Bmi-1 plays a critical role in the protection from acute tubular necrosis by mobilizing renal stem/progenitor cells.

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Lv, Xianhui; Yu, Zhenzhen; Xie, Chunfeng; Dai, Xiuliang; Li, Qing; Miao, Dengshun; Jin, Jianliang

2017-01-22

The regeneration of injured tubular cell occurs primarily from intrinsic renal stem/progenitor cells (RSCs) labeled with CD24 and CD133 after acute tubular necrosis (ATN). Bmi-1 plays a crucial role in regulating self-renewal, differentiation and aging of multiple adult stem cells and progenitor cells. Bmi-1 was rapidly elevated in the induction of adult kidney regeneration by renal injury. To determine whether Bmi-1 maintained mobilization of RSCs in the protection from ATN, glycerol-rhabdomyolysis-induced ATN were performed in wild type (WT) and Bmi-1-deficient (Bmi-1 -/- ) mice. Their ATN phenotypes were analyzed; CD24 and CD133 double positive (CD24 + CD133 + ) cells were measured; and the levels of serum urea nitrogen (SUN) and serum creatinine (SCr) were detected. We found that CD24 + CD133 + RSCs were mobilized in WT ATN mice with the increased expression of Bmi-1; Bmi-1 deficiency led to increased tubular cast formation and necrosis, elevated levels of SUN and SCr, decreased tubular proliferation, and immobilized ratio of RSCs in ATN. These findings indicated that Bmi-1 played a critical role in the protection from ATN by maintaining mobilization of RSCs and would be a novel therapeutic target for preventing the progression of ATN. Copyright © 2016 Elsevier Inc. All rights reserved.

Hydrogel-embedded endothelial progenitor cells evade LPS and mitigate endotoxemia.

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Ghaly, Tammer; Rabadi, May M; Weber, Mia; Rabadi, Seham M; Bank, Michael; Grom, John M; Fallon, John T; Goligorsky, Michael S; Ratliff, Brian B

2011-10-01

Sepsis and its complications are associated with poor clinical outcomes. The circulatory system is a well-known target of lipopolysaccharide (LPS). Recently, several clinical studies documented mobilization of endothelial progenitor cells (EPCs) during endotoxemia, with the probability of patients' survival correlating with the rise in circulating EPCs. This fact combined with endotoxemia-induced vascular injury led us to hypothesize that the developing functional EPC incompetence could impede vascular repair and that adoptive transfer of EPCs could improve hemodynamics in endotoxemia. We used LPS injection to model endotoxemia. EPCs isolated from endotoxemic mice exhibited impaired clonogenic potential and LPS exerted Toll-like receptor 4-mediated cytotoxic effects toward EPCs, which was mitigated by embedding them in hyaluronic acid (HA) hydrogels. Therefore, intact EPCs were either delivered intravenously or embedded within pronectin-coated HA hydrogels. Adoptive transfer of EPCs in LPS-injected mice improved control of blood pressure and reduced hepatocellular and renal dysfunction. Specifically, EPC treatment was associated with the restoration of renal microcirculation and improved renal function. EPC therapy was most efficient when cells were delivered embedded in HA hydrogel. These findings establish major therapeutic benefits of adoptive transfer of EPCs, especially when embedded in HA hydrogels, in mice with LPS-induced endotoxemia, and they argue that hemodynamic and renal abnormalities of endotoxemia are in significant part due to developing incompetence of endogenous EPCs.

Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion.

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Aleksandra Piwko-Czuchra

Full Text Available BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in their absence, while in vitro data have shown a fundamental role for these adhesion receptors in stem/progenitor cell expansion and differentiation. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate this discrepancy we generated hypomorphic mice expressing reduced beta1 integrin levels on keratinocytes that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis.

Suppression of slow capacitance relaxation phenomenon in Pt/Ba0.3Sr0.7TiO3/Pt thin film ferroelectric structures by annealing in oxygen atmosphere

KAUST Repository

Altynnikov, A. G.

2014-01-27

The impact of oxygen annealing on the switching time of ferroelectric thin film capacitor structures Pt/Ba0.3Sr0.7TiO3/Pt was investigated. The response of their capacitance on pulsed control voltages before and after annealing was experimentally measured. It was demonstrated that the annealing results in suppression of the capacitance slow relaxation processes and increase of the threshold control voltages. These structures can therefore be attractive for fabrication of fast acting microwave devices. © 2014 Author(s).

Insulin-mediated increases in renal plasma flow are impaired in insulin-resistant normal subjects

NARCIS (Netherlands)

ter Maaten, JC; Bakker, SJL; Serne, EH; Moshage, HJ; Gans, ROB

2000-01-01

Background Impaired vasodilatation in skeletal muscle is a possible mechanism linking insulin resistance to blood pressure regulation. Increased renal vascular resistance has been demonstrated in the offspring of essential hypertensives. We assessed whether insulin-mediated renal vasodilatation is

Beta1 integrin-mediated adhesion signalling is essential for epidermal progenitor cell expansion

DEFF Research Database (Denmark)

Piwko-Czuchra, Aleksandra; Koegel, Heidi; Meyer, Hannelore

2009-01-01

BACKGROUND: There is a major discrepancy between the in vitro and in vivo results regarding the role of beta1 integrins in the maintenance of epidermal stem/progenitor cells. Studies of mice with skin-specific ablation of beta1 integrins suggested that epidermis can form and be maintained in thei...... of increased keratinocyte proliferation such as wound healing. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that expression of beta1 integrins is critically important for the expansion of epidermal progenitor cells to maintain epidermal homeostasis....... that developed similar, but less severe defects than mice with beta1-deficient keratinocytes. Surprisingly we found that upon aging these abnormalities attenuated due to a rapid expansion of cells, which escaped or compensated for the down-regulation of beta1 integrin expression. A similar phenomenon...... was observed in aged mice with a complete, skin-specific ablation of the beta1 integrin gene, where cells that escaped Cre-mediated recombination repopulated the mutant skin in a very short time period. The expansion of beta1 integrin expressing keratinocytes was even further accelerated in situations...

Strategies to reverse endothelial progenitor cell dysfunction in diabetes.

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Petrelli, Alessandra; Di Fenza, Raffaele; Carvello, Michele; Gatti, Francesca; Secchi, Antonio; Fiorina, Paolo

2012-01-01

Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

Strategies to Reverse Endothelial Progenitor Cell Dysfunction in Diabetes

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Alessandra Petrelli

2012-01-01

Full Text Available Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial, their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs. Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

H4 histamine receptors mediate cell cycle arrest in growth factor-induced murine and human hematopoietic progenitor cells.

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Anne-France Petit-Bertron

Full Text Available The most recently characterized H4 histamine receptor (H4R is expressed preferentially in the bone marrow, raising the question of its role during hematopoiesis. Here we show that both murine and human progenitor cell populations express this receptor subtype on transcriptional and protein levels and respond to its agonists by reduced growth factor-induced cell cycle progression that leads to decreased myeloid, erythroid and lymphoid colony formation. H4R activation prevents the induction of cell cycle genes through a cAMP/PKA-dependent pathway that is not associated with apoptosis. It is mediated specifically through H4R signaling since gene silencing or treatment with selective antagonists restores normal cell cycle progression. The arrest of growth factor-induced G1/S transition protects murine and human progenitor cells from the toxicity of the cell cycle-dependent anticancer drug Ara-C in vitro and reduces aplasia in a murine model of chemotherapy. This first evidence for functional H4R expression in hematopoietic progenitors opens new therapeutic perspectives for alleviating hematotoxic side effects of antineoplastic drugs.

MT1-MMP-mediated basement membrane remodeling modulates renal development

International Nuclear Information System (INIS)

Riggins, Karen S.; Mernaugh, Glenda; Su, Yan; Quaranta, Vito; Koshikawa, Naohiko; Seiki, Motoharu; Pozzi, Ambra; Zent, Roy

2010-01-01

Extracellular matrix (ECM) remodeling regulates multiple cellular functions required for normal development and tissue repair. Matrix metalloproteinases (MMPs) are key mediators of this process and membrane targeted MMPs (MT-MMPs) in particular have been shown to be important in normal development of specific organs. In this study we investigated the role of MT1-MMP in kidney development. We demonstrate that loss of MT1-MMP leads to a renal phenotype characterized by a moderate decrease in ureteric bud branching morphogenesis and a severe proliferation defect. The kidneys of MT1-MMP-null mice have increased deposition of collagen IV, laminins, perlecan, and nidogen and the phenotype is independent of the MT-1MMP target, MMP-2. Utilizing in vitro systems we demonstrated that MTI-MMP proteolytic activity is required for renal tubule cells to proliferate in three dimensional matrices and to migrate on collagen IV and laminins. Together these data suggest an important role for MT1-MMP in kidney development, which is mediated by its ability to regulate cell proliferation and migration by proteolytically cleaving kidney basement membrane components.

Proliferative capacity of stem/progenitor-like cells in the kidney may associate with the outcome of patients with acute tubular necrosis.

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Ye, Youxin; Wang, Bingyin; Jiang, Xinxin; Hu, Weiming; Feng, Jian; Li, Hua; Jin, Mei; Ying, Yingjuan; Wang, Wenjuan; Mao, Xiaoou; Jin, Kunlin

2011-08-01

Animal studies indicate that adult renal stem/progenitor cells can undergo rapid proliferation in response to renal injury, but whether the same is true in humans is largely unknown. To examine the profile of renal stem/progenitor cells responsible for acute tubular necrosis in human kidney, double and triple immunostaining was performed using proliferative marker and stem/progenitor protein markers on sections from 10 kidneys with acute tubular necrosis and 4 normal adult kidneys. The immunopositive cells were recorded using 2-photon confocal laser scanning microscopy. We found that dividing cells were present in the tubules of the cortex and medulla, as well as the glomerulus in normal human kidney. Proliferative cells in the parietal layer of Bowman capsule expressed CD133, and dividing cells in the tubules expressed immature cell protein markers paired box gene 2, vimentin, and nestin. After acute tubular necrosis, Ki67-positive cells in the cortex tubules significantly increased compared with normal adult kidney. These Ki67-positive cells expressed CD133 and paired box gene 2, but not the cell death marker, activated caspase-3. In addition, the number of dividing cells increased significantly in patients with acute tubular necrosis who subsequently recovered, compared with patients with acute tubular necrosis who consequently developed protracted acute tubular necrosis or died. Our data suggest that renal stem/progenitor cells may reside not only in the parietal layer of Bowman capsule but also in the cortex and medulla in normal human kidney, and the proliferative capacity of renal stem/progenitor cells after acute tubular necrosis may be an important determinant of a patient's outcome. Copyright © 2011 Elsevier Inc. All rights reserved.

Selective In Vitro Propagation of Nephron Progenitors Derived from Embryos and Pluripotent Stem Cells

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Shunsuke Tanigawa

2016-04-01

Full Text Available Nephron progenitors in the embryonic kidney propagate while generating differentiated nephrons. However, in mice, the progenitors terminally differentiate shortly after birth. Here, we report a method for selectively expanding nephron progenitors in vitro in an undifferentiated state. Combinatorial and concentration-dependent stimulation with LIF, FGF2/9, BMP7, and a WNT agonist is critical for expansion. The purified progenitors proliferated beyond the physiological limits observed in vivo, both for cell numbers and lifespan. Neonatal progenitors were maintained for a week, while progenitors from embryonic day 11.5 expanded 1,800-fold for nearly 20 days and still reconstituted 3D nephrons containing glomeruli and renal tubules. Furthermore, progenitors generated from mouse embryonic stem cells and human induced pluripotent cells could be expanded with retained nephron-forming potential. Thus, we have established in vitro conditions for promoting the propagation of nephron progenitors, which will be essential for dissecting the mechanisms of kidney organogenesis and for regenerative medicine.

X Inactivation and Progenitor Cancer Cells

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Ruben Agrelo

2011-04-01

Full Text Available In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

Endothelial progenitor cell dysfunction in patients with progressive chronic kidney disease

NARCIS (Netherlands)

Krenning, Guido; Dankers, Patricia Y. W.; Drouven, Johannes W.; Waanders, Femke; Franssen, Casper F. M.; van Luyn, Marja J. A.; Harmsen, Martin C.; Popa, Eliane R.

Krenning G, Dankers PY, Drouven JW, Waanders F, Franssen CF, van Luyn MJ, Harmsen MC, Popa ER. Endothelial progenitor cell dysfunction in patients with progressive chronic kidney disease. Am J Physiol Renal Physiol 296: F1314-F1322, 2009. First published April 1, 2009; doi:

Exercise training attenuates chemoreflex-mediated reductions of renal blood flow in heart failure.

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Marcus, Noah J; Pügge, Carolin; Mediratta, Jai; Schiller, Alicia M; Del Rio, Rodrigo; Zucker, Irving H; Schultz, Harold D

2015-07-15

In chronic heart failure (CHF), carotid body chemoreceptor (CBC) activity is increased and contributes to increased tonic and hypoxia-evoked elevation in renal sympathetic nerve activity (RSNA). Elevated RSNA and reduced renal perfusion may contribute to development of the cardio-renal syndrome in CHF. Exercise training (EXT) has been shown to abrogate CBC-mediated increases in RSNA in experimental heart failure; however, the effect of EXT on CBC control of renal blood flow (RBF) is undetermined. We hypothesized that CBCs contribute to tonic reductions in RBF in CHF, that stimulation of the CBC with hypoxia would result in exaggerated reductions in RBF, and that these responses would be attenuated with EXT. RBF was measured in CHF-sedentary (SED), CHF-EXT, CHF-carotid body denervation (CBD), and CHF-renal denervation (RDNX) groups. We measured RBF at rest and in response to hypoxia (FiO2 10%). All animals exhibited similar reductions in ejection fraction and fractional shortening as well as increases in ventricular systolic and diastolic volumes. Resting RBF was lower in CHF-SED (29 ± 2 ml/min) than in CHF-EXT animals (46 ± 2 ml/min, P < 0.05) or in CHF-CBD animals (42 ± 6 ml/min, P < 0.05). In CHF-SED, RBF decreased during hypoxia, and this was prevented in CHF-EXT animals. Both CBD and RDNX abolished the RBF response to hypoxia in CHF. Mean arterial pressure increased in response to hypoxia in CHF-SED, but was prevented by EXT, CBD, and RDNX. EXT is effective in attenuating chemoreflex-mediated tonic and hypoxia-evoked reductions in RBF in CHF. Copyright © 2015 the American Physiological Society.

Purinergic Signalling in Inflammatory Renal Disease

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Nishkantha eArulkumaran

2013-07-01

Full Text Available Extracellular purines have a role in renal physiology and adaption to inflammation. However, inflammatory renal disease may be mediated by extracellular purines, resulting in renal injury. The role of purinergic signalling is dependent on the concentrations of extracellular purines. Low basal levels of purines are important in normal homeostasis and growth. Concentrations of extracellular purines are significantly elevated during inflammation and mediate either an adaptive role or propagate local inflammation. Adenosine signalling mediates alterations in regional renal blood flow by regulation of the renal microcirculation, tubulo-glomerular feedback, and tubular transport of sodium and water. Increased extracellular ATP and renal P2 receptor-mediated inflammation are associated with various renal diseases, including hypertension, diabetic nephropathy, and glomerulonephritis. Experimental data suggests P2 receptor deficiency or receptor antagonism is associated with amelioration of antibody-mediated nephritis, suggesting a pathogenic (rather than adaptive role of purinergic signalling. We discuss the role of extracellular nucleotides in adaptation to ischaemic renal injury and in the pathogenesis of inflammatory renal disease.

Selective In Vitro Propagation of Nephron Progenitors Derived from Embryos and Pluripotent Stem Cells.

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Tanigawa, Shunsuke; Taguchi, Atsuhiro; Sharma, Nirmala; Perantoni, Alan O; Nishinakamura, Ryuichi

2016-04-26

Nephron progenitors in the embryonic kidney propagate while generating differentiated nephrons. However, in mice, the progenitors terminally differentiate shortly after birth. Here, we report a method for selectively expanding nephron progenitors in vitro in an undifferentiated state. Combinatorial and concentration-dependent stimulation with LIF, FGF2/9, BMP7, and a WNT agonist is critical for expansion. The purified progenitors proliferated beyond the physiological limits observed in vivo, both for cell numbers and lifespan. Neonatal progenitors were maintained for a week, while progenitors from embryonic day 11.5 expanded 1,800-fold for nearly 20 days and still reconstituted 3D nephrons containing glomeruli and renal tubules. Furthermore, progenitors generated from mouse embryonic stem cells and human induced pluripotent cells could be expanded with retained nephron-forming potential. Thus, we have established in vitro conditions for promoting the propagation of nephron progenitors, which will be essential for dissecting the mechanisms of kidney organogenesis and for regenerative medicine. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Levels of circulating CD45dimCD34+VEGFR2+ progenitor cells correlate with outcome in metastatic renal cell carcinoma patients treated with tyrosine kinase inhibitors

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Farace, F; Gross-Goupil, M; Tournay, E; Taylor, M; Vimond, N; Jacques, N; Billiot, F; Mauguen, A; Hill, C; Escudier, B

2011-01-01

Background: Predicting the efficacy of antiangiogenic therapy would be of clinical value in patients (pts) with metastatic renal cell carcinoma (mRCC). We tested the hypothesis that circulating endothelial cell (CEC), bone marrow-derived CD45dimCD34+VEGFR2+ progenitor cell or plasma angiogenic factor levels are associated with clinical outcome in mRCC pts undergoing treatment with tyrosine kinase inhibitors (TKI). Methods: Fifty-five mRCC pts were prospectively monitored at baseline (day 1) and day 14 during treatment (46 pts received sunitinib and 9 pts received sorafenib). Circulating endothelial cells (CD45−CD31+CD146+7-amino-actinomycin (7AAD)− cells) were measured in 1 ml whole blood using four-color flow cytometry (FCM). Circulating CD45dimCD34+VEGFR2+7AAD− progenitor cells were measured in progenitor-enriched fractions by four-color FCM. Plasma VEGF, sVEGFR2, SDF-1α and sVCAM-1 levels were determined by ELISA. Correlations between baseline CEC, CD45dimCD34+VEGFR2+7AAD− progenitor cells, plasma factors, as well as day 1–day 14 changes in CEC, CD45dimCD34+VEGFR2+7AAD− progenitor, plasma factor levels, and response to TKI, progression-free survival (PFS) and overall survival (OS) were examined. Results: No significant correlation between markers and response to TKI was observed. No association between baseline CEC, plasma VEGF, sVEGFR-2, SDF-1α, sVCAM-1 levels with PFS and OS was observed. However, baseline CD45dimCD34+VEGFR2+7AAD− progenitor cell levels were associated with PFS (P=0.01) and OS (P=0.006). Changes in this population and in SDF-1α levels between day 1 and day 14 were associated with PFS (P=0.03, P=0.002). Changes in VEGF and SDF-1α levels were associated with OS (P=0.02, P=0.007). Conclusion: Monitoring CD45dimCD34+VEGFR2+ progenitor cells, plasma VEGF and SDF-1α levels could be of clinical interest in TKI-treated mRCC pts to predict outcome. PMID:21386843

Pretreatment of Sialic Acid Efficiently Prevents Lipopolysaccharide-Induced Acute Renal Failure and Suppresses TLR4/gp91-Mediated Apoptotic Signaling

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Shih-Ping Hsu

2016-05-01

Full Text Available Background/Aims: Lipopolysaccharides (LPS binding to Toll-like receptor 4 (TLR4 activate NADPH oxidase gp91 subunit-mediated inflammation and oxidative damage. Recognizing the high binding affinity of sialic acid (SA with LPS, we further explored the preventive potential of SA pretreatment on LPS-evoked acute renal failure (ARF. Methods: We determined the effect of intravenous SA 30 min before LPS-induced injury in urethane-anesthetized female Wistar rats by evaluating kidney reactive oxygen species (ROS responses, renal and systemic hemodynamics, renal function, histopathology, and molecular mechanisms. Results: LPS time-dependently reduced arterial blood pressure, renal microcirculation, and increased blood urea nitrogen and creatinine in the rats. LPS enhanced monocyte/macrophage infiltration and ROS production, and subsequently impaired kidneys with the enhancement of TLR4/NADPH oxidase gp91/Caspase 3/poly-(ADP-ribose-polymerase (PARP-mediated apoptosis in the kidneys. SA pretreatment effectively alleviated LPS-induced ARF. The levels of LPS-increased ED-1 infiltration and ROS production in the kidney were significantly depressed by SA pretreatment. Furthermore, SA pretreatment significantly depressed TLR4 activation, gp91 expression, and Caspase 3/PARP induced apoptosis in the kidneys. Conclusion: We suggest that pretreatment of SA significantly and preventively attenuated LPS-induced detrimental effects on systemic and renal hemodynamics, renal ROS production and renal function, as well as, LPS-activated TLR4/gp91/Caspase3 mediated apoptosis signaling.

Engineering kidney cells: reprogramming and directed differentiation to renal tissues.

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Kaminski, Michael M; Tosic, Jelena; Pichler, Roman; Arnold, Sebastian J; Lienkamp, Soeren S

2017-07-01

Growing knowledge of how cell identity is determined at the molecular level has enabled the generation of diverse tissue types, including renal cells from pluripotent or somatic cells. Recently, several in vitro protocols involving either directed differentiation or transcription-factor-based reprogramming to kidney cells have been established. Embryonic stem cells or induced pluripotent stem cells can be guided towards a kidney fate by exposing them to combinations of growth factors or small molecules. Here, renal development is recapitulated in vitro resulting in kidney cells or organoids that show striking similarities to mammalian embryonic nephrons. In addition, culture conditions are also defined that allow the expansion of renal progenitor cells in vitro. Another route towards the generation of kidney cells is direct reprogramming. Key transcription factors are used to directly impose renal cell identity on somatic cells, thus circumventing the pluripotent stage. This complementary approach to stem-cell-based differentiation has been demonstrated to generate renal tubule cells and nephron progenitors. In-vitro-generated renal cells offer new opportunities for modelling inherited and acquired renal diseases on a patient-specific genetic background. These cells represent a potential source for developing novel models for kidney diseases, drug screening and nephrotoxicity testing and might represent the first steps towards kidney cell replacement therapies. In this review, we summarize current approaches for the generation of renal cells in vitro and discuss the advantages of each approach and their potential applications.

Icariin protects rats against 5/6 nephrectomy-induced chronic kidney failure by increasing the number of renal stem cells.

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Huang, Zhongdi; He, Liqun; Huang, Di; Lei, Shi; Gao, Jiandong

2015-10-21

Chronic kidney disease poses a serious health problem worldwide with increasing prevalence and lack of effective treatment. This study aimed to investigate the mechanism of icariin in alleviating chronic renal failure induced by 5/6 nephrectomy in rats. The chronic renal failure model was established by a two-phased 5/6 nephrectomy procedure. The model rats were given daily doses of water or icariin for 8 weeks. The kidney morphology was checked by HE staining. The levels of blood urea nitrogen, serum creatinine, and serum uric acid were measured by colometric methods. The expression of specified genes was analyzed by quantitative real-time PCR and immunohistochemical staining. The number of renal stem/progenitor cells was analyzed by CD133 and CD24 immunohistochemical staining. Icariin protected against CDK-caused damages to kidney histology and improved renal function, significantly reduced levels of BUN, creatinine, and uric acid. Icariin inhibited the expression level of TGF-β1 whereas upregulated HGF, BMP-7, WT-1, and Pax2 expression. Moreover, ccariin significantly increased the expression of CD24, CD133, Osr1, and Nanog in remnant kidney and the numbers of CD133(+)/CD24(+) renal stem/progenitor cells. These data demonstrated that icariin effectively alleviated 5/6 nephrectomy induced chronic renal failure through increasing renal stem/progenitor cells.

Reduced kidney lipoprotein lipase and renal tubule triglyceride accumulation in cisplatin-mediated acute kidney injury

NARCIS (Netherlands)

Li, Shenyang; Nagothu, K.; Ranganathan, G.; Ali, S.M.; Shank, B.; Gokden, N.; Ayyadevara, S.; Megysi, J.; Olivecrona, G.; Chugh, S.S.; Kersten, A.H.; Portilla, D.

2012-01-01

Peroxisome proliferator-activated receptor-a (PPARa) activation attenuates cisplatin (CP)-mediated acute kidney injury by increasing fatty acid oxidation, but mechanisms leading to reduced renal triglyceride (TG) accumulation could also contribute. Here, we investigated the effects of PPARa and CP

Fructokinase activity mediates dehydration-induced renal injury.

Science.gov (United States)

Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

2014-08-01

The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

Isolation and characterization of multipotent progenitor cells from the Bowman's capsule of adult human kidneys.

Science.gov (United States)

Sagrinati, Costanza; Netti, Giuseppe Stefano; Mazzinghi, Benedetta; Lazzeri, Elena; Liotta, Francesco; Frosali, Francesca; Ronconi, Elisa; Meini, Claudia; Gacci, Mauro; Squecco, Roberta; Carini, Marco; Gesualdo, Loreto; Francini, Fabio; Maggi, Enrico; Annunziato, Francesco; Lasagni, Laura; Serio, Mario; Romagnani, Sergio; Romagnani, Paola

2006-09-01

Regenerative medicine represents a critical clinical goal for patients with ESRD, but the identification of renal adult multipotent progenitor cells has remained elusive. It is demonstrated that in human adult kidneys, a subset of parietal epithelial cells (PEC) in the Bowman's capsule exhibit coexpression of the stem cell markers CD24 and CD133 and of the stem cell-specific transcription factors Oct-4 and BmI-1, in the absence of lineage-specific markers. This CD24+CD133+ PEC population, which could be purified from cultured capsulated glomeruli, revealed self-renewal potential and a high cloning efficiency. Under appropriate culture conditions, individual clones of CD24+CD133+ PEC could be induced to generate mature, functional, tubular cells with phenotypic features of proximal and/or distal tubules, osteogenic cells, adipocytes, and cells that exhibited phenotypic and functional features of neuronal cells. The injection of CD24+CD133+ PEC but not of CD24-CD133- renal cells into SCID mice that had acute renal failure resulted in the regeneration of tubular structures of different portions of the nephron. More important, treatment of acute renal failure with CD24+CD133+ PEC significantly ameliorated the morphologic and functional kidney damage. This study demonstrates the existence and provides the characterization of a population of resident multipotent progenitor cells in adult human glomeruli, potentially opening new avenues for the development of regenerative medicine in patients who have renal diseases.

Matrix metalloproteinase-14 mediates formation of bile ducts and hepatic maturation of fetal hepatic progenitor cells

Energy Technology Data Exchange (ETDEWEB)

Otani, Satoshi [Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo (Japan); Kakinuma, Sei, E-mail: skakinuma.gast@tmd.ac.jp [Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo (Japan); Department for Liver Disease Control, Tokyo Medical and Dental University, Tokyo (Japan); Kamiya, Akihide [Institute of Innovative Science and Technology, Tokai University, Isehara (Japan); Goto, Fumio; Kaneko, Shun; Miyoshi, Masato; Tsunoda, Tomoyuki; Asano, Yu; Kawai-Kitahata, Fukiko; Nitta, Sayuri; Nakata, Toru; Okamoto, Ryuichi; Itsui, Yasuhiro; Nakagawa, Mina; Azuma, Seishin [Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo (Japan); Asahina, Yasuhiro [Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo (Japan); Department for Liver Disease Control, Tokyo Medical and Dental University, Tokyo (Japan); Yamaguchi, Tomoyuki [Division of Stem Cell Therapy, Institute of Medical Science, The University of Tokyo, Tokyo (Japan); Koshikawa, Naohiko [Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Tokyo (Japan); Seiki, Motoharu [Medical School, Kanazawa University, Kanazawa (Japan); Nakauchi, Hiromitsu [Division of Stem Cell Therapy, Institute of Medical Science, The University of Tokyo, Tokyo (Japan); and others

2016-01-22

Fetal hepatic stem/progenitor cells, called hepatoblasts, play central roles in liver development; however, the molecular mechanisms regulating the phenotype of these cells have not been completely elucidated. Matrix metalloproteinase (MMP)-14 is a type I transmembrane proteinase regulating pericellular proteolysis of the extracellular matrix and is essential for the activation of several MMPs and cytokines. However, the physiological functions of MMP-14 in liver development are unknown. Here we describe a functional role for MMP-14 in hepatic and biliary differentiation of mouse hepatoblasts. MMP-14 was upregulated in cells around the portal vein in perinatal stage liver. Formation of bile duct-like structures in MMP-14–deficient livers was significantly delayed compared with wild-type livers in vivo. In vitro biliary differentiation assays showed that formation of cholangiocytic cysts derived from MMP-14–deficient hepatoblasts was completely impaired, and that overexpression of MMP-14 in hepatoblasts promoted the formation of bile duct-like cysts. In contrast, the expression of molecules associated with metabolic functions in hepatocytes, including hepatic nuclear factor 4α and tryptophan 2,3-dioxygenase, were significantly increased in MMP-14–deficient livers. Expression of the epidermal growth factor receptor and phosphorylation of mitogen-activated protein kinases were significantly upregulated in MMP-14–deficient livers. We demonstrate that MMP-14–mediated signaling in fetal hepatic progenitor cells promotes biliary luminal formation around the portal vein and negatively controls the maturation of hepatocytes. - Highlights: • Loss of MMP-14 delayed formation of bile duct-like structures in perinatal liver. • Overexpression of MMP-14 in hepatobalsts promoted the biliary formation in vitro. • Loss of MMP-14 promoted hepatocyte maturation of hepatoblasts in vivo. • MMP-14–mediated signaling regulates terminal differentiation of

Salubrious effect of C-phycocyanin against oxalate-mediated renal cell injury.

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Farooq, Shukkur Muhammed; Asokan, Devarajan; Sakthivel, Ramasamy; Kalaiselvi, Periandavan; Varalakshmi, Palaninathan

2004-10-01

C-phycocyanin, a biliprotein pigment found in some blue green algae (Spirulina platensis) with nutritional and medicinal properties, was investigated for its efficacy on sodium oxalate-induced nephrotoxicity in experimentally induced urolithic rats. Male Wistar rats were divided into four groups. Hyperoxaluria was induced in two of these groups by intraperitoneal infusion of sodium oxalate (70 mg/kg), and a pretreatment of phycocyanin (100 mg/kg) as a single oral dosage was given to one of these groups by 1 h prior to sodium oxalate infusion challenges. The study also encompasses an untreated control group and a phycocyanin-alone treated drug control group. The extent of lipid peroxidation (LPO) was evaluated in terms of renal concentrations of MDA, conjugated diene and hydroperoxides. The following assay was performed in the renal tissue (a) antioxidant enzymes such as superoxide dismutase (SOD) and catalase, (b) glutathione metabolizing enzymes such as glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and glucose 6-phosphate dehydrogenase (G6PD), (c) the low molecular weight antioxidants (GSH, vitamins E and C) and protein carbonyl content. The increased concentrations of MDA, conjugated diene and hydroperoxide (index of the lipid peroxidation) were controlled (P antioxidants were appreciably increased (P antioxidants. It was noticed that the activities of antioxidant enzymes and glutathione metabolizing enzymes were considerably stabilized in rats pretreated with phycocyanin. We suggest that phycocyanin protects the integrity of the renal cell by stabilizing the free radical mediated LPO and protein carbonyl, as well as low molecular weight antioxidants and antioxidant enzymes in renal cells. Thus, the present analysis reveals that the antioxidant nature of C-phycocyanin protects the renal cell against oxalate-induced injury and may be a nephroprotective agent.

What is the functional background of filigree extracellular matrix and cell-cell connections at the interface of the renal stem/progenitor cell niche?

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Will W. Minuth

2015-12-01

Full Text Available Development of a nephron is induced by a reciprocal exchange of morphogenetic proteins between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. For sustaining concentration of diffusing proteins high, it is believed that an intimate contact exists between involved cells. However, actual morphological data show that both types of stem/progenitor cell bodies are separated by an interface. To analyze details of this arrangement, neonatal rabbit kidneys were fixed in traditional glutaraldehyde (GA solution for transmission electron microscopy. For an enhanced contrast fixation of samples was performed in GA solution including either cupromeronic blue, ruthenium red or tannic acid. To record always the same perspective, embedded blocks of parenchyma were cut in orientated vertical and transverse planes to the lumen of lining collecting duct tubules. Screening of samples fixed by GA solution demonstrates a constant separation of stem/progenitor cell bodies by an unobstrusively looking interface. In contrast, improved fixation of specimens in GA solution including cupromeronic blue, ruthenium red or tannic acid unveils between them earlier not visible filigree extracellular matrix. Further projections of mesenchymal cells covered by this matrix cross the interface to contact epithelial cells. The end of a projection does not dangle but is mounted by a special plug connection. At this site the plasma membranes of mesenchymal and epithelial cells are connected via tunneling nanotubes. Regarding this unique arrangement the principal question is to what extent illustrated extracellular matrix and cell-cell connections are involved in the exchange of morphogenetic proteins during induction of a nephron. Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future

Long-term experience of plasmapheresis in antibody-mediated rejection in renal transplantation.

LENUS (Irish Health Repository)

Brown, C M

2009-11-01

Antibody-mediated rejection (AMR) continues to pose a serious challenge in renal transplantation with potentially devastating consequences. Treatment options for this condition include plasmapheresis, high-dose intravenous immunoglobulin (IVIG), plasmapheresis with low-dose IVIG, and the use of rituximab (anti-CD20 chimeric antibody). We previously reported on the short-term outcome of plasmapheresis as a rescue therapy for AMR in our centre. We now report on the long-term follow up.

Protocatechuic aldehyde attenuates cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation

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Li Gao

2016-12-01

Full Text Available Cisplatin is a classic chemotherapeutic agent widely used to treat different types of cancers including ovarian, head and neck, testicular and uterine cervical carcinomas. However, cisplatin induces acute kidney injury by directly triggering an excessive inflammatory response, oxidative stress and programmed cell death of renal tubular epithelial cells. All of which lead to higher mortality rates in patients. In this study we examined the protective effect of protocatechuic aldehyde (PA in vitro in cisplatin-treated tubular epithelial cells and in vivo in cisplatin nephropathy. PA is a monomer of Traditional Chinese Medicine isolated from the root of S. miltiorrhiza. Results show that PA prevented cisplatin-induced decline of renal function and histological damage, which was confirmed by attenuation of KIM1 in both mRNA and protein levels. Moreover, PA reduced renal inflammation by suppressing oxidative stress and programmed cell death in response to cisplatin, which was further evidenced by in vitro data. Of note, PA suppressed NAPDH oxidases, including Nox2 and Nox4, in a dosage-dependent manner. Moreover, silencing Nox4, but not Nox2, removed the inhibitory effect of PA on cisplatin-induced renal injury, indicating that Nox4 may play a pivotal role in mediating the protective effect of PA in cisplatin-induced acute kidney injury. Collectively, our data indicate that PA largely blocked cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation without compromising anti-tumor activity of cisplatin. These findings suggest that PA and its derivatives may serve as potential protective agents for cancer patients with cisplatin treatment.

A novel chalcone derivative attenuates the diabetes-induced renal injury via inhibition of high glucose-mediated inflammatory response and macrophage infiltration

International Nuclear Information System (INIS)

Fang, Qilu; Zhao, Leping; Wang, Yi; Zhang, Yali; Li, Zhaoyu; Pan, Yong; Kanchana, Karvannan; Wang, Jingying; Tong, Chao; Li, Dan; Liang, Guang

2015-01-01

Inflammation plays a central role in the development and progression of diabetic nephropathy (DN). Researches on novel anti-inflammatory agents may offer new opportunities for the treatment of DN. We previously found a chalcone derivative L6H21 could inhibit LPS-induced cytokine release from macrophages. The aim of this study was to investigate whether L6H21 could ameliorate the high glucose-mediated inflammation in NRK-52E cells and attenuate the inflammation-mediated renal injury. According to the results, L6H21 showed a great inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines, and macrophage adhesion via down-regulation of NF-κB/MAPKs activity in high glucose-stimulated renal NRK-52E cells. Further, in vivo oral administration with L6H21 at a dosage of 20 mg/kg/2 days showed a decreased expression of pro-inflammatory cytokines, cell adhesion molecules, which subsequently contributed to the inhibition on renal macrophage infiltration, the reduction of serum creatinine and BUN levels, and the improvement on the fibrosis and pathological changes in the renal tissues of diabetic mice. These findings provided that chalcone derived L6H21 may be a promising anti-inflammatory agent and have the potential in the therapy of diabetic nephropathy, and importantly, MAPK/NF-κB signaling system may be a novel therapeutic target for human DN in the future. - Highlights: • Inflammation plays a central role in the development of diabetic nephropathy. • Compound L6H21 reduced the high glucose-mediated inflammation in NRK-52E cells. • Compound L6H21 attenuated the inflammation-mediated renal injury. • L6H21 exhibited anti-inflammatory effects via inactivation of NF-κB/MAPKs. • MAPKs/NF-κB may be a novel therapeutic target in diabetic nephropathy treatment

A novel chalcone derivative attenuates the diabetes-induced renal injury via inhibition of high glucose-mediated inflammatory response and macrophage infiltration

Energy Technology Data Exchange (ETDEWEB)

Fang, Qilu [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Zhao, Leping [Department of Pharmacy, the Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wang, Yi; Zhang, Yali [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Li, Zhaoyu [Department of International High School, Shanghai Jiaotong University Nanyang Affiliated (Kunshan) School, Minhang District, Shanghai (China); Pan, Yong; Kanchana, Karvannan; Wang, Jingying; Tong, Chao [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Li, Dan, E-mail: yqyyld@163.com [Department of Nephrology, the Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang (China); Liang, Guang, E-mail: wzmcliangguang@163.com [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China)

2015-01-15

Inflammation plays a central role in the development and progression of diabetic nephropathy (DN). Researches on novel anti-inflammatory agents may offer new opportunities for the treatment of DN. We previously found a chalcone derivative L6H21 could inhibit LPS-induced cytokine release from macrophages. The aim of this study was to investigate whether L6H21 could ameliorate the high glucose-mediated inflammation in NRK-52E cells and attenuate the inflammation-mediated renal injury. According to the results, L6H21 showed a great inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines, and macrophage adhesion via down-regulation of NF-κB/MAPKs activity in high glucose-stimulated renal NRK-52E cells. Further, in vivo oral administration with L6H21 at a dosage of 20 mg/kg/2 days showed a decreased expression of pro-inflammatory cytokines, cell adhesion molecules, which subsequently contributed to the inhibition on renal macrophage infiltration, the reduction of serum creatinine and BUN levels, and the improvement on the fibrosis and pathological changes in the renal tissues of diabetic mice. These findings provided that chalcone derived L6H21 may be a promising anti-inflammatory agent and have the potential in the therapy of diabetic nephropathy, and importantly, MAPK/NF-κB signaling system may be a novel therapeutic target for human DN in the future. - Highlights: • Inflammation plays a central role in the development of diabetic nephropathy. • Compound L6H21 reduced the high glucose-mediated inflammation in NRK-52E cells. • Compound L6H21 attenuated the inflammation-mediated renal injury. • L6H21 exhibited anti-inflammatory effects via inactivation of NF-κB/MAPKs. • MAPKs/NF-κB may be a novel therapeutic target in diabetic nephropathy treatment.

Postnatal epithelium and mesenchyme stem/progenitor cells in bioengineered amelogenesis and dentinogenesis.

Science.gov (United States)

Jiang, Nan; Zhou, Jian; Chen, Mo; Schiff, Michael D; Lee, Chang H; Kong, Kimi; Embree, Mildred C; Zhou, Yanheng; Mao, Jeremy J

2014-02-01

Rodent incisors provide a classic model for studying epithelial-mesenchymal interactions in development. However, postnatal stem/progenitor cells in rodent incisors have not been exploited for tooth regeneration. Here, we characterized postnatal rat incisor epithelium and mesenchyme stem/progenitor cells and found that they formed enamel- and dentin-like tissues in vivo. Epithelium and mesenchyme cells were harvested separately from the apical region of postnatal 4-5 day rat incisors. Epithelial and mesenchymal phenotypes were confirmed by immunocytochemistry, CFU assay and/or multi-lineage differentiation. CK14+, Sox2+ and Lgr5+ epithelium stem cells from the cervical loop enhanced amelogenin and ameloblastin expression upon BMP4 or FGF3 stimulation, signifying their differentiation towards ameloblast-like cells, whereas mesenchyme stem/progenitor cells upon BMP4, BMP7 and Wnt3a treatment robustly expressed Dspp, a hallmark of odontoblastic differentiation. We then control-released microencapsulated BMP4, BMP7 and Wnt3a in transplants of epithelium and mesenchyme stem/progenitor cells in the renal capsule of athymic mice in vivo. Enamel and dentin-like tissues were generated in two integrated layers with specific expression of amelogenin and ameloblastin in the newly formed, de novo enamel-like tissue, and DSP in dentin-like tissue. These findings suggest that postnatal epithelium and mesenchyme stem/progenitor cells can be primed towards bioengineered tooth regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sinomenine attenuates renal fibrosis through Nrf2-mediated inhibition of oxidative stress and TGFβ signaling

Energy Technology Data Exchange (ETDEWEB)

Qin, Tian [School of Life Science & Technology, China Pharmaceutical University, Nanjing 210009 (China); Yin, Shasha; Yang, Jun; Zhang, Qin; Liu, Yangyang [Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing 210093 (China); Huang, Fengjie, E-mail: hfj@cpu.edu.cn [School of Life Science & Technology, China Pharmaceutical University, Nanjing 210009 (China); Cao, Wangsen, E-mail: wangsencao@nju.edu.cn [Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing 210093 (China)

2016-08-01

Renal fibrosis is the common feature of chronic kidney disease and mainly mediated by TGFβ-associated pro-fibrogenic signaling, which causes excessive extracellular matrix accumulation and successive loss of kidney functions. Sinomenine (SIN), an alkaloid derived from medicinal herb extensively used in treatment of rheumatoid arthritis and various inflammatory disorders, displays renal protective properties in experimental animals; however its pharmacological potency against renal fibrosis is not explored. In this study we report that SIN possesses strong anti-renal fibrosis functions in kidney cell and in mouse fibrotic kidney. SIN beneficially modulated the pro-fibrogenic protein expression in TGFβ-treated kidney cells and attenuated the renal fibrotic pathogenesis incurred by unilateral ureteral obstruction (UUO), which correlated with its activation of Nrf2 signaling - the key defender against oxidative stress with anti-fibrotic potentials. Further investigation on its regulation of Nrf2 downstream events revealed that SIN significantly balanced oxidative stress via improving the expression and activity of anti-oxidant and detoxifying enzymes, and interrupted the pro-fibrogenic signaling of TGFβ/Smad and Wnt/β-catenin. Even more impressively SIN achieved its anti-fibrotic activities in an Nrf2-dependent manner, suggesting that SIN regulation of Nrf2-associated anti-fibrotic activities constitutes a critical component of SIN's renoprotective functions. Collectively our studies have demonstrated a novel anti-fibrotic property of SIN and its upstream events and provided a molecular basis for SIN's potential applications in treatment of renal fibrosis-associated kidney disorders. - Highlights: • Sinomenine has strong potency of inhibiting renal fibrosis in UUO mouse kidney. • Sinomenine attenuates the expression of profibrogenic proteins. • Sinomenine balances renal fibrosis-associated oxidative stress. • Sinomenine mitigates profibrogenic

APC sets the Wnt tone necessary for cerebral cortical progenitor development.

Science.gov (United States)

Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E S

2017-08-15

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC-β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC-β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. © 2017 Nakagawa et al.; Published by Cold Spring Harbor Laboratory Press.

Hmga2 regulates self-renewal of retinal progenitors.

Science.gov (United States)

Parameswaran, Sowmya; Xia, Xiaohuan; Hegde, Ganapati; Ahmad, Iqbal

2014-11-01

In vertebrate retina, histogenesis occurs over an extended period. To sustain the temporal generation of diverse cell types, retinal progenitor cells (RPCs) must self-renew. However, self-renewal and regulation of RPCs remain poorly understood. Here, we demonstrate that cell-extrinsic factors coordinate with the epigenetic regulator high-mobility group AT-hook 2 (Hmga2) to regulate self-renewal of late retinal progenitor cells (RPCs). We observed that a small subset of RPCs was capable of clonal propagation and retained multipotentiality of parents in the presence of endothelial cells (ECs), known self-renewal regulators in various stem cell niches. The self-renewing effects, also observed in vivo, involve multiple intercellular signaling pathways, engaging Hmga2. As progenitors exhaust during retinal development, expression of Hmga2 progressively decreases. Analyses of Hmga2-expression perturbation, in vitro and in vivo, revealed that Hmga2 functionally helps to mediate cell-extrinsic influences on late-retinal progenitor self-renewal. Our results provide a framework for integrating the diverse intercellular influences elicited by epigenetic regulators for self-renewal in a dynamic stem cell niche: the developing vertebrate retina. © 2014. Published by The Company of Biologists Ltd.

Lentiviral vector-mediated genetic modification of human neural progenitor cells for ex vivo gene therapy.

Science.gov (United States)

Capowski, Elizabeth E; Schneider, Bernard L; Ebert, Allison D; Seehus, Corey R; Szulc, Jolanta; Zufferey, Romain; Aebischer, Patrick; Svendsen, Clive N

2007-07-30

Human neural progenitor cells (hNPC) hold great potential as an ex vivo system for delivery of therapeutic proteins to the central nervous system. When cultured as aggregates, termed neurospheres, hNPC are capable of significant in vitro expansion. In the current study, we present a robust method for lentiviral vector-mediated gene delivery into hNPC that maintains the differentiation and proliferative properties of neurosphere cultures while minimizing the amount of viral vector used and controlling the number of insertion sites per population. This method results in long-term, stable expression even after differentiation of the hNPC to neurons and astrocytes and allows for generation of equivalent transgenic populations of hNPC. In addition, the in vitro analysis presented predicts the behavior of transgenic lines in vivo when transplanted into a rodent model of Parkinson's disease. The methods presented provide a powerful tool for assessing the impact of factors such as promoter systems or different transgenes on the therapeutic utility of these cells.

Late acute antibody mediated rejection after nine years of renal transplantation

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Halim Medhat

2010-01-01

Full Text Available Acute Antibody Mediated Rejection (AMR is rarely reported as a long-term com-plication of renal transplantation, and it can present on top of another chronic pathology affecting the graft. A 45-year-old gentleman with chronic kidney disease due to unknown etiology received renal transplantation from his sister with 4 HLA mismatches. He received antithymocte globulin induction therapy and was maintained on steroids, azathioprine (AZA and cyclosporine A (CsA. Up to eight years post-transplantation he was clinically and biochemically stable. He lost follow-up for about one year, and then presented with nephritic nephrotic syndrome and rise of serum creatinine (SCr. to 210 μmol/L. Graft biopsy revealed picture suggestive of acute AMR on top of de novo membranoprolipherative glomerulonephritis (MPGN with focal crescent formation, diffuse immune complex deposition and peri-tubular capillaries C4d positivity. Anti-HLA donor specific antibodies were highly positive for B and T cells class I and class II. The patient was treated with intravenous immunoglobulin, plasma exchange and anti-CD20 (rituximab. AZA was changed to mycophenolate mofetil and CsA to tacrolimus. He had partial response, but SCr. continued at 220 μmol/L.

Heme-Mediated Induction of CXCL10 and Depletion of CD34+ Progenitor Cells Is Toll-Like Receptor 4 Dependent.

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Carmen M Dickinson-Copeland

Full Text Available Plasmodium falciparum infection can cause microvascular dysfunction, cerebral encephalopathy and death if untreated. We have previously shown that high concentrations of free heme, and C-X-C motif chemokine 10 (CXCL10 in sera of malaria patients induce apoptosis in microvascular endothelial and neuronal cells contributing to vascular dysfunction, blood-brain barrier (BBB damage and mortality. Endothelial progenitor cells (EPC are microvascular endothelial cell precursors partly responsible for repair and regeneration of damaged BBB endothelium. Studies have shown that EPC's are depleted in severe malaria patients, but the mechanisms mediating this phenomenon are unknown. Toll-like receptors recognize a wide variety of pathogen-associated molecular patterns generated by pathogens such as bacteria and parasites. We tested the hypothesis that EPC depletion during malaria pathogenesis is a function of heme-induced apoptosis mediated by CXCL10 induction and toll-like receptor (TLR activation. Heme and CXCL10 concentrations in plasma obtained from malaria patients were elevated compared with non-malaria subjects. EPC numbers were significantly decreased in malaria patients (P < 0.02 and TLR4 expression was significantly elevated in vivo. These findings were confirmed in EPC precursors in vitro; where it was determined that heme-induced apoptosis and CXCL10 expression was TLR4-mediated. We conclude that increased serum heme mediates depletion of EPC during malaria pathogenesis.

High circulatory leptin mediated NOX-2-peroxynitrite-miR21 axis activate mesangial cells and promotes renal inflammatory pathology in nonalcoholic fatty liver disease

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Firas Alhasson

2018-07-01

Full Text Available High circulatory insulin and leptin followed by underlying inflammation are often ascribed to the ectopic manifestations in non-alcoholic fatty liver disease (NAFLD but the exact molecular pathways remain unclear. We have shown previously that CYP2E1-mediated oxidative stress and circulating leptin in NAFLD is associated with renal disease severity. Extending the studies, we hypothesized that high circulatory leptin in NAFLD causes renal mesangial cell activation and tubular inflammation via a NOX2 dependent pathway that upregulates proinflammatory miR21. High-fat diet (60% kcal was used to induce fatty liver phenotype with parallel insulin and leptin resistance. The kidneys were probed for mesangial cell activation and tubular inflammation that showed accelerated NASH phenotype and oxidative stress in the liver. Results showed that NAFLD kidneys had significant increases in α-SMA, a marker of mesangial cell activation, miR21 levels, tyrosine nitration and renal inflammation while they were significantly decreased in leptin and p47 phox knockout mice. Micro RNA21 knockout mice showed decreased tubular immunotoxicity and proinflammatory mediator release. Mechanistically, use of NOX2 siRNA or apocynin,phenyl boronic acid (FBA, DMPO or miR21 antagomir inhibited leptin primed-miR21-mediated mesangial cell activation in vitro suggesting a direct role of leptin-mediated NOX-2 in miR21-mediated mesangial cell activation. Finally, JAK-STAT inhibitor completely abrogated the mesangial cell activation in leptin-primed cells suggesting that leptin signaling in the mesangial cells depended on the JAK-STAT pathway. Taken together the study reports a novel mechanistic pathway of leptin-mediated renal inflammation that is dependent on NOX-2-miR21 axis in ectopic manifestations underlying NAFLD-induced co-morbidities. Keywords: Leptin, NOX-2, NADPH, Mesangial cells, miR21, Oxidative stress, NAFLD, JAK/STAT, siRNA

The ERα-PI3K Cascade in Proopiomelanocortin Progenitor Neurons Regulates Feeding and Glucose Balance in Female Mice.

Science.gov (United States)

Zhu, Liangru; Xu, Pingwen; Cao, Xuehong; Yang, Yongjie; Hinton, Antentor Othrell; Xia, Yan; Saito, Kenji; Yan, Xiaofeng; Zou, Fang; Ding, Hongfang; Wang, Chunmei; Yan, Chunling; Saha, Pradip; Khan, Sohaib A; Zhao, Jean; Fukuda, Makoto; Tong, Qingchun; Clegg, Deborah J; Chan, Lawrence; Xu, Yong

2015-12-01

Estrogens act upon estrogen receptor (ER)α to inhibit feeding and improve glucose homeostasis in female animals. However, the intracellular signals that mediate these estrogenic actions remain unknown. Here, we report that anorexigenic effects of estrogens are blunted in female mice that lack ERα specifically in proopiomelanocortin (POMC) progenitor neurons. These mutant mice also develop insulin resistance and are insensitive to the glucose-regulatory effects of estrogens. Moreover, we showed that propyl pyrazole triol (an ERα agonist) stimulates the phosphatidyl inositol 3-kinase (PI3K) pathway specifically in POMC progenitor neurons, and that blockade of PI3K attenuates propyl pyrazole triol-induced activation of POMC neurons. Finally, we show that effects of estrogens to inhibit food intake and to improve insulin sensitivity are significantly attenuated in female mice with PI3K genetically inhibited in POMC progenitor neurons. Together, our results indicate that an ERα-PI3K cascade in POMC progenitor neurons mediates estrogenic actions to suppress food intake and improve insulin sensitivity.

Resveratrol induces acute endothelium-dependent renal vasodilation mediated through nitric oxide and reactive oxygen species scavenging

Science.gov (United States)

Gordish, Kevin L.

2014-01-01

Resveratrol is suggested to have beneficial cardiovascular and renoprotective effects. Resveratrol increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) synthesis. We hypothesized resveratrol acts as an acute renal vasodilator, mediated through increased NO production and scavenging of reactive oxygen species (ROS). In anesthetized rats, we found 5.0 mg/kg body weight (bw) of resveratrol increased renal blood flow (RBF) by 8% [from 6.98 ± 0.42 to 7.54 ± 0.17 ml·min−1·gram of kidney weight−1 (gkw); n = 8; P resveratrol before and after 10 mg/kg bw of the NOS inhibitor N-nitro-l-arginine methyl ester (l-NAME). l-NAME reduced the increase in RBF to resveratrol by 54% (from 0.59 ± 0.05 to 0.27 ± 0.06 ml·min−1·gkw−1; n = 10; P resveratrol before and after 1 mg/kg bw tempol, a superoxide dismutase mimetic. Resveratrol increased RBF 7.6% (from 5.91 ± 0.32 to 6.36 ± 0.12 ml·min−1·gkw−1; n = 7; P resveratrol-induced increase in RBF (from 0.45 ± 0.12 to 0.10 ± 0.05 ml·min−1·gkw−1; n = 7; P Resveratrol-induced vasodilation remained unaffected. We conclude intravenous resveratrol acts as an acute renal vasodilator, partially mediated by increased NO production/NO bioavailability and superoxide scavenging but not by inducing vasodilatory cyclooxygenase products. PMID:24431202

AKT signaling mediates IGF-I survival actions on otic neural progenitors.

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Maria R Aburto

Full Text Available BACKGROUND: Otic neurons and sensory cells derive from common progenitors whose transition into mature cells requires the coordination of cell survival, proliferation and differentiation programmes. Neurotrophic support and survival of post-mitotic otic neurons have been intensively studied, but the bases underlying the regulation of programmed cell death in immature proliferative otic neuroblasts remains poorly understood. The protein kinase AKT acts as a node, playing a critical role in controlling cell survival and cell cycle progression. AKT is activated by trophic factors, including insulin-like growth factor I (IGF-I, through the generation of the lipidic second messenger phosphatidylinositol 3-phosphate by phosphatidylinositol 3-kinase (PI3K. Here we have investigated the role of IGF-dependent activation of the PI3K-AKT pathway in maintenance of otic neuroblasts. METHODOLOGY/PRINCIPAL FINDINGS: By using a combination of organotypic cultures of chicken (Gallus gallus otic vesicles and acoustic-vestibular ganglia, Western blotting, immunohistochemistry and in situ hybridization, we show that IGF-I-activation of AKT protects neural progenitors from programmed cell death. IGF-I maintains otic neuroblasts in an undifferentiated and proliferative state, which is characterised by the upregulation of the forkhead box M1 (FoxM1 transcription factor. By contrast, our results indicate that post-mitotic p27(Kip-positive neurons become IGF-I independent as they extend their neuronal processes. Neurons gradually reduce their expression of the Igf1r, while they increase that of the neurotrophin receptor, TrkC. CONCLUSIONS/SIGNIFICANCE: Proliferative otic neuroblasts are dependent on the activation of the PI3K-AKT pathway by IGF-I for survival during the otic neuronal progenitor phase of early inner ear development.

Nuclear orphan receptor TLX induces Oct-3/4 for the survival and maintenance of adult hippocampal progenitors upon hypoxia.

Science.gov (United States)

Chavali, Pavithra Lakshminarasimhan; Saini, Ravi Kanth Rao; Matsumoto, Yoshiki; Ågren, Hans; Funa, Keiko

2011-03-18

Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia.

Nuclear Orphan Receptor TLX Induces Oct-3/4 for the Survival and Maintenance of Adult Hippocampal Progenitors upon Hypoxia*

Science.gov (United States)

Chavali, Pavithra Lakshminarasimhan; Saini, Ravi Kanth Rao; Matsumoto, Yoshiki; Ågren, Hans; Funa, Keiko

2011-01-01

Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia. PMID:21135096

Novel pathways to erythropoiesis induced by dimerization of intracellular C-Mpl in human hematopoietic progenitors.

Science.gov (United States)

Parekh, Chintan; Sahaghian, Arineh; Kim, William; Scholes, Jessica; Ge, Shundi; Zhu, Yuhua; Asgharzadeh, Shahab; Hollis, Roger; Kohn, Donald; Ji, Lingyun; Malvar, Jemily; Wang, Xiaoyan; Crooks, Gay

2012-04-01

The cytokine thrombopoietin (Tpo) plays a critical role in hematopoiesis by binding to the extracellular domain and inducing homodimerization of the intracellular signaling domain of its receptor, c-Mpl. Mpl homodimerization can also be accomplished by binding of a synthetic ligand to a constitutively expressed fusion protein F36VMpl consisting of a ligand binding domain (F36V) and the intracellular signaling domain of Mpl. Unexpectedly, in contrast to Tpo stimulation, robust erythropoiesis is induced after dimerization of F36VMpl in human CD34+ progenitor cells. The goal of this study was to define the hematopoietic progenitor stages at which dimerization of intracellular Mpl induces erythropoiesis and the downstream molecular events that mediate this unanticipated effect. Dimerization (in the absence of erythropoietin and other cytokines) in human common myeloid progenitors and megakaryocytic erythroid progenitors caused a significant increase in CD34+ cells (p Mpl in human myeloerythroid progenitors induces progenitor expansion and erythropoiesis through molecular mechanisms that are not shared by Tpo stimulation of endogenous Mpl. Copyright © 2012 AlphaMed Press.

Aging-associated inflammation promotes selection for adaptive oncogenic events in B cell progenitors.

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Henry, Curtis J; Casás-Selves, Matias; Kim, Jihye; Zaberezhnyy, Vadym; Aghili, Leila; Daniel, Ashley E; Jimenez, Linda; Azam, Tania; McNamee, Eoin N; Clambey, Eric T; Klawitter, Jelena; Serkova, Natalie J; Tan, Aik Choon; Dinarello, Charles A; DeGregori, James

2015-12-01

The incidence of cancer is higher in the elderly; however, many of the underlying mechanisms for this association remain unexplored. Here, we have shown that B cell progenitors in old mice exhibit marked signaling, gene expression, and metabolic defects. Moreover, B cell progenitors that developed from hematopoietic stem cells (HSCs) transferred from young mice into aged animals exhibited similar fitness defects. We further demonstrated that ectopic expression of the oncogenes BCR-ABL, NRAS(V12), or Myc restored B cell progenitor fitness, leading to selection for oncogenically initiated cells and leukemogenesis specifically in the context of an aged hematopoietic system. Aging was associated with increased inflammation in the BM microenvironment, and induction of inflammation in young mice phenocopied aging-associated B lymphopoiesis. Conversely, a reduction of inflammation in aged mice via transgenic expression of α-1-antitrypsin or IL-37 preserved the function of B cell progenitors and prevented NRAS(V12)-mediated oncogenesis. We conclude that chronic inflammatory microenvironments in old age lead to reductions in the fitness of B cell progenitor populations. This reduced progenitor pool fitness engenders selection for cells harboring oncogenic mutations, in part due to their ability to correct aging-associated functional defects. Thus, modulation of inflammation--a common feature of aging--has the potential to limit aging-associated oncogenesis.

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

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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.

EMMPRIN overexpression in SVZ neural progenitor cells increases their migration towards ischemic cortex.

Science.gov (United States)

Kanemitsu, Michiko; Tsupykov, Oleg; Potter, Gaël; Boitard, Michael; Salmon, Patrick; Zgraggen, Eloisa; Gascon, Eduardo; Skibo, Galina; Dayer, Alexandre G; Kiss, Jozsef Z

2017-11-01

Stimulation of endogenous neurogenesis and recruitment of neural progenitors from the subventricular zone (SVZ) neurogenic site may represent a useful strategy to improve regeneration in the ischemic cortex. Here, we tested whether transgenic overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN), the regulator of matrix metalloproteinases (MMPs) expression, in endogenous neural progenitor cells (NPCs) in the subventricular zone (SVZ) could increase migration towards ischemic injury. For this purpose, we applied a lentivector-mediated gene transfer system. We found that EMMPRIN-transduced progenitors exhibited enhanced MMP-2 activity in vitro and showed improved motility in 3D collagen gel as well as in cortical slices. Using a rat model of neonatal ischemia, we showed that EMMPRIN overexpressing SVZ cells invade the injured cortical tissue more efficiently than controls. Our results suggest that EMMPRIN overexpression could be suitable approach to improve capacities of endogenous or transplanted progenitors to invade the injured cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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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.

Acellular Mouse Kidney ECM can be Used as a Three-Dimensional Substrate to Test the Differentiation Potential of Embryonic Stem Cell Derived Renal Progenitors.

Science.gov (United States)

Sambi, Manpreet; Chow, Theresa; Whiteley, Jennifer; Li, Mira; Chua, Shawn; Raileanu, Vanessa; Rogers, Ian M

2017-08-01

The development of strategies for tissue regeneration and bio-artificial organ development is based on our understanding of embryogenesis. Differentiation protocols attempt to recapitulate the signaling modalities of gastrulation and organogenesis, coupled with cell selection regimens to isolate the cells of choice. This strategy is impeded by the lack of optimal in vitro culture systems since traditional culture systems do not allow for the three-dimensional interaction between cells and the extracellular matrix. While artificial three-dimensional scaffolds are available, using the natural extracellular matrix scaffold is advantageous because it has a distinct architecture that is difficult to replicate. The adult extracellular matrix is predicted to mediate signaling related to tissue repair not embryogenesis but existing similarities between the two argues that the extracellular matrix will influence the differentiation of stem and progenitor cells. Previous studies using undifferentiated embryonic stem cells grown directly on acellular kidney ECM demonstrated that the acellular kidney supported cell growth but limited differentiation occurred. Using mouse kidney extracellular matrix and mouse embryonic stem cells we report that the extracellular matrix can support the development of kidney structures if the stem cells are first differentiated to kidney progenitor cells before being applied to the acellular organ.

TGF-β/Smad signaling in renal fibrosis

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Xiao-Ming eMeng

2015-03-01

Full Text Available TGF-β (transforming growth factor-β is well identified as a central mediator in renal fibrosis. TGF-β initiates canonical and non-canonical pathways to exert multiple biological effects. Among them, Smad signaling is recognized as a major pathway of TGF- signaling in progressive renal fibrosis. During fibrogenesis, Smad3 is highly activated, which is associated with the down-regulation of an inhibitory Smad7 via an ubiquitin E3-ligases-dependent degradation mechanism. The equilibrium shift between Smad3 and Smad7 leads to accumulation and activation of myofibroblasts, overproduction of ECM (extracellular matrix, and reduction in ECM degradation in the diseased kidney. Therefore, overexpression of Smad7 has been shown to be a therapeutic agent for renal fibrosis in various models of kidney diseases. In contrast, another downstream effecter of TGF-β/Smad signaling pathway, Smad2, exerts its renal protective role by counter-regulating the Smad3. Furthermore, recent studies demonstrated that Smad3 mediates renal fibrosis by down-regulating miR-29 and miR-200 but up-regulating miR-21 and miR-192. Thus, overexpression of miR-29 and miR-200 or down-regulation of miR-21 and miR-192 is capable of attenuating Smad3-mediated renal fibrosis in various mouse models of chronic kidney diseases. Taken together, TGF-/Smad signaling plays an important role in renal fibrosis. Targeting TGF-β/Smad3 signaling may represent a specific and effective therapy for chronic kidney diseases associated with renal fibrosis.

Tangshen Formula Attenuates Diabetic Nephropathy by Promoting ABCA1-Mediated Renal Cholesterol Efflux in db/db Mice.

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Liu, Peng; Peng, Liang; Zhang, Haojun; Tang, Patrick Ming-Kuen; Zhao, Tingting; Yan, Meihua; Zhao, Hailing; Huang, Xiaoru; Lan, Huiyao; Li, Ping

2018-01-01

The commonly prescribed Tangshen Formula (TSF) is a traditional Chinese formulation that has been shown to reduce plasma lipid metabolism and proteinuria and improve the estimated glomerular filtration rate (eGFR) in patients with diabetic kidney disease. This study investigated the underlying mechanism whereby TSF regulates renal lipid accumulation and ameliorates diabetic renal injuries in spontaneous diabetic db/db mice and in vitro in sodium palmitate (PA)-stimulated and Abca1-SiRNA-transfected mouse tubular epithelial cells (mTECs). The results revealed that TSF treatment significantly ameliorated the renal injuries by lowering urinary albumin excretion and improving renal tissue injuries in diabetic (db/db) mice. Interestingly, the treatment with TSF also resulted in decreased cholesterol levels in the renal tissues of db/db mice, which was associated with increased expression of the peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), the Liver X receptors (LXR), and ATP-binding cassette subfamily A member 1 (ABCA1), suggesting that TSF might attenuate diabetic kidney injury via a mechanism associated with improving cholesterol efflux in the diabetic kidney. This was investigated in vitro in mTECs, and the results showed that TSF reduced the PA-stimulated cholesterol accumulation in mTECs. Mechanistically, the addition of TSF was capable of reversing PA-induced downregulation of PGC-1α, LXR, and ABCA1 expression and cholesterol accumulation in mTECs, suggesting that TSF might act the protection via the PGC-1α-LXR-ABCA1 pathway to improve the cholesterol efflux in the renal tissues of db/db mice. This was further confirmed by silencing ABCA1 to block the promotive effect of TSF on cholesterol efflux in vitro . In conclusion, TSF might ameliorate diabetic kidney injuries by promoting ABCA1-mediated renal cholesterol efflux.

Mechanisms of HO-1 mediated attenuation of renal immune injury: a gene profiling study.

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Duann, Pu; Lianos, Elias A

2011-10-01

Using a mouse model of immune injury directed against the renal glomerular vasculature and resembling human forms of glomerulonephritis (GN), we assessed the effect of targeted expression of the cytoprotective enzyme heme oxygenase (HO)-1. A human (h) HO-1 complementary DNAN (cDNA) sequence was targeted to glomerular epithelial cells (GECs) using a GEC-specific murine nephrin promoter. Injury by administration of antibody against the glomerular basement membrane (anti-GBM) to transgenic (TG) mice with GEC-targeted hHO-1 was attenuated compared with wild-type (WT) controls. To explore changes in the expression of genes that could mediate this salutary effect, we performed gene expression profiling using a microarray analysis of RNA isolated from the renal cortex of WT or TG mice with or without anti-GBM antibody-induced injury. Significant increases in expression were detected in 9 major histocompatibility complex (MHC)-class II genes, 2 interferon-γ (IFN-γ)-inducible guanosine triphosphate (GTP)ases, and 3 genes of the ubiquitin-proteasome system. The increase in MHC-class II and proteasome gene expression in TG mice with injury was validated by real-time polymerase chain reaction (PCR) or Western blot analysis. The observations point to novel mechanisms underlying the cytoprotective effect of HO-1 in renal immune injury. Copyright © 2011. Published by Mosby, Inc.

Role of bone marrow-derived stem cells, renal progenitor cells and ...

African Journals Online (AJOL)

Hayam Abdel Meguid El Aggan

2013-04-06

Apr 6, 2013 ... renal blood flow; MoAbs, monoclonal antibodies; PE, phycoerythrin;. FITC, fluorescein isothiocyanate. ... Detection of HSCs and MSCs in the peripheral blood using flow cytometry via detection of CD34, CD45, CD117 and ..... the peripheral capillary loops in 25–50% (cg2). Six biopsies showed an increase ...

SOX2 Reprograms Resident Astrocytes into Neural Progenitors in the Adult Brain

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Wenze Niu

2015-05-01

Full Text Available Glial cells can be in vivo reprogrammed into functional neurons in the adult CNS; however, the process by which this reprogramming occurs is unclear. Here, we show that a distinct cellular sequence is involved in SOX2-driven in situ conversion of adult astrocytes to neurons. This includes ASCL1+ neural progenitors and DCX+ adult neuroblasts (iANBs as intermediates. Importantly, ASCL1 is required, but not sufficient, for the robust generation of iANBs in the adult striatum. These progenitor-derived iANBs predominantly give rise to calretinin+ interneurons when supplied with neurotrophic factors or the small-molecule valproic acid. Patch-clamp recordings from the induced neurons reveal subtype heterogeneity, though all are functionally mature, fire repetitive action potentials, and receive synaptic inputs. Together, these results show that SOX2-mediated in vivo reprogramming of astrocytes to neurons passes through proliferative intermediate progenitors, which may be exploited for regenerative medicine.

Valsartan reduces AT1-AA-induced apoptosis through suppression oxidative stress mediated ER stress in endothelial progenitor cells.

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Wang, Z-C; Qi, J; Liu, L-M; Li, J; Xu, H-Y; Liang, B; Li, B

2017-03-01

Valsartan has been reported to have the function of treating hypertension and improving the prognosis of patients. Many studies indicated that valsartan can also increase angiotensin II, andosterone and plasma renin activity (PRA). Autoantibodies against the angiotensin II type 1 receptor (AT1-AA) have been showed to increase reactive oxygen species (ROS) and calcium (Ca2+) and result in apoptosis in vascular smooth muscle cells. In this study, we attempted to explore the effect of valsartan on AT1-AA-induced apoptosis in endothelial progenitor cells. Endothelial progenitor cells (EPCs) were cultured. The cytotoxicity was determined by MTT assay. EPCs apoptosis was determined by DAPI staining and flow cytometry. Reactive oxygen species, intracellular calcium concentration and calpain activity were measured using Fluostar Omega Spectrofluorimeter. The expression of p-ERK, p-eIF-2a, CHOP, Bcl-2 and caspase-3 were detected by Western blot. MTT assays showed valsartan significantly inhibited AT1-AA- induced decline of the viability of EPCs. DAPI staining and flow cytometry results indicated valsartan inhibited AT1-AA-induced decline of the viability of EPCs via inhibiting AT1-AA-induced apoptosis. Furthermore, the increasing of reactive oxygen species, intracellular calcium and calpain activity induced by AT1-AA in EPCs were also recovered after pre-treated with valsartan. Meanwhile, the upregulation of p-ERK, p-eIF-2a and CHOP, downregulation of Bcl-2, and activation of Caspase-3 caused by AT1-AA were reversed after pre-incubated with valsartan. Valsartan could inhibit AT1-AA-induced apoptosis through inhibiting oxidative stress mediated ER stress in EPCs.

NO-independent mechanism mediates tempol-induced renal vasodilation in SHR

DEFF Research Database (Denmark)

de Richelieu, Louise Tilma; Sørensen, Charlotte Mehlin; Salomonsson, Max

2005-01-01

whether the effects of tempol were due to a restored NO system, we used the NOS inhibitor N(w)-nitro-L-arginine methyl ester (L-NAME). Renal blood flow (RBF) and mean arterial pressure (MAP) were measured in vivo by electromagnetic flowmetry and arterial catheterization in 10- to 12-wk-old anesthetized......We investigated whether tempol, a superoxide dismutase mimetic, affected renal hemodynamics and arterial pressure in spontaneously hypertensive rats (SHR) and Sprague-Dawley (SD) rats. We also examined whether tempol affected exaggerated renal vasoconstrictor responses to ANG II in SHR. To test...... used as controls. ANG II (1-4 ng) was administered as a bolus via a renal artery catheter. L-NAME was administered intravenously for 15-20 min. Renal vascular resistance (RVR) was elevated in SHR-C compared with SD-C. In SHR-T, baseline RVR was not different from SD-C and SD-T rats. Tempol had...

Reviewing the pathogenesis of antibody-mediated rejection and renal graft pathology after kidney transplantation.

Science.gov (United States)

Morozumi, Kunio; Takeda, Asami; Otsuka, Yasuhiro; Horike, Keiji; Gotoh, Norihiko; Narumi, Shunji; Watarai, Yoshihiko; Kobayashi, Takaaki

2016-07-01

The clinicopathological context of rejection after kidney transplantation was well recognized. Banff conferences greatly contributed to elucidate the pathogenesis and to establish the pathologic criteria of rejection after kidney transplantation. The most important current problem of renal transplantation is de novo donor-specific antibody (DSA) production leading chronic rejection and graft loss. Microvascular inflammation is considered as a reliable pathological marker for antibody-mediated rejection (AMR) in the presence of DSA. Electron microscopic study allowed us to evaluate early changes in peritubular capillaries in T-lymphocyte mediated rejection and transition to antibody-mediated rejection. Severe endothelial injuries with edema and activated lymphocyte invaded into subendothelial space with early multi-layering of peritubular capillary basement membrane suggest T-lymphocyte mediated rejection induce an unbounded chain of antibody-mediated rejection. The risk factors of AMR after ABO-incompatible kidney transplantation are important issues. Anti-ABO blood type antibody titre of IgG excess 32-fold before transplant operation is the only predictable factor for acute AMR. Characteristics of chronic active antibody-mediated rejection (CAAMR) are one of the most important problems. Light microscopic findings and C4d stain of peritubular capillary and glomerular capillary are useful diagnostic criteria of CAAMR. Microvascular inflammation, double contour of glomerular capillary and thickening of peritubular capillary basement are good predictive factors of the presence of de novo DSA. C4d stain of linear glomerular capillary is a more sensitive marker for CAAMR than positive C4d of peritubular capillary. Early and sensitive diagnostic attempts of diagnosing CAAMR are pivotal to prevent chronic graft failure. © 2016 Asian Pacific Society of Nephrology.

Nuclear Orphan Receptor TLX Induces Oct-3/4 for the Survival and Maintenance of Adult Hippocampal Progenitors upon Hypoxia*

OpenAIRE

Chavali, Pavithra Lakshminarasimhan; Saini, Ravi Kanth Rao; Matsumoto, Yoshiki; Ågren, Hans; Funa, Keiko

2010-01-01

Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with c...

Epigenetic Reprogramming of Muscle Progenitors: Inspiration for Clinical Therapies

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Silvia Consalvi

2016-01-01

Full Text Available In the context of regenerative medicine, based on the potential of stem cells to restore diseased tissues, epigenetics is becoming a pivotal area of interest. Therapeutic interventions that promote tissue and organ regeneration have as primary objective the selective control of gene expression in adult stem cells. This requires a deep understanding of the epigenetic mechanisms controlling transcriptional programs in tissue progenitors. This review attempts to elucidate the principle epigenetic regulations responsible of stem cells differentiation. In particular we focus on the current understanding of the epigenetic networks that regulate differentiation of muscle progenitors by the concerted action of chromatin-modifying enzymes and noncoding RNAs. The novel exciting role of exosome-bound microRNA in mediating epigenetic information transfer is also discussed. Finally we show an overview of the epigenetic strategies and therapies that aim to potentiate muscle regeneration and counteract the progression of Duchenne Muscular Dystrophy (DMD.

Inhibiting aerobic glycolysis suppresses renal interstitial fibroblast activation and renal fibrosis.

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Ding, Hao; Jiang, Lei; Xu, Jing; Bai, Feng; Zhou, Yang; Yuan, Qi; Luo, Jing; Zen, Ke; Yang, Junwei

2017-09-01

Chronic kidney diseases generally lead to renal fibrosis. Despite great progress having been made in identifying molecular mediators of fibrosis, the mechanism that governs renal fibrosis remains unclear, and so far no effective therapeutic antifibrosis strategy is available. Here we demonstrated that a switch of metabolism from oxidative phosphorylation to aerobic glycolysis (Warburg effect) in renal fibroblasts was the primary feature of fibroblast activation during renal fibrosis and that suppressing renal fibroblast aerobic glycolysis could significantly reduce renal fibrosis. Both gene and protein assay showed that the expression of glycolysis enzymes was upregulated in mouse kidneys with unilateral ureter obstruction (UUO) surgery or in transforming growth factor-β1 (TGF-β1)-treated renal interstitial fibroblasts. Aerobic glycolysis flux, indicated by glucose uptake and lactate production, was increased in mouse kidney with UUO nephropathy or TGF-β1-treated renal interstitial fibroblasts and positively correlated with fibrosis process. In line with this, we found that increasing aerobic glycolysis can remarkably induce myofibroblast activation while aerobic glycolysis inhibitors shikonin and 2-deoxyglucose attenuate UUO-induced mouse renal fibrosis and TGF-β1-stimulated myofibroblast activation. Furthermore, mechanistic study indicated that shikonin inhibits renal aerobic glycolysis via reducing phosphorylation of pyruvate kinase type M2, a rate-limiting glycolytic enzyme associated with cell reliance on aerobic glycolysis. In conclusion, our findings demonstrate the critical role of aerobic glycolysis in renal fibrosis and support treatment with aerobic glycolysis inhibitors as a potential antifibrotic strategy. Copyright © 2017 the American Physiological Society.

Estradiol-induced, endothelial progenitor cell-mediated neovascularization in male mice with hind-limb ischemia

NARCIS (Netherlands)

Ruifrok, Willem-Peter T.; de Boer, Rudolf A.; Iwakura, Atsushi; Silver, Marcy; Kusano, Kengo; Tio, Rene A.; Losordo, Douglas W.

We investigated whether administration of estradiol to male mice augments mobilization of bone marrow-derived endothelial progenitor cells (EPC) and incorporation into foci of neovascularization after hind-limb ischemia, thereby contributing to blood flow restoration. Mice were randomized and

Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs.

Science.gov (United States)

Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

2016-03-21

In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Renal damage mediated by oxidative stress: a hypothesis of protective effects of red wine.

Science.gov (United States)

Rodrigo, Ramón; Rivera, Gonzalo

2002-08-01

Over the last decade, oxidative stress has been implicated in the pathogenesis of a wide variety of seemingly unrelated renal diseases. Epidemiological studies have documented an association of moderate wine consumption with a decreased risk of cardiovascular and neurological diseases; however, similar studies in the kidney are still lacking. The kidney is an organ highly vulnerable to damage caused by reactive oxygen species (ROS), likely due to the abundance of polyunsaturated fatty acids in the composition of renal lipids. ROS are involved in the pathogenic mechanism of conditions such as glomerulosclerosis and tubulointerstitial fibrosis. The health benefits of moderate consumption of red wine can be partly attributed to its antioxidant properties. Indeed, the kidney antioxidant defense system is enhanced after chronic exposure to moderate amounts of wine, a response arising from the combined effects of ethanol and the nonalcoholic components, mainly polyphenols. Polyphenols behave as potent ROS scavengers and metal chelators; ethanol, in turn, modulates the activity of antioxidant enzymes. Therefore, a hypothesis that red wine causes a decreased vulnerability of the kidney to the oxidative challenges could be proposed. This view is partly supported by direct evidences indicating that wine and antioxidants isolated from red wine, as well as other antioxidants, significantly attenuate or prevent the oxidative damage to the kidney. The present hypothesis paper provides a collective body of evidence suggesting a protective role of moderate wine consumption against the production and progression of renal diseases, based on the existing concepts on the pathophysiology of kidney injury mediated by oxidative stress.

Neural regulation of the kidney function in rats with cisplatin induced renal failure

Science.gov (United States)

Goulding, Niamh E.; Johns, Edward J.

2015-01-01

Aim: Chronic kidney disease (CKD) is often associated with a disturbed cardiovascular homeostasis. This investigation explored the role of the renal innervation in mediating deranged baroreflex control of renal sympathetic nerve activity (RSNA) and renal excretory function in cisplatin-induced renal failure. Methods: Rats were either intact or bilaterally renally denervated 4 days prior to receiving cisplatin (5 mg/kg i.p.) and entered a chronic metabolic study for 8 days. At day 8, other groups of rats were prepared for acute measurement of RSNA or renal function with either intact or denervated kidneys. Results: Following the cisplatin challenge, creatinine clearance was 50% lower while fractional sodium excretion and renal cortical and medullary TGF-β1 concentrations were 3–4 fold higher in both intact and renally denervated rats compared to control rats. In cisplatin-treated rats, the maximal gain of the high-pressure baroreflex curve was only 20% that of control rats, but following renal denervation not different from that of renally denervated control rats. Volume expansion reduced RSNA by 50% in control and in cisplatin-treated rats but only following bilateral renal denervation. The volume expansion mediated natriuresis/diuresis was absent in the cisplatin-treated rats but was normalized following renal denervation. Conclusions: Cisplatin-induced renal injury impaired renal function and caused a sympatho-excitation with blunting of high and low pressure baroreflex regulation of RSNA, which was dependent on the renal innervation. It is suggested that in man with CKD there is a dysregulation of the neural control of the kidney mediated by its sensory innervation. PMID:26175693

Complement C5a-C5aR interaction enhances MAPK signaling pathway activities to mediate renal injury in trichloroethylene sensitized BALB/c mice.

Science.gov (United States)

Zhang, Jia-xiang; Zha, Wan-sheng; Ye, Liang-ping; Wang, Feng; Wang, Hui; Shen, Tong; Wu, Chang-hao; Zhu, Qi-xing

2016-02-01

We have previously shown complement activation as a possible mechanism for trichloroethylene (TCE) sensitization, leading to multi-organ damage including the kidneys. In particular, excessive deposition of C5 and C5b-9-the membrane attack complex, which can generate significant tissue damage, was observed in the kidney tissue after TCE sensitization. The present study tested the hypothesis that anaphylatoxin C5a binding to its receptor C5aR mediates renal injury in TCE-sensitized BALB/c mice. BALB/c mice were sensitized through skin challenge with TCE, with or without pretreatment by the C5aR antagonist W54011. Kidney histopathology and the renal functional test were performed to assess renal injury, and immunohistochemistry and fluorescent labeling were carried out to assess C5a and C5aR expressions. TCE sensitization up-regulated C5a and C5aR expressions in kidney tissue, generated inflammatory infiltration, renal tubule damage, glomerular hypercellularity and impaired renal function. Antagonist pretreatment blocked C5a binding to C5aR and attenuated TCE-induced tissue damage and renal dysfunction. TCE sensitization also caused the deposition of major pro-inflammatory cytokines IL-2, TNF-α and IFN-γ in the kidney tissue (P < 0.05); this was accompanied by increased expression of P-p38, P-ERK and P-JNK proteins (P < 0.05). Pretreatment with the C5aR antagonist attenuated the increase of expression of P-p38, P-ERK and P-JNK proteins (P < 0.05) and also consistently reduced the TCE sensitization-induced increase of IL-2, TNF-α and IFN-γ (P < 0.05). These data identify C5a binding to C5aR, MAP kinase activation, and inflammatory cytokine release as a novel mechanism for complement-mediated renal injury by sensitization with TCE or other environmental chemicals. Copyright © 2015 John Wiley & Sons, Ltd.

Erythropoietin Receptor Positive Circulating Progenitor Cells and Endothelial Progenitor Cells in Patients with Different Stages of Diabetic Retinopathy

Institute of Scientific and Technical Information of China (English)

Liu-mei Hu; Guo-xu Xu; Guo-tong XU; Wei-ye Li; Xia Lei; Bo Ma; Yu Zhang; Yan Yan; Ya-lan Wu; Ge-zhi Xu; Wen Ye; Ling Wang

2011-01-01

Objective To investigate the possible involvement of erythropoietin (EPO)/erythropoietin receptor(EPOR) system in neovascularization and vascular regeneration in diabetic retinopathy (DR).Methods EPOR positive circulating progenitor cells (CPCs: CD34+) and endothelial progenitor cells (EPCs: CD34+KDR+) were assessed by flow cytometry in type 2 diabetic patients with different stages of DR. The cohort consisted of age- and sex-matched control patients without diabetes (n=7), non-prolif-erative DR (NPDR, n=7), proliferative DR (PDR, n=8), and PDR complicated with diabetic nephropathy (PDR-DN, n=7). Results The numbers of EPOR+ CPCs and EPOR+ EPCs were reduced remarkably in NPDR compared with the control group (both P<0.01), whereas rebounded in PDR and PDR-DN groups in varying degrees. Similar changes were observed in respect of the proportion of EPOR+ CPCs in CPCs (NPDR vs.control, P< 0.01) and that of EPOR+ EPCs in EPCs (NPDR vs. control, P< 0.05). Conclusion Exogenous EPO, mediated via the EPO/EPOR system of EPCs, may alleviate the im-paired vascular regeneration in NPDR, whereas it might aggravate retinal neovascularization in PDR due to a rebound of EPOR+ EPCs associated with ischemia.

Effect of mitochondrial potassium channel on the renal protection mediated by sodium thiosulfate against ethylene glycol induced nephrolithiasis in rat model

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N. Baldev

2015-12-01

Full Text Available Purpose: Sodium thiosulfate (STS is clinically reported to be a promising drug in preventing nephrolithiasis. However, its mechanism of action remains unclear. In the present study, we investigated the role of mitochondrial KATP channel in the renal protection mediated by STS. Materials and Methods: Nephrolithiasis was induced in Wistar rats by administrating 0.4% ethylene glycol (EG along with 1% ammonium chloride for one week in drinking water followed by only 0.75% EG for two weeks. Treatment groups received STS, mitochondrial KATP channel opener and closer exclusively or in combination with STS for two weeks. Results: Animals treated with STS showed normal renal tissue architecture, supported by near normal serum creatinine, urea and ALP activity. Diazoxide (mitochondria KATP channel opening treatment to the animal also showed normal renal tissue histology and improved serum chemistry. However, an opposite result was shown by glibenclamide (mitochondria KATP channel closer treated rats. STS administered along with diazoxide negated the renal protection rendered by diazoxide alone, while it imparted protection to the glibenclamide treated rats, formulating a mitochondria modulated STS action. Conclusion: The present study confirmed that STS render renal protection not only through chelation and antioxidant effect but also by modulating the mitochondrial KATP channel for preventing urolithiasis.

Renal deterioration caused by carcinogens as a consequence of free radical mediated tissue damage: a review of the protective action of melatonin

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Gultekin, Fatih; Hicyilmaz, Hicran [Suleyman Demirel University, School of Medicine, Department of Biochemistry, Isparta (Turkey)

2007-10-15

This brief review summarizes some of the publications that document the preventive role of melatonin in kidney damage caused by carcinogens such as 2-nitropropane, arsenic, carbon tetrachloride, nitrilotriacetic acid and potassium bromate. Numerous chemicals generate excessive free radicals that eventually induce renal worsening. Melatonin partially or totally prevents free radical mediated tissue damages induced by many carcinogens. Protective actions of melatonin against the harmful effects of carcinogens are believed to stem from its direct free radical scavenging and indirect antioxidant activities. Dietary or pharmacologically given melatonin may attenuate the oxidative stress, thereby mitigating the subsequent renal damage. (orig.)

A quantitative analysis on the interfacial effect in the Pt/Ba0.5Sr0.5TiO3/La0.67Sr0.33MnO3 heterostructure

International Nuclear Information System (INIS)

Miao, J; Wang, Y; Tian, H Y; Zhou, X Y; Chan, H L W; Choy, C L; Cao, L X; Zhao, B R

2006-01-01

The heterostructure of Pt/Ba 0.5 Sr 0.5 TiO 3 /La 0.67 Sr 0.33 MnO 3 (Pt/BST/LSMO) with the BST thickness ranging from 120 to 550 nm was fabricated by pulsed laser deposition. The dielectric constant (ε) of the heterostructure was measured under different electrical fields (E) and frequency (f). A strong thickness dependence of the value of ε, the ε-E dependence and the ε-f dependence were observed, which can be well explained by the series-capacitor model, based on the assumption that the heterostructure electrically consists of a 'bulk' layer and an interfacial layer between the Pt and BST layers. The dielectric properties of the 'bulk' layer and the interface layer were obtained. At room temperature, the dielectric constant of the 'bulk' layer was 1204 (at 100 kHz) and had a power law dependence on frequency. The ratio of thickness over the dielectric constant (d i /ε i ) of the interface layer, which was used to characterize the property of the Pt/BST interface, was found to be around 0.08 nm at room temperature and to be independent of frequency

Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status.

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Wang, Naitao; Dong, Bai-Jun; Quan, Yizhou; Chen, Qianqian; Chu, Mingliang; Xu, Jin; Xue, Wei; Huang, Yi-Ran; Yang, Ru; Gao, Wei-Qiang

2016-05-10

Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS) in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3) was upregulated in a large subset of benign prostatic hyperplasia (BPH) tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status

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Naitao Wang

2016-05-01

Full Text Available Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3 was upregulated in a large subset of benign prostatic hyperplasia (BPH tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH.

Correction of glucocerebrosidase deficiency after retroviral-mediated gene transfer into hematopoietic progenitor cells from patients with Gaucher disease

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Fink, J.K.; Correll, P.H.; Perry, L.K.; Brady, R.O.; Karlsson, S.

1990-01-01

Retroviral gene transfer has been used successfully to correct the glucocerebrosidase (GCase) deficiency in primary hematopoietic cells from patients with Gaucher disease. For this model of somatic gene therapy, the authors developed a high-titer, amphotropic retroviral vector designated NTG in which the human GCase gene was driven by the mutant polyoma virus enhancer/herpesvirus thymidine kinase gene (tk) promoter (Py + /Htk). NTG normalized GCase activity in transduced Gaucher fibroblasts and efficiently infected human monocytic and erythroleukemic cell lines. RNA blot-hybridization (Northern blot) analysis of these hemaptopoietic cell lines showed unexpectedly high-level expression from the Moloney murine leukemia virus long terminal repeat (Mo-MLV LTR) and levels of Py + /Htk enhancer/promoter-initiated human GCase RNA that approximated endogenous GCase RNA levels. Furthermore, NTG efficiently infected human hematopoietic progenitor cells. Detection of the provirus in approximately one-third of NTG-infected progenitor colonies that had not been selected in G418-containing medium indicates that relative resistance to G418 underestimated the actual gene transfer efficiency. Northern blot analysis of NTG-infected, progenitor-derived cells showed expression from both the Mo-MLV LTR and the Py + /Htk enhancer/promoter. NTG-transduced hematopoietic progenitor cells from patients with Gaucher disease generated progeny in which GCase activity has been normalized

Correction of glucocerebrosidase deficiency after retroviral-mediated gene transfer into hematopoietic progenitor cells from patients with Gaucher disease

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Fink, J.K.; Correll, P.H.; Perry, L.K.; Brady, R.O.; Karlsson, S. (National Institutes of Health, Bethesda, MD (USA))

1990-03-01

Retroviral gene transfer has been used successfully to correct the glucocerebrosidase (GCase) deficiency in primary hematopoietic cells from patients with Gaucher disease. For this model of somatic gene therapy, the authors developed a high-titer, amphotropic retroviral vector designated NTG in which the human GCase gene was driven by the mutant polyoma virus enhancer/herpesvirus thymidine kinase gene (tk) promoter (Py{sup +}/Htk). NTG normalized GCase activity in transduced Gaucher fibroblasts and efficiently infected human monocytic and erythroleukemic cell lines. RNA blot-hybridization (Northern blot) analysis of these hemaptopoietic cell lines showed unexpectedly high-level expression from the Moloney murine leukemia virus long terminal repeat (Mo-MLV LTR) and levels of Py{sup +}/Htk enhancer/promoter-initiated human GCase RNA that approximated endogenous GCase RNA levels. Furthermore, NTG efficiently infected human hematopoietic progenitor cells. Detection of the provirus in approximately one-third of NTG-infected progenitor colonies that had not been selected in G418-containing medium indicates that relative resistance to G418 underestimated the actual gene transfer efficiency. Northern blot analysis of NTG-infected, progenitor-derived cells showed expression from both the Mo-MLV LTR and the Py{sup +}/Htk enhancer/promoter. NTG-transduced hematopoietic progenitor cells from patients with Gaucher disease generated progeny in which GCase activity has been normalized.

Mesenchymal progenitor cells for the osteogenic lineage.

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Ono, Noriaki; Kronenberg, Henry M

2015-09-01

Mesenchymal progenitors of the osteogenic lineage provide the flexibility for bone to grow, maintain its function and homeostasis. Traditionally, colony-forming-unit fibroblasts (CFU-Fs) have been regarded as surrogates for mesenchymal progenitors; however, this definition cannot address the function of these progenitors in their native setting. Transgenic murine models including lineage-tracing technologies based on the cre-lox system have proven to be useful in delineating mesenchymal progenitors in their native environment. Although heterogeneity of cell populations of interest marked by a promoter-based approach complicates overall interpretation, an emerging complexity of mesenchymal progenitors has been revealed. Current literatures suggest two distinct types of bone progenitor cells; growth-associated mesenchymal progenitors contribute to explosive growth of bone in early life, whereas bone marrow mesenchymal progenitors contribute to the much slower remodeling process and response to injury that occurs mainly in adulthood. More detailed relationships of these progenitors need to be studied through further experimentation.

In Situ Malignant Transformation and Progenitor-Mediated Cell Budding: Two Different Pathways for Breast Ductal and Lobular Tumor Invasion

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Yan-gao Man, Mina Izadjoo, Guohong Song, Alexander Stojadinovic

2011-01-01

Full Text Available The human breast lobular and ductal structures and the derived tumors from these structures differ substantial in their morphology, microenvironment, biological presentation, functions, and clinical prognosis. Based on these differences, we have proposed that pre-invasive lobular tumors may progress to invasive lesions through “in situ malignant transformation”, in which the entire myoepithelial cell layer within a given lobule or lobular clusters undergoes extensive degeneration and disruptions, which allows the entire epithelial cell population associated with these myoepithelial cell layers directly invade the stroma or vascular structures. In contrast, pre-invasive ductal tumors may invade the stroma or vascular structures through “progenitor-mediated cell budding”, in which focal myoepithelial cell degeneration-induced aberrant leukocyte infiltration causes focal disruptions in the tumor capsules, which selectively favor monoclonal proliferation of the overlying tumor stem cells or a biologically more aggressive cell clone. Our current study attempted to provide more direct morphological and immunohistochemical data that are consistent with our hypotheses.

Advanced glycation endproducts alter functions and promote apoptosis in endothelial progenitor cells through receptor for advanced glycation endproducts mediate overpression of cell oxidant stress.

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Chen, Jianfei; Song, Minbao; Yu, Shiyong; Gao, Pan; Yu, Yang; Wang, Hong; Huang, Lan

2010-02-01

Endothelial progenitor cells (EPCs) play an important role in preventing atherosclerosis. The factors that regulate the function of EPCs are not completely clear. Increased formation of advanced glycation endproducts (AGEs) is generally regarded as one of the main mechanisms responsible for vascular damage in patients with diabetes and atherosclerosis. AGEs lead to the generation of reactive oxygen species (ROS) and part of the regenerative capacity of EPCs seems to be due to their low baseline ROS levels and reduced sensitivity to ROS-induced cell apoptosis. Therefore, we tested the hypothesis that AGEs can alter functions and promote apoptosis in EPCs through overpress cell oxidant stress. EPCs, isolated from bone marrow, were cultured in the absence or presence of AGEs (50, 100, and 200 microg/ml). A modified Boyden's chamber was used to assess the migration of EPCs and the number of recultured EPCs was counted to measure the adhesiveness function. MTT assay was used to determine the proliferation function. ROS were analyzed using the ROS assay kit. A spectrophotometer was used to assess superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, and PCR was used to test mRNA expression of SOD and GSH-PX. SiRNA was used to block receptor for advanced glycation endproducts (RAGEs) expression. Apoptosis was evaluated by Annexin V immunostaining and TUNEL staining. Co-culturing with AGEs increases ROS production, decreases anti-oxidant defenses, overpresses oxidant stress, inhibits the proliferation, migration, and adhesion of EPCs, and induces EPCs apoptosis. In addition, these effects were attenuated during block RAGE protein expression by siRNA. AGEs may serve to impair EPCs functions through RAGE-mediate oxidant stress, and promote EPCs sensitivity toward oxidative-stress-mediated apoptosis, which indicates a new pathophysiological mechanism of disturbed vascular adaptation in atherosclerosis and suggests that lower levels of AGEs might improve the

Periodontal Bioengineering: A Discourse in Surface Topographies, Progenitor Cells and Molecular Profiles

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Dangaria, Smit J.

2011-12-01

Stem/progenitor cells are a population of cells capable of providing replacement cells for a given differentiated cell type. We have applied progenitor cell-based technologies to generate novel tissue-engineered implants that use biomimetic strategies with the ultimate goal of achieving full regeneration of lost periodontal tissues. Mesenchymal periodontal tissues such as cementum, alveolar bone (AB), and periodontal ligament (PDL) are neural crest-derived entities that emerge from the dental follicle (DF) at the onset of tooth root formation. Using a systems biology approach we have identified key differences between these periodontal progenitors on the basis of global gene expression profiles, gene cohort expression levels, and epigenetic modifications, in addition to differences in cellular morphologies. On an epigenetic level, DF progenitors featured high levels of the euchromatin marker H3K4me3, whereas PDL cells, AB osteoblasts, and cementoblasts contained high levels of the transcriptional repressor H3K9me3. Secondly, we have tested the influence of natural extracellular hydroxyapatite matrices on periodontal progenitor differentiation. Dimension and structure of extracellular matrix surfaces have powerful influences on cell shape, adhesion, and gene expression. Here we show that natural tooth root topographies induce integrin-mediated extracellular matrix signaling cascades in tandem with cell elongation and polarization to generate physiological periodontium-like tissues. In this study we replanted surface topography instructed periodontal ligament progenitors (PDLPs) into rat alveolar bone sockets for 8 and 16 weeks, resulting in complete attachment of tooth roots to the surrounding alveolar bone with a periodontal ligament fiber apparatus closely matching physiological controls along the entire root surface. Displacement studies and biochemical analyses confirmed that progenitor-based engineered periodontal tissues were similar to control teeth and

Spontaneous calcium transients in human neural progenitor cells mediated by transient receptor potential channels.

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Morgan, Peter J; Hübner, Rayk; Rolfs, Arndt; Frech, Moritz J

2013-09-15

Calcium signals affect many developmental processes, including proliferation, migration, survival, and apoptosis, processes that are of particular importance in stem cells intended for cell replacement therapies. The mechanisms underlying Ca(2+) signals, therefore, have a role in determining how stem cells respond to their environment, and how these responses might be controlled in vitro. In this study, we examined the spontaneous Ca(2+) activity in human neural progenitor cells during proliferation and differentiation. Pharmacological characterization indicates that in proliferating cells, most activity is the result of transient receptor potential (TRP) channels that are sensitive to Gd(3+) and La(3+), with the more subtype selective antagonist Ruthenium red also reducing activity, suggesting the involvement of transient receptor potential vanilloid (TRPV) channels. In differentiating cells, Gd(3+) and La(3+)-sensitive TRP channels also appear to underlie the spontaneous activity; however, no sub-type-specific antagonists had any effect. Protein levels of TRPV2 and TRPV3 decreased in differentiated cells, which is demonstrated by western blot. Thus, it appears that TRP channels represent the main route of Ca(2+) entry in human neural progenitor cells (hNPCs), but the responsible channel types are subject to substitution under differentiating conditions. The level of spontaneous activity could be increased and decreased by lowering and raising the extracellular K(+) concentration. Proliferating cells in low K(+) slowed the cell cycle, with a disproportionate increased percentage of cells in G1 phase and a reduction in S phase. Taken together, these results suggest a link between external K(+) concentration, spontaneous Ca(2+) transients, and cell cycle distribution, which is able to influence the fate of stem and progenitor cells.

Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport

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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.

Macrophage-Mediated Lymphangiogenesis: The Emerging Role of Macrophages as Lymphatic Endothelial Progenitors

International Nuclear Information System (INIS)

Ran, Sophia; Montgomery, Kyle E.

2012-01-01

It is widely accepted that macrophages and other inflammatory cells support tumor progression and metastasis. During early stages of neoplastic development, tumor-infiltrating macrophages (TAMs) mount an immune response against transformed cells. Frequently, however, cancer cells escape the immune surveillance, an event that is accompanied by macrophage transition from an anti-tumor to a pro-tumorigenic type. The latter is characterized by high expression of factors that activate endothelial cells, suppress immune response, degrade extracellular matrix, and promote tumor growth. Cumulatively, these products of TAMs promote tumor expansion and growth of both blood and lymphatic vessels that facilitate metastatic spread. Breast cancers and other epithelial malignancies induce the formation of new lymphatic vessels (i.e., lymphangiogenesis) that leads to lymphatic and subsequently, to distant metastasis. Both experimental and clinical studies have shown that TAMs significantly promote tumor lymphangiogenesis through paracrine and cell autonomous modes. The paracrine effect consists of the expression of a variety of pro-lymphangiogenic factors that activate the preexisting lymphatic vessels. The evidence for cell-autonomous contribution is based on the observed tumor mobilization of macrophage-derived lymphatic endothelial cell progenitors (M-LECP) that integrate into lymphatic vessels prior to sprouting. This review will summarize the current knowledge of macrophage-dependent growth of new lymphatic vessels with specific emphasis on an emerging role of macrophages as lymphatic endothelial cell progenitors (M-LECP)

Circulating angiotensin type II receptor: Possible marker for antibody mediated rejection after renal transplantation?

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Kimball, Pamela M; Gupta, Gaurav; McDougan, Felecia

2017-10-01

Presence of antibody [Ab] against angiotensin receptor [AT1R] indicates heightened risk for antibody mediated rejection [AMR] after transplantation but is insufficient as a marker. We speculated AT1R might be released systemically because of AMR and might be a useful biomarker. AT1R was measured in blood from 73 Normals and 72 renal patients pre- and post-transplantation. Patients were stratified as AMR-free [Gp1], AMR1yr [Gp3]. AT1R was higher [13±26vs.367±537, p<0.01)] and more prevalent [20% vs. 92%, p<0.01] among renal patients than Normals. Pretransplant levels were similar [p=ns] between groups. One-year posttransplant levels approached [p<0.01] normalcy for Gps1+3 but spiked during AMR and remained elevated [155±58, p<0.01] for 50% Gp2 patients. One-year AT1R levels were higher among subsequent graft failures than surviving grafts [171±267vs. 38±50, p<0.01]. Pretransplant AT1R was abnormally elevated: possibly indicating ongoing tissue injury. Pretransplant AT1R didn't predict risk for AMR. However, AT1R spiked during early AMR and sustained elevations were associated with poorer outcomes. Copyright © 2017. Published by Elsevier Inc.

Smoking decreases the level of circulating CD34+ progenitor cells in young healthy women - a pilot study

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Baumann Gert

2010-05-01

Full Text Available Abstract Background Decreased levels of circulating bone marrow-derived progenitor cells have been associated with risk factors and cardiovascular diseases. Smoking is the most important modifiable risk factor for atherosclerosis in young women. The aim of this pilot study was to assess in healthy premenopausal women without other risk factors for cardiovascular disease the influence of nicotine abuse on the number of circulating progenitor cells in relation to endothelial function. Methods The number of endothelial progenitor cells, measured as colony-forming units in a cell-culture assay (EPC-CFU and the number of circulating CD34 + and CD34 + /CD133 + cells, measured by flow cytometry, was estimated in 32 women at the menstrual phase of the menstrual cycle. In addition, flow-mediated dilation (FMD was assessed as a marker for vascular function. In a subgroup of these women (n = 20, progenitor cells were also investigated at the mid-follicular and luteal phases of the menstrual cycle. Results Compared to non-smokers, the abundance of circulating CD34 + cells was significantly lower in smoking women in the menstrual, mid-luteal, and mid-follicular phases of the menstrual cycle. The number of CD34 + progenitor cells was revealed to have significant positive correlation with FMD in young healthy women, whereas CD34 + /CD133 + progenitor cells and EPC-CFU showed no significant correlation. Conclusion The number of CD34 + progenitor cells positively correlates with FMD in young healthy women and is decreased by smoking.

Hibiscus sabdariffa polyphenols prevent palmitate-induced renal epithelial mesenchymal transition by alleviating dipeptidyl peptidase-4-mediated insulin resistance.

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Huang, Chien-Ning; Wang, Chau-Jong; Yang, Yi-Sun; Lin, Chih-Li; Peng, Chiung-Huei

2016-01-01

Diabetic nephropathy has a significant socioeconomic impact, but its mechanism is unclear and needs to be examined. Hibiscus sabdariffa polyphenols (HPE) inhibited high glucose-induced angiotensin II receptor-1 (AT-1), thus attenuating renal epithelial mesenchymal transition (EMT). Recently, we reported HPE inhibited dipeptidyl-peptidase-4 (DPP-4, the enzyme degrades type 1 glucagon-like peptide (GLP-1)), which mediated insulin resistance signals leading to EMT. Since free fatty acids can realistically bring about insulin resistance, using the palmitate-stimulated cell model in contrast with type 2 diabetic rats, in this study we examined if insulin resistance causes renal EMT, and the preventive effect of HPE. Our findings reveal that palmitate hindered 30% of glucose uptake. Treatment with 1 mg mL(-1) of HPE and the DPP-4 inhibitor linagliptin completely recovered insulin sensitivity and palmitate-induced signal cascades. HPE inhibited DPP-4 activity without altering the levels of DPP-4 and the GLP-1 receptor (GLP-1R). HPE decreased palmitate-induced phosphorylation of Ser307 of insulin receptor substrate-1 (pIRS-1 (S307)), AT-1 and vimentin, while increasing phosphorylation of phosphatidylinositol 3-kinase (pPI3K). IRS-1 knockdown revealed its essential role in mediating downstream AT-1 and EMT. In type 2 diabetic rats, it suggests that HPE concomitantly decreased the protein levels of DPP-4, AT-1, vimentin, and fibronectin, but reversed the in vivo compensation of GLP-1R. In conclusion, HPE improves insulin sensitivity by attenuating DPP-4 and the downstream signals, thus decreasing AT-1-mediated tubular-interstitial EMT. HPE could be an adjuvant to prevent diabetic nephropathy.

Macrophage diversity in renal injury and repair

NARCIS (Netherlands)

Ricardo, Sharon D.; van Goor, Harry; Eddy, Allison A.

Monocyte-derived macrophages can determine the outcome of the immune response and whether this response contributes to tissue repair or mediates tissue destruction. In addition to their important role in immune-mediated renal disease and host defense, macrophages play a fundamental role in tissue

Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

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Paweł Chmielarz

2017-11-01

Full Text Available The flavonoid-based macroinitiator was received for the first time by the transesterification reaction of quercetin with 2-bromoisobutyryl bromide. In accordance with the “grafting from” strategy, a naturally-occurring star-like polymer with a polar 3,3',4',5,6-pentahydroxyflavone core and hydrophobic poly(tert-butyl acrylate (PtBA side arms was synthesized via a simplified electrochemically mediated ATRP (seATRP, utilizing only 78 ppm by weight (wt of a catalytic CuII complex. To demonstrate the possibility of temporal control, seATRP was carried out utilizing a multiple-step potential electrolysis. The rate of the polymerizations was well-controlled by applying optimal potential values during preparative electrolysis to prevent the possibility of intermolecular coupling of the growing polymer arms. This appears to be the first report using on-demand seATRP for the synthesis of QC-(PtBA-Br5 pseudo-star polymers. The naturally-derived macromolecules showed narrow MWDs (Đ = 1.08–1.11. 1H NMR spectral results confirm the formation of quercetin-based polymers. These new flavonoid-based polymer materials may find applications as antifouling coatings and drug delivery systems.

Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits.

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Schiller, Alicia M; Pellegrino, Peter R; Zucker, Irving H

2016-01-15

Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits. Copyright © 2016 the American Physiological Society.

Renal and urinary levels of endothelial protein C receptor correlate with acute renal allograft rejection.

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Lionel Lattenist

Full Text Available The Endothelial Protein C Receptor (EPCR is expressed on leukocytes, on endothelium of large blood vessels and to a lesser extent on capillaries. Membrane bound EPCR plays an important role in the activation of protein C which has anticoagulant, anti-inflammatory and cytoprotective effects. After cleavage by a protease EPCR is also found as a soluble protein. Acute rejection of kidney allografts can be divided in T-cell-mediated rejection (TCMR and antibody-mediated (ABMR rejection. The latter is characterized by strong activation of coagulation. Currently no reliable non-invasive biomarkers are available to monitor rejection. Renal biopsies were available from 81 renal transplant patients (33 without rejection, 26 TCMR and 22 ABMR, we had access to mRNA material, matched plasma and urine samples for a portion of this cohort. Renal EPCR expression was assessed by RT-PCR and immunostaining. Plasma and urine sEPCR levels were measured by ELISA. ABMR patients showed higher levels of EPCR mRNA than TCMR patients. EPCR expression on glomeruli was significantly elevated in ABMR patients than in TCMR or control patients. In the peritubular capillaries EPCR expression was higher in ABMR patients than in control patients. EPCR expression was higher in tubules and arteries of rejection patients than in control patients. Plasma sEPCR levels did not differ. Urine sEPCR levels were more elevated in the ABMR group than in patients with TCMR or without rejection. ROC analysis demonstrated that urinary sEPCR is appropriate to discriminate between ABMR patients and TCMR or control patients. We conclude that urinary sEPCR could be a novel non-invasive biomarker of antibody mediated rejection in renal transplantation.

Cathepsin L is required for endothelial progenitor cell-induced neovascularization

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Urbich, Carmen; Heeschen, Christopher; Aicher, Alexandra; Sasaki, Ken-ichiro; Bruhl, Thomas; Hofmann, Wolf K.; Peters, Christoph; Reinheckel, Thomas; Pennacchio, Len A.; Abolmaali, Nasreddin D.; Chavakis, Emmanouil; Zeiher, Andreas M.; Dimmeler, Stefanie

2004-01-15

Infusion of endothelial progenitor cells (EPCs), but not of mature endothelial cells (ECs), promotes neovascularization after ischemia. We performed a gene expression profiling of EPCs and ECs to identify genes, which might be important for the neovascularization capacity of EPCs. Intriguingly, the protease cathepsin L (CathL) was highly expressed in EPCs as opposed to ECs and is essential for matrix degradation and invasion by EPCs in vitro. CathL deficient mice showed impaired functional recovery after hind limb ischemia supporting the concept for an important role of CathL in postnatal neovascularization. Infused CathL deficient progenitor cells failed to home to sites of ischemia and to augment neovascularization. In contrast, over expression of CathL in mature ECs significantly enhanced their invasive activity and induced their neovascularization capacity in vivo. Taken together, CathL plays a crucial role for the integration of circulating EPCs into the ischemic tissue and is required for neovascularization mediated by EPCs.

Defects in MAP1S-mediated autophagy turnover of fibronectin cause renal fibrosis.

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Xu, Guibin; Yue, Fei; Huang, Hai; He, Yongzhong; Li, Xun; Zhao, Haibo; Su, Zhengming; Jiang, Xianhan; Li, Wenjiao; Zou, Jing; Chen, Qi; Liu, Leyuan

2016-05-01

Excessive deposition of extracellular matrix proteins in renal tissues causes renal fibrosis and renal function failure. Mammalian cells primarily use the autophagy-lysosome system to degrade misfolded/aggregated proteins and dysfunctional organelles. MAP1S is an autophagy activator and promotes the biogenesis and degradation of autophagosomes. Previously, we reported that MAP1S suppresses hepatocellular carcinogenesis in a mouse model and predicts a better prognosis in patients suffering from clear cell renal cell carcinomas. Furthermore, we have characterized that MAP1S enhances the turnover of fibronectin, and mice overexpressing LC3 but with MAP1S deleted accumulate fibronectin and develop liver fibrosis because of the synergistic impact of LC3-induced over-synthesis of fibronectin and MAP1S depletion-caused impairment of fibronectin degradation. Here we show that a suppression of MAP1S in renal cells caused an impairment of autophagy clearance of fibronectin and an activation of pyroptosis. Depletion of MAP1S in mice leads to an accumulation of fibrosis-related proteins and the development of renal fibrosis in aged mice. The levels of MAP1S were dramatically reduced and levels of fibronectin were greatly elevated in renal fibrotic tissues from patients diagnosed as renal atrophy and renal failure. Therefore, MAP1S deficiency may cause the accumulation of fibronectin and the development of renal fibrosis.

Analysis of glycoprotein E-selectin ligANDs on human and mouse marrow cells enriched for hematopoietic stem/progenitor cells

KAUST Repository

Merzaban, Jasmeen; Burdick, Monica M.; Gadhoum, Samah; Dagia, Nilesh M.; Chu, Julia T.; Fuhlbrigge, Robert C.; Sackstein, Robert D.

2011-01-01

Although well recognized that expression of E-selectin on marrow microvessels mediates osteotropism of hematopoietic stem/progenitor cells (HSPCs), our knowledge regarding the cognate E-selectin ligand(s) on HSPCs is incomplete. Flow cytometry using

Amelioration of renal ischaemia-reperfusion injury by liposomal delivery of curcumin to renal tubular epithelial and antigen-presenting cells.

Science.gov (United States)

Rogers, N M; Stephenson, M D; Kitching, A R; Horowitz, J D; Coates, P T H

2012-05-01

Renal ischaemia-reperfusion (IR) injury is an inevitable consequence of renal transplantation, causing significant graft injury, increasing the risk of rejection and contributing to poor long-term graft outcome. Renal injury is mediated by cytokine and chemokine synthesis, inflammation and oxidative stress resulting from activation of the NF-κB pathway. We utilized liposomal incorporation of a potent inhibitor of the NF-κB pathway, curcumin, to target delivery to renal tubular epithelial and antigen-presenting cells. Liposomes containing curcumin were administered before bilateral renal ischaemia in C57/B6 mice, with subsequent reperfusion. Renal function was assessed from plasma levels of urea and creatinine, 4 and 24 h after reperfusion. Renal tissue was examined for NF-κB activity and oxidative stress (histology, immunostaining) and for apoptosis (TUNEL). Cytokines and chemokines were measured by RT-PCR and Western blotting. Liposomal curcumin significantly improved serum creatinine, reduced histological injury and cellular apoptosis and lowered Toll-like receptor-4, heat shock protein-70 and TNF-α mRNA expression. Liposomal curcumin also reduced neutrophil infiltration and diminished inflammatory chemokine expression. Curcumin liposomes reduced intracellular superoxide generation and increased superoxide dismutase levels, decreased inducible NOS mRNA expression and 3-nitrotyrosine staining consistent with limitations in nitrosative stress and inhibited renal tubular mRNA and protein expression of thioredoxin-interacting protein. These actions of curcumin were mediated by inhibition of NF-κB, MAPK and phospho-S6 ribosomal protein. Liposomal delivery of curcumin promoted effective, targeted delivery of this non-toxic compound that provided cytoprotection via anti-inflammatory and multiple antioxidant mechanisms following renal IR injury. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Renal albumin absorption in physiology and pathology.

Science.gov (United States)

Birn, H; Christensen, E I

2006-02-01

Albumin is the most abundant plasmaprotein serving multiple functions as a carrier of metabolites, hormones, vitamins, and drugs, as an acid/base buffer, as antioxidant and by supporting the oncotic pressure and volume of the blood. The presence of albumin in urine is considered to be the result of the balance between glomerular filtration and tubular reabsorption. Albuminuria has been accepted as an independent risk factor and a marker for renal as well as cardiovascular disease, and during the past decade, evidence has suggested that albumin itself may cause progression of renal disease. Thus, the reduction of proteinuria and, in particular, albuminuria has become a target in itself to prevent deterioration of renal function. Studies have shown albumin and its ligands to induce expression of inflammatory and fibrogenic mediators, and it has been hypothesized that increased filtration of albumin causes excessive tubular reabsorption, resulting in inflammation and fibrosis, resulting in the loss of renal function. In addition, it is known that tubular dysfunction in itself may cause albuminuria owing to decreased reabsorption of filtered albumin, and, recently, it has been suggested that significant amounts of albumin fragments are excreted in the urine as a result of tubular degradation. Thus, although both tubular and glomerular dysfunction influences renal handling of albumin, it appears that tubular reabsorption plays a central role in mediating the effects of albumin on renal function. The present paper will review the mechanisms for tubular albumin uptake and the possible implications for the development of renal disease.

Induction of multipotential hematopoietic progenitors from human pluripotent stem cells via re-specification of lineage-restricted precursors

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Doulatov, Sergei; Vo, Linda T.; Chou, Stephanie S.; Kim, Peter G.; Arora, Natasha; Li, Hu; Hadland, Brandon K.; Bernstein, Irwin D.; Collins, James J.; Zon, Leonard I.; Daley, George Q.

2013-01-01

Summary Human pluripotent stem cells (hPSCs) represent a promising source of patient-specific cells for disease modeling, drug screens, and cellular therapies. However, the inability to derive engraftable human hematopoietic stem and progenitor (HSPCs) has limited their characterization to in vitro assays. We report a strategy to re-specify lineage-restricted CD34+CD45+ myeloid precursors derived from hPSCs into multilineage progenitors that can be expanded in vitro and engraft in vivo. HOXA9, ERG, and RORA conferred self-renewal and multilineage potential in vitro and maintained primitive CD34+CD38− cells. Screening cells via transplantation revealed that two additional factors, SOX4 and MYB, were required for engraftment. Progenitors specified with all five factors gave rise to reproducible short-term engraftment with myeloid and erythroid lineages. Erythroid precursors underwent hemoglobin switching in vivo, silencing embryonic and activating adult globin expression. Our combinatorial screening approach establishes a strategy for obtaining transcription factor-mediated engraftment of blood progenitors from human pluripotent cells. PMID:24094326

Depression of Complement Regulatory Factors in Rat and Human Renal Grafts Is Associated with the Progress of Acute T-Cell Mediated Rejection.

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Kazuaki Yamanaka

Full Text Available The association of complement with the progression of acute T cell mediated rejection (ATCMR is not well understood. We investigated the production of complement components and the expression of complement regulatory proteins (Cregs in acute T-cell mediated rejection using rat and human renal allografts.We prepared rat allograft and syngeneic graft models of renal transplantation. The expression of Complement components and Cregs was assessed in the rat grafts using quantitative real-time PCR (qRT-PCR and immunofluorescent staining. We also administered anti-Crry and anti-CD59 antibodies to the rat allograft model. Further, we assessed the relationship between the expression of membrane cofactor protein (MCP by immunohistochemical staining in human renal grafts and their clinical course.qRT-PCR results showed that the expression of Cregs, CD59 and rodent-specific complement regulator complement receptor 1-related gene/protein-y (Crry, was diminished in the rat allograft model especially on day 5 after transplantation in comparison with the syngeneic model. In contrast, the expression of complement components and receptors: C3, C3a receptor, C5a receptor, Factor B, C9, C1q, was increased, but not the expression of C4 and C5, indicating a possible activation of the alternative pathway. When anti-Crry and anti-CD59 mAbs were administered to the allograft, the survival period for each group was shortened. In the human ATCMR cases, the group with higher MCP expression in the grafts showed improved serum creatinine levels after the ATCMR treatment as well as a better 5-year graft survival rate.We conclude that the expression of Cregs in allografts is connected with ATCMR. Our results suggest that controlling complement activation in renal grafts can be a new strategy for the treatment of ATCMR.

INTRAVENOUS IMMUNOGLOBULIN ADMINISTRATION FOR DESENSITIZATION BEFORE RENAL TRANSPLANTATION AND MANAGING ANTIBODY-MEDIATED REJECTION

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A. I. Sushkov

2011-01-01

Full Text Available Much attention has been placed recently in transplantation in highly HLA-sensitized patients. In attempts to remove these antibodies and enable successful renal transplantation, several approaches have been developed. Intravenous immunoglobulin (IVIG was found to be effective in the treatment of autoimmune and inflammatory disorders (e. g. Kawasaki disease, Guillain-Barre syndrome. Recently, a beneficial effect of IVIG on the reduc- tion of anti-HLA antibodies was described. The anti-inflammatory effect of IVIG provides hopeful opportunities in antibody-mediated rejection (AMR management. There are several protocols of IVIG administration for pre-transplant desensitization and AMR treatment: high-dose IVIG, low-dose IVIG + plasmapheresis, IVIG + plasmapheresis + rituximab. These advancements have enabled transplantation in patients previously considered untransplantable and in concert with new diagnostic techniques has resulted in new approaches to management of AMR. 

Progenitor Epithelium

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Marty-Santos, Leilani

2015-01-01

Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

Progenitor cells in pulmonary vascular remodeling

Science.gov (United States)

Yeager, Michael E.; Frid, Maria G.; Stenmark, Kurt R.

2011-01-01

Pulmonary hypertension is characterized by cellular and structural changes in the walls of pulmonary arteries. Intimal thickening and fibrosis, medial hypertrophy and fibroproliferative changes in the adventitia are commonly observed, as is the extension of smooth muscle into the previously non-muscularized vessels. A majority of these changes are associated with the enhanced presence of α-SM-actin+ cells and inflammatory cells. Atypical abundances of functionally distinct endothelial cells, particularly in the intima (plexiform lesions), and also in the perivascular regions, are also described. At present, neither the origin(s) of these cells nor the molecular mechanisms responsible for their accumulation, in any of the three compartments of the vessel wall, have been fully elucidated. The possibility that they arise from either resident vascular progenitors or bone marrow–derived progenitor cells is now well established. Resident vascular progenitor cells have been demonstrated to exist within the vessel wall, and in response to certain stimuli, to expand and express myofibroblastic, endothelial or even hematopoietic markers. Bone marrow–derived or circulating progenitor cells have also been shown to be recruited to sites of vascular injury and to assume both endothelial and SM-like phenotypes. Here, we review the data supporting the contributory role of vascular progenitors (including endothelial progenitor cells, smooth muscle progenitor cells, pericytes, and fibrocytes) in vascular remodeling. A more complete understanding of the processes by which progenitor cells modulate pulmonary vascular remodeling will undoubtedly herald a renaissance of therapies extending beyond the control of vascular tonicity and reduction of pulmonary artery pressure. PMID:22034593

Drug-interaction-induced hemodynamically mediated acute renal failure in postsurgical patient

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Arup K Misra

2014-01-01

Full Text Available Acute renal failure is a life threatening condition. Nonsteroidal antiinflammatory drugs (NSAIDs and cephalosporins are widely used postoperative drugs. NSAID-induced acute renal failure has been reported in the past. In this case, drug interaction and decompensated state of the patient precipitate the condition. NSAIDs inhibit prostaglandins synthesis and thus aggravate ischemia to the kidney that is already facing volume crisis due to surgery. Due to renal dysfunction, plasma ceftriaxone level increases due to decrease clearance and it also acts as nephrotoxic by unknown mechanism. On the other hand, ceftriaxone on its interaction with diclofenac for renal tubular clearance also increases the level of diclofenac and thus further aggravate the ischemia. It is a reversible condition with excluding diclofenac from the treatment regimen and giving adequate hydration to the patient. This highlights the importance of hydration and knowledge of drugs interactions in a postsurgical patient.

Phosphatidylinositol 3-kinase is essential for kit ligand-mediated survival, whereas interleukin-3 and flt3 ligand induce expression of antiapoptotic Bcl-2 family genes

DEFF Research Database (Denmark)

Karlsson, Richard; Engström, Maria; Jönsson, Maria

2003-01-01

Cytokines such as interleukin 3 (IL-3), kit ligand (KL), and flt3 ligand (FL) promote survival of hematopoietic stem cells and myeloid progenitor cells. In many cell types, members of the Bcl-2 gene family are major regulators of survival, but the mediating mechanisms are not fully understood....... Using two myeloid progenitor cell lines, FDCP-mix and FDC-P1, as well as primary mouse bone marrow progenitors, we demonstrate that KL-mediated survival is dependent on the activation of phosphatidylinositol-3 (PI-3) kinase. The inhibitor LY294002 was able to completely abolish survival mediated by KL...

Insulin-like growth factor-1 sustains stem cell mediated renal repair.

NARCIS (Netherlands)

Imberti, B.; Morigi, M.; Tomasoni, S.; Rota, C.; Corna, D.; Longaretti, L.; Rottoli, D.; Valsecchi, F.; Benigni, A.; Wang, J.; Abbate, M.; Zoja, C.; Remuzzi, G.

2007-01-01

In mice with cisplatin-induced acute kidney injury, administration of bone marrow-derived mesenchymal stem cells (MSC) restores renal tubular structure and improves renal function, but the underlying mechanism is unclear. Here, we examined the process of kidney cell repair in co-culture experiments

EXPERIMENTAL AND CLINICAL SIGNIFICANCE OF RENAL FUNCTIONAL RESERVE DETERMINATION

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Jernej Pajek

2002-07-01

Full Text Available Background. Renal functional reserve (RFR is defined as the temporary increase in glomerular filtration rate (GFR which follows the ingestion of proteins or infusion of aminoacids. This renal vasodilatatory response is probably mediated by several mechanisms, with nitric oxide being one of the most important mediators. In the last years significant progress in measuring renal functional reserve has been achieved on the basis of improvements in methods for accurate and timely appropriate GFR measurement. The method of GFR measurement using the sinistrin clearence calculation after bolus injection of sinistrin is increasingly employed.Conclusions. The article presents the latest results of experiments with RFR using this method and compares them with older reports. RFR is affected by several patophysiological processes: arterial hypertension, diabetes mellitus, deteriorating function of transplanted kidney. The results and impact of RFR determination in this conditions are described. Finally, potential for further research of RFR in atherosclerotic vascular disease is considered. Accurate determination of RFR is important for detection of early renal hemodynamic abnormalities, which can be influenced by therapeutic interventions and in this way the progression of renal functional deterioration could be prevented or at least slowed.

Transplanting oligodendrocyte progenitors into the adult CNS

International Nuclear Information System (INIS)

Franklin, R.J.M.; Blakemore, W.F.; Cambridge Univ.

1997-01-01

This review covers a number of aspects of the behaviour of oligodendrocyte progenitors following transplantation into the adult CNS. First, an account is given of the ability of transplanted oligodendrocyte progenitors, grown in tissue culture in the presence of PDGF and bFGF, to extensively remyelinate focal areas of persistent demyelination. Secondly, we describe how transplanted clonal cell lines of oligodendrocyte progenitors will differentiate in to astrocytes as will oligodendrocytes following transplantation into pathological environments in which both oligodendrocytes and astrocytes are absent, thereby manifesting the bipotentially demonstrable in vitro but not during development. Finally, a series of studies examining the migratory behaviour of transplanted oligodendrocyte progenitors (modelled using the oligodendrocyte progenitor cell line CG4) are described. (author)

Overexpression of CXCR4 on human CD34+ progenitors increases their proliferation, migration, and NOD/SCID repopulation.

Science.gov (United States)

Kahn, Joy; Byk, Tamara; Jansson-Sjostrand, Lottie; Petit, Isabelle; Shivtiel, Shoham; Nagler, Arnon; Hardan, Izhar; Deutsch, Varda; Gazit, Zulma; Gazit, Dan; Karlsson, Stefan; Lapidot, Tsvee

2004-04-15

A major limitation to clinical stem cell-mediated gene therapy protocols is the low levels of engraftment by transduced progenitors. We report that CXCR4 overexpression on human CD34+ progenitors using a lentiviral gene transfer technique helped navigate these cells to the murine bone marrow and spleen in response to stromal-derived factor 1 (SDF-1) signaling. Cells overexpressing CXCR4 exhibited significant increases in SDF-1-mediated chemotaxis and actin polymerization compared with control cells. A major advantage of CXCR4 overexpression was demonstrated by the ability of transduced CD34+ cells to respond to lower, physiologic levels of SDF-1 when compared to control cells, leading to improved SDF-1-induced migration and proliferation/survival, and finally resulting in significantly higher levels of in vivo repopulation of nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice including primitive CD34+/CD38(-/low) cells. Importantly, no cellular transformation was observed following transduction with the CXCR4 vector. Unexpectedly, we documented lack of receptor internalization in response to high levels of SDF-1, which can also contribute to increased migration and proliferation by the transduced CD34+ cells. Our results suggest CXCR4 overexpression for improved definitive human stem cell motility, retention, and multilineage repopulation, which could be beneficial for in vivo navigation and expansion of hematopoietic progenitors.

High Endogenous Accumulation of ω-3 Polyunsaturated Fatty Acids Protect against Ischemia-Reperfusion Renal Injury through AMPK-Mediated Autophagy in Fat-1 Mice.

Science.gov (United States)

Gwon, Do Hyeong; Hwang, Tae Woong; Ro, Ju-Ye; Kang, Yoon-Joong; Jeong, Jin Young; Kim, Do-Kyung; Lim, Kyu; Kim, Dong Woon; Choi, Dae Eun; Kim, Jwa-Jin

2017-09-30

Regulated autophagy is involved in the repair of renal ischemia-reperfusion injury (IRI). Fat-1 transgenic mice produce ω3-Polyunsaturated fatty acids (ω3-PUFAs) from ω6-Polyunsaturated fatty acids (ω6-PUFAs) without a dietary ω3-PUFAs supplement, leading to a high accumulation of omega-3 in various tissues. ω3-PUFAs show protective effects against various renal injuries and it has recently been reported that ω3-PUFAs regulate autophagy. We assessed whether ω3-PUFAs attenuated IR-induced acute kidney injury (AKI) and evaluated its associated mechanisms. C57Bl/6 background fat-1 mice and wild-type mice (wt) were divided into four groups: wt sham ( n = 10), fat-1 sham ( n = 10), wt IRI (reperfusion 35 min after clamping both the renal artery and vein; n = 15), and fat-1 IRI ( n = 15). Kidneys and blood were harvested 24 h after IRI and renal histological and molecular data were collected. The kidneys of fat-1 mice showed better renal cell survival, renal function, and pathological damage than those of wt mice after IRI. In addition, fat-1 mice showed less oxidative stress and autophagy impairment; greater amounts of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, Beclin-1, and Atg7; lower amounts of p62; and, higher levels of renal cathepsin D and ATP6E than wt kidneys. They also showed more adenosine monophosphate-activated protein kinase (AMPK) activation, which resulted in the inhibition of phosphorylation of the mammalian target of rapamycin (mTOR). Collectively, ω3-PUFAs in fat-1 mice contributed to AMPK mediated autophagy activation, leading to a renoprotective response.

[Plasma cell dyscrasias and renal damage].

Science.gov (United States)

Pasquali, Sonia; Iannuzzella, Francesco; Somenzi, Danio; Mattei, Silvia; Bovino, Achiropita; Corradini, Mattia

2012-01-01

Kidney damage caused by immunoglobulin free light chains in the setting of plasma cell dyscrasias is common and may involve all renal compartments, from the glomerulus to the tubulointerstitium, in a wide variety of histomorphological and clinical patterns. The knowledge of how free light chains can promote kidney injury is growing: they can cause functional changes, be processed and deposited, mediate inflammation, apoptosis and fibrosis, and obstruct nephrons. Each clone of the free light chain is unique and its primary structure and post-translation modification can determine the type of renal disease. Measurement of serum free light chain concentrations and calculation of the serum kappa/lambda ratio, together with renal biopsy, represent essential diagnostic tools. An early and correct diagnosis of renal lesions due to plasma cell dyscrasias will allow early initiation of disease-specific treatment strategies. The treatment of free light chain nephropathies is evolving and knowledge of the pathways that promote renal damage should lead to further therapeutic developments.

Sphingosine-1-phosphate and renal vasoconstriction

DEFF Research Database (Denmark)

Jensen, Boye L

2018-01-01

) and in conjunction with increased S1P release in pathophysiological situations like sepsis and ischemia-reperfusion incidents, this effect could be relevant in acute kidney injury with parallel decreases in renal blood flow and GFR. This article is protected by copyright. All rights reserved.......In the present issue of Acta Physiologica, Guan et al. in their article "Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles" (1) address the signaling events associated with sphingosine-1-phosphate (S1P)-mediated renal afferent vasoconstriction and show in......, technically demanding, blood-perfused juxtamedullary nephron preparation that S1P signaling relies predominantly on transmembrane calcium influx from the extracellular fluid through L-type calcium channels with contribution from oxidative stress metabolites(1) . So not only is new information on S1P signaling...

Focal Transplantation of Human iPSC-Derived Glial-Rich Neural Progenitors Improves Lifespan of ALS Mice

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Takayuki Kondo

2014-08-01

Full Text Available Transplantation of glial-rich neural progenitors has been demonstrated to attenuate motor neuron degeneration and disease progression in rodent models of mutant superoxide dismutase 1 (SOD1-mediated amyotrophic lateral sclerosis (ALS. However, translation of these results into a clinical setting requires a renewable human cell source. Here, we derived glial-rich neural progenitors from human iPSCs and transplanted them into the lumbar spinal cord of ALS mouse models. The transplanted cells differentiated into astrocytes, and the treated mouse group showed prolonged lifespan. Our data suggest a potential therapeutic mechanism via activation of AKT signal. The results demonstrated the efficacy of cell therapy for ALS by the use of human iPSCs as cell source.

Haematopoietic stem and progenitor cells from human pluripotent stem cells

Science.gov (United States)

Sugimura, Ryohichi; Jha, Deepak Kumar; Han, Areum; Soria-Valles, Clara; da Rocha, Edroaldo Lummertz; Lu, Yi-Fen; Goettel, Jeremy A.; Serrao, Erik; Rowe, R. Grant; Malleshaiah, Mohan; Wong, Irene; Sousa, Patricia; Zhu, Ted N.; Ditadi, Andrea; Keller, Gordon; Engelman, Alan N.; Snapper, Scott B.; Doulatov, Sergei; Daley, George Q.

2018-01-01

A variety of tissue lineages can be differentiated from pluripotent stem cells by mimicking embryonic development through stepwise exposure to morphogens, or by conversion of one differentiated cell type into another by enforced expression of master transcription factors. Here, to yield functional human haematopoietic stem cells, we perform morphogen-directed differentiation of human pluripotent stem cells into haemogenic endothelium followed by screening of 26 candidate haematopoietic stem-cell-specifying transcription factors for their capacity to promote multi-lineage haematopoietic engraftment in mouse hosts. We recover seven transcription factors (ERG, HOXA5, HOXA9, HOXA10, LCOR, RUNX1 and SPI1) that are sufficient to convert haemogenic endothelium into haematopoietic stem and progenitor cells that engraft myeloid, B and T cells in primary and secondary mouse recipients. Our combined approach of morphogen-driven differentiation and transcription-factor-mediated cell fate conversion produces haematopoietic stem and progenitor cells from pluripotent stem cells and holds promise for modelling haematopoietic disease in humanized mice and for therapeutic strategies in genetic blood disorders. PMID:28514439

Human neural progenitors express functional lysophospholipid receptors that regulate cell growth and morphology

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Callihan Phillip

2008-12-01

Full Text Available Abstract Background Lysophospholipids regulate the morphology and growth of neurons, neural cell lines, and neural progenitors. A stable human neural progenitor cell line is not currently available in which to study the role of lysophospholipids in human neural development. We recently established a stable, adherent human embryonic stem cell-derived neuroepithelial (hES-NEP cell line which recapitulates morphological and phenotypic features of neural progenitor cells isolated from fetal tissue. The goal of this study was to determine if hES-NEP cells express functional lysophospholipid receptors, and if activation of these receptors mediates cellular responses critical for neural development. Results Our results demonstrate that Lysophosphatidic Acid (LPA and Sphingosine-1-phosphate (S1P receptors are functionally expressed in hES-NEP cells and are coupled to multiple cellular signaling pathways. We have shown that transcript levels for S1P1 receptor increased significantly in the transition from embryonic stem cell to hES-NEP. hES-NEP cells express LPA and S1P receptors coupled to Gi/o G-proteins that inhibit adenylyl cyclase and to Gq-like phospholipase C activity. LPA and S1P also induce p44/42 ERK MAP kinase phosphorylation in these cells and stimulate cell proliferation via Gi/o coupled receptors in an Epidermal Growth Factor Receptor (EGFR- and ERK-dependent pathway. In contrast, LPA and S1P stimulate transient cell rounding and aggregation that is independent of EGFR and ERK, but dependent on the Rho effector p160 ROCK. Conclusion Thus, lysophospholipids regulate neural progenitor growth and morphology through distinct mechanisms. These findings establish human ES cell-derived NEP cells as a model system for studying the role of lysophospholipids in neural progenitors.

Defining an EPOR- regulated transcriptome for primary progenitors, including Tnfr-sf13c as a novel mediator of EPO- dependent erythroblast formation.

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Seema Singh

Full Text Available Certain concepts concerning EPO/EPOR action modes have been challenged by in vivo studies: Bcl-x levels are elevated in maturing erythroblasts, but not in their progenitors; truncated EPOR alleles that lack a major p85/PI3K recruitment site nonetheless promote polycythemia; and Erk1 disruption unexpectedly bolsters erythropoiesis. To discover novel EPO/EPOR action routes, global transcriptome analyses presently are applied to interrogate EPO/EPOR effects on primary bone marrow-derived CFUe-like progenitors. Overall, 160 EPO/EPOR target transcripts were significantly modulated 2-to 21.8-fold. A unique set of EPO-regulated survival factors included Lyl1, Gas5, Pim3, Pim1, Bim, Trib3 and Serpina 3g. EPO/EPOR-modulated cell cycle mediators included Cdc25a, Btg3, Cyclin-d2, p27-kip1, Cyclin-g2 and CyclinB1-IP-1. EPO regulation of signal transduction factors was also interestingly complex. For example, not only Socs3 plus Socs2 but also Spred2, Spred1 and Eaf1 were EPO-induced as negative-feedback components. Socs2, plus five additional targets, further proved to comprise new EPOR/Jak2/Stat5 response genes (which are important for erythropoiesis during anemia. Among receptors, an atypical TNF-receptor Tnfr-sf13c was up-modulated >5-fold by EPO. Functionally, Tnfr-sf13c ligation proved to both promote proerythroblast survival, and substantially enhance erythroblast formation. The EPOR therefore engages a sophisticated set of transcriptome response circuits, with Tnfr-sf13c deployed as one novel positive regulator of proerythroblast formation.

Immunological tolerance induced by galectin-1 in rat allogeneic renal transplantation.

Science.gov (United States)

Xu, Gaosi; Tu, Weiping; Xu, Chengyun

2010-06-01

The existed literatures indicated that galectin-1 has anti-inflammatory effects and plays a pivotal role in autoimmune diseases. Present study was to identify the roles of galectin-1 in acute animal renal allograft rejection. Rat acute rejection models were erected by allogeneic renal transplantation. Galectin-1 injection was performed in different concentrations in renal recipients post-transplantation. Recipient survivals, CD8+ T cell proliferation, production of IFN-gamma, levels of serum CD30, enzyme-linked immunoabsorbent spot assay (ELISPOT) and immunohistochemistry were observed or tested 7days after renal transplantation. Galectin-1 injection can prolong the recipient animal survival, reduce the serum levels of IFN-gamma, soluble CD30, percentage of CD8+ T cell subset, CD8+ T cell-mediated cytotoxicity, and IFN-gamma ELISPOT frequency for allograft recipients. The therapeutic effects of galectin-1 injection on recipient rats were dose-dependent. Galectin-1 plays an important role in CD8+ T cell-mediated renal rejection by inducing immunological tolerance. Copyright 2010 Elsevier B.V. All rights reserved.

MicroRNA-10b downregulation mediates acute rejection of renal allografts by derepressing BCL2L11

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Liu, Xiaoyou [Department of Organ Transplantation, Zhujiang Hospital, Guangzhou 510282 (China); Dong, Changgui [Institute of Molecular Ecology and Evolution, East China Normal University, Shanghai 200062 (China); Jiang, Zhengyao [Department of Organ Transplantation, Zhujiang Hospital, Guangzhou 510282 (China); Wu, William K.K. [Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, NT, Hong Kong (China); State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong (China); Chan, Matthew T.V. [Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, NT, Hong Kong (China); Zhang, Jie [Department of Organ Transplantation, Zhujiang Hospital, Guangzhou 510282 (China); Li, Haibin; Qin, Ke [Guangxi Key Laboratory for Transplantation Medicine Department of Organ Transplantation in Guangzhou Military Region, Institute of Transplant Medicine, 303 Hospital of People' s Liberation Army, Nanning, Guangxi 530021 (China); Sun, Xuyong, E-mail: sunxuyong0528@163.com [Guangxi Key Laboratory for Transplantation Medicine Department of Organ Transplantation in Guangzhou Military Region, Institute of Transplant Medicine, 303 Hospital of People' s Liberation Army, Nanning, Guangxi 530021 (China)

2015-04-10

Kidney transplantation is the major therapeutic option for end-stage kidney diseases. However, acute rejection could cause allograft loss in some of these patients. Emerging evidence supports that microRNA (miRNA) dysregulation is implicated in acute allograft rejection. In this study, we used next-generation sequencing to profile miRNA expression in normal and acutely rejected kidney allografts. Among 75 identified dysregulated miRNAs, miR-10b was the most significantly downregulated miRNAs in rejected allografts. Transfecting miR-10b inhibitor into human renal glomerular endothelial cells recapitulated key features of acute allograft rejection, including endothelial cell apoptosis, release of pro-inflammatory cytokines (interleukin-6, tumor necrosis factor α, interferon-γ, and chemokine (C–C motif) ligand 2) and chemotaxis of macrophages whereas transfection of miR-10b mimics had opposite effects. Downregulation of miR-10b directly derepressed the expression of BCL2L11 (an apoptosis inducer) as revealed by luciferase reporter assay. Taken together, miR-10b downregulation mediates many aspects of disease pathogenicity of acute kidney allograft rejection. Restoring miR-10b expression in glomerular endothelial cells could be a novel therapeutic approach to reduce acute renal allograft loss. - Highlights: • miR-10b was the most downregulated microRNAs in acutely rejected renal allografts. • miR-10b downregulation triggered glomerular endothelial cell apoptosis. • miR-10b downregulation induced release of pro-inflammatory cytokines. • miR-10b downregulation derepressed its pro-apoptotic target BCL2L11.

MicroRNA-10b downregulation mediates acute rejection of renal allografts by derepressing BCL2L11

International Nuclear Information System (INIS)

Liu, Xiaoyou; Dong, Changgui; Jiang, Zhengyao; Wu, William K.K.; Chan, Matthew T.V.; Zhang, Jie; Li, Haibin; Qin, Ke; Sun, Xuyong

2015-01-01

Kidney transplantation is the major therapeutic option for end-stage kidney diseases. However, acute rejection could cause allograft loss in some of these patients. Emerging evidence supports that microRNA (miRNA) dysregulation is implicated in acute allograft rejection. In this study, we used next-generation sequencing to profile miRNA expression in normal and acutely rejected kidney allografts. Among 75 identified dysregulated miRNAs, miR-10b was the most significantly downregulated miRNAs in rejected allografts. Transfecting miR-10b inhibitor into human renal glomerular endothelial cells recapitulated key features of acute allograft rejection, including endothelial cell apoptosis, release of pro-inflammatory cytokines (interleukin-6, tumor necrosis factor α, interferon-γ, and chemokine (C–C motif) ligand 2) and chemotaxis of macrophages whereas transfection of miR-10b mimics had opposite effects. Downregulation of miR-10b directly derepressed the expression of BCL2L11 (an apoptosis inducer) as revealed by luciferase reporter assay. Taken together, miR-10b downregulation mediates many aspects of disease pathogenicity of acute kidney allograft rejection. Restoring miR-10b expression in glomerular endothelial cells could be a novel therapeutic approach to reduce acute renal allograft loss. - Highlights: • miR-10b was the most downregulated microRNAs in acutely rejected renal allografts. • miR-10b downregulation triggered glomerular endothelial cell apoptosis. • miR-10b downregulation induced release of pro-inflammatory cytokines. • miR-10b downregulation derepressed its pro-apoptotic target BCL2L11

Renal denervation attenuates NADPH oxidase-mediated oxidative stress and hypertension in rats with hydronephrosis.

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Peleli, Maria; Al-Mashhadi, Ammar; Yang, Ting; Larsson, Erik; Wåhlin, Nils; Jensen, Boye L; G Persson, A Erik; Carlström, Mattias

2016-01-01

Hydronephrosis is associated with the development of salt-sensitive hypertension. Studies have suggested that increased sympathetic nerve activity and oxidative stress play important roles in hypertension and the modulation of salt sensitivity. The present study primarily aimed to examine the role of renal sympathetic nerve activity in the development of hypertension in rats with hydronephrosis. In addition, we aimed to investigate if NADPH oxidase (NOX) function could be affected by renal denervation. Partial unilateral ureteral obstruction (PUUO) was created in 3-wk-old rats to induce hydronephrosis. Sham surgery or renal denervation was performed at the same time. Blood pressure was measured during normal, high-, and low-salt diets. The renal excretion pattern, NOX activity, and expression as well as components of the renin-angiotensin-aldosterone system were characterized after treatment with the normal salt diet. On the normal salt diet, rats in the PUUO group had elevated blood pressure compared with control rats (115 ± 3 vs. 87 ± 1 mmHg, P < 0.05) and displayed increased urine production and lower urine osmolality. The blood pressure change in response to salt loading (salt sensitivity) was more pronounced in the PUUO group compared with the control group (15 ± 2 vs. 5 ± 1 mmHg, P < 0.05). Renal denervation in PUUO rats attenuated both hypertension (97 ± 3 mmHg) and salt sensitivity (5 ± 1 mmHg, P < 0.05) and normalized the renal excretion pattern, whereas the degree of renal fibrosis and inflammation was not changed. NOX activity and expression as well as renin and ANG II type 1A receptor expression were increased in the renal cortex from PUUO rats and normalized by denervation. Plasma Na(+) and K(+) levels were elevated in PUUO rats and normalized after renal denervation. Finally, denervation in PUUO rats was also associated with reduced NOX expression, superoxide production, and fibrosis in the heart. In conclusion, renal denervation attenuates

High Endogenous Accumulation of ω-3 Polyunsaturated Fatty Acids Protect against Ischemia-Reperfusion Renal Injury through AMPK-Mediated Autophagy in Fat-1 Mice

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Do Hyeong Gwon

2017-09-01

Full Text Available Regulated autophagy is involved in the repair of renal ischemia-reperfusion injury (IRI. Fat-1 transgenic mice produce ω3-Polyunsaturated fatty acids (ω3-PUFAs from ω6-Polyunsaturated fatty acids (ω6-PUFAs without a dietary ω3-PUFAs supplement, leading to a high accumulation of omega-3 in various tissues. ω3-PUFAs show protective effects against various renal injuries and it has recently been reported that ω3-PUFAs regulate autophagy. We assessed whether ω3-PUFAs attenuated IR-induced acute kidney injury (AKI and evaluated its associated mechanisms. C57Bl/6 background fat-1 mice and wild-type mice (wt were divided into four groups: wt sham (n = 10, fat-1 sham (n = 10, wt IRI (reperfusion 35 min after clamping both the renal artery and vein; n = 15, and fat-1 IRI (n = 15. Kidneys and blood were harvested 24 h after IRI and renal histological and molecular data were collected. The kidneys of fat-1 mice showed better renal cell survival, renal function, and pathological damage than those of wt mice after IRI. In addition, fat-1 mice showed less oxidative stress and autophagy impairment; greater amounts of microtubule-associated protein 1A/1B-light chain 3 (LC3-II, Beclin-1, and Atg7; lower amounts of p62; and, higher levels of renal cathepsin D and ATP6E than wt kidneys. They also showed more adenosine monophosphate-activated protein kinase (AMPK activation, which resulted in the inhibition of phosphorylation of the mammalian target of rapamycin (mTOR. Collectively, ω3-PUFAs in fat-1 mice contributed to AMPK mediated autophagy activation, leading to a renoprotective response.

Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance.

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Ando, Kazunori; Shibata, Eri; Hans, Stefan; Brand, Michael; Kawakami, Atsushi

2017-12-04

Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Organic cation transporter-mediated ergothioneine uptake in mouse neural progenitor cells suppresses proliferation and promotes differentiation into neurons.

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Takahiro Ishimoto

Full Text Available The aim of the present study is to clarify the functional expression and physiological role in neural progenitor cells (NPCs of carnitine/organic cation transporter OCTN1/SLC22A4, which accepts the naturally occurring food-derived antioxidant ergothioneine (ERGO as a substrate in vivo. Real-time PCR analysis revealed that mRNA expression of OCTN1 was much higher than that of other organic cation transporters in mouse cultured cortical NPCs. Immunocytochemical analysis showed colocalization of OCTN1 with the NPC marker nestin in cultured NPCs and mouse embryonic carcinoma P19 cells differentiated into neural progenitor-like cells (P19-NPCs. These cells exhibited time-dependent [(3H]ERGO uptake. These results demonstrate that OCTN1 is functionally expressed in murine NPCs. Cultured NPCs and P19-NPCs formed neurospheres from clusters of proliferating cells in a culture time-dependent manner. Exposure of cultured NPCs to ERGO or other antioxidants (edaravone and ascorbic acid led to a significant decrease in the area of neurospheres with concomitant elimination of intracellular reactive oxygen species. Transfection of P19-NPCs with small interfering RNA for OCTN1 markedly promoted formation of neurospheres with a concomitant decrease of [(3H]ERGO uptake. On the other hand, exposure of cultured NPCs to ERGO markedly increased the number of cells immunoreactive for the neuronal marker βIII-tubulin, but decreased the number immunoreactive for the astroglial marker glial fibrillary acidic protein (GFAP, with concomitant up-regulation of neuronal differentiation activator gene Math1. Interestingly, edaravone and ascorbic acid did not affect such differentiation of NPCs, in contrast to the case of proliferation. Knockdown of OCTN1 increased the number of cells immunoreactive for GFAP, but decreased the number immunoreactive for βIII-tubulin, with concomitant down-regulation of Math1 in P19-NPCs. Thus, OCTN1-mediated uptake of ERGO in NPCs inhibits

Possible promotion of neuronal differentiation in fetal rat brain neural progenitor cells after sustained exposure to static magnetism.

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Nakamichi, Noritaka; Ishioka, Yukichi; Hirai, Takao; Ozawa, Shusuke; Tachibana, Masaki; Nakamura, Nobuhiro; Takarada, Takeshi; Yoneda, Yukio

2009-08-15

We have previously shown significant potentiation of Ca(2+) influx mediated by N-methyl-D-aspartate receptors, along with decreased microtubules-associated protein-2 (MAP2) expression, in hippocampal neurons cultured under static magnetism without cell death. In this study, we investigated the effects of static magnetism on the functionality of neural progenitor cells endowed to proliferate for self-replication and differentiate into neuronal, astroglial, and oligodendroglial lineages. Neural progenitor cells were isolated from embryonic rat neocortex and hippocampus, followed by culture under static magnetism at 100 mT and subsequent determination of the number of cells immunoreactive for a marker protein of particular progeny lineages. Static magnetism not only significantly decreased proliferation of neural progenitor cells without affecting cell viability, but also promoted differentiation into cells immunoreactive for MAP2 with a concomitant decrease in that for an astroglial marker, irrespective of the presence of differentiation inducers. In neural progenitors cultured under static magnetism, a significant increase was seen in mRNA expression of several activator-type proneural genes, such as Mash1, Math1, and Math3, together with decreased mRNA expression of the repressor type Hes5. These results suggest that sustained static magnetism could suppress proliferation for self-renewal and facilitate differentiation into neurons through promoted expression of activator-type proneural genes by progenitor cells in fetal rat brain.

G9a and ZNF644 Physically Associate to Suppress Progenitor Gene Expression during Neurogenesis

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Jonathan B. Olsen

2016-09-01

Full Text Available Proliferating progenitor cells undergo changes in competence to give rise to post-mitotic progeny of specialized function. These cell-fate transitions typically involve dynamic regulation of gene expression by histone methyltransferase (HMT complexes. However, the composition, roles, and regulation of these assemblies in regulating cell-fate decisions in vivo are poorly understood. Using unbiased affinity purification and mass spectrometry, we identified the uncharacterized C2H2-like zinc finger protein ZNF644 as a G9a/GLP-interacting protein and co-regulator of histone methylation. In zebrafish, functional characterization of ZNF644 orthologs, znf644a and znf644b, revealed complementary roles in regulating G9a/H3K9me2-mediated gene silencing during neurogenesis. The non-overlapping requirements for znf644a and znf644b during retinal differentiation demarcate critical aspects of retinal differentiation programs regulated by differential G9a-ZNF644 associations, such as transitioning proliferating progenitor cells toward differentiation. Collectively, our data point to ZNF644 as a critical co-regulator of G9a/H3K9me2-mediated gene silencing during neuronal differentiation.

Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

International Nuclear Information System (INIS)

Seed, T.M.; Kaspar, L.V.

1990-01-01

Hematopoietic patterns have been assessed in chronic 60 Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author)

Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

Energy Technology Data Exchange (ETDEWEB)

Seed, T.M.; Kaspar, L.V. (Oak Ridge National Lab., TN (USA))

1990-01-01

Hematopoietic patterns have been assessed in chronic {sup 60}Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author).

Renal F4/80+ CD11c+ mononuclear phagocytes display phenotypic and functional characteristics of macrophages in health and in adriamycin nephropathy.

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Cao, Qi; Wang, Yiping; Wang, Xin Maggie; Lu, Junyu; Lee, Vincent W S; Ye, Qianling; Nguyen, Hanh; Zheng, Guoping; Zhao, Ye; Alexander, Stephen I; Harris, David C H

2015-02-01

Conventional markers of macrophages (Mфs) and dendritic cells (DCs) lack specificity and often overlap, leading to confusion and controversy regarding the precise function of these cells in kidney and other diseases. This study aimed to identify the phenotype and function of renal mononuclear phagocytes (rMPs) expressing key markers of both Mфs and DCs. F4/80(+)CD11c(+) cells accounted for 45% of total rMPs in normal kidneys and in those from mice with Adriamycin nephropathy (AN). Despite expression of the DC marker CD11c, these double-positive rMPs displayed the features of Mфs, including Mф-like morphology, high expression of CD68, CD204, and CD206, and high phagocytic ability but low antigen-presenting ability. F4/80(+)CD11c(+) cells were found in the cortex but not in the medulla of the kidney. In AN, F4/80(+)CD11c(+) cells displayed an M1 Mф phenotype with high expression of inflammatory mediators and costimulatory factors. Adoptive transfer of F4/80(+)CD11c(+) cells separated from diseased kidney aggravated renal injury in AN mice. Furthermore, adoptive transfer of common progenitors revealed that kidney F4/80(+)CD11c(+) cells were derived predominantly from monocytes, but not from pre-DCs. In conclusion, renal F4/80(+)CD11c(+) cells are a major subset of rMPs and display Mф-like phenotypic and functional characteristics in health and in AN. Copyright © 2015 by the American Society of Nephrology.

The Progenitor Dependence of Core-collapse Supernovae from Three-dimensional Simulations with Progenitor Models of 12–40 M ⊙

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Ott, Christian D.; Roberts, Luke F.; da Silva Schneider, André; Fedrow, Joseph M.; Haas, Roland; Schnetter, Erik

2018-03-01

We present a first study of the progenitor star dependence of the three-dimensional (3D) neutrino mechanism of core-collapse supernovae. We employ full 3D general-relativistic multi-group neutrino radiation-hydrodynamics and simulate the postbounce evolutions of progenitors with zero-age main sequence masses of 12, 15, 20, 27, and 40 M ⊙. All progenitors, with the exception of the 12 M ⊙ star, experience shock runaway by the end of their simulations. In most cases, a strongly asymmetric explosion will result. We find three qualitatively distinct evolutions that suggest a complex dependence of explosion dynamics on progenitor density structure, neutrino heating, and 3D flow. (1) Progenitors with massive cores, shallow density profiles, and high post-core-bounce accretion rates experience very strong neutrino heating and neutrino-driven turbulent convection, leading to early shock runaway. Accretion continues at a high rate, likely leading to black hole formation. (2) Intermediate progenitors experience neutrino-driven, turbulence-aided explosions triggered by the arrival of density discontinuities at the shock. These occur typically at the silicon/silicon–oxygen shell boundary. (3) Progenitors with small cores and density profiles without strong discontinuities experience shock recession and develop the 3D standing-accretion shock instability (SASI). Shock runaway ensues late, once declining accretion rate, SASI, and neutrino-driven convection create favorable conditions. These differences in explosion times and dynamics result in a non-monotonic relationship between progenitor and compact remnant mass.

Renal Ammonia Metabolism and Transport

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Weiner, I. David; Verlander, Jill W.

2015-01-01

Renal ammonia metabolism and transport mediates a central role in acid-base homeostasis. In contrast to most renal solutes, the majority of renal ammonia excretion derives from intrarenal production, not from glomerular filtration. Renal ammoniagenesis predominantly results from glutamine metabolism, which produces 2 NH4+ and 2 HCO3− for each glutamine metabolized. The proximal tubule is the primary site for ammoniagenesis, but there is evidence for ammoniagenesis by most renal epithelial cells. Ammonia produced in the kidney is either excreted into the urine or returned to the systemic circulation through the renal veins. Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3−-consuming process, resulting in no net benefit to acid-base homeostasis. Highly regulated ammonia transport by renal epithelial cells determines the proportion of ammonia excreted in the urine versus returned to the systemic circulation. The traditional paradigm of ammonia transport involving passive NH3 diffusion, protonation in the lumen and NH4+ trapping due to an inability to cross plasma membranes is being replaced by the recognition of limited plasma membrane NH3 permeability in combination with the presence of specific NH3-transporting and NH4+-transporting proteins in specific renal epithelial cells. Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K+, and by several hormones, such as mineralocorticoids, glucocorticoids and angiotensin II. This coordinated process of regulated ammonia production and transport is critical for the effective maintenance of acid-base homeostasis. PMID:23720285

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale.

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Böhm, Michael; Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome.

Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

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Mitch, William E.; Sands, Jeff M.

2015-01-01

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

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Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-12-20

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

Growth Factor-Activated Stem Cell Circuits and Stromal Signals Cooperatively Accelerate Non-Integrated iPSC Reprogramming of Human Myeloid Progenitors

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Park, Tea Soon; Huo, Jeffrey S.; Peters, Ann; Talbot, C. Conover; Verma, Karan; Zimmerlin, Ludovic; Kaplan, Ian M.; Zambidis, Elias T.

2012-01-01

Nonviral conversion of skin or blood cells into clinically useful human induced pluripotent stem cells (hiPSC) occurs in only rare fractions (∼0.001%–0.5%) of donor cells transfected with non-integrating reprogramming factors. Pluripotency induction of developmentally immature stem-progenitors is generally more efficient than differentiated somatic cell targets. However, the nature of augmented progenitor reprogramming remains obscure, and its potential has not been fully explored for improving the extremely slow pace of non-integrated reprogramming. Here, we report highly optimized four-factor reprogramming of lineage-committed cord blood (CB) myeloid progenitors with bulk efficiencies of ∼50% in purified episome-expressing cells. Lineage-committed CD33+CD45+CD34− myeloid cells and not primitive hematopoietic stem-progenitors were the main targets of a rapid and nearly complete non-integrated reprogramming. The efficient conversion of mature myeloid populations into NANOG+TRA-1-81+ hiPSC was mediated by synergies between hematopoietic growth factor (GF), stromal activation signals, and episomal Yamanaka factor expression. Using a modular bioinformatics approach, we demonstrated that efficient myeloid reprogramming correlated not to increased proliferation or endogenous Core factor expressions, but to poised expression of GF-activated transcriptional circuits that commonly regulate plasticity in both hematopoietic progenitors and embryonic stem cells (ESC). Factor-driven conversion of myeloid progenitors to a high-fidelity pluripotent state was further accelerated by soluble and contact-dependent stromal signals that included an implied and unexpected role for Toll receptor-NFκB signaling. These data provide a paradigm for understanding the augmented reprogramming capacity of somatic progenitors, and reveal that efficient induced pluripotency in other cell types may also require extrinsic activation of a molecular framework that commonly regulates self

Transcatheter Alcohol-Mediated Perivascular Renal Denervation With the Peregrine System: First-in-Human Experience.

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Fischell, Tim A; Ebner, Adrian; Gallo, Santiago; Ikeno, Fumiaki; Minarsch, Laura; Vega, Félix; Haratani, Nicole; Ghazarossian, Vartan E

2016-03-28

This study evaluated the first clinical use of a new endovascular approach to renal denervation, using chemical neurolysis, via periadventitial infusion of dehydrated alcohol (ethanol) to perform "perivascular" renal artery sympathetic denervation. Renal denervation remains a promising technology for the treatment of hypertension and other disorders. A novel 3-needle delivery device (Peregrine System Infusion Catheter, Ablative Solutions, Inc., Kalamazoo, Michigan) was introduced into the renal arteries of 18 subjects with refractory hypertension. Microdoses of alcohol were infused bilaterally via the 3 needles into to the adventitial space (0.30 ml/artery, 37 arteries). Renal artery angiography was performed at the time of the procedure and at 6 months (n = 16). The primary safety endpoints were complications associated with the catheter insertion and delivery of the neurolytic agent or any major vascular access complications. The secondary performance endpoint was a reduction in office-based systolic blood pressure at 6 months compared with baseline. Procedural success was achieved in 100% of subjects (N = 18) and arteries (N = 37). There were no study-related adverse clinical events at follow-up. One death of a subject was recorded but determined by the investigator and an independent medical monitor to be non-study related. There were no angiographic observations of renal artery stenosis, aneurysms, or other renal artery abnormalities at 6 months (32 renal arteries). Sixteen of the 18 subjects had a 6-month follow-up. The mean office systolic blood pressure decreased from 175 ± 17 mm Hg to 151 ± 26 mm Hg (-24 mm Hg). There was an average reduction of antihypertensive medications from 3.4 (baseline) to 2.0 per subject at 6 months. Chemical renal denervation using the infusion of very low doses of alcohol directly into the adventitial space appears to be feasible and safe. This approach may be a promising alternative approach to perform catheter-based renal

Unmasking of complements using proteinase-K in formalin fixed paraffin embedded renal biopsies

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R Nada

2016-01-01

Full Text Available Renal biopsy interpretation requires histopathology, direct immunofluorescence (DIF and electron microscopy. Formalin-fixed, paraffin-embedded tissue (FFPE sent for light microscopy can be used for DIF after antigen retrieval. However, complement staining has not been satisfactory. We standardized DIF using proteinase-K for antigen retrieval in FFPE renal biopsies. A pilot study was conducted on known cases of membranous glomerulonephritis (MGN, membranoproliferative type-1 (MPGN-1, immunoglobulin A nephropathy (IgAN, and anti-glomerular basement disease (anti-GBM. Immunofluorescence panel included fluorescein isothiocyanate (FITC conjugated IgG, IgA, IgM, complements (C3 and C1q, light chains (kappa, lambda and fibrinogen antibodies. After standardization of the technique, 75 renal biopsies and 43 autopsies cases were stained. Out of 43 autopsy cases, immune-complex mediated glomerulonephritis (GN was confirmed in 18 cases (Lupus nephritis-11, IgAN-6, MGN-1, complement-mediated dense deposit disease (DDD-1 and monoclonal diseases in 4 cases (amyloidosis-3, cast nephropathy-1. Immune-mediated injury was excluded in 17 cases (focal segmental glomerulosclerosis -3, crescentic GN-6 [pauci-immune-3, anti-GBM-3], thrombotic microangiopathy-5, atherosclerosis-3. Renal biopsies (n-75 where inadequate or no frozen sample was available; this technique classified 52 mesangiocapillary pattern as MPGN type-1-46, DDD-2 and (C3GN-4. Others were diagnosed as IgAN-3, lupus nephritis-2, MGN-4, diffuse proliferative glomerulonephritis (DPGN-1, Non-IC crescentic GN-1, monoclonal diseases-3. In nine cases, DIF on FFPE tissue could not help in making diagnosis. Proteinase-K enzymatic digestion of FFPE renal biopsies can unmask complements (both C3 and C1q in immune-complexes mediated and complement-mediated diseases. This method showed good results on autopsy tissues archived for as long as 15 years.

Impairment of circulating endothelial progenitors in Down syndrome

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Costa Valerio

2010-09-01

Full Text Available Abstract Background Pathological angiogenesis represents a critical issue in the progression of many diseases. Down syndrome is postulated to be a systemic anti-angiogenesis disease model, possibly due to increased expression of anti-angiogenic regulators on chromosome 21. The aim of our study was to elucidate some features of circulating endothelial progenitor cells in the context of this syndrome. Methods Circulating endothelial progenitors of Down syndrome affected individuals were isolated, in vitro cultured and analyzed by confocal and transmission electron microscopy. ELISA was performed to measure SDF-1α plasma levels in Down syndrome and euploid individuals. Moreover, qRT-PCR was used to quantify expression levels of CXCL12 gene and of its receptor in progenitor cells. The functional impairment of Down progenitors was evaluated through their susceptibility to hydroperoxide-induced oxidative stress with BODIPY assay and the major vulnerability to the infection with human pathogens. The differential expression of crucial genes in Down progenitor cells was evaluated by microarray analysis. Results We detected a marked decrease of progenitors' number in young Down individuals compared to euploid, cell size increase and some major detrimental morphological changes. Moreover, Down syndrome patients also exhibited decreased SDF-1α plasma levels and their progenitors had a reduced expression of SDF-1α encoding gene and of its membrane receptor. We further demonstrated that their progenitor cells are more susceptible to hydroperoxide-induced oxidative stress and infection with Bartonella henselae. Further, we observed that most of the differentially expressed genes belong to angiogenesis, immune response and inflammation pathways, and that infected progenitors with trisomy 21 have a more pronounced perturbation of immune response genes than infected euploid cells. Conclusions Our data provide evidences for a reduced number and altered

Carrier-mediated transport of peptides by the kidney

International Nuclear Information System (INIS)

Skopicki, H.A.

1988-01-01

Small peptide transport was characterized to determine if: (1) Multiple carriers are present in the luminal membrane of renal proximal tubular cells; (2) Carrier-mediated peptide transport is limited by size; and (3) Gentamicin inhibits carrier-mediated reabsorption of peptides. Uptake of glycyl-[ 3 H]proline (Gly-Pro) into renal brush border membrane vesicles demonstrated a dual affinity carrier system. Whether multiple carriers are present was further investigated by characterizing the uptake of [ 3 H]pyroglutamyl-histidine. To determine if carrier-mediated transport of peptides is limited by size of the molecule, uptake of the hydrolytically resistant tripeptide, [ 3 H]pryroglutamyl-histidyl-tryptophan (pGlu-His-Trp), and tetrapeptide, [ 3 H]pyroglutamyl-histidyl-tryptophyl-serine (pGlu-His-Trp-Ser) were assessed. These data indicate: multiple carriers exist on the luminal membrane of renal proximal tubular cells for the transport of dipeptides, and tripeptide pGlu-His-Trp and the tetrapeptide pGlu-His-Trp-Ser are not taken up by a carrier-mediated mechanism, suggesting that the carrier may be limited by the size of the substrate

Protective Effects of Green Tea Polyphenol Against Renal Injury Through ROS-Mediated JNK-MAPK Pathway in Lead Exposed Rats.

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Wang, Haidong; Li, Deyuan; Hu, Zhongze; Zhao, Siming; Zheng, Zhejun; Li, Wei

2016-06-30

To investigate the potential therapeutic effects of polyphenols in treating Pb induced renal dysfunction and intoxication and to explore the detailed underlying mechanisms. Wistar rats were divided into four groups: control groups (CT), Pb exposure groups (Pb), Pb plus Polyphenols groups (Pb+PP) and Polyphenols groups (PP). Animals were kept for 60 days and sacrificed for tests of urea, serum blood urea nitrogen (BUN) and creatinine. Histological evaluations were then performed. In vitro studies were performed using primary kidney mesangial cells to reveal detailed mechanisms. Cell counting kit-8 (CCK-8) was used to evaluate cell viability. Pb induced cell apoptosis was measured by flow cytometry. Reactive oxygen species (ROS) generation and scavenging were tested by DCFH-DA. Expression level of tumor necrosis factor-α (TNF-α), interleukin-1-β (IL-1-β) and IL-6 were assayed by ELISA. Western blot and qPCR were used to measure the expression of ERK1/2, JNK1/2 and p38. Polyphenols have obvious protective effects on Pb induced renal dysfunction and intoxication both in vivo and in vitro. Polyphenols reduced Pb concentration and accumulation in kidney. Polyphenols also protected kidney mesangial cells from Pb induced apoptosis. Polyphenols scavenged Pb induced ROS generation and suppressed ROS-mediated ERK/JNK/p38 pathway. Downstream pro-inflammatory cytokines were inhibited in consistency. Polyphenol is protective in Pb induced renal intoxication and inflammatory responses. The underlying mechanisms lie on the antioxidant activity and ROS scavenging activity of polyphenols.

Cataclysmic Variables as Supernova Ia Progenitors

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Stella Kafka

2012-06-01

Full Text Available Although the identification of the progenitors of type Ia supernovae (SNeIa remains controversial, it is generally accepted that they originate from binary star systems in which at least one component is a carbon-oxygen white dwarf (WD; those systems are grouped under the wide umbrella of cataclysmic variables. Current theories for SNeIa progenitors hold that, either via Roche lobe overflow of the companion or via a wind, the WD accumulates hydrogen or helium rich material which is then burned to C and O onto the WD’s surface. However, the specifics of this scenario are far from being understood or defined, allowing for a wealth of theories fighting for attention and a dearth of observations to support them. I discuss the latest attempts to identify and study those controversial SNeIa progenitors. I also introduce the most promising progenitor in hand and I present observational diagnostics that can reveal more members of the category.

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale

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Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome. PMID:28154583

Renal sodium retention in cirrhotic rats depends on glucocorticoid-mediated activation of mineralocorticoid receptor due to decreased renal 11beta-HSD-2 activity

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Thiesson, Helle; Jensen, Boye L; Bistrup, Claus

2007-01-01

Downregulation of the renal glucocorticoid-metabolizing enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD-2) during liver cirrhosis may allow activation of the mineralocorticoid receptor (MR) by glucocorticoids and contribute to sodium retention. We tested this hypothesis in male Wistar...... rats with decompensated liver cirrhosis and ascites 7 wk after bile duct ligation (BDL). Renal 11beta-HSD-2 mRNA, protein, and activity were significantly decreased in decompensated rats. The urinary Na(+)/K(+) ratio was reduced by 40%. Renal epithelial sodium channel (ENaC) mRNA and immunostaining...... were only slightly affected. Complete metabolic studies, including fecal excretion, showed that the BDL rats had avid renal sodium retention. Treatment of the BDL rats with dexamethasone suppressed endogenous glucocorticoid production, normalized total sodium balance and renal sodium excretion...

Hypoxia inducible factor-2α regulates the development of retinal astrocytic network by maintaining adequate supply of astrocyte progenitors.

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Li-Juan Duan

Full Text Available Here we investigate the role of hypoxia inducible factor (HIF-2α in coordinating the development of retinal astrocytic and vascular networks. Three Cre mouse lines were used to disrupt floxed Hif-2α, including Rosa26(CreERT2, Tie2(Cre, and GFAP(Cre. Global Hif-2α disruption by Rosa26(CreERT2 led to reduced astrocytic and vascular development in neonatal retinas, whereas endothelial disruption by Tie2(Cre had no apparent effects. Hif-2α deletion in astrocyte progenitors by GFAP(Cre significantly interfered with the development of astrocytic networks, which failed to reach the retinal periphery and were incapable of supporting vascular development. Perplexingly, the abundance of strongly GFAP(+ mature astrocytes transiently increased at P0 before they began to lag behind the normal controls by P3. Pax2(+ and PDGFRα(+ astrocytic progenitors and immature astrocytes were dramatically diminished at all stages examined. Despite decreased number of astrocyte progenitors, their proliferation index or apoptosis was not altered. The above data can be reconciled by proposing that HIF-2α is required for maintaining the supply of astrocyte progenitors by slowing down their differentiation into non-proliferative mature astrocytes. HIF-2α deficiency in astrocyte progenitors may accelerate their differentiation into astrocytes, a change which greatly interferes with the replenishment of astrocyte progenitors due to insufficient time for proliferation. Rapidly declining progenitor supply may lead to premature cessation of astrocyte development. Given that HIF-2α protein undergoes oxygen dependent degradation, an interesting possibility is that retinal blood vessels may regulate astrocyte differentiation through their oxygen delivery function. While our findings support the consensus that retinal astrocytic template guides vascular development, they also raise the possibility that astrocytic and vascular networks may mutually regulate each other

PSGL-1–mediated activation of EphB4 increases the proangiogenic potential of endothelial progenitor cells

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Foubert, Philippe; Silvestre, Jean-Sébastien; Souttou, Boussad; Barateau, Véronique; Martin, Coralie; Ebrahimian, Téni G.; Leré-Déan, Carole; Contreres, Jean Olivier; Sulpice, Eric; Levy, Bernard I.; Plouët, Jean; Tobelem, Gérard; Le Ricousse-Roussanne, Sophie

2007-01-01

Endothelial progenitor cell (EPC) transplantation has beneficial effects for therapeutic neovascularization; however, only a small proportion of injected cells home to the lesion and incorporate into the neocapillaries. Consequently, this type of cell therapy requires substantial improvement to be of clinical value. Erythropoietin-producing human hepatocellular carcinoma (Eph) receptors and their ephrin ligands are key regulators of vascular development. We postulated that activation of the EphB4/ephrin-B2 system may enhance EPC proangiogenic potential. In this report, we demonstrate in a nude mouse model of hind limb ischemia that EphB4 activation with an ephrin-B2–Fc chimeric protein increases the angiogenic potential of human EPCs. This effect was abolished by EphB4 siRNA, confirming that it is mediated by EphB4. EphB4 activation enhanced P selectin glycoprotein ligand-1 (PSGL-1) expression and EPC adhesion. Inhibition of PSGL-1 by siRNA reversed the proangiogenic and adhesive effects of EphB4 activation. Moreover, neutralizing antibodies to E selectin and P selectin blocked ephrin-B2–Fc–stimulated EPC adhesion properties. Thus, activation of EphB4 enhances EPC proangiogenic capacity through induction of PSGL-1 expression and adhesion to E selectin and P selectin. Therefore, activation of EphB4 is an innovative and potentially valuable therapeutic strategy for improving the recruitment of EPCs to sites of neovascularization and thereby the efficiency of cell-based proangiogenic therapy. PMID:17510705

Renal Tubule Repair: Is Wnt/β-Catenin a Friend or Foe?

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Gewin, Leslie S

2018-01-24

Wnt/β-catenin signaling is extremely important for proper kidney development. This pathway is also upregulated in injured renal tubular epithelia, both in acute kidney injury and chronic kidney disease. The renal tubular epithelium is an important target of kidney injury, and its response (repair versus persistent injury) is critical for determining whether tubulointerstitial fibrosis, the hallmark of chronic kidney disease, develops. This review discusses how Wnt/β-catenin signaling in the injured tubular epithelia promotes either repair or fibrosis after kidney injury. There is data suggesting that epithelial Wnt/β-catenin signaling is beneficial in acute kidney injury and important in tubular progenitors responsible for epithelial repair. The role of Wnt/β-catenin signaling in chronically injured epithelia is less clear. There is convincing data that Wnt/β-catenin signaling in interstitial fibroblasts and pericytes contributes to the extracellular matrix accumulation that defines fibrosis. However, some recent studies question whether Wnt/β-catenin signaling in chronically injured epithelia actually promotes fibrosis or repair.

Targeting of the BLT2 in chronic myeloid leukemia inhibits leukemia stem/progenitor cell function

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Xiao, Meifang; Ai, Hongmei; Li, Tao [Department of Laboratory Medicine, JingZhou Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Jingzhou (China); Rajoria, Pasupati; Shahu, Prakash [Department of Clinical Medicine, Medical School of Yangtze University, Jingzhou (China); Li, Xiansong, E-mail: lixiansongjz@hotmail.com [Department of Neurosurgery, JingZhou Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Jingzhou (China)

2016-04-15

Imatinib, a tyrosine kinase inhibitor (TKI) has significantly improved clinical outcome for chronic myeloid leukemia (CML) patients. However, patients develop resistance when the disease progresses to the blast phase (BP) and the mechanisms are not well understood. Here we show that BCR-ABL activates BLT2 in hematopoietic stem/progenitor cells to promote leukemogenesis and this involves the p53 signaling pathway. Compared to normal bone marrow (NBM), the mRNA and protein levels of BLT2 are significantly increased in BP-CML CD34{sup +} stem/progenitor cells. This is correlated with increasing BCR-ABL expression. In contrast, knockdown of BCR-ABL or inhibition of its tyrosine kinase activity decreases Blt2 protein level. BLT2 inhibition induces apoptosis, inhibits proliferation, colony formation and self-renewal capacity of CD34{sup +} cells from TKI-resistant BP-CML patients. Importantly, the inhibitory effects of BCR-ABL TKI on CML stem/progenitor cells are further enhanced upon combination with BLT2 inhibition. We further show that BLT2 activation selectively suppresses p53 but not Wnt or BMP-mediated luciferase activity and transcription. Our results demonstrate that BLT2 is a novel pathway activated by BCR-ABL and critically involved in the resistance of BP-CML CD34{sup +} stem/progenitors to TKIs treatment. Our findings suggest that BLT2 and p53 can serve as therapeutic targets for CML treatment. - Highlights: • BCR-ABL regulates BLT2 expression to promote leukemogenesis. • BLT2 is essential to maintain CML cell function. • Activation of BLT2 suppresses p53 signaling pathway in CML cells. • Inhibition of BLT2 and BCR-ABL synergize in eliminating CML CD34{sup +} stem/progenitors.

Reduced Erg Dosage Impairs Survival of Hematopoietic Stem and Progenitor Cells.

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Xie, Ying; Koch, Mia Lee; Zhang, Xin; Hamblen, Melanie J; Godinho, Frank J; Fujiwara, Yuko; Xie, Huafeng; Klusmann, Jan-Henning; Orkin, Stuart H; Li, Zhe

2017-07-01

ERG, an ETS family transcription factor frequently overexpressed in human leukemia, has been implicated as a key regulator of hematopoietic stem cells. However, how ERG controls normal hematopoiesis, particularly at the stem and progenitor cell level, and how it contributes to leukemogenesis remain incompletely understood. Using homologous recombination, we generated an Erg knockdown allele (Erg kd ) in which Erg expression can be conditionally restored by Cre recombinase. Erg kd/kd animals die at E10.5-E11.5 due to defects in endothelial and hematopoietic cells, but can be completely rescued by Tie2-Cre-mediated restoration of Erg in these cells. In Erg kd/+ mice, ∼40% reduction in Erg dosage perturbs both fetal liver and bone marrow hematopoiesis by reducing the numbers of Lin - Sca-1 + c-Kit + (LSK) hematopoietic stem and progenitor cells (HSPCs) and megakaryocytic progenitors. By genetic mosaic analysis, we find that Erg-restored HSPCs outcompete Erg kd/+ HSPCs for contribution to adult hematopoiesis in vivo. This defect is in part due to increased apoptosis of HSPCs with reduced Erg dosage, a phenotype that becomes more drastic during 5-FU-induced stress hematopoiesis. Expression analysis reveals that reduced Erg expression leads to changes in expression of a subset of ERG target genes involved in regulating survival of HSPCs, including increased expression of a pro-apoptotic regulator Bcl2l11 (Bim) and reduced expression of Jun. Collectively, our data demonstrate that ERG controls survival of HSPCs, a property that may be used by leukemic cells. Stem Cells 2017;35:1773-1785. © 2017 AlphaMed Press.

Activation of GLP-1 receptors on vascular smooth muscle cells reduces the autoregulatory response in afferent arterioles and increases renal blood flow

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Jensen, Elisa Pouline; Poulsen, Steen Seier; Kissow, Hannelouise

2015-01-01

was to localize renal GLP-1 receptors and describe GLP-1 mediated effects on the renal vasculature. We hypothesized that renal GLP-1 receptors are located in the renal microcirculation and activation of these affects renal autoregulation and increases renal blood flow. In vivo autoradiography using 125I-GLP-1......, 125I-exendin-4 (GLP-1 analog) and 125I-exendin 9-39 (GLP-1 receptor antagonist) was performed in rodents to localize specific GLP-1 receptor binding. GLP-1 mediated effects on blood pressure (BP), renal blood flow (RBF), heart rate (HR), renin secretion, urinary flow rate and Na+ and K+ excretion were...... conclude that GLP-1 receptors are located in the renal vasculature including afferent arterioles. Activation of these receptors reduces the autoregulatory response of afferent arterioles to acute pressure increases and increases renal blood flow in normotensive rats....

Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice.

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Choi, Yu-Jin; Choi, Yun-Sik

2016-02-01

Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spatial working memory was examined with a Y maze, and proliferation of hippocampal progenitor cells were examined by 5-bromo-2'-deoxyuridine administration and immunohistochemical detection. When spatial working memory on a Y maze was examined in the 9(th) week, there was no significant difference in the spontaneous alternation score on the Y maze between the two groups. In addition, there was no significant difference in hippocampal progenitor cell proliferation. However, immunoreactivity to glial fibrillary acidic protein was increased in exposed animals. Next, to test the effect of recovery following chronic radiation exposure, the remaining female mice were further exposed to electromagnetic radiation for 2 more weeks (total 11 weeks), and spontaneous alternation was tested 4 weeks later. In this experiment, although there was no significant difference in the spontaneous alternation scores, the number of arm entry was significantly increased. These data indicate that although chronic electromagnetic radiation does not affect spatial working memory and hippocampal progenitor cell proliferation it can mediate astrocyte activation in the hippocampus and delayed hyperactivity-like behavior.

Requirement for Pdx1 in specification of latent endocrine progenitors in zebrafish

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Ellertsdottir Elin

2011-10-01

Full Text Available Abstract Background Insulin-producing beta cells emerge during pancreas development in two sequential waves. Recently described later-forming beta cells in zebrafish show high similarity to second wave mammalian beta cells in developmental capacity. Loss-of-function studies in mouse and zebrafish demonstrated that the homeobox transcription factors Pdx1 and Hb9 are both critical for pancreas and beta cell development and discrete stage-specific requirements for these genes have been uncovered. Previously, exocrine and endocrine cell recovery was shown to follow loss of pdx1 in zebrafish, but the progenitor cells and molecular mechanisms responsible have not been clearly defined. In addition, interactions of pdx1 and hb9 in beta cell formation have not been addressed. Results To learn more about endocrine progenitor specification, we examined beta cell formation following morpholino-mediated depletion of pdx1 and hb9. We find that after early beta cell reduction, recovery occurs following loss of either pdx1 or hb9 function. Unexpectedly, simultaneous knockdown of both hb9 and pdx1 leads to virtually complete and persistent beta cell deficiency. We used a NeuroD:EGFP transgenic line to examine endocrine cell behavior in vivo and developed a novel live-imaging technique to document emergence and migration of late-forming endocrine precursors in real time. Our data show that Notch-responsive progenitors for late-arising endocrine cells are predominantly post mitotic and depend on pdx1. By contrast, early-arising endocrine cells are specified and differentiate independent of pdx1. Conclusions The nearly complete beta cell deficiency after combined loss of hb9 and pdx1 suggests functional cooperation, which we clarify as distinct roles in early and late endocrine cell formation. A novel imaging approach permitted visualization of the emergence of late endocrine cells within developing embryos for the first time. We demonstrate a pdx1-dependent

PAX7 Targets, CD54, Integrin α9β1, and SDC2, Allow Isolation of Human ESC/iPSC-Derived Myogenic Progenitors

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Alessandro Magli

2017-06-01

Full Text Available Pluripotent stem (PS-cell-derived cell types hold promise for treating degenerative diseases. However, PS cell differentiation is intrinsically heterogeneous; therefore, clinical translation requires the development of practical methods for isolating progenitors from unwanted and potentially teratogenic cells. Muscle-regenerating progenitors can be derived through transient PAX7 expression. To better understand the biology, and to discover potential markers for these cells, here we investigate PAX7 genomic targets and transcriptional changes in human cells undergoing PAX7-mediated myogenic commitment. We identify CD54, integrin α9β1, and Syndecan2 (SDC2 as surface markers on PAX7-induced myogenic progenitors. We show that these markers allow for the isolation of myogenic progenitors using both fluorescent- and CGMP-compatible magnetic-based sorting technologies and that CD54+α9β1+SDC2+ cells contribute to long-term muscle regeneration in vivo. These findings represent a critical step toward enabling the translation of PS-cell-based therapies for muscle diseases.

A new perspective on the pathogenesis of chronic renal disease in captive cheetahs (Acinonyx jubatus).

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Mitchell, Emily P; Prozesky, Leon; Lawrence, John

2018-01-01

The sustainability of captive cheetah populations is limited by high mortality due to chronic renal disease. This necropsy study, conducted on 243 captive cheetahs from one institution, investigated the relationships between focal palatine erosions, gastritis, enterocolitis, glomerulosclerosis, chronic renal infarcts, renal cortical and medullary fibrosis, and renal medullary amyloidosis at death. Associations between the individual renal lesions and death due to chronic renal disease and comparisons of lesion prevalence between captive bred and wild born and between normal and king coated cheetahs were also assessed. All lesions were significantly positively correlated with age at death. Renal medullary fibrosis was the only lesion associated with the likelihood of death being due to chronic renal disease, and cheetahs with this lesion were younger, on average, than cheetahs with other renal lesions. Alimentary tract lesions were not associated with amyloidosis. All lesions, except for palatine erosions, were more common in wild born than in captive bred cheetahs; the former were older at death than the latter. Having a king coat had no clear effect on disease prevalence. These results suggest that age and renal medullary fibrosis are the primary factors influencing the pathogenesis of chronic renal disease in captive cheetahs. Apart from amyloidosis, these findings are analogous to those described in chronic renal disease in domestic cats, which is postulated to result primarily from repetitive hypoxic injury of renal tubules, mediated by age and stress. Cheetahs may be particularly susceptible to acute renal tubular injury due to their propensity for stress and their extended life span in captivity, as well as their adaptation for fecundity (rather than longevity) and adrenaline-mediated high speed prey chases. The presence of chronic renal disease in subadult cheetahs suggests that prevention, identification and mitigation of stress are critical to the

Changes in forearm muscle temperature alter renal vascular responses to isometric handgrip.

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Kuipers, Nathan T; Sauder, Charity L; Kearney, Matthew L; Ray, Chester A

2007-12-01

The purpose of the present study was to examine the effect of heating and cooling the forearm muscles on renal vascular responses to ischemic isometric handgrip (IHG). It was hypothesized that heating and cooling the forearm would augment and attenuate, respectively, renal vascular responses to IHG. Renal vascular responses to IHG were studied during forearm heating at 39 degrees C (n = 15, 26 +/- 1 yr) and cooling at 26 degrees C (n = 12, 26 +/- 1 yr). For a control trial, subjects performed the experimental protocol while the forearm was normothermic (approximately 34 degrees C). Muscle temperature (measured by intramuscular probe) was controlled by changing the temperature of water cycling through a water-perfused sleeve. The experimental protocol was as follows: 3 min at baseline, 1 min of ischemia, ischemic IHG to fatigue, and 2 min of postexercise muscle ischemia. At rest, renal artery blood velocity (RBV; Doppler ultrasound) and renal vascular conductance (RVC = RBV/mean arterial blood pressure) were not different between normothermia and the two thermal conditions. During ischemic IHG, there were greater decreases in RBV and RVC in the heating trial. However, RBV and RVC were similar during postexercise muscle ischemia during heating and normothermia. RVC decreased less during cooling than in normothermia while the subjects performed the ischemic IHG protocol. During postexercise muscle ischemia, RVC was greater during cooling than in normothermia. These results indicate that heating augments mechanoreceptor-mediated renal vasoconstriction whereas cooling blunts metaboreceptor-mediated renal vasoconstriction.

In Vivo Clonal Analysis Reveals Lineage-Restricted Progenitor Characteristics in Mammalian Kidney Development, Maintenance, and Regeneration

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Yuval Rinkevich

2014-05-01

Full Text Available 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, maintenance, and regeneration. We show that the adult mammalian kidney undergoes continuous tubulogenesis via expansions of fate-restricted clones. Kidneys recovering from damage undergo tubulogenesis through expansions of clones with segment-specific borders, and renal spheres developing in vitro from individual cells maintain distinct, segment-specific fates. Analysis of mice derived by transfer of color-marked embryonic stem cells (ESCs into uncolored blastocysts demonstrates that nephrons are polyclonal, developing from expansions of singly fated clones. Finally, we show that adult renal clones are derived from Wnt-responsive precursors, and their tracing in vivo generates tubules that are segment specific. Collectively, these analyses demonstrate that fate-restricted precursors functioning as unipotent progenitors continuously maintain and self-preserve the mouse kidney throughout life.

Closure of multiple types of K+ channels is necessar to induce changes in renal vascular resistance in vivo in rats

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Sørensen, Charlotte Mehlin; Giese, Isaiah; Braunstein, Thomas Hartig

2011-01-01

Inhibition of K(+) channels might mediate renal vasoconstriction. As inhibition of a single type of K(+) channel caused minor or no renal vasoconstriction in vivo in rats, we hypothesized that several classes of K(+) channels must be blocked to elicit renal vasoconstriction. We measured renal blo...

PROGENITOR-EXPLOSION CONNECTION AND REMNANT BIRTH MASSES FOR NEUTRINO-DRIVEN SUPERNOVAE OF IRON-CORE PROGENITORS

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Ugliano, Marcella; Janka, Hans-Thomas; Marek, Andreas [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Arcones, Almudena [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstr. 2, D-64289 Darmstadt (Germany)

2012-09-20

We perform hydrodynamic supernova (SN) simulations in spherical symmetry for over 100 single stars of solar metallicity to explore the progenitor-explosion and progenitor-remnant connections established by the neutrino-driven mechanism. We use an approximative treatment of neutrino transport and replace the high-density interior of the neutron star (NS) by an inner boundary condition based on an analytic proto-NS core-cooling model, whose free parameters are chosen such that explosion energy, nickel production, and energy release by the compact remnant of progenitors around 20 M{sub Sun} are compatible with SN 1987A. Thus, we are able to simulate the accretion phase, initiation of the explosion, subsequent neutrino-driven wind phase for 15-20 s, and the further evolution of the blast wave for hours to days until fallback is completed. Our results challenge long-standing paradigms. We find that remnant mass, launch time, and properties of the explosion depend strongly on the stellar structure and exhibit large variability even in narrow intervals of the progenitors' zero-age main-sequence mass. While all progenitors with masses below {approx}15 M{sub Sun} yield NSs, black hole (BH) as well as NS formation is possible for more massive stars, where partial loss of the hydrogen envelope leads to weak reverse shocks and weak fallback. Our NS baryonic masses of {approx}1.2-2.0 M{sub Sun} and BH masses >6 M{sub Sun} are compatible with a possible lack of low-mass BHs in the empirical distribution. Neutrino heating accounts for SN energies between some 10{sup 50} erg and {approx}2 Multiplication-Sign 10{sup 51} erg but can hardly explain more energetic explosions and nickel masses higher than 0.1-0.2 M{sub Sun }. These seem to require an alternative SN mechanism.

Calibrating an ellipsometer using x-ray reflectivity

International Nuclear Information System (INIS)

Richter, Andrew; Guico, Rodney; Wang, Jin

2001-01-01

X-ray reflectivity has been used to find the optical refractive index of polymer thin film in order to calibrate a Stokes ellipsometer for film thickness measurements during the deposition procedure. A thin, spun-cast film of poly(tert-butyl acrylate) (PtBA) was made with a film thickness of ∼500 {angstrom}. An x-ray reflectivity measurement was taken and the data were fit to determine the thickness of the PtBA film and the underlying silicon--oxide layer. This measurement was then used to calculate the optical refractive index for PtBA at the ellipsometer wavelength. Using this value for the refractive index subsequently allowed us to determine the film thickness for a series of PtBA films made by using a number of polymer solution concentrations resulting in film thickness ranging from 100 to 1300 {angstrom}. These film thicknesses were found to be generally the same as those found using x-ray reflectivity. The success of this procedure suggests a useful method for calibrating an ellipsometer for fast in-lab measurements, especially on ultrathin films when simultaneous determination of the film thickness and the refractive index is less reliable

Nitric oxide synthase 2 is required for conversion of pro-fibrogenic inflammatory CD133(+) progenitors into F4/80(+) macrophages in experimental autoimmune myocarditis.

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Blyszczuk, Przemyslaw; Berthonneche, Corrine; Behnke, Silvia; Glönkler, Marcel; Moch, Holger; Pedrazzini, Thierry; Lüscher, Thomas F; Eriksson, Urs; Kania, Gabriela

2013-02-01

Experimental autoimmune myocarditis (EAM) model mirrors important mechanisms of inflammatory dilated cardiomyopathy (iDCM). In EAM, inflammatory CD133(+) progenitors are a major cellular source of cardiac myofibroblasts in the post-inflammatory myocardium. We hypothesized that exogenous delivery of macrophage-colony-stimulating factor (M-CSF) can stimulate macrophage lineage differentiation of inflammatory progenitors and, therefore, prevent their naturally occurring myofibroblast fate in EAM. EAM was induced in wild-type (BALB/c) and nitric oxide synthase 2-deficient (Nos2(-/-)) mice and CD133(+) progenitors were isolated from inflamed hearts. In vitro, M-CSF converted inflammatory CD133(+) progenitors into nitric oxide-producing F4/80(+) macrophages and prevented transforming growth factor-β-mediated myofibroblast differentiation. Importantly, only a subset of heart-infiltrating CD133(+) progenitors expresses macrophage-specific antigen F4/80 in EAM. These CD133(+)/F4/80(hi) cells show impaired myofibrogenic potential compared with CD133(+)/F4/80(-) cells. M-CSF treatment of wild-type mice with EAM at the peak of disease markedly increased CD133(+)/F4/80(hi) cells in the myocardium, and CD133(+) progenitors isolated from M-CSF-treated mice failed to differentiate into myofibroblasts. In contrast, M-CSF was not effective in converting CD133(+) progenitors from inflamed hearts of Nos2(-/-) mice into macrophages, and M-CSF treatment did not result in increased CD133(+)/F4/80(hi) cell population in hearts of Nos2(-/-) mice. Accordingly, M-CSF prevented post-inflammatory fibrosis and left ventricular dysfunction in wild-type but not in Nos2(-/-) mice. Active and NOS2-dependent induction of macrophage lineage differentiation abrogates the myofibrogenic potential of heart-infiltrating CD133(+) progenitors. Modulating the in vivo differentiation fate of specific progenitors might become a novel approach for the treatment of inflammatory heart diseases.

Effects of taurine and housing density on renal function in laying hens.

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Ma, Zi-Li; Gao, Yang; Ma, Hai-Tian; Zheng, Liu-Hai; Dai, Bin; Miao, Jin-Feng; Zhang, Yuan-Shu

This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid (taurine) and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups: a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group (C) and a taurine treatment group (T). After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens.

Aging augments renal vasoconstrictor response to orthostatic stress in humans.

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Clark, Christine M; Monahan, Kevin D; Drew, Rachel C

2015-12-15

The ability of the human body to maintain arterial blood pressure (BP) during orthostatic stress is determined by several reflex neural mechanisms. Renal vasoconstriction progressively increases during graded elevations in lower body negative pressure (LBNP). This sympathetically mediated response redistributes blood flow to the systemic circulation to maintain BP. However, how healthy aging affects the renal vasoconstrictor response to LBNP is unknown. Therefore, 10 young (25 ± 1 yr; means ± SE) and 10 older (66 ± 2 yr) subjects underwent graded LBNP (-15 and -30 mmHg) while beat-to-beat renal blood flow velocity (RBFV; Doppler ultrasound), arterial BP (Finometer), and heart rate (HR; electrocardiogram) were recorded. Renal vascular resistance (RVR), an index of renal vasoconstriction, was calculated as mean BP/RBFV. All baseline cardiovascular variables were similar between groups, except diastolic BP was higher in older subjects (P aging augments the renal vasoconstrictor response to orthostatic stress in humans. Copyright © 2015 the American Physiological Society.

Heterogeneity of limbal basal epithelial progenitor cells.

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Hayashida, Yasutaka; Li, Wei; Chen, Ying-Ting; He, Hua; Chen, Szu-yu; Kheirkah, Ahmad; Zhu, Ying-Tien; Matsumoto, Yukihiro; Tseng, Scheffer C G

2010-11-01

Although corneal epithelial stem cells (SCs) are located at the limbus between the cornea and the conjunctiva, not all limbal basal epithelial cells are SCs. Using 2 dispase digestions to remove different amounts of limbal basal epithelial cells for cross-sections, flat mounts, and cytospin preparations, double immunostaining to pancytokeratins (PCK) and vimentin (Vim) identified 3 p63+ epithelial progenitors such as PCK-/Vim+, PCK/Vim, and PCK-/Vim+ and 1 p63+ mesenchymal cell, PCK-/Vim+. PCK-/Vim- progenitors had the smallest cell size were 10-20 times more enriched on collagen I-coated dishes in the 5-minute rapid adherent fraction that contained the highest percentage of p63+ cells but the lowest percentage of cytokeratin12+ cells, and gave rise to high Ki67 labeling and vivid clonal growth. In contrast, PCK+/Vim+ and PCK+/Vim- progenitors were found more in the slow-adherent fraction and yielded poor clonal growth. PCK/Vim progenitors and clusters of PCK-/Vim+ mesenchymal cells, which were neither melanocytes nor Langerhans cells, were located in the limbal basal region. Therefore, differential expression of PCK and Vim helps identify small PCK-/Vim- cells as the most likely candidate for SCs among a hierarchy of heterogeneous limbal basal progenitors, and their close association with PCK-/Vim+ presumed "niche" cells.

Biology and flow cytometry of proangiogenic hematopoietic progenitors cells.

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Rose, Jonathan A; Erzurum, Serpil; Asosingh, Kewal

2015-01-01

During development, hematopoiesis and neovascularization are closely linked to each other via a common bipotent stem cell called the hemangioblast that gives rise to both hematopoietic cells and endothelial cells. In postnatal life, this functional connection between the vasculature and hematopoiesis is maintained by a subset of hematopoietic progenitor cells endowed with the capacity to differentiate into potent proangiogenic cells. These proangiogenic hematopoietic progenitors comprise a specific subset of bone marrow (BM)-derived cells that homes to sites of neovascularization and possess potent paracrine angiogenic activity. There is emerging evidence that this subpopulation of hematopoietic progenitors plays a critical role in vascular health and disease. Their angiogenic activity is distinct from putative "endothelial progenitor cells" that become structural cells of the endothelium by differentiation into endothelial cells. Proangiogenic hematopoietic progenitor cell research requires multidisciplinary expertise in flow cytometry, hematology, and vascular biology. This review provides a comprehensive overview of proangiogenic hematopoietic progenitor cell biology and flow cytometric methods to detect these cells in the peripheral blood circulation and BM. © 2014 International Society for Advancement of Cytometry.

Mechanisms by which heme oxygenase rescue renal dysfunction in obesity

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Joseph Fomusi Ndisang

2014-01-01

Collectively, these data suggest that hemin ameliorates nephropathy by potentiating the expression of proteins of repair/regeneration, abating oxidative/inflammatory mediators, reducing renal histo-pathological lesions, while enhancing nephrin, podocin, podocalyxin, CD2AP and creatinine clearance, with corresponding reduction of albuminuria/proteinuria suggesting improved renal function in hemin-treated ZFs. Importantly, the concomitant potentiation regeneration proteins and podocyte cytoskeletal proteins are novel mechanisms by which hemin rescue nephropathy in obesity.

Reporter-Based Isolation of Developmental Myogenic Progenitors

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Eyemen Kheir

2018-04-01

Full Text Available The formation and activity of mammalian tissues entail finely regulated processes, involving the concerted organization and interaction of multiple cell types. In recent years the prospective isolation of distinct progenitor and stem cell populations has become a powerful tool in the hands of developmental biologists and has rendered the investigation of their intrinsic properties possible. In this protocol, we describe how to purify progenitors with different lineage history and degree of differentiation from embryonic and fetal skeletal muscle by fluorescence-activated cell sorting (FACS. The approach takes advantage of a panel of murine strains expressing fluorescent reporter genes specifically in the myogenic progenitors. We provide a detailed description of the dissection procedures and of the enzymatic dissociation required to maximize the yield of mononucleated cells for subsequent FACS-based purification. The procedure takes ~6–7 h to complete and allows for the isolation and the subsequent molecular and phenotypic characterization of developmental myogenic progenitors.

Inhibition of p38 MAPK attenuates renal atrophy and fibrosis in a murine renal artery stenosis model.

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Wang, Diping; Warner, Gina M; Yin, Ping; Knudsen, Bruce E; Cheng, Jingfei; Butters, Kim A; Lien, Karen R; Gray, Catherine E; Garovic, Vesna D; Lerman, Lilach O; Textor, Stephen C; Nath, Karl A; Simari, Robert D; Grande, Joseph P

2013-04-01

Renal artery stenosis (RAS) is an important cause of chronic renal dysfunction. Recent studies have underscored a critical role for CCL2 (MCP-1)-mediated inflammation in the progression of chronic renal damage in RAS and other chronic renal diseases. In vitro studies have implicated p38 MAPK as a critical intermediate for the production of CCL2. However, a potential role of p38 signaling in the development and progression of chronic renal disease in RAS has not been previously defined. We sought to test the hypothesis that inhibition of p38 MAPK ameliorates chronic renal injury in mice with RAS. We established a murine RAS model by placing a cuff on the right renal artery and treated mice with the p38 inhibitor SB203580 or vehicle for 2 wk. In mice treated with vehicle, the cuffed kidney developed interstitial fibrosis, tubular atrophy, and interstitial inflammation. In mice treated with SB203580, the RAS-induced renal atrophy was reduced (70% vs. 39%, P < 0.05). SB203580 also reduced interstitial inflammation and extracellular matrix deposition but had no effect on the development of hypertension. SB203580 partially blocked the induction of CCL2, CCL7 (MCP-3), CC chemokine receptor 2 (CCR2), and collagen 4 mRNA expression in the cuffed kidneys. In vitro, blockade of p38 hindered both TNF-α and TGF-β-induced CCL2 upregulation. Based on these observations, we conclude that p38 MAPK plays a critical role in the induction of CCL2/CCL7/CCR2 system and the development of interstitial inflammation in RAS.

Renal denervation attenuates NADPH oxidase-mediated oxidative stress and hypertension in rats with hydronephrosis

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Peleli, Maria; Al-Mashhadi, Ammar; Yang, Ting

2016-01-01

Hydronephrosis is associated with development of salt-sensitive hypertension. Studies suggest that increased sympathetic nerve activity (SNA) and oxidative stress play important roles in renovascular hypertension. This study aimed to investigate the link between renal SNA and NADPH oxidase (NOX......) regulation in the development of hypertension in rats with hydronephrosis. Hydronephrosis was induced by partial unilateral ureteral obstruction (PUUO) in young rats. Sham surgery or renal denervation was performed at the same time. Blood pressure was measured during normal, high and low salt diets. Renal...

SUPERNOVA REMNANT PROGENITOR MASSES IN M31

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Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

2012-12-10

Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

Omega 3 fatty acids reduce myeloid progenitor cell frequency in the bone marrow of mice and promote progenitor cell differentiation

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Sollars Vincent E

2009-03-01

Full Text Available Abstract Background Omega 3 fatty acids have been found to inhibit proliferation, induce apoptosis, and promote differentiation in various cell types. The processes of cell survival, expansion, and differentiation are of key importance in the regulation of hematopoiesis. We investigated the role of omega 3 fatty acids in controlling the frequency of various myeloid progenitor cells in the bone marrow of mice. Increased progenitor cell frequency and blocked differentiation are characteristics of hematopoietic disorders of the myeloid lineage, such as myeloproliferative diseases and myeloid leukemias. Results We found that increasing the proportion of omega 3 fatty acids relative to the proportion of omega 6 fatty acids in the diet caused increased differentiation and reduced the frequency of myeloid progenitor cells in the bone marrow of mice. Furthermore, this had no adverse effect on peripheral white blood cell counts. Conclusion Our results indicate that omega 3 fatty acids impact hematopoietic differentiation by reducing myeloid progenitor cell frequency in the bone marrow and promoting progenitor cell differentiation. Further exploration of this discovery could lead to the use of omega 3 fatty acids as a therapeutic option for patients that have various disorders of hematopoiesis.

Progenitor's Signatures in Type Ia Supernova Remnants

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Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.

2013-01-01

The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that

Can preeclampsia be considered a renal compartment syndrome? A hypothesis and analysis of the literature.

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Reuter, David G; Law, Yuk; Levy, Wayne C; Seslar, Stephen P; Zierler, R Eugene; Ferguson, Mark; Chattra, James; McQuinn, Tim; Liu, Lenna L; Terry, Mark; Coffey, Patricia S; Dimer, Jane A; Hanevold, Coral; Flynn, Joseph T; Stapleton, F Bruder

2016-11-01

The morbidity and mortality associated with preeclampsia is staggering. The physiology of the Page kidney, a condition in which increased intrarenal pressure causes hypertension, appears to provide a unifying framework to explain the complex pathophysiology. Page kidney hypertension is renin-mediated acutely and ischemia-mediated chronically. Renal venous outflow obstruction also causes a Page kidney phenomenon, providing a hypothesis for the increased vulnerability of a subset of women who have what we are hypothesizing is a "renal compartment syndrome" due to inadequate ipsilateral collateral renal venous circulation consistent with well-known variation in normal venous anatomy. Dynamic changes in renal venous anatomy and physiology in pregnancy appear to correlate with disease onset, severity, and recurrence. Since maternal recumbent position is well known to affect renal perfusion and since chronic outflow obstruction makes women vulnerable to the ischemic/inflammatory sequelae, heightened awareness of renal compartment syndrome physiology is critical. The anatomic and physiologic insights provide immediate strategies to predict and prevent preeclampsia with straightforward, low-cost interventions that make renewed global advocacy for pregnant women a realistic goal. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

The rebirth of interest in renal tubular function.

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Lowenstein, Jerome; Grantham, Jared J

2016-06-01

The measurement of glomerular filtration rate by the clearance of inulin or creatinine has evolved over the past 50 years into an estimated value based solely on plasma creatinine concentration. We have examined some of the misconceptions and misunderstandings of the classification of renal disease and its course, which have followed this evolution. Furthermore, renal plasma flow and tubular function, which in the past were estimated by the clearance of the exogenous aryl amine, para-aminohippurate, are no longer measured. Over the past decade, studies in experimental animals with reduced nephron mass and in patients with reduced renal function have identified small gut-derived, protein-bound uremic retention solutes ("uremic toxins") that are poorly filtered but are secreted into the lumen by organic anion transporters (OATs) in the proximal renal tubule. These are not effectively removed by conventional hemodialysis or peritoneal dialysis. Residual renal function, urine produced in patients with advanced renal failure or undergoing dialysis treatment, may represent, at least in part, secretion of fluid and uremic toxins, such as indoxyl sulfate, mediated by proximal tubule OATs and might serve as a useful survival function. In light of this new evidence of the physiological role of proximal tubule OATs, we suggest that measurement of renal tubular function and renal plasma flow may be of considerable value in understanding and managing chronic kidney disease. Data obtained in normal subjects indicate that renal plasma flow and renal tubular function might be measured by the clearance of the endogenous aryl amine, hippurate. Copyright © 2016 the American Physiological Society.

Progress of stem/progenitor cell-based therapy for retinal degeneration.

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Tang, Zhimin; Zhang, Yi; Wang, Yuyao; Zhang, Dandan; Shen, Bingqiao; Luo, Min; Gu, Ping

2017-05-10

Retinal degeneration (RD), such as age-related macular degeneration (AMD) and retinitis pigmentosa, is one of the leading causes of blindness. Presently, no satisfactory therapeutic options are available for these diseases principally because the retina and retinal pigmented epithelium (RPE) do not regenerate, although wet AMD can be prevented from further progression by anti-vascular endothelial growth factor therapy. Nevertheless, stem/progenitor cell approaches exhibit enormous potential for RD treatment using strategies mainly aimed at the rescue and replacement of photoreceptors and RPE. The sources of stem/progenitor cells are classified into two broad categories in this review, which are (1) ocular-derived progenitor cells, such as retinal progenitor cells, and (2) non-ocular-derived stem cells, including embryonic stem cells, induced pluripotent stem cells, and mesenchymal stromal cells. Here, we discuss in detail the progress in the study of four predominant stem/progenitor cell types used in animal models of RD. A short overview of clinical trials involving the stem/progenitor cells is also presented. Currently, stem/progenitor cell therapies for RD still have some drawbacks such as inhibited proliferation and/or differentiation in vitro (with the exception of the RPE) and limited long-term survival and function of grafts in vivo. Despite these challenges, stem/progenitor cells represent the most promising strategy for RD treatment in the near future.

Selective uptake of boronophenylalanine by glioma stem/progenitor cells

International Nuclear Information System (INIS)

Sun, Ting; Zhou, Youxin; Xie, Xueshun; Chen, Guilin; Li, Bin; Wei, Yongxin; Chen, Jinming; Huang, Qiang; Du, Ziwei

2012-01-01

The success of boron neutron capture therapy (BNCT) depends on the amount of boron in cells and the tumor/blood and tumor/(normal tissue) boron concentration ratios. For the first time, measurements of boron uptake in both stem/progenitor and differentiated glioma cells were performed along with measurements of boron biodistribution in suitable animal models. In glioma stem/progenitor cells, the selective accumulation of boronophenylalanine (BPA) was lower, and retention of boron after BPA removal was longer than in differentiated glioma cells in vitro. However, boron biodistribution was not statistically significantly different in mice with xenografts. - Highlights: ► Uptake of BPA was analyzed in stem/progenitor and differentiated glioma cells. ► Selective accumulation of BPA was lower in glioma stem/progenitor cells. ► Retention of boron after BPA removal was longer in glioma stem/progenitor cells. ► Boron biodistribution was not statistically different in mice with xenografts.

Direct lineage reprogramming of mouse fibroblasts to functional midbrain dopaminergic neuronal progenitors

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Han-Seop Kim

2014-01-01

Full Text Available The direct lineage reprogramming of somatic cells to other lineages by defined factors has led to innovative cell-fate-change approaches for providing patient-specific cells. Recent reports have demonstrated that four pluripotency factors (Oct4, Sox2, Klf4, and c-Myc are sufficient to directly reprogram fibroblasts to other specific cells, including induced neural stem cells (iNSCs. Here, we show that mouse fibroblasts can be directly reprogrammed into midbrain dopaminergic neuronal progenitors (DPs by temporal expression of the pluripotency factors and environment containing sonic hedgehog and fibroblast growth factor 8. Within thirteen days, self-renewing and functional induced DPs (iDPs were generated. Interestingly, the inhibition of both Jak and Gsk3β notably enhanced the iDP reprogramming efficiency. We confirmed the functionality of the iDPs by showing that the dopaminergic neurons generated from iDPs express midbrain markers, release dopamine, and show typical electrophysiological profiles. Our results demonstrate that the pluripotency factors-mediated direct reprogramming is an invaluable strategy for supplying functional and proliferating iDPs and may be useful for other neural progenitors required for disease modeling and cell therapies for neurodegenerative disorders.

Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors

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Supreet Agarwal

2015-12-01

Full Text Available Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response.

Up-regulation of DRP-3 long isoform during the induction of neural progenitor cells by glutamate treatment in the ex vivo rat retina

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Tokuda, Kazuhiro, E-mail: r502um@yamaguchi-u.ac.jp [Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi (Japan); Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi (Japan); Kuramitsu, Yasuhiro; Byron, Baron; Kitagawa, Takao [Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi (Japan); Tokuda, Nobuko [Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube (Japan); Kobayashi, Daiki; Nagayama, Megumi; Araki, Norie [Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto (Japan); Sonoda, Koh-Hei [Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi (Japan); Nakamura, Kazuyuki [Department of Biochemistry and Functional Proteomics, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi (Japan)

2015-08-07

Glutamate has been shown to induce neural progenitor cells in the adult vertebrate retina. However, protein dynamics during progenitor cell induction by glutamate are not fully understood. To identify specific proteins involved in the process, we employed two-dimensional electrophoresis-based proteomics on glutamate untreated and treated retinal ex vivo sections. Rat retinal tissues were incubated with 1 mM glutamate for 1 h, followed by incubation in glutamate-free media for a total of 24 h. Consistent with prior reports, it was found that mitotic cells appeared in the outer nuclear layer without any histological damage. Immunohistological evaluations and immunoblotting confirmed the emergence of neuronal progenitor cells in the mature retina treated with glutamate. Proteomic analysis revealed the up-regulation of dihydropyrimidinase-related protein 3 (DRP-3), DRP-2 and stress-induced-phosphoprotein 1 (STIP1) during neural progenitor cell induction by glutamate. Moreover, mRNA expression of DRP-3, especially, its long isoform, robustly increased in the treated retina compared to that in the untreated retina. These results may indicate that glutamate induces neural progenitor cells in the mature rat retina by up-regulating the proteins which mediate cell mitosis and neurite growth. - Highlights: • Glutamate induced neuronal progenitor cells in the mature rat retina. • Proteomic analysis revealed the up-regulation of DRP-3, DRP-2 and STIP1. • mRNA expression of DRP-3, especially, its long isoform, robustly increased.

Stanniocalcin-1 Protects a Mouse Model from Renal Ischemia-Reperfusion Injury by Affecting ROS-Mediated Multiple Signaling Pathways.

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Liu, Dajun; Shang, Huiping; Liu, Ying

2016-07-12

Stanniocalcin-1 (STC-1) protects against renal ischemia-reperfusion injury (RIRI). However, the molecular mechanisms remain widely unknown. STC-1 inhibits reactive oxygen species (ROS), whereas most ROS-mediated pathways are associated with ischemic injury. Therefore, to explore the mechanism, the effects of STC-1 on ROS-medicated pathways were studied. Non-traumatic vascular clamps were used to establish RIRI mouse models. The serum levels of STC-1, interleukin-6 (IL-6), interferon (IFN) γ, P53, and capase-3 were measured by ELISA kits. Superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by fluorescence spectrofluorometer. All these molecules changed significantly in a RIRI model mouse when compared with those in a sham control. Kidney cells were isolated from sham and model mice. STC-1 was overexpressed or knockout in these kidney cells. The molecules in ROS-medicated pathways were measured by real-time quantitative PCR and Western blot. The results showed that STC-1 is an effective ROS scavenger. The serum levels of STC-1, MDA and SOD activity were increased while the serum levels of IL-6, iIFN-γ, P53, and capase-3 were decreased in a model group when compared with a sham control (p ROS-mediated molecules. Therefore, STC-1 maybe improve anti-inflammation, anti-oxidant and anti-apoptosis activities by affecting ROS-mediated pathways, especially the phospho-modifications of the respective proteins, resulting in the increase of SOD and reduce of capase-3, p53, IL-6 and IFN-γ.

HDAC inhibition amplifies gap junction communication in neural progenitors: Potential for cell-mediated enzyme prodrug therapy

International Nuclear Information System (INIS)

Khan, Zahidul; Akhtar, Monira; Asklund, Thomas; Juliusson, Bengt; Almqvist, Per M.; Ekstroem, Tomas J.

2007-01-01

Enzyme prodrug therapy using neural progenitor cells (NPCs) as delivery vehicles has been applied in animal models of gliomas and relies on gap junction communication (GJC) between delivery and target cells. This study investigated the effects of histone deacetylase (HDAC) inhibitors on GJC for the purpose of facilitating transfer of therapeutic molecules from recombinant NPCs. We studied a novel immortalized midbrain cell line, NGC-407 of embryonic human origin having neural precursor characteristics, as a potential delivery vehicle. The expression of gap junction protein connexin 43 (C x 43) was analyzed by western blot and immunocytochemistry. While C x 43 levels were decreased in untreated differentiating NGC-407 cells, the HDAC inhibitor 4-phenylbutyrate (4-PB) increased C x 43 expression along with increased membranous deposition in both proliferating and differentiating cells. Simultaneously, Ser 279/282-phosphorylated form of C x 43 was declined in both culture conditions by 4-PB. The 4-PB effect in NGC-407 cells was verified by using HNSC.100 human neural progenitors and Trichostatin A. Improved functional GJC is of imperative importance for therapeutic strategies involving intercellular transport of low molecular-weight compounds. We show here an enhancement by 4-PB, of the functional GJC among NGC-407 cells, as well as between NGC-407 and human glioma cells, as indicated by increased fluorescent dye transfer

Congenital amegakaryocytic thrombocytopenia iPS cells exhibit defective MPL-mediated signaling.

Science.gov (United States)

Hirata, Shinji; Takayama, Naoya; Jono-Ohnishi, Ryoko; Endo, Hiroshi; Nakamura, Sou; Dohda, Takeaki; Nishi, Masanori; Hamazaki, Yuhei; Ishii, Ei-ichi; Kaneko, Shin; Otsu, Makoto; Nakauchi, Hiromitsu; Kunishima, Shinji; Eto, Koji

2013-09-01

Congenital amegakaryocytic thrombocytopenia (CAMT) is caused by the loss of thrombopoietin receptor-mediated (MPL-mediated) signaling, which causes severe pancytopenia leading to bone marrow failure with onset of thrombocytopenia and anemia prior to leukopenia. Because Mpl(-/-) mice do not exhibit the human disease phenotype, we used an in vitro disease tracing system with induced pluripotent stem cells (iPSCs) derived from a CAMT patient (CAMT iPSCs) and normal iPSCs to investigate the role of MPL signaling in hematopoiesis. We found that MPL signaling is essential for maintenance of the CD34+ multipotent hematopoietic progenitor (MPP) population and development of the CD41+GPA+ megakaryocyte-erythrocyte progenitor (MEP) population, and its role in the fate decision leading differentiation toward megakaryopoiesis or erythropoiesis differs considerably between normal and CAMT cells. Surprisingly, complimentary transduction of MPL into normal or CAMT iPSCs using a retroviral vector showed that MPL overexpression promoted erythropoiesis in normal CD34+ hematopoietic progenitor cells (HPCs), but impaired erythropoiesis and increased aberrant megakaryocyte production in CAMT iPSC-derived CD34+ HPCs, reflecting a difference in the expression of the transcription factor FLI1. These results demonstrate that impaired transcriptional regulation of the MPL signaling that normally governs megakaryopoiesis and erythropoiesis underlies CAMT.

Ionizing radiation induces apoptosis in hematopoietic stem and progenitor cells

International Nuclear Information System (INIS)

Meng, A.; Zhou, D.; Geiger, H.; Zant, G.V.

2003-01-01

The aims of this study was to determine if ionizing radiation (IR) induces apoptosis in hematopoietic stem (HSC) and progenitor cells. Lin-cells were isolated from mouse bone marrow (BM) and pretreated with vehicle or 100 μM z-VAD 1 h prior to exposure to 4 Gy IR. The apoptotic and/or necrotic responses of these cells to IR were analyzed by measuring the annexin V and/or 7-AAD staining in HSC and progenitor populations using flow cytometry, and hematopoietic function of these cells was determined by CAFC assay. Exposure of Lin-cells to IR selectively decreased the numbers of HSC and progenitors in association with an increase in apoptosis in a time-dependent manner. Pretreatment of Lin- cells with z-VAD significantly inhibited IR-induced apoptosis and the decrease in the numbers of HSC and progenitors. However, IR alone or in combination with z-VAD did not lead to a significant increase in necrotic cell death in either HSC or progenitors. In addition, pretreatment of BM cells with z-VAD significantly attenuated IR-induced reduction in the frequencies of day-7, -28 and -35 CAFC. Exposure of HSC and progenitors to IR induces apoptosis. The induction of HSC and progenitor apoptosis contributes to IR-induced suppression of their hematopoietic function

THE PROGENITOR OF THE TYPE IIb SN 2008ax REVISITED

International Nuclear Information System (INIS)

Folatelli, Gastón; Bersten, Melina C.; Benvenuto, Omar G.; Kuncarayakti, Hanindyo; Maeda, Keiichi; Nomoto, Ken’ichi

2015-01-01

Hubble Space Telescope observations of the site of the supernova (SN) SN 2008ax obtained in 2011 and 2013 reveal that the possible progenitor object detected in pre-explosion images was in fact multiple. Four point sources are resolved in the new, higher-resolution images. We identify one of the sources with the fading SN. The other three objects are consistent with single supergiant stars. We conclude that their light contaminated the previously identified progenitor candidate. After subtraction of these stars, the progenitor appears to be significantly fainter and bluer than previously measured. Post-explosion photometry at the SN location indicates that the progenitor object has disappeared. If single, the progenitor is compatible with a supergiant star of B to mid-A spectral type, while a Wolf–Rayet (W-R) star would be too luminous in the ultraviolet to account for the observations. Moreover, our hydrodynamical modeling shows that the pre-explosion mass was 4–5 M ⊙ and the radius was 30–50 R ⊙ , which is incompatible with a W-R progenitor. We present a possible interacting binary progenitor computed with our evolutionary models that reproduces all the observational evidence. A companion star as luminous as an O9–B0 main-sequence star may have remained after the explosion

PI3 kinase is important for Ras, MEK and Erk activation of Epo-stimulated human erythroid progenitors

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Schmidt Enrico K

2004-05-01

Full Text Available Abstract Background Erythropoietin is a multifunctional cytokine which regulates the number of erythrocytes circulating in mammalian blood. This is crucial in order to maintain an appropriate oxygen supply throughout the body. Stimulation of primary human erythroid progenitors (PEPs with erythropoietin (Epo leads to the activation of the mitogenic kinases (MEKs and Erks. How this is accomplished mechanistically remained unclear. Results Biochemical studies with human cord blood-derived PEPs now show that Ras and the class Ib enzyme of the phosphatidylinositol-3 kinase (PI3K family, PI3K gamma, are activated in response to minimal Epo concentrations. Surprisingly, three structurally different PI3K inhibitors block Ras, MEK and Erk activation in PEPs by Epo. Furthermore, Erk activation in PEPs is insensitive to the inhibition of Raf kinases but suppressed upon PKC inhibition. In contrast, Erk activation induced by stem cell factor, which activates c-Kit in the same cells, is sensitive to Raf inhibition and insensitive to PI3K and PKC inhibitors. Conclusions These unexpected findings contrast with previous results in human primary cells using Epo at supraphysiological concentrations and open new doors to eventually understanding how low Epo concentrations mediate the moderate proliferation of erythroid progenitors under homeostatic blood oxygen levels. They indicate that the basal activation of MEKs and Erks in PEPs by minimal concentrations of Epo does not occur through the classical cascade Shc/Grb2/Sos/Ras/Raf/MEK/Erk. Instead, MEKs and Erks are signal mediators of PI3K, probably the recently described PI3K gamma, through a Raf-independent signaling pathway which requires PKC activity. It is likely that higher concentrations of Epo that are induced by hypoxia, for example, following blood loss, lead to additional mitogenic signals which greatly accelerate erythroid progenitor proliferation.

Role of NH3 and NH4+ transporters in renal acid-base transport.

Science.gov (United States)

Weiner, I David; Verlander, Jill W

2011-01-01

Renal ammonia excretion is the predominant component of renal net acid excretion. The majority of ammonia excretion is produced in the kidney and then undergoes regulated transport in a number of renal epithelial segments. Recent findings have substantially altered our understanding of renal ammonia transport. In particular, the classic model of passive, diffusive NH3 movement coupled with NH4+ "trapping" is being replaced by a model in which specific proteins mediate regulated transport of NH3 and NH4+ across plasma membranes. In the proximal tubule, the apical Na+/H+ exchanger, NHE-3, is a major mechanism of preferential NH4+ secretion. In the thick ascending limb of Henle's loop, the apical Na+-K+-2Cl- cotransporter, NKCC2, is a major contributor to ammonia reabsorption and the basolateral Na+/H+ exchanger, NHE-4, appears to be important for basolateral NH4+ exit. The collecting duct is a major site for renal ammonia secretion, involving parallel H+ secretion and NH3 secretion. The Rhesus glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), are recently recognized ammonia transporters in the distal tubule and collecting duct. Rhcg is present in both the apical and basolateral plasma membrane, is expressed in parallel with renal ammonia excretion, and mediates a critical role in renal ammonia excretion and collecting duct ammonia transport. Rhbg is expressed specifically in the basolateral plasma membrane, and its role in renal acid-base homeostasis is controversial. In the inner medullary collecting duct (IMCD), basolateral Na+-K+-ATPase enables active basolateral NH4+ uptake. In addition to these proteins, several other proteins also contribute to renal NH3/NH4+ transport. The role and mechanisms of these proteins are discussed in depth in this review.

Hibiscus sabdariffa polyphenols alleviate insulin resistance and renal epithelial to mesenchymal transition: a novel action mechanism mediated by type 4 dipeptidyl peptidase.

Science.gov (United States)

Peng, Chiung-Huei; Yang, Yi-Sun; Chan, Kuei-Chuan; Wang, Chau-Jong; Chen, Mu-Lin; Huang, Chien-Ning

2014-10-08

The epithelial to mesenchymal transition (EMT) is important in renal fibrosis. Ser307 phosphorylation of insulin receptor substrate-1 (IRS-1 (S307)) is a hallmark of insulin resistance. We report that polyphenol extracts of Hibiscus sabdariffa (HPE) ameliorate diabetic nephropathy and EMT. Recently it has been observed that type 4 dipeptidyl peptidase (DPP-4) inhibitor linagliptin is effective for treating type 2 diabetes and albuminuria. We investigated if DPP-4 and insulin resistance are involved in renal EMT and explored the role of HPE. In high glucose-stimulated tubular cells, HPE, like linagliptin, inhibited DPP-4 activation, thereby regulating vimentin (EMT marker) and IRS-1 (S307). IRS-1 knockdown revealed its essential role in mediating downstream EMT. In type 2 diabetic rats, pIRS-1 (S307) abundantly surrounds the tubular region, with increased vimentin in kidney. Both the expressions were reduced by HPE. In conclusion, HPE exerts effects similar to those of linagliptin, which improves insulin resistance and EMT, and could be an adjuvant to prevent diabetic nephropathy.

Retinal progenitor cell xenografts to the pig retina

DEFF Research Database (Denmark)

Warfvinge, Karin; Kiilgaard, Jens Folke; Lavik, Erin B

2005-01-01

To investigate the survival, integration, and differentiation of mouse retinal progenitor cells after transplantation to the subretinal space of adult pigs.......To investigate the survival, integration, and differentiation of mouse retinal progenitor cells after transplantation to the subretinal space of adult pigs....

Endothelial progenitors encapsulated in bioartificial niches are insulated from systemic cytotoxicity and are angiogenesis competent.

Science.gov (United States)

Ratliff, B B; Ghaly, T; Brudnicki, P; Yasuda, K; Rajdev, M; Bank, M; Mares, J; Hatzopoulos, A K; Goligorsky, M S

2010-07-01

Intrinsic stem cells (SC) participate in tissue remodeling and regeneration in various diseases and following toxic insults. Failure of tissue regeneration is in part attributed to lack of SC protection from toxic stress of noxious stimuli, thus prompting intense research efforts to develop strategies for SC protection and functional preservation for in vivo delivery. One strategy is creation of artificial SC niches in an attempt to mimic the requirements of endogenous SC niches by generating scaffolds with properties of extracellular matrix. Here, we investigated the use of hyaluronic acid (HA) hydrogels as an artificial SC niche and examined regenerative capabilities of encapsulated embryonic endothelial progenitor cells (eEPC) in three different in vivo models. Hydrogel-encapsulated eEPC demonstrated improved resistance to toxic insult (adriamycin) in vitro, thus prompting in vivo studies. Implantation of HA hydrogels containing eEPC to mice with adriamycin nephropathy or renal ischemia resulted in eEPC mobilization to injured kidneys (and to a lesser extent to the spleen) and improvement of renal function, which was equal or superior to adoptively transferred EPC by intravenous infusion. In mice with hindlimb ischemia, EPC encapsulated in HA hydrogels dramatically accelerated the recovery of collateral circulation with the efficacy superior to intravenous infusion of EPC. In conclusion, HA hydrogels protect eEPC against adriamycin cytotoxicity and implantation of eEPC encapsulated in HA hydrogels supports renal regeneration in ischemic and cytotoxic (adriamycin) nephropathy and neovascularization of ischemic hindlimb, thus establishing their functional competence and superior capabilities to deliver stem cells stored in and released from this bioartificial niche.

Adult Lung Spheroid Cells Contain Progenitor Cells and Mediate Regeneration in Rodents With Bleomycin-Induced Pulmonary Fibrosis.

Science.gov (United States)

Henry, Eric; Cores, Jhon; Hensley, M Taylor; Anthony, Shirena; Vandergriff, Adam; de Andrade, James B M; Allen, Tyler; Caranasos, Thomas G; Lobo, Leonard J; Cheng, Ke

2015-11-01

Lung diseases are devastating conditions and ranked as one of the top five causes of mortality worldwide according to the World Health Organization. Stem cell therapy is a promising strategy for lung regeneration. Previous animal and clinical studies have focused on the use of mesenchymal stem cells (from other parts of the body) for lung regenerative therapies. We report a rapid and robust method to generate therapeutic resident lung progenitors from adult lung tissues. Outgrowth cells from healthy lung tissue explants are self-aggregated into three-dimensional lung spheroids in a suspension culture. Without antigenic sorting, the lung spheroids recapitulate the stem cell niche and contain a natural mixture of lung stem cells and supporting cells. In vitro, lung spheroid cells can be expanded to a large quantity and can form alveoli-like structures and acquire mature lung epithelial phenotypes. In severe combined immunodeficiency mice with bleomycin-induced pulmonary fibrosis, intravenous injection of human lung spheroid cells inhibited apoptosis, fibrosis, and infiltration but promoted angiogenesis. In a syngeneic rat model of pulmonary fibrosis, lung spheroid cells outperformed adipose-derived mesenchymal stem cells in reducing fibrotic thickening and infiltration. Previously, lung spheroid cells (the spheroid model) had only been used to study lung cancer cells. Our data suggest that lung spheroids and lung spheroid cells from healthy lung tissues are excellent sources of regenerative lung cells for therapeutic lung regeneration. The results from the present study will lead to future human clinical trials using lung stem cell therapies to treat various incurable lung diseases, including pulmonary fibrosis. The data presented here also provide fundamental knowledge regarding how injected stem cells mediate lung repair in pulmonary fibrosis. ©AlphaMed Press.

Diosgenin promotes oligodendrocyte progenitor cell differentiation through estrogen receptor-mediated ERK1/2 activation to accelerate remyelination.

Science.gov (United States)

Xiao, Lin; Guo, Dazhi; Hu, Chun; Shen, Weiran; Shan, Lei; Li, Cui; Liu, Xiuyun; Yang, Wenjing; Zhang, Weidong; He, Cheng

2012-07-01

Differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes is a prerequisite for remyelination after demyelination, and impairment of this process is suggested to be a major reason for remyelination failure. Diosgenin, a plant-derived steroid, has been implicated for therapeutic use in many diseases, but little is known about its effect on the central nervous system. In this study, using a purified rat OPC culture model, we show that diosgenin significantly and specifically promotes OPC differentiation without affecting the viability, proliferation, or migration of OPC. Interestingly, the effect of diosgenin can be blocked by estrogen receptor (ER) antagonist ICI 182780 but not by glucocorticoid and progesterone receptor antagonist RU38486, nor by mineralocorticoid receptor antagonist spirolactone. Moreover, it is revealed that both ER-alpha and ER-beta are expressed in OPC, and diosgenin can activate the extracellular signal-regulated kinase 1/2 (ERK1/2) in OPC via ER. The pro-differentiation effect of diosgenin can also be obstructed by the ERK inhibitor PD98059. Furthermore, in the cuprizone-induced demyelination model, it is demonstrated that diosgenin administration significantly accelerates/enhances remyelination as detected by Luxol fast blue stain, MBP immunohistochemistry and real time RT-PCR. Diosgenin also increases the number of mature oligodendrocytes in the corpus callosum while it does not affect the number of OPCs. Taking together, our results suggest that diosgenin promotes the differentiation of OPC into mature oligodendrocyte through an ER-mediated ERK1/2 activation pathway to accelerate remyelination, which implicates a novel therapeutic usage of this steroidal natural product in demyelinating diseases such as multiple sclerosis (MS). Copyright © 2012 Wiley Periodicals, Inc.

Basic fibroblast growth factor is pro-adipogenic in rat skeletal muscle progenitor clone, 2G11 cells.

Science.gov (United States)

Nakano, Shin-ichi; Nakamura, Katsuyuki; Teramoto, Naomi; Yamanouchi, Keitaro; Nishihara, Masugi

2016-01-01

Intramuscular adipose tissue (IMAT) formation is a hallmark of marbling in cattle. IMAT is considered to originate from skeletal muscle progenitor cells with adipogenic potential. However, the mechanism involved in IMAT formation from these progenitor cells in vivo remains unclear. In the present study, among the growth factors tested, which were known to be expressed in skeletal muscle, we found only basic fibroblast growth factor (bFGF) has a pro-adipogenic effect on skeletal muscle derived adipogenic progenitor clone, 2G11 cells. Pre-exposure of 2G11 cells to bFGF did not affect initial gene expressions of CCAAT/enhancer-binding protein (C/EBP)β and C/EBPδ, while resulting in an enhancement of subsequent expressions of C/EBPα and proliferator-activated receptor gamma (PPARγ) during adipogenesis, indicating that bFGF is acting on the transcriptional regulation of C/EBPα and PPARγ. In addition, the effect of bFGF is mediated via two types of FGF receptor (FGFR) isoforms: FGFR1 and FGFR2 IIIc, and both receptors are prerequisite for bFGF to express its pro-adipogenic effect. These results suggest that bFGF plays an important role as a key trigger of IMAT formation in vivo. © 2015 Japanese Society of Animal Science.

Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells

International Nuclear Information System (INIS)

Jantzen, Kim; Møller, Peter; Karottki, Dorina Gabriela; Olsen, Yulia; Bekö, Gabriel; Clausen, Geo; Hersoug, Lars-Georg; Loft, Steffen

2016-01-01

Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related to leukocyte-mediated oxidative stress. The study utilized a cross sectional design performed in 58 study participants from a larger cohort. Levels of circulating endothelial progenitor cells, defined as either late (CD34 + KDR + cells) or early (CD34 + CD133 + KDR + cells) subsets were measured using polychromatic flow cytometry. We additionally measured production of reactive oxygen species in leukocyte subsets (lymphocytes, monocytes and granulocytes) by flow cytometry using intracellular 2′,7′-dichlorofluoroscein. The measurements encompassed both basal levels of reactive oxygen species production and capacity for reactive oxygen species production for each leukocyte subset. We found that the late endothelial progenitor subset was negatively associated with levels of ultrafine particles measured within the participant residences and with reactive oxygen species production capacity in lymphocytes. Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate that exposure to fine and ultrafine particles derived from indoor sources may have adverse effects on human vascular health.

Tubular and endothelial chimerism in renal allografts using fluorescence and chromogenic in situ hybridization (FISH, CISH) technology.

Science.gov (United States)

Varga, Zsuzsanna; Gaspert, Ariana; Behnke, Silvia; von Teichman, Adriana; Fritzsche, Florian; Fehr, Thomas

2012-04-01

The role of endothelial and tubular chimerism in renal allograft adaptation and rejection varies in different studies. We addressed the correlation between different clinico-pathological settings and sex-chromosomal endothelial and/or tubular chimerism in renal allografts. We examined the presence or absence of the X and Y chromosomes by fluorescence and chromogenic in situ hybridization (FISH, CISH) methodology on paraffin embedded kidney biopsies in 16 gender mismatched renal transplants (1 to 12 years post-transplantation). Twelve patients were male, four female. Four groups were selected: (i) Vascular calcineurin inhibitor toxicity without rejection; (ii) T-cell mediated vascular rejection; (iii) antibody mediated rejection; and (iv) C4d-positivity in AB0-incompatible transplants with or without rejection. Twelve non-transplant kidney biopsies (8 female, 4 male) were used as controls. Tubular chimerism was detected more frequently (69%) than endothelial chimerism (12%) in renal transplants. One of 12 control patients had tubular and endothelial chimeric cells (8%). The Y chromosome occurred in 8/12 male recipients (67%) in tubular epithelial cells and in 5/12 male recipients (42%) in endothelial cells. Double X chromosomes were detected in 3/4 female recipients in tubular epithelium. Tubular chimerism occurred more often with endothelial chimerism and capillaritis without correlation with other parameters, such as rejection. Combined Y chromosomal tubular and lymphatic endothelial chimerism correlated with T-cell mediated vascular rejection in two out of three patients (66%). Combined Y chromosomal tubular and peritubular capillary chimerism correlated with antibody mediated C4d+ rejection in one out of two patients (50%). Tubular and/or endothelial chimerism occur frequently in gender mismatched renal allografts and, when combined, this is associated with T-cell mediated rejection. © 2012 The Authors. Pathology International © 2012 Japanese Society of

Cdc42 controls progenitor cell differentiation and beta-catenin turnover in skin

DEFF Research Database (Denmark)

Wu, Xunwei; Quondamatteo, Fabio; Lefever, Tine

2006-01-01

for differentiation of skin progenitor cells into HF lineage and that it regulates the turnover of beta-catenin. In the absence of Cdc42, degradation of beta-catenin was increased corresponding to a decreased phosphorylation of GSK3beta at Ser 9 and an increased phosphorylation of axin, which is known to be required...... for binding of beta-catenin to the degradation machinery. Cdc42-mediated regulation of beta-catenin turnover was completely dependent on PKCzeta, which associated with Cdc42, Par6, and Par3. These data suggest that Cdc42 regulation of beta-catenin turnover is important for terminal differentiation of HF...

Taurine Ameliorates Renal Oxidative Damage and Thyroid Dysfunction in Rats Chronically Exposed to Fluoride.

Science.gov (United States)

Adedara, Isaac A; Ojuade, Temini Jesu D; Olabiyi, Bolanle F; Idris, Umar F; Onibiyo, Esther M; Ajeigbe, Olufunke F; Farombi, Ebenezer O

2017-02-01

Excessive exposure to fluoride poses several detrimental effects to human health particularly the kidney which is a major organ involved in its elimination from the body. The influence of taurine on fluoride-induced renal toxicity was investigated in a co-exposure paradigm for 45 days using five groups of eight rats each. Group I rats received normal drinking water alone, group II rats were exposed to sodium fluoride (NaF) in drinking water at 15 mg/L alone, group III received taurine alone at a dose of 200 mg/kg group IV rats were co-administered with NaF and taurine (100 mg/kg), while group V rats were co-administered with NaF and taurine (200 mg/kg). Administration of taurine significantly reversed the fluoride-mediated decrease in absolute weight and organo-somatic index of the kidney in the exposed rats. Taurine significantly prevented fluoride-induced elevation in plasma urea and creatinine levels in the exposed rats. Moreover, taurine restored fluoride-mediated decrease in the circulatory concentrations of triiodothyronine, thyroxine, and the ratio of triiodothyronine to thyroxine. Taurine ameliorated fluoride-mediated decrease in renal antioxidant status by significantly enhancing the antioxidant enzyme activities as well as glutathione level in the exposed rats. Additionally, taurine inhibited fluoride-induced renal oxidative damage by markedly decreasing the hydrogen peroxide and malondialdehyde levels as well as improved the kidney architecture in the treated rats. Collectively, taurine protected against fluoride-induced renal toxicity via enhancement of thyroid gland function, renal antioxidant status, and histology in rats.

FGF8 signaling sustains progenitor status and multipotency of cranial neural crest-derived mesenchymal cells in vivo and in vitro

Science.gov (United States)

Shao, Meiying; Liu, Chao; Song, Yingnan; Ye, Wenduo; He, Wei; Yuan, Guohua; Gu, Shuping; Lin, Congxin; Ma, Liang; Zhang, Yanding; Tian, Weidong; Hu, Tao; Chen, YiPing

2015-01-01

The cranial neural crest (CNC) cells play a vital role in craniofacial development and regeneration. They are multi-potent progenitors, being able to differentiate into various types of tissues. Both pre-migratory and post-migratory CNC cells are plastic, taking on diverse fates by responding to different inductive signals. However, what sustains the multipotency of CNC cells and derivatives remains largely unknown. In this study, we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro. We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status. CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival, proliferation, and multi-potent differentiation capability in cell cultures. Remarkably, exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis. Furthermore, FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro. Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells, implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration. PMID:26243590

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.

Alcohol consumption negates estrogen-mediated myocardial repair in ovariectomized mice by inhibiting endothelial progenitor cell mobilization and function.

Science.gov (United States)

Mackie, Alexander R; Krishnamurthy, Prasanna; Verma, Suresh K; Thorne, Tina; Ramirez, Veronica; Qin, Gangjian; Abramova, Tatiana; Hamada, Hiromichi; Losordo, Douglas W; Kishore, Raj

2013-06-21

We have shown previously that estrogen (estradiol, E2) supplementation enhances voluntary alcohol consumption in ovariectomized female rodents and that increased alcohol consumption impairs ischemic hind limb vascular repair. However, the effect of E2-induced alcohol consumption on post-infarct myocardial repair and on the phenotypic/functional properties of endothelial progenitor cells (EPCs) is not known. Additionally, the molecular signaling of alcohol-estrogen interactions remains to be elucidated. This study examined the effect of E2-induced increases in ethanol consumption on post-infarct myocardial function/repair. Ovariectomized female mice, implanted with 17β-E2 or placebo pellets were given access to alcohol for 6 weeks and subjected to acute myocardial infarction. Left ventricular functions were consistently depressed in mice consuming ethanol compared with those receiving only E2. Alcohol-consuming mice also displayed significantly increased infarct size and reduced capillary density. Ethanol consumption also reduced E2-induced mobilization and homing of EPCs to injured myocardium compared with the E2-alone group. In vitro, exposure of EPCs to ethanol suppressed E2-induced proliferation, survival, and migration and markedly altered E2-induced estrogen receptor-dependent cell survival signaling and gene expression. Furthermore, ethanol-mediated suppression of EPC biology was endothelial nitric oxide synthase-dependent because endothelial nitric oxide synthase-null mice displayed an exaggerated response to post-acute myocardial infarction left ventricular functions. These data suggest that E2 modulation of alcohol consumption, and the ensuing EPC dysfunction, may negatively compete with the beneficial effects of estrogen on post-infarct myocardial repair.

Impact on creatinine renal clearance by the interplay of multiple renal transporters: a case study with INCB039110.

Science.gov (United States)

Zhang, Yan; Warren, Mark S; Zhang, Xuexiang; Diamond, Sharon; Williams, Bill; Punwani, Naresh; Huang, Jane; Huang, Yong; Yeleswaram, Swamy

2015-04-01

Serum creatinine is commonly used as a marker of renal function, but increases in serum creatinine might not represent changes in glomerular filtration rate (GFR). INCB039110 (2-(3-(4-(7H-pyrrolo[2,3-day]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(1-(3-fluoro-2-(trifluoromethyl)isonicotinoyl)piperidin-4-yl)azetidin-3-yl)acetonitrile) is an inhibitor of the Janus kinases (JAKs) with selectivity for JAK1. In a phase 1 study, a modest and reversible increase in serum creatinine was observed after treatment with INCB039110. However, a dedicated renal function study with INCB039110, assessed by iohexol plasma clearance, conducted in healthy volunteers indicated no change in GFR. In vitro studies were therefore conducted to investigate the interaction of INCB039110 with five transporters that are likely involved in the renal clearance of creatinine. Cell systems expressing individual or multiple transporters were used, including a novel quintuple-transporter model OAT2/OCT2/OCT3/MATE1/MATE2-K. INCB039110 potently inhibited OCT2-mediated uptake of creatinine as well as MATE1-/MATE2-K-mediated efflux of creatinine. Given the interactions of INCB039110 with multiple transporters affecting creatinine uptake and efflux, an integrated system expressing all five transporters was sought; in that system, INCB039110 caused a dose-dependent decrease in transcellular transport of creatinine with weaker net inhibition compared with the effects on individual transporters. In summary, a molecular mechanism for the increase in serum creatinine by INCB039110 has been established. These studies also underline the limitations of using serum creatinine as a marker of renal function. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Role of mobile passenger lymphocytes in the rejection of renal and cardiac allografts in the rat. A passenger lymphocyte-mediated graft-versus-host reaction amplifies the host response

International Nuclear Information System (INIS)

van Vrieshilfgaarde, R.; Hermans, P.; Terpstra, J.L.; van Breda Viresman, P.J.

1980-01-01

It is demonstrated that passenger lymphocytes migrate out of rat renal allografts into host spleens in a radioresistant fashion. These mobile passenger lymphocytes within BN kidney and heart transplants are immunocompetent, since they elicit a graft-versus-host (GVH) reaction in the spleens of (LEW x BN)F2 hybrid hosts. The greater GVH reaction in (LEW x BN)F1 recipients of BN kidneys reflects the greater number of mobile passenger lymphocytes in the kidney when compared to the heart. The mobile passenger lymphocytes within BN renal allografts also cause a proliferative response in the spleens of the LEW hosts as well as an accelerated rejection of BN renal allografts when compared to BN cardiac allografts, for the differences between BN kidney and heart, both in terms of splenomegaly elicited in LEW as well as tempo of rejection, are abolished by total body x-irradiation of the donor with 900 rad. Results indicate that a mobile passenger lymphocyte mediated GVH reaction in the central lymphoid organs of the host augments the host response to allogenic kidneys and contributes materially to first-set renal allograft rejection; this GVH reaction on the other hand is not conspicuously present in LEW recipients of BN cardiac allografts and has therefore little effect on first-set cardiac allograft rejection

THE PROGENITOR OF THE TYPE IIb SN 2008ax REVISITED

Energy Technology Data Exchange (ETDEWEB)

Folatelli, Gastón; Bersten, Melina C.; Benvenuto, Omar G. [Instituto de Astrofísica de La Plata (Argentina); Kuncarayakti, Hanindyo [Millennium Institute of Astrophysics (MAS), Casilla 36-D, Santiago (Chile); Maeda, Keiichi; Nomoto, Ken’ichi, E-mail: gaston@fcaglp.unlp.edu.ar [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

2015-10-01

Hubble Space Telescope observations of the site of the supernova (SN) SN 2008ax obtained in 2011 and 2013 reveal that the possible progenitor object detected in pre-explosion images was in fact multiple. Four point sources are resolved in the new, higher-resolution images. We identify one of the sources with the fading SN. The other three objects are consistent with single supergiant stars. We conclude that their light contaminated the previously identified progenitor candidate. After subtraction of these stars, the progenitor appears to be significantly fainter and bluer than previously measured. Post-explosion photometry at the SN location indicates that the progenitor object has disappeared. If single, the progenitor is compatible with a supergiant star of B to mid-A spectral type, while a Wolf–Rayet (W-R) star would be too luminous in the ultraviolet to account for the observations. Moreover, our hydrodynamical modeling shows that the pre-explosion mass was 4–5 M{sub ⊙} and the radius was 30–50 R{sub ⊙}, which is incompatible with a W-R progenitor. We present a possible interacting binary progenitor computed with our evolutionary models that reproduces all the observational evidence. A companion star as luminous as an O9–B0 main-sequence star may have remained after the explosion.

Atrial Natriuretic Peptide Accelerates Human Endothelial Progenitor Cell-Stimulated Cutaneous Wound Healing and Angiogenesis.

Science.gov (United States)

Lee, Tae Wook; Kwon, Yang Woo; Park, Gyu Tae; Do, Eun Kyoung; Yoon, Jung Won; Kim, Seung-Chul; Ko, Hyun-Chang; Kim, Moon-Bum; Kim, Jae Ho

2018-05-26

Atrial natriuretic peptide (ANP) is a powerful vasodilating peptide secreted by cardiac muscle cells, and endothelial progenitor cells (EPCs) have been reported to stimulate cutaneous wound healing by mediating angiogenesis. To determine whether ANP can promote the EPC-mediated repair of injured tissues, we examined the effects of ANP on the angiogenic properties of EPCs and on cutaneous wound healing. In vitro, ANP treatment enhanced the migration, proliferation, and endothelial tube-forming abilities of EPCs. Furthermore, small interfering RNA-mediated silencing of natriuretic peptide receptor-1, which is a receptor for ANP, abrogated ANP-induced migration, tube formation, and proliferation of EPCs. In a murine cutaneous wound model, administration of either ANP or EPCs had no significant effect on cutaneous wound healing or angiogenesis in vivo, whereas the co-administration of ANP and EPCs synergistically potentiated wound healing and angiogenesis. In addition, ANP promoted the survival and incorporation of transplanted EPCs into newly formed blood vessels in wounds. These results suggest ANP accelerates EPC-mediated cutaneous wound healing by promoting the angiogenic properties and survival of transplanted EPCs. This article is protected by copyright. All rights reserved. © 2018 by the Wound Healing Society.

Renal sympathetic denervation in hypertension.

Science.gov (United States)

Doumas, Michael; Faselis, Charles; Papademetriou, Vasilios

2011-11-01

Despite the abundance of antihypertensive drugs, resistant hypertension remains a major clinical problem. Recent technological advances render interventional management of resistant hypertension one of the hottest topics in the hypertension field. The aim of this review is to present the pathophysiologic background and the mechanisms mediating blood pressure reduction after renal sympathetic denervation, to analyze recent findings with this fascinating approach and to critically suggest future research directions. Catheter-based, ablation-induced renal sympathetic denervation was initially studied in 45 patients with resistant hypertension in a proof-of-concept study. Impressive blood pressure reductions of about 30/15  mmHg were achieved at 6 months, without serious complications. A second, controlled, randomized (but not blinded) study confirmed the results, verifying the efficacy and safety of the procedure. A recent report revealed the 2-year durability of blood pressure reduction. Data published so far indicate that ablation-induced renal denervation is a feasible, effective, and well tolerated interventional approach for the management of resistant hypertension. The groundbreaking studies of renal denervation in drug-resistant hypertension pave the way for further research in other disease conditions in which sympathetic overactivity seems to play a critical role. This initial wave of enthusiasm needs to be followed by rigorous investigation, for the proper identification of the potential and the limitations, indications, and contraindications of this approach.

Renal ischemia-reperfusion injury and adenosine 2A receptor-mediated tissue protection: the role of CD4+ T cells and IFN-gamma.

Science.gov (United States)

Day, Yuan-Ji; Huang, Liping; Ye, Hong; Li, Li; Linden, Joel; Okusa, Mark D

2006-03-01

A(2A) adenosine receptor (A(2A)R)-expressing bone marrow (BM)-derived cells contribute to the renal protective effect of A(2A) agonists in renal ischemia-reperfusion injury (IRI). We performed IRI in mice lacking T and B cells to determine whether A(2A)R expressed in CD4+ cells mediate protection from IRI. Rag-1 knockout (KO) mice were protected in comparison to wild-type (WT) mice when subjected to IRI. ATL146e, a selective A(2A) agonist, did not confer additional protection. IFN-gamma is an important early signal in IRI and is thought to contribute to reperfusion injury. Because IFN-gamma is produced by kidney cells and T cells we performed IRI in BM chimeras in which the BM of WT mice was reconstituted with BM from IFN-gamma KO mice (IFN-gamma KO-->WT chimera). We observed marked reduction in IRI in comparison to WT-->WT chimeras providing additional indirect support for the role of T cells. To confirm the role of CD4+ A(2A)R in mediating protection from IRI, Rag-1 KO mice were subjected to ischemia-reperfusion. The protection observed in Rag-1 KO mice was reversed in Rag-1 KO mice that were adoptively transferred WT CD4+ cells (WT CD4+-->Rag-1 KO) or A(2A) KO CD4+ cells (A(2A) KO CD4+-->Rag-1 KO). ATL146e reduced injury in WT CD4+-->Rag-1 KO mice but not in A(2A) KO CD4+-->Rag-1 KO mice. Rag-1 KO mice reconstituted with CD4+ cells derived from IFN-gamma KO mice (IFN-gamma CD4+-->Rag-1 KO) were protected from IRI; ATL146e conferred no additional protection. These studies demonstrate that CD4+ IFN-gamma contributes to IRI and that A(2A) agonists mediate protection from IRI through action on CD4+ cells.

Reversible immortalisation enables genetic correction of human muscle progenitors and engineering of next-generation human artificial chromosomes for Duchenne muscular dystrophy.

Science.gov (United States)

Benedetti, Sara; Uno, Narumi; Hoshiya, Hidetoshi; Ragazzi, Martina; Ferrari, Giulia; Kazuki, Yasuhiro; Moyle, Louise Anne; Tonlorenzi, Rossana; Lombardo, Angelo; Chaouch, Soraya; Mouly, Vincent; Moore, Marc; Popplewell, Linda; Kazuki, Kanako; Katoh, Motonobu; Naldini, Luigi; Dickson, George; Messina, Graziella; Oshimura, Mitsuo; Cossu, Giulio; Tedesco, Francesco Saverio

2018-02-01

Transferring large or multiple genes into primary human stem/progenitor cells is challenged by restrictions in vector capacity, and this hurdle limits the success of gene therapy. A paradigm is Duchenne muscular dystrophy (DMD), an incurable disorder caused by mutations in the largest human gene: dystrophin. The combination of large-capacity vectors, such as human artificial chromosomes (HACs), with stem/progenitor cells may overcome this limitation. We previously reported amelioration of the dystrophic phenotype in mice transplanted with murine muscle progenitors containing a HAC with the entire dystrophin locus (DYS-HAC). However, translation of this strategy to human muscle progenitors requires extension of their proliferative potential to withstand clonal cell expansion after HAC transfer. Here, we show that reversible cell immortalisation mediated by lentivirally delivered excisable hTERT and Bmi1 transgenes extended cell proliferation, enabling transfer of a novel DYS-HAC into DMD satellite cell-derived myoblasts and perivascular cell-derived mesoangioblasts. Genetically corrected cells maintained a stable karyotype, did not undergo tumorigenic transformation and retained their migration ability. Cells remained myogenic in vitro (spontaneously or upon MyoD induction) and engrafted murine skeletal muscle upon transplantation. Finally, we combined the aforementioned functions into a next-generation HAC capable of delivering reversible immortalisation, complete genetic correction, additional dystrophin expression, inducible differentiation and controllable cell death. This work establishes a novel platform for complex gene transfer into clinically relevant human muscle progenitors for DMD gene therapy. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Endothelial progenitor cells in chronic obstructive pulmonary disease and emphysema

Science.gov (United States)

Tracy, Russell P.; Parikh, Megha A.; Hoffman, Eric A.; Shimbo, Daichi; Austin, John H. M.; Smith, Benjamin M.; Hueper, Katja; Vogel-Claussen, Jens; Lima, Joao; Gomes, Antoinette; Watson, Karol; Kawut, Steven; Barr, R. Graham

2017-01-01

Endothelial injury is implicated in the pathogenesis of COPD and emphysema; however the role of endothelial progenitor cells (EPCs), a marker of endothelial cell repair, and circulating endothelial cells (CECs), a marker of endothelial cell injury, in COPD and its subphenotypes is unresolved. We hypothesized that endothelial progenitor cell populations would be decreased in COPD and emphysema and that circulating endothelial cells would be increased. Associations with other subphenotypes were examined. The Multi-Ethnic Study of Atherosclerosis COPD Study recruited smokers with COPD and controls age 50–79 years without clinical cardiovascular disease. Endothelial progenitor cell populations (CD34+KDR+ and CD34+KDR+CD133+ cells) and circulating endothelial cells (CD45dimCD31+CD146+CD133-) were measured by flow cytometry. COPD was defined by standard spirometric criteria. Emphysema was assessed qualitatively and quantitatively on CT. Full pulmonary function testing and expiratory CTs were measured in a subset. Among 257 participants, both endothelial progenitor cell populations, and particularly CD34+KDR+ endothelial progenitor cells, were reduced in COPD. The CD34+KDR+CD133+ endothelial progenitor cells were associated inversely with emphysema extent. Both endothelial progenitor cell populations were associated inversely with extent of panlobular emphysema and positively with diffusing capacity. Circulating endothelial cells were not significantly altered in COPD but were inversely associated with pulmonary microvascular blood flow on MRI. There was no consistent association of endothelial progenitor cells or circulating endothelial cells with measures of gas trapping. These data provide evidence that endothelial repair is impaired in COPD and suggest that this pathological process is specific to emphysema. PMID:28291826

Chronic Antibody-Mediated Rejection in Nonhuman Primate Renal Allografts: Validation of Human Histological and Molecular Phenotypes.

Science.gov (United States)

Adam, B A; Smith, R N; Rosales, I A; Matsunami, M; Afzali, B; Oura, T; Cosimi, A B; Kawai, T; Colvin, R B; Mengel, M

2017-11-01

Molecular testing represents a promising adjunct for the diagnosis of antibody-mediated rejection (AMR). Here, we apply a novel gene expression platform in sequential formalin-fixed paraffin-embedded samples from nonhuman primate (NHP) renal transplants. We analyzed 34 previously described gene transcripts related to AMR in humans in 197 archival NHP samples, including 102 from recipients that developed chronic AMR, 80 from recipients without AMR, and 15 normal native nephrectomies. Three endothelial genes (VWF, DARC, and CAV1), derived from 10-fold cross-validation receiver operating characteristic curve analysis, demonstrated excellent discrimination between AMR and non-AMR samples (area under the curve = 0.92). This three-gene set correlated with classic features of AMR, including glomerulitis, capillaritis, glomerulopathy, C4d deposition, and DSAs (r = 0.39-0.63, p < 0.001). Principal component analysis confirmed the association between three-gene set expression and AMR and highlighted the ambiguity of v lesions and ptc lesions between AMR and T cell-mediated rejection (TCMR). Elevated three-gene set expression corresponded with the development of immunopathological evidence of rejection and often preceded it. Many recipients demonstrated mixed AMR and TCMR, suggesting that this represents the natural pattern of rejection. These data provide NHP animal model validation of recent updates to the Banff classification including the assessment of molecular markers for diagnosing AMR. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Factors promoting development of renal tubulointerstitial lesions in patients with diabetes mellitus

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Minara Shamkhalovna Shamkhalova

2010-09-01

Full Text Available Aim. To identify profibrogenic mediators, markers of endothelial dysfunction and hemostasis in patients with diabetes mellitus (DM and chronickidney disease (CKD. Materials and methods. The study included 120 patients with DM and 20 age-matched normotensive subjects without DM showing the glomerularfiltration rate (GFR > 60 ml/min/1.73 m3. Four groups of patients were distinguished: 1 - DM2 patients without renal pathology (n=33, 2 - DM2 patients with diabetic nephropathy (n=24, 3 - DM2 patients with ischemic nephropathy (IN (n=33 verified by contrast visualization techniques(multispiral CM of abdominal aorta and renal arteries, abdominal angiography of renal arteries or MR angiography of renal arteries and abdominal aorta, 4 - DM1 patients with DN (n=30. Clinical examination included assessment of complaints, analysis of medical history of the main diseaseand concomitant disorders, determination of the main clinical and biochemical characteristics of blood and urine, measurement of НbА1с and 24-hralbuminuria (AU by standard methods, estimation of GFR by the MDRD formula, ECG, echocardiography, 24-hr AP monitoring, counseling bycardiologist and ophthalmologist (fundal examination by ophthalmoscopy. Standard kits were used to detect profibrogenic mediators and markersof endothelial dysfunction including transforming growth factor-beta (TGF-b, angiotensin II (AT II, monocyte chemoattractant protein (MCP-1,regulated on activation normal T cell expressed and secreted (RANTES, adhesion factors (intracellular adhesion molecule (ICAM-1, vascular celladhesion molecule (VCAM-1 vascular endothelial growth factor (VEGF, interleukin-6 (IL-6, asymmetric dimethylargnine (ADMA, homocysteine(HCYST, metalloproteinases (MMP, von Willebrand factor (vWF, plasminogen activator inhibitor (PAI-I. Results. DM patients with CKD had elevated blood profibrogenic cytokine (MCP-1, TGF-1b, IL-6 and extracellular matrix degradation factor(MMP-9 levels compared with

Central Methysergide Prevents Renal Sympathoinhibition and Bradycardia during Hypotensive Hemorrhage

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Veelken, Roland; Johnson, Kim; Scrogin, Karie E.

1998-01-01

Central methysergide prevents renal sympathoinhibition and bradycardia during hypotensive hemorrhage. Mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were measured in conscious rats during either hemorrhage or cardiopulmonary receptor stimulation with phenylbiguanide (PBG) after intracerebroventricular injection of the 5-HT1/5-HT2-receptor antagonist, methysergide (40 microg). Progressive hemorrhage caused an initial rise (109 +/- 33%) followed by a fall in RSNA (-60 +/- 7%) and a fall in HR (-126 +/- 7 beats/min). Methysergide delayed the hypotension and prevented both the sympathoinhibitory and bradycardic responses to hemorrhage. Systemic 5-HT3-receptor blockade did not influence responses to hemorrhage. The PBG infusion caused transient depressor(-25 +/- 6 mmHg), bradycardic (-176 +/- 40 beats/min), and renal sympathostimulatory (182 +/-47% baseline) responses that were not affected by central methysergide (-20 +/- 6 mmHg, -162 +/- 18 beats/min, 227 +/- 46% baseline). These data indicate that a central serotonergic receptor-mediated component contributes to the sympathoinhibitory and bradycardic responses to hypotensive hemorrhage in conscious rats. Furthermore, the same central 5-HT-receptor populations involved in reflex responses to hypotensive hemorrhage probably do not mediate the sympathoinhibitory response to cardiopulmonary chemosensitive 5-HT3 receptors.

Acid-base status determines the renal expression of Ca2+ and Mg2+ transport proteins.

NARCIS (Netherlands)

Nijenhuis, T.; Renkema, K.Y.; Hoenderop, J.G.J.; Bindels, R.J.M.

2006-01-01

Chronic metabolic acidosis results in renal Ca2+ and Mg2+ wasting, whereas chronic metabolic alkalosis is known to exert the reverse effects. It was hypothesized that these adaptations are mediated at least in part by the renal Ca2+ and Mg2+ transport proteins. The aim of this study, therefore, was

Mammalian neurogenesis requires Treacle-Plk1 for precise control of spindle orientation, mitotic progression, and maintenance of neural progenitor cells.

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Daisuke Sakai

Full Text Available The cerebral cortex is a specialized region of the brain that processes cognitive, motor, somatosensory, auditory, and visual functions. Its characteristic architecture and size is dependent upon the number of neurons generated during embryogenesis and has been postulated to be governed by symmetric versus asymmetric cell divisions, which mediate the balance between progenitor cell maintenance and neuron differentiation, respectively. The mechanistic importance of spindle orientation remains controversial, hence there is considerable interest in understanding how neural progenitor cell mitosis is controlled during neurogenesis. We discovered that Treacle, which is encoded by the Tcof1 gene, is a novel centrosome- and kinetochore-associated protein that is critical for spindle fidelity and mitotic progression. Tcof1/Treacle loss-of-function disrupts spindle orientation and cell cycle progression, which perturbs the maintenance, proliferation, and localization of neural progenitors during cortical neurogenesis. Consistent with this, Tcof1(+/- mice exhibit reduced brain size as a consequence of defects in neural progenitor maintenance. We determined that Treacle elicits its effect via a direct interaction with Polo-like kinase1 (Plk1, and furthermore we discovered novel in vivo roles for Plk1 in governing mitotic progression and spindle orientation in the developing mammalian cortex. Increased asymmetric cell division, however, did not promote increased neuronal differentiation. Collectively our research has therefore identified Treacle and Plk1 as novel in vivo regulators of spindle fidelity, mitotic progression, and proliferation in the maintenance and localization of neural progenitor cells. Together, Treacle and Plk1 are critically required for proper cortical neurogenesis, which has important implications in the regulation of mammalian brain size and the pathogenesis of congenital neurodevelopmental disorders such as microcephaly.

Endoplasmic Reticulum Chaperon Tauroursodeoxycholic Acid Attenuates Aldosterone-Infused Renal Injury

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Honglei Guo

2016-01-01

Full Text Available Aldosterone (Aldo is critically involved in the development of renal injury via the production of reactive oxygen species and inflammation. Endoplasmic reticulum (ER stress is also evoked in Aldo-induced renal injury. In the present study, we investigated the role of ER stress in inflammation-mediated renal injury in Aldo-infused mice. C57BL/6J mice were randomized to receive treatment for 4 weeks as follows: vehicle infusion, Aldo infusion, vehicle infusion plus tauroursodeoxycholic acid (TUDCA, and Aldo infusion plus TUDCA. The effect of TUDCA on the Aldo-infused inflammatory response and renal injury was investigated using periodic acid-Schiff staining, real-time PCR, Western blot, and ELISA. We demonstrate that Aldo leads to impaired renal function and inhibition of ER stress via TUDCA attenuates renal fibrosis. This was indicated by decreased collagen I, collagen IV, fibronectin, and TGF-β expression, as well as the downregulation of the expression of Nlrp3 inflammasome markers, Nlrp3, ASC, IL-1β, and IL-18. This paper presents an important role for ER stress on the renal inflammatory response to Aldo. Additionally, the inhibition of ER stress by TUDCA negatively regulates the levels of these inflammatory molecules in the context of Aldo.

DKK1 mediated inhibition of Wnt signaling in postnatal mice leads to loss of TEC progenitors and thymic degeneration.

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Masako Osada

2010-02-01

Full Text Available Thymic epithelial cell (TEC microenvironments are essential for the recruitment of T cell precursors from the bone marrow, as well as the subsequent expansion and selection of thymocytes resulting in a mature self-tolerant T cell repertoire. The molecular mechanisms, which control both the initial development and subsequent maintenance of these critical microenvironments, are poorly defined. Wnt signaling has been shown to be important to the development of several epithelial tissues and organs. Regulation of Wnt signaling has also been shown to impact both early thymocyte and thymic epithelial development. However, early blocks in thymic organogenesis or death of the mice have prevented analysis of a role of canonical Wnt signaling in the maintenance of TECs in the postnatal thymus.Here we demonstrate that tetracycline-regulated expression of the canonical Wnt inhibitor DKK1 in TECs localized in both the cortex and medulla of adult mice, results in rapid thymic degeneration characterized by a loss of DeltaNP63(+ Foxn1(+ and Aire(+ TECs, loss of K5K8DP TECs thought to represent or contain an immature TEC progenitor, decreased TEC proliferation and the development of cystic structures, similar to an aged thymus. Removal of DKK1 from DKK1-involuted mice results in full recovery, suggesting that canonical Wnt signaling is required for the differentiation or proliferation of TEC populations needed for maintenance of properly organized adult thymic epithelial microenvironments.Taken together, the results of this study demonstrate that canonical Wnt signaling within TECs is required for the maintenance of epithelial microenvironments in the postnatal thymus, possibly through effects on TEC progenitor/stem cell populations. Downstream targets of Wnt signaling, which are responsible for maintenance of these TEC progenitors may provide useful targets for therapies aimed at counteracting age associated thymic involution or the premature thymic

D-Saccharic acid 1,4-lactone protects diabetic rat kidney by ameliorating hyperglycemia-mediated oxidative stress and renal inflammatory cytokines via NF-κB and PKC signaling

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Bhattacharya, Semantee [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Manna, Prasenjit [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India); Gachhui, Ratan [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Sil, Parames C., E-mail: parames@bosemain.boseinst.ac.in [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India)

2013-02-15

Increasing evidence suggests that oxidative stress is involved in the pathogenesis of diabetic nephropathy (DN) and this can be attenuated by antioxidants. D-Saccharic acid 1,4-lactone (DSL) is known for its detoxifying and antioxidant properties. Our early investigation showed that DSL can ameliorate alloxan (ALX) induced diabetes mellitus and oxidative stress in rats by inhibiting pancreatic β-cell apoptosis. In the present study we, therefore, investigated the protective role of DSL against renal injury in ALX induced diabetic rats. ALX exposure (at a dose of 120 mg/kg body weight, i. p., once) elevated the blood glucose level, serum markers related to renal injury, the production of reactive oxygen species (ROS), and disturbed the intra-cellular antioxidant machineries. Oral administration of DSL (80 mg/kg body weight) restored all these alterations close to normal. In addition, DSL could also normalize the aldose reductase activity which was found to increase in the diabetic rats. Investigating the mechanism of its protective activity, we observed the activation of different isoforms of PKC along with the accumulation of matrix proteins like collagen and fibronectin. The diabetic rats also showed nuclear translocation of NF-κB and increase in the concentration of inflammatory cytokines in the renal tissue. The activation of mitochondria dependent apoptotic pathway was observed in the diabetic rat kidneys. However, treatment of diabetic rats with DSL counteracted all these changes. These findings, for the first time, demonstrated that DSL could ameliorate renal dysfunction in diabetic rats by suppressing the oxidative stress related signalling pathways. - Highlights: ► Sustained hyperglycemia and oxidative stress lead to diabetic renal injury. ► D-saccharic acid 1,4-lactone prevents renal damage in alloxan-induced diabetes. ► It restores intra-cellular antioxidant machineries and kidney apoptosis. ► DSL reduces hyperglycemia-mediated oxidative stress

Stem cell factor expression after renal ischemia promotes tubular epithelial survival.

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Geurt Stokman

Full Text Available BACKGROUND: Renal ischemia leads to apoptosis of tubular epithelial cells and results in decreased renal function. Tissue repair involves re-epithelialization of the tubular basement membrane. Survival of the tubular epithelium following ischemia is therefore important in the successful regeneration of renal tissue. The cytokine stem cell factor (SCF has been shown to protect the tubular epithelium against apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: In a mouse model for renal ischemia/reperfusion injury, we studied how expression of c-KIT on tubular epithelium and its ligand SCF protect cells against apoptosis. Administration of SCF specific antisense oligonucleotides significantly decreased specific staining of SCF following ischemia. Reduced SCF expression resulted in impaired renal function, increased tubular damage and increased tubular epithelial apoptosis, independent of inflammation. In an in vitro hypoxia model, stimulation of tubular epithelial cells with SCF activated survival signaling and decreased apoptosis. CONCLUSIONS/SIGNIFICANCE: Our data indicate an important role for c-KIT and SCF in mediating tubular epithelial cell survival via an autocrine pathway.

LINKING TYPE Ia SUPERNOVA PROGENITORS AND THEIR RESULTING EXPLOSIONS

International Nuclear Information System (INIS)

Foley, Ryan J.; Kirshner, Robert P.; Simon, Joshua D.; Burns, Christopher R.; Gal-Yam, Avishay; Hamuy, Mario; Morrell, Nidia I.; Phillips, Mark M.; Shields, Gregory A.; Sternberg, Assaf

2012-01-01

Comparing the ejecta velocities at maximum brightness and narrow circumstellar/interstellar Na D absorption line profiles of a sample of 23 Type Ia supernovae (SNe Ia), we determine that the properties of SN Ia progenitor systems and explosions are intimately connected. As demonstrated by Sternberg et al., half of all SNe Ia with detectable Na D absorption at the host-galaxy redshift in high-resolution spectroscopy have Na D line profiles with significant blueshifted absorption relative to the strongest absorption component, which indicates that a large fraction of SN Ia progenitor systems have strong outflows. In this study, we find that SNe Ia with blueshifted circumstellar/interstellar absorption systematically have higher ejecta velocities and redder colors at maximum brightness relative to the rest of the SN Ia population. This result is robust at a 98.9%-99.8% confidence level, providing the first link between the progenitor systems and properties of the explosion. This finding is further evidence that the outflow scenario is the correct interpretation of the blueshifted Na D absorption, adding additional confirmation that some SNe Ia are produced from a single-degenerate progenitor channel. An additional implication is that either SN Ia progenitor systems have highly asymmetric outflows that are also aligned with the SN explosion or SNe Ia come from a variety of progenitor systems where SNe Ia from systems with strong outflows tend to have more kinetic energy per unit mass than those from systems with weak or no outflows.

Haemopoietic progenitor cells in human peripheral blood

International Nuclear Information System (INIS)

Zwaan, F.E.

1980-01-01

The purpose of the investigation reported is to purify haemopoietic progenitor cells from human peripheral blood using density gradient centrifugation in order to isolate a progenitor cell fraction without immunocompetent cells. The purification technique of peripheral blood flow colony forming unit culture (CFU-c) by means of density gradient centrifugation and a combined depletion of various rosettes is described. The results of several 'in vitro' characteristics of purified CFU-c suspensions and of the plasma clot diffusion chamber culture technique are presented. Irradiation studies revealed that for both human bone marrow and peripheral blood the CFU-c were less radioresistant than clusters. Elimination of monocytes (and granulocytes) from the test suspensions induced an alteration in radiosensitivity pararmeters. The results obtained with the different techniques are described by analysing peripheral progenitor cell activity in myeloproliferative disorders. (Auth.)

Constraints on the Progenitor System of SN 2016gkg from a Comprehensive Statistical Analysis

Science.gov (United States)

Sravan, Niharika; Marchant, Pablo; Kalogera, Vassiliki; Margutti, Raffaella

2018-01-01

Type IIb supernovae (SNe) present a unique opportunity for understanding the progenitors of stripped-envelope SNe because the stellar progenitor of several SNe IIb have been identified in pre-explosion images. In this paper, we use Bayesian inference and a large grid of non-rotating solar-metallicity single and binary stellar models to derive the associated probability distributions of single and binary progenitors of the SN IIb 2016gkg using existing observational constraints. We find that potential binary star progenitors have smaller pre-SN hydrogen-envelope and helium-core masses than potential single-star progenitors typically by 0.1 M ⊙ and 2 M ⊙, respectively. We find that, a binary companion, if present, is a main-sequence or red-giant star. Apart from this, we do not find strong constraints on the nature of the companion star. We demonstrate that the range of progenitor helium-core mass inferred from observations could help improve constraints on the progenitor. We find that the probability that the progenitor of SN 2016gkg was a binary is 22% when we use constraints only on the progenitor luminosity and effective temperature. Imposing the range of pre-SN progenitor hydrogen-envelope mass and radius inferred from SN light curves, the probability that the progenitor is a binary increases to 44%. However, there is no clear preference for a binary progenitor. This is in contrast to binaries being the currently favored formation channel for SNe IIb. Our analysis demonstrates the importance of statistical inference methods to constrain progenitor channels.

Neuronal Progenitor Maintenance Requires Lactate Metabolism and PEPCK-M-Directed Cataplerosis.

Science.gov (United States)

Álvarez, Zaida; Hyroššová, Petra; Perales, José Carlos; Alcántara, Soledad

2016-03-01

This study investigated the metabolic requirements for neuronal progenitor maintenance in vitro and in vivo by examining the metabolic adaptations that support neuronal progenitors and neural stem cells (NSCs) in their undifferentiated state. We demonstrate that neuronal progenitors are strictly dependent on lactate metabolism, while glucose induces their neuronal differentiation. Lactate signaling is not by itself capable of maintaining the progenitor phenotype. The consequences of lactate metabolism include increased mitochondrial and oxidative metabolism, with a strict reliance on cataplerosis through the mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M) pathway to support anabolic functions, such as the production of extracellular matrix. In vivo, lactate maintains/induces populations of postnatal neuronal progenitors/NSCs in a PEPCK-M-dependent manner. Taken together, our data demonstrate that, lactate alone or together with other physical/biochemical cues maintain NSCs/progenitors with a metabolic signature that is classically found in tissues with high anabolic capacity. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

α-Ketoglutarate Promotes Pancreatic Progenitor-Like Cell Proliferation

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Jing Song

2018-03-01

Full Text Available A major source of β cell generation is pancreatic progenitor-like cell differentiation. Multiple studies have confirmed that stem cell metabolism plays important roles in self-renewal and proliferation. In the absence of glucose, glutamine provides the energy for cell division and growth. Furthermore, α-ketoglutarate (αKG, a precursor for glutamine synthesis, is sufficient for enabling glutamine-independent cell proliferation. We have demonstrated that αKG contributes to the large-scale proliferation of pancreatic progenitor-like cells that can provide an ample amount of clinically relevant β cells. We compared the mRNA expression of a subset of genes, the abundance of ATP, reactive oxide species, mitochondrial number, and the colony-forming frequency between mouse pancreatic CD133+ and CD133− cells. We employed Real-Time PCR, immunostaining and passage assays to investigate self-renewal and proliferation of pancreatic progenitor-like cells in a 3D culture system in the presence and absence of αKG. The energy metabolism of CD133+ cells was more prone to oxidative phosphorylation. However, in the 3D culture system, when αKG was supplemented to the culture medium, the proliferation of the pancreatic progenitor-like cells was significantly elevated. We confirmed that the presence of αKG correlated with the up-regulation of Ten-Eleven Translocation (Tet. αKG can promote the proliferation of pancreatic progenitor-like cells via the up-regulation of Tet.

α-Ketoglutarate Promotes Pancreatic Progenitor-Like Cell Proliferation.

Science.gov (United States)

Song, Jing; Ma, Dongshen; Xing, Yun; Tang, Shanshan; Alahdal, Murad; Guo, Jiamin; Pan, Yi; Zhang, Yanfeng; Shen, Yumeng; Wu, Qiong; Lu, Zhou; Jin, Liang

2018-03-22

A major source of β cell generation is pancreatic progenitor-like cell differentiation. Multiple studies have confirmed that stem cell metabolism plays important roles in self-renewal and proliferation. In the absence of glucose, glutamine provides the energy for cell division and growth. Furthermore, α-ketoglutarate (αKG), a precursor for glutamine synthesis, is sufficient for enabling glutamine-independent cell proliferation. We have demonstrated that αKG contributes to the large-scale proliferation of pancreatic progenitor-like cells that can provide an ample amount of clinically relevant β cells. We compared the mRNA expression of a subset of genes, the abundance of ATP, reactive oxide species, mitochondrial number, and the colony-forming frequency between mouse pancreatic CD133⁺ and CD133 - cells. We employed Real-Time PCR, immunostaining and passage assays to investigate self-renewal and proliferation of pancreatic progenitor-like cells in a 3D culture system in the presence and absence of αKG. The energy metabolism of CD133⁺ cells was more prone to oxidative phosphorylation. However, in the 3D culture system, when αKG was supplemented to the culture medium, the proliferation of the pancreatic progenitor-like cells was significantly elevated. We confirmed that the presence of αKG correlated with the up-regulation of Ten-Eleven Translocation (Tet). αKG can promote the proliferation of pancreatic progenitor-like cells via the up-regulation of Tet.

Activated Fps/Fes partially rescues the in vivo developmental potential of Flk1-deficient vascular progenitor cells.

Science.gov (United States)

Haigh, Jody J; Ema, Masatsugu; Haigh, Katharina; Gertsenstein, Marina; Greer, Peter; Rossant, Janet; Nagy, Andras; Wagner, Erwin F

2004-02-01

Relatively little is known about the modulators of the vascular endothelial growth factor A (VEGF-A)/Flk1 signaling cascade. To functionally characterize this pathway, VEGF-A stimulation of endothelial cells was performed. VEGF-A-mediated Flk1 activation resulted in increased translocation of the endogenous Fps/Fes cytoplasmic tyrosine kinase to the plasma membrane and increased tyrosine phosphorylation, suggesting a role for Fps/Fes in VEGF-A/Flk1 signaling events. Addition of a myristoylation consensus sequence to Fps/Fes resulted in VEGF-A-independent membrane localization of Fps/Fes in endothelial cells. Expression of the activated Fps/Fes protein in Flk1-deficient embryonic stem (ES) cells rescued their contribution to the developing vascular endothelium in vivo by using ES cell-derived chimeras. Activated Fps/Fes contributed to this rescue event by restoring the migratory potential to Flk1 null progenitors, which is required for movement of hemangioblasts from the primitive streak region into the yolk sac proper. Activated Fps/Fes in the presence of Flk1 increased the number of hemangioblast colonies in vitro and increased the number of mesodermal progenitors in vivo. These results suggest that Fps/Fes may act synergistically with Flk1 to modulate hemangioblast differentiation into the endothelium. We have also demonstrated that activated Fps/Fes causes hemangioma formation in vivo, independently of Flk1, as a result of increasing vascular progenitor density.

Development and molecular composition of the hepatic progenitor cell niche.

Science.gov (United States)

Vestentoft, Peter Siig

2013-05-01

End-stage liver diseases represent major health problems that are currently treated by liver transplantation. However, given the world-wide shortage of donor livers novel strategies are needed for therapeutic treatment. Adult stem cells have the ability to self-renew and differentiate into the more specialized cell types of a given organ and are found in tissues throughout the body. These cells, whose progeny are termed progenitor cells in human liver and oval cells in rodents, have the potential to treat patients through the generation of hepatic parenchymal cells, even from the patient's own tissue. Little is known regarding the nature of the hepatic progenitor cells. Though they are suggested to reside in the most distal part of the biliary tree, the canal of Hering, the lack of unique surface markers for these cells has hindered their isolation and characterization. Upon activation, they proliferate and form ductular structures, termed "ductular reactions", which radiate into the hepatic parenchyma. The ductular reactions contain activated progenitor cells that not only acquire a phenotype resembling that observed in developing liver but also display markers of differentiation shared with the cholangiocytic or hepatocytic lineages, the two parenchymal hepatic cell types. Interactions between the putative progenitor cells, the surrounding support cells and the extracellular matrix scaffold, all constituting the progenitor cell niche, are likely to be important for regulating progenitor cell activity and differentiation. Therefore, identifying novel progenitor cell markers and deciphering their microenvironment could facilitate clinical use. The aims of the present PhD thesis were to expand knowledge of the hepatic progenitor cell niche and characterize it both during development and in disease. Several animal models of hepatic injury are known to induce activation of the progenitor cells. In order to identify possible progenitor cell markers and niche components

Requirement of myomaker-mediated stem cell fusion for skeletal muscle hypertrophy.

Science.gov (United States)

Goh, Qingnian; Millay, Douglas P

2017-02-10

Fusion of skeletal muscle stem/progenitor cells is required for proper development and regeneration, however the significance of this process during adult muscle hypertrophy has not been explored. In response to muscle overload after synergist ablation in mice, we show that myomaker, a muscle specific membrane protein essential for myoblast fusion, is activated mainly in muscle progenitors and not myofibers. We rendered muscle progenitors fusion-incompetent through genetic deletion of myomaker in muscle stem cells and observed a complete reduction of overload-induced hypertrophy. This blunted hypertrophic response was associated with a reduction in Akt and p70s6k signaling and protein synthesis, suggesting a link between myonuclear accretion and activation of pro-hypertrophic pathways. Furthermore, fusion-incompetent muscle exhibited increased fibrosis after muscle overload, indicating a protective role for normal stem cell activity in reducing myofiber strain associated with hypertrophy. These findings reveal an essential contribution of myomaker-mediated stem cell fusion during physiological adult muscle hypertrophy.

NFIX Regulates Neural Progenitor Cell Differentiation During Hippocampal Morphogenesis

Science.gov (United States)

Heng, Yee Hsieh Evelyn; McLeay, Robert C.; Harvey, Tracey J.; Smith, Aaron G.; Barry, Guy; Cato, Kathleen; Plachez, Céline; Little, Erica; Mason, Sharon; Dixon, Chantelle; Gronostajski, Richard M.; Bailey, Timothy L.; Richards, Linda J.; Piper, Michael

2014-01-01

Neural progenitor cells have the ability to give rise to neurons and glia in the embryonic, postnatal and adult brain. During development, the program regulating whether these cells divide and self-renew or exit the cell cycle and differentiate is tightly controlled, and imbalances to the normal trajectory of this process can lead to severe functional consequences. However, our understanding of the molecular regulation of these fundamental events remains limited. Moreover, processes underpinning development of the postnatal neurogenic niches within the cortex remain poorly defined. Here, we demonstrate that Nuclear factor one X (NFIX) is expressed by neural progenitor cells within the embryonic hippocampus, and that progenitor cell differentiation is delayed within Nfix−/− mice. Moreover, we reveal that the morphology of the dentate gyrus in postnatal Nfix−/− mice is abnormal, with fewer subgranular zone neural progenitor cells being generated in the absence of this transcription factor. Mechanistically, we demonstrate that the progenitor cell maintenance factor Sry-related HMG box 9 (SOX9) is upregulated in the hippocampus of Nfix−/− mice and demonstrate that NFIX can repress Sox9 promoter-driven transcription. Collectively, our findings demonstrate that NFIX plays a central role in hippocampal morphogenesis, regulating the formation of neuronal and glial populations within this structure. PMID:23042739

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

Energy Technology Data Exchange (ETDEWEB)

Hosokawa, S; Daijo, K; Okabe, T; Kawamura, J; Hara, A [Kyoto Univ. (Japan). Hospital

1979-08-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1.

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

International Nuclear Information System (INIS)

Hosokawa, Shin-ichi; Daijo, Kazuyuki; Okabe, Tatsushiro; Kawamura, Juichi; Hara, Akira

1979-01-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1. (author)

DISAPPEARANCE OF THE PROGENITOR OF SUPERNOVA iPTF13bvn

Energy Technology Data Exchange (ETDEWEB)

Folatelli, Gastón; Bersten, Melina C. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Instituto de Astrofísica de La Plata (IALP), CONICET, Paseo del Bosque S/N, B1900FWA La Plata (Argentina); Van Dyk, Schuyler D. [IPAC/Caltech, Mailcode 100-22, Pasadena, CA 91125 (United States); Kuncarayakti, Hanindyo; Pignata, Giuliano; Hamuy, Mario [Millennium Institute of Astrophysics (MAS), Santiago (Chile); Maeda, Keiichi; Nomoto, Ken’ichi; Quimby, Robert M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Zheng, WeiKang; Filippenko, Alexei V.; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Smith, Nathan [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Elias-Rosa, Nancy [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States); Miller, Adam A., E-mail: gaston.folatelli@ipmu.jp [Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States)

2016-07-10

Supernova (SN) iPTF13bvn in NGC 5806 was the first Type Ib SN to have been tentatively associated with a progenitor in pre-explosion images. We performed deep ultraviolet (UV) and optical Hubble Space Telescope observations of the SN site ∼740 days after explosion. We detect an object in the optical bands that is fainter than the pre-explosion object. This dimming is likely not produced by dust absorption in the ejecta; thus, our finding confirms the connection of the progenitor candidate with the SN. The object in our data is likely dominated by the fading SN, implying that the pre-SN flux is mostly due to the progenitor. We compare our revised pre-SN photometry with previously proposed models. Although binary progenitors are favored, models need to be refined. In particular, to comply with our deep UV detection limit, any companion star must be less luminous than a late-O star or substantially obscured by newly formed dust. A definitive progenitor characterization will require further observations to disentangle the contribution of a much fainter SN and its environment.

Characterization of Hemagglutinin Negative Botulinum Progenitor Toxins

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Suzanne R. Kalb

2017-06-01

Full Text Available Botulism is a disease involving intoxication with botulinum neurotoxins (BoNTs, toxic proteins produced by Clostridium botulinum and other clostridia. The 150 kDa neurotoxin is produced in conjunction with other proteins to form the botulinum progenitor toxin complex (PTC, alternating in size from 300 kDa to 500 kDa. These progenitor complexes can be classified into hemagglutinin positive or hemagglutinin negative, depending on the ability of some of the neurotoxin-associated proteins (NAPs to cause hemagglutination. The hemagglutinin positive progenitor toxin complex consists of BoNT, nontoxic non-hemagglutinin (NTNH, and three hemagglutinin proteins; HA-70, HA-33, and HA-17. Hemagglutinin negative progenitor toxin complexes contain BoNT and NTNH as the minimally functional PTC (M-PTC, but not the three hemagglutinin proteins. Interestingly, the genome of hemagglutinin negative progenitor toxin complexes comprises open reading frames (orfs which encode for three proteins, but the existence of these proteins has not yet been extensively demonstrated. In this work, we demonstrate that these three proteins exist and form part of the PTC for hemagglutinin negative complexes. Several hemagglutinin negative strains producing BoNT/A, /E, and /F were found to contain the three open reading frame proteins. Additionally, several BoNT/A-containing bivalent strains were examined, and NAPs from both genes, including the open reading frame proteins, were associated with BoNT/A. The open reading frame encoded proteins are more easily removed from the botulinum complex than the hemagglutinin proteins, but are present in several BoNT/A and /F toxin preparations. These are not easily removed from the BoNT/E complex, however, and are present even in commercially-available purified BoNT/E complex.

Characterization of Proliferating Neural Progenitors after Spinal Cord Injury in Adult Zebrafish.

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Subhra Prakash Hui

Full Text Available Zebrafish can repair their injured brain and spinal cord after injury unlike adult mammalian central nervous system. Any injury to zebrafish spinal cord would lead to increased proliferation and neurogenesis. There are presences of proliferating progenitors from which both neuronal and glial loss can be reversed by appropriately generating new neurons and glia. We have demonstrated the presence of multiple progenitors, which are different types of proliferating populations like Sox2+ neural progenitor, A2B5+ astrocyte/ glial progenitor, NG2+ oligodendrocyte progenitor, radial glia and Schwann cell like progenitor. We analyzed the expression levels of two common markers of dedifferentiation like msx-b and vimentin during regeneration along with some of the pluripotency associated factors to explore the possible role of these two processes. Among the several key factors related to pluripotency, pou5f1 and sox2 are upregulated during regeneration and associated with activation of neural progenitor cells. Uncovering the molecular mechanism for endogenous regeneration of adult zebrafish spinal cord would give us more clues on important targets for future therapeutic approach in mammalian spinal cord repair and regeneration.

Uncovering the Number and Clonal Dynamics of Mesp1 Progenitors during Heart Morphogenesis

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Samira Chabab

2016-01-01

Full Text Available The heart arises from distinct sources of cardiac progenitors that independently express Mesp1 during gastrulation. The precise number of Mesp1 progenitors that are specified during the early stage of gastrulation, and their clonal behavior during heart morphogenesis, is currently unknown. Here, we used clonal and mosaic tracing of Mesp1-expressing cells combined with quantitative biophysical analysis of the clonal data to define the number of cardiac progenitors and their mode of growth during heart development. Our data indicate that the myocardial layer of the heart derive from ∼250 Mesp1-expressing cardiac progenitors born during gastrulation. Despite arising at different time points and contributing to different heart regions, the temporally distinct cardiac progenitors present very similar clonal dynamics. These results provide insights into the number of cardiac progenitors and their mode of growth and open up avenues to decipher the clonal dynamics of progenitors in other organs and tissues.

Intracellular Kinases Mediate Increased Translation and Secretion of Netrin-1 from Renal Tubular Epithelial Cells

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Jayakumar, Calpurnia; Mohamed, Riyaz; Ranganathan, Punithavathi Vilapakkam; Ramesh, Ganesan

2011-01-01

Background Netrin-1 is a laminin-related secreted protein, is highly induced after tissue injury, and may serve as a marker of injury. However, the regulation of netrin-1 production is not unknown. Current study was carried out in mouse and mouse kidney cell line (TKPTS) to determine the signaling pathways that regulate netrin-1 production in response to injury. Methods and Principal Findings Ischemia reperfusion injury of the kidney was induced in mice by clamping renal pedicle for 30 minutes. Cellular stress was induced in mouse proximal tubular epithelial cell line by treating with pervanadate, cisplatin, lipopolysaccharide, glucose or hypoxia followed by reoxygenation. Netrin-1 expression was quantified by real time RT-PCR and protein production was quantified using an ELISA kit. Cellular stress induced a large increase in netrin-1 production without increase in transcription of netrin-1 gene. Mitogen activated protein kinase, ERK mediates the drug induced netrin-1 mRNA translation increase without altering mRNA stability. Conclusion Our results suggest that netrin-1 expression is suppressed at the translational level and MAPK activation leads to rapid translation of netrin-1 mRNA in the kidney tubular epithelial cells. PMID:22046354

Intracellular kinases mediate increased translation and secretion of netrin-1 from renal tubular epithelial cells.

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Calpurnia Jayakumar

Full Text Available BACKGROUND: Netrin-1 is a laminin-related secreted protein, is highly induced after tissue injury, and may serve as a marker of injury. However, the regulation of netrin-1 production is not unknown. Current study was carried out in mouse and mouse kidney cell line (TKPTS to determine the signaling pathways that regulate netrin-1 production in response to injury. METHODS AND PRINCIPAL FINDINGS: Ischemia reperfusion injury of the kidney was induced in mice by clamping renal pedicle for 30 minutes. Cellular stress was induced in mouse proximal tubular epithelial cell line by treating with pervanadate, cisplatin, lipopolysaccharide, glucose or hypoxia followed by reoxygenation. Netrin-1 expression was quantified by real time RT-PCR and protein production was quantified using an ELISA kit. Cellular stress induced a large increase in netrin-1 production without increase in transcription of netrin-1 gene. Mitogen activated protein kinase, ERK mediates the drug induced netrin-1 mRNA translation increase without altering mRNA stability. CONCLUSION: Our results suggest that netrin-1 expression is suppressed at the translational level and MAPK activation leads to rapid translation of netrin-1 mRNA in the kidney tubular epithelial cells.

Inter-progenitor pool wiring: An evolutionarily conserved strategy that expands neural circuit diversity.

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Suzuki, Takumi; Sato, Makoto

2017-11-15

Diversification of neuronal types is key to establishing functional variations in neural circuits. The first critical step to generate neuronal diversity is to organize the compartmental domains of developing brains into spatially distinct neural progenitor pools. Neural progenitors in each pool then generate a unique set of diverse neurons through specific spatiotemporal specification processes. In this review article, we focus on an additional mechanism, 'inter-progenitor pool wiring', that further expands the diversity of neural circuits. After diverse types of neurons are generated in one progenitor pool, a fraction of these neurons start migrating toward a remote brain region containing neurons that originate from another progenitor pool. Finally, neurons of different origins are intermingled and eventually form complex but precise neural circuits. The developing cerebral cortex of mammalian brains is one of the best examples of inter-progenitor pool wiring. However, Drosophila visual system development has revealed similar mechanisms in invertebrate brains, suggesting that inter-progenitor pool wiring is an evolutionarily conserved strategy that expands neural circuit diversity. Here, we will discuss how inter-progenitor pool wiring is accomplished in mammalian and fly brain systems. Copyright © 2017 Elsevier Inc. All rights reserved.

Prolonged Mitosis of Neural Progenitors Alters Cell Fate in the Developing Brain.

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Pilaz, Louis-Jan; McMahon, John J; Miller, Emily E; Lennox, Ashley L; Suzuki, Aussie; Salmon, Edward; Silver, Debra L

2016-01-06

Embryonic neocortical development depends on balanced production of progenitors and neurons. Genetic mutations disrupting progenitor mitosis frequently impair neurogenesis; however, the link between altered mitosis and cell fate remains poorly understood. Here we demonstrate that prolonged mitosis of radial glial progenitors directly alters neuronal fate specification and progeny viability. Live imaging of progenitors from a neurogenesis mutant, Magoh(+/-), reveals that mitotic delay significantly correlates with preferential production of neurons instead of progenitors, as well as apoptotic progeny. Independently, two pharmacological approaches reveal a causal relationship between mitotic delay and progeny fate. As mitotic duration increases, progenitors produce substantially more apoptotic progeny or neurons. We show that apoptosis, but not differentiation, is p53 dependent, demonstrating that these are distinct outcomes of mitotic delay. Together our findings reveal that prolonged mitosis is sufficient to alter fates of radial glia progeny and define a new paradigm to understand how mitosis perturbations underlie brain size disorders such as microcephaly. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of pressure in angiotensin II-induced renal injury: chronic servo-control of renal perfusion pressure in rats.

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Mori, Takefumi; Cowley, Allen W

2004-04-01

Renal perfusion pressure was servo-controlled chronically in rats to quantify the relative contribution of elevated arterial pressure versus angiotensin II (Ang II) on the induction of renal injury in Ang II-induced hypertension. Sprague-Dawley rats fed a 4% salt diet were administered Ang II for 14 days (25 ng/kg per minute IV; saline only for sham rats), and the renal perfusion pressure to the left kidney was continuously servo-controlled to maintain a normal pressure in that kidney throughout the period of hypertension. An aortic occluder was implanted around the aorta between the two renal arteries and carotid and femoral arterial pressure were measured continuously throughout the experiment to determine uncontrolled and controlled renal perfusion pressure, respectively. Renal perfusion pressure of uncontrolled, controlled, and sham kidneys over the period of Ang II or saline infusion averaged 152.6+/-7.0, 117.4+/-3.5, and 110.7+/-2.2 mm Hg, respectively. The high-pressure uncontrolled kidneys exhibited tubular necrosis and interstitial fibrosis, especially prominent in the outer medullary region. Regional glomerular sclerosis and interlobular artery injury were also pronounced. Controlled kidneys were significantly protected from interlobular artery injury, juxtamedullary glomeruli injury, tubular necrosis, and interstitial fibrosis as determined by comparing the level of injury. Glomerular injury was not prevented in the outer cortex. Transforming growth factor (TGF)-beta and active NF-kappaB proteins determined by immunohistochemistry were colocalized in the uncontrolled kidney in regions of interstitial fibrosis. We conclude that the preferential juxtamedullary injury found in Ang II hypertension is largely induced by pressure and is probably mediated through the TGF-beta and NF-kappaB pathway.

A new process for fabricating nanodot arrays on selective regions with diblock copolymer thin film

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Park, Dae-Ho [Department of Materials Science and Engineering, Polymer Research Institute, Pohang University of Science and Technology, San 31, Hyoja-Dong, Nam-Gu, Pohang 790-784 (Korea, Republic of)

2007-09-12

A procedure for micropatterning a single layer of nanodot arrays in selective regions is demonstrated by using thin films of polystyrene-b-poly(t-butyl acrylate) (PS-b-PtBA) diblock copolymer. The thin-film self-assembled into hexagonally arranged PtBA nanodomains in a PS matrix on a substrate by solvent annealing with 1,4-dioxane. The PtBA nanodomains were converted into poly(acrylic acid) (PAA) having carboxylic-acid-functionalized nanodomains by exposure to hydrochloric acid vapor, or were removed by ultraviolet (UV) irradiation to generate vacant sites without any functional groups due to the elimination of PtBA domains. By sequential treatment with aqueous sodium bicarbonate and aqueous zinc acetate solution, zinc cations were selectively loaded only on the carboxylic-acid-functionalized nanodomains prepared via hydrolysis. Macroscopic patterning through a photomask via UV irradiation, hydrolysis, sequential zinc cation loading and calcination left a nanodot array of zinc oxide on a selectively UV-shaded region.

Renal computed angiography. Part I: Renal CT phlebography. Renal veins variants

International Nuclear Information System (INIS)

Al-Amin, M.; Krupev, M.; Hadjidekov, V.; Plachkov, I.

2012-01-01

The changing trend in renal surgery, transplantation and minimal invasive urology implies preprocedure evaluation of renal veins. Development of imaging methods offers new possibilities for venographic visualization. The goal of this study is to present authors experience in visualization of renal veins using 64 MDCT and to evaluate the utility in assessments of their variants. 128 patients (68 females and 60 males, mean age 53,3) with urological complaints underwent 64MDCT examination including CT angiography. Contrast enhancement includes 3-4ml/sec injection flow of 90 ml contrast medium followed by 20 ml saline at the same rate. In 23 out of 128 examined patients some of the common variants of the renal vein is found. 64 MDCT angiography visualize very well renal veins and becomes method of choice in preoperative assessment of renal vein anatomy. (authors)

Not all renal stem cell niches are the same: anatomy of an evolution

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Clara Gerosa

2016-08-01

Full Text Available The renal stem cell niche represents the most important structure of the developing kidney, responsible for nephrogenesis. Recently, some Authors have reported, at ultrastructural level, a previously unknown complexity of the architecture of renal stem cell niche in experimental models. This study was aimed at studying, at histological level, the anatomy of renal stem cell niches in the human fetal kidney. To this end, ten fetal kidneys, whose gestational ages ranged from 11 up to 24 weeks, were studied. H&E-stained sections were observed at high power. The study of the anatomy of renal stem cell niches in the human kidney revealed a previously unreported complexity: some niches appeared as a roundish arrangement of mesenchymal cells; others showed the initial phases of induction by ureteric buds; in other niches the process of mesenchymal epithelial transition was more evident; finally, in other stem cell niches the first signs of nephron origin were detectable. These findings suggest the existence of niches with different anatomy in the same kidney, indicating different stages of evolution even in adjacent niches. All stem cell niches were in strict contact with the capsular cells, suggesting a major role of the renal capsule in nephrogenesis. Finally, our study confirms the existence of a strict contact between the bud tip cells and the surrounding mesenchyme in the human developing kidney, giving a morphological support to the theory of intercellular channels allowing the passage of transcription factors from the epithelial to the mesenchymal stem/progenitors cells.Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

Immune-mediated bone marrow failure syndromes of progenitor and stem cells: molecular analysis of cytotoxic T cell clones.

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Ramon Tiu

2007-03-01

Full Text Available The unique structure of the T cell receptor (TCR enables molecular identification of individual T cell clones and provides an unique opportunity for the design of molecular diagnostic tests based on the structure of the rearranged TCR chain e.g., using the TCR CDR3 region. Initially, clonal T cell malignancies, including T cell large granular lymphocyte leukemia (T-LGL, mucosis fungoides and peripheral T cell lymphoma were targets for the TCR-based analytic assays such as detection of clonality by T-gamma rearrangement using y-chain-specific PCR or Southern Blotting. Study of these disorders facilitated further analytic concepts and application of rational methods of TCR analysis to investigations of polyclonal T cell-mediated diseases. In hematology, such conditions include graft versus host disease (GvHD and immune-mediated bone marrow failure syndromes. In aplastic anemia (AA, myelodysplastic syndrome (MDS or paroxysmal nocturnal hemoglobinuria (PNH, cytotoxic T cell responses may be directed against certain antigens located on stem or more lineage-restricted progenitor cells in single lineage cytopenias. The nature of the antigenic targets driving polyclonal CTL responses remains unclear. Novel methods of TCR repertoire analysis, include VB flow cytometry, peptide-specific tetramer staining, in vitro stimulation assays and TCR CDR3-specific PCR. Such PCR assay can be either VB family-specific or multiplexed for all VB families. Amplified products can be characterized and quantitated to facilitate detection of the most immunodominant clonotypes. Such clonotypes may serve as markers for the global polyclonal T cell response. Identification of these clonotypes can be performed in blood and tissue biopsy material by various methods. Once immunodominant clonotypes corresponding to pathogenic CTL clones are identified they can serve as surrogate markers for the activity of the pathophysiologic process or even indicate the presence of specific

Low functional programming of renal AT2R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure

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Ao, Ying; Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na; Li, Bin; Yang, Shuailong; Xia, Liping; Wu, Yong; Wang, Linlong; He, Zheng; Wang, Hui

2015-01-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT 2 R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT 1a R)/AT 2 R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT 2 R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT 2 R might mediate the developmental origin of adult glomerulosclerosis. - Highlights: • Prenatal caffeine exposure induces glomerulosclerosis in adult offspring. • Prenatal caffeine exposure inhibits

Calpastatin overexpression prevents progression of S-1,2-dichlorovinyl-L-cysteine (DCVC)-initiated acute renal injury and renal failure (ARF) in diabetes

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Dnyanmote, Ankur V.; Sawant, Sharmilee P.; Lock, Edward A.; Latendresse, John R.; Warbritton, Alan A.; Mehendale, Harihara M.

2006-01-01

Previously we have shown that 90% of streptozotocin (STZ)-induced type-1 diabetic (DB) mice survive from acute renal failure (ARF) and death induced by a normally LD 9 dose (75 mg/kg, i.p.) of the nephrotoxicant S-1,2-dichlorovinyl-L-cysteine (DCVC). This remarkable protection is due to a combination of slower progression of DCVC-initiated renal injury and increased compensatory nephrogenic tissue repair in the DB kidneys. BRDU immunohistochemistry revealed that the DB condition led to 4-fold higher number of proximal tubular cells (PTC) entering S-phase of cell cycle. In the present study, we tested the hypothesis that DB-induced augmentation of PTC into S-phase is accompanied by overexpression of the calpain-inhibitor calpastatin, which endogenously prevents the progression of DCVC-initiated renal injury mediated by the calpain escaping out of damaged PTCs. Immunohistochemical detection of renal calpain and its activity in the urine, over a time course after treatment with the LD 9 dose of DCVC, indicated progressive increase in leakage of calpain into the extracellular spaces of the injured PTCs of the non-diabetic (NDB) kidneys as compared to the DB kidneys. Calpastatin expression was minimally detected in the NDB kidneys, using immunohistochemistry, over the time course. On the other hand, consistently higher number of tubules in the DB kidney showed calpastatin expression over the time course. The lower leakage of calpain in the DB kidneys was commensurate with constitutively higher expression of calpastatin in the S-phase-laden PTCs of these mice. To test the protective role of newly divided/dividing PTCs, DB mice were given the anti-mitotic agent colchicine (CLC) (2 mg/kg and 1.5 mg/kg, i.p., on days 8 and 10 after STZ injection) prior to challenge with a LD 9 dose of DCVC, which led to 100% mortality by 48 h. Mortality was due to rapid progression of DCVC-initiated renal injury, suggesting that newly divided/dividing cells are instrumental in mitigating

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

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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.

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Role of the intrarenal renin-angiotensin system in the progression of renal disease.

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Urushihara, Maki; Kagami, Shoji

2017-09-01

The intrarenal renin-angiotensin system (RAS) has many well-documented pathophysiologic functions in both blood pressure regulation and renal disease development. Angiotensin II (Ang II) is the major bioactive product of the RAS. It induces inflammation, renal cell growth, mitogenesis, apoptosis, migration, and differentiation. In addition, Ang II regulates the gene expression of bioactive substances and activates multiple intracellular signaling pathways that are involved in renal damage. Activation of the Ang II type 1 (AT1) receptor pathway results in the production of proinflammatory mediators, intracellular formation of reactive oxygen species, cell proliferation, and extracellular matrix synthesis, which in turn facilities renal injury. Involvement of angiotensinogen (AGT) in intrarenal RAS activation and development of renal disease has previously been reported. Moreover, studies have demonstrated that the urinary excretion rates of AGT provide a specific index of the intrarenal RAS status. Enhanced intrarenal AGT levels have been observed in experimental models of renal disease, supporting the concept that AGT plays an important role in the development and progression of renal disease. In this review, we focus on the role of intrarenal RAS activation in the pathophysiology of renal disease. Additionally, we explored the potential of urinary AGT as a novel biomarker of intrarenal RAS status in renal disease.

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File list: DNS.Neu.50.AllAg.Induced_neural_progenitors [Chip-atlas[Archive

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File list: Pol.Adp.20.AllAg.Adipose_progenitor_cells [Chip-atlas[Archive

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File list: DNS.Neu.05.AllAg.Induced_neural_progenitors [Chip-atlas[Archive

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Invited review: mesenchymal progenitor cells in intramuscular connective tissue development.

Science.gov (United States)

Miao, Z G; Zhang, L P; Fu, X; Yang, Q Y; Zhu, M J; Dodson, M V; Du, M

2016-01-01

The abundance and cross-linking of intramuscular connective tissue contributes to the background toughness of meat, and is thus undesirable. Connective tissue is mainly synthesized by intramuscular fibroblasts. Myocytes, adipocytes and fibroblasts are derived from a common pool of progenitor cells during the early embryonic development. It appears that multipotent mesenchymal stem cells first diverge into either myogenic or non-myogenic lineages; non-myogenic mesenchymal progenitors then develop into the stromal-vascular fraction of skeletal muscle wherein adipocytes, fibroblasts and derived mesenchymal progenitors reside. Because non-myogenic mesenchymal progenitors mainly undergo adipogenic or fibrogenic differentiation during muscle development, strengthening progenitor proliferation enhances the potential for both intramuscular adipogenesis and fibrogenesis, leading to the elevation of both marbling and connective tissue content in the resulting meat product. Furthermore, given the bipotent developmental potential of progenitor cells, enhancing their conversion to adipogenesis reduces fibrogenesis, which likely results in the overall improvement of marbling (more intramuscular adipocytes) and tenderness (less connective tissue) of meat. Fibrogenesis is mainly regulated by the transforming growth factor (TGF) β signaling pathway and its regulatory cascade. In addition, extracellular matrix, a part of the intramuscular connective tissue, provides a niche environment for regulating myogenic differentiation of satellite cells and muscle growth. Despite rapid progress, many questions remain in the role of extracellular matrix on muscle development, and factors determining the early differentiation of myogenic, adipogenic and fibrogenic cells, which warrant further studies.

DNMT1 maintains progenitor function in self-renewing somatic tissue.

Science.gov (United States)

Sen, George L; Reuter, Jason A; Webster, Daniel E; Zhu, Lilly; Khavari, Paul A

2010-01-28

Progenitor cells maintain self-renewing tissues throughout life by sustaining their capacity for proliferation while suppressing cell cycle exit and terminal differentiation. DNA methylation provides a potential epigenetic mechanism for the cellular memory needed to preserve the somatic progenitor state through repeated cell divisions. DNA methyltransferase 1 (DNMT1) maintains DNA methylation patterns after cellular replication. Although dispensable for embryonic stem cell maintenance, the role for DNMT1 in maintaining the progenitor state in constantly replenished somatic tissues, such as mammalian epidermis, is unclear. Here we show that DNMT1 is essential for epidermal progenitor cell function. DNMT1 protein was found enriched in undifferentiated cells, where it was required to retain proliferative stamina and suppress differentiation. In tissue, DNMT1 depletion led to exit from the progenitor cell compartment, premature differentiation and eventual tissue loss. Genome-wide analysis showed that a significant portion of epidermal differentiation gene promoters were methylated in self-renewing conditions but were subsequently demethylated during differentiation. Furthermore, UHRF1 (refs 9, 10), a component of the DNA methylation machinery that targets DNMT1 to hemi-methylated DNA, is also necessary to suppress premature differentiation and sustain proliferation. In contrast, Gadd45A and B, which promote active DNA demethylation, are required for full epidermal differentiation gene induction. These data demonstrate that proteins involved in the dynamic regulation of DNA methylation patterns are required for progenitor maintenance and self-renewal in mammalian somatic tissue.

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File list: Oth.Adp.50.AllAg.Adipose_progenitor_cells [Chip-atlas[Archive

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File list: Oth.Adp.10.AllAg.Adipose_progenitor_cells [Chip-atlas[Archive

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Race, Racism, and Access to Renal Transplantation among African Americans.

Science.gov (United States)

Arriola, Kimberly Jacob

2017-01-01

There are clear and compelling racial disparities in access to renal transplant, which is the therapy of choice for many patients with end stage renal disease. This paper conceptualizes the role of racism (i.e., internalized, personally-mediated, and institutionalized) in creating and perpetuating these disparities at multiple levels of the social ecology by integrating two often-cited theories in the literature. Internalized racism is manifested at the intrapersonal level when, for example, African American patients devalue their self-worth, thereby not pursuing the most aggressive treatment available. Personally-mediated racism is manifested at the interpersonal level when, for example, physicians exhibit unconscious race bias that impacts their treatment decisions. One example of institutionalized racism being manifested at the institutional, community, and public policy levels is the longstanding existence of racial residential segregation and empirically established links between neighborhood racial composition and dialysis facility-level transplantation rates. This paper concludes with clinical, research, and policy recommendations.

File list: His.Neu.20.AllAg.Induced_neural_progenitors [Chip-atlas[Archive

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File list: His.Neu.10.AllAg.Induced_neural_progenitors [Chip-atlas[Archive

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Autologous fibrin glue as an encapsulating scaffold for delivery of retinal progenitor cells

Directory of Open Access Journals (Sweden)

Tamer Anwar Esmail Ahmed

2015-02-01

Full Text Available The retina is a highly sophisticated piece of the neural machinery that begins the translation of incoming light signals into meaningful visual information. Several degenerative diseases of the retina are characterized by photoreceptor loss and eventually lead to irreversible blindness. Regenerative medicine, using tissue engineering-based constructs to deliver progenitor cells or photoreceptors along with supporting carrier matrix is a promising approach for restoration of structure and function. Fresh fibrin glue (FG produced by the CryoSeal®FS system in combination with mouse retinal progenitor cells (RPCs were evaluated in this study. In vitro expanded RPCs isolated from postnatal mouse retina were encapsulated into FG and cultured in the presence of the protease inhibitor, tranexamic acid. Encapsulation of RPCs into FG did not show adverse effects on cell proliferation or cell survival. RPCs exhibited fibroblast-like morphology concomitantly with attachment to the encapsulating FG surface. They expressed α7 and β3 integrin subunits that could mediate attachment to fibrin matrix via an RGD independent mechanism. The three dimensional environment and the attachment surface provided by FG was associated with a rapid downregulation of the progenitor marker SOX2 and enhanced the expression of the differentiation markers CRX and recoverin. However, the in vitro culture conditions did not promote full differentiation into mature photoreceptors. Nevertheless, we have shown that autologous fibrin, when fabricated into a scaffold for RPCs for delivery to the retina, provides the cells with external cues that could potentially improve the differentiation events. Hence, transient encapsulation of RPCs into FG could be a valid and potential treatment strategy to promote retinal regeneration following degenerative diseases. However, further optimization is necessary to maximize the outcomes in terms of mature photoreceptors.

In vitro expansion of the mammary stem/progenitor cell population by xanthosine treatment

Directory of Open Access Journals (Sweden)

Choudhary Ratan K

2012-06-01

Full Text Available Abstract Background Mammary stem cells are critical for growth and maintenance of the mammary gland and therefore are of considerable interest for improving productivity and efficiency of dairy animals. Xanthosine treatment has been demonstrated to promote expansion of putative mammary stem cells in vivo, and hepatic and hair follicle stem cells in vitro. In the latter, xanthosine promoted the symmetrical division of hepatic and hair follicle stem cells. The objective of this study was to determine if treating primary cultures of bovine mammary epithelial cells (MEC with xanthosine increases the stem/progenitor cell population by promoting symmetrical division of mammary stem cells. Results In vitro treatment with xanthosine increased the population of MEC during the exponential phase of cell growth, reducing the doubling time from 86 h in control cultures to 60 h in xanthosine-treated cultures. The bromodeoxyuridine (BrdU labeling index and the proportion of MEC in S-phase both were increased by xanthosine treatment, indicating that increased cell accretion was due to increased cell proliferation. Analysis of daughter-pairs indicated that xanthosine promoted a shift from asymmetric to symmetric cell division. Moreover, the 30 % increase in symmetric cell division was concomitant with an increase in the proportion of MEC that were positive for a putative stem cell marker (FNDC3B and a trend toward increased telomerase activity. These results suggest that xanthosine treatment in vitro can increase cell proliferation, promote symmetric cell division and enhance stem/progenitor cell activity. Conclusions Xanthosine treatment increased the proliferation rate of bovine MEC in vitro. This was likely to be mediated by an increase in the proportion of stem/progenitor cells in the MEC population due to promotion of symmetrical stem cell division by xanthosine.

Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients

NARCIS (Netherlands)

Sotomayor, C. G.; Eisenga, Michele F; Neto, Antonio W Gomes; Ozyilmaz, Akin; Gans, Rijk O B; Jong, Wilhelmina H A de; Zelle, Dorien M; Berger, Stefan P; Gaillard, Carlo A J M; Navis, Gerjan J.; Bakker, Stephan J. L.

2017-01-01

Vitamin C may reduce inflammation and is inversely associated with mortality in the general population. We investigated the association of plasma vitamin C with all-cause mortality in renal transplant recipients (RTR); and whether this association would be mediated by inflammatory biomarkers.

Lycium chinense leaves extract ameliorates diabetic nephropathy by suppressing hyperglycemia mediated renal oxidative stress and inflammation.

Science.gov (United States)

Olatunji, Opeyemi Joshua; Chen, Hongxia; Zhou, Yifeng

2018-06-01

Diabetic nephropathy is one of the most serious and most frequently encountered diabetic complication, accounting for the highest cause of end-stage renal disease. This present study was aimed at exploring the protective/attenuative effect of Lycium chinense leaf extract (MELC) on streptozotocin induced diabetic nephropathy in experimental Sprague Dawley rats. The oral administration of diabetic rats with MELC markedly ameliorated renal dysfunction as observed in the significant reduction in the serum levels of creatinine, blood urea nitrogen (BUN), albumin and TGF-β1 as compared to the untreated diabetic control rats. In addition, the elevated levels of renal oxidative stress markers and pro-inflammatory parameters (GSH, SOD, CAT, MDA, TNF-α, IL-6 and IL-1β) were significantly reduced in MELC treated diabetic rats. The results obtained in this study suggests that L. chinense leaf might have the potential as possible pharmacological agent against diabetic nephropathy by suppressing renal oxidative stress and inflammation. Copyright © 2018. Published by Elsevier Masson SAS.

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File list: Oth.Neu.20.AllAg.Induced_neural_progenitors [Chip-atlas[Archive

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TYPE IIb SUPERNOVAE WITH COMPACT AND EXTENDED PROGENITORS

International Nuclear Information System (INIS)

Chevalier, Roger A.; Soderberg, Alicia M.

2010-01-01

The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova that has a more compact progenitor with a lower density, probably fast, wind. Distinguishing features of the compact category are weak optical emission from the shock heated envelope at early times, nonexistent or very weak H emission in the late nebular phase, rapidly evolving radio emission, rapid expansion of the radio shell, and expected nonthermal as opposed to thermal X-ray emission. Type IIb supernovae that have one or more of these features include SNe 1996cb, 2001ig, 2003bg, 2008ax, and 2008bo. All of these with sufficient radio data (the last four) show evidence for presupernova wind variability. We estimate a progenitor envelope radius ∼1 x 10 11 cm for SN 2008ax, a value consistent with a compact Wolf-Rayet progenitor. Supernovae in the SN 1993J extended category include SN 2001gd and probably the Cas A supernova. We suggest that the compact Type IIb events be designated Type cIIb and the extended ones Type eIIb. The H envelope mass dividing these categories is ∼0.1 M sun .

Designing N-halamine based antibacterial surface on polymers: Fabrication, characterization, and biocidal functions

Energy Technology Data Exchange (ETDEWEB)

Chen Yong, E-mail: ychen168@126.com [Department of Applied Chemistry, College of Chemical and Environmental Engineering, Shandong University of Science and Technology, 579 Qianwangang Rd., Huangdao Zone, Qingdao 266510 (China); Han Qiuxia [Department of Biological Engineering, College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266510 (China)

2011-05-01

We demonstrate a valuable method to generate reactive groups on inert polymer surfaces and bond antibacterial agents for biocidal ability. Polystyrene (PS) surfaces were functionalized by spin coating of sub-monolayer and monolayer films of poly(styrene-b-tert-butyl acrylate) (PS-PtBA) block copolymer from solutions in toluene. PS-PtBA self-assembled to a bilayer structure on PS that contains a surface layer of the PtBA blocks ordering at the air-polymer interface and a bottom layer of the PS blocks entangling with the PS substrate. The thickness of PtBA layer could be linearly controlled by the concentration of the spin coating solution and a 2.5 nm saturated monolayer coverage of PtBA was achieved at 0.35% (w/w). Carboxyl groups were generated by exposing the tert-butyl ester groups of PtBA on saturated surface to trifluoroacetic acid (TFA) to bond tert-butylamine via amide bonds that were further chlorinated to N-halamine with NaOCl solution. The density of N-halamine on the chlorinated surface was calculated to be 1.05 x 10{sup -5} mol/m{sup 2} by iodimetric/thiosulfate titration. Presented data showed the N-halamine surface provided powerful antibacterial activities against Staphylococcus aureus and Escherichia coli. Over 50% of the chlorine lost after UVA irradiation could be regained upon rechlorination. This design concept can be virtually applied to any inert polymer by choosing appropriate block copolymers and antibacterial agents to attain desirable biocidal activity.

Autocrine CSF-1 and CSF-1 Receptor Co-expression Promotes Renal Cell Carcinoma Growth

Science.gov (United States)

Menke, Julia; Kriegsmann, Jörg; Schimanski, Carl Christoph; Schwartz, Melvin M.; Schwarting, Andreas; Kelley, Vicki R.

2011-01-01

Renal cell carcinoma is increasing in incidence but the molecular mechanisms regulating its growth remain elusive. Co-expression of the monocytic growth factor CSF-1 and its receptor CSF-1R on renal tubular epithelial cells (TEC) will promote proliferation and anti-apoptosis during regeneration of renal tubules. Here we show that a CSF-1-dependent autocrine pathway is also responsible for the growth of renal cell carcinoma (RCC). CSF-1 and CSF-1R were co-expressed in RCC and TEC proximally adjacent to RCC. CSF-1 engagement of CSF-1R promoted RCC survival and proliferation and reduced apoptosis, in support of the likelihood that CSF-1R effector signals mediate RCC growth. In vivo CSF-1R blockade using a CSF-1R tyrosine kinase inhibitor decreased RCC proliferation and macrophage infiltration in a manner associated with a dramatic reduction in tumor mass. Further mechanistic investigations linked CSF-1 and EGF signaling in RCC. Taken together, our results suggest that budding RCC stimulates the proximal adjacent microenvironment in the kidney to release mediators of CSF-1, CSF-1R and EGF expression in RCC. Further, our findings imply that targeting CSF-1/CSF-1R signaling may be therapeutically effective in RCC. PMID:22052465

Exercise renogram. A new approach documents renal involvement in systemic hypertension

International Nuclear Information System (INIS)

Clorius, J.H.; Schmidlin, P.

1983-01-01

Hippurate functional scintiscans were obtained in 51 hypertensive patients and in 15 controls. The authors investigated the influence that posture and exercise have on hippurate kinetics in patients with hypertension. A posture- or exercise-induced disturbance of renal hippurate transport was sought. All persons were examined in prone and standing positions, as well as during exercise. When prone and upright renograms were compared, 24% of the hypertensives demonstrated bilateral orthostatic renal dysfunction. Exercise caused the hippurate transport disturbance to increase. Fifty-seven percent of all hypertensives developed evidence of marked, bilateral, renal dysfunction during ergometric stress, so that exercise renography was shown to be a more sensitive test of the presence of transient tubular dysfunction in hypertension than the standing renogram. In normotensive controls the hippurate functional scintigram failed to be influenced by posture and exercise. The results suggest presence in hypertension of transient, posture- and exercise-mediated alterations of renal cortical blood flow

Shexiang Baoxin pills promotes angiogenesis in myocardial infarction rats via up-regulation of 20-HETE-mediated endothelial progenitor cells mobilization.

Science.gov (United States)

Huang, Feifei; Liu, Yang; Yang, Xia; Che, Di; Qiu, Kaifeng; Hammock, Bruce D; Wang, Jingfeng; Wang, Mong-Heng; Chen, Jie; Huang, Hui

2017-08-01

Therapeutic angiogenesis is a pivotal strategy for ischemic heart disease. The aim of the present study was to determine the effect and molecular mechanism of Shexiang Baoxin pills, a widely-used traditional Chinese medicine for ischemic heart disease, on angiogenesis in a rat model of myocardial infarction (MI). We used the occlusion of left anterior descending coronary artery of Sprague-Dawley rats as a model of MI. The MI rats were treated with distilled water, Shexiang Baoxin pills, or Shexiang Baoxin pills + HET0016 (a selective blocker of the biosynthesis of 20-hydroxyeicosatetraenoic acid (20-HETE) at 10 mg/kg/day), respectively. Sham-operated rats were used as controls. Treatment with Shexiang Baoxin pills increases the level of serum 20-HETE in MI rats, which can be suppressed by HET0016 treatment. Shexiang Baoxin pills shows cardio-protective effects on MI rats, including improving cardiac function, decreasing infarction area, and promoting angiogenesis in peri-infarct area. The protective effects of Shexiang Baoxin pills are partly inhibited by HET0016. Furthermore, Shexiang Baoxin pills enhances the number of circulating endothelial progenitor cells (EPCs) and the expression of the vascular endothelial growth factor (VEGF), based on immunohistochemical analysis, in peri-infarct area of MI rats, which is partly suppressed by HET0016. Shexiang Baoxin pills may partially participate in angiogenesis in MI rats. The protective mechanism of Shexiang Baoxin pills may be mediated via up-regulation of 20-HETE, which promotes EPCs mobilization and VEGF expression. Copyright © 2017 Elsevier B.V. All rights reserved.

TLR-mediated albuminuria needs TNFα-mediated cooperativity between TLRs present in hematopoietic tissues and CD80 present on non-hematopoietic tissues in mice

Directory of Open Access Journals (Sweden)

Nidhi Jain

2016-06-01

Full Text Available Transient albuminuria induced by pathogen-associated molecular patterns (PAMPs in mice through engagement of Toll-like receptors (TLRs is widely studied as a partial model for some forms of human nephrotic syndrome (NS. In addition to TLRs, CD80 has been shown to be essential for PAMP-mediated albuminuria. However, the mechanistic relationships between TLRs, CD80 and albuminuria remain unclear. Here, we show that albuminuria and CD80-uria induced in mice by many TLR ligands are dependent on the expression of TLRs and their downstream signalling intermediate MyD88 exclusively in hematopoietic cells and, conversely, on CD80 expression exclusively in non-hematopoietic cells. TNFα is crucial for TLR-mediated albuminuria and CD80-uria, and induces CD80 expression in cultured renal podocytes. IL-10 from hematopoietic cells ameliorates TNFα production, albuminuria and CD80-uria but does not prevent TNFα-mediated induction of podocyte CD80 expression. Chitohexaose, a small molecule originally of parasite origin, mediates TLR4-dependent anti-inflammatory responses, and blocks TLR-mediated albuminuria and CD80-uria through IL-10. Thus, TNFα is a prominent mediator of renal CD80 induction and resultant albuminuria in this model, and small molecules modulating TLR-mediated inflammatory activation might have contributory or adjunct therapeutic potential in some contexts of NS development.

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File list: Oth.Neu.20.AllAg.Neural_progenitor_cells [Chip-atlas[Archive

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File list: His.Neu.20.AllAg.Neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: Oth.Oth.10.AllAg.Multipotent_otic_progenitor [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: His.Neu.05.AllAg.Neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Neu.05.AllAg.Neural_progenitor_cells mm9 Histone Neural Neural progenitor cells... SRX315277,SRX667383,SRX668241,SRX315278,SRX315276 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Neural_progenitor_cells.bed ...

Proof of region-specific multipotent progenitors in human breast epithelia

DEFF Research Database (Denmark)

Fridriksdottir, Agla J; Villadsen, René; Morsing, Mikkel

2017-01-01

in luminal progenitors to interrogate the differentiation repertoire of candidate stem cells in TDLUs. We show that stem-like activity in serial passage culture and in vivo breast morphogenesis relies on the preservation of a myoepithelial phenotype. By enrichment for region-specific progenitors, we identify...

KARAKTERISTIK AIR ASAM TAMBANG DI LINGKUNGAN TAMBANG PIT 1 BANGKO BARAT, TANJUNG ENIM SUMATERA SELATAN SEBUAH STUDI KASUS ASAM TAMBANG

OpenAIRE

Tresnadi, Hidir

2011-01-01

In Coal Mine Pit 1, Bangko Barat, Tanjung Enim, South Sumatera mine activity lowered the water pH in the effluent water of the mine. So the Mine Environmet Managemet of PTBA try to raise the pH to meet Kep Men Neg LH No 113 Tahun 2003. This study attempt to characterize the performance of the water treatment,which managed by acid-mine dranage management of the PTBA. Some water samples was taken in the study area, such as the passive treatment in Pit 1 Bangko Barat, rainwater pond near by, lak...

Karakteristik Air Asam Tambang Di Lingkungan Tambang Pit 1 Bangko Barat, Tanjung Enim Sumatera Selatan Sebuah Studi Kasus Asam Tambang

OpenAIRE

Tresnadi, Hidir

2008-01-01

In Coal Mine Pit 1, Bangko Barat, Tanjung Enim, South Sumatera mine activity lowered the water pH in the effluent water of the mine. So the Mine Environmet Managemet of PTBA try to raise the pH to meet Kep Men Neg LH No 113 Tahun 2003. This study attempt to characterize the performance of the water treatment,which managed by acid-mine dranage management of the PTBA. Some water samples was taken in the study area, such as the passive treatment in Pit 1 Bangko Barat, rainwater pond near by, lak...

Exercise training normalizes renal blood flow responses to acute hypoxia in experimental heart failure: role of the α1-adrenergic receptor.

Science.gov (United States)

Pügge, Carolin; Mediratta, Jai; Marcus, Noah J; Schultz, Harold D; Schiller, Alicia M; Zucker, Irving H

2016-02-01

Recent data suggest that exercise training (ExT) is beneficial in chronic heart failure (CHF) because it improves autonomic and peripheral vascular function. In this study, we hypothesized that ExT in the CHF state ameliorates the renal vasoconstrictor responses to hypoxia and that this beneficial effect is mediated by changes in α1-adrenergic receptor activation. CHF was induced in rabbits. Renal blood flow (RBF) and renal vascular conductance (RVC) responses to 6 min of 5% isocapnic hypoxia were assessed in the conscious state in sedentary (SED) and ExT rabbits with CHF with and without α1-adrenergic blockade. α1-adrenergic receptor expression in the kidney cortex was also evaluated. A significant decline in baseline RBF and RVC and an exaggerated renal vasoconstriction during acute hypoxia occurred in CHF-SED rabbits compared with the prepaced state (P renal denervation (DnX) blocked the hypoxia-induced renal vasoconstriction in CHF-SED rabbits. α1-adrenergic protein in the renal cortex of animals with CHF was increased in SED animals and normalized after ExT. These data provide evidence that the acute decline in RBF during hypoxia is caused entirely by the renal nerves but is only partially mediated by α1-adrenergic receptors. Nonetheless, α1-adrenergic receptors play an important role in the beneficial effects of ExT in the kidney. Copyright © 2016 the American Physiological Society.

THE TYPE IIb SUPERNOVA 2011dh FROM A SUPERGIANT PROGENITOR

International Nuclear Information System (INIS)

Bersten, Melina C.; Nomoto, Ken'ichi; Folatelli, Gastón; Maeda, Keiichi; Benvenuto, Omar G.; Ergon, Mattias; Sollerman, Jesper; Benetti, Stefano; Ochner, Paolo; Tomasella, Lina; Botticella, Maria Teresa; Fraser, Morgan; Kotak, Rubina

2012-01-01

A set of hydrodynamical models based on stellar evolutionary progenitors is used to study the nature of SN 2011dh. Our modeling suggests that a large progenitor star—with R ∼ 200 R ☉ —is needed to reproduce the early light curve (LC) of SN 2011dh. This is consistent with the suggestion that the yellow super-giant star detected at the location of the supernova (SN) in deep pre-explosion images is the progenitor star. From the main peak of the bolometric LC and expansion velocities, we constrain the mass of the ejecta to be ≈2 M ☉ , the explosion energy to be E = (6-10) × 10 50 erg, and the 56 Ni mass to be approximately 0.06 M ☉ . The progenitor star was composed of a helium core of 3-4 M ☉ and a thin hydrogen-rich envelope of ≈0.1M ☉ with a main-sequence mass estimated to be in the range of 12-15 M ☉ . Our models rule out progenitors with helium-core masses larger than 8 M ☉ , which correspond to M ZAMS ∼> 25M ☉ . This suggests that a single star evolutionary scenario for SN 2011dh is unlikely.

Low functional programming of renal AT{sub 2}R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure

Energy Technology Data Exchange (ETDEWEB)

Ao, Ying [Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Disorder, Wuhan 430071 (China); Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na [Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan 430071 (China); Li, Bin [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Yang, Shuailong; Xia, Liping; Wu, Yong [Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan 430071 (China); Wang, Linlong [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); He, Zheng [Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan 430071 (China); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Disorder, Wuhan 430071 (China)

2015-09-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT{sub 2}R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT{sub 1a}R)/AT{sub 2}R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT{sub 2}R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT{sub 2}R might mediate the developmental origin of adult glomerulosclerosis. - Highlights: • Prenatal caffeine exposure induces glomerulosclerosis in adult offspring. • Prenatal caffeine

Na+-K+ pump in chronic renal failure

International Nuclear Information System (INIS)

Deepak, K.; Kahn, T.

1987-01-01

This review summarizes the evidence for the defect in Na + -K + pump in chronic renal failure, considers the role of various factors in causing this defect, and discusses the clinical implications thereof. Intracellular Na is elevated in erythrocytes, leukocytes, and muscle cells from some patients with chronic renal failure (CRF). Recent evidence suggest that this elevation of cell Na may be, in large part, a consequence of decreased number of Na + -K + pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na + , and this improvement is contemporaneous with an increase in the number of Na + -K + pump sites per cell. In erythrocytes with normal cell Na + , acute hemodialysis increases the rate of 22 Na + and 42 K + transport. Many factors such as the presence of retained toxic metabolite or circulating inhibitor in the uremic plasma, or biochemical changes produced by acute hemodialysis, may explain this finding. In cells with high cell Na + , the pump-mediated 42 K + transport is normalized at the expense of a raised cell Na + . The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na + -K + pump. The authors discuss the role of hormonal abnormalities and circulating inhibitors, which may cause an acute inhibition of the pump and of other factors such as K + depletion, which may cause more chronic alterations. The implications of alteration of Na + and K + pump transport and raised cell Na + on other non-pump-mediated transport pathways are discussed. Raised cell Na + may be a marker for the adequacy of maintenance dialysis in patients with end-stage renal failure

EVOLUTION OF PROGENITORS FOR ELECTRON CAPTURE SUPERNOVAE

International Nuclear Information System (INIS)

Takahashi, Koh; Umeda, Hideyuki; Yoshida, Takashi

2013-01-01

We provide progenitor models for electron capture supernovae (ECSNe) with detailed evolutionary calculation. We include minor electron capture nuclei using a large nuclear reaction network with updated reaction rates. For electron capture, the Coulomb correction of rates is treated and the contribution from neutron-rich isotopes is taken into account in each nuclear statistical equilibrium (NSE) composition. We calculate the evolution of the most massive super asymptotic giant branch stars and show that these stars undergo off-center carbon burning and form ONe cores at the center. These cores become heavier up to the critical mass of 1.367 M ☉ and keep contracting even after the initiation of O+Ne deflagration. Inclusion of minor electron capture nuclei causes convective URCA cooling during the contraction phase, but the effect on the progenitor evolution is small. On the other hand, electron capture by neutron-rich isotopes in the NSE region has a more significant effect. We discuss the uniqueness of the critical core mass for ECSNe and the effect of wind mass loss on the plausibility of our models for ECSN progenitors.

Aldosterone dysregulation with aging predicts renal vascular function and cardiovascular risk.

Science.gov (United States)

Brown, Jenifer M; Underwood, Patricia C; Ferri, Claudio; Hopkins, Paul N; Williams, Gordon H; Adler, Gail K; Vaidya, Anand

2014-06-01

Aging and abnormal aldosterone regulation are both associated with vascular disease. We hypothesized that aldosterone dysregulation influences the age-related risk of renal vascular and cardiovascular disease. We conducted an analysis of 562 subjects who underwent detailed investigations under conditions of liberal and restricted dietary sodium intake (1124 visits) in the General Clinical Research Center. Aldosterone regulation was characterized by the ratio of maximal suppression to stimulation (supine serum aldosterone on a liberal sodium diet divided by the same measure on a restricted sodium diet). We previously demonstrated that higher levels of this Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI) indicate greater aldosterone dysregulation. Renal plasma flow (RPF) was determined via p-aminohippurate clearance to assess basal renal hemodynamics and the renal vascular responses to dietary sodium manipulation and angiotensin II infusion. Cardiovascular risk was calculated using the Framingham Risk Score. In univariate linear regression, older age (β=-4.60; Page and SASSI, where the inverse relationship between SASSI and RPF was most apparent with older age (Page may interact to mediate renal vascular disease. Our findings suggest that the combination of aldosterone dysregulation and renal vascular dysfunction could additively increase the risk of future cardiovascular outcomes; therefore, aldosterone dysregulation may represent a modifiable mechanism of age-related vascular disease.

Continuous renal replacement therapy improves renal recovery from acute renal failure.

Science.gov (United States)

Jacka, Michael J; Ivancinova, Xenia; Gibney, R T Noel

2005-03-01

Acute renal failure (ARF) occurs in up to 10% of critically ill patients, with significant associated morbidity and mortality. The optimal mode of renal replacement therapy (RRT) remains controversial. This retrospective study compared continuous renal replacement therapy (CRRT) and intermittent hemodialysis (IHD) for RRT in terms of intensive care unit (ICU) and hospital mortality, and renal recovery. We reviewed the records of all patients undergoing RRT for the treatment of ARF over a 12-month period. Patients were compared according to mode of RRT, demographics, physiologic characteristics, and outcomes of ICU and hospital mortality and renal recovery using the Chi square, Student's t test, and multiple logistic regression as appropriate. 116 patients with renal insufficiency underwent RRT during the study period. Of these, 93 had ARF. The severity of illness of CRRT patients was similar to that of IHD patients using APACHE II (25.1 vs 23.5, P = 0.37), but they required significantly more intensive nursing (therapeutic intervention scale 47.8 vs 37.6, P = 0.0001). Mortality was associated with lower pH at presentation (P = 0.003) and increasing age (P = 0.03). Renal recovery was significantly more frequent among patients initially treated with CRRT (21/24 vs 5/14, P = 0.0003). Further investigation to define optimal timing, dose, and duration of RRT may be beneficial. Although further study is needed, this study suggests that renal recovery may be better after CRRT than IHD for ARF. Mortality was not affected significantly by RRT mode.

File list: His.Adp.10.AllAg.Adipose_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Adp.10.AllAg.Adipose_progenitor_cells mm9 Histone Adipocyte Adipose progenitor ...cells SRX127409,SRX127394,SRX127396,SRX127407,SRX127383,SRX127381 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.10.AllAg.Adipose_progenitor_cells.bed ...

File list: His.Adp.05.AllAg.Adipose_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Adp.05.AllAg.Adipose_progenitor_cells mm9 Histone Adipocyte Adipose progenitor ...cells SRX127409,SRX127407,SRX127394,SRX127396,SRX127383,SRX127381 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.05.AllAg.Adipose_progenitor_cells.bed ...

Maintenance of neural progenitor cell stemness in 3D hydrogels requires matrix remodelling

Science.gov (United States)

Madl, Christopher M.; Lesavage, Bauer L.; Dewi, Ruby E.; Dinh, Cong B.; Stowers, Ryan S.; Khariton, Margarita; Lampe, Kyle J.; Nguyen, Duong; Chaudhuri, Ovijit; Enejder, Annika; Heilshorn, Sarah C.

2017-12-01

Neural progenitor cell (NPC) culture within three-dimensional (3D) hydrogels is an attractive strategy for expanding a therapeutically relevant number of stem cells. However, relatively little is known about how 3D material properties such as stiffness and degradability affect the maintenance of NPC stemness in the absence of differentiation factors. Over a physiologically relevant range of stiffness from ~0.5 to 50 kPa, stemness maintenance did not correlate with initial hydrogel stiffness. In contrast, hydrogel degradation was both correlated with, and necessary for, maintenance of NPC stemness. This requirement for degradation was independent of cytoskeletal tension generation and presentation of engineered adhesive ligands, instead relying on matrix remodelling to facilitate cadherin-mediated cell-cell contact and promote β-catenin signalling. In two additional hydrogel systems, permitting NPC-mediated matrix remodelling proved to be a generalizable strategy for stemness maintenance in 3D. Our findings have identified matrix remodelling, in the absence of cytoskeletal tension generation, as a previously unknown strategy to maintain stemness in 3D.

Drug discovery for Diamond-Blackfan anemia using reprogrammed hematopoietic progenitors

Science.gov (United States)

Doulatov, Sergei; Vo, Linda T.; Macari, Elizabeth R.; Wahlster, Lara; Kinney, Melissa A.; Taylor, Alison M.; Barragan, Jessica; Gupta, Manav; McGrath, Katherine; Lee, Hsiang-Ying; Humphries, Jessica M.; DeVine, Alex; Narla, Anupama; Alter, Blanche P.; Beggs, Alan H.; Agarwal, Suneet; Ebert, Benjamin L.; Gazda, Hanna T.; Lodish, Harvey F.; Sieff, Colin A.; Schlaeger, Thorsten M.; Zon, Leonard I.; Daley, George Q.

2017-01-01

Diamond-Blackfan anemia (DBA) is a congenital disorder characterized by the failure of erythroid progenitor differentiation, severely curtailing red blood cell production. Because many DBA patients fail to respond to corticosteroid therapy, there is considerable need for therapeutics for this disorder. Identifying therapeutics for DBA requires circumventing the paucity of primary patient blood stem and progenitor cells. To this end, we adopted a reprogramming strategy to generate expandable hematopoietic progenitor cells from induced pluripotent stem cells (iPSCs) from DBA patients. Reprogrammed DBA progenitors recapitulate defects in erythroid differentiation, which were rescued by gene complementation. Unbiased chemical screens identified SMER28, a small-molecule inducer of autophagy, which enhanced erythropoiesis in a range of in vitro and in vivo models of DBA. SMER28 acted through autophagy factor ATG5 to stimulate erythropoiesis and up-regulate expression of globin genes. These findings present an unbiased drug screen for hematological disease using iPSCs and identify autophagy as a therapeutic pathway in DBA. PMID:28179501

Luminal progenitors restrict their lineage potential during mammary gland development.

Science.gov (United States)

Rodilla, Veronica; Dasti, Alessandro; Huyghe, Mathilde; Lafkas, Daniel; Laurent, Cécile; Reyal, Fabien; Fre, Silvia

2015-02-01

The hierarchical relationships between stem cells and progenitors that guide mammary gland morphogenesis are still poorly defined. While multipotent basal stem cells have been found within the myoepithelial compartment, the in vivo lineage potential of luminal progenitors is unclear. Here we used the expression of the Notch1 receptor, previously implicated in mammary gland development and tumorigenesis, to elucidate the hierarchical organization of mammary stem/progenitor cells by lineage tracing. We found that Notch1 expression identifies multipotent stem cells in the embryonic mammary bud, which progressively restrict their lineage potential during mammary ductal morphogenesis to exclusively generate an ERαneg luminal lineage postnatally. Importantly, our results show that Notch1-labelled cells represent the alveolar progenitors that expand during pregnancy and survive multiple successive involutions. This study reveals that postnatal luminal epithelial cells derive from distinct self-sustained lineages that may represent the cells of origin of different breast cancer subtypes.

Renal cells activate the platelet receptor CLEC-2 through podoplanin

Science.gov (United States)

Christou, Charita M.; Pearce, Andrew C.; Watson, Aleksandra A.; Mistry, Anita R.; Pollitt, Alice Y.; Fenton-May, Angharad E.; Johnson, Louise A.; Jackson, David G.; Watson, Steve P.; O'Callaghan, Chris A.

2009-01-01

We have recently shown that the C-type lectin-like receptor, CLEC-2, is expressed on platelets and that it mediates powerful platelet aggregation by the snake venom toxin, rhodocytin. In addition, we have provided indirect evidence for an endogenous ligand for CLEC-2 in renal cells expressing human immunodeficiency virus type 1 (HIV-1). This putative ligand facilitates transmission of HIV through its incorporation into the viral envelope and binding to CLEC-2 on platelets. The aim of this study was to identify the ligand on these cells which binds to CLEC-2 on platelets. Recombinant CLEC-2 exhibits specific binding to 293T cells in which the HIV can be grown. Further, 293T cells activate both platelets and CLEC-2-transfected DT-40 B cells. The transmembrane protein podoplanin was identified on 293T cells and demonstrated to mediate both binding of 293T cells to CLEC-2 and 293T cell activation of CLEC-2-transfected DT-40 B cells. Podoplanin is expressed on renal cells (podocytes). Further, a direct interaction between CLEC-2 and podoplanin was confirmed using surface plasmon resonance and was shown to be independent of glycosylation of CLEC-2. The interaction has an affinity of 24.5 ± 3.7μM. The present study identifies podoplanin as a ligand for CLEC-2 on renal cells. PMID:18215137

Angiopoietin-like protein 2 increases renal fibrosis by accelerating transforming growth factor-β signaling in chronic kidney disease.

Science.gov (United States)

Morinaga, Jun; Kadomatsu, Tsuyoshi; Miyata, Keishi; Endo, Motoyoshi; Terada, Kazutoyo; Tian, Zhe; Sugizaki, Taichi; Tanigawa, Hiroki; Zhao, Jiabin; Zhu, Shunshun; Sato, Michio; Araki, Kimi; Iyama, Ken-ichi; Tomita, Kengo; Mukoyama, Masashi; Tomita, Kimio; Kitamura, Kenichiro; Oike, Yuichi

2016-02-01

Renal fibrosis is a common pathological consequence of chronic kidney disease (CKD) with tissue fibrosis closely associated with chronic inflammation in numerous pathologies. However, molecular mechanisms underlying that association, particularly in the kidney, remain unclear. Here, we determine whether there is a molecular link between chronic inflammation and tissue fibrosis in CKD progression. Histological analysis of human kidneys indicated abundant expression of angiopoietin-like protein 2 (ANGPTL2) in renal tubule epithelial cells during progression of renal fibrosis. Numerous ANGPTL2-positive renal tubule epithelial cells colocalized with cells positive for transforming growth factor (TGF)-β1, a critical mediator of tissue fibrosis. Analysis of M1 collecting duct cells in culture showed that TGF-β1 increases ANGPTL2 expression by attenuating its repression through microRNA-221. Conversely, ANGPTL2 increased TGF-β1 expression through α5β1 integrin-mediated activation of extracellular signal-regulated kinase. Furthermore, ANGPTL2 deficiency in a mouse unilateral ureteral obstruction model significantly reduced renal fibrosis by decreasing TGF-β1 signal amplification in kidney. Thus, ANGPTL2 and TGF-β1 positively regulate each other as renal fibrosis progresses. Our study provides insight into molecular mechanisms underlying chronic inflammation and tissue fibrosis and identifies potential therapeutic targets for CKD treatment. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Renal cell carcinoma in patient with crossed fused renal ectopia

Directory of Open Access Journals (Sweden)

Ozgur Cakmak

2016-01-01

Full Text Available Primary renal cell carcinomas have rarely been reported in patients with crossed fused renal ectopia. We presented a patient with right to left crossed fused kidney harbouring renal tumor. The most frequent tumor encountered in crossed fused renal ectopia is renal cell carcinoma. In this case, partial nephrectomy was performed which pave way to preservation of the uninvolved both renal units. Due to unpredictable anatomy, careful preoperative planning and meticulous delineation of renal vasculature is essential for preservation of the uninvolved renal units.

A review of dietary supplement-induced renal dysfunction.

Science.gov (United States)

Gabardi, Steven; Munz, Kristin; Ulbricht, Catherine

2007-07-01

Complementary and alternative medicine (CAM) is a multibillion-dollar industry. Almost half of the American population uses some form of CAM, with many using them in addition to prescription medications. Most patients fail to inform their health care providers of their CAM use, and physicians rarely inquire. Annually, thousands of dietary supplement-induced adverse events are reported to Poison Control Centers nationwide. CAM manufacturers are not responsible for proving safety and efficacy, because the Food and Drug Administration does not regulate them. However, concern exists surrounding the safety of CAM. A literature search using MEDLINE and EMBASE was undertaken to explore the impact of CAM on renal function. English-language studies and case reports were selected for inclusion but were limited to those that consisted of human subjects, both adult and pediatric. This review provides details on dietary supplements that have been associated with renal dysfunction and focuses on 17 dietary supplements that have been associated with direct renal injury, CAM-induced immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, and hepatorenal syndrome. It is concluded that it is imperative that use of dietary supplements be monitored closely in all patients. Health care practitioners must take an active role in identifying patients who are using CAM and provide appropriate patient education.

Chemical chaperon 4-phenylbutyrate protects against the endoplasmic reticulum stress-mediated renal fibrosis in vivo and in vitro.

Science.gov (United States)

Liu, Shing-Hwa; Yang, Ching-Chin; Chan, Ding-Cheng; Wu, Cheng-Tien; Chen, Li-Ping; Huang, Jenq-Wen; Hung, Kuan-Yu; Chiang, Chih-Kang

2016-04-19

Renal tubulointerstitial fibrosis is the common and final pathologic change of kidney in end-stage renal disease. Interesting, endoplasmic reticulum (ER) stress is known to contribute to the pathophysiological mechanisms during the development of renal fibrosis. Here, we investigated the effects of chemical chaperon sodium 4-phenylbutyrate (4-PBA) on renal fibrosis in vivo and in vitro. In a rat unilateral ureteral obstruction (UUO) model, 4-PBA mimicked endogenous ER chaperon in the kidneys and significantly reduced glucose regulated protein 78 (GRP78), CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), activating transcription factor 4 (ATF4), and phosphorylated JNK protein expressions as well as restored spliced X-box-binding protein 1 (XBP1) expressions in the kidneys of UUO rats. 4-PBA also attenuated the increases of α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF) protein expressions, tubulointerstitial fibrosis, and apoptosis in the kidneys of UUO rats. Moreover, transforming growth factor (TGF)-β markedly increased ER stress-associated molecules, profibrotic factors, and apoptotic markers in the renal tubular cells (NRK-52E), all of which could be significantly counteracted by 4-PBA treatment. 4-PBA also diminished TGF-β-increased CTGF promoter activity and CTGF mRNA expression in NRK-52E cells. Taken together, our results indicated that 4-PBA acts as an ER chaperone to ameliorate ER stress-induced renal tubular cell apoptosis and renal fibrosis.

Efficacy of prophylactic irradiation in altering renal allograft survival

International Nuclear Information System (INIS)

Faber, R.; Johnson, H.K.; Braren, H.V.; Richie, R.E.

1974-01-01

Renal allograft rejection is a complex phenomenon involving both cell-mediated and humoral antibody responses. Most transplant programs have used a combination of therapeutic modalites to combat the immune system in an attempt to prolong both allograft and patient survival. Corticosteroids (methylprednisolone (Solu-Medrol) and prednisone and azathioprine (Imuran) are widely accepted as immunosuppressive drugs; however, both are non-specific and have the disadvantage of compromising the recipients' defense mechanisms. Nevertheless, these drugs have proved to be essential to the success of renal transplantation and they are routinely used while the efficacy of other modalities continues to be evaluated. We could find no reports of a prospective study to evaluate the efficacy of prophylactic irradiation in the complex therapeutic situation of renal transplantation with the only variable being the administration of local graft irradiation. The purpose of this study was to evaluate prophylactic graft irradiation for its effectiveness in preventing graft rejection in conjunction with Imuran and corticosteroids

Stromal Cells Act as Guardians for Endothelial Progenitors by Reducing Their Immunogenicity After Co-Transplantation.

Science.gov (United States)

Souidi, Naima; Stolk, Meaghan; Rudeck, Juliane; Strunk, Dirk; Schallmoser, Katharina; Volk, Hans-Dieter; Seifert, Martina

2017-05-01

Regeneration of injured tissues requires effective therapeutic strategies supporting vasculogenesis. The lack of instantly available autologous cell sources and immunogenicity of allogeneic endothelial (progenitor) cells limits clinical progress. Based on the immunosuppressive potency of mesenchymal stem/progenitor cells (MSCs), we investigated whether crosstalk between endothelial colony-forming progenitor cells (ECFCs) and MSCs during vasculogenesis could lower allogeneic T cell responses against ECFCs allowing long-term engraftment in vivo. Immunodeficient mice received subcutaneous grafts containing human ECFCs alone, or pairs of human ECFCs/MSCs from the same umbilical cord (UC) to study vasculogenesis in the presence of human leukocyte antigen (HLA)-mismatched human peripheral blood mononuclear cells (PBMCs). In vitro, cell surface marker changes due to interferon gamma (IFNγ) stimulation during ECFC/MSC coculture were determined and further effects on allostimulated T cell proliferation and cytotoxic lysis were measured. IFNγ-induced HLA-DR expression on ECFCs and MSCs, but both cell types had significantly less HLA-DR in cocultures. ECFC-induced T cell proliferation was abolished after MSC coculture as a result of HLA-DR downregulation and indolamin-2,3-dioxygenase activation. Additionally, allospecific CD8 + T cell-mediated lysis of ECFCs was reduced in cocultures. ECFC/MSC coapplication in immunodeficient mice not only promoted the generation of improved blood vessel architecture after 6 weeks, but also reduced intragraft immune cell infiltration and endothelial HLA-DR expression following PBMC reconstitution. Crosstalk between UC-derived ECFCs and MSCs after combined transplantation can lower the risk of ECFC rejection, thus enabling their coapplication for therapeutic vasculogenesis. Stem Cells 2017;35:1233-1245. © 2017 AlphaMed Press.

c-Fms signaling mediates neurofibromatosis Type-1 osteoclast gain-in-functions.

Directory of Open Access Journals (Sweden)

Yongzheng He

Full Text Available Skeletal abnormalities including osteoporosis and osteopenia occur frequently in both pediatric and adult neurofibromatosis type 1 (NF1 patients. NF1 (Nf1 haploinsufficient osteoclasts and osteoclast progenitors derived from both NF1 patients and Nf1(+/- mice exhibit increased differentiation, migration, and bone resorptive capacity in vitro, mediated by hyperactivation of p21(Ras in response to limiting concentrations of macrophage-colony stimulating factor (M-CSF. Here, we show that M-CSF binding to its receptor, c-Fms, results in increased c-Fms activation in Nf1(+/ (- osteoclast progenitors, mediating multiple gain-in-functions through the downstream effectors Erk1/2 and p90RSK. PLX3397, a potent and selective c-Fms inhibitor, attenuated M-CSF mediated Nf1(+/- osteoclast migration by 50%, adhesion by 70%, and pit formation by 60%. In vivo, we administered PLX3397 to Nf1(+/- osteoporotic mice induced by ovariectomy (OVX and evaluated changes in bone mass and skeletal architecture. We found that PLX3397 prevented bone loss in Nf1(+/--OVX mice by reducing osteoclast differentiation and bone resorptive activity in vivo. Collectively, these results implicate the M-CSF/c-Fms signaling axis as a critical pathway underlying the aberrant functioning of Nf1 haploinsufficient osteoclasts and may provide a potential therapeutic target for treating NF1 associated osteoporosis and osteopenia.

Chronic renal failure due to unilateral renal agenesis and total renal dysplasia (=aplasia)

International Nuclear Information System (INIS)

Kroepelin, T.; Ziupa, J.; Wimmer, B.

1983-01-01

Three adult patients with unilateral renal agenesis/total dysplasia (= aplasia) and with an early chronic renal failure are presented. One patient had renal agenesis without ureter bud and ureteric ostium on one side, and reflux pyelonephritis on the other; one had small compact total renal dysplasia (= aplasia) on one side, while chronic uric acid nephropathy (chronic renal disease as a cause of gout) was diagnosed on the other; the third patient had a total large multicystic dysplasia on one side, and on the other a segmental large multicystic dysplasia. Radiological steps and radiodiagnostic criteria are discussed and the combination of urogenital and extraurogenital anomalies is referred to. (orig.)

Efficacy of ultrasonography-guided renal biopsy for the evaluation of renal dysfunction following renal transplantation

International Nuclear Information System (INIS)

Kim, Young Jae; Choi, Chul Soon; Min, Seon Jeong; Lee, Gyung Kyu; Lee, Eil Seong; Kang, Ik Won; Bae, Sang Hoon

2003-01-01

To evaluate the usefulness and complications of renal biopsy under ultrasonography-guidance in renal dysfunction after renal transplantation. Ultrasonography-guided renal biopsy was done in 47 patients with the transplanted kidney. The subjects consisted of 30 males and 17 females, age ranged from 16 to 66 years (average age=38 years). Biopsies were done once in 27 patients, twice in 17 patients, three times in 3 patients, a total of 70 biopsies. The success rate of renal biopsy for the accurate pathologic diagnosis and the incidence and types of complications following biopsy were evaluated. The success rate of renal biopsy for the accurate pathologic diagnosis was 96%(67/70). Pathologic diagnosis included 27 cases of acute rejection (39%), 8 cases of acute tubular necrosis (11%), 4 cases of acute rejection and acute tubular necrosis (6%), 4 cases of cyclosporin toxicity (6%), 4 cases of primary disease recurrence (6%), 4 cases of infection (6%) and others. Complications after renal biopsy included 15 cases of microscopic hematuria (21%), 1 case of gross hematuria with spontaneous cessation and 1 case of life threatening hemorrhage. Ultrasonography-guided renal biopsy is a safe and effective diagnostic method for the evaluation of renal dysfunction following renal transplantation.

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Polyploidy and Mitotic Cell Death Are Two Distinct HIV-1 Vpr-Driven Outcomes in Renal Tubule Epithelial Cells.

Science.gov (United States)

Payne, Emily H; Ramalingam, Dhivya; Fox, Donald T; Klotman, Mary E

2018-01-15

Prior studies have found that HIV, through the Vpr protein, promotes genome reduplication (polyploidy) in infection-surviving epithelial cells within renal tissue. However, the temporal progression and molecular regulation through which Vpr promotes polyploidy have remained unclear. Here we define a sequential progression to Vpr-mediated polyploidy in human renal tubule epithelial cells (RTECs). We found that as in many cell types, Vpr first initiates G 2 cell cycle arrest in RTECs. We then identified a previously unreported cascade of Vpr-dependent events that lead to renal cell survival and polyploidy. Specifically, we found that a fraction of G 2 -arrested RTECs reenter the cell cycle. Following this cell cycle reentry, two distinct outcomes occur. Cells that enter complete mitosis undergo mitotic cell death due to extra centrosomes and aberrant division. Conversely, cells that abort mitosis undergo endoreplication to become polyploid. We further show that multiple small-molecule inhibitors of the phosphatidylinositol 3-kinase-related kinase (PIKK) family, including those that target ATR, ATM, and mTOR, indirectly prevent Vpr-mediated polyploidy by preventing G 2 arrest. In contrast, an inhibitor that targets DNA-dependent protein kinase (DNA-PK) specifically blocks the Vpr-mediated transition from G 2 arrest to polyploidy. These findings outline a temporal, molecularly regulated path to polyploidy in HIV-positive renal cells. IMPORTANCE Current cure-focused efforts in HIV research aim to elucidate the mechanisms of long-term persistence of HIV in compartments. The kidney is recognized as one such compartment, since viral DNA and mRNA persist in the renal tissues of HIV-positive patients. Further, renal disease is a long-term comorbidity in the setting of HIV. Thus, understanding the regulation and impact of HIV infection on renal cell biology will provide important insights into this unique HIV compartment. Our work identifies mechanisms that distinguish

Adaptive remodeling of the biliary tree: the essence of liver progenitor cell expansion.

Science.gov (United States)

Kok, Cindy Yuet-Yin; Miyajima, Atsushi; Itoh, Tohru

2015-07-01

The liver progenitor cell population has long been thought to exist within the liver. However, there are no standardized criteria for defining the liver progenitor cells, and there has been intense debate about the origin of these cells in the adult liver. The characteristics of such cells vary depending on the disease model used and also on the method of analysis. Visualization of three-dimensional biliary structures has revealed that the emergence of liver progenitor cells essentially reflects the adaptive remodeling of the hepatic biliary network in response to liver injury. We propose that the progenitor cell exists as a subpopulation in the biliary tree and show that the appearance of liver progenitor cells in injured parenchyma is reflective of extensive remodeling of the biliary structure. © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Localisation and mechanism of renal retention of radiolabelled somatostatin analogues

Energy Technology Data Exchange (ETDEWEB)

Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Barone, Raffaella [UCL, Centre of Nuclear Medicine and Laboratory of PET, Brussels (Belgium); Visser, Theo J. [Erasmus MC, Department of Internal Medicine, Rotterdam (Netherlands)

2005-10-01

Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scintigraphy and radionuclide therapy. The kidney is the most important critical organ during such therapy owing to the reabsorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake after intravenous injection of radiolabelled somatostatin analogues. The multi-ligand megalin/cubilin receptor complex, responsible for reabsorption of many peptides and proteins in the kidney, is an interesting candidate for renal endocytosis of these peptide analogues. For localisation studies, ex vivo autoradiography and micro-autoradiography of rat kidneys were performed 1-24 h after injection of radiolabelled somatostatin analogues and compared with the renal anti-megalin immunohistochemical staining pattern. To confirm a role of megalin in the mechanism of renal retention of [{sup 111}In-DTPA]octreotide, the effects of three inhibitory substances were explored in rats. Renal ex vivo autoradiography showed high cortical radioactivity and lower radioactivity in the outer medulla. The distribution of cortical radioactivity was inhomogeneous. Micro-autoradiography indicated that radioactivity was only retained in the proximal tubules. The anti-megalin immunohistochemical staining pattern showed a strong similarity with the renal [{sup 111}In-DTPA]octreotide ex vivo autoradiograms. Biodistribution studies showed that co-injection of positively charged d-lysine reduced renal uptake to 60% of control. Sodium maleate reduced renal [{sup 111}In-DTPA]octreotide uptake to 15% of control. Finally, cisplatin pre-treatment of rats reduced kidney uptake to 70% of control. Renal retention of [{sup 111}In-DTPA]octreotide is confined to proximal tubules in the rat kidney, in which megalin-mediated endocytosis may play an important part. (orig.)

Renal cell apoptosis in human lupus nephritis: a histological study

DEFF Research Database (Denmark)

Faurschou, M; Penkowa, Milena; Andersen, C B

2009-01-01

Nuclear autoantigens from apoptotic cells are believed to drive the immunological response in systemic lupus erythematosus (SLE). Conflicting data exist as to the possible renal origin of apoptotic cells in SLE patients with nephritis. We assessed the level of renal cell apoptosis in kidney...... biopsies from 35 patients with lupus nephritis by means of terminal deoxynucleotidyl-transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-digoxigenin nick end labeling (TUNEL). Five samples of normal kidney tissue served as control specimens. We did not observe apoptotic glomerular cells in any...... cells constitute a quantitatively important source of auto-antibody-inducing nuclear auto-antigens in human lupus nephritis....

The Progenitors of Local Ultra-massive Galaxies Across Cosmic Time

DEFF Research Database (Denmark)

Marchesini, Danilo; Muzzin, Adam; Stefanon, Mauro

2014-01-01

in age of $z=0$ UMGs as derived from their fossil records. The progenitors of local UMGs, including the star-forming ones, never lived on the blue cloud since $z=3$. We propose an alternative path for the formation of local UMGs that refines previously proposed pictures and that is fully consistent......-forming galaxies progressively increases, with the progenitors at $2z 1$, whereas the remaining was assembled via merging from $z\\sim 1$ to the present. Most of the quenching of the star-forming progenitors happened between $z=2.75$ and $z=1.25$, in good agreement with the typical formation redshift and scatter...

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Bone marrow niche-inspired, multiphase expansion of megakaryocytic progenitors with high polyploidization potential.

Science.gov (United States)

Panuganti, Swapna; Papoutsakis, Eleftherios T; Miller, William M

2010-10-01

Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo) and all combinations of Interleukin (IL)-3, IL-6, IL-11 and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide (NIC) to enhance polyploidization. Using Tpo + SCF + IL-3 + IL-11, we obtained 3.5 CD34+ CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2 /pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. NIC more than doubled the percentage of high-ploidy Mks to 40%. We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed NIC addition will greatly increase high-ploidy Mk production.

Low functional programming of renal AT2R mediates the developmental origin of glomerulosclerosis in adult offspring induced by prenatal caffeine exposure.

Science.gov (United States)

Ao, Ying; Sun, Zhaoxia; Hu, Shuangshuang; Zuo, Na; Li, Bin; Yang, Shuailong; Xia, Liping; Wu, Yong; Wang, Linlong; He, Zheng; Wang, Hui

2015-09-01

Our previous study has indicated that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR) of offspring. Recent research suggested that IUGR is a risk factor for glomerulosclerosis. However, whether PCE could induce glomerulosclerosis and its underlying mechanisms remain unknown. This study aimed to demonstrate the induction to glomerulosclerosis in adult offspring by PCE and its intrauterine programming mechanisms. A rat model of IUGR was established by PCE, male fetuses and adult offspring at the age of postnatal week 24 were euthanized. The results revealed that the adult offspring kidneys in the PCE group exhibited glomerulosclerosis as well as interstitial fibrosis, accompanied by elevated levels of serum creatinine and urine protein. Renal angiotensin II receptor type 2 (AT2R) gene expression in adult offspring was reduced by PCE, whereas the renal angiotensin II receptor type 1a (AT1aR)/AT2R expression ratio was increased. The fetal kidneys in the PCE group displayed an enlarged Bowman's space and a shrunken glomerular tuft, accompanied by a reduced cortex width and an increase in the nephrogenic zone/cortical zone ratio. Observation by electronic microscope revealed structural damage of podocytes; the reduced expression level of podocyte marker genes, nephrin and podocin, was also detected by q-PCR. Moreover, AT2R gene and protein expressions in fetal kidneys were inhibited by PCE, associated with the repression of the gene expression of glial-cell-line-derived neurotrophic factor (GDNF)/tyrosine kinase receptor (c-Ret) signaling pathway. These results demonstrated that PCE could induce dysplasia of fetal kidneys as well as glomerulosclerosis of adult offspring, and the low functional programming of renal AT2R might mediate the developmental origin of adult glomerulosclerosis. Copyright © 2015. Published by Elsevier Inc.

Nutrient-Deprived Retinal Progenitors Proliferate in Response to Hypoxia: Interaction of the HIF-1 and mTOR Pathway

Directory of Open Access Journals (Sweden)

Helena Khaliullina

2016-05-01

Full Text Available At a cellular level, nutrients are sensed by the mechanistic Target of Rapamycin (mTOR. The response of cells to hypoxia is regulated via action of the oxygen sensor Hypoxia-Inducible Factor 1 (HIF-1. During development, injury and disease, tissues might face conditions of both low nutrient supply and low oxygen, yet it is not clear how cells adapt to both nutrient restriction and hypoxia, or how mTOR and HIF-1 interact in such conditions. Here we explore this question in vivo with respect to cell proliferation using the ciliary marginal zone (CMZ of Xenopus. We found that both nutrient-deprivation and hypoxia cause retinal progenitors to decrease their proliferation, yet when nutrient-deprived progenitors are exposed to hypoxia there is an unexpected rise in cell proliferation. This increase, mediated by HIF-1 signalling, is dependent on glutaminolysis and reactivation of the mTOR pathway. We discuss how these findings in non-transformed tissue may also shed light on the ability of cancer cells in poorly vascularised solid tumours to proliferate.

Human mammary progenitor cell fate decisions are products of interactions with combinatorial microenvironments

Energy Technology Data Exchange (ETDEWEB)

LaBarge, Mark A; Nelson, Celeste M; Villadsen, Rene; Fridriksdottir, Agla; Ruth, Jason R; Stampfer, Martha R; Petersen, Ole W; Bissell, Mina J

2008-09-19

In adult tissues, multi-potent progenitor cells are some of the most primitive members of the developmental hierarchies that maintain homeostasis. That progenitors and their more mature progeny share identical genomes, suggests that fate decisions are directed by interactions with extrinsic soluble factors, ECM, and other cells, as well as physical properties of the ECM. To understand regulation of fate decisions, therefore, would require a means of understanding carefully choreographed combinatorial interactions. Here we used microenvironment protein microarrays to functionally identify combinations of cell-extrinsic mammary gland proteins and ECM molecules that imposed specific cell fates on bipotent human mammary progenitor cells. Micropatterned cell culture surfaces were fabricated to distinguish between the instructive effects of cell-cell versus cell-ECM interactions, as well as constellations of signaling molecules; and these were used in conjunction with physiologically relevant 3 dimensional human breast cultures. Both immortalized and primary human breast progenitors were analyzed. We report on the functional ability of those proteins of the mammary gland that maintain quiescence, maintain the progenitor state, and guide progenitor differentiation towards myoepithelial and luminal lineages.

Single progenitor model for GW150914 and GW170104

Science.gov (United States)

D'Orazio, Daniel J.; Loeb, Abraham

2018-04-01

The merger of stellar-mass black holes (BHs) is not expected to generate detectable electromagnetic (EM) emission. However, the gravitational wave (GW) events GW150914 and GW170104, detected by the Laser Interferometer Gravitational Wave Observatory to be the result of merging, ˜60 M⊙ binary black holes (BBHs), each have claimed coincident gamma-ray emission. Motivated by the intriguing possibility of an EM counterpart to BBH mergers, we construct a model that can reproduce the observed EM and GW signals for GW150914- and GW170104-like events, from a single-star progenitor. Following Loeb [Astrophys. J. Lett. 819, L21 (2016), 10.3847/2041-8205/819/2/L21], we envision a massive, rapidly rotating star within which a rotating-bar instability fractures the core into two overdensities that fragment into clumps which merge to form BHs in a tight binary with arbitrary spin-orbit alignment. Once formed, the BBH inspirals due to gas and gravitational-wave drag until tidal forces trigger strong feeding of the BHs with the surrounding stellar-density gas about 10 sec before merger. The resulting giga-Eddington accretion peak launches a jet that breaks out of the progenitor star and drives a powerful outflow that clears the gas from the orbit of the binary within 1 sec, preserving the vacuum GW waveform in the Laser Interferometer Gravitational Wave Observatory band. The single-progenitor scenario predicts the existence of variability of the gamma-ray burst, modulated at the ˜0.2 sec chirping period of the BBH due to relativistic Doppler boost. The jet breakout should be accompanied by a low-luminosity supernova. Finally, because the BBHs of the single-progenitor model do not exist at large separations, they will not be detectable in the low-frequency gravitational-wave band of the Laser Interferometer Space Antenna. Hence, the single-progenitor BBHs will be unambiguously discernible from BBHs formed through alternate, double-progenitor evolution scenarios.

PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

2012-05-01

Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

“Transcollateral” Renal Angioplasty for a Completely Occluded Renal Artery

International Nuclear Information System (INIS)

Chandra, Subash; Chadha, Davinder S.; Swamy, Ajay

2011-01-01

Percutaneous transluminal renal angioplasty with stenting has been effective in the control of hypertension, renal function, and pulmonary edema caused by atherosclerotic renal artery stenosis. However, the role of the procedure has not been fully established in the context of chronic total occlusion of renal artery. We report the successful use of this procedure in 57-year-old male patient who reported for evaluation of a recent episode of accelerated hypertension. A renal angiogram in this patient showed ostial stenosis of the right renal artery, which was filling by way of the collateral artery. Renal angioplasty for chronic total occlusion of right renal artery was successfully performed in a retrograde fashion through a collateral artery, thereby leading to improvement of renal function and blood pressure control.

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The exercise renogram. A new approach documents renal involvement in systemic hypertension

International Nuclear Information System (INIS)

Clorius, J.H.; Schmidlin, P.

1983-01-01

Hippurate functional scintiscans were obtained in 51 hypertensive patients and in 15 controls. We investigated the influence that posture and exercise have on hippurate kinetics in patients with hypertension. A posture- or exercise-induced disturbance of renal hippurate transport was sought. All persons were examined in prone and standing positions, as well as during exercise. When prone and upright renograms were compared, 24% of the hypertensives demonstrated bilateral orthostatic renal dysfunction. Exercise caused the hippurate transport disturbance to increase. Fifty-seven percent of all hypertensives developed evidence of marked, bilateral, renal dysfunction during ergometric stress, so that exercise renography was shown to be a more sensitive test of the presence of transient tubular dysfunction in hypertension than the standing renogram. In normotensive controls the hippurate functional scintigram failed to be influenced by posture and exercise. The results suggest presence in hypertension of transient, posture- and exercise-mediated alterations of renal cortical blood flow

Allopurinol attenuates rhabdomyolysis-associated acute kidney injury: Renal and muscular protection.

Science.gov (United States)

Gois, Pedro H F; Canale, Daniele; Volpini, Rildo A; Ferreira, Daniela; Veras, Mariana M; Andrade-Oliveira, Vinicius; Câmara, Niels O S; Shimizu, Maria H M; Seguro, Antonio C

2016-12-01

Acute kidney injury (AKI) is the most severe complication of rhabdomyolysis. Allopurinol (Allo), a xanthine oxidase inhibitor, has been in the spotlight in the last decade due to new therapeutic applications related to its potent antioxidant effect. The aim of this study was to evaluate the efficacy of Allo in the prevention and treatment of rhabdomyolysis-associated AKI. Male Wistar rats were divided into five groups: saline control group; prophylactic Allo (300mg/L of drinking water, 7 days); glycerol (50%, 5ml/kg, IM); prophylactic Allo + glycerol; and therapeutic Allo (50mg/Kg, IV, 30min after glycerol injection) + glycerol. Glycerol-injected rats showed markedly reduced glomerular filtration rate associated with renal vasoconstriction, renal tubular damage, increased oxidative stress, apoptosis and inflammation. Allo ameliorated all these alterations. We found 8-isoprostane-PGF 2a (F2-IsoP) as a main factor involved in the oxidative stress-mediated renal vasoconstriction following rhabdomyolysis. Allo reduced F2-IsoP renal expression and restored renal blood flow. Allo also reduced oxidative stress in the damaged muscle, attenuated muscle lesion/inflammation and accelerated muscular recovery. Moreover, we showed new insights into the pathogenesis of rhabdomyolysis-associated AKI, whereas Allo treatment reduced renal inflammation by decreasing renal tissue uric acid levels and consequently inhibiting the inflammasome cascade. Allo treatment attenuates renal dysfunction in a model of rhabdomyolysis-associated AKI by reducing oxidative stress (systemic, renal and muscular), apoptosis and inflammation. This may represent a new therapeutic approach for rhabdomyolysis-associated AKI - a new use for an old and widely available medication. Copyright © 2016 Elsevier Inc. All rights reserved.

PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud.

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Norrie, Jacqueline L; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T; Galli, Antonella; Ji, Hongkai; Vokes, Steven A

2016-12-15

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4 Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. © 2016. Published by The Company of Biologists Ltd.

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Induction of osteoblast differentiation by selective activation of kinase-mediated actions of the estrogen receptor.

Science.gov (United States)

Kousteni, Stavroula; Almeida, Maria; Han, Li; Bellido, Teresita; Jilka, Robert L; Manolagas, Stavros C

2007-02-01

Estrogens control gene transcription by cis or trans interactions of the estrogen receptor (ER) with target DNA or via the activation of cytoplasmic kinases. We report that selective activation of kinase-mediated actions of the ER with 4-estren-3alpha,17beta-diol (estren) or an estradiol-dendrimer conjugate, each a synthetic compound that stimulates kinase-mediated ER actions 1,000 to 10,000 times more potently than direct DNA interactions, induced osteoblastic differentiation in established cell lines of uncommitted osteoblast precursors and primary cultures of osteoblast progenitors by stimulating Wnt and BMP-2 signaling in a kinase-dependent manner. In sharp contrast, 17beta-estradiol (E(2)) suppressed BMP-2-induced osteoblast progenitor commitment and differentiation. Consistent with the in vitro findings, estren, but not E(2), stimulated Wnt/beta-catenin-mediated transcription in T-cell factor-lacZ transgenic mice. Moreover, E(2) stimulated BMP signaling in mice in which ERalpha lacks DNA binding activity and classical estrogen response element-mediated transcription (ERalpha(NERKI/-)) but not in wild-type controls. This evidence reveals for the first time the existence of a large signalosome in which inputs from the ER, kinases, bone morphogenetic proteins, and Wnt signaling converge to induce differentiation of osteoblast precursors. ER can either induce it or repress it, depending on whether the activating ligand (and presumably the resulting conformation of the receptor protein) precludes or accommodates ERE-mediated transcription.

Lung Regeneration: Endogenous and Exogenous Stem Cell Mediated Therapeutic Approaches.

Science.gov (United States)

Akram, Khondoker M; Patel, Neil; Spiteri, Monica A; Forsyth, Nicholas R

2016-01-19

The tissue turnover of unperturbed adult lung is remarkably slow. However, after injury or insult, a specialised group of facultative lung progenitors become activated to replenish damaged tissue through a reparative process called regeneration. Disruption in this process results in healing by fibrosis causing aberrant lung remodelling and organ dysfunction. Post-insult failure of regeneration leads to various incurable lung diseases including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Therefore, identification of true endogenous lung progenitors/stem cells, and their regenerative pathway are crucial for next-generation therapeutic development. Recent studies provide exciting and novel insights into postnatal lung development and post-injury lung regeneration by native lung progenitors. Furthermore, exogenous application of bone marrow stem cells, embryonic stem cells and inducible pluripotent stem cells (iPSC) show evidences of their regenerative capacity in the repair of injured and diseased lungs. With the advent of modern tissue engineering techniques, whole lung regeneration in the lab using de-cellularised tissue scaffold and stem cells is now becoming reality. In this review, we will highlight the advancement of our understanding in lung regeneration and development of stem cell mediated therapeutic strategies in combating incurable lung diseases.

Human Articular Cartilage Progenitor Cells Are Responsive to Mechanical Stimulation and Adenoviral-Mediated Overexpression of Bone-Morphogenetic Protein 2.

Directory of Open Access Journals (Sweden)

Alexander J Neumann

Full Text Available Articular cartilage progenitor cells (ACPCs represent a new and potentially powerful alternative cell source to commonly used cell sources for cartilage repair, such as chondrocytes and bone-marrow derived mesenchymal stem cells (MSCs. This is particularly due to the apparent resistance of ACPCs to hypertrophy. The current study opted to investigate whether human ACPCs (hACPCs are responsive towards mechanical stimulation and/or adenoviral-mediated overexpression of bone morphogenetic protein 2 (BMP-2. hACPCs were cultured in fibrin-polyurethane composite scaffolds. Cells were cultured in a defined chondro-permissive medium, lacking exogenous growth factors. Constructs were cultured, for 7 or 28 days, under free-swelling conditions or with the application of complex mechanical stimulation, using a custom built bioreactor that is able to generate joint-like movements. Outcome parameters were quantification of BMP-2 and transforming growth factor beta 1 (TGF-β1 concentration within the cell culture medium, biochemical and gene expression analyses, histology and immunohistochemistry. The application of mechanical stimulation alone resulted in the initiation of chondrogenesis, demonstrating the cells are mechanoresponsive. This was evidenced by increased GAG production, lack of expression of hypertrophic markers and a promising gene expression profile (significant up-regulation of cartilaginous marker genes, specifically collagen type II, accompanied by no increase in the hypertrophic marker collagen type X or the osteogenic marker alkaline phosphatase. To further investigate the resistance of ACPCs to hypertrophy, overexpression of a factor associated with hypertrophic differentiation, BMP-2, was investigated. A novel, three-dimensional, transduction protocol was used to transduce cells with an adenovirus coding for BMP-2. Over-expression of BMP-2, independent of load, led to an increase in markers associated with hypertropy. Taken together ACPCs

Influences of renal stone surgeries on renal function; Evaluation of renal function with sup 99m Tc-DMSA renal scintigraphy

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Katayama, Yasushi (Niigata Univ. (Japan). School of Medicine)

1991-10-01

From 1984 to 1990, {sup 99m}Tc-DMSA renal scintigraphy was performed before and after nephrolithotomy (15 cases), pyelolithotomy (15 cases), percutaneous nephrolithotripsy (PNL: 15 cases) and extracorporeal shock wave lithotripsy (ESWL: 16 cases, 17 kidneys) in order to evaluate of influences of renal stone surgeries on split renal function. DMSA renal uptake change ratio of treated kidneys of nephrolithotomy (-24.94{+-}5.60%) was significantly lower than that of PNL (-0.06{+-}3.92%), pyelolithotomy (-4.08{+-}4.79%) (p<0.01) and ESWL (-7.72{+-}3.87%) (p<0.05). The average change ratios of contralateral kidneys were as follows: PNL 4.80{+-}4.21% nephrolithotomy 4.67{+-}4.73%, pyelolithotomy -1.46{+-}5.39% and ESWL -2.02{+-}4.44%. One to 3 weeks after PNL, the cold area on the renal image was found in 10 (66.7%) of 15 cases. In cases of ESWL, DMSA renal uptake decreased even 4-10 weeks (mean 7 weeks) after treatment. In conclusion, possibility of deterioration of renal function after ESWL was suggested. (author).

Intersections of lung progenitor cells, lung disease and lung cancer.

Science.gov (United States)

Kim, Carla F

2017-06-30

The use of stem cell biology approaches to study adult lung progenitor cells and lung cancer has brought a variety of new techniques to the field of lung biology and has elucidated new pathways that may be therapeutic targets in lung cancer. Recent results have begun to identify the ways in which different cell populations interact to regulate progenitor activity, and this has implications for the interventions that are possible in cancer and in a variety of lung diseases. Today's better understanding of the mechanisms that regulate lung progenitor cell self-renewal and differentiation, including understanding how multiple epigenetic factors affect lung injury repair, holds the promise for future better treatments for lung cancer and for optimising the response to therapy in lung cancer. Working between platforms in sophisticated organoid culture techniques, genetically engineered mouse models of injury and cancer, and human cell lines and specimens, lung progenitor cell studies can begin with basic biology, progress to translational research and finally lead to the beginnings of clinical trials. Copyright ©ERS 2017.

Intersections of lung progenitor cells, lung disease and lung cancer

Directory of Open Access Journals (Sweden)

Carla F. Kim

2017-06-01

Full Text Available The use of stem cell biology approaches to study adult lung progenitor cells and lung cancer has brought a variety of new techniques to the field of lung biology and has elucidated new pathways that may be therapeutic targets in lung cancer. Recent results have begun to identify the ways in which different cell populations interact to regulate progenitor activity, and this has implications for the interventions that are possible in cancer and in a variety of lung diseases. Today's better understanding of the mechanisms that regulate lung progenitor cell self-renewal and differentiation, including understanding how multiple epigenetic factors affect lung injury repair, holds the promise for future better treatments for lung cancer and for optimising the response to therapy in lung cancer. Working between platforms in sophisticated organoid culture techniques, genetically engineered mouse models of injury and cancer, and human cell lines and specimens, lung progenitor cell studies can begin with basic biology, progress to translational research and finally lead to the beginnings of clinical trials.

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Renal Osteodystrophy

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Aynur Metin Terzibaşoğlu

2004-12-01

Full Text Available Chronic renal insufficiency is a functional definition which is characterized by irreversible and progressive decreasing in renal functions. This impairment is in collaboration with glomeruler filtration rate and serum creatinine levels. Besides this, different grades of bone metabolism disorders develop in chronic renal insufficiency. Pathologic changes in bone tissue due to loss of renal paranchyme is interrelated with calcium, phosphorus vitamine-D and parathyroid hormone. Clinically we can see high turnover bone disease, low turnover bone disease, osteomalacia, osteosclerosis and osteoporosis in renal osteodystropy. In this article we aimed to review pathology of bone metabolism disorders due to chronic renal insufficiency, clinic aspects and treatment approaches briefly.

In vitro comparison of renal handling and uptake of two somatostatin receptor-specific peptides labeled with indium-111

International Nuclear Information System (INIS)

Trejtnar, F.; Novy, Z.; Petrik, M.; Laznickova, A.; Melicharova, L.; Vankova, M.; Laznicek, M.

2008-01-01

Radiolabeled receptor-specific somatostatin analogs labeled with gamma- or beta-emitting radionuclides are useful for scintigraphic imaging and/or therapy of selected neuroendocrine tumors. However, significant renal uptake may result in radiotoxicological injury of the kidney and can limit clinical application of the agents. The aim of the study was to analyze renal handling, rate, and mechanism of renal accumulation of two somatostatin receptor-targeted peptides, [DOTA 0 , Tyr 3 , Thr 8 ]-octreotide (DOTA-TATE) and [DOTA 0 , 1-Nal 3 ]-octreotide (DOTA-NOC), labeled with indium-111 using in vitro methods. The perfused rat kidney and freshly isolated rat renal cells were used as experimental models. The perfusion was performed in a recirculation regimen at constant pressure with solution containing bovine albumin, erythrocytes, and a mixture of essential substrates. The renal cells were isolated from rat kidneys using two-phase collagenase perfusion. Accumulation studies were used to evaluate the renal uptake of the peptides and to compare their accumulation with that of passively or actively transported model drugs. The influence of selected inhibitors of receptor-mediated endocytosis and the inhibition of energy-dependent transport processes on the uptake were also investigated using isolated renal cells. The renal clearance of 111 In-DOTA-NOC in the perfused rat kidney was significantly lower than that of 111 In-DOTA-TATE. Reverse situation was found in the case of renal retention. Pretreatment of the perfused kidney with maleate markedly decreased the renal retention. 111 In-DOTA-NOC was accumulated in the isolated renal cells at a higher rate than 111 In-DOTA-TATE (ratio 3:1). The uptake of the radiopeptides in renal cells was higher than the uptake of not only the passively transported sucrose but also actively transported and accumulated methylglucose. The rank order of potency to inhibit the uptake by active endocytosis was approximately aprotinin

Multidrug Resistance Proteins and the Renal Elimination of Inorganic Mercury Mediated by 2,3-Dimercaptopropane-1-Sulfonic Acid and Meso-2,3-dimercaptosuccinic Acid

Science.gov (United States)

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

2008-01-01

Current therapies for inorganic mercury (Hg2+) intoxication include administration of a metal chelator, either 2,3-dimercaptopropane-1-sulfonic acid (DMPS) or meso-2,3-dimercaptosuccinic acid (DMSA). After exposure to either chelator, Hg2+ is rapidly eliminated from the kidneys and excreted in the urine, presumably as an S-conjugate of DMPS or DMSA. The multidrug resistance protein 2 (Mrp2) has been implicated in this process. We hypothesize that Mrp2 mediates the secretion of DMPS- or DMSA-S-conjugates of Hg2+ from proximal tubular cells. To test this hypothesis, the disposition of Hg2+ was examined in control and Mrp2-deficient TR− rats. Rats were injected i.v. with 0.5 μmol/kg HgCl2 containing 203Hg2+. Twenty-four and 28 h later, rats were injected with saline, DMPS, or DMSA. Tissues were harvested 48 h after HgCl2 exposure. The renal and hepatic burden of Hg2+ in the saline-injected TR− rats was greater than that of controls. In contrast, the amount of Hg2+ excreted in urine and feces of TR− rats was less than that of controls. DMPS, but not DMSA, significantly reduced the renal and hepatic content of Hg2+ in both groups of rats, with the greatest reduction in controls. A significant increase in urinary and fecal excretion of Hg2+, which was greater in the controls, was also observed following DMPS treatment. Experiments utilizing inside-out membrane vesicles expressing MRP2 support these observations by demonstrating that DMPS- and DMSA-S-conjugates of Hg2+ are transportable substrates of MRP2. Collectively, these data support a role for Mrp2 in the DMPS- and DMSA-mediated elimination of Hg2+ from the kidney. PMID:17940195

Pulpal progenitors and dentin repair.

Science.gov (United States)

Harichane, Y; Hirata, A; Dimitrova-Nakov, S; Granja, I; Goldberg, A; Kellermann, O; Poliard, A

2011-07-01

Mesenchymal stem cells are present in the dental pulp. They have been shown to contribute to dentin-like tissue formation in vitro and to participate in bone repair after a mandibular lesion. However, their capacity to contribute efficiently to reparative dentin formation after pulp lesion has never been explored. After pulp exposure, we have identified proliferative cells within 3 zones. In the crown, zone I is near the cavity, and zone II corresponds to the isthmus between the mesial and central pulp. In the root, zone III, near the apex, at a distance from the inflammatory site, contains mitotic stromal cells which may represent a source of progenitor cells. Stem-cell-based strategies are promising treatments for tissue injury in dentistry. Our experiments focused on (1) location of stem cells induced to leave their quiescent state early after pulp injury and (2) implantation of pulp progenitors, a substitute for classic endodontic treatments, paving the way for pulp stem-cell-based therapies.

CT differentiation of infiltrating renal cell carcinoma and renal urothelial tumor

International Nuclear Information System (INIS)

Choi, Hyo Kyeong; Goo, Dong Erk; Bang, Sun Woo; Lee, Moon Gyu; Cho, Kyoung Sik; Auh, Yong Ho

1994-01-01

It may be difficult to differentiate renal cell carcinoma involving collecting system from renal urothelial tumor invading into renal parenchyma. The purpose of this study was to assess the differences of CT findings between two conditions. CT findings of 5 cases of renal cell carcinoma involving the renal collecting systems and 10 cases of renal urothelial tumors invading the renal parenchyma were compared, and analyzed about the presence or absence of hydronephrosis, normal or abnormal CT nephrogram, renal contour changes due to mass and tentative diagnosis. The diagnoses were confirmed at surgery. Renal cell carcinoma showed hydronephrosis in only 20% and normal CT nephrogram and outward contour bulging in all cases. In contrast, renal urothelial tumor showed hydronephrosis(70%), abnormal CT nephrogram(60%), and preservation of reinform shape(100%). Renal contour changes and CT nephrogram may be useful in distinguishing both disease entities

Regulated proliferation of primitive hematopoietic progenitor cells in long-term human marrow cultures

International Nuclear Information System (INIS)

Cashman, J.; Eaves, A.C.; Eaves, C.J.

1985-01-01

We have examined the cycling status of various classes of erythroid and granulopoietic progenitor populations maintained for many weeks in standard normal long-term human marrow cultures. These were initiated with a single inoculum of marrow aspirate and were routinely fed by weekly removal of half of the nonadherent cells and replacement of half of the growth medium. Progenitors of large erythroid colonies (more than eight erythroblast clusters) present in the nonadherent fraction and progenitors of small granulocyte/macrophage colonies (fewer than 500 cells) present in both the nonadherent and adherent fractions were found to be actively cycling at all times examined (28% to 63% kill following a 20-minute exposure to 20 microCi/mL of high specific activity 3 H-thymidine). In contrast, progenitors of large granulocyte/macrophage colonies (more than 500 cells) and progenitors of large erythroid colonies (more than eight erythroblast clusters), present in the adherent layer, consistently alternated between a quiescent state at the time of each weekly medium change and a proliferating state two to three days later (0% to 13% kill and 21% to 49% kill, respectively). Additional experiments revealed that the activation of primitive progenitors in the adherent layer was not dependent on the addition of fresh glutamine or hydrocortisone, nor on the physical manipulations involved in changing the growth medium. These studies provide the first direct evidence that normal long-term human marrow cultures support the continued turnover of a variety of early hematopoietic progenitor cell types. Further, they indicate that the proliferative activity of the most primitive of these progenitors is regulated by stage-specific cell-cell interactions that are subject to manipulation

Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

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Sheng, Lili; Yang, Min; Ding, Wei [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Zhang, Minmin [Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China); Niu, Jianying [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Qiao, Zhongdong [School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200240 (China); Gu, Yong, E-mail: yonggu@vip.163.com [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China)

2016-08-01

Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangial cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.

Tubular overexpression of gremlin induces renal damage susceptibility in mice.

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Alejandra Droguett

Full Text Available A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-β. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1 specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2- to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-β and αSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage

European Veterinary Renal Pathology Service: A Survey Over a 7-Year Period (2008-2015).

Science.gov (United States)

Aresu, L; Martini, V; Benali, S L; Brovida, C; Cianciolo, R E; Dalla Riva, R; Trez, D; Van Der Lugt, J J; Van Dongen, A; Zini, E

2017-09-01

The European Veterinary Renal Pathology Service (EVRPS) is the first Web-based registry for canine renal biopsy specimens in Europe. The aim was to verify whether differences exist between the clinical and laboratory presentation of dogs with nephropathy according to renal pathological findings, as defined by light and electron microscopy of renal biopsy specimens submitted to EVRPS. Renal biopsy specimens of dogs were collected from the archive of the service (n = 254). Cases were included if both light and electron microscopy were available (n = 162). Renal biopsy specimens were classified based on the morphological diagnoses. Thereafter, they were grouped into 3 disease categories, including immune-complex-mediated glomerulonephritis (ICGN), non-immune-complex-mediated GN (non-ICGN), and renal lesions not otherwise specified (RL-NOS). Differences among morphological diagnoses and among disease categories were investigated for clinical and laboratory variables. Serum albumin concentration was lower in dogs with ICGN than in those with non-ICGN (P = 0.006) or RL-NOS (P = 0.000), and the urine protein-to-creatinine ratio (UPC) was significantly higher in ICGN than in the other 2 disease categories. Regarding morphological diagnoses, albumin was significantly lower in amyloidosis (AMY) and membranous (MGN), membranoproliferative (MPGN) or mixed glomerulonephritis (MixGN) than in minimal change disease, primary (FSGS I) or secondary (FSGS II) focal and segmental glomerulosclerosis and juvenile nephropathies (JN). The UPC was higher in MPGN than in FSGS I and FSGS II. Dogs with ICGN, in particular MPGN, had higher protein loss than those with non-ICGN or RL-NOS, leading to more severe hypoalbuminemia. Clinical and laboratory differentiation among dogs with the different morphological diagnoses and among dogs with different disease categories was difficult due to overlapping results. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine

File list: InP.Neu.20.AllAg.Neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

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Lifescience Database Archive (English)

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File list: InP.Neu.05.AllAg.Neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

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The renal scan in pregnant renal transplant patients

International Nuclear Information System (INIS)

Goldstein, H.A.; Ziessman, H.A.; Fahey, F.H.; Collea, J.V.; Alijani, M.R.; Helfrich, G.B.

1985-01-01

With the greater frequency of renal transplant surgery, more female pts are becoming pregnant and carrying to term. In the renal allograft blood vessels and ureter may be compressed resulting in impaired renal function and/or, hypertension. Toxemia of pregnancy is seen more frequently than normal. Radionuclide renal scan monitoring may be of significant value in this high risk obstetrical pt. After being maintained during the pregnancy, renal function may also deteriorate in the post partum period. 5 pregnant renal transplant pts who delivered live babies had renal studies with Tc-99m DTPA to assess allograft perfusion and function. No transplanted kidney was lost during or after pregnancy as a result of pregnancy. No congenital anomalies were associated with transplant management. 7 studies were performed on these 5 pts. The 7 scans all showed the uterus/placenta. The bladder was always distorted. The transplanted kidney was rotated to a more vertical position in 3 pts. The radiation dose to the fetus is calculated at 0.024 rad/mCi administered. This study demonstrates the anatomic and physiologic alterations expected in the transplanted kidney during pregnancy when evaluated by renal scan and that the radiation burden may be acceptable in management of these pts

Ciglitazone induces caspase-independent apoptosis via p38-dependent AIF nuclear translocation in renal epithelial cells

International Nuclear Information System (INIS)

Kwon, Chae Hwa; Yoon, Chang Soo; Kim, Yong Keun

2008-01-01

Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been reported to induce apoptosis in a variety of cell types including renal proximal epithelial cells. However, the underlying mechanism of cell death induced by PPARγ agonists has not been clearly defined in renal proximal tubular cells. This study was therefore undertaken to determine the mechanism by which ciglitazone, a synthetic PPARγ agonist, induces apoptosis in opossum kidney (OK) cells, an established renal epithelial cell line. Ciglitazone treatment induced apoptotic cell death in a dose- and time-dependent manner. Ciglitazone caused a transient activation of ERK and sustained activation of p38 MAP kinase. Ciglitazone-mediated cell death was attenuated by the p38 inhibitor SB203580 and transfection of dominant-negative form of p38, but not by the MEK inhibitor U0126, indicating that p38 MAP kinase activation is involved in the ciglitazone-induced cell death. Although ciglitazone-induced caspase-3 activation, the ciglitazone-mediated cell death was not affected by the caspase-3 inhibitor DEVD-CHO. Ciglitazone-induced mitochondrial membrane depolarization and apoptosis-inducing factor (AIF) nuclear translocation and these effects were prevented by the p38 inhibitor. These results suggest that ciglitazone induces caspase-independent apoptosis through p38 MAP kinase-dependent AIF nuclear translocation in OK renal epithelial cells

Renal transplantation in Nepal: The first year′s experience

Directory of Open Access Journals (Sweden)

Chalise Pawan

2010-01-01

Full Text Available A successful renal transplantation service was started in Nepal at the Tribhuvan Univer-sity Teaching Hospital in August 2008, and a continuing regular service is being provided currently to needy people. We report here our experience in thirty five end stage renal disease patients who re-ceived kidneys from close relatives during a one year period. The mean age of donors was 46.7 years. Seventeen (49% donations were from parents, 13 (37% from spouses, four (11% between siblings and one (3% between mother and daughter in law. Although the left kidney was given preference, right sided donor nephrectomy was needed in five (14% cases. Six (17% donors had minor post-operative problems. The mean age of recipients was 33.2 years, four (11% of whom had pre-emptive renal transplantation. Recipients were immunosuppressed with dacluzimab, prednisolone, mycophena-late, and cyclosporine or tacrolimus. The average time taken for graft implantation was 137 minutes. The mean cold ischemia time and second warm ischemia time were 133 and 36 minutes respectively. Four (11% patients developed urinary tract infection, three (9% had significant hematuria, one (3% developed a peri-transplant abscess, and one (3% had ureteric ischemia and urine leak which required re-exploration in the early post-operative period. Four patients (11% developed acute rejection of which three were cell- mediated rejection and one was antibody-mediated. There were two (6% deaths, one due to transplant-related sepsis and the other due to subarachnoid hemorrhage following rupture of a posterior communicating artery aneurysm. No kidney has been lost otherwise.

Transplantation of Expanded Fetal Intestinal Progenitors Contributes to Colon Regeneration after Injury

DEFF Research Database (Denmark)

Fordham, Robert P; Yui, Shiro; Hannan, Nicholas R F

2013-01-01

Regeneration and homeostasis in the adult intestinal epithelium is driven by proliferative resident stem cells, whose functional properties during organismal development are largely unknown. Here, we show that human and mouse fetal intestine contains proliferative, immature progenitors, which can...... be expanded in vitro as Fetal Enterospheres (FEnS). A highly similar progenitor population can be established during intestinal differentiation of human induced pluripotent stem cells. Established cultures of mouse fetal intestinal progenitors express lower levels of Lgr5 than mature progenitors and propagate...... in the presence of the Wnt antagonist Dkk1, and new cultures can be induced to form mature intestinal organoids by exposure to Wnt3a. Following transplantation in a colonic injury model, FEnS contribute to regeneration of colonic epithelium by forming epithelial crypt-like structures expressing region...

Effects of hematopoietic growth factors on purified bone marrow progenitor cells

NARCIS (Netherlands)

F.J. Bot (Freek)

1992-01-01

textabstractWe have used highly enriched hematopoietic progenitor cells and in-vitro culture to examine the following questions: 1. The effects of recombinant lL-3 and GM-CSF on proliferation and differentiation of enriched hematopoietic progenitor cells have not been clearly defined: - how do IL~3

PLZF regulates fibroblast growth factor responsiveness and maintenance of neural progenitors.

Science.gov (United States)

Gaber, Zachary B; Butler, Samantha J; Novitch, Bennett G

2013-10-01

Distinct classes of neurons and glial cells in the developing spinal cord arise at specific times and in specific quantities from spatially discrete neural progenitor domains. Thus, adjacent domains can exhibit marked differences in their proliferative potential and timing of differentiation. However, remarkably little is known about the mechanisms that account for this regional control. Here, we show that the transcription factor Promyelocytic Leukemia Zinc Finger (PLZF) plays a critical role shaping patterns of neuronal differentiation by gating the expression of Fibroblast Growth Factor (FGF) Receptor 3 and responsiveness of progenitors to FGFs. PLZF elevation increases FGFR3 expression and STAT3 pathway activity, suppresses neurogenesis, and biases progenitors towards glial cell production. In contrast, PLZF loss reduces FGFR3 levels, leading to premature neuronal differentiation. Together, these findings reveal a novel transcriptional strategy for spatially tuning the responsiveness of distinct neural progenitor groups to broadly distributed mitogenic signals in the embryonic environment.

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.

Can pancreatic duct-derived progenitors be a source of islet regeneration?

International Nuclear Information System (INIS)

Xia, Bing; Zhan, Xiao-Rong; Yi, Ran; Yang, Baofeng

2009-01-01

The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing β-cells. The functional mass of β-cells is decreased in type 1 diabetes, so replacing missing β-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the β-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding β-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet β-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal cells as an in vivo progenitor for

Can pancreatic duct-derived progenitors be a source of islet regeneration?

Energy Technology Data Exchange (ETDEWEB)

Xia, Bing [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Zhan, Xiao-Rong, E-mail: xiaorongzhan@sina.com [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yi, Ran [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yang, Baofeng [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)

2009-06-12

The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing {beta}-cells. The functional mass of {beta}-cells is decreased in type 1 diabetes, so replacing missing {beta}-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the {beta}-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding {beta}-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet {beta}-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal

The Type IIb Supernova 2013df and its Cool Supergiant Progenitor

Science.gov (United States)

VanDyk, Schuyler D.; Zeng, Weikang; Fox, Ori D.; Cenko, S. Bradley; Clubb, Kelsey I.; Filippenko, Alexei; Foley, Ryan J.; Miller, Adam A.; Smith, Nathan; Kelly, Patrick L.;

The type IIb supernova 2013df and its cool supergiant progenitor

Energy Technology Data Exchange (ETDEWEB)

Van Dyk, Schuyler D. [Spitzer Science Center/Caltech, Mail Code 220-6, Pasadena, CA 91125 (United States); Zheng, WeiKang; Fox, Ori D.; Clubb, Kelsey I.; Filippenko, Alexei V.; Kelly, Patrick L. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Foley, Ryan J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Miller, Adam A. [Jet Propulsion Laboratory, MS 169-506, Pasadena, CA 91109 (United States); Smith, Nathan [Steward Observatory, University of Arizona, Tucson, AZ 85720 (United States); Lee, William H. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 70-264, Cd. Universitaria, México DF 04510 (Mexico); Ben-Ami, Sagi; Gal-Yam, Avishay, E-mail: vandyk@ipac.caltech.edu [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel)

2014-02-01

We have obtained early-time photometry and spectroscopy of supernova (SN) 2013df in NGC 4414. The SN is clearly of Type IIb, with notable similarities to SN 1993J. From its luminosity at secondary maximum light, it appears that less {sup 56}Ni (≲ 0.06 M {sub ☉}) was synthesized in the SN 2013df explosion than was the case for the SNe IIb 1993J, 2008ax, and 2011dh. Based on a comparison of the light curves, the SN 2013df progenitor must have been more extended in radius prior to explosion than the progenitor of SN 1993J. The total extinction for SN 2013df is estimated to be A{sub V} = 0.30 mag. The metallicity at the SN location is likely to be solar. We have conducted Hubble Space Telescope (HST) Target of Opportunity observations of the SN with the Wide Field Camera 3, and from a precise comparison of these new observations to archival HST observations of the host galaxy obtained 14 yr prior to explosion, we have identified the progenitor of SN 2013df to be a yellow supergiant, somewhat hotter than a red supergiant progenitor for a normal Type II-Plateau SN. From its observed spectral energy distribution, assuming that the light is dominated by one star, the progenitor had effective temperature T {sub eff} = 4250 ± 100 K and a bolometric luminosity L {sub bol} = 10{sup 4.94±0.06} L {sub ☉}. This leads to an effective radius R {sub eff} = 545 ± 65 R {sub ☉}. The star likely had an initial mass in the range of 13-17 M {sub ☉}; however, if it was a member of an interacting binary system, detailed modeling of the system is required to estimate this mass more accurately. The progenitor star of SN 2013df appears to have been relatively similar to the progenitor of SN 1993J.

Observational Investigations of the Progenitors of Supernovae

Science.gov (United States)

Lyman, J. D.

2014-03-01

Supernovae (SNe) are the spectacular deaths of stars and have shaped the universe we see today. Their far-reaching influence affects the chemical and dynamical evolution of galaxies, star formation, neutron star and black hole formation, and they are largely responsible for most of the heavy elements that make up the universe, including around 90 per cent of the reader. They also provide laboratories of nuclear and particle physics far beyond what we can construct on Earth and act as probes of extreme density and energy. This thesis presents new research into understanding the nature of the progenitor systems of various types of SNe, as well as presenting results that will allow their study to be more productive in the future, through use of automated pipelines and methods to increase the science value of discovered SNe. An environmental study of two peculiar types of transients ('Calcium-rich' and '2002cx-like'), which may not be true SNe, reveals extremely different ages of the exploding systems that will constrain the current theoretical effort into discovering the progenitor systems. The GRB-SN 120422A/2012bz is investigated and found to be an extremely luminous and energetic SN, even amongst the infamously bright GRB-SNe. A method is presented that allows an accurate reconstruction of the bolometric light curve of a core-collapse SN, which relies on only two optical filter observations - this will hugely reduce the observational cost of constructing bolometric light curves, a tool of great importance when hoping to constrain the nature of a SN explosion and hence its progenitor. Finally, this method is utilised to construct the largest bolometric CCSN bolometric light curve sample to date, and these are analytically modelled to reveal population statistics of the explosions, thus informing on the nature of the progenitors.

Increased circulating follicular helper T cells with decreased programmed death-1 in chronic renal allograft rejection

OpenAIRE

Shi, Jian; Luo, Fengbao; Shi, Qianqian; Xu, Xianlin; He, Xiaozhou; Xia, Ying

2015-01-01

Background Chronic antibody-mediated rejection is a major issue that affects long-term renal allograft survival. Since follicular helper T (Tfh) cells promote the development of antigen-specific B cells in alloimmune responses, we investigated the potential roles of Tfh cells, B cells and their alloimmune-regulating molecules in the pathogenesis of chronic renal allograft rejection in this study. Methods The frequency of Tfh, B cells and the levels of their alloimmune-regulating molecules inc...

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid.

Science.gov (United States)

Aihara, Eitaro; Mahe, Maxime M; Schumacher, Michael A; Matthis, Andrea L; Feng, Rui; Ren, Wenwen; Noah, Taeko K; Matsu-ura, Toru; Moore, Sean R; Hong, Christian I; Zavros, Yana; Herness, Scott; Shroyer, Noah F; Iwatsuki, Ken; Jiang, Peihua; Helmrath, Michael A; Montrose, Marshall H

2015-11-24

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5(+)) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5(+) cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration. Using this taste bud organoid culture system and FUCCI2 transgenic mice, we identify the stem/progenitor cells have at least 5 distinct cell cycle populations by tracking within 24-hour synchronized oscillations of proliferation. Additionally, we demonstrate that stem/progenitor cells have motility to form taste bud organoids. Taste bud organoids provides a system for elucidating mechanisms of taste signaling, disease modeling, and taste tissue regeneration.

[Molecular mechanisms of autophagy in regulating renal aging and interventional effects of Chinese herbal medicine].

Science.gov (United States)

Tu, Yue; Sun, Wei; Chen, Di-Ping; Wan, Yi-Gang; Wu, Wei; Yao, Jian

2016-11-01

Aging is the gradual functional recession of the living tissues or organs caused by a variety of genetic and environmental factors together. Autophagy is a process of degrading cytoplasmic components mediated by lysosomes in eukaryotic cells. Kidney is a typical target organ of aging. Autophagy regulates renal aging. Decrease in autophagy can accelerate renal aging,whereas,increase in autophagy can delay renal aging. During the process of regulating renal aging,the mammalian target of rapamycin (mTOR) and its related signaling pathways including the adenosine monophosphate activated protein kinase (AMPK)/mTOR,the phosphatidylinositol 3-kinase (PI3K)/ serine-threonine kinase(Akt)/mTOR,the AMPK/silent information regulation 1 (Sirt1) and transforming growth factor β (TGF-β) play the important roles in renal aging. Regulating the key signaling molecules in these pathways in vivo can control renal aging. Some Chinese herbal medicine (CHM) and their extracts with the effects of nourishing kidney or activating stasis, such as Cordyceps sinensis, curcumin and resveratrol have the beneficial effects on renal aging and/or autophagy. Therefore,revealing the pharmacological effects of CHM in anti-renal aging based on the molecular mechanisms of autophagy will become one of the development trends in the future study. Copyright© by the Chinese Pharmaceutical Association.

Endothelial Progenitor Cells as Shuttle of Anticancer Agents.

Science.gov (United States)

Laurenzana, Anna; Margheri, Francesca; Chillà, Anastasia; Biagioni, Alessio; Margheri, Giancarlo; Calorini, Lido; Fibbi, Gabriella; Del Rosso, Mario

2016-10-01

Cell therapies are treatments in which stem or progenitor cells are stimulated to differentiate into specialized cells able to home to and repair damaged tissues. After their discovery, endothelial progenitor cells (EPCs) stimulated worldwide interest as possible vehicles to perform autologous cell therapy of tumors. Taking into account the tumor-homing properties of EPCs, two different approaches to control cancer progression have been pursued by combining cell-based therapy with gene therapy or with nanomedicine. The first approach is based on the possibility of engineering EPCs to express different transgenes, and the second is based on the capacity of EPCs to take up nanomaterials. Here we review the most important progress covering the following issues: the characterization of bona fide endothelial progenitor cells, their role in tumor vascularization and metastasis, and preclinical data about their use in cell-based tumor therapy, considering antiangiogenic, suicide, immune-stimulating, and oncolytic virus gene therapy. The mixed approach of EPC cell therapy and nanomedicine is discussed in terms of plasmonic-dependent thermoablation and molecular imaging.

Bone marrow niche-inspired, multi-phase expansion of megakaryocytic progenitors with high polyploidization potential

Science.gov (United States)

Panuganti, Swapna; Papoutsakis, Eleftherios T.; Miller, William M.

2010-01-01

Background Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization, and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. Methods CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo), and all combinations of Interleukin (IL)-3, IL-6, IL-11, and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide to enhance polyploidization. Results Using Tpo+SCF+IL-3+IL-11, we obtained 3.5 CD34+CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2/pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. Nicotinamide more than doubled the percentage of high-ploidy Mks to 40%. Discussion We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed nicotinamide addition will greatly increase high-ploidy Mk production. PMID:20482285

Violencia Filio Parental: Comparando lo que informan los adolescentes y sus progenitores

OpenAIRE

Calvete, Esther; Orue, Izaskun; González-Cabrera, Joaquín

2017-01-01

El objetivo principal del presente estudio fue examinar la consistencia de los informes de progenitores e hijos a la hora de informar sobre la violencia filio-parental en una muestra comunitaria. Como objetivo secundario, se exploraron las propiedades psicométricas de la versión para progenitores del Cuestionario de Violencia Filio-Parental (Calvete, Gámez-Guadix et al., 2013). Participaron en el estudio un total de 880 adolescentes (51.70% chicas, entre 13 y 19 años) y sus progenitores (76....

Renal perfusion scintiscan

Science.gov (United States)

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

File list: NoD.Neu.50.AllAg.Fetal_neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available NoD.Neu.50.AllAg.Fetal_neural_progenitor_cells hg19 No description Neural Fetal neural progeni...tor cells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.Neu.50.AllAg.Fetal_neural_progenitor_cells.bed ...

File list: NoD.Neu.20.AllAg.Fetal_neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: NoD.Neu.05.AllAg.Fetal_neural_progenitor_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available NoD.Neu.05.AllAg.Fetal_neural_progenitor_cells hg19 No description Neural Fetal neural... progenitor cells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.Neu.05.AllAg.Fetal_neural_progenitor_cells.bed ...

Role of bone morphogenetic protein-7 in renal fibrosis

Directory of Open Access Journals (Sweden)

Rui Xi eLi

2015-04-01

Full Text Available Renal fibrosis is final common pathway of end stage renal disease. Irrespective of the primary cause, renal fibrogenesis is a dynamic process which involves a large network of cellular and molecular interaction, including pro-inflammatory cell infiltration and activation, matrix-producing cell accumulation and activation, and secretion of profibrogenic factors that modulate extracellular matrix (ECM formation and cell-cell interaction. Bone morphogenetic protein-7 is a protein of the TGF-β super family and increasingly regarded as a counteracting molecule against TGF-β. A large variety of evidence shows an anti-fibrotic role of BMP-7 in chronic kidney disease, and this effect is largely mediated via counterbalancing the profibrotic effect of TGF-β. Besides, BMP-7 reduced ECM formation by inactivating matrix-producing cells and promoting mesenchymal-to-epithelial transition (MET. BMP-7 also increased ECM degradation. Despite these observations, the anti-fibrotic effect of BMP-7 is still controversial such that fine regulation of BMP-7 expression in vivo might be a great challenge for its ultimate clinical application.

Role of bone morphogenetic protein-7 in renal fibrosis

Science.gov (United States)

Li, Rui Xi; Yiu, Wai Han; Tang, Sydney C. W.

2015-01-01

Renal fibrosis is final common pathway of end stage renal disease. Irrespective of the primary cause, renal fibrogenesis is a dynamic process which involves a large network of cellular and molecular interaction, including pro-inflammatory cell infiltration and activation, matrix-producing cell accumulation and activation, and secretion of profibrogenic factors that modulate extracellular matrix (ECM) formation and cell-cell interaction. Bone morphogenetic protein-7 is a protein of the TGF-β super family and increasingly regarded as a counteracting molecule against TGF-β. A large variety of evidence shows an anti-fibrotic role of BMP-7 in chronic kidney disease, and this effect is largely mediated via counterbalancing the profibrotic effect of TGF-β. Besides, BMP-7 reduced ECM formation by inactivating matrix-producing cells and promoting mesenchymal-to-epithelial transition (MET). BMP-7 also increased ECM degradation. Despite these observations, the anti-fibrotic effect of BMP-7 is still controversial such that fine regulation of BMP-7 expression in vivo might be a great challenge for its ultimate clinical application. PMID:25954203

Study of acute renal insufficiency and chronic renal insufficiency using radioisotopes

International Nuclear Information System (INIS)

Raynaud, C.

1976-01-01

Radioisotopic renal function tests are of assistance to diagnose and follow-up the course of renal insufficiency. The radioisotopic renogram is useful in assessing the response to therapy of child obstructive uropathies and evaluating renal transplant function. The renal scan is helpful, in an emergency service, to differenciate chronic renal insufficiency from acute renal insufficiency. Hg renal uptake test provides informations on physiopathological problems. Among them, the following problems are emphasized: evolution of a nonfunctioning kidney, control of the success of a reparative surgery and of bilateral obstructive uropathies with unilateral symptoms [fr

Activation of GLP-1 receptors on vascular smooth muscle cells reduces the autoregulatory response in afferent arterioles and increases renal blood flow.

Science.gov (United States)

Jensen, Elisa P; Poulsen, Steen S; Kissow, Hannelouise; Holstein-Rathlou, Niels-Henrik; Deacon, Carolyn F; Jensen, Boye L; Holst, Jens J; Sorensen, Charlotte M

2015-04-15

Glucagon-like peptide (GLP)-1 has a range of extrapancreatic effects, including renal effects. The mechanisms are poorly understood, but GLP-1 receptors have been identified in the kidney. However, the exact cellular localization of the renal receptors is poorly described. The aim of the present study was to localize renal GLP-1 receptors and describe GLP-1-mediated effects on the renal vasculature. We hypothesized that renal GLP-1 receptors are located in the renal microcirculation and that activation of these affects renal autoregulation and increases renal blood flow. In vivo autoradiography using (125)I-labeled GLP-1, (125)I-labeled exendin-4 (GLP-1 analog), and (125)I-labeled exendin 9-39 (GLP-1 receptor antagonist) was performed in rodents to localize specific GLP-1 receptor binding. GLP-1-mediated effects on blood pressure, renal blood flow (RBF), heart rate, renin secretion, urinary flow rate, and Na(+) and K(+) excretion were investigated in anesthetized rats. Effects of GLP-1 on afferent arterioles were investigated in isolated mouse kidneys. Specific binding of (125)I-labeled GLP-1, (125)I-labeled exendin-4, and (125)I-labeled exendin 9-39 was observed in the renal vasculature, including afferent arterioles. Infusion of GLP-1 increased blood pressure, RBF, and urinary flow rate significantly in rats. Heart rate and plasma renin concentrations were unchanged. Exendin 9-39 inhibited the increase in RBF. In isolated murine kidneys, GLP-1 and exendin-4 significantly reduced the autoregulatory response of afferent arterioles in response to stepwise increases in pressure. We conclude that GLP-1 receptors are located in the renal vasculature, including afferent arterioles. Activation of these receptors reduces the autoregulatory response of afferent arterioles to acute pressure increases and increases RBF in normotensive rats. Copyright © 2015 the American Physiological Society.

pacientes con insuficiencia renal terminal

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Karen Herrera Herrera

2011-01-01

Full Text Available La presente investigación fundamenta en la clínica psicoanalítica el estudio de dos casos de tres personas diagnosticadas con IRT que reciben tratamiento de hemodiálisis, en razón a que dadas las características y el aumento de los reportes que se presentan, ya esto se considera un problema de salud pública. El objetivo principal es describir las características dinámicas del proceso de duelo en pacientes con IRT en un centro de terapia renal de la ciudad de Cartagena. El procedimiento metodológico empleó un diseño de tipo cualitativo; la investigación se desarrolló con un diseño clínico mediante el estudio de casos, y fundamentada en la hermenéutica psicoanalítica. Todo esto respaldado en la historia clínica, la entrevista semiestructurada individual y familiar, los test proyectivos, test del dibujo de la figura humana Machover y TAT de Murray, para la debida integración de los análisis. Se concluye que predominan funciones fallidas de los progenitores y que son individuos provenientes de familias psicosomáticas, que utilizan la enfermedad para obtener un beneficio secundario.

File list: InP.Neu.50.AllAg.Fetal_neural_progenitor_cells [Chip-atlas[Archive

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Full Text Available InP.Neu.50.AllAg.Fetal_neural_progenitor_cells hg19 Input control Neural Fetal neural progeni...tor cells SRX109478 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Neu.50.AllAg.Fetal_neural_progenitor_cells.bed ...

File list: InP.Neu.20.AllAg.Fetal_neural_progenitor_cells [Chip-atlas[Archive

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Full Text Available InP.Neu.20.AllAg.Fetal_neural_progenitor_cells hg19 Input control Neural Fetal neural progeni...tor cells SRX109478 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Neu.20.AllAg.Fetal_neural_progenitor_cells.bed ...

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Full Text Available InP.Neu.05.AllAg.Fetal_neural_progenitor_cells hg19 Input control Neural Fetal neural... progenitor cells SRX109478 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Neu.05.AllAg.Fetal_neural_progenitor_cells.bed ...

Characteristics of meniscus progenitor cells migrated from injured meniscus.

Science.gov (United States)

Seol, Dongrim; Zhou, Cheng; Brouillette, Marc J; Song, Ino; Yu, Yin; Choe, Hyeong Hun; Lehman, Abigail D; Jang, Kee W; Fredericks, Douglas C; Laughlin, Barbara J; Martin, James A

2017-09-01

Serious meniscus injuries seldom heal and increase the risk for knee osteoarthritis; thus, there is a need to develop new reparative therapies. In that regard, stimulating tissue regeneration by autologous stem/progenitor cells has emerged as a promising new strategy. We showed previously that migratory chondrogenic progenitor cells (CPCs) were recruited to injured cartilage, where they showed a capability in situ tissue repair. Here, we tested the hypothesis that the meniscus contains a similar population of regenerative cells. Explant studies revealed that migrating cells were mainly confined to the red zone in normal menisci: However, these cells were capable of repopulating defects made in the white zone. In vivo, migrating cell numbers increased dramatically in damaged meniscus. Relative to non-migrating meniscus cells, migrating cells were more clonogenic, overexpressed progenitor cell markers, and included a larger side population. Gene expression profiling showed that the migrating population was more similar to CPCs than other meniscus cells. Finally, migrating cells equaled CPCs in chondrogenic potential, indicating a capacity for repair of the cartilaginous white zone of the meniscus. These findings demonstrate that, much as in articular cartilage, injuries to the meniscus mobilize an intrinsic progenitor cell population with strong reparative potential. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1966-1972, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Green Tea Polyphenols Ameliorate the Early Renal Damage Induced by a High-Fat Diet via Ketogenesis/SIRT3 Pathway

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Weijie Yi

2017-01-01

Full Text Available Scope. Several reports in the literature have suggested the renoprotective effects of ketone bodies and green tea polyphenols (GTPs. Our previous study found that GTP consumption could elevate the renal expression of the ketogenic rate-limiting enzyme, which was decreased by a high-fat diet (HFD in rats. Here, we investigated whether ketogenesis can mediate renoprotection by GTPs against an HFD. Methods and Results. Wistar rats were fed a standard or HFD with or without GTPs for 18 weeks. The renal oxidative stress level, kidney function, renal expression, and activity levels of mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA synthase 2 (HMGCS2 and sirtuin 3(SIRT3 were detected. The increased renal oxidative stress and the loss of renal function induced by the HFD were ameliorated by GTPs. Renal ketogenesis and SIRT3 expression and activity levels, which were reduced by the HFD, were restored by GTPs. In vitro, HEK293 cells were transfected with the eukaryotic expression plasmid pcDNA HMGCS2. GTP treatment could upregulate HMGCS2 and SIRT3 expression. Although SIRT3 expression was not affected by HMGCS2 transfection, the 4-hydroxy-2-nonenal (4-HNE level and the acetyl-MnSOD (K122/MnSOD ratio were reduced in HMGCS2-transfected cells in the context of H2O2. Conclusion. The ketogenesis/SIRT3 pathway mediates the renoprotection of GTPs against the oxidative stress induced by an HFD.

Shear stress upregulates regeneration-related immediate early genes in liver progenitors in 3D ECM-like microenvironments.

Science.gov (United States)

Nishii, Kenichiro; Brodin, Erik; Renshaw, Taylor; Weesner, Rachael; Moran, Emma; Soker, Shay; Sparks, Jessica L

2018-05-01

The role of fluid stresses in activating the hepatic stem/progenitor cell regenerative response is not well understood. This study hypothesized that immediate early genes (IEGs) with known links to liver regeneration will be upregulated in liver progenitor cells (LPCs) exposed to in vitro shear stresses on the order of those produced from elevated interstitial flow after partial hepatectomy. The objectives were: (1) to develop a shear flow chamber for application of fluid stress to LPCs in 3D culture; and (2) to determine the effects of fluid stress on IEG expression in LPCs. Two hours of shear stress exposure at ∼4 dyn/cm 2 was applied to LPCs embedded individually or as 3D spheroids within a hyaluronic acid/collagen I hydrogel. Results were compared against static controls. Quantitative reverse transcriptase polymerase chain reaction was used to evaluate the effect of experimental treatments on gene expression. Twenty-nine genes were analyzed, including IEGs and other genes linked to liver regeneration. Four IEGs (CFOS, IP10, MKP1, ALB) and three other regeneration-related genes (WNT, VEGF, EpCAM) were significantly upregulated in LPCs in response to fluid mechanical stress. LPCs maintained an early to intermediate stage of differentiation in spheroid culture in the absence of the hydrogel, and addition of the gel initiated cholangiocyte differentiation programs which were abrogated by the onset of flow. Collectively the flow-upregulated genes fit the pattern of an LPC-mediated proliferative/regenerative response. These results suggest that fluid stresses are potentially important regulators of the LPC-mediated regeneration response in liver. © 2017 Wiley Periodicals, Inc.

Progenitors of white dwarfs

International Nuclear Information System (INIS)

Drilling, J.S.; Schoenberner, D.

1985-01-01

Direct observational evidence is presented which indicates that the immediate progenitors of white dwarfs are the central stars of planetary nebulae (approximately 70%), other post-AGB objects (approximately 30%), and post-HB objects not massive enough to climb the AGB (approximately 0.3%). The combined birth rate for these objects is in satisfactory agreement with the death rate of main-sequence stars and the birth rate of white dwarfs

Biochemistry and biology: heart-to-heart to investigate cardiac progenitor cells.

Science.gov (United States)

Chimenti, Isotta; Forte, Elvira; Angelini, Francesco; Messina, Elisa; Giacomello, Alessandro

2013-02-01

Cardiac regenerative medicine is a rapidly evolving field, with promising future developments for effective personalized treatments. Several stem/progenitor cells are candidates for cardiac cell therapy, and emerging evidence suggests how multiple metabolic and biochemical pathways strictly regulate their fate and renewal. In this review, we will explore a selection of areas of common interest for biology and biochemistry concerning stem/progenitor cells, and in particular cardiac progenitor cells. Numerous regulatory mechanisms have been identified that link stem cell signaling and functions to the modulation of metabolic pathways, and vice versa. Pharmacological treatments and culture requirements may be exploited to modulate stem cell pluripotency and self-renewal, possibly boosting their regenerative potential for cell therapy. Mitochondria and their many related metabolites and messengers, such as oxygen, ROS, calcium and glucose, have a crucial role in regulating stem cell fate and the balance of their functions, together with many metabolic enzymes. Furthermore, protein biochemistry and proteomics can provide precious clues on the definition of different progenitor cell populations, their physiology and their autocrine/paracrine regulatory/signaling networks. Interdisciplinary approaches between biology and biochemistry can provide productive insights on stem/progenitor cells, allowing the development of novel strategies and protocols for effective cardiac cell therapy clinical translation. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Amelioration of renal lesions associated with diabetes by dietary curcumin in streptozotocin diabetic rats.

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Suresh Babu, P; Srinivasan, K

1998-04-01

Curcumin, the coloring principle of the commonly used spice turmeric (Curcuma longa) was fed at 0.5% in the diet to streptozotocin-induced diabetic Wistar rats for 8 weeks. Renal damage was assessed by the amount of proteins excreted in the urine and the extent of leaching of renal tubular enzymes: NAG, LDH, AsAT, AlAT, alkaline and acid phosphatases. The integrity of kidney was assessed by measuring the activities of several key enzymes of the renal tissue: glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, and LDH (Carbohydrate metabolism), aldose reductase and sorbitol dehydrogenase (polyol pathway), transaminases, ATPases and membrane PUFA/SFA ratio (membrane integrity). Data on enzymuria, albuminuria, activity of kidney ATPases and fatty acid composition of renal membranes in diabetic condition suggested that dietary curcumin brought about significant beneficial modulation of the progression of renal lesions in diabetes. These findings were also corroborated by histological examination of kidney sections. It is inferred that this beneficial ameliorating influence of dietary curcumin on diabetic nephropathy is possibly mediated through its ability to lower blood cholesterol levels.

Osteogenic differentiation capacity of human skeletal muscle-derived progenitor cells.

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Teruyo Oishi

Full Text Available Heterotopic ossification (HO is defined as the formation of ectopic bone in soft tissue outside the skeletal tissue. HO is thought to result from aberrant differentiation of osteogenic progenitors within skeletal muscle. However, the precise origin of HO is still unclear. Skeletal muscle contains two kinds of progenitor cells, myogenic progenitors and mesenchymal progenitors. Myogenic and mesenchymal progenitors in human skeletal muscle can be identified as CD56(+ and PDGFRα(+ cells, respectively. The purpose of this study was to investigate the osteogenic differentiation potential of human skeletal muscle-derived progenitors. Both CD56(+ cells and PDGFRα(+ cells showed comparable osteogenic differentiation potential in vitro. However, in an in vivo ectopic bone formation model, PDGFRα(+ cells formed bone-like tissue and showed successful engraftment, while CD56(+ cells did not form bone-like tissue and did not adapt to an osteogenic environment. Immunohistological analysis of human HO sample revealed that many PDGFRα(+ cells were localized in proximity to ectopic bone formed in skeletal muscle. MicroRNAs (miRNAs are known to regulate many biological processes including osteogenic differentiation. We investigated the participation of miRNAs in the osteogenic differentiation of PDGFRα(+ cells by using microarray. We identified miRNAs that had not been known to be involved in osteogenesis but showed dramatic changes during osteogenic differentiation of PDGFRα(+ cells. Upregulation of miR-146b-5p and -424 and downregulation of miR-7 during osteogenic differentiation of PDGFRα(+ cells were confirmed by quantitative real-time RT-PCR. Inhibition of upregulated miRNAs, miR-146b-5p and -424, resulted in the suppression of osteocyte maturation, suggesting that these two miRNAs have the positive role in the osteogenesis of PDGFRα(+ cells. Our results suggest that PDGFRα(+ cells may be the major source of HO and that the newly identified mi

Renal Denervation for Treating Resistant Hypertension: Current Evidence and Future Insights from a Global Perspective

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Y. Castro Torres

2013-01-01

Full Text Available Adequate blood pressure control represents an important goal for all physicians due to the complications of hypertension which reduce patients' quality of life. A new interventional strategy to reduce blood pressure has been developed for patients with resistant hypertension. Catheter-based renal denervation has demonstrated excellent results in recent investigations associated with few side effects. With the growing diffusion of this technique worldwide, some medical societies have published consensus statements to guide physicians how to best apply this procedure. Questions remain to be answered such as the long-term durability of renal denervation, the efficacy in patients with other sympathetically mediated diseases, and whether renal denervation would benefit patients with stage 1 hypertension.

Reversing resistance to vascular-disrupting agents by blocking late mobilization of circulating endothelial progenitor cells.

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Taylor, Melissa; Billiot, Fanny; Marty, Virginie; Rouffiac, Valérie; Cohen, Patrick; Tournay, Elodie; Opolon, Paule; Louache, Fawzia; Vassal, Gilles; Laplace-Builhé, Corinne; Vielh, Philippe; Soria, Jean-Charles; Farace, Françoise

2012-05-01

The prevailing concept is that immediate mobilization of bone marrow-derived circulating endothelial progenitor cells (CEP) is a key mechanism mediating tumor resistance to vascular-disrupting agents (VDA). Here, we show that administration of VDA to tumor-bearing mice induces 2 distinct peaks in CEPs: an early, unspecific CEP efflux followed by a late yet more dramatic tumor-specific CEP burst that infiltrates tumors and is recruited to vessels. Combination with antiangiogenic drugs could not disrupt the early peak but completely abrogated the late VDA-induced CEP burst, blunted bone marrow-derived cell recruitment to tumors, and resulted in striking antitumor efficacy, indicating that the late CEP burst might be crucial to tumor recovery after VDA therapy. CEP and circulating endothelial cell kinetics in VDA-treated patients with cancer were remarkably consistent with our preclinical data. These findings expand the current understanding of vasculogenic "rebounds" that may be targeted to improve VDA-based strategies. Our findings suggest that resistance to VDA therapy may be strongly mediated by late, rather than early, tumor-specific recruitment of CEPs, the suppression of which resulted in increased VDA-mediated antitumor efficacy. VDA-based therapy might thus be significantly enhanced by combination strategies targeting late CEP mobilization. © 2012 AACR

Distal renal tubular acidosis in recurrent renal stone formers

DEFF Research Database (Denmark)

Osther, P J; Hansen, A B; Røhl, H F

1989-01-01

Renal acidification ability was examined in 90 recurrent renal stone formers, using fasting morning urinary pH levels followed by a short ammonium chloride loading test in subjects with pH levels above 6.0. Fifteen patients (16.6%) revealed a distal renal tubular acidification defect: one patient......, this has important therapeutic implications. The pathological sequence in renal stone formers with dRTA is discussed....

ON THE PROGENITOR OF THE TYPE II-PLATEAU SN 2008cn in NGC 4603

International Nuclear Information System (INIS)

Elias-Rosa, Nancy; Van Dyk, Schuyler D.; Li, Weidong; Filippenko, Alexei V.; Foley, Ryan J.; Smith, Nathan; Morrell, Nidia; Gonzalez, Sergio; Hamuy, Mario; Cuillandre, Jean-Charles

2009-01-01

A trend is emerging regarding the progenitor stars that give rise to the most common core-collapse supernovae (SNe), those of Type II-Plateau (II-P): they generally appear to be red supergiants with a limited range of initial masses, ∼8-16 M sun . Here, we consider another example, SN 2008cn, in the nearly face-on spiral galaxy NGC 4603. Even with limited photometric data, it appears that SN 2008cn is not a normal SN II-P, but is of the high-luminosity subclass. Through comparison of pre- and post-explosion images obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope, we have isolated a supergiant star prior to explosion at nearly the same position as the SN. We provide evidence that this supergiant may well be the progenitor of the SN, although this identification is not entirely unambiguous. This is exacerbated by the distance to the host galaxy, 33.3 Mpc, making SN 2008cn the most distant SN II-P yet for which an attempt has been made to identify a progenitor star in pre-SN images. The progenitor candidate has a more yellow color ([V - I] 0 = 0.98 mag and T eff = 5200 ± 300 K) than generally would be expected and, if a single star, would require that it exploded during a 'blue loop' evolutionary phase, which is theoretically not expected to occur. Nonetheless, we estimate an initial mass of M ini = 15 ± 2 M sun for this star, which is within the expected mass range for SN II-P progenitors. The yellower color could also arise from the blend of two or more stars, such as a red supergiant and a brighter, blue supergiant. Such a red supergiant hidden in this blend could instead be the progenitor and would also have an initial mass within the expected progenitor mass range. Furthermore, the yellow supergiant could be in a massive, interacting binary system, analogous to the possible yellow supergiant progenitor of the high-luminosity SN II-P 2004et. Finally, if the yellow supergiant is not the progenitor, or is not a stellar

Screening renal stone formers for distal renal tubular acidosis

DEFF Research Database (Denmark)

Osther, P J; Hansen, A B; Røhl, H F

1989-01-01

A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use...

Human anti-CAIX antibodies mediate immune cell inhibition of renal cell carcinoma in vitro and in a humanized mouse model in vivo.

Science.gov (United States)

Chang, De-Kuan; Moniz, Raymond J; Xu, Zhongyao; Sun, Jiusong; Signoretti, Sabina; Zhu, Quan; Marasco, Wayne A

2015-06-11

Carbonic anhydrase (CA) IX is a surface-expressed protein that is upregulated by the hypoxia inducible factor (HIF) and represents a prototypic tumor-associated antigen that is overexpressed on renal cell carcinoma (RCC). Therapeutic approaches targeting CAIX have focused on the development of CAIX inhibitors and specific immunotherapies including monoclonal antibodies (mAbs). However, current in vivo mouse models used to characterize the anti-tumor properties of fully human anti-CAIX mAbs have significant limitations since the role of human effector cells in tumor cell killing in vivo is not directly evaluated. The role of human anti-CAIX mAbs on CAIX(+) RCC tumor cell killing by immunocytes or complement was tested in vitro by antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC) and antibody-dependent cellular phagocytosis (ADCP) as well as on CAIX(+) RCC cellular motility, wound healing, migration and proliferation. The in vivo therapeutic activity mediated by anti-CAIX mAbs was determined by using a novel orthotopic RCC xenograft humanized animal model and analyzed by histology and FACS staining. Our studies demonstrate the capacity of human anti-CAIX mAbs that inhibit CA enzymatic activity to result in immune-mediated killing of RCC, including nature killer (NK) cell-mediated ADCC, CDC, and macrophage-mediated ADCP. The killing activity correlated positively with the level of CAIX expression on RCC tumor cell lines. In addition, Fc engineering of anti-CAIX mAbs was shown to enhance the ADCC activity against RCC. We also demonstrate that these anti-CAIX mAbs inhibit migration of RCC cells in vitro. Finally, through the implementation of a novel orthotopic RCC model utilizing allogeneic human peripheral blood mononuclear cells in NOD/SCID/IL2Rγ(-/-) mice, we show that anti-CAIX mAbs are capable of mediating human immune response in vivo including tumor infiltration of NK cells and activation of T cells, resulting in

Acute renal infarction Secondary to Atrial Fibrillation Mimicking Renal Stone Picture

International Nuclear Information System (INIS)

Salih, Salih Bin; Al-Durihim, H.; Al-Jizeeri, A.; Al-Maziad, G.

2006-01-01

Acute renal infarction presents in a similar clinical picture to that of a renal stone. We report a 55-year-old Saudi female, known to have atrial fibrillation secondary to mitral stenosis due to rheumatic heart disease. She presented with a two day history of right flank pain that was treated initially as renal stone. Further investigations confirmed her as a case of renal infarction. Renal infarction is under-diagnosed because the similarity of its presentation to renal stone. Renal infarction should be considered in the differential diagnosis of loin pain, particularly in a patient with atrial fibrillation. (author)

Changes in compartments of hemospoietic and stromal marrow progenitor cells after continuous low dose gamma-irradiation

Science.gov (United States)

Domaratskaya, E.; Starostin, V.

The low dose continuous gamma-irradiation chosen corresponded with that affected the organisms onboard a spacecraft (Mitrikas, Tsetlin, 2000). F1 (CBAxC57Bl/6) male and female mice were used at 3 4 months of age. Experimental mice were- irradiated during 10 days to a total dose of 15 mGy (Co60 gamma-sources, mean dose rate of 1.5-2.0 mGy/day). Another group of intact mice served as control. Younger and advanced hemopoietic progenitors measured at day 11 (i.e. CFU -S-11) and day 7 (i.e. CFU-S-7), respectively, after transplantation of test donor cells were assayed by the method of Till and McCulloch (1961). Stromal changes were evaluated by estimation of in vitro fibroblastic colony-forming units (CFU -F ) content and by the ability of ectopically grafted (under renal capsule) stroma to regenerate the new bone marrow organ. CFU-S-11 number increased of 40% as compared with control and almost 2-fold higher than that of CFU-S-7. The CFU-F content increased almost of 3-fold. Size of ectopic marrow transplants was estimated at day 70 following grafting by counting myelokariocyte and CFU -S number that repopulated the newly formed bone marrow organ. It was found more than 2-fold increase of myelokariocytes in transplants produced by marrow stroma of irradiated donors. CFU -S contents in transplants increased strikingly in comparison to control level. CFU-S-7 and CFU-S-11 increased of 7.5- and of 3.7-fold, respectively, i.e. the rate of advanced CFU - S predominated. It should be noted a good correlation between number of stromal progenitor cells (CFU-F) and ectopic transplant sizes evaluated as myelokaryocyte counts when irradiated donors used. In the same time, if sizes of transplants was measured as CFU-S-7 and CFU - S-11 numbers, their increases were more pronounced. Therefore, continuous low dose gamma- irradiation augments significantly both hemopoietic and stromal progenitor cell number in bone marrow. Additionally, the ratio of distinct CFU -S subpopulations

Sonic hedgehog lineage in the mouse hypothalamus: from progenitor domains to hypothalamic regions

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Alvarez-Bolado Gonzalo

2012-01-01

Full Text Available Abstract Background The hypothalamus is a brain region with essential functions for homeostasis and energy metabolism, and alterations of its development can contribute to pathological conditions in the adult, like hypertension, diabetes or obesity. However, due to the anatomical complexity of the hypothalamus, its development is not well understood. Sonic hedgehog (Shh is a key developmental regulator gene expressed in a dynamic pattern in hypothalamic progenitor cells. To obtain insight into hypothalamic organization, we used genetic inducible fate mapping (GIFM to map the lineages derived from Shh-expressing progenitor domains onto the four rostrocaudally arranged hypothalamic regions: preoptic, anterior, tuberal and mammillary. Results Shh-expressing progenitors labeled at an early stage (before embryonic day (E9.5 contribute neurons and astrocytes to a large caudal area including the mammillary and posterior tuberal regions as well as tanycytes (specialized median eminence glia. Progenitors labeled at later stages (after E9.5 give rise to neurons and astrocytes of the entire tuberal region and in particular the ventromedial nucleus, but not to cells in the mammillary region and median eminence. At this stage, an additional Shh-expressing domain appears in the preoptic area and contributes mostly astrocytes to the hypothalamus. Shh-expressing progenitors do not contribute to the anterior region at any stage. Finally, we show a gradual shift from neurogenesis to gliogenesis, so that progenitors expressing Shh after E12.5 generate almost exclusively hypothalamic astrocytes. Conclusions We define a fate map of the hypothalamus, based on the dynamic expression of Shh in the hypothalamic progenitor zones. We provide evidence that the large neurogenic Shh-expressing progenitor domains of the ventral diencephalon are continuous with those of the midbrain. We demonstrate that the four classical transverse zones of the hypothalamus have clearly

Dendritic Cell Lineage Potential in Human Early Hematopoietic Progenitors

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Julie Helft

2017-07-01

Full Text Available Conventional dendritic cells (cDCs are thought to descend from a DC precursor downstream of the common myeloid progenitor (CMP. However, a mouse lymphoid-primed multipotent progenitor has been shown to generate cDCs following a DC-specific developmental pathway independent of monocyte and granulocyte poiesis. Similarly, here we show that, in humans, a large fraction of multipotent lymphoid early progenitors (MLPs gives rise to cDCs, in particular the subset known as cDC1, identified by co-expression of DNGR-1 (CLEC9A and CD141 (BDCA-3. Single-cell analysis indicates that over one-third of MLPs have the potential to efficiently generate cDCs. cDC1s generated from CMPs or MLPs do not exhibit differences in transcriptome or phenotype. These results demonstrate an early imprinting of the cDC lineage in human hematopoiesis and highlight the plasticity of developmental pathways giving rise to human DCs.

Adipose stromal cells contain phenotypically distinct adipogenic progenitors derived from neural crest.

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Yoshihiro Sowa

Full Text Available Recent studies have shown that adipose-derived stromal/stem cells (ASCs contain phenotypically and functionally heterogeneous subpopulations of cells, but their developmental origin and their relative differentiation potential remain elusive. In the present study, we aimed at investigating how and to what extent the neural crest contributes to ASCs using Cre-loxP-mediated fate mapping. ASCs harvested from subcutaneous fat depots of either adult P0-Cre/or Wnt1-Cre/Floxed-reporter mice contained a few neural crest-derived ASCs (NCDASCs. This subpopulation of cells was successfully expanded in vitro under standard culture conditions and their growth rate was comparable to non-neural crest derivatives. Although NCDASCs were positive for several mesenchymal stem cell markers as non-neural crest derivatives, they exhibited a unique bipolar or multipolar morphology with higher expression of markers for both neural crest progenitors (p75NTR, Nestin, and Sox2 and preadipocytes (CD24, CD34, S100, Pref-1, GATA2, and C/EBP-delta. NCDASCs were able to differentiate into adipocytes with high efficiency but their osteogenic and chondrogenic potential was markedly attenuated, indicating their commitment to adipogenesis. In vivo, a very small proportion of adipocytes were originated from the neural crest. In addition, p75NTR-positive neural crest-derived cells were identified along the vessels within the subcutaneous adipose tissue, but they were negative for mural and endothelial markers. These results demonstrate that ASCs contain neural crest-derived adipocyte-restricted progenitors whose phenotype is distinct from that of non-neural crest derivatives.

Human alternative Klotho mRNA is a nonsense-mediated mRNA decay target inefficiently spliced in renal disease

NARCIS (Netherlands)

Mencke, Rik; Harms, Geert; Moser, Jill; van Meurs, Matijs; Diepstra, Arjan; Leuvenink, Henri G.D.; Hillebrands, Jan-Luuk

2017-01-01

Klotho is a renal protein involved in phosphate homeostasis, which is down-regulated in renal disease. It has long been considered an anti-ageing factor. Two Klotho gene transcripts are thought to encode membrane-bound and secreted Klotho. Indeed, soluble Klotho is detectable in bodily fluids, but