001-723X R&D Projects: GA ČR(CZ) GA524/06/1479 Grant - others:Grant Agency of the University of South Bohemia(CZ) 35/2005/P-BF Institutional research plan: CEZ:AV0Z60220518 Keywords : TBE virus * Langat virus * Hy-HK attenuated variant Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.788, year: 2006

  14. Effect of water on self-assembled tubules in β-sitosterol + γ-oryzanol-based organogels

    Science.gov (United States)

    den Adel, Ruud; Heussen, Patricia C. M.; Bot, Arjen

    2010-10-01

    Mixtures of β-sitosterol and γ-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. β-Sitosterol and γ-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of β-sitosterol + γ-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of β-sitosterol + γ-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2±0.1 nm, wall thickness 0.8±0.2 nm).

  15. Effect of water on self-assembled tubules in {beta}-sitosterol + {gamma}-oryzanol-based organogels

    Energy Technology Data Exchange (ETDEWEB)

    Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen, E-mail: ruud-den.adel@unilever.co [Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, NL-3133 AT Vlaardingen (Netherlands)

    2010-10-01

    Mixtures of {beta}-sitosterol and {gamma}-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. {beta}-Sitosterol and {gamma}-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of {beta}-sitosterol + {gamma}-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of {beta}-sitosterol + {gamma}-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2{+-}0.1 nm, wall thickness 0.8{+-}0.2 nm).

  16. Effect of water on self-assembled tubules in β-sitosterol + γ-oryzanol-based organogels

    International Nuclear Information System (INIS)

    Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen

    2010-01-01

    Mixtures of β-sitosterol and γ-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. β-Sitosterol and γ-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of β-sitosterol + γ-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of β-sitosterol + γ-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2±0.1 nm, wall thickness 0.8±0.2 nm).

  17. MiR-30c regulates cisplatin-induced apoptosis of renal tubular epithelial cells by targeting Bnip3L and Hspa5.

    Science.gov (United States)

    Du, Bin; Dai, Xiao-Meng; Li, Shuang; Qi, Guo-Long; Cao, Guang-Xu; Zhong, Ying; Yin, Pei-di; Yang, Xue-Song

    2017-08-10

    As a common anticancer drug, cisplatin has been widely used for treating tumors in the clinic. However, its side effects, especially its nephrotoxicity, noticeably restrict the application of cisplatin. Therefore, it is imperative to investigate the mechanism of renal injury and explore the corresponding remedies. In this study, we showed the phenotypes of the renal tubules and epithelial cell death as well as elevated cleaved-caspase3- and TUNEL-positive cells in rats intraperitoneally injected with cisplatin. Similar cisplatin-induced cell apoptosis was found in HK-2 and NRK-52E cells exposed to cisplatin as well. In both models of cisplatin-induced apoptosis in vivo and in vitro, quantitative PCR data displayed reductions in miR-30a-e expression levels, indicating that miR-30 might be involved in regulating cisplatin-induced cell apoptosis. This was further confirmed when the effects of cisplatin-induced cell apoptosis were found to be closely correlated with alterations in miR-30c expression, which were manipulated by transfection of either the miR-30c mimic or miR-30c inhibitor in HK-2 and NRK-52E cells. Using bioinformatics tools, including TargetScan and a gene expression database (Gene Expression Omnibus), Adrb1, Bnip3L, Hspa5 and MAP3K12 were predicted to be putative target genes of miR-30c in cisplatin-induced apoptosis. Subsequently, Bnip3L and Hspa5 were confirmed to be the target genes after determining the expression of these putative genes following manipulation of miR-30c expression levels in HK-2 cells. Taken together, our current experiments reveal that miR-30c is certainly involved in regulating the renal tubular cell apoptosis induced by cisplatin, which might supply a new strategy to minimize cisplatin-induced nephrotoxicity.

  18. [Mechanism of renal elimination of 2 elements of group IIIA of the periodic table : aluminum and indium].

    Science.gov (United States)

    Galle, P

    1981-01-05

    Aluminium and indium, two elements of group IIIA of the periodic table, are concentrated by the kidney inside lysosomes of proximal tubule cell. In these lysosomes, aluminium and indium are precipitated as non-soluble phosphate salts and these precipitates are then expelled in the tubular lumen and eliminated with the urinary flow. These data have been visualized by analytical microscopy (ion microscopy and X ray microanalysis). Local acid phosphatases are assumed to permit the concentration of aluminium and indium salts inside the lysosomes.

  19. A survey of HK, HPt, and RR domains and their organization in two-component systems and phosphorelay proteins of organisms with fully sequenced genomes

    Directory of Open Access Journals (Sweden)

    Baldiri Salvado

    2015-08-01

    Full Text Available Two Component Systems and Phosphorelays (TCS/PR are environmental signal transduction cascades in prokaryotes and, less frequently, in eukaryotes. The internal domain organization of proteins and the topology of TCS/PR cascades play an important role in shaping the responses of the circuits. It is thus important to maintain updated censuses of TCS/PR proteins in order to identify the various topologies used by nature and enable a systematic study of the dynamics associated with those topologies. To create such a census, we analyzed the proteomes of 7,609 organisms from all domains of life with fully sequenced and annotated genomes. To begin, we survey each proteome searching for proteins containing domains that are associated with internal signal transmission within TCS/PR: Histidine Kinase (HK, Response Regulator (RR and Histidine Phosphotranfer (HPt domains, and analyze how these domains are arranged in the individual proteins. Then, we find all types of operon organization and calculate how much more likely are proteins that contain TCS/PR domains to be coded by neighboring genes than one would expect from the genome background of each organism. Finally, we analyze if the fusion of domains into single TCS/PR proteins is more frequently observed than one might expect from the background of each proteome. We find 50 alternative ways in which the HK, HPt, and RR domains are observed to organize into single proteins. In prokaryotes, TCS/PR coding genes tend to be clustered in operons. 90% of all proteins identified in this study contain just one of the three domains, while 8% of the remaining proteins combine one copy of an HK, a RR, and/or an HPt domain. In eukaryotes, 25% of all TCS/PR proteins have more than one domain. These results might have implications for how signals are internally transmitted within TCS/PR cascades. These implications could explain the selection of the various designs in alternative circumstances.

  20. [Partial replantation following proximal limb injury].

    Science.gov (United States)

    Dubert, T; Malikov, S A; Dinh, A; Kupatadze, D D; Oberlin, C; Alnot, J Y; Nabokov, B B

    2000-11-01

    Proximal replantation is a technically feasible but life-threatening procedure. Indications must be restricted to patients in good condition with a good functional prognosis. The goal of replantation must be focused not only on reimplanting the amputated limb but also on achieving a good functional outcome. For the lower limb, simple terminalization remains the best choice in many cases. When a proximal amputation is not suitable for replantation, the main aim of the surgical procedure must be to reconstruct a stump long enough to permit fitting a prosthesis preserving the function of the adjacent joint. If the proximal stump beyond the last joint is very short, it may be possible to restore some length by partial replantation of spared tissues from the amputated part. We present here the results we obtained following this policy. This series included 16 cases of partial replantations, 14 involving the lower limb and 2 the upper limb. All were osteocutaneous microsurgical transfers. For the lower limb, all transfers recovered protective sensitivity following tibial nerve repair. The functional calcaeoplantar unit was used in 13 cases. The transfer of this specialized weight bearing tissue provided a stable distal surface making higher support unnecessary. In one case, we raised a 13-cm vascularized tibial segment covered with foot skin for additional length. For the upper limb, the osteocutaneous transfer, based on the radial artery, was not reinnervated, but this lack of sensitivity did not impair prosthesis fitting. One vascular failure was finally amputated. This was the only unsuccessful result. For all other patients, the surgical procedure facilitated prosthesis fitting and preserved the proximal joint function despite an initially very proximal amputation. The advantages of partial replantation are obvious compared with simple terminalization or secondary reconstruction. There is no secondary donor site and, because there is no major muscle mass in the

  1. A comparison of HK-CONWIP and BK-CONWIP control strategies in a multi-product manufacturing system

    Directory of Open Access Journals (Sweden)

    Chukwunonyelum Emmanuel Onyeocha

    2015-12-01

    Full Text Available This paper evaluates the performance of the Hybrid Kanban Constant Work-In-Process control strategy and Basestock Kanban Constant Work-In-Process control strategy operating Shared Kanban Allocation Policy (S-KAP and Dedicated Kanban Allocation Policy (D-KAP in a multi-product serial flow line. We explored the effect of an increase of product types on the WIP inventory in the system. A simulation-based optimisation technique was used in determining the optimal settings for the strategies. The strategies were compared via pairwise comparison technique and Nelson’s ranking and selection procedure. S-KAP responds quicker to demand than D-KAP. BK-CONWIP outperforms HK-CONWIP in a serial manufacturing system. It was shown that an increase in the number of product-type increases the number of PAC and WIP inventory.

  2. Proximally exposed A-bomb survivors. 2

    International Nuclear Information System (INIS)

    Kamada, Nanao

    1992-01-01

    Methods for observing chromosomes can be chronologically divided into the era of non-differential staining technique (1962-1975) and the era of differential staining method (since 1976). This paper reviews the literature of chromosomal aberrations in bone marrow cells found in the two eras. Findings during the era of 1962-1975 include the frequency of chromosomal aberrations in bone marrow cells, comparison of chromosomal aberrations in bone marrow cells and T lymphocytes, and annual variation of chromosomal aberrations. The frequency of chromosomal aberrations was high in proximally exposed A-bomb survivors (90.5% and 52.6% in A-bomb survivors exposed within 500 m and at 501-1,000 m, respectively); on the contrary, it was low in those exposed far from 1,000 m (6.2% or less). The frequency of chromosomal aberrations in bone marrow cells was lower than that in T lymphocytes (21.5% vs 27.1% in those exposed within 500 m and 14.1% vs 23% in those exposed at 501-1,000 m). Annual analysis for chromosomal aberrations has shown the somewhat dependence upon medullary hematopoiesis and virus infection. The advent of differential staining technique since 1976 has made it possible to clarify the type of chromosomal aberrations and site of breakage. Of 710 bone marrow cells taken from 13 A-bomb survivors exposed within 1,000 m, 121 cells (from 11 A-bomb survivors) exhibited chromosomal aberrations. In differential staining analysis, all 121 cells but one were found to be of stable type, such as translocation and inversion. Furthermore, the site of breakage was found to be non-randomly distributed. Analysis of chromosomal aberrations in bone marrow cells has advantages of reflecting dynamic condition of these cells and determining gradual progression into leukemia. (N.K.)

  3. Library of monoclonal antibodies against brush border membrane epithelial antigens

    International Nuclear Information System (INIS)

    Behar, M.; Katz, A.; Silverman, M.

    1986-01-01

    A purified fraction of proximal tubule brush border membranes (BBM) was prepared from dog kidney and used to immunize mice. The standard technique of hybridoma production was followed as described by Kohler and Milstein. Production of antibodies was detected by indirect immunofluorescence on dog kidney slices and by immunodot against the purified fraction on nitrocellulose. Five hybrids exhibited anti BBM activity. These were cloned twice and yielded stable cell lines producing IgG type monoclonal antibodies against BBM. They were designated A 1 , C 7 , D 3 , D 7 and H 4 . As a family these five monoclonals have broad tissue specificity, i.e. positive staining of the surface mucosa of intestinal kidney proximal tubules. D 3 exhibits even broader specificity for epithelium reacting with bile canaliculi and choroid plexus. The authors have verified that at least 4/5 antibodies are directed against BBM protein as revealed by immunoprecipitation of solubilized BBM and detected by Coomassie blue staining or autoradiography of lactoperoxidase labelled BBM. Most interestingly all antibodies bind to the surface of LL CPK 1 cells, a continuous pig kidney cell line of undefined origin but exhibiting many characteristics of proximal tubule cells. The library of monoclonal antibodies obtained provide important probes with which to study membrane biogenesis and polarization in epithelial cells

  4. Impaired Urine Dilution Capability in HIV Stable Patients

    Directory of Open Access Journals (Sweden)

    Waldo H. Belloso

    2014-01-01

    Full Text Available Renal disease is a well-recognized complication among patients with HIV infection. Viral infection itself and the use of some antiretroviral drugs contribute to this condition. The thick ascending limb of Henle’s loop (TALH is the tubule segment where free water clearance is generated, determining along with glomerular filtration rate the kidney’s ability to dilute urine. Objective. We analyzed the function of the proximal tubule and TALH in patients with HIV infection receiving or not tenofovir-containing antiretroviral treatment in comparison with healthy seronegative controls, by applying a tubular physiological test, hyposaline infusion test (Chaimowitz’ test. Material & Methods. Chaimowitz’ test was performed on 20 HIV positive volunteers who had normal renal functional parameters. The control group included 10 healthy volunteers. Results. After the test, both HIV groups had a significant reduction of serum sodium and osmolarity compared with the control group. Free water clearance was lower and urine osmolarity was higher in both HIV+ groups. Proximal tubular function was normal in both studied groups. Conclusion. The present study documented that proximal tubule sodium reabsorption was preserved while free water clearance and maximal urine dilution capability were reduced in stable HIV patients treated or not with tenofovir.

  5. Mechanism of phosphaturia elicited by administration of phosphonoformate in vivo

    International Nuclear Information System (INIS)

    VanScoy, M.; Loghman-Adham, M.; Onsgard, M.; Szczepanska-Konkel, M.; Homma, Sumiko; Knox, F.G.; Dousa, T.P.

    1988-01-01

    The authors examined whether phosphonoformate (PFA) can cause phosphaturia through its direct action on brush-border membrane (BBM) in vivo. Infusion of PFA or of parathyroid hormone (PTH) to thyroparathyroidectomized rats caused a marked increase in fractional excretion of phosphate without changes in excretion of Na + or of GFR. The PFA-induced phosphaturia was not accompanied by an increase in urinary adenosine-3',5'-cyclic monophosphate (cAMP); moreover, PFA added in vitro did not influence the PTH-sensitive adenylate cyclase and cAMP-phosphodiesterase in proximal convoluted tubules. In BBM vesicles (BBMV) from rats with PFA-elicited phosphaturia, neither the rate of Na + -P i symport nor Na + -dependent binding of [ 14 C]PFA on BBMV was changed, whereas in BBMV from PTH-infused rats the V max of Na + -P i symport decreased. PFA is almost completely ultrafiltrable; no metabolic transformation of PFA was detected after [ 14 C]PFA exposure to rat renal cortical slices, homogenate, or to blood. They conclude that PFA causes phosphaturia by direct inhibition of Na + -P i symport across BBM in proximal tubules, acting from the luminal side. Thus PFA (foscarnet) has a unique direct mechanism of phosphaturic effect, via its action on P i reabsorption in proximal tubules in vivo

  6. Treatment of Unstable Trochanteric Femur Fractures: Proximal Femur Nail Versus Proximal Femur Locking Compression Plate.

    Science.gov (United States)

    Singh, Ashutosh Kumar; Narsaria, Nidi; G R, Arun; Srivastava, Vivek

    Unstable trochanteric femur fractures are common fractures that are difficult to manage. We conducted a prospective study to compare functional outcomes and complications of 2 different implant designs, proximal femur nail (PFN) and proximal femur locking compression plate (PFLCP), used in internal fixation of unstable trochanteric femur fractures. On hospital admission, 48 patients with unstable trochanteric fractures were randomly assigned (using a sealed envelope method) to treatment with either PFN (24 patients) or PFLCP (24 patients). Perioperative data and complications were recorded. All cases were followed up for 2 years. The groups did not differ significantly (P > .05) in operative time, reduction quality, complications, hospital length of stay, union rate, or time to union. Compared with the PFLCP group, the PFN group had shorter incisions and less blood loss. Regarding functional outcomes, there was no significant difference in mean Harris Hip Score (P = .48) or Palmer and Parker mobility score (P = .58). Both PFN and PFLCP are effective in internal fixation of unstable trochanteric femur fractures.

  7. Caulimoviridae Tubule-Guided Transport Is Dictated by Movement Protein Properties ▿

    Science.gov (United States)

    Sánchez-Navarro, Jesús; Fajardo, Thor; Zicca, Stefania; Pallás, Vicente; Stavolone, Livia

    2010-01-01

    Plant viruses move through plasmodesmata (PD) either as nucleoprotein complexes (NPCs) or as tubule-guided encapsidated particles with the help of movement proteins (MPs). To explore how and why MPs specialize in one mechanism or the other, we tested the exchangeability of MPs encoded by DNA and RNA virus genomes by means of an engineered alfalfa mosaic virus (AMV) system. We show that Caulimoviridae (DNA genome virus) MPs are competent for RNA virus particle transport but are unable to mediate NPC movement, and we discuss this restriction in terms of the evolution of DNA virus MPs as a means of mediating DNA viral genome entry into the RNA-trafficking PD pathway. PMID:20130061

  8. High-Resolution Imaging of Selenium in Kidneys: A Localized Selenium Pool Associated with Glutathione Peroxidase 3

    Science.gov (United States)

    Malinouski, Mikalai; Kehr, Sebastian; Finney, Lydia; Vogt, Stefan; Carlson, Bradley A.; Seravalli, Javier; Jin, Richard; Handy, Diane E.; Park, Thomas J.; Loscalzo, Joseph; Hatfield, Dolph L.

    2012-01-01

    Abstract Aim: Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Results: Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA[Ser]Sec and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. Innovation: We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. Conclusion: XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution. Antioxid. Redox Signal. 16, 185–192. PMID:21854231

  9. Structural and ultrastructural study of the rabbit kidney exposed to carbamate insecticide

    Directory of Open Access Journals (Sweden)

    Viera Almášiová

    2014-01-01

    Full Text Available The aim of the present study was to determine the influence of orally administered insecticide bendiocarb on the structure and ultrastructure of the kidney parenchyma in rabbits. Bendiocarb in the form of capsules (96% Bendiocarb, Bayer, at a dose of 5 mg/kg of body weight was fed daily for 3 days. After sampling, kidney sections of experimental and control animals were evaluated. Under a light and electron microscope the diffuse degenerative changes in kidney cortex and medulla were noted. Light microscopy revealed that the renal corpuscles had normal structure, but other nephron components and the collecting ducts were invariably changed. The epithelial cells inside the proximal and distal tubules and collecting ducts possessed increased quantity of cytoplasmic vacuoles and some tubular sections showed cellular sloughing and necrotization. The cells within the thin limbs of the Henley’s loops had normal histological structure except for sporadic necrotizing cells within some segments. The ultrastructural evaluation showed extensive cytoplasmic vacuolisation and degenerative changes, such as mitochondrial swelling and shortening of basal infoldings within proximal and distal tubules, and microvilli reduction within proximal tubules. Cells of the collecting tubules exhibited a higher number of vacuoles and some cells had apparently reduced organelles. The cells of the thin limbs of the Henle’s loop showed more vacuolised cytoplasm, some tubular sections revealed cellular detachment between the adjacent epithelial cells and rare necrotising epithelial cells were observed. The described findings addressed in the present study indicate an adverse effect of bendiocarb on the kidney parenchyma in rabbits.

  10. Localization of Secondary Metabolites in Marine Invertebrates: Contribution of MALDI MSI for the Study of Saponins in Cuvierian Tubules of H. forskali

    Science.gov (United States)

    Meriaux, Céline; Bonnel, David; Salzet, Michel; Fournier, Isabelle; Wisztorski, Maxence

    2010-01-01

    Background Several species of sea cucumbers of the family Holothuriidae possess a particular mechanical defense system called the Cuvierian tubules (Ct). It is also a chemical defense system as triterpene glycosides (saponins) appear to be particularly concentrated in Ct. In the present study, the precise localization of saponins in the Ct of Holothuria forskali is investigated. Classical histochemical labeling using lectin was firstly performed but did not generate any conclusive results. Thus, MALDI mass spectrometry Imaging (MALDI-MSI) was directly applied and completed by statistical multivariate tests. A comparison between the tubules of relaxed and stressed animals was realized. Results These analyses allowed the detection of three groups of ions, corresponding to the isomeric saponins of the tubules. Saponins detected at m/z 1287 and 1303 were the most abundant and were apparently localized in the connective tissue of the tubules of both relaxed and stressed individuals. Saponins at m/z 1125 and 1141 were detected in lower amount and were present in tissues of relaxed animals. Finally, saponin ions at 1433, 1449, 1463 and 1479 were observed in some Ct of stressed holothuroids in the outer part of the connective tissue. The saponin group m/z 14xx seems therefore to be stress-specific and could originate from modifications of the saponins with m/z of 11xx. Conclusions All the results taken together indicate a complex chemical defense mechanism with, for a single organ, different sets of saponins originating from different cell populations and presenting different responses to stress. The present study also reflects that MALDI-MSI is a valuable tool for chemical ecology studies in which specific chemical signalling molecules like allelochemicals or pheromones have to be tracked. This report represents one of the very first studies using these tools to provide a functional and ecological understanding of the role of natural products from marine invertebrates

  11. Proteomic-based insight into Malpighian tubules of silkworm Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Xiao-wu Zhong

    Full Text Available Malpighian tubules (MTs are highly specific organs of arthropods (Insecta, Myriapoda and Arachnida for excretion and osmoregulation. In order to highlight the important genes and pathways involved in multi-functions of MTs, we performed a systematic proteomic analysis of silkworm MTs in the present work. Totally, 1,367 proteins were identified by one-dimensional gel electrophoresis coupled with liquid chromatography-tandem mass spectrometry, and as well as by Trans Proteomic Pipeline (TPP and Absolute protein expression (APEX analyses. Forty-one proteins were further identified by two-dimensional gel electrophoresis. Some proteins were revealed to be significantly associated with various metabolic processes, organic solute transport, detoxification and innate immunity. Our results might lay a good foundation for future functional studies of MTs in silkworm and other lepidoptera.

  12. A novel member of the trehalose transporter family functions as an H+-dependent trehalose transporter in the reabsorption of trehalose in Malpighian tubules.

    Directory of Open Access Journals (Sweden)

    Shingo eKikuta

    2012-07-01

    Full Text Available In insects, Malpighian tubules are functionally analogous to mammalian kidneys in that they not only are essential to excrete waste molecules into the lumen but also are responsible for the reabsorption of indispensable molecules, such as sugars, from the lumen to the principal cells. Among sugars, the disaccharide trehalose is highly important to insects because it is the main hemolymph sugar to serve as a source of energy and carbon. The trehalose transporter TRET1 participates in the transfer of newly synthesized trehalose from the fat body across the cellular membrane into the hemolymph. Although transport proteins must play a pivotal role in the reabsorption of trehalose in Malpighian tubules, the molecular context underlying this process remains obscure. Previously, we identified a Tret1 homolog (Nlst8 that is expressed principally in the Malpighian tubules of the brown planthopper (BPH. Here, we used the Xenopus oocyte expression system to show that NlST8 exerts trehalose transport activity that is elevated under low pH conditions. These functional assays indicate that Nlst8 encodes a proton-dependent trehalose transporter (H-TRET1. To examine the involvement of Nlst8 in trehalose reabsorption, we analyzed the sugar composition of honeydew by using BPH with RNAi gene silencing. Trehalose was detected in the honeydew as waste excreted from Nlst8-dsRNA-injected BPH under hyperglycemic conditions. However, trehalose was not expelled from GFP-dsRNA-injected BPH even under hyperglycemic conditions. We conclude that NlST8 could participate in trehalose reabsorption driven by a H+ gradient from the lumen to the principal cells of the Malpighian tubules.

  13. Feulgen-DNA response and chromatin condensation in Malpighian tubules of Melipona rufiventris and Melipona quadrifasciata (Hymenoptera, Apoidea).

    Science.gov (United States)

    Mampumbu, André Roberto; Mello, Maria Luiza S

    2008-08-01

    Melipona quadrifasciata and Melipona rufiventris are stingless bee species which present low and high heterochromatin content, respectively, on their mitotic chromosomes as assessed visually after a C-banding assay. However, these species do not show differences in the C-banding responses of their Malpighian tubule interphase nuclei. In the present study, the Feulgen-DNA response, which could inform on differences in DNA depurination due to differences in chromatin condensation, was compared in the cell nuclei of the Malpighian tubules of these species. It was hypothesized that differences in acid hydrolysis kinetics patterns, as assessed by Feulgen reaction and studied microspectrophotometrically, could discriminate M. quadrifasciata and M. rufiventris interphase nuclei not distinguishable with the C-banding method. Feulgen-DNA values corresponding to more than one ploidy class were found in both species; these values at the hydrolysis time corresponding to the maximal DNA depurination for each ploidy degree were higher in M. quadrifasciata, reflecting a higher DNA content in the Malpighian tubule cell nuclei of this species compared to those of M. rufiventris at the same larval instar. The maximal Feulgen-DNA values of M. quadrifasciata after short (50 min) and long (90 min) hydrolysis times were found to be closer to each other, while those of M. rufiventris occurred sharply at the long hydrolysis time, indicating that DNA depurination in M. quadrifasciata occurred faster. This result is probably related to the involvement of differences in chromatin condensation; it agrees with the idea that M. rufiventris contains more heterochromatin than M. quadrifasciata, which is supported by the analysis of results obtained with the image analysis parameter average absorption ratio. The depurination kinetics studied here with the Feulgen reaction were revealed to be more pertinent than the C-banding technique in establishing differences in levels of chromatin condensation

  14. PROXIMITY MANAGEMENT IN CRISIS CONDITIONS

    Directory of Open Access Journals (Sweden)

    Ion Dorin BUMBENECI

    2010-01-01

    Full Text Available The purpose of this study is to evaluate the level of assimilation for the terms "Proximity Management" and "Proximity Manager", both in the specialized literature and in practice. The study has two parts: the theoretical research of the two terms, and an evaluation of the use of Proximity management in 32 companies in Gorj, Romania. The object of the evaluation resides in 27 companies with less than 50 employees and 5 companies with more than 50 employees.

  15. Prenatal diagnosis and molecular cytogenetic characterization of a de novo proximal interstitial deletion of chromosome 4p (4p15.2→p14).

    Science.gov (United States)

    Chen, Chih-Ping; Lee, Meng-Ju; Chern, Schu-Rern; Wu, Peih-Shan; Su, Jun-Wei; Chen, Yu-Ting; Lee, Meng-Shan; Wang, Wayseen

    2013-10-25

    We present prenatal diagnosis of de novo proximal interstitial deletion of chromosome 4p (4p15.2→p14) and molecular cytogenetic characterization of the deletion using uncultured amniocytes. We review the phenotypic abnormalities of previously reported patients with similar proximal interstitial 4p deletions, and we discuss the functions of the genes of RBPJ, CCKAR, STIM2, PCDH7 and ARAP2 that are deleted within this region. © 2013.

  16. Gene Expression of Glucose Transporter 1 (GLUT1), Hexokinase 1 and Hexokinase 2 in Gastroenteropancreatic Neuroendocrine Tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Federspiel, Birgitte Hartnack

    2013-01-01

    -associated genes and to compare this with FDG-PET imaging as well as with the cellular proliferation index in two cancer entities with different malignant potential. Using real-time PCR, gene expression of GLUT1, HK1 and HK2 were studied in 34 neuroendocrine tumors (NETs) in comparison with 14 colorectal...... adenocarcinomas (CRAs). The Ki67 proliferation index and, when available, FDG-PET imaging was compared with gene expression. Overexpression of GLUT1 gene expression was less frequent in NETs (38%) compared to CRAs (86%), P = 0.004. HK1 was overexpressed in 41% and 71% of NETs and CRAs, respectively (P = 0.......111) and HK2 was overexpressed in 50% and 64% of NETs and CRAs, respectively (P = 0.53). There was a significant correlation between the Ki67 proliferation index and GLUT1 gene expression for the NETs (R = 0.34, P = 0.047), but no correlation with the hexokinases. FDG-PET identified foci in significantly...

  17. Residential proximity to major roads and obstetrical complications.

    Science.gov (United States)

    Yorifuji, Takashi; Naruse, Hiroo; Kashima, Saori; Murakoshi, Takeshi; Doi, Hiroyuki

    2015-03-01

    Exposure to air pollution is linked with an increased risk of preterm births. To provide further evidence on this relationship, we evaluated the association between proximity to major roads--as an index for air pollution exposure--and various obstetrical complications. Data were extracted from a database maintained by the perinatal hospital in Shizuoka, Japan. We restricted the analysis to mothers with singleton pregnancies of more than 22 weeks of gestation from 1997 to 2012 (n=19,077). Using the geocoded residential information, each mother was assigned proximity to major roads. We then estimated multivariate adjusted odds ratios and their 95% confidence intervals (CIs) for the effects of proximity to major roads on various obstetrical complications (preeclampsia, gestational diabetes mellitus, placenta abruption, placenta previa, preterm premature rupture of membrane (pPROM), preterm labor, and preterm births). We found positive associations of proximity to major roads with preeclampsia and pPROM. Living within 200 m increased the odds of preeclampsia by 1.3 times (95% CI, 1.0-1.8) and pPROM by 1.6 times (95% CI, 1.1-2.2). Furthermore, living within 200 m increased the odds of preterm births by 1.4 fold (95% CI, 1.2-1.7). Exposure to traffic-related air pollution increased the risk of preeclampsia and pPROM in this study. We propose a mechanism responsible for the association between air pollution and preterm births. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. The Influence of Concentration and Temperature on the Formation of ¿-Oryzanol + ß-Sitosterol Tubules in Edible Oil Organogels

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Venema, P.; Bot, A.; Flöter, E.; Linden, van der E.

    2011-01-01

    The gelation process of mixtures of ¿-oryzanol and sitosterol structurants in sunflower oil was studied using light scattering, rheology, and micro-scanning calorimetry (Micro-DSC). The relation between temperature and the critical aggregation concentration (CAC) of tubule formation of ¿-oryzanol

  19. Review of Proximal Nail Antirotation (PFNA and PFNA-2 – Our Local Experience

    Directory of Open Access Journals (Sweden)

    WL Loo

    2011-07-01

    Full Text Available The proximal femoral nail antirotation (PFNA device was recently introduced as an option for intramedullary management of pertrochanteric hip fractures. We report here local results with this relatively new implant. Sixty-two patients with pertrochanteric or subtrochanteric fractures underwent intramedullary fixation with PFNA devices in our centre during the 14 month period from September 2008 to October 2009. Data for this report were retrieved from clinical case records and operative notes. We recorded the age, gender, length of stay and operative time, preoperative ambulatory status and days required to regain mobility. Fractures were classified using the AO classification (A1, A2 and A3. Complications were also identified.There were 15 male and 47 female patients and the mean age was 74.3 years. The mean surgical duration was 76.1min and the average length of hospitalisation was 14.5 days. Five cases were noted to have femoral shaft fracture and no occurrences of screw cutout. We found that 83.9% of the patients were able to regain preoperative mobility status by 6 months following surgery. We conclude that the PFNA is an effective implant for stabilisation of proximal hip fractures and that the local complication rate is similar to reports from other centres.

  20. Pathology and proposed pathophysiology of diclofenac poisoning in free-living and experimentally exposed oriental white-backed vultures (Gyps bengalensis)

    Science.gov (United States)

    Meteyer, C.U.; Rideout, B.A.; Gilbert, M.; Shivaprasad, H.L.; Oaks, J.L.

    2005-01-01

    Oriental white-backed vultures (Gyps bengalensis; OWBVs) died of renal failure when they ingested diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), in tissues of domestic livestock. Acute necrosis of proximal convoluted tubules in these vultures was severe. Glomeruli, distal convoluted tubules, and collecting tubules were relatively spared in the vultures that had early lesions. In most vultures, however, lesions became extensive with large urate aggregates obscuring renal architecture. Inflammation was minimal. Extensive urate precipitation on the surface and within organ parenchyma (visceral gout) was consistently found in vultures with renal failure. Very little is known about the physiologic effect of NSAIDs in birds. Research in mammals has shown that diclofenac inhibits formation of prostaglandins. We propose that the mechanism by which diclofenac induces renal failure in the OWBV is through the inhibition of the modulating effect of prostaglandin on angiotensin II-mediated adrenergic stimulation. Renal portal valves open in response to adrenergic stimulation, redirecting portal blood to the caudal vena cava and bypassing the kidney. If diclofenac removes a modulating effect of prostaglandins on the renal portal valves, indiscriminant activation of these valves would redirect the primary nutrient blood supply away from the renal cortex. Resulting ischemic necrosis of the cortical proximal convoluted tubules would be consistent with our histologic findings in these OWBVs.