Distribution and quantitative changes in amounts of aquaporin 1, 5 and 9 in the pig uterus during the estrous cycle and early pregnancy

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Skowronski Mariusz T

2010-09-01

Full Text Available Abstract Background Aquaporins (AQPs are a family of membrane channel proteins that facilitate bulk water transport. To date, 11 isoforms of AQPs have been reported to be expressed in the female and male reproductive systems. The purpose of our study was to determine the localization and quantitative changes in the expression of AQP1, 5 and 9 within the pig uterus during different stages of the estrous cycle and early pregnancy. Methods Immunoperoxidase and semi-quantitative immunoblotting techniques were used to examine the distribution and changes in amounts of AQP1, AQP5 and AQP9 in uteral cells of pigs at the early (Days 2-4, middle (10-12, late (14-16 stage of the luteal phase and late (18-20 stage of the follicular phase of the estrous cycle as well as on Days 14-16 and 30-32 of gestation (the onset and the end of implantation process. Results The results demonstrated that AQP1, 5, and 9 were clearly detected in all studied stages of the estrous cycle and pregnancy. AQP1 was localized within uterine blood vessels. In cyclic gilts, endometrial and myometrial expression of AQP1 protein did not change significantly but increased during gestation. AQP5 was localized in smooth muscle cells and uterine epithelial cells. Endometrial expression of AQP5 protein did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Myometrial expression of AQP5 did not differ significantly during the estrous cycle but increased in the pregnancy. The anti-AQP9 antibody labeled uterine epithelial cells of uterus. Endometrial expression of AQP9 did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Conclusions The results suggest that a functional and distinctive collaboration exists among diverse AQPs in water handling during the different uterine phases in the estrous cycle and

NFAT5 promotes proliferation and migration of lung adenocarcinoma cells in part through regulating AQP5 expression

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Guo, Kai, E-mail: gk161@163.com [Department of Respiration, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China); Department of Respiration, 161th Hospital, PLA, Wuhan 430015 (China); Jin, Faguang, E-mail: jinfag@fmmu.edu.cn [Department of Respiration, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China)

2015-09-25

The osmoregulated transcription factor nuclear factor of activated T-cells 5(NFAT5), has been found to play important roles in the development of many kinds of human cancers, including breast cancer, colon carcinoma, renal cell carcinoma and melanoma. The aim of the present study was to determine whether NFAT5 is involved in the proliferation and migration of lung adenocarcinoma cells. We found that NFAT5 was upregulated in lung adenocarcinoma cells and knockdown of NFAT5 decreased proliferation and migration of the cells, accompanied by a significant reduction in the expression of AQP5. AQP5 was upregulated in lung adenocarcinoma cells and knockdown of AQP5 also inhibited proliferation and migration of the cells as knockdown of NFAT5 did. Moreover, overexpression of NFAT5 promoted proliferation and migration of lung adenocarcinoma cells, accompanied by a significant increase in the expression of AQP5. These results indicate that NFAT5 plays important roles in proliferation and migration of human lung adenocarcinoma cells through regulating AQP5 expression, providing a new therapeutic option for lung adenocarcinoma therapy. - Highlights: • NFAT5 expression is higher in lung adenocarcinoma cells compared with normal cells. • NFAT5 knockdown decreases proliferation and migration of lung adenocarcinoma cells. • Knockdown of NFAT5 reduces AQP5 expression in human lung adenocarcinoma cells. • Overexpression of NFAT5 promotes proliferation and migration of lung adenocarcinoma cells. • Overexpression of NFAT5 increases AQP5 expression in human lung adenocarcinoma cells.

NFAT5 promotes proliferation and migration of lung adenocarcinoma cells in part through regulating AQP5 expression

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Guo, Kai; Jin, Faguang

2015-01-01

The osmoregulated transcription factor nuclear factor of activated T-cells 5(NFAT5), has been found to play important roles in the development of many kinds of human cancers, including breast cancer, colon carcinoma, renal cell carcinoma and melanoma. The aim of the present study was to determine whether NFAT5 is involved in the proliferation and migration of lung adenocarcinoma cells. We found that NFAT5 was upregulated in lung adenocarcinoma cells and knockdown of NFAT5 decreased proliferation and migration of the cells, accompanied by a significant reduction in the expression of AQP5. AQP5 was upregulated in lung adenocarcinoma cells and knockdown of AQP5 also inhibited proliferation and migration of the cells as knockdown of NFAT5 did. Moreover, overexpression of NFAT5 promoted proliferation and migration of lung adenocarcinoma cells, accompanied by a significant increase in the expression of AQP5. These results indicate that NFAT5 plays important roles in proliferation and migration of human lung adenocarcinoma cells through regulating AQP5 expression, providing a new therapeutic option for lung adenocarcinoma therapy. - Highlights: • NFAT5 expression is higher in lung adenocarcinoma cells compared with normal cells. • NFAT5 knockdown decreases proliferation and migration of lung adenocarcinoma cells. • Knockdown of NFAT5 reduces AQP5 expression in human lung adenocarcinoma cells. • Overexpression of NFAT5 promotes proliferation and migration of lung adenocarcinoma cells. • Overexpression of NFAT5 increases AQP5 expression in human lung adenocarcinoma cells

Aquaporin-11 (AQP11 Expression in the Mouse Brain

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Shin Koike

2016-06-01

Full Text Available Aquaporin-11 (AQP11 is an intracellular aquaporin expressed in various tissues, including brain tissues in mammals. While AQP11-deficient mice have developed fatal polycystic kidneys at one month old, the role of AQP11 in the brain was not well appreciated. In this study, we examined the AQP11 expression in the mouse brain and the brain phenotype of AQP11-deficient mice. AQP11 messenger ribonucleic acid (mRNA and protein were expressed in the brain, but much less than in the thymus and kidney. Immunostaining showed that AQP11 was localized at the epithelium of the choroid plexus and at the endothelium of the brain capillary, suggesting that AQP11 may be involved in water transport at the choroid plexus and blood-brain barrier (BBB in the brain. The expression of AQP4, another brain AQP expressed at the BBB, was decreased by half in AQP11-deficient mice, thereby suggesting the presence of the interaction between AQP11 and AQP4. The brain of AQP11-deficient mice, however, did not show any morphological abnormalities and the function of the BBB was intact. Our findings provide a novel insight into a water transport mechanism mediated by AQPs in the brain, which may lead to a new therapy for brain edema.

Enhanced Autophagy in Polycystic Kidneys of AQP11 Null Mice

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Yasuko Tanaka

2016-11-01

Full Text Available Aquaporin-11 (AQP11 is an intracellular water channel expressed at the endoplasmic reticulum (ER of the proximal tubule. Its gene disruption in mice leads to intracellular vacuole formation at one week and the subsequent development of polycystic kidneys by three weeks. As the damaged proximal tubular cells with intracellular vacuoles form cysts later, we postulated that autophagy may play a role in the cyst formation and examined autophagy activity before and after cyst development in AQP11(−/− kidneys. PCR analysis showed the increased expression of the transcript encoding LC3 (Map1lc3b as well as other autophagy-related genes in AQP11(−/− mice. Using green fluorescent protein (GFP-LC3 transgenic mice and AQP11(−/− mice, we found that the number of GFP-LC3–positive puncta was increased in the proximal tubule of AQP11(−/− mice before the cyst formation. Interestingly, they were also observed in the cyst-lining epithelial cell. Further PCR analyses revealed the enhanced expression of apoptosis-related and ER stress–related caspase genes before and after the cyst formation, which may cause the enhanced autophagy. These results suggest the involvement of autophagy in the development and maintenance of kidney cysts in AQP11(−/− mice.

The Effect of a High-Protein Diet and Exercise on Cardiac AQP7 and GLUT4 Gene Expression.

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Palabiyik, Orkide; Karaca, Aziz; Taştekin, Ebru; Yamasan, Bilge Eren; Tokuç, Burcu; Sipahi, Tammam; Vardar, Selma Arzu

2016-10-01

High-protein (HP) diets are commonly consumed by athletes despite their potential health hazard, which is postulated to enforce a negative effect on bone and renal health. However, its effects on heart have not been known yet. Aquaporin-7 (AQP7) is an aquaglyceroporin that facilitates glycerol and water transport. Glycerol is an important cardiac energy production substrate, especially during exercise, in conjunction with fatty acids and glucose. Glucose transporter 4 (GLUT4) is an insulin-sensitive glucose transporter in heart. We aimed to investigate the effect of HPD on AQP7 and GLUT4 levels in the rat heart subjected to exercise. Male Sprague-Dawley rats were divided into control (n = 12), exercise (E) training (n = 10), HPD (n = 12), and HPD-E training (n = 9) groups. The HPD groups were fed a 45 % protein-containing diet 5 weeks. The HPD-E and E groups were performed the treadmill exercise during the 5-week study period. Real-time polymerase chain reaction and immunohistochemistry techniques were used to determine the gene expression and localization of AQP7 and GLUT4 in heart tissue. Results of relative gene expression were calculated by the 'Pfaffl' mathematical method using the REST program. Differences in AQP7 and GLUT4 gene expression were expressed as fold change compared to the control group. Heart weight/tibia ratio and ventricular wall thickness were evaluated as markers of cardiac hypertrophy. Further, serum glucose, glycerol, and insulin levels were also measured. AQP7 gene expression was found to be increased in the E (3.47-fold, p protein expression was also increased in the HPD and HPD-E groups (p protein expression was significantly increased in the E, HPD, and HPD-E groups compared to the control group (p = 0.024, p protein diet groups (C and E). Serum insulin levels were higher for HPD groups compared with the normal-protein diet groups (p < 0.001), whereas no differences were observed between the exercise and sedentary

There is less MRI brain lesions and no characteristic MRI Brain findings in IIDDs patients with positive AQP4 serology among Malaysians.

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Abdullah, Suhailah; Fadzli, Farhana; Ramli, Norlisah; Tan, Chong Tin

2017-02-01

The recently introduced International Consensus diagnostic criteria for diagnosis of neuromyelitis spectrum disorder include patients who are seronegative for AQP4 antibody. The criteria are dependent on typical MRI changes in the spinal cord, optic nerve and brain. This study aims to determine whether there are significant differences in the MRI brain images between AQP4 positive and negative patients with IIDDs. MRI brain of patients with a diagnosis of IIDDs presented to the Hospital from 2010 to 2015 was analysed. The MRI was assessed by 2 radiologists blinded to the AQP4 status, on features said to be typical of NMOSD and MS. Thirty nine patients fulfilled the criteria and were included in the study. They consisted of 19 AQP4 seropositive and 20 AQP4 seronegative patients. The mean age was older (37.0 vs. 28.8 years) among the AQP4 positive group. The majority of the patients were ethnic Chinese (72%), followed by the Malays and Indians. Those with AQP4 seropositive status generally has less brain lesions, and significantly less fulfilling the McDonald DIS criteria as compared to those with AQP4 seronegative status (15.8% vs. 60.0%, p=0.005). None of the seven cerebral MRI features highlighted in NMOSD 2015 diagnostic criteria, said to be characteristic of NMOSD was more common among the AQP4 positive patients. These features were in fact seen less frequently among the AQP4 seropositive patients. An example was the extensive hemispheric lesion seen in 10.5% of AQP4 seropositive patients vs. 45% of that AQP4 seronegative group. There was no characteristic MRI brain features in the Malaysian AQP4 seropositive IIDD patients versus those who are seronegative. This could be a reflection of ethnical difference. Copyright © 2017 Elsevier B.V. All rights reserved.

Correlation between AQP4 mRNA and PKC activity after gamma knife radiosurgery in rat brain

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Shen Guangjian; Xu Minhui; Gen Mingying; Tang Wenyuan; Sun Shanquan

2009-01-01

Objective: To explore the change of AQP4 mRNA expression and the correlation with PKC in rat brain irradiated by γ knife radiosurgery (GKS). Methods: 30 Wistar rats were used in the study. The experimental radiosurgery model was established by radiating rat left rotral caudate nucleus with GKS(one target, 100 Gy in isocenter dose and 4 mm in collimator), and was examined at 1,3,7,15,30 and 45 d post-irradiation. AQP4 mRNA expression, PKC activity and free intracellular calcium ion concentration ([Ca 2+ ] i ) of brain tissue were determined by RT-PCR, liquid scintillation counter and Fura-2/AM, respectively. Results: AQP4 mRNA expression increased gradually from 0.99 ± 0.05 in control group to 2.32 ± 0.10 at 30 d post-irradiation, and decreased to 2.21 ± 0.08 at 45 d post-irradiation. The PKC activity and the free [Ca 2+ ] i decreased gradually from 0.5896 ± 0.2101 and 455.82 ± 20.13 in control group to 0.0404 ± 0.0294 and 196.72 ± 9.87 at 30 d post- irradiation, and increased to 0.1050 ± 0.0607 and 219.26 ± 10.43 at 45 d post-irradiation, respectively. The significant differences were found between experimental group and control group except at 1 d post-irradiation (P 2+ ] i and the PKC activity was positive (P=0.001, r=0.959). Conclusions: The increased expression of AQP4 mRNA might result from the inhibition of PKC activity due to the reduction of free [Ca 2+ ] i after GKS. (authors)

Role of AQP4 Antibody Serostatus and its Prediction of Visual Outcome in Neuromyelitis Optica: A Systematic Review and Meta-Analysis.

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Lin, Nan; Liu, Qing; Wang, Xiaoyu; Ma, Jianmei; Li, Yuyuan

2017-01-01

Backgroud: Neuromyelitis optica (NMO) is an autoimmune inflammatory disorder, which is characterized by severe attacks of optic neuritis and myelitis. Antibodies (Ab) to aquaporin-4 (AQP4) (or NMO-IgG) as a serological biomarker of NMO have been widespread used. Nevertheless, some NMO patients remain seronegative for AQP4-Ab and/or have no detected optic nerve involvement. In addition, no consensus exists on the association between AQP4-Ab serostatus and visual outcome in NMO. To drive a more precise estimate of this postulated relationship, a metaanalysis was performed based on existing relevant studies. Studies were searched by PubMed and MEDLINE up to March 2016. Study quality was assessed, and meta-analysis was conducted using the RevMan 5.1. Odds ratios with 95% confidence interval were calculated and funnel plot was applied to assess the potential publication bias. In a total of 1288 relevant studies, 18 studies satisfied the eligibility criteria and were included in the systemic review. Only 9 studies appeared eligible for the meta-analysis, together including 624 AQP4-Ab-positive and 119 AQP4-Ab-negative NMO patients. The results revealed associations between AQP4-Ab seropositivity and visual impairment in NMO (OR, 3.16; 95% CI, 1.09, 9.19; P = 0.03). The results of subgroup analyses based on different methods of AQP-4 detection also showed significantly differences between AQP4-Ab seropositivity and visual impairment in NMO, especially in CBA subgroup. This meta-analysis indicates that AQP4-Ab serostatus has the positive with poor visual outcome in NMO. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Phosphorylation of human aquaporin 2 (AQP2) allosterically controls its interaction with the lysosomal trafficking protein LIP5.

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Roche, Jennifer Virginia; Survery, Sabeen; Kreida, Stefan; Nesverova, Veronika; Ampah-Korsah, Henry; Gourdon, Maria; Deen, Peter M T; Törnroth-Horsefield, Susanna

2017-09-01

The interaction between the renal water channel aquaporin-2 (AQP2) and the lysosomal trafficking regulator-interacting protein LIP5 targets AQP2 to multivesicular bodies and facilitates lysosomal degradation. This interaction is part of a process that controls AQP2 apical membrane abundance in a vasopressin-dependent manner, allowing for urine volume adjustment. Vasopressin regulates phosphorylation at four sites within the AQP2 C terminus (Ser 256 , Ser 261 , Ser 264 , and Thr 269 ), of which Ser 256 is crucial and sufficient for AQP2 translocation from storage vesicles to the apical membrane. However, whether AQP2 phosphorylation modulates AQP2-LIP5 complex affinity is unknown. Here we used far-Western blot analysis and microscale thermophoresis to show that the AQP2 binds LIP5 in a phosphorylation-dependent manner. We constructed five phospho-mimicking mutants (S256E, S261E, S264E, T269E, and S256E/T269E) and a C-terminal truncation mutant (ΔP242) that lacked all phosphorylation sites but retained a previously suggested LIP5-binding site. CD spectroscopy indicated that wild-type AQP2 and the phospho-mimicking mutants had similar overall structure but displayed differences in melting temperatures possibly arising from C-terminal conformational changes. Non-phosphorylated AQP2 bound LIP5 with the highest affinity, whereas AQP2-ΔP242 had 20-fold lower affinity as determined by microscale thermophoresis. AQP2-S256E, S261E, T269E, and S256E/T269E all had reduced affinity. This effect was most prominent for AQP2-S256E, which fits well with its role in apical membrane targeting. AQP2-S264E had affinity similar to non-phosphorylated AQP2, possibly indicating a role in exosome excretion. Our data suggest that AQP2 phosphorylation allosterically controls its interaction with LIP5, illustrating how altered affinities to interacting proteins form the basis for regulation of AQP2 trafficking by post-translational modifications. © 2017 by The American Society for

Expression of AQP3 gene in chronic atrophic and chronic superficial gastritis patients

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Shijun Zhang

2007-12-01

Full Text Available BACKGROUND: Most studies about aquaporin 3 (AQP3 in the gastrointestinal tract were carried out on both in vivo and in vitro. The role of AQP3-mediated water transport in human gastrointestinal tract is still unclear. Our aim in this study was to explore the expression of AQP3 gene in chronic atrophic gastritis (CAG and chronic superficial gastritis (CSG atients and to determine its possible function in the development of gastritis.
METHODS: Twenty-two outpatients diagnosed as CSG and 12 outpatients diagnosed as CAG were selected randomly. Ten cases of healthy individuals were selected as normal control group. In all cases, AQP3 gene expression of gastric mucosa was detected by fluorescence quantitative polymerase chain reaction (FQ-PCR.
RESULTS: The AQP3 gene expression was significantly higher in gastric mucosa of CSG and healthy individuals than that in CAG (P<0.01. However, there was no significant difference in the AQP3 gene expression between helicobacter pylori positive patients and helicobacter pylori negative patients (P>0.05.
CONCLUSIONS: AQP3 expression might play certain role in the occurrence and development of gastritis.
KEY WORDS: Aquaporin 3, chronic superficial gastritis, chronic atrophic gastritis.

Chimerization at the AQP2–AQP3 locus is the genetic basis of melarsoprol–pentamidine cross-resistance in clinical Trypanosoma brucei gambiense isolates

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Fabrice E. Graf

2015-08-01

Full Text Available Aquaglyceroporin-2 is a known determinant of melarsoprol–pentamidine cross-resistance in Trypanosoma brucei brucei laboratory strains. Recently, chimerization at the AQP2–AQP3 tandem locus was described from melarsoprol–pentamidine cross-resistant Trypanosoma brucei gambiense isolates from sleeping sickness patients in the Democratic Republic of the Congo. Here, we demonstrate that reintroduction of wild-type AQP2 into one of these isolates fully restores drug susceptibility while expression of the chimeric AQP2/3 gene in aqp2–aqp3 null T. b. brucei does not. This proves that AQP2–AQP3 chimerization is the cause of melarsoprol–pentamidine cross-resistance in the T. b. gambiense isolates.

Overexpression of the wheat aquaporin gene, TaAQP7, enhances drought tolerance in transgenic tobacco.

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Shiyi Zhou

Full Text Available Aquaporin (AQP proteins have been shown to transport water and other small molecules through biological membranes, which is crucial for plants to combat stress caused by drought. However, the precise role of AQPs in drought stress response is not completely understood in plants. In this study, a PIP2 subgroup gene AQP, designated as TaAQP7, was cloned and characterized from wheat. Expression of TaAQP7-GFP fusion protein revealed its localization in the plasma membrane. TaAQP7 exhibited high water channel activity in Xenopus laevis oocytes and TaAQP7 transcript was induced by dehydration, and treatments with polyethylene glycol (PEG, abscisic acid (ABA and H(2O(2. Further, TaAQP7 was upregulated after PEG treatment and was blocked by inhibitors of ABA biosynthesis, implying that ABA signaling was involved in the upregulation of TaAQP7 after PEG treatment. Overexpression of TaAQP7 increased drought tolerance in tobacco. The transgenic tobacco lines had lower levels of malondialdehyde (MDA and H(2O(2, and less ion leakage (IL, but higher relative water content (RWC and superoxide dismutase (SOD and catalase (CAT activities when compared with the wild type (WT under drought stress. Taken together, our results show that TaAQP7 confers drought stress tolerance in transgenic tobacco by increasing the ability to retain water, reduce ROS accumulation and membrane damage, and enhance the activities of antioxidants.

Vasopressin increases S261 phosphorylation in AQP2-P262L, a mutant in recessive nephrogenic diabetes insipidus

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Trimpert, C.; van den Berg, D.T.; Fenton, R.A.; Klussmann, E.; Deen, P.M.T.

2012-01-01

Background Mutations in the aquaporin-2 (AQP2) gene cause nephrogenic diabetes insipidus (NDI), a renal disorder characterized by polyuria due to a lacking antidiuretic response to vasopressin. While most AQP2 mutants in recessive NDI are misfolded and retained in the endoplasmic reticulum,

Pretreatment with AQP4 and NKCC1 Inhibitors Concurrently Attenuated Spinal Cord Edema and Tissue Damage after Spinal Cord Injury in Rats.

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Yan, Xiaodong; Liu, Juanfang; Wang, Xiji; Li, Wenhao; Chen, Jingyuan; Sun, Honghui

2018-01-01

Spinal cord injury (SCI) affects more than 2.5 million people worldwide. Spinal cord edema plays critical roles in the pathological progression of SCI. This study aimed to delineate the roles of aquaporin 4 (AQP4) and Na + -K + -Cl - cotransporter 1 (NKCC1) in acute phase edema and tissue destruction after SCI and to explore whether inhibiting both AQP4 and NKCC1 could improve SCI-induced spinal edema and damage. Rat SCI model was established by modified Allen's method. Spinal cord water content, cerebrospinal fluid lactose dehydrogenase (LDH) activity, AQP4 and NKCC1 expression, and spinal cord pathology from 30 min to 7 days after SCI were monitored. Additionally, aforementioned parameters in rats treated with AQP4 and/or NKCC1 inhibitors were assessed 2 days after SCI. Spinal cord water content was significantly increased 1 h after SCI while AQP4 and NKCC1 expression and spinal fluid LDH activity elevated 6 h after SCI. Spinal cord edema and spinal cord destruction peaked around 24 h after SCI and maintained at high levels thereafter. Treating rats with AQP4 inhibitor TGN-020 and NKCC1 antagonist bumetanide significantly reduced spinal cord edema, tissue destruction, and AQP4 and NKCC1 expression after SCI in an additive manner. These results demonstrated the benefits of simultaneously inhibiting both AQP4 and NKCC1 after SCI.

[Effect of Zhenwu Tang on regulating of "AVP-V2R-AQP2" pathway in NRK-52E cells].

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Zhou, Xiao-Jie; Bao, Yu-Ting; Chen, Hong-Shu; Xuan, Ling; Chen, Xue-Ming; Zhang, Jie-Ying; Yang, Yuan-Xiao; Li, Chang-Yu

2018-02-01

This study was aimed to investigate the effect and mechanism of Zhenwu Tang on AVP-V2R-AQP2 pathway in NRK-52E cells in vitro . Forty eight male SD rats were randomly divided into eight groups with 6 animals in each group. Distilled water or 22.68 g·kg⁻¹·d⁻¹ Zhenwu Tang(calculated by raw drug dosage meter) was given by gavage. Blood samples were collected by cardiac puncture， and the medicated serum was centrifuged from the blood by 3 000 r·min⁻¹. NRK-52E cells were treated with different medicated serum or dDAVP. The condition of cell proliferation was detected by RTCA. The distribution of V2R and AQP2 in cells were detected by immunofluorescence. The expression of V2R， PKA and AQP2 were detected by Western blot and AQP2 mRNA level was detected by real-time PCR. Results showed that the level of AQP2 mRNA( P Tang medicated serum for 24 h were significantly higher than that of normal rat serum group. And the expression level of V2R， p-AQP2 and AQP2( P Tang medicated serum could increase the expression level of V2R， PKA and AQP2 which exist in AVP-V2R-AQP2 pathway in NRK-52E， and there is synergistic effect between Zhenwu Tang medicated serum and dDAVP. So the pathway of AVP-V2R-AQP2 may be one of the mechanism for which Zhenwu Tang regulate balance of water transportation. Copyright© by the Chinese Pharmaceutical Association.

Hypoxia and hypoxia mimetics decrease aquaporin 5 (AQP5 expression through both hypoxia inducible factor-1α and proteasome-mediated pathways.

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Jitesh D Kawedia

Full Text Available The alveolar epithelium plays a central role in gas exchange and fluid transport, and is therefore critical for normal lung function. Since the bulk of water flux across this epithelium depends on the membrane water channel Aquaporin 5 (AQP5, we asked whether hypoxia had any effect on AQP5 expression. We show that hypoxia causes a significant (70% decrease in AQP5 expression in the lungs of mice exposed to hypoxia. Hypoxia and the hypoxia mimetic, cobalt, also caused similar decreases in AQP5 mRNA and protein expression in the mouse lung epithelial cell line MLE-12. The action of hypoxia and cobalt on AQP5 transcription was demonstrated by directly quantifying heternonuclear RNA by real-time PCR. Dominant negative mutants of Hypoxia Inducible Factor (HIF-1α and HIF-1α siRNA blocked the action of cobalt, showing that HIF-1α is a key component in this mechanism. The proteasome inhibitors, lactacystin or proteasome inhibitor-III completely abolished the effect of hypoxia and cobalt both at the protein and mRNA level indicating that the proteasome pathway is probably involved not only for the stability of HIF-1α protein, but for the stability of unidentified transcription factors that regulate AQP5 transcription. These studies reveal a potentially important physiological mechanism linking hypoxic stress and membrane water channels.

Hypoxia and Hypoxia Mimetics Decrease Aquaporin 5 (AQP5) Expression through Both Hypoxia Inducible Factor-1α and Proteasome-Mediated Pathways

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Kawedia, Jitesh D.; Yang, Fan; Sartor, Maureen A.; Gozal, David; Czyzyk-Krzeska, Maria; Menon, Anil G.

2013-01-01

The alveolar epithelium plays a central role in gas exchange and fluid transport, and is therefore critical for normal lung function. Since the bulk of water flux across this epithelium depends on the membrane water channel Aquaporin 5 (AQP5), we asked whether hypoxia had any effect on AQP5 expression. We show that hypoxia causes a significant (70%) decrease in AQP5 expression in the lungs of mice exposed to hypoxia. Hypoxia and the hypoxia mimetic, cobalt, also caused similar decreases in AQP5 mRNA and protein expression in the mouse lung epithelial cell line MLE-12. The action of hypoxia and cobalt on AQP5 transcription was demonstrated by directly quantifying heternonuclear RNA by real-time PCR. Dominant negative mutants of Hypoxia Inducible Factor (HIF-1α) and HIF-1α siRNA blocked the action of cobalt, showing that HIF-1α is a key component in this mechanism. The proteasome inhibitors, lactacystin or proteasome inhibitor-III completely abolished the effect of hypoxia and cobalt both at the protein and mRNA level indicating that the proteasome pathway is probably involved not only for the stability of HIF-1α protein, but for the stability of unidentified transcription factors that regulate AQP5 transcription. These studies reveal a potentially important physiological mechanism linking hypoxic stress and membrane water channels. PMID:23469202

AQP4 expression and its relationship with brain edema after gamma kife radiosurgery in rats

International Nuclear Information System (INIS)

Shen Guangjian; Xu Minhui; Zou Yongwen; Gen Mingying; Li Feipeng; Tang Wenyuan; Sun Shanquan

2007-01-01

Objective: To explore AQP4 expression and its relationship with brain edema after gamma knife radiosurgery (GKRS) in rats. Methods: Wistar rats were divided into two groups-the control group and experimental group. The experimental group model was established by radiating rat left rotral caudate nucleus with GKRS (100 Gy, 4 mm), and was examinded at interval times of 1 d, 3 d, 7 d, 15 d, 30 d and 45 d. Brain water content (BWC) was determined by wet-dry weighing method. AQP4 expression on mRNA and protein were measured by immunohistochemistry (ICH) and in situ hybridization (ISH). Results: In control group, AQP4 protein and its mRNA were expressed in subpial astrocytes, choroid plexus, ependyma and perivascular astrocytes. After GKRS, AQP4 protein and its mRNA in these sites were enhanced, and became most remarkable at 30 d. The positive corrlationship was showed between AQP4 and its mRNA, and AQP4 and BWC. Conclusions: AQP4 protein and its mRNA can be induced in some brain zone after irradiating rat left rotral caudate nucleus with GKRS. The increased expression of AQP4 and its mRNA may play a role in the ocurrence or development of brain edema after GKRS. (authors)

Analysis of aquaporin 9 expression in human epidermis and cultured keratinocytes

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Yoshinori Sugiyama

2014-01-01

Full Text Available Aquaporin 9 (AQP9 is a member of the aquaglyceroporin family that transports glycerol, urea and other small solutes as well as water. Compared to the expression and function in epidermal keratinocytes of AQP3, another aquaglyceroporin, our knowledge of epidermal AQP9 remains elusive. In this study, we investigated the expression of AQP9 in the human epidermis and cultured keratinocytes. Immunofluorescence studies revealed that AQP9 expression is highly restricted to the stratum granulosum of the human epidermis, where occludin is also expressed at the tight junctions. Interestingly, the AQP3 staining decreased sharply below the cell layers in which AQP9 is expressed. In cultured normal human epidermal keratinocytes (NHEK, knock-down of AQP9 expression in the differentiated cells induced by RNA interference reduced glycerol uptake, which was not as pronounced as was the case with AQP3 knock-down cells. In contrast, similar reduction of urea uptake was detected in AQP9 and AQP3 knock-down cells. These findings suggested that AQP9 expression in NHEK facilitates at least the transport of glycerol and urea. Finally, we analyzed the effect of retinoic acid (RA, a potent stimulator of keratinocyte proliferation, on AQP3 and AQP9 mRNA expression in differentiated NHEK. Stimulation with RA at 1 μM for 24 h augmented AQP3 expression and down-regulated AQP9 expression. Collectively, these results indicate that AQP9 expression in epidermal keratinocytes is regulated in a different manner from that of AQP3.

Immunohistochemical expression of AQP-3 in vitiligo: a new potential guide for disease activity.

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Hodeib, Abeer; Hegab, Doaa; Rizk, Omnia; Mohammed, Shahdan

2017-08-01

Vitiligo is a depigmenting skin disorder, with disappearance of functioning epidermal melanocytes. Aquaporin-3 (AQP-3) is an aquaglyceroporin expressed in epidermal keratinocytes, where it shares in regulating their proliferation and differentiation, and so it might affect melanocytes indirectly. So far, little is known regarding its possible role in vitiligo. This work aimed to study the changes in immunohistochemical expression of AQP-3 protein in vitiligo to detect its possible role in disease pathogenesis. Skin biopsies were taken from lesional skin of 30 vitiligo patients in addition to 20 normal controls. Epidermal immunohistochemical expression of AQP-3 was assessed as: +3 = strong expression, +2 = moderate, +1= weak and 0= negative expression. AQP-3 was significantly less expressed in vitiligo epidermis than control (PVitiligo Index of Disease Activity (r =-0.505, P=0.004). Reduced epidermal AQP-3 may have a role in impaired melanocyte survival in vitiligo, and might be a potential negative biological marker for vitiligo activity. Larger trials should further elucidate the effect of changes in epidermal AQP-3 expression in development of vitiligo, and that might pave the road for discovering new therapeutic modalities for the disease.

Lack of arginine vasopressin-induced phosphorylation of aquaporin-2 mutant AQP2-R254L explains dominant nephrogenic diabetes insipidus.

NARCIS (Netherlands)

Mattia, F.P. de; Savelkoul, P.J.M.; Kamsteeg, E.J.; Konings, I.B.M.; Sluijs, P. van der; Mallmann, R.; Oksche, A.; Deen, P.M.T.

2005-01-01

Water homeostasis in humans is regulated by vasopressin, which induces the translocation of homotetrameric aquaporin-2 (AQP2) water channels from intracellular vesicles to the apical membrane of renal principal cells. For this process, phosphorylation of AQP2 at S256 by cAMP-dependent protein kinase

Correlation between salivary secretion and salivary AQP5 levels in health and disease.

Science.gov (United States)

Wang, Di; Iwata, Fusako; Muraguchi, Masahiro; Ooga, Keiko; Ohmoto, Yasukazu; Takai, Masaaki; Mori, Toyoki; Ishikawa, Yasuko

2009-01-01

Saliva samples are useful for noninvasive diagnosis of oral and systemic diseases. The water channel protein aquaporin-5 (AQP5) is released into human saliva. Salivary AQP5 levels show a diurnal variation with the secretion of high levels during the waking hours. An age-related decrease in salivary AQP5 levels parallels a decrease in the volume of saliva. Cevimeline, a muscarinic acetylcholine receptor (mAChR) agonist, induces the release of AQP5. Changes in salivary AQP5 levels after cevimeline administration occur simultaneously with changes in saliva flow rate. AQP5 and lipid rafts are released separately from human salivary glands upon M(3) mAChR stimulation. In patients with diabetes mellitus or Sjögren's syndrome, a decrease in salivary secretion occurs concomitantly with low salivary AQP5 levels. Salivary AQP5 levels correlate with salivary secretion in both healthy and disease states, suggesting that changes in salivary AQP5 levels can be used as an indicator of salivary flow rate and the effect of M(3) mAChR agonists on human salivary glands.

Regulation and Function of AQP4 in the Central Nervous System

DEFF Research Database (Denmark)

Assentoft, Mette; Larsen, Brian Roland; MacAulay, Nanna

2015-01-01

Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. Based on studies on AQP4(-/-) mice, AQP4 has been assigned physiological roles in stimulus-induced K(+) clearance, paravascular fluid ...

The Expression of AQP1 IS Modified in Lung of Patients With Idiopathic Pulmonary Fibrosis: Addressing a Possible New Target

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Ana Galán-Cobo

2018-05-01

Full Text Available Activation of the epithelial-mesenchymal transition process (EMT by which alveolar cells in human lung tissue undergo differentiation giving rise to a mesenchymal phenotype (fibroblast/miofibroblasts has been well recognized as a key element in the origin of idiopathic pulmonary fibrosis (IPF. Here we analyzed expression of AQP1 in lung biopsies of patients diagnosed with IPF, and compared it to biopsies derived from patients with diverse lung pneumonies, such as hypersensitivity pneumonitis, sarcoidosis or normal lungs. Immunostaining for AQP1 showed a clear increment of AQP1 localized in the alveolar epithelium in biopsies from IPF patients alone. Moreover, to examine the possible participation of AQP1 in the pathophysiology of IPF, we evaluated its role in the pro-fibrotic transformation induced by transforming growth factor (TGF-β in vitro. Human alveolar epithelial cells (A549, and fibroblasts derived from an IPF patient (LL29, or fibroblasts from healthy normal lung tissue (MRC-5, were treated with TGF-β, and levels of expression of AQP1, as well as those of E-cadherin, vimentin, α-SMA and collagen were analyzed by RT-qPCR, western blot and immunohistochemistry. An increase of AQP1 mRNA and protein after TGF-β treatment (4–72h was observed either in A549 or IPF fibroblast-LL29 but not in MRC-5 fibroblasts. A gradual reduction of E-cadherin, and increased expression of vimentin, with no changes in α-SMA levels were observed in A549. Whereas in LL29 and MRC-5, TGF-β1 elicited a large production of collagen and α-SMA that was significantly greater in IPF fibroblast-LL29. Changes observed are consistent with activation of EMT by TGF-β, but whether modifications in AQP1 expression are responsible or independent events occurring at the same time is still unknown. Our results suggest that AQP1 plays a role in the pro-fibrotic TGF-β action and contributes to the etiology and pathophysiology of IPF. Understanding AQP1's role will help us

Disruption of cyclooxygenase-2 prevents downregulation of cortical AQP2 and AQP3 in response to bilateral ureteral obstruction in the mouse

DEFF Research Database (Denmark)

Nilsson, Line; Madsen, Kirsten Morill; Topcu, Sukru Oguzkan

2012-01-01

Bilateral ureteral obstruction (BUO) in rats is associated with increased cyclooxygenase type 2 (COX-2) expression, and selective COX-2 inhibition prevents downregulation of aquaporins (AQPs) in response to BUO. It was hypothesized that a murine model would display similar changes in renal COX-2 ...

Antenatal Corticosteroids and Postnatal Fluid Restriction Produce Differential Effects on AQP3 Expression, Water Handling, and Barrier Function in Perinatal Rat Epidermis

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Johan Agren

2010-01-01

Full Text Available Loss of water through the immature skin can lead to hypothermia and dehydration in preterm infants. The water and glycerol channel aquaglyceroporin-3 (AQP3 is abundant in fetal epidermis and might influence epidermal water handling and transepidermal water flux around birth. To investigate the role of AQP3 in immature skin, we measured in vivo transepidermal water transport and AQP3 expression in rat pups exposed to clinically relevant fluid homeostasis perturbations. Preterm (E18 rat pups were studied after antenatal corticosteroid exposure (ANS, and neonatal (P1 rat pups after an 18 h fast. Transepidermal water loss (TEWL and skin hydration were determined, AQP3 mRNA was quantified by RT-PCR, and in-situ hybridization and immunocytochemistry were applied to map AQP3 expression. ANS resulted in an improved skin barrier (lower TEWL and skin hydration, while AQP3 mRNA and protein increased. Fasting led to loss of barrier integrity along with an increase in skin hydration. These alterations were not paralleled by any changes in AQP3. To conclude, antenatal corticosteroids and early postnatal fluid restriction produce differential effects on skin barrier function and epidermal AQP3 expression in the rat. In perinatal rats, AQP3 does not directly determine net water transport through the skin.

Contribution of aquaporin 9 and multidrug resistance-associated protein 2 to differential sensitivity to arsenite between primary cultured chorion and amnion cells prepared from human fetal membranes

International Nuclear Information System (INIS)

Yoshino, Yuta; Yuan, Bo; Kaise, Toshikazu; Takeichi, Makoto; Tanaka, Sachiko; Hirano, Toshihiko; Kroetz, Deanna L.; Toyoda, Hiroo

2011-01-01

Arsenic trioxide (arsenite, As III ) has shown a remarkable clinical efficacy, whereas its side effects are still a serious concern. Therefore, it is critical to understand the effects of As III on human-derived normal cells for revealing the mechanisms underlying these side effects. We examined the effects of As III on primary cultured chorion (C) and amnion (A) cells prepared from human fetal membranes. A significant dose-dependent As III -mediated cytotoxicity was observed in the C-cells accompanied with an increase of lactate dehydrogenase (LDH) release. Higher concentrations of As III were required for the A-cells to show cytotoxicity and LDH release, suggesting that the C-cells were more sensitive to As III than the A-cells. The expression levels of aquaporin 9 (AQP9) were approximately 2 times higher in the C-cells than those in the A-cells. Both intracellular arsenic accumulation and its cytotoxicity in the C-cells were significantly abrogated by sorbitol, a competitive AQP9 inhibitor, in a dose-dependent manner. The protein expression levels of multidrug resistance-associated protein (MRP) 2 were downregulated by As III in the C-cells, but not in the A-cells. No significant differences in the expression levels of MRP1 were observed between C- and A-cells. The protein expression of P-glycoprotein (P-gp) was hardly detected in both cells, although a detectable amount of its mRNA was observed. Cyclosporine A, a broad-spectrum inhibitor for ABC transporters, and MK571, a MRP inhibitor, but not PGP-4008, a P-gp specific inhibitor, potently sensitized both cells to As III -mediated cytotoxicity. These results suggest that AQP9 and MRP2 are involved in controlling arsenic accumulation in these normal cells, which then contribute to differential sensitivity to As III cytotoxicity between these cells. -- Highlights: ► Examination of effect of As III on primary cultured chorion (C) and amnion (A) cells. ► Dose-dependent As III -mediated cytotoxicity in C

Inhibition of HMGB1 reduces rat spinal cord astrocytic swelling and AQP4 expression after oxygen-glucose deprivation and reoxygenation via TLR4 and NF-κB signaling in an IL-6-dependent manner.

Science.gov (United States)

Sun, Lin; Li, Man; Ma, Xun; Feng, Haoyu; Song, Junlai; Lv, Cong; He, Yajun

2017-11-25

Spinal cord astrocyte swelling is an important component to spinal cord edema and is associated with poor functional recovery as well as therapeutic resistance after spinal cord injury (SCI). High mobility group box-1 (HMGB1) is a mediator of inflammatory responses in the central nervous system and plays a critical role after SCI. Given this, we sought to identify both the role and underlying mechanisms of HMGB1 in cellular swelling and aquaporin 4 (AQP4) expression in cultured rat spinal cord astrocytes after oxygen-glucose deprivation/reoxygenation (OGD/R). The post-natal day 1-2 Sprague-Dawley rat spinal cord astrocytes were cultured in vitro, and the OGD/R model was induced. We first investigated the effects of OGD/R on spinal cord astrocytic swelling and HMGB1 and AQP4 expression, as well as HMGB1 release. We then studied the effects of HMGB1 inhibition on cellular swelling, HMGB1 and AQP4 expression, and HMGB1 release. The roles of both toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway and interleukin-6 (IL-6) in reducing cellular swelling resulting from HMGB1 inhibition in spinal cord astrocytes after OGD/R were studied. Intergroup data were compared using one-way analysis of variance (ANOVA) followed by Dunnett's test. The OGD/R increased spinal cord astrocytic swelling and HMGB1 and AQP4 expression, as well as HMGB1 release. Inhibition of HMGB1 using either HMGB1 shRNA or ethyl pyruvate resulted in reduced cellular volume, mitochondrial and endoplasmic reticulum swelling, and lysosome number and decreased upregulation of both HMGB1 and AQP4 in spinal cord astrocytes, as well as HMGB1 release. The HMGB1 effects on spinal cord astrocytic swelling and AQP4 upregulation after OGD/R were mediated-at least in part-via activation of TLR4, myeloid differentiation primary response gene 88 (MyD88), and NF-κB. These activation effects can be repressed by TLR4 inhibition using CLI-095 or C34, or by NF-κB inhibition using BAY 11

Identification of the AQP members involved in abiotic stress responses from Arabidopsis.

Science.gov (United States)

Feng, Zhi-Juan; Xu, Sheng-Chun; Liu, Na; Zhang, Gu-Wen; Hu, Qi-Zan; Xu, Zhao-Shi; Gong, Ya-Ming

2018-03-10

Aquaporins (AQPs) constitute a highly diverse family of water channel proteins that play crucial biological functions in plant growth and development and stress physiology. In Arabidopsis, 35 AQPs are classified into four subfamilies (PIPs, TIPs, NIPs and SIPs). However, knowledge about the roles of different subfamily AQPs remains limited. Here, we explored the chromosomal location, gene structure and expression patterns of all AQPs in different tissues or under different abiotic stresses based on available microarray data. Tissue expression analysis showed that different AQPs had various expression patterns in tissues (root, leaf, flower and seed). Expression profiles under stress conditions revealed that most AQPs were responsive to osmotic, salt and drought stresses. Phenotypic and physiological identification showed that Tip2;2 loss-of-function mutant exhibited less sensitive to abiotic stresses (mannitol, NaCl and PEG) compared with wild-type, as evident by analysis of germination rate, root growth, survival rate, ion leakage, malondialdehyde (MDA) and proline contents. Mutant of TIP2;2 modulated the transcript levels of SOS1, SOS2, SOS3, DREB1A, DREB2A and P5CS1, under abiotic stress conditions. This study provides a basis for further functional identification of stress-related candidate AQPs in Arabidopsis. Copyright © 2017 Elsevier B.V. All rights reserved.

Repulsion between Lys258 and upstream arginines explains the missorting of the AQP2 mutant p.Glu258Lys in nephrogenic diabetes insipidus.

NARCIS (Netherlands)

Kamsteeg, E.J.; Stoffels, M.; Tamma, G.; Siemerink-Konings, I.B.M.; Deen, P.M.T.

2009-01-01

Regulation of body water homeostasis occurs by the vasopressin-dependent sorting of aquaporin-2 (AQP2) water channels to and from the apical membrane of renal principal cells. Mutations in AQP2 cause autosomal nephrogenic diabetes insipidus (NDI), a disease that renders the kidney unresponsive to

Increased occurrence of anti-AQP4 seropositivity and unique HLA Class II associations with neuromyelitis optica (NMO), among Muslim Arabs in Israel.

Science.gov (United States)

Brill, Livnat; Mandel, Micha; Karussis, Dimitrios; Petrou, Panayiota; Miller, Keren; Ben-Hur, Tamir; Karni, Arnon; Paltiel, Ora; Israel, Shoshana; Vaknin-Dembinsky, Adi

2016-04-15

Previous studies have revealed different human leukocyte antigen (HLA) associations in multiple sclerosis (MS) and neuromyelitis optica (NMO), further discriminating these two demyelinating pathological conditions. In worldwide analyses, NMO and opticospinal MS are represented at higher proportions among demyelinating conditions in African, East-Asian and Latin American populations. There are currently no data regarding the prevalence of NMO in Middle East Muslims. The population in Israel is diverse in many ways, and includes subpopulations, based on religion and ethnicity; some exhibit genetic homogeneity. In Israel, the incidence of MS is lower in the Muslim population than the Jewish population and Muslims carry different allele frequency distribution of HLA haplotypes. To evaluate the occurrence of anti-AQP4 seropositivity in the Israeli Muslim population among patients with central nervous system (CNS) demyelinating conditions; and to identify the HLA DR and DQ profiles of Muslim Arab Israeli patients with NMO spectrum of diseases (NMOSD). The prevalence of anti-AQP4 seropositivity was analyzed in 342 samples, obtained from patients with various CNS demyelinating conditions and in a validation set of 310 samples. HLA class II alleles (HLA-DRB1 and DQB1) were examined in DNA samples from 35 Israeli Muslim Arabs NMO patients and compared to available data from 74 Israeli Muslim controls. Our data reveal a significantly increased prevalence of anti-AQP4 seropositivity, indicative of NMOSD, in Muslim Arab Israeli patients with initial diagnosis of a CNS demyelinating syndrome. In this population, there was a positive association with the HLA-DRB1*04:04 and HLA-DRB1*10:01 alleles (p=0.03), and a strong negative association with the HLA-DRB1*07 and HLA-DQB1*02:02 alleles (p=0.003, p=0.002). Our findings indicate a possibly increased prevalence of NMOSD in Muslim Arabs in Israel with distinct (positive and negative) HLA associations. Further studies in patients with

Effect of the cGMP pathway on AQP2 expression and translocation: potential implications for nephrogenic diabetes insipidus.

NARCIS (Netherlands)

Boone, M.; Kortenoeven, M.L.A.; Robben, J.H.; Deen, P.M.T.

2010-01-01

BACKGROUND: Arginine vasopressin (AVP) binding to the V2 receptor (V2R) in renal collecting duct principal cells induces a cAMP signalling cascade resulting in the activation of protein kinase A (PKA), translocation of aquaporin-2 (AQP2) to the apical membrane and an increase in AQP2 expression.

Contribution of aquaporin 9 and multidrug resistance-associated protein 2 to differential sensitivity to arsenite between primary cultured chorion and amnion cells prepared from human fetal membranes

Energy Technology Data Exchange (ETDEWEB)

Yoshino, Yuta [Department of Clinical Molecular Genetics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Yuan, Bo, E-mail: yuanbo@toyaku.ac.jp [Department of Clinical Molecular Genetics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, 1550 4th St, RH584E Box 2911 San Francisco, CA 94158-2911 (United States); Kaise, Toshikazu [Laboratory of Environmental Chemodynamics, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Takeichi, Makoto [Yoneyama Maternity Hospital, 2-12 Shin-machi, Hachioji, Tokyo 192-0065 (Japan); Tanaka, Sachiko; Hirano, Toshihiko [Department of Clinical Pharmacology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Kroetz, Deanna L. [Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, 1550 4th St, RH584E Box 2911 San Francisco, CA 94158-2911 (United States); Toyoda, Hiroo [Department of Clinical Molecular Genetics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan)

2011-12-15

Arsenic trioxide (arsenite, As{sup III}) has shown a remarkable clinical efficacy, whereas its side effects are still a serious concern. Therefore, it is critical to understand the effects of As{sup III} on human-derived normal cells for revealing the mechanisms underlying these side effects. We examined the effects of As{sup III} on primary cultured chorion (C) and amnion (A) cells prepared from human fetal membranes. A significant dose-dependent As{sup III}-mediated cytotoxicity was observed in the C-cells accompanied with an increase of lactate dehydrogenase (LDH) release. Higher concentrations of As{sup III} were required for the A-cells to show cytotoxicity and LDH release, suggesting that the C-cells were more sensitive to As{sup III} than the A-cells. The expression levels of aquaporin 9 (AQP9) were approximately 2 times higher in the C-cells than those in the A-cells. Both intracellular arsenic accumulation and its cytotoxicity in the C-cells were significantly abrogated by sorbitol, a competitive AQP9 inhibitor, in a dose-dependent manner. The protein expression levels of multidrug resistance-associated protein (MRP) 2 were downregulated by As{sup III} in the C-cells, but not in the A-cells. No significant differences in the expression levels of MRP1 were observed between C- and A-cells. The protein expression of P-glycoprotein (P-gp) was hardly detected in both cells, although a detectable amount of its mRNA was observed. Cyclosporine A, a broad-spectrum inhibitor for ABC transporters, and MK571, a MRP inhibitor, but not PGP-4008, a P-gp specific inhibitor, potently sensitized both cells to As{sup III}-mediated cytotoxicity. These results suggest that AQP9 and MRP2 are involved in controlling arsenic accumulation in these normal cells, which then contribute to differential sensitivity to As{sup III} cytotoxicity between these cells. -- Highlights: Black-Right-Pointing-Pointer Examination of effect of As{sup III} on primary cultured chorion (C) and amnion

Metabolomics reveals distinct, antibody-independent, molecular signatures of MS, AQP4-antibody and MOG-antibody disease.

Science.gov (United States)

Jurynczyk, Maciej; Probert, Fay; Yeo, Tianrong; Tackley, George; Claridge, Tim D W; Cavey, Ana; Woodhall, Mark R; Arora, Siddharth; Winkler, Torsten; Schiffer, Eric; Vincent, Angela; DeLuca, Gabriele; Sibson, Nicola R; Isabel Leite, M; Waters, Patrick; Anthony, Daniel C; Palace, Jacqueline

2017-12-06

The overlapping clinical features of relapsing remitting multiple sclerosis (RRMS), aquaporin-4 (AQP4)-antibody (Ab) neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein (MOG)-Ab disease mean that detection of disease specific serum antibodies is the gold standard in diagnostics. However, antibody levels are not prognostic and may become undetectable after treatment or during remission. Therefore, there is still a need to discover antibody-independent biomarkers. We sought to discover whether plasma metabolic profiling could provide biomarkers of these three diseases and explore if the metabolic differences are independent of antibody titre. Plasma samples from 108 patients (34 RRMS, 54 AQP4-Ab NMOSD, and 20 MOG-Ab disease) were analysed by nuclear magnetic resonance spectroscopy followed by lipoprotein profiling. Orthogonal partial-least squares discriminatory analysis (OPLS-DA) was used to identify significant differences in the plasma metabolite concentrations and produce models (mathematical algorithms) capable of identifying these diseases. In all instances, the models were highly discriminatory, with a distinct metabolite pattern identified for each disease. In addition, OPLS-DA identified AQP4-Ab NMOSD patient samples with low/undetectable antibody levels with an accuracy of 92%. The AQP4-Ab NMOSD metabolic profile was characterised by decreased levels of scyllo-inositol and small high density lipoprotein particles along with an increase in large low density lipoprotein particles relative to both RRMS and MOG-Ab disease. RRMS plasma exhibited increased histidine and glucose, along with decreased lactate, alanine, and large high density lipoproteins while MOG-Ab disease plasma was defined by increases in formate and leucine coupled with decreased myo-inositol. Despite overlap in clinical measures in these three diseases, the distinct plasma metabolic patterns support their distinct serological profiles and confirm that these

New Perspectives on the Potential Role of Aquaporins (AQPs in the Physiology of Inflammation

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Rosaria Meli

2018-02-01

Full Text Available Aquaporins (AQPs are emerging, in the last few decades, as critical proteins regulating water fluid homeostasis in cells involved in inflammation. AQPs represent a family of ubiquitous membrane channels that regulate osmotically water flux in various tissues and sometimes the transport of small solutes, including glycerol. Extensive data indicate that AQPs, working as water channel proteins, regulate not only cell migration, but also common events essential for inflammatory response. The involvement of AQPs in several inflammatory processes, as demonstrated by their dysregulation both in human and animal diseases, identifies their new role in protection and response to different noxious stimuli, including bacterial infection. This contribution could represent a new key to clarify the dilemma of host-pathogen communications, and opens up new scenarios regarding the investigation of the modulation of specific AQPs, as target for new pharmacological therapies. This review provides updated information on the underlying mechanisms of AQPs in the regulation of inflammatory responses in mammals and discusses the broad spectrum of options that can be tailored for different diseases and their pharmacological treatment.

Decreased Expression of Na+/K+-ATPase, NHE3, NBC1, AQP1 and OAT in Gentamicin-induced Nephropathy

Science.gov (United States)

Bae, Woo Kyun; Lee, JongUn; Park, Jeong Woo; Bae, Eun Hui; Ma, Seong Kwon; Kim, Suhn Hee

2008-01-01

The present study was aimed to determine whether there is an altered regulation of tubular transporters in gentamicin-induced nephropathy. Sprague-Dawley male rats (200~250 g) were subcutaneously injected with gentamicin (100 mg/kg per day) for 7 days, and the expression of tubular transporters was determined by immunoblotting and immunohistochemistry. The mRNA and protein expression of OAT was also determined. Gentamicin-treated rats exhibited significantly decreased creatinine clearance along with increased plasma creatinine levels. Accordingly, the fractional excretion of sodium increased. Urine volume was increased, while urine osmolality and free water reabsorption were decreased. Immunoblotting and immunohistochemistry revealed decreased expression of Na+/K+-ATPase, NHE3, NBC1, and AQP1 in the kidney of gentamicin-treated rats. The expression of OAT1 and OAT3 was also decreased. Gentamicin-induced nephropathy may at least in part be causally related with a decreased expression of Na+/K+-ATPase, NHE3, NBC1, AQP1 and OAT. PMID:19967075

A new AQP1 null allele identified in a Gypsy woman who developed an anti-CO3 during her first pregnancy.

Science.gov (United States)

Saison, C; Peyrard, T; Landre, C; Ballif, B A; Schlosser, K A; Dettori, I; Chicheportiche, C; Nemeth, P; Cartron, J-P; Arnaud, L

2012-08-01

The Colton blood group antigens are carried by the AQP1 water channel. AQP1(-/-) individuals, also known as Colton-null since they express no Colton antigens, do not suffer any apparent clinical consequence but may develop a clinically significant alloantibody (anti-CO3) induced by transfusion or pregnancy. Identification and transfusion support of Colton-null patients are highly challenging, not only due to the extreme rarity of this phenotype, the lack of appropriate reagents in most laboratories, as well as the possibility of confusing it with the recently described CO:-1,-2,3,-4 phenotype where AQP1 is present. This study investigated a new Colton-null case and evaluated three commercially available anti-AQP1s to identify Colton-null red blood cell samples. The Colton-null phenotype was investigated by standard serological techniques, AQP1 sequencing, immunoblot and flow cytometry analyses. We identified and characterized the Colton-null phenotype in a Gypsy woman who developed an anti-CO3 during her first pregnancy. After developing a simple and robust method to sequence AQP1, we showed that she was apparently homozygous for a new AQP1 null allele, AQP1 601delG, whose product is not expressed in her red blood cells. We also established the Colton specificity of three commercially available anti-AQP1s in immunoblot and/or flow cytometry analyses. This Gypsy woman represents the sixth Colton-null case characterized at the serological, genetic and biochemical levels. The validation here of new reagents and methods should facilitate the identification of Colton-null individuals. © 2012 The Author(s). Vox Sanguinis © 2012 International Society of Blood Transfusion.

Effects of Cetuximab Combined with Celecoxib on Apoptosis and KDR and AQP1 
Expression in Lung Cancer

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Honggang XIA

2013-12-01

Full Text Available Background and objective Neoadjuvant chemotherapy is a new development in the treatment of lung cancer. In recent years, cetuximab and celecoxib have been commonly used in this procedure. This study aims to explore the effect of cetuximab combined with celecoxib on apoptosis and KDR and AQP1 expression in lung cancer A549 cells. Method The cells were cultured in RPMI-1640 and then divided into four groups: control group, 1 nmol/L cetuximab group, 25 µmol/L celecoxib group, and 1 nmol/L cetuximab+25 µmol/L celecoxib group. The treatment time was 48 h. The mRNA and protein expression levels of KDR and AQP1 were detected by RT-PCR and Western blot, respectively. The apoptosis, proliferation, and invasive ability of A549 cells before and after transfection were examined using flow cytometry, MTT, and transwell methods. Results Cetuximab and celecoxib inhibited the growth of A549 cells in a dose-dependent manner. Their combination produced a greater growth inhibition than when either was used alone (P<0.01. Cetuximab and celecoxib both induced the apoptosis of A549 cells, and their combination produced a higher apoptosis rate (P<0.01. Cetuximab in combination with celecoxib also induced G1 phase arrest and downregulated the expression of KDR and AQP1 in A549 cells (P<0.05. As a result, the invasion ability of the A549 cells was significantly decreased. Conclusion Cetuximab in combination with celecoxib can synergistically inhibit the growth of A549 cells and downregulate the expression of KDR and AQP1 in A549 cells. The combination of cetuximab and celecoxib is a potential strategy for lung cancer therapy.

Molecular cloning and expression analysis of the aqp1aa gene in half-smooth tongue sole (Cynoglossus semilaevis.

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Hua Guo

Full Text Available Aquaporin 1 (AQP1 is a member of the transmembrane water channel family of proteins with special structural features, and two AQP1 paralogous genes (aqp1aa and aqp1ab are reported in teleosts. In the present study, the aqp1aa gene of half-smooth tongue sole (Cynoglossus semilaevis was cloned and characterized. The full-length cDNA of aqp1aa is 1411 bp with a 786 bp open reading frame encoding a 261-amino acid putative protein with a characteristic structure consisting of 6 membrane-spanning α-helical domains and two highly conserved asparagine-proline-alanine motifs. Real-time quantitative PCR revealed that aqp1aa mRNA is expressed predominantly in the testis of males and pseudo-males, while its expression is low in the ovary and lowest in doublesex and mab-3-related transcription factor 1(DMRT1 knock out fish and triploid males. In situ hybridization indicated that aqp1aa mRNA is expressed mainly in the germ cells of males and pseudo-males, especially in spermatozoa and spermatids. These results suggest that the aqp1aa may play a role in spermatogenesis of C. semilaevis.

Autoantibody-induced internalization of CNS AQP4 water channel and EAAT2 glutamate transporter requires astrocytic Fc receptor.

Science.gov (United States)

Hinson, Shannon R; Clift, Ian C; Luo, Ningling; Kryzer, Thomas J; Lennon, Vanda A

2017-05-23

Aquaporin-4 (AQP4) water channel-specific IgG distinguishes neuromyelitis optica (NMO) from multiple sclerosis and causes characteristic immunopathology in which central nervous system (CNS) demyelination is secondary. Early events initiating the pathophysiological outcomes of IgG binding to astrocytic AQP4 are poorly understood. CNS lesions reflect events documented in vitro following IgG interaction with AQP4: AQP4 internalization, attenuated glutamate uptake, intramyelinic edema, interleukin-6 release, complement activation, inflammatory cell recruitment, and demyelination. Here, we demonstrate that AQP4 internalization requires AQP4-bound IgG to engage an astrocytic Fcγ receptor (FcγR). IgG-lacking Fc redistributes AQP4 within the plasma membrane and induces interleukin-6 release. However, AQP4 endocytosis requires an activating FcγR's gamma subunit and involves astrocytic membrane loss of an inhibitory FcγR, CD32B. Interaction of the IgG-AQP4 complex with FcγRs triggers coendocytosis of the excitatory amino acid transporter 2 (EAAT2). Requirement of FcγR engagement for internalization of two astrocytic membrane proteins critical to CNS homeostasis identifies a complement-independent, upstream target for potential early therapeutic intervention in NMO.

Expression of aquaporin-7 and aquaporin-9 in tanycyte cells and choroid plexus during mouse estrus cycle.

Science.gov (United States)

Yaba, A; Sozen, B; Suzen, B; Demir, N

2017-03-01

Tanycytes are special ependymal cells located in the ventrolateral wall and floor of the third ventricle having processes extending nuclei that regulate reproductive functions and around of vessels in median eminance. The aquaporins (AQPs) are a family of transmembrane proteins that transport water and glycerol. AQP-7 and -9 are permeable to other small molecules as glycerol and therefore called aquaglyceroporins. In this study, we aimed to show localization of AQP-7 and -9 in epithelial cells of choroid plexus and tanycytes during female mouse estrus cycle. AQP-7 and -9 proteins were detected in α2 and β1 tanycytes in prœstrus stage. Interestingly, there is no staining in estrus stage in any type of tanycytes. We observed weak immunoreactivity in α1, α2 and β1 tanycyte cells in metestrus stage for AQP-7 and α1 for AQP-9 protein. AQP-7 and -9 showed intense immunoreactivity in α2, β1 and β2 tanycyte cells during diestrus stage. Consequently, AQP-7 and -9 showed differential staining pattern in different stages of mouse estrus cycle. In the light of our findings and other recent publications, we suggest that AQP-7 and -9-mediated glycerol transport in tanycyte cells might be under hormonal control to use glycerol as a potential energy substrate during mouse estrus cycle. Copyright © 2016. Published by Elsevier Masson SAS.

Long-term aldosterone treatment induces decreased apical but increased basolateral expression of AQP2 in CCD of rat kidney.

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Seigneux, S. de; Nielsen, J.; Olesen, E.T.; Dimke, H.; Kwon, T.H.; Frokiaer, J.; Nielsen, S.

2007-01-01

The purpose of the present studies was to determine the effects of high-dose aldosterone and dDAVP treatment on renal aquaporin-2 (AQP2) regulation and urinary concentration. Rats were treated for 6 days with either vehicle (CON; n = 8), dDAVP (0.5 ng/h, dDAVP, n = 10), aldosterone (Aldo, 150

Aliskiren increases aquaporin-2 expression and attenuates lithium-induced nephrogenic diabetes insipidus.

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Lin, Yu; Zhang, Tiezheng; Feng, Pinning; Qiu, Miaojuan; Liu, Qiaojuan; Li, Suchun; Zheng, Peili; Kong, Yonglun; Levi, Moshe; Li, Chunling; Wang, Weidong

2017-10-01

The direct renin inhibitor aliskiren has been shown to be retained and persist in medullary collecting ducts even after treatment is discontinued, suggesting a new mechanism of action for this drug. The purpose of the present study was to investigate whether aliskiren regulates renal aquaporin expression in the collecting ducts and improves urinary concentrating defect induced by lithium in mice. The mice were fed with either normal chow or LiCl diet (40 mmol·kg dry food -1 ·day -1 for 4 days and 20 mmol·kg dry food -1 ·day -1 for the last 3 days) for 7 days. Some mice were intraperitoneally injected with aliskiren (50 mg·kg body wt -1 ·day -1 in saline). Aliskiren significantly increased protein abundance of aquaporin-2 (AQP2) in the kidney inner medulla in mice. In inner medulla collecting duct cell suspension, aliskiren markedly increased AQP2 and phosphorylated AQP2 at serine 256 (pS256-AQP2) protein abundance, which was significantly inhibited both by adenylyl cyclase inhibitor MDL-12330A and by PKA inhibitor H89, indicating an involvement of the cAMP-PKA signaling pathway in aliskiren-induced increased AQP2 expression. Aliskiren treatment improved urinary concentrating defect in lithium-treated mice and partially prevented the decrease of AQP2 and pS256-AQP2 protein abundance in the inner medulla of the kidney. In conclusion, the direct renin inhibitor aliskiren upregulates AQP2 protein expression in inner medullary collecting duct principal cells and prevents lithium-induced nephrogenic diabetes insipidus likely via cAMP-PKA pathways. Copyright © 2017 the American Physiological Society.

[Impacts of the formula of Suoquanwan(SQW) on expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney of rat polyuria model of Yang-deficiency].

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Cao, Hong-Ying; Wu, Qing-He; Huang, Ping; He, Jin-Yang

2009-06-01

To observe the impacts of the formula of Suoquanwan (SQW) on the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney of rat polyuria model of Yang-deficiency. The model rats were induced by adenine (250 mg/kg) for 4 weeks, then treated respectively with SQW or dDAVP. The expression of AQP-2 mRNA and AVPR-V2 mRNA in kidney of Yang-deficiency model by realtime fluorescence quantitative PCR method were investigated. In model rats, the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney decreased, dDAVP and SQW high dose could increased the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney. The others had no influence on the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney. SQW can increase the expression of AQP-2 mRNA and AVPR-V2 mRNA in the kidney of rat polyuria model of Yang-deficiency.

Endocrinopathies in paediatric-onset neuromyelitis optica spectrum disorder with aquaporin 4 (AQP4) antibody.

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Hacohen, Yael; Messina, Silvia; Gan, Hoong-Wei; Wright, Sukhvir; Chandratre, Saleel; Leite, Maria Isabel; Fallon, Penny; Vincent, Angela; Ciccarelli, Olga; Wassmer, Evangeline; Lim, Ming; Palace, Jacqueline; Hemingway, Cheryl

2018-04-01

The involvement of the diencephalic regions in neuromyelitis optica spectrum disorder (NMOSD) may lead to endocrinopathies. In this study, we identified the following endocrinopathies in 60% (15/25) of young people with paediatric-onset aquaporin 4-Antibody (AQP4-Ab) NMOSD: morbid obesity ( n = 8), hyperinsulinaemia ( n = 5), hyperandrogenism ( n = 5), amenorrhoea ( n = 5), hyponatraemia ( n = 4), short stature ( n = 3) and central hypothyroidism ( n = 2) irrespective of hypothalamic lesions. Morbid obesity was seen in 88% (7/8) of children of Caribbean origin. As endocrinopathies were prevalent in the majority of paediatric-onset AQP4-Ab NMOSD, endocrine surveillance and in particular early aggressive weight management is required for patients with AQP4-Ab NMOSD.

Involvement of TRPV1 and AQP2 in hypertonic stress by xylitol in odontoblast cells.

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Tokuda, M; Fujisawa, M; Miyashita, K; Kawakami, Y; Morimoto-Yamashita, Y; Torii, M

2015-02-01

To examine the responses of mouse odontoblast-lineage cell line (OLC) cultures to xylitol-induced hypertonic stress. OLCs were treated with xylitol, sucrose, sorbitol, mannitol, arabinose and lyxose. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. The expression of transient receptor potential vanilloids (TRPV) 1, 3 and 4 was detected using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The expression of aquaporin (AQP) 2 was detected using immunofluorescence and Western blotting analysis. The expression of interleukin-6 (IL-6) under xylitol-induced hypertonic stress was assessed using an enzyme-linked immunosorbent assay (ELISA). Small interfering ribonucleic acid (siRNA) for AQP-2 was used to inhibition assay. Xylitol-induced hypertonic stress did not decrease OLC viability, unlike the other sugars tested. OLCs expressed TRPV1, 3 and 4 as well as AQP2. Xylitol inhibited lipopolysaccharide (LPS)-induced IL-6 expression after 3 h of hypertonic stress. TRPV1 mRNA expression was upregulated by xylitol. Costimulation with HgCl2 (AQP inhibitor) and Ruthenium red (TRPV1 inhibitor) decreased cell viability with xylitol stimulation. OLCs treated with siRNA against TRPV1 exhibited decreased cell viability with xylitol stimulation. OLCs have high-cell viability under xylitol-induced hypertonic stress, which may be associated with TRPV1 and AQP2 expressions.

Effects of post-conditioning with sevoflurane on the expressions of intestinal AQP8 and I-FABP in pigs with hemorrhagic shock

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Yan-hong CHEN

2015-11-01

Full Text Available Objective　To observe the effects of sevoflurane post-conditioning on the expression of Aquaporin 8 (AQP8 and intestinal fatty acid binding protein (I-FABP, in order to investigate the protective role of sevoflurane post-conditioning on intestinal injury and its underlying mechanism. Methods　Eighteen bama miniature pigs were randomly divided into three groups (6 each using a random number table: control group (S group, hemorrhagic shock group (HS group, and sevoflurane post-coditioning group (Post/ Sev group. Experimental animals were fasted for 8 hours before surgery, and propofol 3mg/kg was given viathe ear vein. Endotracheal intubation was done when the animal fell asleep. Bloodletting from the femoral artery after anesthesia was done to reproduce hemorrhagic shock. In Post/Sev group, 2% sevoflurane was given by inhalation for 30min (post-conditioning after successful reproduction of the model. Blood samples were collected prior to anesthesia (T0 and 30min (T1, 1h (T2, 1.5h (T3, 2h (T4, 3h (T5, 4h (T6 after hemorrhagic shock. The quantity of blood I-FABP and intestinal AQP8 levels were determined with ELISA. Water content in the intestinal tissue was determined by wet and dry weight method. Histopathological changes in the intestinal tissue were observed with HE staining. Results　Compared with the control group, the serum I-FABP content, the expressions of intestinal AQP8, and water content in the intestinal tissue were significantly increased in HS group and Post/Sev (P<0.05 group. Compared with HS group, the above indices in Post/Sev group were significantly lower (P<0.05. These results were confirmed by pathological examination. Conclusion　Postconditioning with sevoflurane could improve, to some extent, pig's intestinal barrier function in hemorrhagic shock, and this effect is likely related with lowering of intestinal AQP8 and I-FABP expression and mucosal edema. DOI: 10.11855/j.issn.0577-7402.2015.11.11

Pituitary Gonadotropins, Prolactin and Growth Hormone Differentially Regulate AQP1 Expression in the Porcine Ovarian Follicular Cells

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Mariusz T. Skowronski

2017-12-01

Full Text Available The present in vitro study analyzed whether the hormones that affect the ovarian follicular steroidogenesis process also participate in the regulation of AQP1 mRNA and protein expression. Granulosa (Gc and theca cells (Tc of medium and large porcine ovarian follicles were exposed to follicle-stimulating hormone (FSH, luteinizing hormone (LH, prolactin (PRL and growth hormone (GH for 24 h in separated cells and co-cultures of these cells. Real-time PCR, Western blotting, immunofluorescence and volumetric analysis were then performed. Gonadotropins, PRL and GH had a stimulatory impact on AQP1 mRNA and protein expression in Gc and Tc of medium and large ovarian cells. Moreover, swelling assays, in response to a hypotonic environment, demonstrated the functional presence of AQPs in porcine Gc and Tc. Immunofluorescence analysis showed that AQP1 protein was mainly localized in the perinuclear region of the cytoplasm, endosomes and cell membranes of Gc and Tc from medium and large follicles. It seems possible that AQP1 present in Gc and Tc cells may be implicated not only in the regulation of water homeostasis required for follicle development but also in cell proliferation and migration.

Fluxes of water through aquaporin 9 weaken membrane-cytoskeleton anchorage and promote formation of membrane protrusions.

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Thommie Karlsson

Full Text Available All modes of cell migration require rapid rearrangements of cell shape, allowing the cell to navigate within narrow spaces in an extracellular matrix. Thus, a highly flexible membrane and a dynamic cytoskeleton are crucial for rapid cell migration. Cytoskeleton dynamics and tension also play instrumental roles in the formation of different specialized cell membrane protrusions, viz. lamellipodia, filopodia, and membrane blebs. The flux of water through membrane-anchored water channels, known as aquaporins (AQPs has recently been implicated in the regulation of cell motility, and here we provide novel evidence for the role of AQP9 in the development of various forms of membrane protrusion. Using multiple imaging techniques and cellular models we show that: (i AQP9 induced and accumulated in filopodia, (ii AQP9-associated filopodial extensions preceded actin polymerization, which was in turn crucial for their stability and dynamics, and (iii minute, local reductions in osmolarity immediately initiated small dynamic bleb-like protrusions, the size of which correlated with the reduction in osmotic pressure. Based on this, we present a model for AQP9-induced membrane protrusion, where the interplay of water fluxes through AQP9 and actin dynamics regulate the cellular protrusive and motile activity of cells.

The underlying physiological basis of the desert rodent Meriones shawi's survival to prolonged water deprivation: Central vasopressin regulation on peripheral kidney water channels AQPs-2.

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Elgot, A; El Hiba, O; Belkouch, M; Gamrani, H

2018-02-01

Meriones shawi (M. shawi) is a particular semi-desert rodent known by its resistance to long periods of thirst. The aim of the present investigation is to clarify the underlying mechanisms allowing M. shawi to resist to hard conditions of dehydration. For this reason we used two different approaches: i) a morphometric study, which consists in measuring the effect of dehydration on body and kidneys weights as well as the report kidney weight/body weight, ii) By immunohistochemistry, we proceed to study the effect of dehydration on the immunoreactivity of central vasopressin (AVP) and the kidney aquaporin-2 (AQP-2) which is a channel protein that allows water to permeate across cell membranes. Our results showed both a body mass decrease accompanied by a remarkable kidneys hypertrophy. The immunohistochemical study showed a significant increase of AQP-2 immunoreactivity in the medullar part of Meriones kidneys allowing probably to Meriones a great ability to water retention. Consistently, we demonstrate that the increased AQP-2 expression occurred together with an increase in vasopressin (AVP) expression in both hypothalamic supraoptic (SON) and paraventricular nucleus (PVN), which are a major hub in the osmotic control circuitry. These various changes seen either in body weight and kidneys or at the cellular level might be the basis of peripheral control of body water homeostasis, providing to M. shawia strong resistance against chronic dehydration. Copyright © 2017 Elsevier GmbH. All rights reserved.

The aquaporin TcAQP1 of the desert truffle Terfezia claveryi is a membrane pore for water and CO(2) transport.

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Navarro-Ródenas, Alfonso; Ruíz-Lozano, Juan Manuel; Kaldenhoff, Ralf; Morte, Asunción

2012-02-01

Terfezia claveryi is a hypogeous mycorrhizal fungus belonging to the so-called "desert truffles," with a good record as an edible fungus and of considerable economic importance. T. claveryi improves the tolerance to water stress of the host plant Helianthemum almeriense, for which, in field conditions, symbiosis with T. claveryi is valuable for its survival. We have characterized cDNAs from T. claveryi and identified a sequence related to the aquaporin gene family. The full-length sequence was obtained by rapid amplification of cDNA ends and was named TcAQP1. This aquaporin gene encoded a functional water-channel protein, as demonstrated by heterologous expression assays in Saccharomyces cerevisiae. The mycorrhizal fungal aquaporin increased both water and CO(2) conductivity in the heterologous expression system. The expression patterns of the TcAQP1 gene in mycelium, under different water potentials, and in mycorrhizal plants are discussed. The high levels of water conductivity of TcAQP1 could be related to the adaptation of this mycorrhizal fungus to semiarid areas. The CO(2) permeability of TcAQP1 could be involved in the regulation of T. claveryi growth during presymbiotic phases, making it a good candidate to be considered a novel molecular signaling channel in mycorrhizal fungi.

Single amino acids in the carboxyl terminal domain of aquaporin-1 contribute to cGMP-dependent ion channel activation

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Yool Andrea J

2003-10-01

Full Text Available Abstract Background Aquaporin-1 (AQP1 functions as an osmotic water channel and a gated cation channel. Activation of the AQP1 ion conductance by intracellular cGMP was hypothesized to involve the carboxyl (C- terminus, based on amino acid sequence alignments with cyclic-nucleotide-gated channels and cGMP-selective phosphodiesterases. Results Voltage clamp analyses of human AQP1 channels expressed in Xenopus oocytes demonstrated that the nitric oxide donor, sodium nitroprusside (SNP; 3–14 mM activated the ionic conductance response in a dose-dependent manner. Block of soluble guanylate cyclase prevented the response. Enzyme immunoassays confirmed a linear dose-dependent relationship between SNP and the resulting intracellular cGMP levels (up to 1700 fmol cGMP /oocyte at 14 mM SNP. Results here are the first to show that the efficacy of ion channel activation is decreased by mutations of AQP1 at conserved residues in the C-terminal domain (aspartate D237 and lysine K243. Conclusions These data support the idea that the limited amino acid sequence similarities found between three diverse classes of cGMP-binding proteins are significant to the function of AQP1 as a cGMP-gated ion channel, and provide direct evidence for the involvement of the AQP1 C-terminal domain in cGMP-mediated ion channel activation.

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

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

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

Species-Specific Antimonial Sensitivity in Leishmania Is Driven by Post-Transcriptional Regulation of AQP1

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Mandal, Goutam; Mandal, Srotoswati; Sharma, Mansi; Charret, Karen Santos; Papadopoulou, Barbara; Bhattacharjee, Hiranmoy; Mukhopadhyay, Rita

2015-01-01

Leishmania is a digenetic protozoan parasite causing leishmaniasis in humans. The different clinical forms of leishmaniasis are caused by more than twenty species of Leishmania that are transmitted by nearly thirty species of phlebotomine sand flies. Pentavalent antimonials (such as Pentostam or Glucantime) are the first line drugs for treating leishmaniasis. Recent studies suggest that pentavalent antimony (Sb(V)) acts as a pro-drug, which is converted to the more active trivalent form (Sb(III)). However, sensitivity to trivalent antimony varies among different Leishmania species. In general, Leishmania species causing cutaneous leishmaniasis (CL) are more sensitive to Sb(III) than the species responsible for visceral leishmaniasis (VL). Leishmania aquaglyceroporin (AQP1) facilitates the adventitious passage of antimonite down a concentration gradient. In this study, we show that Leishmania species causing CL accumulate more antimonite, and therefore exhibit higher sensitivity to antimonials, than the species responsible for VL. This species-specific differential sensitivity to antimonite is directly proportional to the expression levels of AQP1 mRNA. We show that the stability of AQP1 mRNA in different Leishmania species is regulated by their respective 3’-untranslated regions. The differential regulation of AQP1 mRNA explains the distinct antimonial sensitivity of each species. PMID:25714343

Effects of total glucosides of peony on AQP-5 and its mRNA expression in submandibular glands of NOD mice with Sjogren's syndrome.

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Wu, G-L; Pu, X-H; Yu, G-Y; Li, T-Y

2015-01-01

The aim of this study was to observe the effects of total glucosides of peony (TGP) on pathological change, Aquaporin-5 (AQP-5) and its mRNA expression in submandibular glands of non-obese diabetic (NOD) mice with Sjogren's Syndrome, to investigate its regulation on secretion of salivary glands. 40 NOD mice were randomly divided into model group, TGP group, hydroxychloroquine group, combination group (n = 10). For TGP group, the mice were intragastrically administrated with 0.4 ml TGP dilution per day in accordance with 300 g/kg dose; for hydroxychloroquine group, the mice were intragastrically administrated with 0.4 ml hydroxychloroquine per day in accordance with 60 mg/kg dose; for the combination group, the mice were intragastrically administrated with 0.4 ml TGP dilution and 0.4 ml hydroxychloroquine. 8 weeks later, the mice were sacrificed, and submandibular glands were collected by anatomy. Pathological changes of submandibular gland were observed under a light microscope; AQP-5 protein in submandibular glands was detected by immunohistochemical staining; and AQP-5 mRNA expression in submandibular glands was detected by RT-PCR. The lymphocytic infiltration score of model mice was significantly higher than that of other groups. The pathological morphology and score of NOD mice were significantly improved after administration, and the combination group was superior to the hydroxychloroquine group and TGP group (p TGP group and the combination group were higher than the hydroxychloroquine group (p TGP may improve pathological damage of submandibular glands of NOD mouse with Sjogren's syndrome by upregulating AQP-5 and its mRNA expression in submandibular glands.

Elevated cAMP increases aquaporin-3 plasma membrane diffusion

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Marlar, Saw; Christensen, Eva Arnspang; Koffman, Jennifer Skaarup

2014-01-01

be short-term regulated via changes in protein-protein interactions, incorporation into lipid rafts, and/or changes in steady-state turnover, which could result in changes in the diffusion behavior of AQP3. Thus we measured AQP3 diffusion coefficients upon stimulation with the AVP mimic forskolin to reveal...... if AQP3 could be short-term regulated by AVP. k-Space image correlation spectroscopy (kICS) analysis of time-lapse image sequences of basolateral enhanced green fluorescent protein-tagged AQP3 (AQP3-EGFP) revealed that the forskolin-mediated elevation of cAMP increased the diffusion coefficient by 58...

Hydrocephalus induces dynamic spatiotemporal regulation of aquaporin-4 expression in the rat brain

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Praetorius Jeppe

2010-11-01

Full Text Available Abstract Background The water channel protein aquaporin-4 (AQP4 is reported to be of possible major importance for accessory cerebrospinal fluid (CSF circulation pathways. We hypothesized that changes in AQP4 expression in specific brain regions correspond to the severity and duration of hydrocephalus. Methods Hydrocephalus was induced in adult rats (~8 weeks by intracisternal kaolin injection and evaluated after two days, one week and two weeks. Using magnetic resonance imaging (MRI we quantified lateral ventricular volume, water diffusion and blood-brain barrier properties in hydrocephalic and control animals. The brains were analysed for AQP4 density by western blotting and localisation by immunohistochemistry. Double fluorescence labelling was used to study cell specific origin of AQP4. Results Lateral ventricular volume was significantly increased over control at all time points after induction and the periventricular apparent diffusion coefficient (ADC value significantly increased after one and two weeks of hydrocephalus. Relative AQP4 density was significantly decreased in both cortex and periventricular region after two days and normalized after one week. After two weeks, periventricular AQP4 expression was significantly increased. Relative periventricular AQP4 density was significantly correlated to lateral ventricular volume. AQP4 immunohistochemical analysis demonstrated the morphological expression pattern of AQP4 in hydrocephalus in astrocytes and ventricular ependyma. AQP4 co-localized with astrocytic glial fibrillary acidic protein (GFAP in glia limitans. In vascular structures, AQP4 co-localized to astroglia but not to microglia or endothelial cells. Conclusions AQP4 levels are significantly altered in a time and region dependent manner in kaolin-induced hydrocephalus. The presented data suggest that AQP4 could play an important neurodefensive role, and may be a promising future pharmaceutical target in hydrocephalus and CSF

Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

Institute of Scientific and Technical Information of China (English)

HU Hua; YAO Hong-tian; ZHANG Wei-ping; ZHANG LEI; DING Wei; ZHANG Shi-hong; CHEN Zhong; WEI Er-qing

2005-01-01

Objective: To characterize the expression of aquaporin-4 (AQP4), one of the aquaporins (AQPs), in human brain specimens from patients with traumatic brain injury or brain tumors. Methods: Nineteen human brain specimens were obtained from the patients with traumatic brain injury, brain tumors, benign meningioma or early stage hemorrhagic stroke. MRI or CT imaging was used to assess brain edema. Hematoxylin and eosin staining were used to evaluate cell damage. Immunohistochemistry was used to detect the AQP4 expression. Results: AQP4 expression was increased from 15h to at least 8 d after injury. AQP4immunoreactivity was strong around astrocytomas, ganglioglioma and metastatic adenocarcinoma. However, AQP4 immunoreactivity was only found in the centers of astrocytomas and ganglioglioma, but not in metastatic adenocarcinoma derived from lung.Conclusion: AQP4 expression increases in human brains after traumatic brain injury, within brain-derived tumors, and around brain tumors.

Comparison of spontaneous brain activity revealed by regional homogeneity in AQP4-IgG neuromyelitis optica-optic neuritis versus MOG-IgG optic neuritis patients: a resting-state functional MRI study

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Wang J

2017-10-01

Full Text Available Junqing Wang,1,* Yuan Tian,2,* Yi Shao,3,* Hui Feng,1 Limin Qin,1 Weiwei Xu,1 Hongjuan Liu,1 Quangang Xu,1 Shihui Wei,1 Lin Ma2 1Department of Ophthalmology, 2Department of Radiology, Chinese PLA General Hospital, Beijing, 3Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China *These authors contributed equally to this work Objective: Many previous studies have demonstrated that neuromyelitis optica (NMO patients have abnormalities of brain anatomy and function. However, differences in spontaneous brain activity between myelin oligodendrocyte glycoprotein (MOG-IgG ON and aquaporin 4(AQP4-neuromyelitis optica-optic neuritis (ON remain unknown. In the current study, we investigated the brain neural homogeneity in MOG-IgG ON versus AQP4-IgG NMO-ON subjects by regional homogeneity (ReHo method using magnetic resonance imaging (MRI. Patients and methods: A total of 32 NMO-ON and ON subjects (21 with AQP4-IgG+NMO-ON and 11 with MOG-IgG+ON and 34 healthy controls (HCs closely matched for age were recruited, and scans were performed for all subjects. A one-way analysis of variance (ANOVA was performed to determine the regions in which the ReHo was different across the three groups. NMO-ON and ON subjects were distinguished from HCs by a receiver operating characteristic (ROC curve. The relationship between the mean ReHo in many brain regions and clinical features in NMO subjects was calculated by Pearson correlation analysis. Results: Compared with HCs, MOG-IgG+ON subjects had significantly decreased ReHo values in the posterior lobe of the left cerebellum and increased ReHo values in the left inferior frontal gyrus, right prefrontal gyrus, and left precentral/postcentral gyrus. AQP4-IgG+NMO-ON subjects showed higher ReHo values in the left inferior frontal gyrus and right middle temporal/occipital gyrus. Compared with MOG-IgG+ON subjects, AQP4-IgG+NMO-ON subjects had lower Re

Effects of acupuncture at GV20 and ST36 on the expression of matrix metalloproteinase 2, aquaporin 4, and aquaporin 9 in rats subjected to cerebral ischemia/reperfusion injury.

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Hong Xu

Full Text Available BACKGROUND/PURPOSE: Ischemic stroke is characterized by high morbidity and mortality worldwide. Matrix metalloproteinase 2 (MMP2, aquaporin (AQP 4, and AQP9 are linked to permeabilization of the blood-brain barrier (BBB in cerebral ischemia/reperfusion injury (CIRI. BBB disruption, tissue inflammation, and MMP/AQP upregulation jointly provoke brain edema/swelling after CIRI, while acupuncture and electroacupuncture can alleviate CIRI symptoms. This study evaluated the hypothesis that acupuncture and electroacupuncture can similarly exert neuroprotective actions in a rat model of middle cerebral artery occlusion (MCAO by modulating MMP2/AQP4/APQ9 expression and inflammatory cell infiltration. METHODS: Eighty 8-week-old Sprague-Dawley rats were randomly divided into sham group S, MCAO model group M, acupuncture group A, electroacupuncture group EA, and edaravone group ED. The MCAO model was established by placement of a suture to block the middle carotid artery, and reperfusion was triggered by suture removal in all groups except group S. Acupuncture and electroacupuncture were administered at acupoints GV20 (governing vessel-20 and ST36 (stomach-36. Rats in groups A, EA, and ED received acupuncture, electroacupuncture, or edaravone, respectively, immediately after MCAO. Neurological function (assessed using the Modified Neurological Severity Score, infarct volume, MMP2/AQP4/AQP9 mRNA and protein expression, and inflammatory cell infiltration were all evaluated at 24 h post-reperfusion. RESULTS: Acupuncture and electroacupuncture significantly decreased infarct size and improved neurological function. Furthermore, target mRNA and protein levels and inflammatory cell infiltration were significantly reduced in groups A, EA, and ED vs. group M. However, MMP2/AQP levels and inflammatory cell infiltration were generally higher in groups A and EA than in group ED except MMP2 mRNA levels. CONCLUSIONS: Acupuncture and electroacupuncture at GV20 and ST36

Neuromyelitis optica spectrum disorders: comparison of clinical and magnetic resonance imaging characteristics of AQP4-IgG versus MOG-IgG seropositive cases in the Netherlands.

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van Pelt, E D; Wong, Y Y M; Ketelslegers, I A; Hamann, D; Hintzen, R Q

2016-03-01

Neuromyelitis optica spectrum disorders (NMOSDs) are a group of rare inflammatory demyelinating disorders of the central nervous system. The identification of specific antibodies directed to aquaporin 4 (AQP4-IgG) led to the distinction from multiple sclerosis. However, up to 25% of the clinically diagnosed NMO patients are seronegative for AQP4-IgG. A subgroup of these patients might be identified by antibodies directed to myelin oligodendrocyte glycoprotein (MOG-IgG). Our objective was to investigate whether the clinical characteristics of these patients differ. Using a cell-based assay, samples of 61 AQP4-IgG seronegative patients and 41 AQP4-IgG seropositive patients with clinically NMOSD were analysed for the presence of MOG-IgG. Clinical characteristics of the AQP4-IgG, MOG-IgG seropositive and double seronegative NMOSD patients were compared. Twenty of the 61 AQP4-IgG seronegative patients tested MOG-IgG seropositive (33%). MOG-IgG seropositive patients were more frequently males in contrast to AQP4-IgG seropositive patients (55% vs. 15%, P < 0.01) and Caucasians (90% vs. 63%, P = 0.03). They more frequently presented with coincident optic neuritis and transverse myelitis (40% vs. 12%, P = 0.02) and had a monophasic disease course (70% vs. 29%, P < 0.01). AQP4-IgG seropositive patients were 2.4 times more likely to suffer from relapses compared with MOG-IgG seropositive patients (relative risk 2.4, 95% confidence interval 1.2-4.7). AQP4-IgG seropositive patients had higher Expanded Disability Status Scale levels at last follow-up (P < 0.01). Antibodies directed to MOG identify a subgroup of AQP4-IgG seronegative NMO patients with generally a favourable monophasic disease course. © 2015 EAN.

Expression of aquaporin 9 in rat liver and efferent ducts of the male reproductive system after neonatal diethylstilbestrol exposure

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Wellejus, Anja; Jensen, Henrik E; Loft, Steffen

2008-01-01

Aquaporins (AQP) have important solute transport functions in many tissues including the epididymal efferent ducts (ED) and in the liver. We investigated the effect of neonatal exposure to diethylstilbestrol (DES) on AQP9 expressions in the ED and in the liver of rats. DES was administered from d...... to the epithelial cells of the ED. In conclusion, neonatal DES exposure appears to upregulate AQP9 channels in the ED in male rats, whereas a downregulation in the hepatic expression was observed, particularly in the periacinous area....

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

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

2014-01-01

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

N-Acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191): an anti-inflammatory molecule that increases the expression of the aquaglyceroporin, aquaporin-3, in human keratinocytes.

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Fernández, José R; Webb, Corey; Rouzard, Karl; Voronkov, Michael; Huber, Kristen L; Stock, Jeffry B; Stock, Maxwell; Gordon, Joel S; Perez, Eduardo

2017-03-01

Isoprenylcysteine (IPC) small molecules were discovered as signal transduction modulating compounds ~25 years ago. More recently, IPC molecules have demonstrated antioxidant and anti-inflammatory properties in a variety of dermal cells as well as antimicrobial activity, representing a novel class of compounds to ameliorate skin conditions and disease. Here, we demonstrate a new IPC compound, N-acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191), which inhibits UVB-induced inflammation blocking pro-inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) production. To investigate further the previously reported hydrating potential of IPC compounds, SIG-1191 was tested for its ability to modulate aquaporin expression. Specifically, aquaporin 3 (AQP3) the most abundant aquaporin found in skin has been reported to play a key role in skin hydration, elasticity and barrier repair. Results show here for the first time that SIG-1191 increases AQP3 expression in both cultured normal human epidermal keratinocytes as well as when applied topically in a three-dimensional (3D) reconstructed human skin equivalent. Additionally, SIG-1191 dose dependently increased AQP3 protein levels, as determined by specific antibody staining, in the epidermis of the 3D skin equivalents. To begin to elucidate which signaling pathways SIG-1191 may be modulating to increase AQP3 levels, we used several pharmacological pathway inhibitors and determined that AQP3 expression is mediated by the Mitogen-activated protein kinase/Extracellular signal-regulated kinase kinase (MEK) pathway. Altogether, these data suggest SIG-1191 represents a new IPC derivative with anti-inflammatory activity that may also promote increased skin hydration based on its ability to increase AQP3 levels.

Oxygen-dependent regulation of aquaporin-3 expression

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Hoogewijs D

2016-04-01

Full Text Available David Hoogewijs,1,2 Melanie Vogler,3 Eveline Zwenger,3 Sabine Krull,3 Anke Zieseniss3 1Institute of Physiology, University of Duisburg-Essen, Essen, Germany; 2Institute of Physiology, University of Zürich, Zürich, Switzerland; 3Institute of Cardiovascular Physiology, University Medical Center Göttingen, University of Göttingen, Göttingen, GermanyAbstract: The purpose of this study was to investigate whether aquaporin-3 (AQP3 expression is altered in hypoxia and whether hypoxia-inducible transcription factor (HIF-1 regulates the hypoxic expression. AQP3 mRNA expression was studied in L929 fibrosarcoma cells and in several tissues derived from mice that were subjected to hypoxia. Computational analysis of the AQP3 promoter revealed conserved HIF binding sites within close proximity to the translational start site, and chromatin immunoprecipitation assays confirmed binding of HIF-1 to the endogenous hypoxia response elements. Furthermore, hypoxia resulted in increased expression of AQP3 mRNA in L929 fibrosarcoma cells. Consistently, shRNA-mediated knockdown of HIF-1 greatly reduced the hypoxic induction of AQP3. In addition, mRNA analysis of organs from mice exposed to inspiratory hypoxia demonstrated pronounced hypoxia-inducible expression of AQP3 in the kidney. Overall, our findings suggest that AQP3 expression can be regulated at the transcriptional level and that AQP3 represents a novel HIF-1 target gene. Keywords: transcriptional regulation, oxygen, hypoxia-inducible factor, hypoxia response element

NH3 and NH4+ permeability in aquaporin-expressing Xenopus oocytes

DEFF Research Database (Denmark)

Holm, Lars M.; Jahn, Thomas Paul; Møller, Anders Laurell Blom

2005-01-01

We have shown recently, in a yeast expression system, that some aquaporins are permeable to ammonia. In the present study, we expressed the mammalian aquaporins AQP8, AQQP9, AQP3, AQP1 and a plant aquaporin TIP2;1 in Xenopus oocytes to study the transport of ammonia (NH3) and ammonium (NH4+) under...... inwards currents carried by NH4+. This conductivity increased as a sigmoid function of external [NH3]: for AQP8 at a bath pH (pH(e)) of 6.5, the conductance was abolished, at pH(e) 7.4 it was half maximal and at pH(e) 7.8 it saturated. NY4+ influx was associated with oocyte swelling. In comparison, native...... oocytes as well as AQP1 and tip2;1-expressing oocytes showed small currents that were associated with small and even negative volume changes. We conclude that AQP8, AQP9, AQP3, and TIP2;1, apart from being water channels, also support significant fluxes of NH3. These aquaporins could support NH4...

Intrachromosomal amplification, locus deletion and point mutation in the aquaglyceroporin AQP1 gene in antimony resistant Leishmania (Viannia guyanensis.

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Rubens Monte-Neto

2015-02-01

Full Text Available Antimony resistance complicates the treatment of infections caused by the parasite Leishmania.Using next generation sequencing, we sequenced the genome of four independent Leishmania guyanensis antimony-resistant (SbR mutants and found different chromosomal alterations including aneuploidy, intrachromosomal gene amplification and gene deletion. A segment covering 30 genes on chromosome 19 was amplified intrachromosomally in three of the four mutants. The gene coding for the multidrug resistance associated protein A involved in antimony resistance was also amplified in the four mutants, most likely through chromosomal translocation. All mutants also displayed a reduced accumulation of antimony mainly due to genomic alterations at the level of the subtelomeric region of chromosome 31 harboring the gene coding for the aquaglyceroporin 1 (LgAQP1. Resistance involved the loss of LgAQP1 through subtelomeric deletions in three mutants. Interestingly, the fourth mutant harbored a single G133D point mutation in LgAQP1 whose role in resistance was functionality confirmed through drug sensitivity and antimony accumulation assays. In contrast to the Leishmania subspecies that resort to extrachromosomal amplification, the Viannia strains studied here used intrachromosomal amplification and locus deletion.This is the first report of a naturally occurred point mutation in AQP1 in antimony resistant parasites.

Chronic administration during early adulthood does not alter the hormonally-dependent disruptive effects of delta-9-tetrahydrocannabinol (Δ9-THC) on complex behavior in female rats.

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Winsauer, Peter J; Sutton, Jessie L

2014-02-01

This study examined whether chronic Δ(9)-THC during early adulthood would produce the same hormonally-dependent deficits in learning that are produced by chronic Δ(9)-THC during adolescence. To do this, either sham-operated (intact) or ovariectomized (OVX) female rats received daily saline or 5.6 mg/kg of Δ(9)-THC i.p. for 40 days during early adulthood. Following chronic administration, and a drug-free period to train both a learning and performance task, acute dose-effect curves for Δ(9)-THC (0.56-10 mg/kg) were established in each of the four groups (intact/saline, intact/THC, OVX/saline and OVX/THC). The dependent measures of responding under the learning and performance tasks were the overall response rate and the percentage of errors. Although the history of OVX and chronic Δ(9)-THC in early adulthood did not significantly affect non-drug or baseline behavior under the tasks, acute administration of Δ(9)-THC produced both rate-decreasing and error-increasing effects on learning and performance behavior, and these effects were dependent on their hormone condition. More specifically, both intact groups were more sensitive to the rate-decreasing and error-increasing effects of Δ(9)-THC than the OVX groups irrespective of chronic Δ(9)-THC administration, as there was no significant main effect of chronic treatment and no significant interaction between chronic treatment (saline or Δ(9)-THC) and the dose of Δ(9)-THC administered as an adult. Post mortem examination of 10 brain regions also indicated there were significant differences in agonist-stimulated GTPγS binding across brain regions, but no significant effects of chronic treatment and no significant interaction between the chronic treatment and cannabinoid signaling. Thus, acute Δ(9)-THC produced hormonally-dependent effects on learning and performance behavior, but a period of chronic administration during early adulthood did not alter these effects significantly, which is contrary to what we

[Mechanism of potassium channel in hypoxia-ischemic brain edema: experiment with neonatal rat astrocyte].

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Fu, Xue-mei; Xiang, Long; Liao, Da-qing; Feng, Zhi-chun; Mu, De-zhi

2008-11-04

To investigate the mechanism of potassium channel in brain edema caused by hypoxia-ischemia (HI). Astrocytes were obtained from 3-day-old SD rats, cultured, and randomly divided into 2 groups: normoxia group, cultured under normoxic condition, and hypoxic-ischemic group, cultured under hypoxic-ischemic condition. The cell volume was measured by radiologic method. Patch-clamp technique was used to observe the electric physiological properties of the voltage-gated potassium channels (Kv) in a whole cell configuration, and the change of voltage-gated potassium channel current (IKv) was recorded in cultured neonatal rat astrocyte during HI. Aquaporin 4 (AQP4) expression vector was constructed from pSUPER vector and transfected into the astrocytes (AQP4 RNAi) to construct AQP4 knockdown (AQP4-/-) cells. cellular volume was determined using [3H]-3-O-methyl-D-glucose uptake in both AQP4-/- and AQP4+/+ cells under the condition of HI. Real time PCR and Western blotting were used to detect the mRNA and protein expression of AQP4. The percentages of the AQP4+/+ and AQP4-/- astrocyte volumes in the condition of HI for 0.5, 1, 2, and 4 h were 104+/-7, 109+/-6, 126+/-12, and 152+/-9 times, and 97+/-7, 105+/-9, 109+/-7, and 132+/-6 times as those of their corresponding control groups (all Pastrocytes significantly increased during HI and the degrees of edema mediated by AQP4 knockdown at different time points were all significantly milder (all Pastrocytes via aquaporin-4 and then cell swelling.

Regional expression of aquaporins 1, 4, and 9 in the brain during pregnancy

NARCIS (Netherlands)

Wiegman, Marchien J.; Bullinger, Lisa V.; Kohlmeyer, Meghan M.; Hunter, Timothy C.; Cipolla, Marilyn J.

Pregnancy is a state of physiologic adaptation, with significant changes in cardiovascular, renal, and hemodynamic systems. Aquaporins (AQPs) may play a role in facilitating these changes. Mile AQP expression has been assessed in several organs during pregnancy, little is known about its expression

Phosphorylation of plasma membrane aquaporin regulates temperature-dependent opening of tulip petals.

Science.gov (United States)

Azad, Abul Kalam; Sawa, Yoshihiro; Ishikawa, Takahiro; Shibata, Hitoshi

2004-05-01

The opening and closing of tulip petals was reproduced in the dark by changing the temperature from 5 degrees C to 20 degrees C for opening and 20 degrees C to 5 degrees C for closing. The opening process was accompanied by (3)H(2)O transport through the stem from the incubation medium to the petals. A Ca(2+)-channel blocker and a Ca(2+)-chelator inhibited petal opening and (3)H(2)O transport. Several proteins in the isolated plasma membrane fraction were phosphorylated in the presence of 25 micro M Ca(2+) at 20 degrees C. The 31-kDa protein that was phosphorylated, was suggested immunologically as the putative plasma membrane aquaporin (PM-AQP). This phosphorylated PM-AQP clearly reacted with the anti-phospho-Ser. In-gel assay revealed the presence of a 45-kDa Ca(2+)-dependent protein kinase in the isolated plasma membrane. Phosphorylation of the putative PM-AQP was thought to activate the water channel composed of PM-AQP. Dephosphorylation of the phosphorylated PM-AQP was also observed during petal closing at 5 degrees C, suggesting the inactivation of the water channel.

Changes in Air CO2 Concentration Differentially Alter Transcript Levels of NtAQP1 and NtPIP2;1 Aquaporin Genes in Tobacco Leaves

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Francesca Secchi

2016-04-01

Full Text Available The aquaporin specific control on water versus carbon pathways in leaves is pivotal in controlling gas exchange and leaf hydraulics. We investigated whether Nicotiana tabacum aquaporin 1 (NtAQP1 and Nicotiana tabacum plasma membrane intrinsic protein 2;1 (NtPIP2;1 gene expression varies in tobacco leaves subjected to treatments with different CO2 concentrations (ranging from 0 to 800 ppm, inducing changes in photosynthesis, stomatal regulation and water evaporation from the leaf. Changes in air CO2 concentration ([CO2] affected net photosynthesis (Pn and leaf substomatal [CO2] (Ci. Pn was slightly negative at 0 ppm air CO2; it was one-third that of ambient controls at 200 ppm, and not different from controls at 800 ppm. Leaves fed with 800 ppm [CO2] showed one-third reduced stomatal conductance (gs and transpiration (E, and their gs was in turn slightly lower than in 200 ppm– and in 0 ppm–treated leaves. The 800 ppm air [CO2] strongly impaired both NtAQP1 and NtPIP2;1 gene expression, whereas 0 ppm air [CO2], a concentration below any in vivo possible conditions and specifically chosen to maximize the gene expression alteration, increased only the NtAQP1 transcript level. We propose that NtAQP1 expression, an aquaporin devoted to CO2 transport, positively responds to CO2 scarcity in the air in the whole range 0–800 ppm. On the contrary, expression of NtPIP2;1, an aquaporin not devoted to CO2 transport, is related to water balance in the leaf, and changes in parallel with gs. These observations fit in a model where upregulation of leaf aquaporins is activated at low Ci, while downregulation occurs when high Ci saturates photosynthesis and causes stomatal closure.

Systemic administration of lipopolysaccharide increases the expression of aquaporin-4 in the rat anterior pituitary gland.

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Kuwahara-Otani, Sachi; Maeda, Seishi; Tanaka, Koichi; Hayakawa, Tetsu; Seki, Makoto

2013-01-01

We investigated the effects of lipopolysaccharide (LPS)-induced endotoxemia on the expression of aquaporin-4 (AQP4) in the rat anterior pituitary gland, using the real-time polymerase chain reaction and immunohistochemistry. After intraperitoneal injection of LPS, the level of AQP4 mRNA doubled at 2, 4 and 8 hr. Immunohistochemical analysis showed an increase with time in AQP4 immunostaining in folliculo-stellate cells following LPS injection; the intensity of immunoreactivity peaked at 8 hr. At the same time, some cyst-like structures, formed by AQP4-positive cells, were observed. These findings indicate that LPS induces the expression of AQP4 in the anterior pituitary gland. The present results should provide an important key to elucidate the pathogenesis of the anterior pituitary gland during endotoxemia.

Induction stage-dependent expression of vascular endothelial growth factor and aquaporin-1 in diethylstilbestrol-treated rat pituitary

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W Zhao

2009-03-01

Full Text Available The anterior pituitary gland undergoes tumourigenic changes in response to oestrogen treatment in several breeds of rats. We administered diethylstilbestrol (DES to female Wistar rats and assessed whether the expression of vascular endothelial growth factor (VEGF and aquaporin-1 (AQP-1 was altered at different time points following DES administration. In vivo magnetic resonance imaging (MRI scans showed that the mass index corresponding to the mid-sagittal area of DES-treated pituitary was significantly higher than the vehicle-controlled pituitary (p less than 0.01 at three specific time points, accompanied by a significant reduction in body weight. Haematoxylin and eosin (HE staining and immunohistochemical analysis demonstrated that during early stages of induction, DES increased cell proliferation and sprouting of endothelial cells, and VEGF expression transitioned from a vessel-surrounding pattern to a diffuse pattern. During later stages, angiogenesis was predominant, and VEGF expression decreased. In contrast to the early abundant expression of VEGF, endothelial expression of AQP- 1 increased during later stages. Our data indicated a dynamic scenario of biological alterations in DES-treated pituitary tissue, in which VEGF and AQP-1 exert their functions at different stages of induction, and we provide novel insights into understanding oestrogen-related tumourigenesis in the anterior pituitary gland.

Induction stage-dependent expression of vascular endothelial growth factor and aquaporin-1 in diethylstilbestrol-treated rat pituitary

Directory of Open Access Journals (Sweden)

Z Wang

2009-03-01

Full Text Available The anterior pituitary gland undergoes tumourigenic changes in response to oestrogen treatment in several breeds of rats. We administered diethylstilbestrol (DES to female Wistar rats and assessed whether the expression of vascular endothelial growth factor (VEGF and aquaporin-1 (AQP-1 was altered at different time points following DES administration. In vivo magnetic resonance imaging (MRI scans showed that the mass index corresponding to the mid-sagittal area of DES-treated pituitary was significantly higher than the vehicle-controlled pituitary (p<0.01 at three specific time points, accompanied by a significant reduction in body weight. Haematoxylin and eosin (HE staining and immunohistochemical analysis demonstrated that during early stages of induction, DES increased cell proliferation and sprouting of endothelial cells, and VEGF expression transitioned from a vessel-surrounding pattern to a diffuse pattern. During later stages, angiogenesis was predominant, and VEGF expression decreased. In contrast to the early abundant expression of VEGF, endothelial expression of AQP- 1 increased during later stages. Our data indicated a dynamic scenario of biological alterations in DES-treated pituitary tissue, in which VEGF and AQP-1 exert their functions at different stages of induction, and we provide novel insights into understanding oestrogen-related tumourigenesis in the anterior pituitary gland.

Systems-level identification of PKA-dependent signaling in epithelial cells.

Science.gov (United States)

Isobe, Kiyoshi; Jung, Hyun Jun; Yang, Chin-Rang; Claxton, J'Neka; Sandoval, Pablo; Burg, Maurice B; Raghuram, Viswanathan; Knepper, Mark A

2017-10-17

G protein stimulatory α-subunit (G αs )-coupled heptahelical receptors regulate cell processes largely through activation of protein kinase A (PKA). To identify signaling processes downstream of PKA, we deleted both PKA catalytic subunits using CRISPR-Cas9, followed by a "multiomic" analysis in mouse kidney epithelial cells expressing the G αs -coupled V2 vasopressin receptor. RNA-seq (sequencing)-based transcriptomics and SILAC (stable isotope labeling of amino acids in cell culture)-based quantitative proteomics revealed a complete loss of expression of the water-channel gene Aqp2 in PKA knockout cells. SILAC-based quantitative phosphoproteomics identified 229 PKA phosphorylation sites. Most of these PKA targets are thus far unannotated in public databases. Surprisingly, 1,915 phosphorylation sites with the motif x-(S/T)-P showed increased phosphooccupancy, pointing to increased activity of one or more MAP kinases in PKA knockout cells. Indeed, phosphorylation changes associated with activation of ERK2 were seen in PKA knockout cells. The ERK2 site is downstream of a direct PKA site in the Rap1GAP, Sipa1l1, that indirectly inhibits Raf1. In addition, a direct PKA site that inhibits the MAP kinase kinase kinase Map3k5 (ASK1) is upstream of JNK1 activation. The datasets were integrated to identify a causal network describing PKA signaling that explains vasopressin-mediated regulation of membrane trafficking and gene transcription. The model predicts that, through PKA activation, vasopressin stimulates AQP2 exocytosis by inhibiting MAP kinase signaling. The model also predicts that, through PKA activation, vasopressin stimulates Aqp2 transcription through induction of nuclear translocation of the acetyltransferase EP300, which increases histone H3K27 acetylation of vasopressin-responsive genes (confirmed by ChIP-seq).

TRPV4 and AQP4 Channels Synergistically Regulate Cell Volume and Calcium Homeostasis in Retinal Müller Glia

DEFF Research Database (Denmark)

Jo, Andrew O; Ryskamp, Daniel A; Phuong, Tam T T

2015-01-01

Brain edema formation occurs after dysfunctional control of extracellular volume partly through impaired astrocytic ion and water transport. Here, we show that such processes might involve synergistic cooperation between the glial water channel aquaporin 4 (AQP4) and the transient receptor potent...

Expression patterns of the aquaporin gene family during renal development: influence of genetic variability.

Science.gov (United States)

Parreira, Kleber S; Debaix, Huguette; Cnops, Yvette; Geffers, Lars; Devuyst, Olivier

2009-08-01

High-throughput analyses have shown that aquaporins (AQPs) belong to a cluster of genes that are differentially expressed during kidney organogenesis. However, the spatiotemporal expression patterns of the AQP gene family during tubular maturation and the potential influence of genetic variation on these patterns and on water handling remain unknown. We investigated the expression patterns of all AQP isoforms in fetal (E13.5 to E18.5), postnatal (P1 to P28), and adult (9 weeks) kidneys of inbred (C57BL/6J) and outbred (CD-1) mice. Using quantitative polymerase chain reaction (PCR), we evidenced two mRNA patterns during tubular maturation in C57 mice. The AQPs 1-7-11 showed an early (from E14.5) and progressive increase to adult levels, similar to the mRNA pattern observed for proximal tubule markers (Megalin, NaPi-IIa, OAT1) and reflecting the continuous increase in renal cortical structures during development. By contrast, AQPs 2-3-4 showed a later (E15.5) and more abrupt increase, with transient postnatal overexpression. Most AQP genes were expressed earlier and/or stronger in maturing CD-1 kidneys. Furthermore, adult CD-1 kidneys expressed more AQP2 in the collecting ducts, which was reflected by a significant delay in excreting a water load. The expression patterns of proximal vs. distal AQPs and the earlier expression in the CD-1 strain were confirmed by immunoblotting and immunostaining. These data (1) substantiate the clustering of important genes during tubular maturation and (2) demonstrate that genetic variability influences the regulation of the AQP gene family during tubular maturation and water handling by the mature kidney.

Molecular characterization of branchial aquaporin 1aa and effects of seawater acclimation, emersion or ammonia exposure on its mRNA expression in the gills, gut, kidney and skin of the freshwater climbing perch, Anabas testudineus.

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Yuen K Ip

Full Text Available We obtained a full cDNA coding sequence of aquaporin 1aa (aqp1aa from the gills of the freshwater climbing perch, Anabas testudineus, which had the highest expression in the gills and skin, suggesting an important role of Aqp1aa in these organs. Since seawater acclimation had no significant effects on the branchial and intestinal aqp1aa mRNA expression, and since the mRNA expression of aqp1aa in the gut was extremely low, it can be deduced that Aqp1aa, despite being a water channel, did not play a significant osmoregulatory role in A. testudineus. However, terrestrial exposure led to significant increases in the mRNA expression of aqp1aa in the gills and skin of A. testudineus. Since terrestrial exposure would lead to evaporative water loss, these results further support the proposition that Aqp1aa did not function predominantly for the permeation of water through the gills and skin. Rather, increased aqp1aa mRNA expression might be necessary to facilitate increased ammonia excretion during emersion, because A. testudineus is known to utilize amino acids as energy sources for locomotor activity with increased ammonia production on land. Furthermore, ammonia exposure resulted in significant decreases in mRNA expression of aqp1aa in the gills and skin of A. testudineus, presumably to reduce ammonia influx during ammonia loading. This corroborates previous reports on AQP1 being able to facilitate ammonia permeation. However, a molecular characterization of Aqp1aa from A. testudineus revealed that its intrinsic aquapore might not facilitate NH3 transport. Hence, ammonia probably permeated the central fifth pore of the Aqp1aa tetramer as suggested previously. Taken together, our results indicate that Aqp1aa might have a greater physiological role in ammonia excretion than in osmoregulation in A. testudineus.

Silver and Nitrate Oppositely Modulate Antimony Susceptibility through Aquaglyceroporin 1 in Leishmania (Viannia) Species.

Science.gov (United States)

Andrade, Juvana M; Baba, Elio H; Machado-de-Avila, Ricardo A; Chavez-Olortegui, Carlos; Demicheli, Cynthia P; Frézard, Frédéric; Monte-Neto, Rubens L; Murta, Silvane M F

2016-08-01

Antimony (Sb) resistance in leishmaniasis chemotherapy has become one of the major challenges to the control of this spreading worldwide public health problem. Since the plasma membrane pore-forming protein aquaglyceroporin 1 (AQP1) is the major route of Sb uptake in Leishmania, functional studies are relevant to characterize drug transport pathways in the parasite. We generated AQP1-overexpressing Leishmania guyanensis and L. braziliensis mutants and investigated their susceptibility to the trivalent form of Sb (Sb(III)) in the presence of silver and nitrate salts. Both AQP1-overexpressing lines presented 3- to 4-fold increased AQP1 expression levels compared with those of their untransfected counterparts, leading to an increased Sb(III) susceptibility of about 2-fold. Competition assays using silver nitrate, silver sulfadiazine, or silver acetate prior to Sb(III) exposure increased parasite growth, especially in AQP1-overexpressing mutants. Surprisingly, Sb(III)-sodium nitrate or Sb(III)-potassium nitrate combinations showed significantly enhanced antileishmanial activities compared to those of Sb(III) alone, especially against AQP1-overexpressing mutants, suggesting a putative nitrate-dependent modulation of AQP1 activity. The intracellular level of antimony quantified by graphite furnace atomic absorption spectrometry showed that the concomitant exposure to Sb(III) and nitrate favors antimony accumulation in the parasite, increasing the toxicity of the drug and culminating with parasite death. This is the first report showing evidence of AQP1-mediated Sb(III) susceptibility modulation by silver in Leishmania and suggests the potential antileishmanial activity of the combination of nitrate salts and Sb(III). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Aquaporin expression in the fetal porcine urinary tract changes during gestation

DEFF Research Database (Denmark)

Jakobsen, L K; Trelborg, K; Kingo, P S

2018-01-01

The expression of aquaporins (AQPs) in the fetal porcine urinary tract and its relation to gestational age has not been established. Tissue samples from the renal pelvis, ureter, bladder and urethra were obtained from porcine fetuses. Samples were examined by RT-PCR (AQPs 1-11), QPCR (AQPs positive....... Immunohistochemistry showed AQP1 staining in sub-urothelial vessels at all locations. Western blotting analysis confirmed increased AQP1 protein levels in bladder samples during gestation. Expression levels of AQP1, 3, 5, 9 and 11 in the urinary tract change during gestation, and further studies are needed to provide...

The role of aquaporins in polycystic ovary syndrome - A way towards a novel drug target in PCOS.

Science.gov (United States)

Wawrzkiewicz-Jałowiecka, Agata; Kowalczyk, Karolina; Pluta, Dagmara; Blukacz, Łukasz; Madej, Paweł

2017-05-01

Aquaporins (AQPs) are transmembrane proteins, able to transport water (and in some cases also small solutes, e. g. glycerol) through the cell membrane. There are twelve types of aquaporins (AQP1-AQP12) expressed in mammalian reproductive systems. According to literature, many diseases of the reproductive organs are correlated with changes of AQPs expression and their malfunction. That is the case in the polycystic ovary syndrome (PCOS), where dysfunctions of AQPs 7-9 and alterations in its levels occur. In this work, we postulate how AQPs are involved in PCOS-related disorders, in order to emphasize their potential therapeutic meaning as a drug target. Our research allows for a surprising inference, that genetic mutation causing malfunction and/or decreased expression of aquaporins, may be incorporated in the popular insulin-dependent hypothesis of PCOS pathogenesis. What is more, changes in AQP's expression may affect the folliculogenesis and follicular atresia in PCOS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vasoactive Intestinal Peptide Protects Salivary Glands against Structural Injury and Secretory Dysfunction via IL-17A and AQP5 Regulation in a Model of Sjögren Syndrome.

Science.gov (United States)

Li, Chengyin; Zhu, Fenglin; Wu, Bin; Wang, Yue

2018-04-04

Sjögren syndrome (SS) is an autoimmune disease involving exocrine glands. Currently, drugs that can improve both abnormal immunity and exocrine gland function are needed. The study aimed to investigate the effect and mechanism of vasoactive intestinal peptide (VIP) on the immune response and exocrine gland function in SS. We investigated the effects of VIP on the immune response and secretory function of submandibular glands using NOD mice, and analyzed the expression of IL-17A and AQP5 (aquaporin 5). The submandibular gland cells from healthy 8-day-old Sprague-Dawley rats were used to observe the influence of VIP on AQP5 expression. Our study shows that treatment with VIP in an SS mouse model could not only reduce the immune injury to exocrine glands but also improve the secretory function of these glands. Furthermore, VIP was shown to improve the abnormal immune status by downregulating IL-17A expression in the exocrine glands. It also enhanced the secretory function of exocrine glands by upregulating AQP5 expression. Using a model of SS, we found that VIP could not only modulate the immune response but also affect exocrine gland function, and that these therapeutic effects were associated with IL-17A and AQP5 regulation. © 2018 S. Karger AG, Basel.

CHIP regulates aquaporin-2 quality control and body water homeostasis

DEFF Research Database (Denmark)

Wu, Qi; Moeller, Hanne B.; Stevens, Donté A.

2018-01-01

The importance of the kidney distal convoluted tubule (DCT) and cortical collecting duct (CCD) is highlighted by various water and electrolyte disorders that arise when the unique transport properties of these segments are disturbed. Despite this critical role, little is known about which proteins...... by vasopressin; interacts with aquaporin-2 (AQP2), Hsp70, and Hsc70; and can directly ubiquitylate the water channel AQP2 in vitro. shRNA knockdown of CHIP in CCD cells increased AQP2 protein t1/2 and reduced AQP2 ubiquitylation, resulting in greater levels of AQP2 andphosphorylatedAQP2.CHIP knockdown increased...... the plasma membrane abundance of AQP2 in these cells. Compared with wild-type controls, CHIP knockout mice or novel CRISPR/Cas9 mice without CHIPE3 ligase activity had greater AQP2 abundance and altered renal water handling, with decreased water intake and urine volume, alongside higher urine osmolality. We...

Topical Erythropoietin Treatment Accelerates the Healing of Cutaneous Burn Wounds in Diabetic Pigs Through an Aquaporin-3-Dependent Mechanism.

Science.gov (United States)

Hamed, Saher; Ullmann, Yehuda; Egozi, Dana; Keren, Aviad; Daod, Essam; Anis, Omer; Kabha, Hoda; Belokopytov, Mark; Ashkar, Manal; Shofti, Rona; Zaretsky, Asaph; Schlesinger, Michal; Teot, Luc; Liu, Paul Y

2017-08-01

We have previously reported that the topical application of erythropoietin (EPO) to cutaneous wounds in rats and mice with experimentally induced diabetes accelerates their healing by stimulating angiogenesis, reepithelialization, and collagen deposition, and by suppressing the inflammatory response and apoptosis. Aquaporins (AQPs) are integral membrane proteins whose function is to regulate intracellular fluid hemostasis by enabling the transport of water and glycerol. AQP3 is the AQP that is expressed in the skin where it facilitates cell migration and proliferation and re-epithelialization during wound healing. In this report, we provide the results of an investigation that examined the contribution of AQP3 to the mechanism of EPO action on the healing of burn wounds in the skin of pigs with experimentally induced type 1 diabetes. We found that topical EPO treatment of the burns accelerated their healing through an AQP3-dependent mechanism that activates angiogenesis, triggers collagen and hyaluronic acid synthesis and the formation of the extracellular matrix (ECM), and stimulates reepithelialization by keratinocytes. We also found that incorporating fibronectin, a crucial constituent of the ECM, into the topical EPO-containing gel, can potentiate the accelerating action of EPO on the healing of the burn injury. © 2017 by the American Diabetes Association.

Aquaporins in Digestive System.

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Zhu, Shuai; Ran, Jianhua; Yang, Baoxue; Mei, Zhechuan

2017-01-01

In this chapter, we mainly discuss the expression and function of aquaporins (AQPs ) expressed in digestive system . AQPs in gastrointestinal tract include four members of aquaporin subfamily: AQP1, AQP4, AQP5 and AQP8, and a member of aquaglyceroporin subfamily: AQP3. In the digestive glands, especially the liver, we discuss three members of aquaporin subfamily: AQP1, AQP5 and AQP8, a member of aquaglyceroporin subfamily: AQP9. AQP3 is involved in the diarrhea and inflammatory bowel disease; AQP5 is relevant to gastric carcinoma cell proliferation and migration; AQP9 plays considerable role in glycerol metabolism , urea transport and hepatocellular carcinoma. Further investigation is necessary for specific locations and functions of AQPs in digestive system.

Prognostic implication of aquaporin 1 overexpression in resected lung adenocarcinoma.

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Bellezza, Guido; Vannucci, Jacopo; Bianconi, Fortunato; Metro, Giulio; Del Sordo, Rachele; Andolfi, Marco; Ferri, Ivana; Siccu, Paola; Ludovini, Vienna; Puma, Francesco; Sidoni, Angelo; Cagini, Lucio

2017-12-01

Aquaporins (AQPs) are a group of transmembrane water-selective channel proteins thought to play a role in the regulation of water permeability for plasma membranes. Indeed, high AQP levels have been suggested to promote the progression, invasion and metastasis of tumours. Specifically, AQP1 and AQP5 overexpression in lung adenocarcinoma (AC) have been suggested to be involved in molecular mechanisms in lung cancer. The aim of this retrospective cohort single-centre study was to assess both the levels of expression and therein the prognostic significance, regarding outcome of AQP1 and AQP5 in resected AC patients. Patients with histological diagnoses of lung AC submitted to pulmonary resection were included in this cohort study. Tissue microarrays containing cores from 185 ACs were prepared. AQP1 and AQP5 expressions were assessed by immunohistochemistry. Results were scored as either low (Score 0-2) or high (Score 3-9). Clinical data, pathological tumour-node-metastasis staging and follow-up were recorded. Multivariate Cox survival analysis and Fisher's t-test were performed. AQP1 overexpression was detected in 85 (46%) patients, while AQP5 overexpression was observed in 45 (24%) patients. AQP1 did not result being significantly correlated with clinical and pathological parameters, while AQP5 resulted more expressed in AC with mucinous and papillary predominant patterns. Patients with AQP1 overexpression had shorter disease-free survival (P = 0.001) compared with patients without AQP1 overexpression. Multivariate analysis confirmed that AQP1 overexpression was significantly associated with shorter disease-free survival (P = 0.001). Our results evidenced that AQP1 overexpression resulted in a shorter disease-free survival in lung AC patients. Being so, AQP1 overexpression might be an important prognostic marker in lung AC. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) produces edema due to BBB disruption induced by MMP-9 activation in rat hippocampus.

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Pérez-Hernández, Mercedes; Fernández-Valle, María Encarnación; Rubio-Araiz, Ana; Vidal, Rebeca; Gutiérrez-López, María Dolores; O'Shea, Esther; Colado, María Isabel

2017-05-15

The recreational drug of abuse, 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) disrupts blood-brain barrier (BBB) integrity in rats through an early P2X 7 receptor-mediated event which induces MMP-9 activity. Increased BBB permeability often causes plasma proteins and water to access cerebral tissue leading to vasogenic edema formation. The current study was performed to examine the effect of a single neurotoxic dose of MDMA (12.5 mg/kg, i.p.) on in vivo edema development associated with changes in the expression of the perivascular astrocytic water channel, AQP4, as well as in the expression of the tight-junction (TJ) protein, claudin-5 and Evans Blue dye extravasation in the hippocampus of adult male Dark Agouti rats. We also evaluated the ability of the MMP-9 inhibitor, SB-3CT (25 mg/kg, i.p.), to prevent these changes in order to validate the involvement of MMP-9 activation in MDMA-induced BBB disruption. The results show that MDMA produces edema of short duration temporally associated with changes in AQP4 expression and a reduction in claudin-5 expression, changes which are prevented by SB-3CT. In addition, MDMA induces a short-term increase in both tPA activity and expression, a serine-protease which is involved in BBB disruption and upregulation of MMP-9 expression. In conclusion, this study provides evidence enough to conclude that MDMA induces edema of short duration due to BBB disruption mediated by MMP-9 activation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

Institute of Scientific and Technical Information of China (English)

HuaHu; Wei-PingZhang; LeiZhang; ZhongChen; Er-QingWei

2004-01-01

Aquaporin-4 (AQP4) is one of the aquaporins (AQPs), a water channel family. In the brain, AQP4 is expressed in astroeyte foot processes, and plays an important role in water homeostasis and in the formation of brain edema. In our study, AQP4 expression in human brain specimens from patients with traumatic brain injury or different brain tumors was detected

Physical dependence increases the relative reinforcing effects of caffeine versus placebo.

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Garrett, B E; Griffiths, R R

1998-10-01

Using a within-subject cross-over design, this study examined the role of physical dependence in caffeine reinforcement by experimentally manipulating physical dependence. Each subject was exposed to two chronic drug phases (300 mg/70 kg/day caffeine and placebo) for 9-12 days, with order of phases counterbalanced across subjects. On 2 separate days immediately following each of the chronic drug exposures, subjects received acute doses of either caffeine (300 mg/70 kg) or placebo in counterbalanced order. The reinforcing effects of these drugs were then determined by using a multiple-choice procedure in which subjects made a series of discrete choices between receiving varying amounts of money or receiving the drug again, and a choice between the two drugs. To ensure that subjects completed the form carefully, following exposure to both of the acute drug administrations, one of the subject's previous choices from the multiple-choice form was randomly selected and the consequence of that choice was implemented. When subjects were maintained on chronic caffeine, they were willing to forfeit significantly more money and showed significant increases in typical withdrawal symptoms (e.g. fatigue, mood disturbance) after receiving placebo as compared to the other three conditions. When subjects were maintained on chronic caffeine, they also chose to receive caffeine over placebo twice as often than when they were maintained on chronic placebo. These findings provide the strongest evidence to date indicating that caffeine physical dependence increases the relative reinforcing effects of caffeine versus placebo.

Overexpression of Aquaporin-1 and Caveolin-1 in the Rat Urinary Bladder Urothelium Following Bladder Outlet Obstruction

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Sun-Ouck Kim

2013-12-01

Full Text Available Purpose This study was designed to investigate the effect of detrusor overactivity induced by partial bladder outlet obstruction (BOO on the expression of aquaporin 1 (AQP1 and caveolin 1 (CAV1 in the rat urinary bladder, and to determine the role of these molecules in detrusor overactivity. Methods Female Sprague-Dawley rats were divided into control (n=30 and experimental (n=30 groups. The BOO group underwent partial BOO, and the control group underwent a sham operation. After 4 weeks, an urodynamic study was performed to measure the contraction interval and contraction pressure. The expression and cellular localization of AQP1 and CAV1 were determined by western blot and immunofluorescence experiments in the rat urinary bladder. Results In cystometrograms, the contraction interval was significantly lower in the BOO group (2.9±1.5 minutes than in the control group (6.7±1.0 minutes (P<0.05. Conversely, the average contraction pressure was significantly higher in the BOO group (21.2±3.3 mmHg than in the control group (13.0±2.5 mmHg (P<0.05. AQP1 and CAV1 were coexpressed in the capillaries, arterioles, and venules of the suburothelial layer. AQP1 and CAV1 protein expression was significantly increased in the BOO rats compared to the control rats (P<0.05. Conclusions Detrusor overactivity induced by BOO causes a significant increase in the expression of AQP1 and CAV1, which were coexpressed in the suburothelial microvasculature. This finding suggests that AQP1 and CAV1 might be closely related to bladder signal activity and may have a functional role in BOO-associated detrusor overactivity.

Expression profiles of aquaporins in rat conjunctiva, cornea, lacrimal gland and Meibomian gland.

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Yu, Dongfang; Thelin, William R; Randell, Scott H; Boucher, Richard C

2012-10-01

The aim of the study was to elucidate aquaporin (AQP) family member mRNA expression and protein expression/localization in the rat lacrimal functional unit. The mRNA expression of all rat AQPs (AQP0-9, 11-12) in palpebral, fornical, and bulbar conjunctiva, cornea, lacrimal gland, and Meibomian gland was measured by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and real time RT-PCR. Antibodies against AQP1, 3, 4, 5, 9, and 11 were used in Western blotting and immunohistochemistry to determine protein expression and distribution. Our study demonstrated characteristic AQP expression profiles in rat ocular tissues. AQP1, 3, 4, 5, 8, 9, 11, and 12 mRNA were detected in conjunctiva. AQP0, 1, 2, 3, 4, 5, 6, 11, and 12 mRNA were expressed in cornea. AQP0, 1, 2, 3, 4, 5, 7, 8, and 11 mRNA were detected in lacrimal gland. AQP1, 3, 4, 5, 7, 8, 9, 11, and 12 mRNA were identified in Meibomian gland. By Western blot, AQP1, 3, 5, and 11 were detected in conjunctiva; AQP1, 3, 5, and 11 were identified in cornea; AQP1, 3, 4, 5, and 11 were detected in lacrimal gland; and AQP1, 3, 4, 5, 9, and 11 were present in Meibomian gland. Immunohistochemistry localized AQPs to distinct sites in the various tissues. This study rigorously analyzed AQPs expression and localization in rat conjunctiva, cornea, lacrimal gland, and Meibomian gland tissues. Our findings provide a comprehensive platform for further investigation into the physiological or pathophysiological relevance of AQPs in ocular surface. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pharmacological blockade of aquaporin-1 water channel by AqB013 restricts migration and invasiveness of colon cancer cells and prevents endothelial tube formation in vitro.

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Dorward, Hilary S; Du, Alice; Bruhn, Maressa A; Wrin, Joseph; Pei, Jinxin V; Evdokiou, Andreas; Price, Timothy J; Yool, Andrea J; Hardingham, Jennifer E

2016-02-24

Aquaporins (AQP) are water channel proteins that enable fluid fluxes across cell membranes, important for homeostasis of the tissue environment and for cell migration. AQP1 knockout mouse models of human cancers showed marked inhibition of tumor-induced angiogenesis, and in pre-clinical studies of colon adenocarcinomas, forced over-expression of AQP1 was shown to increase angiogenesis, invasion and metastasis. We have synthesized small molecule antagonists of AQP1. Our hypothesis is that inhibition of AQP1 will reduce migration and invasiveness of colon cancer cells, and the migration and tube-forming capacity of endothelial cells in vitro. Expression of AQP1 in cell lines was assessed by quantitative (q) PCR, western blot and immunofluorescence, while expression of AQP1 in human colon tumour tissue was assessed by immunohistochemistry. The effect of varying concentrations of the AQP1 inhibitor AqB013 was tested on human colon cancer cell lines expressing high versus low levels of AQP1, using wound closure (migration) assays, matrigel invasion assays, and proliferation assays. The effect of AqB013 on angiogenesis was tested using an endothelial cell tube-formation assay. HT29 colon cancer cells with high AQP1 levels showed significant inhibition of migration compared to vehicle control of 27.9% ± 2.6% (p migration of HCT-116 cells with low AQP1 expression. In an invasion assay, HT29 cells treated with 160 μM of AqB013, showed a 60.3% ± 8.5% decrease in invasion at 144 hours (p < 0.0001) and significantly decreased rate of invasion compared with the vehicle control (F-test, p = 0.001). Almost complete inhibition of endothelial tube formation (angiogenesis assay) was achieved at 80 μM AqB013 compared to vehicle control (p < 0.0001). These data provide good evidence for further testing of the inhibitor as a therapeutic agent in colon cancer.

Altered aquaporin expression in glaucoma eyes

DEFF Research Database (Denmark)

Tran, Thuy Linh; Bek, Toke; Cour, Morten la

2014-01-01

Aquaporins (AQP) are channels in the cell membrane that mainly facilitate a passive transport of water. In the eye, AQPs are expressed in the ciliary body and retina and may contribute to the pathogenesis of glaucoma and optic neuropathy. We investigated the expression of AQP1, AQP3, AQP4, AQP5......, AQP7 and AQP9 in human glaucoma eyes compared with normal eyes. Nine glaucoma eyes were examined. Of these, three eyes were diagnosed with primary open angle glaucoma; three eyes had neovascular glaucoma; and three eyes had chronic angle-closure glaucoma. Six eyes with normal intraocular pressure...... and without glaucoma were used as control. Immunohistochemistry was performed using antibodies against AQP1, AQP3, AQP4, AQP5, AQP7 and AQP9. For each specimen, optical densities of immunoprecipitates were measured using Photoshop and the staining intensities were calculated. Immunostaining showed labelling...

Increased renal sodium absorption by inhibition of prostaglandin synthesis during fasting in healthy man. A possible role of the epithelial sodium channels

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Graffe Carolina C

2010-10-01

Full Text Available Abstract Background Treatment with prostaglandin inhibitors can reduce renal function and impair renal water and sodium excretion. We tested the hypotheses that a reduction in prostaglandin synthesis by ibuprofen treatment during fasting decreased renal water and sodium excretion by increased absorption of water and sodium via the aquaporin2 water channels and the epithelial sodium channels. Methods The effect of ibuprofen, 600 mg thrice daily, was measured during fasting in a randomized, placebo-controlled, double-blinded crossover study of 17 healthy humans. The subjects received a standardized diet on day 1, fasted at day 2, and received an IV infusion of 3% NaCl on day 3. The effect variables were urinary excretions of aquaporin2 (u-AQP2, the beta-fraction of the epithelial sodium channel (u-ENaCbeta, cyclic-AMP (u-cAMP, prostaglandin E2 (u-PGE2. Free water clearance (CH2O, fractional excretion of sodium (FENa, and plasma concentrations of vasopressin, angiotensin II, aldosterone, atrial-, and brain natriuretic peptide. Results Ibuprofen decreased u-AQP2, u-PGE2, and FENa at all parts of the study. During the same time, ibuprofen significantly increased u-ENaCbeta. Ibuprofen did not change the response in p-AVP, u-c-AMP, urinary output, and free water clearance during any of these periods. Atrial-and brain natriuretic peptide were higher. Conclusion During inhibition of prostaglandin synthesis, urinary sodium excretion decreased in parallel with an increase in sodium absorption and increase in u-ENaCbeta. U-AQP2 decreased indicating that water transport via AQP2 fell. The vasopressin-c-AMP-axis did not mediate this effect, but it may be a consequence of the changes in the natriuretic peptide system and/or the angiotensin-aldosterone system Trial Registration Clinical Trials Identifier: NCT00281762

Rat Aquaporin-5 Is pH-Gated Induced by Phosphorylation and Is Implicated in Oxidative Stress

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Claudia Rodrigues

2016-12-01

Full Text Available Aquaporin-5 (AQP5 is a membrane water channel widely distributed in human tissues that was found up-regulated in different tumors and considered implicated in carcinogenesis in different organs and systems. Despite its wide distribution pattern and physiological importance, AQP5 short-term regulation was not reported and mechanisms underlying its involvement in cancer are not well defined. In this work, we expressed rat AQP5 in yeast and investigated mechanisms of gating, as well as AQP5’s ability to facilitate H2O2 plasma membrane diffusion. We found that AQP5 can be gated by extracellular pH in a phosphorylation-dependent manner, with higher activity at physiological pH 7.4. Moreover, similar to other mammalian AQPs, AQP5 is able to increase extracellular H2O2 influx and to affect oxidative cell response with dual effects: whereas in acute oxidative stress conditions AQP5 induces an initial higher sensitivity, in chronic stress AQP5 expressing cells show improved cell survival and resistance. Our findings support the involvement of AQP5 in oxidative stress and suggest AQP5 modulation by phosphorylation as a novel tool for therapeutics.

Protection of Vascular Endothelial Growth Factor to Brain Edema Following Intracerebral Hemorrhage and Its Involved Mechanisms: Effect of Aquaporin-4.

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Heling Chu

Full Text Available Vascular endothelial growth factor (VEGF has protective effects on many neurological diseases. However, whether VEGF acts on brain edema following intracerebral hemorrhage (ICH is largely unknown. Our previous study has shown aquaporin-4 (AQP4 plays an important role in brain edema elimination following ICH. Meanwhile, there is close relationship between VEGF and AQP4. In this study, we aimed to test effects of VEGF on brain edema following ICH and examine whether they were AQP4 dependent. Recombinant human VEGF165 (rhVEGF165 was injected intracerebroventricularly 1 d after ICH induced by microinjecting autologous whole blood into striatum. We detected perihemotomal AQP4 protein expression, then examined the effects of rhVEGF165 on perihemotomal brain edema at 1 d, 3 d, and 7 d after injection in wild type (AQP4(+/+ and AQP4 knock-out (AQP4(-/- mice. Furthermore, we assessed the possible signal transduction pathways activated by VEGF to regulate AQP4 expression via astrocyte cultures. We found perihemotomal AQP4 protein expression was highly increased by rhVEGF165. RhVEGF165 alleviated perihemotomal brain edema in AQP4(+/+ mice at each time point, but had no effect on AQP4(-/- mice. Perihemotomal EB extravasation was increased by rhVEGF165 in AQP4(-/- mice, but not AQP4(+/+ mice. RhVEGF165 reduced neurological deficits and increased Nissl's staining cells surrounding hemotoma in both types of mice and these effects were related to AQP4. RhVEGF165 up-regulated phospharylation of C-Jun amino-terminal kinase (p-JNK and extracellular signal-regulated kinase (p-ERK and AQP4 protein in cultured astrocytes. The latter was inhibited by JNK and ERK inhibitors. In conclusion, VEGF reduces neurological deficits, brain edema, and neuronal death surrounding hemotoma but has no influence on BBB permeability. These effects are closely related to AQP4 up-regulation, possibly through activating JNK and ERK pathways. The current study may present new insights to

Arsenic transport by zebrafish aquaglyceroporins

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Landfear Scott M

2009-11-01

Full Text Available Abstract Background Arsenic is one of the most ubiquitous toxins and endangers the health of tens of millions of humans worldwide. It is a mainly a water-borne contaminant. Inorganic trivalent arsenic (AsIII is one of the major species that exists environmentally. The transport of AsIII has been studied in microbes, plants and mammals. Members of the aquaglyceroporin family have been shown to actively conduct AsIII and its organic metabolite, monomethylarsenite (MAsIII. However, the transport of AsIII and MAsIII in in any fish species has not been characterized. Results In this study, five members of the aquaglyceroporin family from zebrafish (Danio rerio were cloned, and their ability to transport water, glycerol, and trivalent arsenicals (AsIII and MAsIII and antimonite (SbIII was investigated. Genes for at least seven aquaglyceroporins have been annotated in the zebrafish genome project. Here, five genes which are close homologues to human AQP3, AQP9 and AQP10 were cloned from a zebrafish cDNA preparation. These genes were named aqp3, aqp3l, aqp9a, aqp9b and aqp10 according to their similarities to the corresponding human AQPs. Expression of aqp9a, aqp9b, aqp3, aqp3l and aqp10 in multiple zebrafish organs were examined by RT-PCR. Our results demonstrated that these aquaglyceroporins exhibited different tissue expression. They are all detected in more than one tissue. The ability of these five aquaglyceroporins to transport water, glycerol and the metalloids arsenic and antimony was examined following expression in oocytes from Xenopus leavis. Each of these channels showed substantial glycerol transport at equivalent rates. These aquaglyceroporins also facilitate uptake of inorganic AsIII, MAsIII and SbIII. Arsenic accumulation in fish larvae and in different tissues from adult zebrafish was studied following short-term arsenic exposure. The results showed that liver is the major organ of arsenic accumulation; other tissues such as gill, eye

Plasma PCSK9 levels are significantly modified by statins and fibrates in humans

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Mbikay Majambu

2008-06-01

Full Text Available Abstract Background Proprotein convertase subtilisin kexin-like 9 (PCSK9 is a secreted glycoprotein that is transcriptionally regulated by cholesterol status. It modulates levels of circulating low density lipoprotein cholesterol (LDLC by negatively regulating low density lipoprotein receptor (LDLR levels. PCSK9 variants that result in 'gain of function' have been linked to autosomal dominant hypercholesterolemia, while significant protection from coronary artery disease has been documented in individuals who carry 'loss of function' PCSK9 variants. PCSK9 circulates in human plasma, and we previously reported that plasma PCSK9 is positively correlated with total cholesterol and LDLC in men. Results Herein, we report the effects of two lipid-modulating therapies, namely statins and fibrates, on PCSK9 plasma levels in human subjects. We also document their effects on endogenous PCSK9 and LDLR expression in a human hepatocyte cell line, HepG2, using immunoprecipitation and immunoblot analyses. Changes in plasma PCSK9 following fenofibrate or gemfibrozil treatments (fibric acid derivatives were inversely correlated with changes in LDLC levels (r = -0.558, p = 0.013. Atorvastatin administration (HMGCoA reductase inhibitor significantly increased plasma PCSK9 (7.40%, p = 0.033 and these changes were inversely correlated with changes in LDLC levels (r = -0.393, p = 0.012. Immunoblot analyses of endogenous PCSK9 and LDLR expression by HepG2 cells in response to statins and fibrates showed that LDLR is more upregulated than PCSK9 by simvastatin (2.6× vs 1.5×, respectively at 10 μM, while fenofibrate did not induce changes in either. Conclusion These results suggest that in vivo (1 statins directly increase PCSK9 expression while (2 fibrates affect PCSK9 expression indirectly through its modulation of cholesterol levels and (3 that these therapies could be improved by combination with a PCSK9 inhibitor, constituting a novel hypercholesterolemic therapy

Relationship between aquaporin-5 expression and saliva flow in streptozotocin-induced diabetic mice?

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Soyfoo, M S; Bolaky, N; Depoortere, I; Delporte, C

2012-07-01

To investigate the expression and distribution of AQP5 in submandibular acinar cells from sham- and streptozotocin (STZ)-treated mice in relation to the salivary flow. Mice were sham or STZ injected. Distribution of AQP5 subcellular expression in submandibular glands was determined by immunohistochemistry. AQP5 labelling indices (LI), reflecting AQP5 subcellular distribution, were determined in acinar cells. Western blotting was performed to determine the expression of AQP5 in submandibular glands. Blood glycaemia and osmolality and saliva flow rates were also determined. AQP5 immunoreactivity was primarily located at the apical and apical-basolateral membranes of submandibular gland acinar cells from sham- and STZ-treated mice. No significant differences in AQP5 protein levels were observed between sham- and STZ-treated mice. Compared to sham-treated mice, STZ-treated mice had significant increased glycaemia, while no significant differences in blood osmolality were observed. Saliva flow rate was significantly decreased in STZ-treated mice as compared to sham-treated mice. In STZ-treated mice, significant reduction in salivary flow rate was observed without any concomitant modification in AQP5 expression and localization. © 2011 John Wiley & Sons A/S.

Opposing effects of cAMP and T259 phosphorylation on plasma membrane diffusion of the water channel aquaporin-5 in Madin-Darby canine kidney cells

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Koffman, Jennifer Skaarup; Christensen, Eva Arnspang; Marlar, Saw

2015-01-01

Aquaporin-5 (AQP5) facilitates passive water transport in glandular epithelia in response to secretory stimuli via intracellular pathways involving calcium release, cAMP and protein kinase A (PKA). In epithelial plasma membranes, AQP5 may be acutely regulated to facilitate water transport...... in the plasma membrane diffusion coefficient of AQP5. We aimed to test the short-term regulatory effects of the above pathways, by measuring lateral diffusion of AQP5 and an AQP5 phospho-mutant, T259A, using k-space Image Correlation Spectroscopy of quantum dot- and EGFP-labeled AQP5. Elevated cAMP and PKA...... inhibition significantly decreased lateral diffusion of AQP5, whereas T259A mutation showed opposing effects; slowing diffusion without stimulation and increasing diffusion to basal levels after cAMP elevation. Thus, lateral diffusion of AQP5 is significantly regulated by cAMP, PKA, and T259 phosphorylation...

G9a stimulates CRC growth by inducing p53 Lys373 dimethylation-dependent activation of Plk1.

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Zhang, Jie; Wang, Yafang; Shen, Yanyan; He, Pengxing; Ding, Jian; Chen, Yi

2018-01-01

Rationale: G9a is genetically deregulated in various tumor types and is important for cell proliferation; however, the mechanism underlying G9a-induced carcinogenesis, especially in colorectal cancer (CRC), is unclear. Here, we investigated if G9a exerts oncogenic effects in CRC by increasing polo-like kinase 1 (Plk1) expression. Thus, we further characterized the detailed molecular mechanisms. Methods: The role of Plk1 in G9a aberrant CRC was determined by performing different in vitro and in vivo assays, including assessment of cell growth by performing cell viability assay and assessment of signaling transduction profiles by performing immunoblotting, in the cases of pharmacological inhibition or short RNA interference-mediated suppression of G9a. Detailed molecular mechanisms underlying the effect of G9a on Plk1 expression were determined by performing point mutation analysis, chromatin immunoprecipitation analysis, and luciferase reporter assay. Correlation between G9a and Plk1 expression was determined by analyzing clinical samples of patients with CRC by performing immunohistochemistry. Results: Our study is the first to report a significant positive correlation between G9a and Plk1 levels in 89 clinical samples of patients with CRC. Moreover, G9a depletion decreased Plk1 expression and suppressed CRC cell growth both in vitro and in vivo , thus confirming the significant correlation between G9a and Plk1 levels. Further, we observed that G9a-induced Plk1 regulation depended on p53 inhibition. G9a dimethylated p53 at lysine 373, which in turn increased Plk1 expression and promoted CRC cell growth. Conclusions: These results indicate that G9a-induced and p53-dependent epigenetic programing stimulates the growth of colon cancer, which also suggests that G9a inhibitors that restore p53 activity are promising therapeutic agents for treating colon cancer, especially for CRC expressing wild-type p53.

Renal aquaporins and water balance disorders

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Kortenoeven, Marleen; Fenton, Robert A.

2013-01-01

BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, A......-solute diet and diuretics. GENERAL SIGNIFICANCE: In recent years, our understanding of the underlying mechanisms of water balance disorders has increased enormously, which has opened up several possible new treatment strategies.......BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP......2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW: This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS: Dysfunctions of AQPs are involved in disorders...

[Effects of aquaporin-4 gene knockout on behavior changes and cerebral morphology during aging in mice].

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Su, Shengan; Lu, Yunbi; Zhang, Weiping

2013-05-01

To investigate the effects of aquaporin-4 (AQP4) gene knockout on the behavior changes and cerebral morphology during aging in mice,and to compare that of young and aged mice between AQP4 knockout mice (AQP4(-/-)) and wild type mice (AQP4(+/+)). Fifty-eight CD-1 mice were divided into four groups: young (2-3 months old) AQP4(-/-), aged (17-19 months old) AQP4(-/-), young AQP4(+/+) and aged AQP4(+/+). The activity levels and exploring behavior of mice were tested in open field. The neurons were stained with toluidine blue and NeuN, the astrocytes and microglia were stained with GFAP and Iba-1, respectively. The morphological changes of neuron, astrocyte and microglia were then analyzed. Compared with young mice, the total walking distance in open field of aged AQP4(+/+) mice and aged AQP4(-/-) mice decreased 41.2% and 44.1%, respectively (Ptime in the central area of open field. The density of neuron in cortex of aged AQP4(+/+) mice and aged AQP4(-/-) mice decreased 19.6% and 15.8%, respectively (P<0.05), while there was no difference in the thickness of neuron cell body in hippocampus CA1 region. The density of astrocyte in hippocampus CA3 region of aged AQP4(+/+) mice and aged AQP4(-/-) mice increased 57.7% and 64.3%, respectively (P<0.001), while there was no difference in the area of astrocyte. The area of microglia in hippocampus CA3 region of aged AQP4(+/+) mice and aged AQP4(-/-) mice increased 46.9% and 52.0%, respectively (P<0.01), while there was no difference in the density of microglia. Compared with AQP4(+/+) mice, the young and aged AQP4(-/-) mice showed smaller area of astrocyte in hippocampus CA3 region, reduced 18.0% in young mice and 23.6% in aged mice. There was no difference between AQP4(+/+) mice and AQP4(-/-) mice for other observed indexes. AQP4 may be involved in change of astrocyte and astrocyte-related behaviors during aging. AQP4 gene knockout may have limited effects on the change of neuron, microglia and most neuronal behaviors in aging

Relationship between Hexokinase and the Aquaporin PIP1 in the Regulation of Photosynthesis and Plant Growth

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Kelly, Gilor; Sade, Nir; Attia, Ziv; Secchi, Francesca; Zwieniecki, Maciej; Holbrook, N. Michele; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Granot, David

2014-01-01

Increased expression of the aquaporin NtAQP1, which is known to function as a plasmalemma channel for CO2 and water, increases the rate of both photosynthesis and transpiration. In contrast, increased expression of Arabidopsis hexokinase1 (AtHXK1), a dual-function enzyme that mediates sugar sensing, decreases the expression of photosynthetic genes and the rate of transpiration and inhibits growth. Here, we show that AtHXK1 also decreases root and stem hydraulic conductivity and leaf mesophyll CO2 conductance (g m). Due to their opposite effects on plant development and physiology, we examined the relationship between NtAQP1 and AtHXK1 at the whole-plant level using transgenic tomato plants expressing both genes simultaneously. NtAQP1 significantly improved growth and increased the transpiration rates of AtHXK1-expressing plants. Reciprocal grafting experiments indicated that this complementation occurs when both genes are expressed simultaneously in the shoot. Yet, NtAQP1 had only a marginal effect on the hydraulic conductivity of the double-transgenic plants, suggesting that the complementary effect of NtAQP1 is unrelated to shoot water transport. Rather, NtAQP1 significantly increased leaf mesophyll CO2 conductance and enhanced the rate of photosynthesis, suggesting that NtAQP1 facilitated the growth of the double-transgenic plants by enhancing mesophyll conductance of CO2. PMID:24498392

Relationship between hexokinase and the aquaporin PIP1 in the regulation of photosynthesis and plant growth.

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Gilor Kelly

Full Text Available Increased expression of the aquaporin NtAQP1, which is known to function as a plasmalemma channel for CO₂ and water, increases the rate of both photosynthesis and transpiration. In contrast, increased expression of Arabidopsis hexokinase1 (AtHXK1, a dual-function enzyme that mediates sugar sensing, decreases the expression of photosynthetic genes and the rate of transpiration and inhibits growth. Here, we show that AtHXK1 also decreases root and stem hydraulic conductivity and leaf mesophyll CO₂ conductance (g(m. Due to their opposite effects on plant development and physiology, we examined the relationship between NtAQP1 and AtHXK1 at the whole-plant level using transgenic tomato plants expressing both genes simultaneously. NtAQP1 significantly improved growth and increased the transpiration rates of AtHXK1-expressing plants. Reciprocal grafting experiments indicated that this complementation occurs when both genes are expressed simultaneously in the shoot. Yet, NtAQP1 had only a marginal effect on the hydraulic conductivity of the double-transgenic plants, suggesting that the complementary effect of NtAQP1 is unrelated to shoot water transport. Rather, NtAQP1 significantly increased leaf mesophyll CO₂ conductance and enhanced the rate of photosynthesis, suggesting that NtAQP1 facilitated the growth of the double-transgenic plants by enhancing mesophyll conductance of CO₂.

The Role of Aquaporins in pH-Dependent Germination of Rhizopus delemar Spores.

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Tidhar Turgeman

Full Text Available Rhizopus delemar and associated species attack a wide range of fruit and vegetables after harvest. Host nutrients and acidic pH are required for optimal germination of R. delemar, and we studied how this process is triggered. Glucose induced spore swelling in an acidic environment, expressed by an up to 3-fold increase in spore diameter, whereas spore diameter was smaller in a neutral environment. When suspended in an acidic environment, the spores started to float, indicating a change in their density. Treatment of the spores with HgCl2, an aquaporin blocker, prevented floating and inhibited spore swelling and germ-tube emergence, indicating the importance of water uptake at the early stages of germination. Two putative candidate aquaporin-encoding genes-RdAQP1 and RdAQP2-were identified in the R. delemar genome. Both presented the conserved NPA motif and six-transmembrane domain topology. Expressing RdAQP1 and RdAQP2 in Arabidopsis protoplasts increased the cells' osmotic water permeability coefficient (Pf compared to controls, indicating their role as water channels. A decrease in R. delemar aquaporin activity with increasing external pH suggested pH regulation of these proteins. Substitution of two histidine (His residues, positioned on two loops facing the outer side of the cell, with alanine eliminated the pH sensing resulting in similar Pf values under acidic and basic conditions. Since hydration is critical for spore switching from the resting to activate state, we suggest that pH regulation of the aquaporins can regulate the initial phase of R. delemar spore germination, followed by germ-tube elongation and host-tissue infection.

Aquaglyceroporin-null trypanosomes display glycerol transport defects and respiratory-inhibitor sensitivity.

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Laura Jeacock

2017-03-01

Full Text Available Aquaglyceroporins (AQPs transport water and glycerol and play important roles in drug-uptake in pathogenic trypanosomatids. For example, AQP2 in the human-infectious African trypanosome, Trypanosoma brucei gambiense, is responsible for melarsoprol and pentamidine-uptake, and melarsoprol treatment-failure has been found to be due to AQP2-defects in these parasites. To further probe the roles of these transporters, we assembled a T. b. brucei strain lacking all three AQP-genes. Triple-null aqp1-2-3 T. b. brucei displayed only a very moderate growth defect in vitro, established infections in mice and recovered effectively from hypotonic-shock. The aqp1-2-3 trypanosomes did, however, display glycerol uptake and efflux defects. They failed to accumulate glycerol or to utilise glycerol as a carbon-source and displayed increased sensitivity to salicylhydroxamic acid (SHAM, octyl gallate or propyl gallate; these inhibitors of trypanosome alternative oxidase (TAO can increase intracellular glycerol to toxic levels. Notably, disruption of AQP2 alone generated cells with glycerol transport defects. Consistent with these findings, AQP2-defective, melarsoprol-resistant clinical isolates were sensitive to the TAO inhibitors, SHAM, propyl gallate and ascofuranone, relative to melarsoprol-sensitive reference strains. We conclude that African trypanosome AQPs are dispensable for viability and osmoregulation but they make important contributions to drug-uptake, glycerol-transport and respiratory-inhibitor sensitivity. We also discuss how the AQP-dependent inverse sensitivity to melarsoprol and respiratory inhibitors described here might be exploited.

Phosphodiesterase-9 (PDE9) inhibition with BAY 73-6691 increases corpus cavernosum relaxations mediated by nitric oxide-cyclic GMP pathway in mice.

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da Silva, F H; Pereira, M N; Franco-Penteado, C F; De Nucci, G; Antunes, E; Claudino, M A

2013-01-01

Phosphodiesterase-9 (PDE9) specifically hydrolyzes cyclic GMP, and was detected in human corpus cavernosum. However, no previous studies explored the selective PDE9 inhibition with BAY 73-6691 in corpus cavernosum relaxations. Therefore, this study aimed to characterize the PDE9 mRNA expression in mice corpus cavernosum, and investigate the effects of BAY 73-6691 in endothelium-dependent and -independent relaxations, along with the nitrergic corpus cavernosum relaxations. Male mice received daily gavage of BAY 73-6691 (or dimethylsulfoxide) at 3 mg kg(-1) per day for 21 days. Relaxant responses to acetylcholine (ACh), nitric oxide (NO) (as acidified sodium nitrite; NaNO2 solution), sildenafil and electrical-field stimulation (EFS) were obtained in corpus cavernosum in control and BAY 73-6691-treated mice. BAY 73-6691 was also added in vitro 30 min before construction of concentration-responses and frequency curves. PDE9A and PDE5 mRNA expression was detected in the mice corpus cavernosum in a similar manner. In vitro addition of BAY 73-6691 neither itself relaxed mice corpus cavernosum nor changed the NaNO2, sildenafil and EFS-induced relaxations. However, in mice treated chronically with BAY 73-6691, the potency (pEC50) values for ACh, NaNO2 and sildenafil were significantly greater compared with control group. The maximal responses (Emax) to NaNO2 and sildenafil were also significantly greater in BAY 73-6691-treated mice. BAY 73-6691 treatment also significantly increased the magnitude and duration of the nitrergic corpus cavernosum relaxations (8-32 Hz). In conclusion, murine corpus cavernosum expresses PDE9 mRNA. Prolonged PDE9 inhibition with BAY 73-6691 amplifies the NO-cGMP-mediated cavernosal responses, and may be of therapeutic value for erectile dysfunction.

Significance of the expression of matrix metalloproteinase-9 (MMP-9) in brain tissue of rat models of experimental intracerebral haemorrhage (ICH)

International Nuclear Information System (INIS)

Wu Jiami; Liu Shengda

2005-01-01

Objective: To study the relationship between the brain tissue expression of MMP-9 and brain water content in rat models of experimental ICH. Methods: Rat models of ICH were prepared with intracerebral (caudate nuclei) injection of autologous noncoagulated blood (50 μl). Animals were sacrificed at 6h, 12h, 24h, 48h, 72h, 120h, lw, 2w and the MMP-9 expressions at the periphery of intracerebral hematoma were examined with immunohisto chemistry. The brain water content was also determined at the same time. Control models were prepared with intracerebral sham injection of normal saline. Results: (1) In the ICH models, the number of MMP-9 positive capillaries at the periphery of hematoma began to rise at 6h (vs that of sham group, P < 0.01 ) with peak at 48h, then gradually dropped. At lwk, the number was still significantly higher than that in the sham group (P <0.01 ). However, there were no expression at 2wk. (2) The brain water content in the ICH group was significantly increased at 12h (vs sham group, P < 0.05) with peak at 72h. At lwk, the brain water content was still significantly higher in the ICH group (P <0.01 ) but at 2wk, the brain water content was about the same in both groups. (3) Animals injected with different amounts of blood (30 μl, 50 μl, 100 μl) showed increased expression of MMP-9 along with the increase of dose (P<0.01). (4) The MMP-9 expression was positively correlated with the brain water content (r=0.8291, P<0.05). Conclusion: In the rat models, MMP-9 expression was activated after ICH. The increase paralleled that of the amount of haemorrhage and brain water content. It was postulated that MMP-9 enhanced development of brain edema through degrading of the blood brain barrier component substances. (authors)

Tamoxifen attenuates development of lithium-induced nephrogenic diabetes insipidus in rats

DEFF Research Database (Denmark)

Tingskov, Stine Julie; Hu, Shan; Frøkiær, Jorgen

2018-01-01

of aquaporin-2 (AQP2), which are essential for water reabsorption of tubular fluid in the collecting duct. Sex hormones have previously been shown to affect the regulation of AQP2, so we tested whether tamoxifen (TAM), a selective estrogen receptor modulator, would attenuate lithium-induced alterations...... on renal water homeostasis. Rats were treated for 14 days with lithium and TAM treatment was initiated one week after onset of lithium administration. Lithium treatment resulted in severe polyuria and reduced AQP2 expression, which was ameliorated by TAM. Consistent with this, TAM attenuated downregulation...... of AQP2 and increased phosphorylation of the cAMP responsive element binding protein (CREB), which induced AQP2 expression, in freshly isolated inner medullary collecting duct suspension prepared from lithium-treated rats. In conclusion, TAM attenuated dose-dependently polyuria, impaired urine...

Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia

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Calloway, Cassandra

2016-01-01

BACKGROUND. Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia. METHODS. Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA4977) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions. RESULTS. Compared with healthy controls, Mt/N and ΔmtDNA4977 frequency were elevated in thalassemia (P = 0.038 and P 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* 40/1 × 107 mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008). CONCLUSION. Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia. FUNDING. This project was supported by Children’s Hospital & Research Center Oakland Institutional Research Award and by the National Center for Advancing Translational Sciences, NIH, through UCSF-CTSI grant UL1 TR000004. PMID:27583305

Aryl hydrocarbon receptor pathway activation enhances gastric cancer cell invasiveness likely through a c-Jun-dependent induction of matrix metalloproteinase-9

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Song Xin

2009-04-01

(10 nmol/L treatment, MMP-9 mRNA expression and activity were significant increased; This TCDD-induced MMP-9 expression and activity increase could be abolished by c-Jun siRNA transfection. Conclusion AhR pathway activation enhances gastric cancer cell invasiveness likely through a c-Jun-dependent induction of MMP-9. Our results provide insight into the mechanism and function of the AhR pathway and its impact on gastric cancer progression.

Agmatine attenuates brain edema through reducing the expression of aquaporin-1 after cerebral ischemia

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Kim, Jae Hwan; Lee, Yong Woo; Park, Kyung Ah; Lee, Won Taek; Lee, Jong Eun

2010-01-01

Brain edema is frequently shown after cerebral ischemia. It is an expansion of brain volume because of increasing water content in brain. It causes to increase mortality after stroke. Agmatine, formed by the decarboxylation of -arginine by arginine decarboxylase, has been shown to be neuroprotective in trauma and ischemia models. The purpose of this study was to investigate the effect of agmatine for brain edema in ischemic brain damage and to evaluate the expression of aquaporins (AQPs). Results showed that agmatine significantly reduced brain swelling volume 22 h after 2 h middle cerebral artery occlusion in mice. Water content in brain tissue was clearly decreased 24 h after ischemic injury by agmatine treatment. Blood–brain barrier (BBB) disruption was diminished with agmatine than without. The expressions of AQPs-1 and -9 were well correlated with brain edema as water channels, were significantly decreased by agmatine treatment. It can thus be suggested that agmatine could attenuate brain edema by limitting BBB disruption and blocking the accumulation of brain water content through lessening the expression of AQP-1 after cerebral ischemia. PMID:20029450

Hypotonicity-induced reduction of aquaporin-2 transcription in mpkCCD cells is independent of the tonicity responsive element, vasopressin, and cAMP.

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Kortenoeven, Marleen L A; van den Brand, Michiel; Wetzels, Jack F M; Deen, Peter M T

2011-04-15

The syndrome of inappropriate antidiuretic hormone secretion is characterized by excessive water uptake and hyponatremia. The extent of hyponatremia, however, is less than anticipated, which is ascribed to a defense mechanism, the vasopressin-escape, and is suggested to involve a tonicity-determined down-regulation of the water channel aquaporin-2 (AQP2). The underlying mechanism, however, is poorly understood. To study this, we used the mouse cortical collecting duct (mpkCCD) cell line. MpkCCD cells, transfected with an AQP2-promoter luciferase construct showed a reduced and increased AQP2 abundance and transcription following culture in hypotonic and hypertonic medium, respectively. This depended on tonicity rather than osmolality and occurred independently of the vasopressin analog dDAVP, cAMP levels, or protein kinase A activity. Although prostaglandins and nitric oxide reduced AQP2 abundance, inhibition of their synthesis did not influence tonicity-induced AQP2 transcription. Also, cells in which the cAMP or tonicity-responsive element (CRE/TonE) in the AQP2-promoter were mutated showed a similar response to hypotonicity. Instead, the tonicity-responsive elements were pin-pointed to nucleotides -283 to -252 and -157 to -126 bp. In conclusion, our data indicate that hypotonicity reduces AQP2 abundance and transcription, which occurs independently of vasopressin, cAMP, and the known TonE and CRE in the AQP2-promoter. Increased prostaglandin and nitric oxide, as found in vivo, may contribute to reduced AQP2 in vasopressin-escape, but do not mediate the effect of hypotonicity on AQP2 transcription. Our data suggest that two novel segments (-283 to -252 and -157 to -126 bp) in the AQP2-promoter mediate the hypotonicity-induced AQP2 down-regulation during vasopressin-escape.

Post-hypercapnic alkalosis is associated with ventilator dependence and increased ICU stay.

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Banga, Amit; Khilnani, G C

2009-12-01

Posthypercapnic alkalosis (PHA) is frequently overlooked as a complication of mechanical ventilation in patients with exacerbation of chronic obstructive pulmonary disease (COPD). The current study was conducted to determine the incidence, risk factors for development and effect on outcome of PHA. Eighty-four patients (62 +/- 11 years, range 42-78 years, M:F 58: 26) with exacerbation of COPD with underlying chronic hypercapnic respiratory failure requiring mechanical ventilation were included in a retrospective fashion. PHA was defined as static or rising serum bicarbonate levels, 72 hours or more after return of PaCO2 to baseline, with concurrent pH > 7.44. Development of PHA was noted in 17 patients (20.2%). Corticosteroid use >or=10 days during the hospital stay was an independent risk factor for development of PHA (Adjusted OR, 95% CI: 9.4, 1.6-55.3; P = 0.013). Development of PHA was associated with an increased incidence of ventilator dependence (64.7% vs. 37.3%, OR, 95% CI: 3.1, 1.1-9.4, P = 0.04) and duration of ICU stay (14.7 +/- 6.7 vs. 9.5 +/- 5.9, P = 0.01) but no increase in hospital mortality (43.3% vs. 41.2%, P = NS). It is concluded that PHA is a common complication in patients with exacerbation of COPD requiring mechanical ventilation and is associated with increased incidence of ventilator dependence and ICU stay.

Rheinanthrone, a metabolite of sennoside A, triggers macrophage activation to decrease aquaporin-3 expression in the colon, causing the laxative effect of rhubarb extract.

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Kon, Risako; Ikarashi, Nobutomo; Nagoya, Chika; Takayama, Tomoko; Kusunoki, Yoshiki; Ishii, Makoto; Ueda, Harumi; Ochiai, Wataru; Machida, Yoshiaki; Sugita, Kazuyuki; Sugiyama, Kiyoshi

2014-02-27

Aquaporin-3 (AQP3) is expressed in mucosal epithelial cells in the colon and is important for regulating fecal water content. We examined the role of AQP3 in the laxative effect of rhubarb extract. After orally administering rhubarb extract or its major component (sennoside A) to rats, the fecal water content, AQP3 expression and prostaglandin E2 (PGE2) concentrations in the colon were examined. The mechanism by which sennoside A decreases the expression of AQP3 was examined using the human colon cancer HT-29 cells and macrophage-derived Raw264.7 cells. During diarrhea by rhubarb extract administration, the PGE2 levels in the colon increased while the AQP3 expression significantly decreased. Similar changes were also observed when sennoside A was administered. When sennoside A or its metabolites, rheinanthrone and rhein were added to Raw264.7 cells, a significant increase in the PGE2 concentration was observed only in cells treated with rheinanthrone. Fifteen minutes after adding PGE2 to the HT-29 cells, the AQP3 expression decreased to approximately 40% of the control. When pretreated with indomethacin, sennoside A neither decreased the AQP3 expression nor induced diarrhea. Sennoside A may decrease AQP3 expression in the colon to inhibit water transport from the luminal to the vascular side, leading to a laxative effect. The decreases in the levels of AQP3 are caused by rheinanthrone, which is a metabolite of sennoside A, this metabolite activates the macrophages in the colon and increases the secretion of PGE2; PGE2 acts as a paracrine factor and decreases AQP3 expression in colon mucosal epithelial cells. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Phosphorylation of rat aquaporin-4 at Ser(111) is not required for channel gating

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Assentoft, Mette; Kaptan, Shreyas; Fenton, Robert A.

2013-01-01

Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4 is theref......Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4...... is therefore of therapeutic interest. Phosphorylation of some aquaporins has been proposed to regulate their water permeability via gating of the channel itself. Protein kinase (PK)-dependent phosphorylation of Ser(111) has been reported to increase the water permeability of AQP4 expressed in an astrocytic...... of activators and inhibitors of PKG and PKA. Mutation of Ser(111) to alanine or aspartate (to prevent or mimic phosphorylation) did not change the water permeability of AQP4. PKG activation had no effect on the water permeability of AQP4 in primary cultures of rat astrocytes. Molecular dynamics simulations...

Blockade of Aquaporin 1 Inhibits Proliferation, Motility, and Metastatic Potential of Mesothelioma In Vitro but not in an In Vivo Model

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Sonja Klebe

2015-01-01

Full Text Available Background. Malignant mesothelioma (MM is an aggressive tumor of the serosal membranes, mostly the pleura. It is related to asbestos exposure and has a poor prognosis. MM has a long latency period, and incidence is predicted to remain stable or increase until 2020. Currently, no biomarkers for a specific targeted therapy are available. Previously, we observed that expression of aquaporin 1 (AQP1 was an indicator of prognosis in two independent cohorts. Here we determine whether AQP1 inhibition has therapeutic potential in the treatment of MM. Methods. Functional studies were performed with H226 cells and primary MM cells harvested from pleural effusions. AQP1 expression and mesothelial phenotype was determined by immunohistochemistry. AQP1 function was inhibited by a pharmacological blocker (AqB050 or AQP1-specific siRNA. Cell proliferation, migration, and anchorage-independent cell growth were assessed. A nude mouse heterotopic xenograft model of MM was utilised for the in vivo studies. Results. Inhibition of AQP1 significantly decreases cell proliferation, metastatic potential, and motility without inducing nonspecific cytotoxicity or increasing apoptosis. In vivo blockade of AQP1 had no biologically significant effect on growth of established tumours. Conclusions. Targeted blockade of AQP1 restricts MM growth and migration in vitro. Further work is warranted to fully evaluate treatment potential in vivo.

Differential expression of aquaporin-3 and aquaporin-5 in pancreatic ductal adenocarcinoma.

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Direito, Inês; Paulino, Jorge; Vigia, Emanuel; Brito, Maria Alexandra; Soveral, Graça

2017-06-01

Aquaporin-5 (AQP5) and -3 (AQP3) are protein channels that showed to be up-regulated in a variety of tumors. Our goal was to investigate the expression pattern of AQP5 and AQP3 in pancreatic ductal adenocarcinomas (PDA) and correlate with cell proliferation, tumor stage and progression, and clinical significance. 35 PDA samples in different stages of differentiation and locations were analyzed by immunohistochemistry for expression of AQP5, AQP3 and several markers of cell proliferation and tumorigenesis. In PDA samples AQP5 was overexpressed in the apical membrane of intercalated and intralobular ductal cells while AQP3 was expressed at the plasma membrane of ductal cells. AQP5 was also found in infiltrative cancer cells in duodenum. Simultaneous overexpression of EGFR, Ki-67, and CK7, with decreased E-cad and increased Vim that characterize epithelial mesenchymal transition, tumor formation and invasion, strongly suggest AQP3 and AQP5 involvement in cell proliferation and transformation. AQP3 overexpression is reinforced in late and more aggressive PDA stages whereas AQP5 is related with tumor differentiation, suggesting it may represent a novel marker for PDA aggressiveness and intestinal infiltration. These findings suggest AQP3 and AQP5 involvement in PDA development and the usefulness of AQP5 in early PDA diagnosis. © 2017 Wiley Periodicals, Inc.

Sixteen-Day Bedrest Significantly Increases Plasma Colloid Osmotic Pressure

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Hargens, Alan R.; Hsieh, S. T.; Murthy, G.; Ballard, R. E.; Convertino, V. A.; Wade, Charles E. (Technical Monitor)

1994-01-01

Upon exposure to microgravity, astronauts lose up to 10% of their total plasma volume, which may contribute to orthostatic intolerance after space flight. Because plasma colloid osmotic pressure (COP) is a primary factor maintaining plasma volume, our objective was to measure time course changes in COP during microgravity simulated by 6 deg. head-down tilt (HDT). Seven healthy male subjects (30-55 years of age) were placed in HDT for 16 days. For the purpose of another study, three of the seven subjects were chosen to exercise on a cycle ergometer on day 16. Blood samples were drawn immediately before bedrest on day 14 of bedrest, 18-24 hours following exercise while all subjects were still in HDT and 1 hour following bedrest termination. Plasma COP was measured in all 20 microliter EDTA-treated samples using an osmometer fitted with a PM 30 membrane. Data were analyzed with paired and unpaired t-tests. Plasma COP on day 14 of bedrest (29.9 +/- 0.69 mmHg) was significantly higher (p less than 0.005) than the control, pre-bedrest value (23.1 +/- 0.76 mmHg). At one hour of upright recovery after HDT, plasma COP remained significantly elevated (exercise: 26.9 +/- 0.87 mmHg; no exercise: 26.3 +/- 0.85 mmHg). Additionally, exercise had no significant effect on plasma COP 18-24 hours following exercise (exercise: 27.8 +/- 1.09 mmHg; no exercise: 27.1 +/- 0.78 mmHg). Our results demonstrate that plasma COP increases significantly with microgravity simulated by HDT. However, preliminary results indicate exercise during HDT does not significantly affect plasma COP.

Aquaporin-4 deletion in mice reduces encephalopathy and brain edema in experimental acute liver failure.

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Rama Rao, Kakulavarapu V; Verkman, A S; Curtis, Kevin M; Norenberg, Michael D

2014-03-01

Brain edema and associated astrocyte swelling leading to increased intracranial pressure are hallmarks of acute liver failure (ALF). Elevated blood and brain levels of ammonia have been implicated in the development of brain edema in ALF. Cultured astrocytes treated with ammonia have been shown to undergo cell swelling and such swelling was associated with an increase in the plasma membrane expression of aquaporin-4 (AQP4) protein. Further, silencing the AQP4 gene in cultured astrocytes was shown to prevent the ammonia-induced cell swelling. Here, we examined the evolution of brain edema in AQP4-null mice and their wild type counterparts (WT-mice) in different models of ALF induced by thioacetamide (TAA) or acetaminophen (APAP). Induction of ALF with TAA or APAP significantly increased brain water content in WT mice (by 1.6% ± 0.3 and 2.3 ± 0.4%, respectively). AQP4 protein was significantly increased in brain plasma membranes of WT mice with ALF induced by either TAA or APAP. In contrast to WT-mice, brain water content did not increase in AQP4-null mice. Additionally, AQP4-null mice treated with either TAA or APAP showed a remarkably lesser degree of neurological deficits as compared to WT mice; the latter displayed an inability to maintain proper gait, and demonstrated a markedly reduced exploratory behavior, with the mice remaining in one corner of the cage with its head tilted downwards. These results support a central role of AQP4 in the brain edema associated with ALF. Published by Elsevier Inc.

Platelet-activating factor increases platelet-dependent glycoconjugate secretion from tracheal submucosal gland

International Nuclear Information System (INIS)

Sasaki, T.; Shimura, S.; Ikeda, K.; Sasaki, H.; Takishima, T.

1989-01-01

Using isolated glands from feline trachea, we examined the effect of platelet-activating factor (PAF) on radiolabeled glycoconjugate release and glandular contraction by measuring induced tension in the absence or presence of platelets. PAF alone did not produce any significant glandular contraction nor any significant change in glycoconjugate release from isolated glands. In the presence of purified platelets containing no plasma, PAF (10(-8) to 10(-5) M) produced significant glycoconjugate secretion in a dose-dependent fashion, but it produced no significant glandular contraction. PAF-evoked glycoconjugate secretion was time dependent, reaching a peak response of 277% of control 15-30 min after the exposure of isolated glands to 10(-5) M PAF in the presence of platelets and returning to 135% of controls at 2 h. Platelets alone did not produce any significant stimulation in glycoconjugate release. CV-3988, a known PAF antagonist, inhibited the secretory response to PAF. Methysergide, a known antagonist to receptors for 5-hydroxytryptamine, did not alter PAF-evoked glycoconjugate secretion. Both indomethacin and SQ 29,548, a thromboxane receptor antagonist, abolished the PAF-evoked glycoconjugate secretion from isolated submucosal glands. Epithiomethanothromboxane A2, a stable thromboxane A2 analogue, produced a significant increase in glycoconjugate secretion in a dose-dependent fashion. These findings indicate that PAF increases glycoconjugate release in the presence of platelets and that the increase is dependent on some aspect of platelet function, namely thromboxane generation

Intermittent Fasting Protects against Alzheimer's Disease Possible through Restoring Aquaporin-4 Polarity.

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Zhang, Jingzhu; Zhan, Zhipeng; Li, Xinhui; Xing, Aiping; Jiang, Congmin; Chen, Yanqiu; Shi, Wanying; An, Li

2017-01-01

The impairment of amyloid-β (Aβ) clearance in the brain plays a causative role in Alzheimer's disease (AD). Polarity distribution of aquaporin-4 (AQP4) is important to remove Aβ from brain. AQP4 polarity can be influenced by the ratio of two AQP4 isoforms M1 and M23 (AQP4-M1/M23), however, it is unknown whether the ratio of AQP4-M1/M23 changes in AD. Histone deacetylase 3 has been reported to be significantly increased in AD brain. Moreover, evidence indicated that microRNA-130a (miR-130a) possibly mediates the regulation of histone deacetylase 3 on AQP4-M1/M23 ratio by repressing the transcriptional activity of AQP4-M1 in AD. This study aimed to investigate whether intermittent fasting (IF), increasing the level of an endogenous histone deacetylases inhibitor β-hydroxybutyrate, restores AQP4 polarity via miR-130a mediated reduction of AQP4-M1/M23 ratio in protection against AD. The results showed that IF ameliorated cognitive dysfunction, prevented brain from Aβ deposition, and restored the AQP4 polarity in a mouse model of AD (APP/PS1 double-transgenic mice). Additionally, IF down-regulated the expression of AQP4-M1 and histone deacetylase 3, reduced AQP4-M1/M23 ratio, and increased miR-130a expression in the cerebral cortex of APP/PS1 mice. In vitro , β-hydroxybutyrate was found to down-regulate the expression of AQP4-M1 and histone deacetylase 3, reduce AQP4-M1/M23 ratio, and increase AQP4-M23 and miR-130a expression in 2 μM Aβ-treated U251 cells. Interestingly, on the contrary to the result observed in 2 μM Aβ-treated cells, AQP4 expression was obviously decreased in cells exposed to 10 μM Aβ. miR-130a mimic decreased the expression of AQP4-M1 and the ratio of AQP4-M1/M23, as well as silencing histone deacetylase 3 caused the up-regulation of AQP4 and miR-130a, and the reduction of AQP4-M1/M23 ratio in U251 cells. In conclusion, IF exhibits beneficial effects against AD. The mechanism may be associated with recovery of AQP4 polarity, resulting from

Intermittent Fasting Protects against Alzheimer’s Disease Possible through Restoring Aquaporin-4 Polarity

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Jingzhu Zhang

2017-11-01

Full Text Available The impairment of amyloid-β (Aβ clearance in the brain plays a causative role in Alzheimer’s disease (AD. Polarity distribution of aquaporin-4 (AQP4 is important to remove Aβ from brain. AQP4 polarity can be influenced by the ratio of two AQP4 isoforms M1 and M23 (AQP4-M1/M23, however, it is unknown whether the ratio of AQP4-M1/M23 changes in AD. Histone deacetylase 3 has been reported to be significantly increased in AD brain. Moreover, evidence indicated that microRNA-130a (miR-130a possibly mediates the regulation of histone deacetylase 3 on AQP4-M1/M23 ratio by repressing the transcriptional activity of AQP4-M1 in AD. This study aimed to investigate whether intermittent fasting (IF, increasing the level of an endogenous histone deacetylases inhibitor β-hydroxybutyrate, restores AQP4 polarity via miR-130a mediated reduction of AQP4-M1/M23 ratio in protection against AD. The results showed that IF ameliorated cognitive dysfunction, prevented brain from Aβ deposition, and restored the AQP4 polarity in a mouse model of AD (APP/PS1 double-transgenic mice. Additionally, IF down-regulated the expression of AQP4-M1 and histone deacetylase 3, reduced AQP4-M1/M23 ratio, and increased miR-130a expression in the cerebral cortex of APP/PS1 mice. In vitro, β-hydroxybutyrate was found to down-regulate the expression of AQP4-M1 and histone deacetylase 3, reduce AQP4-M1/M23 ratio, and increase AQP4-M23 and miR-130a expression in 2 μM Aβ-treated U251 cells. Interestingly, on the contrary to the result observed in 2 μM Aβ-treated cells, AQP4 expression was obviously decreased in cells exposed to 10 μM Aβ. miR-130a mimic decreased the expression of AQP4-M1 and the ratio of AQP4-M1/M23, as well as silencing histone deacetylase 3 caused the up-regulation of AQP4 and miR-130a, and the reduction of AQP4-M1/M23 ratio in U251 cells. In conclusion, IF exhibits beneficial effects against AD. The mechanism may be associated with recovery of AQP4 polarity

Effects of Repeated Administration of Pilocarpine and Isoproterenol on Aquaporin-5 Expression in Rat Salivary Glands

International Nuclear Information System (INIS)

Susa, Taketo; Sawai, Nobuhiko; Aoki, Takeo; Iizuka-Kogo, Akiko; Kogo, Hiroshi; Negishi, Akihide; Yokoo, Satoshi; Takata, Kuniaki; Matsuzaki, Toshiyuki

2013-01-01

Aquaporins are water channel proteins which enable rapid water movement across the plasma membrane. Aquaporin-5 (AQP5) is the major aquaporin and is expressed on the apical membrane of salivary gland acinar cells. We examined the effects of repeated administration of pilocarpine, a clinically useful stimulant for salivary fluid secretion, and isoproterenol (IPR), a stimulant for salivary protein secretion, on the abundance of AQP5 protein in rat salivary glands by immunofluorescence microscopy and semi-quantitative immunoblotting. Unexpectedly AQP5 was decreased in pilocarpine-administered salivary glands, in which fluid secretion must be highly stimulated, implying that AQP5 might not be required for fluid secretion at least in pilocarpine-administered state. The abundance of AQP5, on the other hand, was found to be significantly increased in IPR-administered submandibular and parotid glands. To address the possible mechanism of the elevation of AQP5 abundance in IPR-administered animals, changes of AQP5 level in fasting animals, in which the exocytotic events are reduced, were examined. AQP5 was found to be decreased in fasting animals as expected. These results suggested that the elevation of cAMP and/or frequent exocytotic events could increase AQP5 protein. AQP5 expression seems to be easily changed by salivary stimulants, although these changes do not always reflect the ability in salivary fluid secretion

Natural killer cell-dependent anti-fibrotic pathway in liver injury via Toll-like receptor-9.

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Lina Abu-Tair

Full Text Available The toll-like receptor-9 (TLR9 agonist cytosine phosphate guanine (CpG, activates hepatic stellate cells (HSCs and mediates fibrosis. We investigated the TLR9 effects on lymphocyte/HSCs interactions. Liver fibrosis was induced in wild-type (WT mice by intra-peritoneal carbon-tetrachloride (CCl4 induction for 6 weeks. Fibrotic groups were intravenously treated by a vehicle versus CpG along last 2 weeks. Compared to vehicle-treated fibrotic WT, the in-vivo CpG-treatment significantly attenuated hepatic fibrosis and inflammation, associated with decreased CD8 and increased NK liver cells. In-vitro, co-cultures with vehicle-treated fibrotic NK cells increased HSCs proliferation (P<0.001 while their CpG-treated counterparts achieved a significant decrease. To investigate the role of lymphocytes, TLR9(-/- mice induced-hepatic fibrosis were used. Although TLR9(-/- mice manifested lower fibrotic profile as compared to their wild-type (WT counterparts, senescence (SA-β-Gal activity in the liver and ALT serum levels were significantly greater. In an adoptive transfer model; irradiated WT and TLR9(-/- recipients were reconstituted with naïve WT or TLR9(-/- lymphocytes. The adoptive transfer of TLR9(-/- versus WT lymphocytes led to increased fibrosis of WT recipients. TLR9(-/- fibrotic recipients reconstituted with TLR9(-/- or WT lymphocytes showed no changes in hepatic fibrosis severity or ALT serum levels. TLR9 activation had inconsistent effects on lymphocytes and HSCs. The net balance of TLR9 activation in WT, displayed significant anti-fibrotic activity, accompanied by CD8 suppression and increased NK-cells, activity and adherence to HSCs. The pro-fibrotic and pro-inflammatory properties of TLR9(-/- lymphocytes fail to activate HSCs with an early senescence in TLR9(-/- mice.

Aquaporin 4 is a Ubiquitously Expressed Isoform in the Dogfish (Squalus acanthias) Shark.

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Cutler, Christopher P; Maciver, Bryce; Cramb, Gordon; Zeidel, Mark

2011-01-01

The dogfish ortholog of aquaporin 4 (AQP4) was amplified from cDNA using degenerate PCR followed by cloning and sequencing. The complete coding region was then obtained using 5' and 3' RACE techniques. Alignment of the sequence with AQP4 amino acid sequences from other species showed that dogfish AQP4 has high levels (up to 65.3%) of homology with higher vertebrate sequences but lower levels of homology to Agnathan (38.2%) or teleost (57.5%) fish sequences. Northern blotting indicated that the dogfish mRNA was approximately 3.2 kb and was highly expressed in the rectal gland (a shark fluid secretory organ). Semi-quantitative PCR further indicates that AQP4 is ubiquitous, being expressed in all tissues measured but at low levels in certain tissues, where the level in liver > gill >  intestine. Manipulation of the external environmental salinity of groups of dogfish showed that when fish were acclimated in stages to 120% seawater (SW) or 75% SW, there was no change in AQP4 mRNA expression in either rectal gland, kidney, or esophagus/cardiac stomach. Whereas quantitative PCR experiments using the RNA samples from the same experiment, showed a significant 63.1% lower abundance of gill AQP4 mRNA expression in 120% SW-acclimated dogfish. The function of dogfish AQP4 was also determined by measuring the effect of the AQP4 expression in Xenopus laevis oocytes. Dogfish AQP4 expressing-oocytes, exhibited significantly increased osmotic water permeability (P(f)) compared to controls, and this was invariant with pH. Permeability was not significantly reduced by treatment of oocytes with mercury chloride, as is also the case with AQP4 in other species. Similarly AQP4 expressing-oocytes did not exhibit enhanced urea or glycerol permeability, which is also consistent with the water-selective property of AQP4 in other species.

Aquaporin 4 is a ubiquitously expressed isoform in the dogfish (Squalus acanthias shark.

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Christopher P Cutler

2012-01-01

Full Text Available The dogfish orthologue of aquaporin 4 (AQP4 was amplified from cDNA using degenerate PCR followed by cloning and sequencing. The complete coding region was then obtained using 5’ and 3’ RACE techniques. Alignment of the sequence with AQP4 amino acid sequences from other species showed that dogfish AQP4 has high levels (up to 65.3% of homology with higher vertebrate sequences but lower levels of homology to agnathan (38.2% or teleost (57.5% fish sequences. Northern blotting indicated that the dogfish mRNA was approximately 3.2 kb and was highly expressed in the rectal gland (a shark fluid secretory organ. Semi-quantitative PCR further indicates that AQP4 is ubiquitous, being expressed in all tissues measured but at low levels in certain tissues, where the level in liver>gill> intestine. Manipulation of the external environmental salinity of groups of dogfish showed that when fish were acclimated in stages to 120% seawater (SW or 75% SW, there was no change in AQP4 mRNA expression in either rectal gland, kidney or esophagus/cardiac stomach. Whereas quantitative PCR experiments using the RNA samples from the same experiment, showed a significant 63.1% lower abundance of gill AQP4 mRNA expression in 120% SW-acclimated dogfish. The function of dogfish AQP4 was also determined by measuring the effect of the AQP4 expression in Xenopus laevis oocytes. Dogfish AQP4 expressingoocytes, exhibited significantly increased osmotic water permeability (Pf compared to controls, and this was invariant with pH. Permeability was not significantly reduced by treatment of oocytes with mercury chloride, as is also the case with AQP4 in other species. Similarly AQP4 expressing oocytes did not exhibit enhanced urea or glycerol permeability, which is also consistent with the water-selective property of AQP4 in other species.

42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Payments: Stipends; dependency allowances; travel... FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.9 Payments: Stipends; dependency allowances; travel allowances. Payments for stipends, dependency allowances, and the travel allowances...

The role of renal aquaporin 2 in the alleviation of dehydration associated with diabetic polyuria in KKAy mice.

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Satake, Masako; Ikarashi, Nobutomo; Ichikawa, Yuhei; Maniwa, Ayaka; Toda, Takahiro; Ito, Kiyomi; Ochiai, Wataru; Sugiyama, Kiyoshi

2010-10-09

Polyuria is a symptom that appears in association with diabetes mellitus. Because sustained polyuria causes serious dehydration, it is believed that the body has a compensating mechanism to alleviate dehydration. In the present study, the role of renal aquaporin 2 (AQP2) in the compensating mechanism was investigated in KKAy mice, a type 2 diabetes model. The renal AQP2 expression levels in KKAy mice aged between 5 and 24 weeks were determined using Western blotting. The hypothalamic vasopressin mRNA expression levels also were measured by real-time RT-PCR. Insulin was subcutaneously administered to 11-week-old KKAy mice twice a day for 7 days. After insulin treatment, the renal AQP2 protein expression and the hypothalamic vasopressin mRNA expression were measured. The urinary volumes of 5- and 12-week-old KKAy mice were 1.5 ± 0.3 mL and 9.5 ± 1.2 mL, respectively. The inner medullary AQP2 protein expression of 12-week-old KKAy mice was approximately 2.5-fold higher than that of 5-week-old KKAy mice. The hypothalamic vasopressin mRNA expression of 12-week-old KKAy mice was approximately twice that of 5-week-old KKAy mice. Insulin treatment in KKAy mice resulted in a significant reduction in the plasma glucose level, urinary volume, and inner medullary AQP2 protein and hypothalamic vasopressin mRNA expression. The present study demonstrated that AQP2 is a renal functional molecule of vasopressin that controls urinary volume and that AQP2 in the kidney increases to alleviate dehydration due to type 2 diabetes with polyuria. Copyright © 2010 Elsevier Inc. All rights reserved.

Role of Aquaporin-4 in Airspace-to-Capillary Water Permeability in Intact Mouse Lung Measured by a Novel Gravimetric Method

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Song, Yuanlin; Ma, Tonghui; Matthay, Michael A.; Verkman, A.S.

2000-01-01

The mammalian peripheral lung contains at least three aquaporin (AQP) water channels: AQP1 in microvascular endothelia, AQP4 in airway epithelia, and AQP5 in alveolar epithelia. In this study, we determined the role of AQP4 in airspace-to-capillary water transport by comparing water permeability in wild-type mice and transgenic null mice lacking AQP1, AQP4, or AQP1/AQP4 together. An apparatus was constructed to measure lung weight continuously during pulmonary artery perfusion of isolated mouse lungs. Osmotically induced water flux (Jv) between the airspace and capillary compartments was measured from the kinetics of lung weight change in saline-filled lungs in response to changes in perfusate osmolality. Jv in wild-type mice varied linearly with osmotic gradient size (4.4 × 10−5 cm3 s−1 mOsm−1) and was symmetric, independent of perfusate osmolyte size, weakly temperature dependent, and decreased 11-fold by AQP1 deletion. Transcapillary osmotic water permeability was greatly reduced by AQP1 deletion, as measured by the same method except that the airspace saline was replaced by an inert perfluorocarbon. Hydrostatically induced lung edema was characterized by lung weight changes in response to changes in pulmonary arterial inflow or pulmonary venous outflow pressure. At 5 cm H2O outflow pressure, the filtration coefficient was 4.7 cm3 s−1 mOsm−1 and reduced 1.4-fold by AQP1 deletion. To study the role of AQP4 in lung water transport, AQP1/AQP4 double knockout mice were generated by crossbreeding of AQP1 and AQP4 null mice. Jv were (cm3 s−1 mOsm−1 × 10−5, SEM, n = 7–12 mice): 3.8 ± 0.4 (wild type), 0.35 ± 0.02 (AQP1 null), 3.7 ± 0.4 (AQP4 null), and 0.25 ± 0.01 (AQP1/AQP4 null). The significant reduction in P f in AQP1 vs. AQP1/AQP4 null mice was confirmed by an independent pleural surface fluorescence method showing a 1.6 ± 0.2-fold (SEM, five mice) reduced P f in the AQP1/AQP4 double knockout mice vs. AQP1 null mice. These results establish

Aquaporin-4 mediates communication between astrocyte and microglia: Implications of neuroinflammation in experimental Parkinson's disease.

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Sun, H; Liang, R; Yang, B; Zhou, Y; Liu, M; Fang, F; Ding, J; Fan, Y; Hu, G

2016-03-11

Aquaporin-4 (AQP4), a water-selective membrane transport protein, is up-regulated in astrocytes in various inflammatory lesions, including Parkinson disease (PD). However, the exact functional roles of AQP4 in neuroinflammation remain unknown. In the present study, we investigated how AQP4 participates in the neuroinflammation of PD using AQP4 knockout (KO) mice and astrocyte-microglial co-cultures. We found that AQP4 KO mice exhibited increased basal and inducible canonical NF-κB activity, and showed significantly enhanced gliosis (astrocytosis and microgliosis) in chronic MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)/probenecid PD models, companying with the increase in the production of IL-1β and TNF-α in the midbrain. Similarly, AQP4 deficiency augmented the activation of the NF-κB pathway and the production of IL-1β and TNF-α in midbrain astrocyte cultures treated with MPP(+) (1-methyl-4-phenylpyridinium). Furthermore, AQP4 deficiency promoted activation of microglial cells in the co-cultured system. Our data provide the first evidence that AQP4 modulates astrocyte-to-microglia communication in neuroinflammation, although its effect on astrocyte inflammatory activation remains to be explored. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Increased frequency of retinopathy of prematurity over the last decade and significant regional differences.

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Holmström, Gerd; Tornqvist, Kristina; Al-Hawasi, Abbas; Nilsson, Åsa; Wallin, Agneta; Hellström, Ann

2018-03-01

Retinopathy of prematurity (ROP) causes childhood blindness globally in prematurely born infants. Although increased levels of oxygen supply lead to increased survival and reduced frequency of cerebral palsy, increased incidence of ROP is reported. With the help of a Swedish register for ROP, SWEDROP, national and regional incidences of ROP and frequencies of treatment were evaluated from 2008 to 2015 (n = 5734), as well as before and after targets of provided oxygen changed from 85-89% to 91-95% in 2014. Retinopathy of prematurity (ROP) was found in 31.9% (1829/5734) of all infants with a gestational age (GA) of <31 weeks at birth and 5.7% of the infants (329/5734) had been treated for ROP. Analyses of the national data revealed an increased incidence of ROP during the 8-year study period (p = 0.003), but there was no significant increase in the frequency of treatment. There were significant differences between the seven health regions of Sweden, regarding both incidence of ROP and frequency of treatment (p < 0.001). Comparison of regional data before and after the new oxygen targets revealed a significant increase in treated ROP in one region [OR: 2.24 (CI: 1.11-4.49), p = 0.024] and a borderline increase in one other [OR: 3.08 (CI: 0.99-9.60), p = 0.052]. The Swedish national ROP register revealed an increased incidence of ROP during an 8-year period and significant regional differences regarding the incidence of ROP and frequency of treatment. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Effects of dietary nitrogen concentration on messenger RNA expression and protein abundance of urea transporter-B and aquaporins in ruminal papillae from lactating Holstein cows

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Røjen, Betina Amdisen; Poulsen, Søren Brandt; Theil, Peter Kappel

2011-01-01

To test the hypothesis that dietary N concentrations affect gut epithelial urea transport by modifying the expression of urea transporter B (UT-B) and aquaporins (AQP), the mRNA expression and protein abundance of UT-B and AQP3, AQP7, AQP8, and AQP10 were investigated in ruminal papillae from 9...... lactating dairy cows. Ruminal papillae were harvested from cows fed low N (12.9% crude protein) and high N (17.1% crude protein) diets in a crossover design with 21-d periods. The mRNA expression was determined by real-time reverse transcription-PCR and protein abundance by immunoblotting. The m......RNA expression of UT-B was not affected by dietary treatment, whereas mRNA expression of AQP3, 7, and 10 were greater in the high N compared with the low N fed cows. Using peptide-derived rabbit antibodies to cow AQP3, 7, and 8, immunoblotting revealed bands of approximately 27, 27, and 24 kDa in ruminal...

Water fluxes through aquaporin-9 prime epithelial cells for rapid wound healing

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Karlsson, T.; Lagerholm, B. C.; Vikstrom, E.

2013-01-01

Cells move along surfaces both as single cells and multi-cellular units. Recent research points toward pivotal roles for water flux through aquaporins (AQPs) in single cell migration. Their expression is known to facilitate this process by promoting rapid shape changes. However, little is known...... wound healing based on AQP-induced swelling and expansion of the monolayer. (C) 2012 Elsevier Inc. All rights reserved....

Downregulation of aquaporin-1 in alveolar microvessels in lungs adapted to chronic heart failure

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Müllertz, Katrine M; Strøm, Claes; Trautner, Simon

2011-01-01

The threshold pressure for lung edema formation is increased in severe chronic heart failure (CHF) due to reduced microvascular permeability. The water channel aquaporin-1 (AQP1) is present in the pulmonary microvascular endothelium, and a number of studies suggest the importance of AQP1 as a mol......The threshold pressure for lung edema formation is increased in severe chronic heart failure (CHF) due to reduced microvascular permeability. The water channel aquaporin-1 (AQP1) is present in the pulmonary microvascular endothelium, and a number of studies suggest the importance of AQP1...... as a molecular determinant of pulmonary microvascular water transport. The present study examined the abundance and localization of AQP1 in lungs from rats with CHF. We used two different models of CHF: ligation of the left anterior descending coronary artery (LAD ligation) and aorta-banding (AB). Sham......-operated rats served as controls. Echocardiographic verification of left ventricular dysfunction, enhanced left ventricular end-diastolic pressure, and right ventricular hypertrophy confirmed the presence of CHF. Western blotting of whole-lung homogenates revealed significant downregulation of AQP1 in LAD...

Meta-Analysis Reveals Significant Association of the 3'-UTR VNTR in SLC6A3 with Alcohol Dependence.

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Ma, Yunlong; Fan, Rongli; Li, Ming D

2016-07-01

Although many studies have analyzed the association of 3'-untranslated region variable-number tandem repeat (VNTR) polymorphism in SLC6A3 with alcohol dependence (AD), the results remain controversial. This study aimed to determine whether this variant indeed has any genetic effect on AD by integrating 17 reported studies with 5,929 participants included. The A9-dominant genetic model that considers A9-repeat and non-A9 repeat as 2 genotypes and compared their frequencies in alcoholics with that in controls was adopted. Considering the potential influence of ethnicity, differences in diagnostic criteria of AD, and alcoholic subgroups, stratified meta-analyses were conducted. There existed no evidence for the presence of heterogeneity among the studied samples, indicating the results under the fixed-effects model are acceptable. We found a significant association of VNTR A9 genotypes with AD in all ethnic populations (pooled odds ratio [OR] 1.12; 95% confidence interval [CI] 1.00, 1.25; p = 0.045) and the Caucasian population (pooled OR 1.15; 95% CI 1.01, 1.31; p = 0.036). We also found VNTR A9 genotypes to be significantly associated with alcoholism as defined by the DSM-IV criteria (pooled OR 1.18; 95% CI 1.03, 1.36; p = 0.02). Further, we found a significant association between VNTR A9 genotypes and alcoholism associated with alcohol withdrawal seizure or delirium tremens (pooled OR 1.55; 95% CI 1.24, 1.92; p = 1.0 × 10(-4) ). In all these meta-analyses, no evidence of publication bias was detected. We concluded that the VNTR polymorphism has an important role in the etiology of AD, and individuals with at least 1 A9 allele are more likely to be dependent on alcohol than persons carrying the non-A9 allele. Copyright © 2016 by the Research Society on Alcoholism.

Fluoxetine requires the endfeet protein aquaporin-4 to enhance plasticity of astrocyte processes

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Barbara eDi Benedetto

2016-02-01

Full Text Available Morphological alterations in astrocytes are characteristic for post mortem brains of patients affected by major depressive disorder (MDD. Recently, a significant reduction in the coverage of blood vessels (BVs by aquaporin-4 (AQP-4-positive astrocyte endfeet has been shown in the prefrontal cortex (PFC of MDD patients, suggesting that either alterations in the morphology of endfeet or in AQP-4 distribution might be responsible for the disease phenotype or constitute a consequence of its progress. Antidepressant drugs (ADs regulate the expression of several proteins, including astrocyte-specific ones. Thus, they may target AQP-4 to induce morphological changes in astrocytes and restore their proper shape or relocate AQP-4 to endfeet. Using an animal model of depression, rats selectively bred for high anxiety-like behavior (HAB, we confirmed a reduced coverage of BVs in the adult PFC by AQP-4-immunoreactive (AQP-4-IR astrocyte processes with respect to nonselected Wistar rats (NAB, thereby validating it for our study. A further evaluation of the morphology of astrocyte in brain slices (ex vivo and in vitro using an antibody against the astrocyte-specific cytoskeletal protein glial fibrillary acidic protein (GFAP revealed that HAB astrocytes extended less processes than NAB cells. Furthermore, short-term drug treatment in vitro with the AD fluoxetine (FLX was sufficient to increase the plasticity of astrocyte processes, enhancing their number in NAB-derived cells and recovering their basal number in HAB-derived cells. This enhanced FLX-dependent plasticity occurred, however, only in the presence of intact AQP-4, as demonstrated by the lack of effect after the downregulation of AQP-4 with RNAi in both NAB and HAB cells. Nonetheless, a similar short-term treatment did neither modulate the coverage of BVs with AQP-4-positive astrocyte endfeet in NAB nor in HAB rats, although dosage and time of treatment were sufficient to fully recover GFAP expression

Association between increased EEG signal complexity and cannabis dependence.

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Laprevote, Vincent; Bon, Laura; Krieg, Julien; Schwitzer, Thomas; Bourion-Bedes, Stéphanie; Maillard, Louis; Schwan, Raymund

2017-12-01

Both acute and regular cannabis use affects the functioning of the brain. While several studies have demonstrated that regular cannabis use can impair the capacity to synchronize neural assemblies during specific tasks, less is known about spontaneous brain activity. This can be explored by measuring EEG complexity, which reflects the spontaneous variability of human brain activity. A recent study has shown that acute cannabis use can affect that complexity. Since the characteristics of cannabis use can affect the impact on brain functioning, this study sets out to measure EEG complexity in regular cannabis users with or without dependence, in comparison with healthy controls. We recruited 26 healthy controls, 25 cannabis users without cannabis dependence and 14 cannabis users with cannabis dependence, based on DSM IV TR criteria. The EEG signal was extracted from at least 250 epochs of the 500ms pre-stimulation phase during a visual evoked potential paradigm. Brain complexity was estimated using Lempel-Ziv Complexity (LZC), which was compared across groups by non-parametric Kruskall-Wallis ANOVA. The analysis revealed a significant difference between the groups, with higher LZC in participants with cannabis dependence than in non-dependent cannabis users. There was no specific localization of this effect across electrodes. We showed that cannabis dependence is associated to an increased spontaneous brain complexity in regular users. This result is in line with previous results in acute cannabis users. It may reflect increased randomness of neural activity in cannabis dependence. Future studies should explore whether this effect is permanent or diminishes with cannabis cessation. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

Albumin induces upregulation of matrix metalloproteinase-9 in astrocytes via MAPK and reactive oxygen species-dependent pathways

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Ranaivo Hantamalala

2012-04-01

Full Text Available Abstract Background Astrocytes are an integral component of the blood–brain barrier (BBB which may be compromised by ischemic or traumatic brain injury. In response to trauma, astrocytes increase expression of the endopeptidase matrix metalloproteinase (MMP-9. Compromise of the BBB leads to the infiltration of fluid and blood-derived proteins including albumin into the brain parenchyma. Albumin has been previously shown to activate astrocytes and induce the production of inflammatory mediators. The effect of albumin on MMP-9 activation in astrocytes is not known. We investigated the molecular mechanisms underlying the production of MMP-9 by albumin in astrocytes. Methods Primary enriched astrocyte cultures were used to investigate the effects of exposure to albumin on the release of MMP-9. MMP-9 expression was analyzed by zymography. The involvement of mitogen-activated protein kinase (MAPK, reactive oxygen species (ROS and the TGF-β receptor-dependent pathways were investigated using pharmacological inhibitors. The production of ROS was observed by dichlorodihydrofluorescein diacetate fluorescence. The level of the MMP-9 inhibitor tissue inhibitor of metalloproteinase (TIMP-1 produced by astrocytes was measured by ELISA. Results We found that albumin induces a time-dependent release of MMP-9 via the activation of p38 MAPK and extracellular signal regulated kinase, but not Jun kinase. Albumin-induced MMP-9 production also involves ROS production upstream of the MAPK pathways. However, albumin-induced increase in MMP-9 is independent of the TGF-β receptor, previously described as a receptor for albumin. Albumin also induces an increase in TIMP-1 via an undetermined mechanism. Conclusions These results link albumin (acting through ROS and the p38 MAPK to the activation of MMP-9 in astrocytes. Numerous studies identify a role for MMP-9 in the mechanisms of compromise of the BBB, epileptogenesis, or synaptic remodeling after ischemia or

Sugar and hexokinase suppress expression of PIP aquaporins and reduce leaf hydraulics that preserves leaf water potential.

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Kelly, Gilor; Sade, Nir; Doron-Faigenboim, Adi; Lerner, Stephen; Shatil-Cohen, Arava; Yeselson, Yelena; Egbaria, Aiman; Kottapalli, Jayaram; Schaffer, Arthur A; Moshelion, Menachem; Granot, David

2017-07-01

Sugars affect central aspects of plant physiology, including photosynthesis, stomatal behavior and the loss of water through the stomata. Yet, the potential effects of sugars on plant aquaporins (AQPs) and water conductance have not been examined. We used database and transcriptional analyses, as well as cellular and whole-plant functional techniques to examine the link between sugar-related genes and AQPs. Database analyses revealed a high level of correlation between the expression of AQPs and that of sugar-related genes, including the Arabidopsis hexokinases 1 (AtHXK1). Increased expression of AtHXK1, as well as the addition of its primary substrate, glucose (Glc), repressed the expression of 10 AQPs from the plasma membrane-intrinsic proteins (PIP) subfamily (PIP-AQPs) and induced the expression of two stress-related PIP-AQPs. The osmotic water permeability of mesophyll protoplasts of AtHXK1-expressing plants and the leaf hydraulic conductance of those plants were significantly reduced, in line with the decreased expression of PIP-AQPs. Conversely, hxk1 mutants demonstrated a higher level of hydraulic conductance, with increased water potential in their leaves. In addition, the presence of Glc reduced leaf water potential, as compared with an osmotic control, indicating that Glc reduces the movement of water from the xylem into the mesophyll. The production of sugars entails a significant loss of water and these results suggest that sugars and AtHXK1 affect the expression of AQP genes and reduce leaf water conductance, to coordinate sugar levels with the loss of water through transpiration. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Molar concentrations of sorbitol and polyethylene glycol inhibit the Plasmodium aquaglyceroporin but not that of E. coli: involvement of the channel vestibules.

Science.gov (United States)

Song, Jie; Almasalmeh, Abdulnasser; Krenc, Dawid; Beitz, Eric

2012-05-01

The aquaglyceroporins of Escherichia coli, EcGlpF, and of Plasmodium falciparum, PfAQP, are probably the best characterized members of the solute-conducting aquaporin (AQP) subfamily. Their crystal structures have been elucidated and numerous experimental and theoretical analyses have been conducted. However, opposing reports on their rates of water permeability require clarification. Hence, we expressed EcGlpF and PfAQP in yeast, prepared protoplasts, and compared water and glycerol permeability of both aquaglyceroporins in the presence of different osmolytes, i.e. sucrose, sorbitol, PEG300, and glycerol. We found that water permeability of PfAQP strongly depends on the external osmolyte, with full inhibition by sorbitol, and increasing water permeability when glycerol, PEG300, and sucrose were used. EcGlpF expression did not enhance water permeability over that of non-expressing control protoplasts regardless of the osmolyte. Glycerol permeability of PfAQP was also inhibited by sorbitol, but to a smaller extent, whereas EcGlpF conducted glycerol independently of the osmolyte. Mixtures of glycerol and urea passed PfAQP equally well under isosmotic conditions, whereas under hypertonic conditions in a countercurrent with water, glycerol was clearly preferred over urea. We conclude that PfAQP has high and EcGlpF low water permeability, and explain the inhibiting effect of sorbitol on PfAQP by its binding to the extracellular vestibule. The preference for glycerol under hypertonic conditions implies that in a physiological setting, PfAQP mainly acts as a water/glycerol channel rather than a urea facilitator. Copyright © 2012 Elsevier B.V. All rights reserved.

Vasopressin-dependent short-term regulation of aquaporin 4 expressed in Xenopus oocytes

DEFF Research Database (Denmark)

Moeller, H B; Fenton, R A; Zeuthen, T

2009-01-01

Aquaporin 4 (AQP4) is abundantly expressed in the perivascular glial endfeet in the central nervous system (CNS), where it is involved in the exchange of fluids between blood and brain. At this location, AQP4 contributes to the formation and/or the absorption of the brain edema that may arise...... following pathologies such as brain injuries, brain tumours, and cerebral ischemia. As vasopressin and its G-protein-coupled receptor (V1(a)R) have been shown to affect the outcome of brain edema, we have investigated the regulatory interaction between AQP4 and V1(a)R by heterologous expression in Xenopus......)R may prove to be a potential therapeutic target in the prevention and treatment of brain edema....

Sangivamycin-Like Molecule 6 (SLM6) exhibits potent anti-multiple myeloma activity through inhibition of cyclin-dependent kinase-9 (CDK9)

Science.gov (United States)

Dolloff, Nathan G.; Allen, Joshua E.; Dicker, David T.; Aqui, Nicole; Vogl, Dan; Malysz, Jozef; Talamo, Giampaolo; El-Deiry, Wafik S.

2012-01-01

Despite significant treatment advances over the past decade, multiple myeloma (MM) remains largely incurable. In this study we found that MM cells were remarkably sensitive to the death-inducing effects of a new class of sangivamycin-like molecules (SLMs). A panel of structurally related SLMs selectively induced apoptosis in MM cells but not other tumor or non-malignant cell lines at sub-micromolar concentrations. SLM6 was the most active compound in vivo, where it was well-tolerated and significantly inhibited growth and induced apoptosis of MM tumors. We determined that the anti-MM activity of SLM6 was mediated by direct inhibition of cyclin-dependent kinase 9 (CDK9), which resulted in transcriptional repression of oncogenes that are known to drive MM progression (c-Maf, cyclin D1, and c-Myc). Furthermore, SLM6 demonstrated superior in vivo anti-MM activity over the CDK inhibitor flavopiridol, which is currently in clinical trials for MM. These findings demonstrate that SLM6 is a novel CDK9 inhibitor with promising preclinical activity as an anti-MM agent. PMID:22964485

Role of Aquaporin 0 in lens biomechanics

Energy Technology Data Exchange (ETDEWEB)

Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

2015-07-10

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

Role of Aquaporin 0 in lens biomechanics

International Nuclear Information System (INIS)

Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G.; Menon, Anil G.; Mathias, Richard T.; Varadaraj, Kulandaiappan

2015-01-01

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5 −/− ), AQP0 KO (heterozygous KO: AQP0 +/− ; homozygous KO: AQP0 −/− ; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0 +/− lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to

OPTIC NEURITIS IN NEUROMYELITIS OPTICA

Science.gov (United States)

Levin, Marc H.; Bennett, Jeffrey L.; Verkman, A.S.

2013-01-01

Neuromyelitis optica (NMO) is an autoimmune demyelinating disease associated with recurrent episodes of optic neuritis and transverse myelitis, often resulting in permanent blindness and/or paralysis. The discovery of autoantibodies (AQP4-IgG) that target aquaporin-4 (AQP4) has accelerated our understanding of the cellular mechanisms driving NMO pathogenesis. AQP4 is a bidirectional water channel expressed on the plasma membranes of astrocytes, retinal Müller cells, skeletal muscle, and some epithelial cells in kidney, lung and the gastrointestinal tract. AQP4 tetramers form regular supramolecular assemblies at the cell plasma membrane called orthogonal arrays of particles. The pathological features of NMO include perivascular deposition of immunoglobulin and activated complement, loss of astrocytic AQP4, inflammatory infiltration with granulocyte and macrophage accumulation, and demyelination with axon loss. Current evidence supports a causative role of AQP4-IgG in NMO, in which binding of AQP4-IgG to AQP4 orthogonal arrays on astrocytes initiates complement-dependent and antibody-dependent cell-mediated cytotoxicity and inflammation. Immunosuppression and plasma exchange are the mainstays of therapy for NMO optic neuritis. Novel therapeutics targeting specific steps in NMO pathogenesis are entering the development pipeline, including blockers of AQP4-IgG binding to AQP4 and inhibitors of granulocyte function. However, much work remains in understanding the unique susceptibility of the optic nerves in NMO, in developing animal models of NMO optic neuritis, and in improving therapies to preserve vision. PMID:23545439

Knockdown of HSPA9 induces TP53-dependent apoptosis in human hematopoietic progenitor cells.

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Tuoen Liu

Full Text Available Myelodysplastic syndromes (MDS are the most common adult myeloid blood cancers in the US. Patients have increased apoptosis in their bone marrow cells leading to low peripheral blood counts. The full complement of gene mutations that contribute to increased apoptosis in MDS remains unknown. Up to 25% of MDS patients harbor and acquired interstitial deletion on the long arm of chromosome 5 [del(5q], creating haploinsufficiency for a large set of genes including HSPA9. Knockdown of HSPA9 in primary human CD34+ hematopoietic progenitor cells significantly inhibits growth and increases apoptosis. We show here that HSPA9 knockdown is associated with increased TP53 expression and activity, resulting in increased expression of target genes BAX and p21. HSPA9 protein interacts with TP53 in CD34+ cells and knockdown of HSPA9 increases nuclear TP53 levels, providing a possible mechanism for regulation of TP53 by HSPA9 haploinsufficiency in hematopoietic cells. Concurrent knockdown of TP53 and HSPA9 rescued the increased apoptosis observed in CD34+ cells following knockdown of HSPA9. Reduction of HSPA9 below 50% results in severe inhibition of cell growth, suggesting that del(5q cells may be preferentially sensitive to further reductions of HSPA9 below 50%, thus providing a genetic vulnerability to del(5q cells. Treatment of bone marrow cells with MKT-077, an HSPA9 inhibitor, induced apoptosis in a higher percentage of cells from MDS patients with del(5q compared to non-del(5q MDS patients and normal donor cells. Collectively, these findings indicate that reduced levels of HSPA9 may contribute to TP53 activation and increased apoptosis observed in del(5q-associated MDS.

Adiabatic pressure dependence of the 2.7 and 1.9 micron water vapor bands

Science.gov (United States)

Mathai, C. V.; Walls, W. L.; Broersma, S.

1977-01-01

An acoustic excitation technique is used to determine the adiabatic pressure derivative of the spectral absorptance of the 2.7 and 1.9 micron water vapor bands, and the 3.5 micron HCl band. The dependence of this derivative on thermodynamic parameters such as temperature, concentration, and pressure is evaluated. A cross-flow water vapor system is used to measure spectral absorptance. Taking F as the ratio of nonrigid to rotor line strengths, it is found that an F factor correction is needed for the 2.7 micron band. The F factor for the 1.9 micron band is also determined. In the wings of each band a wavelength can be found where the concentration dependence is predominant. Farther out in the wings a local maximum occurs for the temperature derivative. It is suggested that the pressure derivative is significant in the core of the band.

Genome-Wide Identification and Expression Analyses of Aquaporin Gene Family during Development and Abiotic Stress in Banana

Science.gov (United States)

Hu, Wei; Hou, Xiaowan; Huang, Chao; Yan, Yan; Tie, Weiwei; Ding, Zehong; Wei, Yunxie; Liu, Juhua; Miao, Hongxia; Lu, Zhiwei; Li, Meiying; Xu, Biyu; Jin, Zhiqiang

2015-01-01

Aquaporins (AQPs) function to selectively control the flow of water and other small molecules through biological membranes, playing crucial roles in various biological processes. However, little information is available on the AQP gene family in bananas. In this study, we identified 47 banana AQP genes based on the banana genome sequence. Evolutionary analysis of AQPs from banana, Arabidopsis, poplar, and rice indicated that banana AQPs (MaAQPs) were clustered into four subfamilies. Conserved motif analysis showed that all banana AQPs contained the typical AQP-like or major intrinsic protein (MIP) domain. Gene structure analysis suggested the majority of MaAQPs had two to four introns with a highly specific number and length for each subfamily. Expression analysis of MaAQP genes during fruit development and postharvest ripening showed that some MaAQP genes exhibited high expression levels during these stages, indicating the involvement of MaAQP genes in banana fruit development and ripening. Additionally, some MaAQP genes showed strong induction after stress treatment and therefore, may represent potential candidates for improving banana resistance to abiotic stress. Taken together, this study identified some excellent tissue-specific, fruit development- and ripening-dependent, and abiotic stress-responsive candidate MaAQP genes, which could lay a solid foundation for genetic improvement of banana cultivars. PMID:26307965

CARD9-Dependent Neutrophil Recruitment Protects against Fungal Invasion of the Central Nervous System.

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Rebecca A Drummond

2015-12-01

Full Text Available Candida is the most common human fungal pathogen and causes systemic infections that require neutrophils for effective host defense. Humans deficient in the C-type lectin pathway adaptor protein CARD9 develop spontaneous fungal disease that targets the central nervous system (CNS. However, how CARD9 promotes protective antifungal immunity in the CNS remains unclear. Here, we show that a patient with CARD9 deficiency had impaired neutrophil accumulation and induction of neutrophil-recruiting CXC chemokines in the cerebrospinal fluid despite uncontrolled CNS Candida infection. We phenocopied the human susceptibility in Card9-/- mice, which develop uncontrolled brain candidiasis with diminished neutrophil accumulation. The induction of neutrophil-recruiting CXC chemokines is significantly impaired in infected Card9-/- brains, from both myeloid and resident glial cellular sources, whereas cell-intrinsic neutrophil chemotaxis is Card9-independent. Taken together, our data highlight the critical role of CARD9-dependent neutrophil trafficking into the CNS and provide novel insight into the CNS fungal susceptibility of CARD9-deficient humans.

ROCK inhibition stimulates SOX9/Smad3-dependent COL2A1 expression in inner meniscus cells.

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Furumatsu, Takayuki; Maehara, Ami; Ozaki, Toshifumi

2016-07-01

Proper functioning of the meniscus depends on the composition and organization of its fibrocartilaginous extracellular matrix. We previously demonstrated that the avascular inner meniscus has a more chondrocytic phenotype compared with the outer meniscus. Inhibition of the Rho family GTPase ROCK, the major regulator of the actin cytoskeleton, stimulates the chondrogenic transcription factor Sry-type HMG box (SOX) 9-dependent α1(II) collagen (COL2A1) expression in inner meniscus cells. However, the crosstalk between ROCK inhibition, SOX9, and other transcription modulators on COL2A1 upregulation remains unclear in meniscus cells. The aim of this study was to investigate the role of SOX9-related transcriptional complex on COL2A1 expression under the inhibition of ROCK in human meniscus cells. Human inner and outer meniscus cells were prepared from macroscopically intact lateral menisci. Cells were cultured in the presence or absence of ROCK inhibitor (ROCKi, Y27632). Gene expression, collagen synthesis, and nuclear translocation of SOX9 and Smad2/3 were analyzed. Treatment of ROCKi increased the ratio of type I/II collagen double positive cells derived from the inner meniscus. In real-time PCR analyses, expression of SOX9 and COL2A1 genes was stimulated by ROCKi treatment in inner meniscus cells. ROCKi treatment also induced nuclear translocation of SOX9 and phosphorylated Smad2/3 in immunohistological analyses. Complex formation between SOX9 and Smad3 was increased by ROCKi treatment in inner meniscus cells. Chromatin immunoprecipitation analyses revealed that association between SOX9/Smad3 transcriptional complex with the COL2A1 enhancer region was increased by ROCKi treatment. This study demonstrated that ROCK inhibition stimulated SOX9/Smad3-dependent COL2A1 expression through the immediate nuclear translocation of Smad3 in inner meniscus cells. Our results suggest that ROCK inhibition can stimulates type II collagen synthesis through the cooperative activation

Performance Characteristics of CA 19-9 Radioimmunoassay and Clinical Significance of Serum CA 19-9 Assay in Patients with Malignancy

International Nuclear Information System (INIS)

Kim, Sang Eun; Shong, Young Kee; Cho, Bo Youn; Kim, Noe Kyeong; Koh, Chang Soon; Lee, Mun Ho; Hong, Seong Woon; Hong, Kee Suk

1985-01-01

To evaluate the performance characteristics of CA 19-9 radioimmunoassay and the clinical significance of serum CA 19-9 assay in patients with malignancy, serum. CA 19-9 levels were measured by radioimmunoassay using monoclonal antibody in 135 normal controls, 81 patients with various untreated malignancy, 9 patients of postoperative colon cancer without recurrence and 20 patients with benign gastrointestinal diseases, who visited Seoul National University Hospital from June, 1984 to March, 1985. The results were as follows; 1) The CA 19-9 radioimmunoassay was simple to perform and can be completed in one work day. And the between-assay reproducibility and the assay recovery were both excellent. 2) The mean serum CA 19-9 level in 135 normal controls was 8.4±4.2 U/mL. Normal upper limit of serum CA 19-9 was defined as 21.0 U/mL. 4 out of 135 (3.0%) normal controls showed elevated CA 19-9 levels above the normal upper limit. 3) One out of 20 (5.0%) patients with benign gastrointestinal diseases showed elevated serum CA 19-9 level above the normal upper limit. 4) In 81 patients with various untreated malignancy, 41 patients (50.6%) showed elevated serum CA 19-9 levels. 66.7% of 18 patients with colorectal cancer, 100% of 2 patients with pancreatic cancer, 100% of 3 patients with common bile duct cancer, 47.1% of 17 patients with stomach cancer, 28.6% of 28 patients with hepatoma and 60.0% of 5 gastrointestinal tract cancers showed elevated serum CA 19-9 levels. 5) The sensitivities of serum CA 19-9 related to respectability in colorectal and stomach cancer were 33.3% in resectable colorectal cancer, 83.3% in unresectable colorectal cancer, 41.7% in resectable stomach cancer, 60.0% in unresectable stomach cancer respectively. 6) The sensitivity of serum CA 19-9 in 9 patients of postoperative colorectal cancer without recurrence were 33.3% and significantly decreased compared with that of untreated colorectal cancer, 66.7% (p<0.05). 7) In Patients with colorectal cancer

Determination of relative CMRO2 from CBF and BOLD changes: significant increase of oxygen consumption rate during visual stimulation

DEFF Research Database (Denmark)

Kim, S.G.; Rostrup, Egill; Larsson, H.B.

1999-01-01

signal changes were measured simultaneously using the flow-sensitive alternating inversion recovery (FAIR) technique. During hypercapnia established by an end-tidal CO2 increase of 1.46 kPa, CBF in the visual cortex increased by 47.3 +/- 17.3% (mean +/- SD; n = 9), and deltaR2* was -0.478 +/- 0.147 sec......The blood oxygenation level-dependent (BOLD) effect in functional magnetic resonance imaging depends on at least partial uncoupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) changes. By measuring CBF and BOLD simultaneously, the relative change in CMRO2 can...

[Proportion and significance of CD1d(hi)CD5⁺CD19⁺ regulatory B cell in peripheral blood of patients with neuromyelitis optica].

Science.gov (United States)

Yang, Fen; Huang, Dehui; Cheng, Chen; Wu, Weiping

2015-03-01

To detect the proportion of CD1d(hi)CD5⁺CD19⁺ regulatory B cells (Bregs) in peripheral blood of the patients with neuromyelitis optica (NMO), and explore whether CD1d(hi)CD5⁺CD19⁺ Bregs can play a role as a biomarker in the diagnosis of NMO versus multiple sclerosis (MS). Flow cytometry was performed to detect the proportion of CD1d(hi)CD5⁺CD19⁺ Bregs in peripheral blood from 44 cases of NMO, 38 cases of MS, and 30 healthy controls. The serum level of aquaporin-4 antibody (AQP4-Ab) of patients with NMO was detected by indirect immunofluorescence assay. The proportion of CD1d(hi)CD5⁺CD19⁺ Bregs in CD19⁺ B cells and lymphocytes was significantly lower in NMO group than in MS and control groups; however, there was no significant difference between MS group and control group. The proportion of CD1d(hi)CD5⁺CD19⁺ Bregs in CD19⁺ B cells and lymphocytes was lower in AQP4-Ab-positive NMO patients than in AQP4-Ab-negative NMO patients, and the difference was statistically significant. CD1d(hi)CD5⁺CD19⁺ Bregs may be a biomarker in the differential diagnosis of NMO versus MS.

Local time and cutoff rigidity dependences of storm time increase associated with geomagnetic storms

International Nuclear Information System (INIS)

Kudo, S.; Wada, M.; Tanskanen, P.; Kodama, M.

1987-01-01

The cosmic ray increases due to considerable depressions of cosmic ray cutoff rigidity during large geomagnetic storms are investigated. Data from a worldwide network of cosmic ray neutron monitors are analyzed for 17 geomagnetic storms which occurred in the quiet phase of the solar activity cycle during 1966-1978. As expected from the longitudinal asymmetry of the low-altitude geomagnetic field during large geomagnetic storms, a significant local time dependence of the increment in the cosmic ray during large geomagnetic storms, a significant local time dependence of the increment in the cosmic ray intensity is obtained. It is shown that the maximum phases of the local time dependence occur at around 1800 LT and that the amplitudes of the local time dependence are consistent with presently available theoretical estimates. The dependence of the increment on the cutoff rigidity is obtained for both the local time dependent part and the local time independent part of the storm time increase. The local time independent part, excluding the randomizing local time dependent part, shows a clear-cut dependence on cutoff rigidity which is consistent with theoretical estimates

Purification and functional characterization of nine human Aquaporins produced in Saccharomyces cerevisiae for the purpose of biophysical characterization

DEFF Research Database (Denmark)

Pedersen, Per Amstrup; Gourdon, Pontus Emanuel; Gotfryd, Kamil

2017-01-01

investigated the capacity of S. cerevisiae to deliver high yields of prime quality human AQPs, focusing on poorly characterized members including some previously shown to be difficult to isolate. Exploiting GFP labeled forms we comprehensively optimized production and purification procedures resulting...... in satisfactory yields of all nine AQP targets. We applied the obtained knowledge to successfully upscale purification of histidine tagged human AQP10 produced in large bioreactors. Glycosylation analysis revealed that AQP7 and 12 were O-glycosylated, AQP10 was N-glycosylated while the other AQPs were...... not glycosylated. We furthermore performed functional characterization and found that AQP 2, 6 and 8 allowed flux of water whereas AQP3, 7, 9, 10, 11 and 12 also facilitated a glycerol flux. In conclusion, our S. cerevisiae platform emerges as a powerful tool for isolation of functional, difficult-to-express human...

Cloning of aquaporin-1 of the blue crab, Callinectes sapidus: its expression during the larval development in hyposalinity.

Science.gov (United States)

Chung, J Sook; Maurer, Leah; Bratcher, Meagan; Pitula, Joseph S; Ogburn, Matthew B

2012-09-03

Ontogenetic variation in salinity adaptation has been noted for the blue crab, Callinectes sapidus, which uses the export strategy for larval development: females migrate from the estuaries to the coast to spawn, larvae develop in the ocean, and postlarvae (megalopae) colonize estuarine areas. We hypothesized that C. sapidus larvae may be stenohaline and have limited osmoregulatory capacity which compromises their ability to survive in lower salinity waters. We tested this hypothesis using hatchery-raised larvae that were traceable to specific life stages. In addition, we aimed to understand the possible involvement of AQP-1 in salinity adaptation during larval development and during exposure to hyposalinity. A full-length cDNA sequence of aquaporin (GenBank JQ970426) was isolated from the hypodermis of the blue crab, C. sapidus, using PCR with degenerate primers and 5' and 3' RACE. The open reading frame of CasAQP-1 consists of 238 amino acids containing six helical structures and two NPA motifs for the water pore. The expression pattern of CasAQP-1 was ubiquitous in cDNAs from all tissues examined, although higher in the hepatopancreas, thoracic ganglia, abdominal muscle, and hypodermis and lower in the antennal gland, heart, hemocytes, ovary, eyestalk, brain, hindgut, Y-organs, and gill. Callinectes larvae differed in their capacity to molt in hyposalinity, as those at earlier stages from Zoea (Z) 1 to Z4 had lower molting rates than those from Z5 onwards, as compared to controls kept in 30 ppt water. No difference was found in the survival of larvae held at 15 and 30 ppt. CasAQP-1 expression differed with ontogeny during larval development, with significantly higher expression at Z1-2, compared to other larval stages. The exposure to 15 ppt affected larval-stage dependent CasAQP-1 expression which was significantly higher in Z2- 6 stages than the other larval stages. We report the ontogenetic variation in CasAQP-1 expression during the larval development

Rab9-dependent retrograde transport and endosomal sorting of the endopeptidase furin

Science.gov (United States)

Chia, Pei Zhi Cheryl; Gasnereau, Isabelle; Lieu, Zi Zhao; Gleeson, Paul A.

2011-01-01

The endopeptidase furin and the trans-Golgi network protein TGN38 are membrane proteins that recycle between the TGN and plasma membrane. TGN38 is transported by a retromer-dependent pathway from early endosomes to the TGN, whereas the intracellular transport of furin is poorly defined. Here we have identified the itinerary and transport requirements of furin. Using internalisation assays, we show that furin transits the early and late endosomes en route to the TGN. The GTPase Rab9 and the TGN golgin GCC185, components of the late endosome-to-TGN pathway, were required for efficient TGN retrieval of furin. By contrast, TGN38 trafficking was independent of Rab9 and GCC185. To identify the sorting signals for the early endosome-to-TGN pathway, the trafficking of furin–TGN38 chimeras was investigated. The diversion of furin from the Rab9-dependent late-endosome-to-TGN pathway to the retromer-dependent early-endosome-to-TGN pathway required both the transmembrane domain and cytoplasmic tail of TGN38. We present evidence to suggest that the length of the transmembrane domain is a contributing factor in endosomal sorting. Overall, these data show that furin uses the Rab9-dependent pathway from late endosomes and that retrograde transport directly from early endosomes is dependent on both the transmembrane domain and the cytoplasmic tail. PMID:21693586

Glial molecular alterations with mouse brain development and aging: up-regulation of the Kir4.1 and aquaporin-4.

Science.gov (United States)

Gupta, Rajaneesh Kumar; Kanungo, Madhusudan

2013-02-01

Glial cells, besides participating as passive supporting matrix, are also proposed to be involved in the optimization of the interstitial space for synaptic transmission by tight control of ionic and water homeostasis. In adult mouse brain, inwardly rectifying K+ (Kir4.1) and aquaporin-4 (AQP4) channels localize to astroglial endfeets in contact with brain microvessels and glutamate synapses, optimizing clearance of extracellular K(+) and water from the synaptic layers. However, it is still unclear whether there is an age-dependent difference in the expressions of Kir4.1 and AQP4 channels specifically during postnatal development and aging when various marked changes occur in brain and if these changes region specific. RT-PCR and immunoblotting was conducted to compare the relative expression of Kir4.1 and AQP4 mRNA and protein in the early and mature postnatal (0-, 15-, 45-day), adult (20-week), and old age (70-week) mice cerebral and cerebellar cortices. Expressions of Kir4.1 and AQP4 mRNA and protein are very low at 0-day. A pronounced and continuous increase was observed by mature postnatal ages (15-, 45-days). However, in the 70-week-old mice, expressions are significantly up-regulated as compared to 20-week-old mice. Both genes follow the same age-related pattern in both cerebral and cerebellar cortices. The time course and expression pattern suggests that Kir4.1 and AQP4 channels may play an important role in brain K(+) and water homeostasis in early postnatal weeks after birth and during aging.

Role of Aquaporin Water Channels in Airway Fluid Transport, Humidification, and Surface Liquid Hydration

Science.gov (United States)

Song, Yuanlin; Jayaraman, Sujatha; Yang, Baoxue; Matthay, Michael A.; Verkman, A.S.

2001-01-01

Several aquaporin-type water channels are expressed in mammalian airways and lung: AQP1 in microvascular endothelia, AQP3 in upper airway epithelia, AQP4 in upper and lower airway epithelia, and AQP5 in alveolar epithelia. Novel quantitative methods were developed to compare airway fluid transport–related functions in wild-type mice and knockout mice deficient in these aquaporins. Lower airway humidification, measured from the moisture content of expired air during mechanical ventilation with dry air through a tracheotomy, was 54–56% efficient in wild-type mice, and reduced by only 3–4% in AQP1/AQP5 or AQP3/AQP4 double knockout mice. Upper airway humidification, measured from the moisture gained by dry air passed through the upper airways in mice breathing through a tracheotomy, decreased from 91 to 50% with increasing ventilation from 20 to 220 ml/min, and reduced by 3–5% in AQP3/AQP4 knockout mice. The depth and salt concentration of the airway surface liquid in trachea was measured in vivo using fluorescent probes and confocal and ratio imaging microscopy. Airway surface liquid depth was 45 ± 5 μm and [Na+] was 115 ± 4 mM in wild-type mice, and not significantly different in AQP3/AQP4 knockout mice. Osmotic water permeability in upper airways, measured by an in vivo instillation/sample method, was reduced by ∼40% by AQP3/AQP4 deletion. In doing these measurements, we discovered a novel amiloride-sensitive isosmolar fluid absorption process in upper airways (13% in 5 min) that was not affected by aquaporin deletion. These results establish the fluid transporting properties of mouse airways, and indicate that aquaporins play at most a minor role in airway humidification, ASL hydration, and isosmolar fluid absorption. PMID:11382807

Tetraethylammonium block of water flux in Aquaporin-1 channels expressed in kidney thin limbs of Henle's loop and a kidney-derived cell line.

Directory of Open Access Journals (Sweden)

Pannabecker Thomas L

2002-03-01

Full Text Available Abstract Background Aquaporin-1 (AQP1 channels are constitutively active water channels that allow rapid transmembrane osmotic water flux, and also serve as cyclic-GMP-gated ion channels. Tetraethylammonium chloride (TEA; 0.05 to 10 mM was shown previously to inhibit the osmotic water permeability of human AQP1 channels expressed in Xenopus oocytes. The purpose of the present study was to determine if TEA blocks osmotic water flux of native AQP1 channels in kidney, and recombinant AQP1 channels expressed in a kidney derived MDCK cell line. We also demonstrate that TEA does not inhibit the cGMP-dependent ionic conductance of AQP1 expressed in oocytes, supporting the idea that water and ion fluxes involve pharmacologically distinct pathways in the AQP1 tetrameric complex. Results TEA blocked water permeability of AQP1 channels in kidney and kidney-derived cells, demonstrating this effect is not limited to the oocyte expression system. Equivalent inhibition is seen in MDCK cells with viral-mediated AQP1 expression, and in rat renal descending thin limbs of Henle's loops which abundantly express native AQP1, but not in ascending thin limbs which do not express AQP1. External TEA (10 mM does not block the cGMP-dependent AQP1 ionic conductance, measured by two-electrode voltage clamp after pre-incubation of oocytes in 8Br-cGMP (10–50 mM or during application of the nitric oxide donor, sodium nitroprusside (2–4 mM. Conclusions TEA selectively inhibits osmotic water permeability through native and heterologously expressed AQP1 channels. The pathways for water and ions in AQP1 differ in pharmacological sensitivity to TEA, and are consistent with the idea of independent solute pathways within the channel structure. The results confirm the usefulness of TEA as a pharmacological tool for the analysis of AQP1 function.

Aquaporin-3 in Cancer.

Science.gov (United States)

Marlar, Saw; Jensen, Helene H; Login, Frédéric H; Nejsum, Lene N

2017-10-07

Increasing evidence suggests that the water/glycerol channel aquaporin-3 (AQP3) plays a pivotal role in cancer metastasis. AQP3 knockout mice were resistant to skin tumor formation and overexpression correlated with metastasis and poor prognosis in patients with breast or gastric cancer. In cultured cancer cells, increased AQP3 expression stimulated several intracellular signaling pathways and resulted in increased cell proliferation, migration, and invasion as well as aggravation of epithelial-to-mesenchymal transition. Besides AQP facilitated water transport at the leading edge of migrating cells, AQP3 signaling mechanisms are beginning to be unraveled. Here, we give a thorough review of current knowledge regarding AQP3 expression in cancer and how AQP3 contributes to cancer progression via signaling that modulates cellular mechanisms. This review article will expand our understanding of the known pathophysiological findings regarding AQP3 in cancer.

Aquaporin-4 autoantibodies in neuromyelitis optica spectrum disorders: comparison between tissue-based and cell-based indirect immunofluorescence assays

Directory of Open Access Journals (Sweden)

Chan Koon H

2010-09-01

Full Text Available Abstract Background Neuromyelitis optica spectrum disorders (NMOSD are severe central nervous system inflammatory demyelinating disorders (CNS IDD characterized by monophasic or relapsing, longitudinally extensive transverse myelitis (LETM and/or optic neuritis (ON. A significant proportion of NMOSD patients are seropositive for aquaporin-4 (AQP4 autoantibodies. We compared the AQP4 autoantibody detection rates of tissue-based indirect immunofluorescence assay (IIFA and cell-based IIFA. Methods Serum of Chinese CNS IDD patients were assayed for AQP4 autoantibodies by tissue-based IIFA using monkey cerebellum and cell-based IIFA using transfected HEK293 cells which express human AQP4 on their cell membranes. Results In total, 128 CNS IDD patients were studied. We found that 78% of NMO patients were seropositive for AQP4 autoantibodies by cell-based IIFA versus 61% by tissue-based IFA (p = 0.250, 75% of patients having relapsing myelitis (RM with LETM were seropositive by cell-based IIFA versus 50% by tissue-based IIFA (p = 0.250, and 33% of relapsing ON patients were seropositive by cell-based IIFA versus 22% by tissue-based IIFA (p = 1.000; however the differences were not statistically significant. All patients seropositive by tissue-based IIFA were also seropositive for AQP4 autoantibodies by cell-based IIFA. Among 29 NMOSD patients seropositive for AQP4 autoantibodies by cell-based IIFA, 20 (69% were seropositive by tissue-based IIFA. The 9 patients seropositive by cell-based IIFA while seronegative by tissue-based IIFA had NMO (3, RM with LETM (3, a single attack of LETM (1, relapsing ON (1 and a single ON attack (1. Among 23 NMO or RM patients seropositive for AQP4 autoantibodies by cell-based IIFA, comparison between those seropositive (n = 17 and seronegative (n = 6 by tissue-based IIFA revealed no differences in clinical and neuroradiological characteristics between the two groups. Conclusion Cell-based IIFA is slightly more sensitive

Ectopic expression of aquaporin-5 in noncancerous epithelial MDCK cells changes cellular morphology and actin fiber formation without inducing epithelial-to-mesenchymal transition.

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Jensen, Helene H; Holst, Mikkel R; Login, Frédéric H; Morgen, Jeanette J; Nejsum, Lene N

2018-06-01

Aquaporin-5 (AQP5) is a plasma membrane water channel mainly expressed in secretory glands. Increased expression of AQP5 is observed in multiple cancers, including breast cancer, where high expression correlates with the degree of metastasis and poor prognosis. Moreover, studies in cancer cells have suggested that AQP5 activates Ras signaling, drives morphological changes, and in particular increased invasiveness. To design intervention strategies, it is of utmost importance to characterize and dissect the cell biological changes induced by altered AQP5 expression. To isolate the effect of AQP5 overexpression from the cancer background, AQP5 was overexpressed in normal epithelial MDCK cells which have no endogenous AQP5 expression. AQP5 overexpression promoted actin stress fiber formation and lamellipodia dynamics. Moreover, AQP5 decreased cell circularity. Phosphorylation of AQP5 on serine 156 in the second intracellular loop has been shown to activate the Ras pathway. When serine 156 was mutated to alanine to mimic the nonphosphorylated state, the decrease in cell circularity was reversed, indicating that the AQP5-Ras axis is involved in the effect on cell shape. Interestingly, the cellular changes mediated by AQP5 were not associated with induction of epithelial-to-mesenchymal transition. Thus, AQP5 may contribute to cancer by altering cellular morphology and actin organization, which increase the metastatic potential.

Significance in the increase of women psychiatrists in Korea.

Science.gov (United States)

Kim, Ha Kyoung; Kim, Soo In

2008-01-01

The number of female doctors has increased in Korea; 18.9% (13,083) of the total medical doctors registered (69,097) were women in 2006, compared to 13.6% (2,216) in 1975. The proportion of female doctors will jump up by 2010 considering that nearly 40% of the medical students are women as of today. This trend has had strong influence on the field of psychiatry; the percentage of women psychiatrists rose from 1.6 (6)% to 18% (453), from 1975 to 2006 and now women residents comprise 39% (206) of all. This is not only a reflection of a social phenomenon of the increase in professional women but also attributed to some specific characteristics of the psychiatry. Psychiatric practice may come more natural to women. While clinical activities of women psychiatrists are expanding, there are few women leaders and much less women are involving in academic activities in this field as yet. Though there is less sexual discrimination in the field of psychiatry, women psychiatrists are still having a lot of difficulties in balancing work and family matters. Many women psychiatrists also report they've ever felt an implied discrimination in their careers. In this study, we are to identify the characteristics of women psychiatrists and to explore the significance of the increase in women psychiatrists in Korea and the situation in which they are.

Regulation of the Water Channel Aquaporin-2 via 14-3-3θ and -ζ

DEFF Research Database (Denmark)

Moeller, Hanne B; Slengerik-Hansen, Joachim; Aroankins, Takwa

2016-01-01

The 14-3-3 family of proteins are multifunctional proteins that interact with many of their cellular targets in a phosphorylation-dependent manner. Here, we determined that 14-3-3 proteins interact with phosphorylated forms of the water channel aquaporin-2 (AQP2) and modulate its function. With t...... levels. In conclusion, this study demonstrates phosphorylation-dependent interactions of AQP2 with 14-3-3 θ and ζ. These interactions play divergent roles in modulating AQP2 trafficking, phosphorylation, ubiquitylation and degradation....

Increased glucose dependence in resting, iron-deficient rats

International Nuclear Information System (INIS)

Brooks, G.A.; Henderson, S.A.; Dallman, P.R.

1987-01-01

Rates of blood glucose and lactate turnover were assessed in resting iron-deficient and iron-sufficient (control) rats to test the hypothesis that dependence on glucose metabolism is increased in iron deficiency. Male Sprague-Dawley rats, 21 days old, were fed a diet containing either 6 mg iron/kg feed (iron-deficient group) or 50 mg iron/kg feed (iron-sufficient group) for 3-4 wk. The iron-deficient group became anemic, with hemoglobin levels of 6.4 ± 0.2 compared with 13.8 ± 0.3 g/dl for controls. Rats received a 90-min primed continuous infusion of D-[6- 3 H]glucose and sodium L-[U- 14 C]lactate via a jugular catheter. Serial samples were taken from a carotid catheter for concentration and specific activity determinations. Iron-deficient rats had significantly higher blood glucose and lactate concentrations than controls. The iron-deficient group had a significantly higher glucose turnover rate than the control group. Significantly more metabolite recycling in iron-deficient rats was indicated by greater incorporation of 14 C into blood glucose. Assuming a carbon crossover correction factor of 2, half of blood glucose arose from lactate in deficient animals. By comparison, only 25% of glucose arose from lactate in controls. Lack of a difference in lactate turnover rates between deficient rats and controls was attributed to 14 C recycling. The results indicate a greater dependence on glucose metabolism in iron-deficient rats

Human umbilical cord mesenchymal stem cells increase interleukin-9 production of CD4+ T cells

Science.gov (United States)

Yang, Zhou Xin; Chi, Ying; Ji, Yue Ru; Wang, You Wei; Zhang, Jing; Luo, Wei Feng; Li, Li Na; Hu, Cai Dong; Zhuo, Guang Sheng; Wang, Li Fang; Han, Zhi-Bo; Han, Zhong Chao

2017-01-01

Mesenchymal stem cells (MSC) are able to differentiate into cells of multiple lineage, and additionally act to modulate the immune response. Interleukin (IL)-9 is primarily produced by cluster of differentiation (CD)4+ T cells to regulate the immune response. The present study aimed to investigate the effect of human umbilical cord derived-MSC (UC-MSC) on IL-9 production of human CD4+ T cells. It was demonstrated that the addition of UC-MSC to the culture of CD4+ T cells significantly enhanced IL-9 production by CD4+ T cells. Transwell experiments suggested that UC-MSC promotion of IL-9 production by CD4+ T cells was dependent on cell-cell contact. Upregulated expression of CD106 was observed in UC-MSC co-cultured with CD4+ T cells, and the addition of a blocking antibody of CD106 significantly impaired the ability of UC-MSC to promote IL-9 production by CD4+ T cells. Therefore, the results of the present study demonstrated that UC-MSC promoted the generation of IL-9 producing cells, which may be mediated, in part by CD106. The findings may act to expand understanding and knowledge of the immune modulatory role of UC-MSC. PMID:29042945

Recombinant IgG1 Fc hexamers block cytotoxicity and pathological changes in experimental in vitro and rat models of neuromyelitis optica.

Science.gov (United States)

Tradtrantip, Lukmanee; Felix, Christian M; Spirig, Rolf; Morelli, Adriana Baz; Verkman, A S

2018-05-01

Intravenous human immunoglobulin G (IVIG) may have therapeutic benefit in neuromyelitis optica spectrum disorders (herein called NMO), in part because of the anti-inflammatory properties of the IgG Fc region. Here, we evaluated recombinant Fc hexamers consisting of the IgM μ-tailpiece fused with the Fc region of human IgG1. In vitro, the Fc hexamers prevented cytotoxicity in aquaporin-4 (AQP4) expressing cells and in rat spinal cord slice cultures exposed to NMO anti-AQP4 autoantibody (AQP4-IgG) and complement, with >500-fold greater potency than IVIG or monomeric Fc fragments. Fc hexamers at low concentration also prevented antibody-dependent cellular cytotoxicity produced by AQP4-IgG and natural killer cells. Serum from rats administered a single intravenous dose of Fc hexamers at 50 mg/kg taken at 8 h did not produce complement-dependent cytotoxicity when added to AQP4-IgG-treated AQP4-expressing cell cultures. In an experimental rat model of NMO produced by intracerebral injection of AQP4-IgG, Fc hexamers at 50 mg/kg administered before and at 12 h after AQP4-IgG fully prevented astrocyte injury, complement activation, inflammation and demyelination. These results support the potential therapeutic utility of recombinant IgG1 Fc hexamers in AQP4-IgG seropositive NMO. Copyright © 2018 Elsevier Ltd. All rights reserved.

Brain Aquaporin-4 in Experimental Acute Liver Failure

Science.gov (United States)

Rama Rao, Kakulavarapu V.; Jayakumar, Arumugam R.; Tong, Xiaoying; Curtis, Kevin M.; Norenberg, Michael D.

2016-01-01

Intracranial hypertension due to brain edema and associated astrocyte swelling is a potentially lethal complication of acute liver failure (ALF). Mechanisms of edema formation are not well understood but elevated levels of blood and brain ammonia and its byproduct glutamine have been implicated in this process. We examined mRNA and protein expression of the water channel protein aquaporin-4 (AQP4) in cerebral cortex in a rat model of ALF induced by the hepatotoxin thioacetamide. Rats with ALF showed increased AQP4 protein in the plasma membrane (PM). Total tissue levels of AQP4 protein and mRNA levels were not altered indicating that increased AQP4 is not transcriptionally mediated but is likely due to a conformational change in the protein, i.e. a more stable anchoring of AQP4 to the PM and/or interference with its degradation. By immunohistochemistry there was an increase in AQP4 immunoreactivity in the PM of perivascular astrocytes in ALF. Rats with ALF showed increased levels of α-syntrophin, a protein involved in the anchoring of AQP4 to perivascular astrocytic end-feet. Increased AQP4 and α-syntrophin levels were inhibited by L-histidine, an inhibitor of glutamine transport into mitochondria, suggesting a role for glutamine in the increase of PM levels of AQP4. These results indicate that increased AQP4 PM levels in perivascular astrocytic end-feet are likely critical to the development of brain edema in ALF. PMID:20720509

Gas revenue increasingly significant

International Nuclear Information System (INIS)

Megill, R.E.

1991-01-01

This paper briefly describes the wellhead prices of natural gas compared to crude oil over the past 70 years. Although natural gas prices have never reached price parity with crude oil, the relative value of a gas BTU has been increasing. It is one of the reasons that the total amount of money coming from natural gas wells is becoming more significant. From 1920 to 1955 the revenue at the wellhead for natural gas was only about 10% of the money received by producers. Most of the money needed for exploration, development, and production came from crude oil. At present, however, over 40% of the money from the upstream portion of the petroleum industry is from natural gas. As a result, in a few short years natural gas may become 50% of the money revenues generated from wellhead production facilities

The psychosis-like effects of Δ(9)-tetrahydrocannabinol are associated with increased cortical noise in healthy humans.

Science.gov (United States)

Cortes-Briones, Jose A; Cahill, John D; Skosnik, Patrick D; Mathalon, Daniel H; Williams, Ashley; Sewell, R Andrew; Roach, Brian J; Ford, Judith M; Ranganathan, Mohini; D'Souza, Deepak Cyril

2015-12-01

Drugs that induce psychosis may do so by increasing the level of task-irrelevant random neural activity or neural noise. Increased levels of neural noise have been demonstrated in psychotic disorders. We tested the hypothesis that neural noise could also be involved in the psychotomimetic effects of delta-9-tetrahydrocannabinol (Δ(9)-THC), the principal active constituent of cannabis. Neural noise was indexed by measuring the level of randomness in the electroencephalogram during the prestimulus baseline period of an oddball task using Lempel-Ziv complexity, a nonlinear measure of signal randomness. The acute, dose-related effects of Δ(9)-THC on Lempel-Ziv complexity and signal power were studied in humans (n = 24) who completed 3 test days during which they received intravenous Δ(9)-THC (placebo, .015 and .03 mg/kg) in a double-blind, randomized, crossover, and counterbalanced design. Δ(9)-THC increased neural noise in a dose-related manner. Furthermore, there was a strong positive relationship between neural noise and the psychosis-like positive and disorganization symptoms induced by Δ(9)-THC, which was independent of total signal power. Instead, there was no relationship between noise and negative-like symptoms. In addition, Δ(9)-THC reduced total signal power during both active drug conditions compared with placebo, but no relationship was detected between signal power and psychosis-like symptoms. At doses that produced psychosis-like effects, Δ(9)-THC increased neural noise in humans in a dose-dependent manner. Furthermore, increases in neural noise were related with increases in Δ(9)-THC-induced psychosis-like symptoms but not negative-like symptoms. These findings suggest that increases in neural noise may contribute to the psychotomimetic effects of Δ(9)-THC. Published by Elsevier Inc.

Emerging roles of aquaporins in relation to the physiology of blood-feeding arthropods.

Science.gov (United States)

Benoit, Joshua B; Hansen, Immo A; Szuter, Elise M; Drake, Lisa L; Burnett, Denielle L; Attardo, Geoffrey M

2014-10-01

Aquaporins (AQPs) are proteins that span plasma membranes allowing the movement of water and small solutes into or out of cells. The type, expression levels and activity of AQPs play a major role in the relative permeability of each cell to water or other solutes. Research on arthropod AQPs has expanded in the last 10 years due to the completion of several arthropod genome projects and the increased availability of genetic information accessible through other resources such as de novo transcriptome assemblies. In particular, there has been significant advancement in elucidating the roles that AQPs serve in relation to the physiology of blood-feeding arthropods of medical importance. The focus of this review is upon the significance of AQPs in relation to hematophagy in arthropods. This will be accomplished via a narrative describing AQP functions during the life history of hematophagic arthropods that includes the following critical phases: (1) Saliva production necessary to blood feeding, (2) Intake and excretion of water during blood digestion, (3) Reproduction and egg development and (4) Off-host environmental stress tolerance. The concentration on these phases will highlight known vulnerabilities in the biology of hematophagic arthropods that could be used to develop novel control strategies as well as research topics that have yet to be examined.

Expression of aquaporin8 in human astrocytomas: Correlation with pathologic grade

International Nuclear Information System (INIS)

Zhu, Shu-juan; Wang, Ke-jian; Gan, Sheng-wei; Xu, Jin; Xu, Shi-ye; Sun, Shan-quan

2013-01-01

Highlights: •AQP8 is mainly distributed in the cytoplasm of human astrocytoma cells. •AQP8 over-expressed in human astrocytomas, especially glioblastoma. •The up-regulation of AQP8 is related to the pathological grade of human astrocytomas. •AQP8 may contribute to the growth and proliferation of astrocytomas. -- Abstract: Aquaporin8 (AQP8), a member of the aquaporin (AQP) protein family, is weakly distributed in mammalian brains. Previous studies on AQP8 have focused mainly on the digestive and the reproductive systems. AQP8 has a pivotal role in keeping the fluid and electrolyte balance. In this study, we investigated the expression changes of AQP8 in 75 cases of human brain astrocytic tumors using immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction. The results demonstrated that AQP8 was mainly distributed in the cytoplasm of astrocytoma cells. The expression levels and immunoreactive score of AQP8 protein and mRNA increased in low-grade astrocytomas, and further increased in high-grade astrocytomas, especially in glioblastoma. Therefore, AQP8 may contribute to the proliferation of astrocytomas, and may be a biomarker and candidate therapy target for patients with astrocytomas

Expression of aquaporin8 in human astrocytomas: Correlation with pathologic grade

Energy Technology Data Exchange (ETDEWEB)

Zhu, Shu-juan; Wang, Ke-jian; Gan, Sheng-wei; Xu, Jin; Xu, Shi-ye; Sun, Shan-quan, E-mail: sunsq2151@cqmu.edu.cn

2013-10-11

Highlights: •AQP8 is mainly distributed in the cytoplasm of human astrocytoma cells. •AQP8 over-expressed in human astrocytomas, especially glioblastoma. •The up-regulation of AQP8 is related to the pathological grade of human astrocytomas. •AQP8 may contribute to the growth and proliferation of astrocytomas. -- Abstract: Aquaporin8 (AQP8), a member of the aquaporin (AQP) protein family, is weakly distributed in mammalian brains. Previous studies on AQP8 have focused mainly on the digestive and the reproductive systems. AQP8 has a pivotal role in keeping the fluid and electrolyte balance. In this study, we investigated the expression changes of AQP8 in 75 cases of human brain astrocytic tumors using immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction. The results demonstrated that AQP8 was mainly distributed in the cytoplasm of astrocytoma cells. The expression levels and immunoreactive score of AQP8 protein and mRNA increased in low-grade astrocytomas, and further increased in high-grade astrocytomas, especially in glioblastoma. Therefore, AQP8 may contribute to the proliferation of astrocytomas, and may be a biomarker and candidate therapy target for patients with astrocytomas.

Up-regulation of Store-operated Ca2+ Entry and Nuclear Factor of Activated T Cells Promote the Acinar Phenotype of the Primary Human Salivary Gland Cells*

Science.gov (United States)

Jang, Shyh-Ing; Ong, Hwei Ling; Liu, Xibao; Alevizos, Ilias; Ambudkar, Indu S.

2016-01-01

The signaling pathways involved in the generation and maintenance of exocrine gland acinar cells have not yet been established. Primary human salivary gland epithelial cells, derived from salivary gland biopsies, acquired an acinar-like phenotype when the [Ca2+] in the serum-free medium (keratinocyte growth medium, KGM) was increased from 0.05 mm (KGM-L) to 1.2 mm (KGM-H). Here we examined the mechanism underlying this Ca2+-dependent generation of the acinar cell phenotype. Compared with cells in KGM-L, those in KGM-H display enhancement of Orai1, STIM1, STIM2, and nuclear factor of activated T cells 1 (NFAT1) expression together with an increase in store-operated Ca2+ entry (SOCE), SOCE-dependent nuclear translocation of pGFP-NFAT1, and NFAT-dependent but not NFκB-dependent gene expression. Importantly, AQP5, an acinar-specific protein critical for function, is up-regulated in KGM-H via SOCE/NFAT-dependent gene expression. We identified critical NFAT binding motifs in the AQP5 promoter that are involved in Ca2+-dependent up-regulation of AQP5. These important findings reveal that the Ca2+-induced switch of salivary epithelial cells to an acinar-like phenotype involves remodeling of SOCE and NFAT signaling, which together control the expression of proteins critically relevant for acinar cell function. Our data provide a novel strategy for generating and maintaining acinar cells in culture. PMID:26903518

Increased minimal vascular resistance and arteriolar hyalinosis in skin on the leg in insulin-dependent diabetic patients

DEFF Research Database (Denmark)

Kastrup, J; Nørgaard, T; Parving, H H

1987-01-01

Minimal vascular resistance (MVR) was determined in a paralysed cutaneous vascular bed at the dorsum of the foot in diabetic patients. Twelve long-term insulin-dependent diabetic (IDDM) patients with and nine short-term IDDM patients without nephropathy and retinopathy and eight control subjects......-wise increases of external counter pressure. The MVR was calculated from the reciprocal of the slope of the relationship between blood flow and applied pressure. The MVR was significantly increased in diabetic patients with (mean: 9.3 mmHg ml-1.100 g.min) and without nephropathy and retinopathy (8.5 mmHg ml-1.......100 g.min) compared with non-diabetic subjects (5.2 mmHg ml-1.100 g.min) (p less than 0.001 and p less than 0.005, respectively). Diabetic microangiopathy (increased hyalinosis of the basement membranes in the terminal arterioles) was found in skin biopsies in nine of the 12 long-term IDDM patients...

Delayed wound healing in aged skin rat models after thermal injury is associated with an increased MMP-9, K6 and CD44 expression.

Science.gov (United States)

Simonetti, Oriana; Oriana, Simonetti; Lucarini, Guendalina; Guendalina, Lucarini; Cirioni, Oscar; Oscar, Cirioni; Zizzi, Antonio; Antonio, Zizzi; Orlando, Fiorenza; Fiorenza, Orlando; Provinciali, Mauro; Mauro, Provinciali; Di Primio, Roberto; Roberto, Di Primio; Giacometti, Andrea; Andrea, Giacometti; Offidani, Annamaria; Annamaria, Offidani

2013-06-01

Age-related differences in wound healing have been documented but little is known about the wound healing mechanism after burns. Our aim was to compare histological features and immunohistochemical expression of matrix metalloproteinase-9 (MMP-9), collagen IV, K6 and CD44 in the burn wound healing process in aged and young rats. Following burns the appearance of the wound bed in aged rats had progressed but slowly, resulting in a delayed healing process compared to the young rats. At 21 days after injury, epithelial K6, MMP-9 and CD44 expression was significantly increased in aged rats with respect to young rats; moreover, in the aged rat group we observed a not fully reconstituted basement membrane. K6, MMP-9 and CD44 expression was significantly increased in wounded skin compared to unwounded skin both in young and aged rats. We hypothesise that delayed burn skin wound healing process in the aged rats may represent an age dependent response to injury where K6, MMP-9 and CD44 play a key role. It is therefore possible to suggest that these factors contribute to the delayed wound healing in aged skin and that modulation could lead to a better and faster recovery of skin damage in elderly. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Distribution of aquaporins in the nasal passage of Octodon degus, a South-American desert rodent and its implications for water conservation Distribución de acuaporinas en los pasajes nasales de Octodon degus, un roedor de ambientes desérticos sudamericanos: implicaciones en la conservación de agua

Directory of Open Access Journals (Sweden)

PEDRO GALLARDO

2008-03-01

Full Text Available Rodents from arid and semiarid environments live under conditions where the spatial and temporal availability of water is limited. Octodon degus is a South-American desert-dwelling rodent inhabiting arid and semiarid habitats of central and northern Chile. Its survival depends on morphological, physiological and behavioral adaptations that allow water conservation. This rodent has a high urine concentrating ability, high capacity of fecal dehydration and low evaporative water loss, related to the ability of the nasal passages to condense water from the exhaled air; this water must be absorbed in order to avoid its accumulation in the nasal passages and potential loss through the nostrils. We hypothesize that aquaporins (AQPs might be present in the nasal mucosa; therefore, we studied the distribution of AQP-1, AQP-2, AQP-3 and AQP-4 through immunocytochemistry. Intense AQP-1 labeling was observed throughout the subepithelial vascular network; no AQP-1 immunoreactivity was detected in olfactory and non-olfactory epithelial cells. No signal was detected for AQP-2 and 4. AQP-3 distribution was restricted to the surface non-olfactory epithelial cells lining the turbinates in narrow passages and blind spaces. Therefore, AQP-1 and AQP-3 coincided at the level of the turbinates, although in different cell types which suggest a pathway for water removal from the nasal surface first through AQP-3 in non-olfactory epithelial cells and then into the capillary lumen through AQP-1Los roedores de ambientes áridos y semiáridos viven bajo una disponibilidad limitada de agua tanto espacial como temporal. Octodon degus es un roedor sudamericano que habita ambientes áridos y semiáridos del norte y zona central de Chile. Su supervivencia depende de adaptaciones morfológicas, fisiológicas y conductuales que permiten optimizar la conservación de agua. Este tiene una alta capacidad de concentración urinaria y de deshidratación de la fecas además de una baja

Phenotypic flexibility at the molecular and organismal level allows desert-dwelling rodents to cope with seasonal water availability.

Science.gov (United States)

Gallardo, Pedro A; Cortes, Arturo; Bozinovic, Francisco

2005-01-01

We examined the phenotypic flexibility of field urine osmolality (Uosm) in response to seasonal rainfall and the experimental expression of renal aquaporins (AQPs) in the leaf-eared mouse Phyllotis darwini, a South American desert-dwelling rodent, through an integrative study at both the cellular and the organismal level. Field Uosm was higher in summer than in winter. Fall and winter Uosm were not significantly different. During a rainy year, winter Uosm was 2,140 +/- 82.3 mOsm kg(-1); the corresponding value in a dry year was 2,569 +/- 61.3 mOsm kg(-1). During the summer, the mean Uosm in a rainy year was 3,321 +/- 71.5 mOsm kg(-1), and in a dry year it was 3,604 +/- 107.2 mOsm kg(-1). The distribution of AQP-2, AQP-3, and AQP-4 was similar to that described for mouse and rat kidneys and confined to principal cells in cortex and inner medullary collecting-duct cells. AQP-4 immunoreactivity was unaltered by the state of water balance. Relative to water loading, dehydration induced an increase in AQP-2 immunoreactivity and protein abundance. Although more discrete, AQP-3 immunolabeling was also increased by dehydration. We now reveal how the integration of flexible renal mechanisms acting at the cellular and organismal level allow a small desert-dwelling mammal to cope with seasonal and yearly (El Nino) water availability in its semiarid habitat.

Unique and analogous functions of aquaporin O for fiber cell architecture and ocular lens transparency

Energy Technology Data Exchange (ETDEWEB)

Kumari, S.S.; Eswaramoorthy, S.; Mathias, R. T.; Varadaraj, K.

2011-09-01

Aquaporin (AQP) 1 and AQP0 water channels are expressed in lens epithelial and fiber cells, respectively, facilitating fluid circulation for nourishing the avascular lens to maintain transparency. Even though AQP0 water permeability is 40-fold less than AQP1, AQP0 is selectively expressed in the fibers. Delimited AQP0 fiber expression is attributed to a unique structural role as an adhesion protein. To validate this notion, we determined if wild type (WT) lens ultrastructure and fibercell adhesion are different in AQP0{sup -/-}, and TgAQP1{sup +/+}/AQP0{sup -/-} mice that transgenically express AQP1 (TgAQP1) in fibercells without AQP0 (AQP0{sup -/-}). In WT, lenses were transparent with 'Y' sutures. Fibers contained opposite end curvature, lateral interdigitations, hexagonal shape, and were arranged as concentric growth shells. AQP0{sup -/-}lenses were cataractous, lacked 'Y' sutures, ordered packing and well-defined lateral interdigitations. TgAQP1{sup +/+}/AQP0{sup -/-} lenses showed improvement in transparency and lateral interdigitations in the outer cortex while inner cortex and nuclear fibers were severely disintegrated. Transmission electron micrographs exhibited tightly packed fibercells in WT whereas AQP0{sup -/-} and TgAQP1{sup +/+}/AQP0{sup -/-}lenses had wide extracellular spaces. Fibers were easily separable by teasing in AQP0{sup -/-} and TgAQP1{sup +/+}/AQP0{sup -/-}lenses compared to WT. Our data suggest that the increased water permeability through AQP1 does not compensate for loss of AQP0 expression in TgAQP1{sup +/+}/AQP0{sup -/-} mice. Fibercell AQP0 expression is required to maintain their organization, which is a requisite for lenstransparency. AQP0 appears necessary for cell-to-cell adhesion and thereby to minimize light scattering since in the AQP0{sup -/-} and TgAQP1{sup +/+}/AQP0{sup -/-} lenses, fiber cell disorganization was evident.

Association of Perivascular Localization of Aquaporin-4 With Cognition and Alzheimer Disease in Aging Brains.

Science.gov (United States)

Zeppenfeld, Douglas M; Simon, Matthew; Haswell, J Douglas; D'Abreo, Daryl; Murchison, Charles; Quinn, Joseph F; Grafe, Marjorie R; Woltjer, Randall L; Kaye, Jeffrey; Iliff, Jeffrey J

2017-01-01

Cognitive impairment and dementia, including Alzheimer disease (AD), are common within the aging population, yet the factors that render the aging brain vulnerable to these processes are unknown. Perivascular localization of aquaporin-4 (AQP4) facilitates the clearance of interstitial solutes, including amyloid-β, through the brainwide network of perivascular pathways termed the glymphatic system, which may be compromised in the aging brain. To determine whether alterations in AQP4 expression or loss of perivascular AQP4 localization are features of the aging human brain and to define their association with AD pathology. Expression of AQP4 was analyzed in postmortem frontal cortex of cognitively healthy and histopathologically confirmed individuals with AD by Western blot or immunofluorescence for AQP4, amyloid-β 1-42, and glial fibrillary acidic protein. Postmortem tissue and clinical data were provided by the Oregon Health and Science University Layton Aging and Alzheimer Disease Center and Oregon Brain Bank. Postmortem tissue from 79 individuals was evaluated, including cognitively intact "young" individuals aged younger than 60 years (range, 33-57 years), cognitively intact "aged" individuals aged older than 60 years (range, 61-96 years) with no known neurological disease, and individuals older than 60 years (range, 61-105 years) of age with a clinical history of AD confirmed by histopathological evaluation. Forty-eight patient samples (10 young, 20 aged, and 18 with AD) underwent histological analysis. Sixty patient samples underwent Western blot analysis (15 young, 24 aged, and 21 with AD). Expression of AQP4 protein, AQP4 immunoreactivity, and perivascular AQP4 localization in the frontal cortex were evaluated. Expression of AQP4 was associated with advancing age among all individuals (R2 = 0.17; P = .003). Perivascular AQP4 localization was significantly associated with AD status independent of age (OR, 11.7 per 10% increase in localization; z�

Role of aquaporin and sodium channel in pleural water movement.

Science.gov (United States)

Jiang, Jinjun; Hu, Jie; Bai, Chunxue

2003-12-16

The role of the ENaC sodium channel and aquaporin-1 (AQP1) water channel on pleural fluid dynamics in mice was investigated. 0.25 ml of hypertonic or isosmolar fluid was infused into the pleural space in anesthetized wildtype and AQP1 null mice. Pleural fluid was sampled at specified times to quantify the osmolality and volume. The sodium channel activator terbutaline increased isosmolar fluid clearance by 90% while the sodium channel inhibitor amiloride decreased it by 15%, but had no effect on osmotically driven water transport. AQP1 deletion significantly decreased osmotic water transport in pleural space by twofold, but it had no effect on isosmolar fluid clearance. Pretreatment with dexamethasone increased pleural osmotic fluid entry by 25%, while intravenous injection of HgCl2 decreased osmotic pleural water movement by 43%. These results provided evidence for a role of a sodium channel in pleural fluid absorption; AQP1 plays a major role in osmotic liquid transport but it does not affect isosmolar fluid clearance.

Role of Aquaporin 0 in lens biomechanics.

Science.gov (United States)

Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

2015-07-10

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

Expression of aquaporin 3 in gills of the Atlantic killifish (Fundulus heteroclitus): Effects of seawater acclimation

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Jung, Dawoon; Sato, J. Denry; Shaw, Joseph R.; Stanton, Bruce A.

2011-01-01

Estuarine fish, such as the Atlantic killifish (Fundulus heteroclitus), are constantly and rapidly exposed to changes in salinity. Although ion transport in killifish gills during acclimation to increased salinity has been studied extensively, no studies have examined the role of aquaglyceroporin 3 (AQP3), a water, glycerol, urea, and ammonia transporter, during acclimation to increased salinity in this sentinel environmental model organism. The goal of this study was to test the hypothesis that transfer from freshwater to seawater decreases AQP3 gene and protein expression in the gill of killifish. Transfer from freshwater to seawater decreased AQP3 mRNA in the gill after 1 day, but had no effect on total gill AQP3 protein abundance as determined by western blot. Quantitative confocal immunocytochemistry confirmed western blot studies that transfer from freshwater to seawater did not change total AQP3 abundance in the gill; however, immunocytochemistry revealed that the amount of AQP3 in pillar cells of secondary lamellae decreased in seawater fish, whereas the amount of AQP3 in mitochondrion rich cells (MRC) in primary filaments of the gill increased in seawater fish. This response of AQP3 expression is unique to killifish compared to other teleosts. Although the role of AQP3 in the gill of killifish has not been completely elucidated, these results suggest that AQP3 may play an important role in the ability of killifish to acclimate to increased salinity. PMID:22193757

Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood-brain barrier: [17O]H2O JJVCPE MRI study.

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Huber, Vincent J; Igarashi, Hironaka; Ueki, Satoshi; Kwee, Ingrid L; Nakada, Tsutomu

2018-06-13

The blood-brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow-Robin space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow-Robin space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial space promoting circulation of interstitial fluid within the BBB.

Bioinformatics analysis and construction of phylogenetic tree of aquaporins from Echinococcus granulosus.

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Wang, Fen; Ye, Bin

2016-09-01

Cyst echinococcosis caused by the matacestodal larvae of Echinococcus granulosus (Eg), is a chronic, worldwide, and severe zoonotic parasitosis. The treatment of cyst echinococcosis is still difficult since surgery cannot fit the needs of all patients, and drugs can lead to serious adverse events as well as resistance. The screen of target proteins interacted with new anti-hydatidosis drugs is urgently needed to meet the prevailing challenges. Here, we analyzed the sequences and structure properties, and constructed a phylogenetic tree by bioinformatics methods. The MIP family signature and Protein kinase C phosphorylation sites were predicted in all nine EgAQPs. α-helix and random coil were the main secondary structures of EgAQPs. The numbers of transmembrane regions were three to six, which indicated that EgAQPs contained multiple hydrophobic regions. A neighbor-joining tree indicated that EgAQPs were divided into two branches, seven EgAQPs formed a clade with AQP1 from human, a "strict" aquaporins, other two EgAQPs formed a clade with AQP9 from human, an aquaglyceroporins. Unfortunately, homology modeling of EgAQPs was aborted. These results provide a foundation for understanding and researches of the biological function of E. granulosus.

Expression and localization of Aquaporin 1a in the sea-bass (Dicentrarchus labrax during ontogeny

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Ivone eGiffard-Mena

2011-07-01

Full Text Available The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32-48 post hatch, 15 - 25 mm and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87-100 post hatch, 38 - 48 mm, the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water than at lower salinity. These observations, in agreement with existing models, suggest that in sea water-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydratation in sea water, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies.

Bevacizumab exacerbates sinusoidal obstruction syndrome (SOS) in the animal model and increases MMP 9 production.

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Jafari, Azin; Matthaei, Hanno; Wehner, Sven; Tonguc, Tolga; Kalff, Jörg C; Manekeller, Steffen

2018-04-24

Thanks to modern multimodal treatment the ouctome of patients with colorectal cancer has experienced significant improvements. As a downside, agent specific side effects have been observed such as sinusoidal obstruction syndrome (SOS) after oxaliplatin chemotherapy (OX). Bevazicumab targeting VEGF is nowadays comprehensively used in combination protocols with OX but its impact on hepatotoxicity is thus far elusive and focus of the present study. After MCT administration 67% of animals developed SOS. GOT serum concentration significantly increased in animals developing SOS ( p SOS. In contrast, animals receiving VEGF developed SOS merely in 40% while increasing the VEGF dose led to a further decrease in SOS development to 25%. MMP 9 concentration in animals developing SOS was significantly higher compared to controls ( p SOS paralleled by MMP 9 production. Therefore, OX-Bevacizumab combination therapies should be administered with caution, especially if liver parenchyma damage is apparent. Male Sprague-Dawley rats were gavaged Monocrotaline (MCT) to induce SOS. Recombinant VEGF or an Anti-VEGF antibody was administered to MCT-treated rats and the hepatotoxic effect monitored in defined time intervals. MMP 9 expression in the liver was measured by ELISA.

Chronic cerebral hypoperfusion-induced impairment of Aβ clearance requires HB-EGF-dependent sequential activation of HIF1α and MMP9.

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Ashok, Anushruti; Rai, Nagendra Kumar; Raza, Waseem; Pandey, Rukmani; Bandyopadhyay, Sanghamitra

2016-11-01

Chronic cerebral hypoperfusion (CCH) manifests Alzheimer's Disease (AD) neuropathology, marked by increased amyloid beta (Aβ). Besides, hypoxia stimulates Heparin-binding EGF-like growth factor (HB-EGF) mRNA expression in the hippocampus. However, involvement of HB-EGF in CCH-induced Aβ pathology remains unidentified. Here, using Bilateral Common Carotid Artery Occlusion mouse model, we explored the mechanism of HB-EGF regulated Aβ induction in CCH. We found that HB-EGF inhibition suppressed, while exogenous-HB-EGF triggered hippocampal Aβ, proving HB-EGF-dependent Aβ increase. We also detected that HB-EGF affected the expression of primary Aβ transporters, receptor for advanced glycation end-products (RAGE) and lipoprotein receptor-related protein-1 (LRP-1), indicating impaired Aβ clearance across the blood-brain barrier (BBB). An HB-EGF-dependent loss in BBB integrity supported impaired Aβ clearance. The effect of HB-EGF on Amyloid Precursor Protein pathway was relatively insignificant, suggesting a lesser effect on Aβ generation. Delving into BBB disruption mechanism demonstrated HB-EGF-mediated stimulation of Matrix metalloprotease-9 (MMP9), which affected BBB via HB-EGF-ectodomain shedding and epidermal growth factor receptor activation. Examining the intersection of HB-EGF-regulated pathway and hypoxia revealed HB-EGF-dependent increase in transcription factor, Hypoxia-inducible factor-1alpha (HIF1α). Further, via binding to hypoxia-responsive elements in MMP9 gene, HIF1α stimulated MMP9 expression, and therefore appeared as a prominent intermediary in HB-EGF-induced BBB damage. Overall, our study reveals the essential role of HB-EGF in triggering CCH-mediated Aβ accumulation. The proposed mechanism involves an HB-EGF-dependent HIF1α increase, generating MMP9 that stimulates soluble-HB-EGF/EGFR-induced BBB disintegration. Consequently, CCH-mediated hippocampal RAGE and LRP-1 deregulation together with BBB damage impair Aβ transport and clearance

Molecular Characterization of Aquaporin 1 and Aquaporin 3 from the Gills of the African Lungfish, Protopterus annectens, and Changes in Their Branchial mRNA Expression Levels and Protein Abundance during Three Phases of Aestivation.

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Chng, You R; Ong, Jasmine L Y; Ching, Biyun; Chen, Xiu L; Hiong, Kum C; Wong, Wai P; Chew, Shit F; Lam, Siew H; Ip, Yuen K

2016-01-01

African lungfishes can undergo long periods of aestivation on land during drought. During aestivation, lungfishes are confronted with desiccation and dehydration, and their gills become non-functional and covered with a thick layer of dried mucus. Aquaporins (Aqps) are a superfamily of integral membrane proteins which generally facilitate the permeation of water through plasma membranes. This study aimed to obtain the complete cDNA coding sequences of aqp1 and aqp3 from the gills of Protopterus annectens , and to determine their branchial mRNA and protein expression levels during the induction, maintenance and arousal phases of aestivation. Dendrogramic analyses of the deduced Aqp1 and Aqp3 amino acid sequences of P. annectens revealed their close relationships with those of Latimeria chalumnae and tetrapods. During the induction phase, there were significant decreases in the transcript levels of aqp1 and aqp3 in the gills of P. annectens , but the branchial Aqp1 and Aqp3 protein abundance remained unchanged. As changes in transcription might precede changes in translation, this could be regarded as an adaptive response to decrease the protein abundance of Aqp1 and Aqp3 in the subsequent maintenance phase of aestivation. As expected, the branchial transcript levels and protein abundance of aqp1 /Aqp1 and aqp3 /Aqp3 were significantly down-regulated during the maintenance phase, probably attributable to the shutdown of branchial functions and the cessation of volume regulation of branchial epithelial cells. Additionally, these changes could reduce the loss of water through branchial epithelial surfaces, supplementing the anti-desiccating property of the dried mucus. Upon arousal, it was essential for the lungfish to restore branchial functions. Indeed, the protein abundance of Aqp1 recovered partially, with complete recovery of mRNA expression level and protein abundance of Aqp3, in the gills of P. annectens after 3 days of arousal. These results provide insights

Superresolution Imaging of Aquaporin-4 Cluster Size in Antibody-Stained Paraffin Brain Sections.

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Smith, Alex J; Verkman, Alan S

2015-12-15

The water channel aquaporin-4 (AQP4) forms supramolecular clusters whose size is determined by the ratio of M1- and M23-AQP4 isoforms. In cultured astrocytes, differences in the subcellular localization and macromolecular interactions of small and large AQP4 clusters results in distinct physiological roles for M1- and M23-AQP4. Here, we developed quantitative superresolution optical imaging methodology to measure AQP4 cluster size in antibody-stained paraffin sections of mouse cerebral cortex and spinal cord, human postmortem brain, and glioma biopsy specimens. This methodology was used to demonstrate that large AQP4 clusters are formed in AQP4(-/-) astrocytes transfected with only M23-AQP4, but not in those expressing only M1-AQP4, both in vitro and in vivo. Native AQP4 in mouse cortex, where both isoforms are expressed, was enriched in astrocyte foot-processes adjacent to microcapillaries; clusters in perivascular regions of the cortex were larger than in parenchymal regions, demonstrating size-dependent subcellular segregation of AQP4 clusters. Two-color superresolution imaging demonstrated colocalization of Kir4.1 with AQP4 clusters in perivascular areas but not in parenchyma. Surprisingly, the subcellular distribution of AQP4 clusters was different between gray and white matter astrocytes in spinal cord, demonstrating regional specificity in cluster polarization. Changes in AQP4 subcellular distribution are associated with several neurological diseases and we demonstrate that AQP4 clustering was preserved in a postmortem human cortical brain tissue specimen, but that AQP4 was not substantially clustered in a human glioblastoma specimen despite high-level expression. Our results demonstrate the utility of superresolution optical imaging for measuring the size of AQP4 supramolecular clusters in paraffin sections of brain tissue and support AQP4 cluster size as a primary determinant of its subcellular distribution. Copyright © 2015 Biophysical Society

Up-regulation of Store-operated Ca2+ Entry and Nuclear Factor of Activated T Cells Promote the Acinar Phenotype of the Primary Human Salivary Gland Cells.

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Jang, Shyh-Ing; Ong, Hwei Ling; Liu, Xibao; Alevizos, Ilias; Ambudkar, Indu S

2016-04-15

The signaling pathways involved in the generation and maintenance of exocrine gland acinar cells have not yet been established. Primary human salivary gland epithelial cells, derived from salivary gland biopsies, acquired an acinar-like phenotype when the [Ca(2+)] in the serum-free medium (keratinocyte growth medium, KGM) was increased from 0.05 mm (KGM-L) to 1.2 mm (KGM-H). Here we examined the mechanism underlying this Ca(2+)-dependent generation of the acinar cell phenotype. Compared with cells in KGM-L, those in KGM-H display enhancement of Orai1, STIM1, STIM2, and nuclear factor of activated T cells 1 (NFAT1) expression together with an increase in store-operated Ca(2+) entry (SOCE), SOCE-dependent nuclear translocation of pGFP-NFAT1, and NFAT-dependent but not NFκB-dependent gene expression. Importantly, AQP5, an acinar-specific protein critical for function, is up-regulated in KGM-H via SOCE/NFAT-dependent gene expression. We identified critical NFAT binding motifs in the AQP5 promoter that are involved in Ca(2+)-dependent up-regulation of AQP5. These important findings reveal that the Ca(2+)-induced switch of salivary epithelial cells to an acinar-like phenotype involves remodeling of SOCE and NFAT signaling, which together control the expression of proteins critically relevant for acinar cell function. Our data provide a novel strategy for generating and maintaining acinar cells in culture. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Cholesterol can modulate mitochondrial aquaporin-8 expression in human hepatic cells.

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Danielli, Mauro; Capiglioni, Alejo M; Marrone, Julieta; Calamita, Giuseppe; Marinelli, Raúl A

2017-05-01

Hepatocyte mitochondrial aquaporin-8 (mtAQP8) works as a multifunctional membrane channel protein that facilitates the uptake of ammonia for its detoxification to urea as well as the mitochondrial release of hydrogen peroxide. Since early oligonucleotide microarray studies in liver of cholesterol-fed mice showed an AQP8 downregulation, we tested whether alterations of cholesterol content per se modulate mtAQP8 expression in human hepatocyte-derived Huh-7 cells. Cholesterol loading with methyl-β-cyclodextrin (mβCD):cholesterol complexes downregulated the proteolytic activation of cholesterol-responsive sterol regulatory element-binding protein (SREBP) transcriptions factors 1 and 2, and the expression of the target gene 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR). Under such conditions, mtAQP8 mRNA and protein expressions were significantly reduced. In contrast, cholesterol depletion using mβCD alone increased SREBP-1 and 2 activation and upregulated HMGCR and mtAQP8 mRNA and protein expressions. The results suggest that cholesterol can regulate transcriptionally human hepatocyte mtAQP8 expression likely via SREBPs. The functional implications of our findings are discussed. © 2017 IUBMB Life, 69(5):341-346, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Does exercise deprivation increase the tendency towards morphine dependence in rats?

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Nakhaee, Mohammad Reza; Sheibani, Vahid; Ghahraman Tabrizi, Kourosh; Marefati, Hamid; Bahreinifar, Sareh; Nakhaee, Nouzar

2010-01-01

Exercise deprivation has been concluded to have some negative effectson psychological well-being. This study was conducted to find outwhether exercise deprivation may lead to morphine dependence in rats. Forty male Wistar rats weighing 162 ± 9 g were housed in clear plasticcages in groups of two under standard laboratory conditions. The studyhad two phases. In phase I, the animals were randomly divided intoexercised (E) and unexercised (UE) groups (n = 20 each) and treadmillrunning was performed based on a standard protocol for three weeks. Atthe end of the training period, plasma β-endorphin levels weredetermined in four rats from each group. In phase II, the animals wereprovided with two bottles, one containing tap water and the other 25mg/l morphine sulfate in tap water for a total of 12 weeks. At the end ofthis phase naloxone was injected intraperitoneally to precipitatemorphine withdrawal. THERE WAS NO SIGNIFICANT DIFFERENCE BETWEEN UE AND E GROUPS INMORPHINE CONSUMPTION (MG/KG/WK) [ F(1,14) = 0.2, P = 0.690; time:F(11,154) =18.72, P exercise does not increasethe tendency of morphine dependence in rats.

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-α-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells

International Nuclear Information System (INIS)

Yang, Chuen-Mao; Lee, I-Ta; Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der

2013-01-01

TNF-α plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-α in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-α-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-α induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-α-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-κB (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47 phox , p42, p38, JNK1, p65, or PYK2. Moreover, TNF-α markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-α-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-κB (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-α-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-α-stimulated MAPKs and NF-κB activation. Thus, in H9c2 cells, we are the first to show that TNF-α-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-κB cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-α-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-α on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-α induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-α induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF-α induces

Clonorchis sinensis excretory-secretory products regulate migration and invasion in cholangiocarcinoma cells via extracellular signal-regulated kinase 1/2/nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

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Pak, Jhang Ho; Shin, Jimin; Song, In-Sung; Shim, Sungbo; Jang, Sung-Wuk

2017-01-01

Matrix metalloproteinase-9 plays an important role in the invasion and metastasis of various types of cancer cells. We have previously reported that excretory-secretory products from Clonorchis sinensis increases matrix metalloproteinase-9 expression. However, the regulatory mechanisms through which matrix metalloproteinase-9 expression affects cholangiocarcinoma development remain unclear. In the current study, we examined the potential role of excretory-secretory products in regulating the migration and invasion of various cholangiocarcinoma cell lines. We demonstrated that excretory-secretory products significantly induced matrix metalloproteinase-9 expression and activity in a concentration-dependent manner. Reporter gene and chromatin immunoprecipitation assays showed that excretory-secretory products induced matrix metalloproteinase-9 expression by enhancing the activity of nuclear factor-kappa B. Moreover, excretory-secretory products induced the degradation and phosphorylation of IκBα and stimulated nuclear factor-kappa B p65 nuclear translocation, which was regulated by extracellular signal-regulated kinase 1/2. Taken together, our findings indicated that the excretory-secretory product-dependent enhancement of matrix metalloproteinase-9 activity and subsequent induction of IκBα and nuclear factor-kappa B activities may contribute to the progression of cholangiocarcinoma. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Energy drink consumption and increased risk for alcohol dependence.

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Arria, Amelia M; Caldeira, Kimberly M; Kasperski, Sarah J; Vincent, Kathryn B; Griffiths, Roland R; O'Grady, Kevin E

2011-02-01

Energy drinks are highly caffeinated beverages that are increasingly consumed by young adults. Prior research has established associations between energy drink use and heavier drinking and alcohol-related problems among college students. This study investigated the extent to which energy drink use might pose additional risk for alcohol dependence over and above that from known risk factors. Data were collected via personal interview from 1,097 fourth-year college students sampled from 1 large public university as part of an ongoing longitudinal study. Alcohol dependence was assessed according to DSM-IV criteria. After adjustment for the sampling design, 51.3%(wt) of students were classified as "low-frequency" energy drink users (1 to 51 days in the past year) and 10.1%(wt) as "high-frequency" users (≥52 days). Typical caffeine consumption varied widely depending on the brand consumed. Compared to the low-frequency group, high-frequency users drank alcohol more frequently (141.6 vs. 103.1 days) and in higher quantities (6.15 vs. 4.64 drinks/typical drinking day). High-frequency users were at significantly greater risk for alcohol dependence relative to both nonusers (AOR = 2.40, 95% CI = 1.27 to 4.56, p = 0.007) and low-frequency users (AOR = 1.86, 95% CI = 1.10, 3.14, p = 0.020), even after holding constant demographics, typical alcohol consumption, fraternity/sorority involvement, depressive symptoms, parental history of alcohol/drug problems, and childhood conduct problems. Low-frequency energy drink users did not differ from nonusers on their risk for alcohol dependence. Weekly or daily energy drink consumption is strongly associated with alcohol dependence. Further research is warranted to understand the possible mechanisms underlying this association. College students who frequently consume energy drinks represent an important target population for alcohol prevention. Copyright © 2010 by the Research Society on Alcoholism.

Intermittent hypoxia alters dose dependent caffeine effects on renal prostanoids and receptors in neonatal rats.

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Beharry, Kay D; Cai, Charles L; Soontarapornchai, Kultida; Ahmad, Taimur; Valencia, Gloria B; Aranda, Jacob V

2018-01-01

Caffeine, one of the most commonly prescribed drugs in preterm neonates, is given in standard or suprapharmacologic doses. Although known as a diuretic, its effects in the neonatal kidneys are not well studied. We tested the hypothesis that neonatal intermittent hypoxia (IH) and high caffeine doses (HCD) alter renal regulators of vasomotor tone and water balance. Newborn rats were randomized to room air, hyperoxia, or IH and treated with standard or high caffeine doses; or placebo saline. Renal prostanoids; histopathology; and cyclooxygenase (COX), prostanoid receptor, and aquaporin (AQP) immunoreactivity were determined. HCD in IH caused severe pathological changes in the glomeruli and proximal tubules, consistent with acute kidney injury. This was associated with reductions in anthropometric growth, PGI 2, and IP, DP, and AQP-4 immunoreactivity, well as a robust increase in COX-2, suggesting that the use of HCD should be avoided in preterm infants who experience frequent IH episodes. Published by Elsevier Inc.

Response of Vallisneria natans to Increasing Nitrogen Loading Depends on Sediment Nutrient Characteristics

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Jiao Gu

2016-11-01

Full Text Available High nitrogen (N loading may contribute to recession of submerged macrophytes in shallow lakes; yet, its influences vary depending on environmental conditions. In August 2013, we conducted a 28-day factorial-designed field mesocosm experiment in Lake Taihu at the Taihu Laboratory for Lake Ecosystem Research (TLLER to examine the effects of high N loading on the growth of Vallisneria natans in systems with contrasting sediment types. We ran the experiments with two levels of nutrient loading—present-day external nutrient loading (average P: 5 μg·L−1·day−1, N: 130 μg·L−1·day−1 and P: 5 μg·L−1·day−1, and with three times higher N loading (N: 390 μg·L−1·day−1 and used sediment with two contrasting nutrient levels. V. natans growth decreased significantly with increasing N loading, the effect being dependent, however, on the nutrient status of the sediment. In low nutrient sediment, relative growth rates, leaf biomass and root biomass decreased by 11.9%, 18.2% and 23.3%, respectively, at high rather than low N loading, while the decline was larger (44.0%, 32.7% and 41.8%, respectively when using high nutrient sediment. The larger effect in the nutrient-rich sediment may reflect an observed higher shading of phytoplankton and excess nutrient accumulation in plant tissue, though potential toxic effects of the high-nutrient sediment may also have contributed. Our study confirms the occurrence of a negative effect of increasing N loading on submerged plant growth in shallow nutrient-enriched lakes and further shows that this effect is augmented when the plants grow in nutrient-rich sediment. External N control may, therefore, help to protect or restore submerged macrophytes, especially when the sediment is enriched with nutrients and organic matter.

Performance characteristics of CA 19-9 radioimmunoassay and clinical significance of serum CA 19-9 assay in patients with malignancy

International Nuclear Information System (INIS)

Kim, S.E.; Shong, Y.K.; Cho, B.Y.; Kim, N.K.; Koh, C.S.; Lee, M.H.; Hong, K.S.

1985-01-01

To evaluate the performance characteristics of CA 19-9 radioimmunoassay and the clinical significance of serum CA 19-9 assay in patients with malignancy, serum CA 19-9 levels were measured by radioimmunoassay using monoclonal antibody in 135 normal controls, 81 patients with various untreated malignancy, 9 patients of postoperative colon cancer without recurrence and 20 patients with benign gastrointestinal diseases, who visited Seoul National University Hospital from June, 1984 to March, 1985. (Author)

P2Y12 Receptor Localizes in the Renal Collecting Duct and Its Blockade Augments Arginine Vasopressin Action and Alleviates Nephrogenic Diabetes Insipidus.

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Zhang, Yue; Peti-Peterdi, Janos; Müller, Christa E; Carlson, Noel G; Baqi, Younis; Strasburg, David L; Heiney, Kristina M; Villanueva, Karie; Kohan, Donald E; Kishore, Bellamkonda K

2015-12-01

P2Y12 receptor (P2Y12-R) signaling is mediated through Gi, ultimately reducing cellular cAMP levels. Because cAMP is a central modulator of arginine vasopressin (AVP)-induced water transport in the renal collecting duct (CD), we hypothesized that if expressed in the CD, P2Y12-R may play a role in renal handling of water in health and in nephrogenic diabetes insipidus. We found P2Y12-R mRNA expression in rat kidney, and immunolocalized its protein and aquaporin-2 (AQP2) in CD principal cells. Administration of clopidogrel bisulfate, an irreversible inhibitor of P2Y12-R, significantly increased urine concentration and AQP2 protein in the kidneys of Sprague-Dawley rats. Notably, clopidogrel did not alter urine concentration in Brattleboro rats that lack AVP. Clopidogrel administration also significantly ameliorated lithium-induced polyuria, improved urine concentrating ability and AQP2 protein abundance, and reversed the lithium-induced increase in free-water excretion, without decreasing blood or kidney tissue lithium levels. Clopidogrel administration also augmented the lithium-induced increase in urinary AVP excretion and suppressed the lithium-induced increase in urinary nitrates/nitrites (nitric oxide production) and 8-isoprostane (oxidative stress). Furthermore, selective blockade of P2Y12-R by the reversible antagonist PSB-0739 in primary cultures of rat inner medullary CD cells potentiated the expression of AQP2 and AQP3 mRNA, and cAMP production induced by dDAVP (desmopressin). In conclusion, pharmacologic blockade of renal P2Y12-R increases urinary concentrating ability by augmenting the effect of AVP on the kidney and ameliorates lithium-induced NDI by potentiating the action of AVP on the CD. This strategy may offer a novel and effective therapy for lithium-induced NDI. Copyright © 2015 by the American Society of Nephrology.

Weak ferromagnetism and temperature dependent dielectric properties of Zn{sub 0.9}Ni{sub 0.1}O diluted magnetic semiconductor

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Raju [Department of Electrical and Electronic Engineering, Shahjalal University of Science and Technology, Sylhet 3114 (Bangladesh); Department of Applied Physics, Electronics and Communication Engineering, University of Dhaka, Dhaka 1000 (Bangladesh); Moslehuddin, A.S.M.; Mahmood, Zahid Hasan [Department of Applied Physics, Electronics and Communication Engineering, University of Dhaka, Dhaka 1000 (Bangladesh); Hossain, A.K.M. Akther, E-mail: akmhossain@phy.buet.ac.bd [Department of Physics, Bangladesh University of Engineering and Technology, Dhaka 1000 (Bangladesh)

2015-03-15

Highlights: • Single phase wurtzite structure was confirmed from XRD analysis. • Weak ferromagnetic behaviour at room temperature. • Pure semiconducting properties confirmed from temperature dependent conductivity. • Smaller dielectric properties at higher frequency. • Possible potential application in high frequency spintronic devices. - Abstract: In this study the room temperature ferromagnetic behaviour and dielectric properties of ZnO based diluted magnetic semiconductor (DMS) have been investigated using nominal chemical composition Zn{sub 0.9}Ni{sub 0.1}O. The X-ray diffraction analysis confirmed formation of single phase hexagonal wurtzite structure. An increase in grain size with increasing sintering temperature was observed from scanning electron microscopy. Field dependent DC magnetization values indicated dominant paramagnetic ordering along with a slight ferromagnetic behaviour at room temperature. Frequency dependent complex initial permeability showed some positive values around 12 at room temperature. In dielectric measurement, an increasing trend of complex permittivity, loss tangent and ac conductivity with increasing temperature were observed. The temperature dependent dispersion curves of dielectric properties revealed clear relaxation at higher temperature. Frequency dependent ac conductivity was found to increase with frequency whereas complex permittivity and loss tangent showed an opposite trend.

Serosal-to-mucosal urea flux across the isolated ruminal epithelium is mediated via urea transporter-B and aquaporins when Holstein calves are abruptly changed to a moderately fermentable diet.

Science.gov (United States)

Walpole, M E; Schurmann, B L; Górka, P; Penner, G B; Loewen, M E; Mutsvangwa, T

2015-02-01

Jsm-urea tended to increase linearly as the duration of adaptation to MGD increased, with the lowest Jsm-urea being observed in animals fed CON [107.7 nmol/(cm(2) × h)] and the highest for those fed the MGD for 21 d [144.2 nmol/(cm(2) × h)]. Phloretin-insensitive Jsm-urea tended to increase linearly as the duration of adaptation to MGD increased, whereas NiCl2-insensitive Jsm-urea tended to be affected by diet. Gene transcript abundance for AQP-3 and UT-B in ruminal epithelium increased linearly as the duration of MGD adaptation increased. For AQP-7 and AQP-10, gene transcript abundance in animals that were fed the MGD was greater compared with that of CON animals. These results demonstrate that both AQP and UT-B play significant functional roles in urea transport, and they may play a role in urea transport during dietary adaptation to fermentable carbohydrates. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

SwissProt search result: AK061782 [KOME

Lifescience Database Archive (English)

Full Text Available AK061782 001-039-E03 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-45 ...

SwissProt search result: AK104464 [KOME

Lifescience Database Archive (English)

Full Text Available AK104464 006-301-C06 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-28 ...

SwissProt search result: AK099616 [KOME

Lifescience Database Archive (English)

Full Text Available AK099616 J013050J20 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel pr...otein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-28 ...

SwissProt search result: AK099141 [KOME

Lifescience Database Archive (English)

Full Text Available AK099141 J023055A02 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel pr...otein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-28 ...

SwissProt search result: AK099015 [KOME

Lifescience Database Archive (English)

Full Text Available AK099015 J013116H02 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel pr...otein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-28 ...

SwissProt search result: AK107700 [KOME

Lifescience Database Archive (English)

Full Text Available AK107700 002-132-C10 (P47865) Aquaporin-1 (AQP-1) (Aquaporin-CHIP) (Water channel p...rotein for red blood cells and kidney proximal tubule) (Water channel protein CHIP29) AQP1_BOVIN 9e-18 ...

Aquaporin 0 plays a pivotal role in refractive index gradient development in mammalian eye lens to prevent spherical aberration

International Nuclear Information System (INIS)

Kumari, S. Sindhu; Varadaraj, Kulandaiappan

2014-01-01

scanning electron micrographs of lenses of both mouse models showed increased extracellular space between fiber cells. Water content determination study showed increase in water in the lenses of these mouse models. In summary, lens transparency, CTCA and compact packing of fiber cells were affected due to the loss of 50% AQP0 leading to larger extracellular space, more water content and SA, possibly due to alteration in RING. To our knowledge, this is the first report identifying the role of AQP0 in RING development to ward off lens SA during focusing

In vivo imaging reveals rapid astrocyte depletion and axon damage in a model of neuromyelitis optica-related pathology

DEFF Research Database (Denmark)

Herwerth, Marina; Kalluri, Sudhakar Reddy; Srivastava, Rajneesh

2016-01-01

IgG autoantibodies against aquaporin-4 (AQP4), an astrocytic water channel. Antibodies against AQP4 can damage astrocytes via complement, but NMO histopathology also shows demyelination, and - importantly - axon injury, which may determine permanent deficits following NMO relapses. The dynamics...... antibodies in mice. RESULTS: We found that human AQP4 antibodies caused acute astrocyte depletion with initial oligodendrocyte survival. Within two hours of antibody application, we observed secondary axon injury in the form of progressive swellings. Astrocyte toxicity and axon damage were dependent on AQP4...... antibody concentration and complement, specifically C1q. INTERPRETATION: In vivo imaging of the spinal cord reveals the swift development of NMO-related acute axon injury following AQP4 antibody-mediated astrocyte depletion. This approach will be useful in studying the mechanisms underlying the spread...

Isoginkgetin inhibits tumor cell invasion by regulating phosphatidylinositol 3-kinase/Akt-dependent matrix metalloproteinase-9 expression.

Science.gov (United States)

Yoon, Sang-Oh; Shin, Sejeong; Lee, Ho-Jae; Chun, Hyo-Kon; Chung, An-Sik

2006-11-01

Matrix metalloproteinase (MMP)-9 plays a key role in tumor invasion. Inhibitors of MMP-9 were screened from Metasequoia glyptostroboides (Dawn redwood) and one potent inhibitor, isoginkgetin, a biflavonoid, was identified. Noncytotoxic levels of isoginkgetin decreased MMP-9 production profoundly, but up-regulated the level of tissue inhibitor of metalloproteinase (TIMP)-1, an inhibitor of MMP-9, in HT1080 human fibrosarcoma cells. The major mechanism of Ras-dependent MMP-9 production in HT1080 cells was phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor-kappaB (NF-kappaB) activation. Expression of dominant-active H-Ras and p85 (a subunit of PI3K) increased MMP-9 activity, whereas dominant-negative forms of these molecules decreased the level of MMP-9. H-Ras did not increase MMP-9 in the presence of a PI3K inhibitor, LY294002, and a NF-kappaB inhibitor, SN50. Further studies showed that isoginkgetin regulated MMP-9 production via PI3K/Akt/NF-kappaB pathway, as evidenced by the findings that isoginkgetin inhibited activities of both Akt and NF-kappaB. PI3K/Akt is a well-known key pathway for cell invasion, and isoginkgetin inhibited HT1080 tumor cell invasion substantially. Isoginkgetin was also quite effective in inhibiting the activities of Akt and MMP-9 in MDA-MB-231 breast carcinomas and B16F10 melanoma. Moreover, isoginkgetin treatment resulted in marked decrease in invasion of these cells. In summary, PI3K/Akt is a major pathway for MMP-9 expression and isoginkgetin markedly decreased MMP-9 expression and invasion through inhibition of this pathway. This suggests that isoginkgetin could be a potential candidate as a therapeutic agent against tumor invasion.

Aquaporin 4 as a NH3 Channel

DEFF Research Database (Denmark)

Assentoft, Mette; Kaptan, Shreyas; Schneider, Hans-Peter

2016-01-01

-brain-interface, participate in the exchange of ammonia, which is required to sustain the glutamate-glutamine cycle. Here we observe that AQP4-expressing Xenopus oocytes display a reflection coefficient NH4Cl at pH 8.0, at which pH an increased amount of the ammonia occurs in the form of NH3 Taken together with an NH4......Cl-mediated intracellular alkalization (or lesser acidification) of AQP4-expressing oocytes, these data suggest that NH3 is able to permeate the pore of AQP4. Exposure to NH4Cl increased the membrane currents to a similar extent in uninjected oocytes and in oocytes expressing AQP4, indicating...... that the ionic NH4 (+) did not permeate AQP4. Molecular dynamics simulations revealed partial pore permeation events of NH3 but not of NH4 (+) and a reduced energy barrier for NH3 permeation through AQP4 compared with that of a cholesterol-containing lipid bilayer, suggesting AQP4 as a favored transmembrane...

Effects of aquaporin 4 and inward rectifier potassium channel 4.1 on medullospinal edema after methylprednisolone treatment to suppress acute spinal cord injury in rats.

Science.gov (United States)

Li, Ye; Hu, Haifeng; Liu, Jingchen; Zhu, Qingsan; Gu, Rui

2018-02-01

To investigate the effects of aquaporin 4 (AQP4) and inward rectifier potassium channel 4.1 (Kir4.1) on medullospinal edema after treatment with methylprednisolone (MP) to suppress acute spinal cord injury (ASCI) in rats. Sprague Dawley rats were randomly divided into control, sham, ASCI, and MP-treated ASCI groups. After the induction of ASCI, we injected 30 mg/kg MP via the tail vein at various time points. The Tarlov scoring method was applied to evaluate neurological symptoms, and the wet-dry weights method was applied to measure the water content of the spinal cord. The motor function score of the ASCI group was significantly lower than that of the sham group, and the spinal water content was significantly increased. In addition, the levels of AQP4 and Kir4.1 were significantly increased, as was their degree of coexpression. Compared with that in the ASCI group, the motor function score and the water content were significantly increased in the MP group; in addition, the expression and coexpression of AQP4 and Kir4.1 were significantly reduced. Methylprednisolone inhibited medullospinal edema in rats with acute spinal cord injury, possibly by reducing the coexpression of aquaporin 4 and Kir4.1 in medullospinal tissues.

The Role of Aquaporin 1 Activated by cGMP in Myocardial Edema Caused by Cardiopulmonary Bypass in Sheep

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Fang-bao Ding

2013-11-01

Full Text Available Background/Aims: Most cardiac procedures involve the use of cardiopulmonary bypass (CPB, which pumps oxygenated blood to the body while the heart and lungs are isolated. CPB can cause profound alterations V in the homeostasis of physiological fluids, which often results in myocardial edema. In our study, we used sheep CPB model of in vivo and in vitro to assess the relationship between cGMP and AQP1 during CPB. Methods: ODQ, a specific inhibitor of soluble guanylate cyclase (sGC, was used to treat the CPB animals or cardiomyocytes. Left ventricular function of each group was determined by pressure-volume system. Water content of myocardial tissue was assessed by dry-wet weight, and cardiomyocytes water permeability was also calculated. The concentration of cGMP was determined by Radioimmunoassay (RIA. mRNA and protein expression of AQP1 were detected by real-time PCR and western blot, respectively. Results: The relative expression level of AQP1 mRNA and protein at each time point (0, 6, 12, 24 or 48 h after CPB was significantly increased (1.18-fold at 12 h, 1.77-fold at 24 h and 2.18-fold at 48h compared with each sham group, the protein expression of AQP1 also showed a rising trend after CPB. The degree of myocardial edema (75.1% at 12 h, 79.3% at 24 h and 81.0% at 48h increased following the CPB surgery. The mRNA expression level of AQP1 was significantly decreased by 39.7% (pin vitro experiments showed the same changing trends as in vivo. Conclusion: cGMP pathway controls water channels and then affects water intake during CPB through an AQP1-mediated pathway.

The significance of MMP-9 examination in serum from embryo of gastric cancer model

International Nuclear Information System (INIS)

Liu Zhan; Zhao Xuejian; Wang Lu; Li Yulin; Zhang Lihong; Zhang Hong

2003-01-01

Objective: To investigate the changes matrix metalloproteinase-9 (MMP-9) content from sera of chick embryos during the progression of transformed models of gastric cancer cells on chorioallantoic membrane (CAM). Methods: Morphometric investigation method was used to study the tumor generation on CAM; Enzyme-linked immunosorbent assay (ELISA) method was used to test MMP-9 concentrations in chick embryos'sera transferred by cancer cells at different points of time; the relationship between MMP-9 and cancer biological characteristics was analyzed. Results: In the group of 1 x 10 6 ·ml -1 gastric cancer cells, a single clot which could be seen by naked eyes appeared at 72 hours after inoculation. With the time going on, the volumes of the clot became larger and larger, and the neovessels on CAM accumulated to the clot. In the group of 1 x 10 6 ·ml -1 gastric cancer cells, the MMP-9 content in sera extremely increased at 72 hours after inoculation and increased continuously till the maxim at 7 days after inoculation. Conclusion: The whole progression of cancer development is accompanied with the increase of MMP-9 concentration. This model is feasible to study the characteristics of gastric cancer

Evidence of Positive Selection of Aquaporins Genes from Pontoporia blainvillei during the Evolutionary Process of Cetaceans.

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Simone Lima São Pedro

Full Text Available Marine mammals are well adapted to their hyperosmotic environment. Several morphological and physiological adaptations for water conservation and salt excretion are known to be present in cetaceans, being responsible for regulating salt balance. However, most previous studies have focused on the unique renal physiology of marine mammals, but the molecular bases of these mechanisms remain poorly explored. Many genes have been identified to be involved in osmotic regulation, including the aquaporins. Considering that aquaporin genes were potentially subject to strong selective pressure, the aim of this study was to analyze the molecular evolution of seven aquaporin genes (AQP1, AQP2, AQP3, AQP4, AQP6, AQP7, and AQP9 comparing the lineages of cetaceans and terrestrial mammals.Our results demonstrated strong positive selection in cetacean-specific lineages acting only in the gene for AQP2 (amino acids 23, 83, 107,179, 180, 181, 182, whereas no selection was observed in terrestrial mammalian lineages. We also analyzed the changes in the 3D structure of the aquaporin 2 protein. Signs of strong positive selection in AQP2 sites 179, 180, 181, and 182 were unexpectedly identified only in the baiji lineage, which was the only river dolphin examined in this study. Positive selection in aquaporins AQP1 (45, AQP4 (74, AQP7 (342, 343, 356 was detected in cetaceans and artiodactyls, suggesting that these events are not related to maintaining water and electrolyte homeostasis in seawater.Our results suggest that the AQP2 gene might reflect different selective pressures in maintaining water balance in cetaceans, contributing to the passage from the terrestrial environment to the aquatic. Further studies are necessary, especially those including other freshwater dolphins, who exhibit osmoregulatory mechanisms different from those of marine cetaceans for the same essential task of maintaining serum electrolyte balance.

Double transduction of a Cre/LoxP lentiviral vector: a simple method to generate kidney cell-specific knockdown mice.

Science.gov (United States)

Nam, Bo Young; Kim, Dong Ki; Park, Jung Tak; Kang, Hye-Young; Paeng, Jisun; Kim, Seonghun; Park, Jimin; Um, Jae Eun; Oh, Hyung Jung; Han, Seung Hyeok; Yoo, Tae-Hyun; Kang, Shin-Wook

2015-12-15

In a lentivirus-based gene delivery system, the incorporated gene is continuously expressed for a long time. In this study, we devised a simple way to knock down a specific gene in a kidney cell-specific pattern in adult mice by lentivirus-assisted transfer of short hairpin RNA (shRNA). Kidney collecting duct (CD)-specific aquaporin-3 (AQP3)-knockdown mice were generated by consecutive injection of Hoxb7-Cre-expressing lentivirus (LV-Hoxb7 Cre) and loxP-AQP3 shRNA-expressing lentivirus (LV-loxP shAQP3) in adult C57BL6/J mice. LV-Hoxb7 Cre was designed to express mCherry, while LV-loxP shAQP3 was designed with a floxed enhanced green fluorescent protein (EGFP)-tagged stop sequence, and thus EGFP would be expressed only in the absence of Cre recombination. In mice treated with LV-Hoxb7 Cre alone, mCherry protein expression, which indicates the presence of Cre recombinase, occurred only in CD cells. However, LV-loxP shAQP3 injection alone resulted in an increase in EGFP expression in all kidney cells, indicating the transcription of the floxed region. When LV-Hoxb7 Cre and LV-loxP shAQP3 were sequentially transduced, EGFP expression was attenuated while mCherry expression was sustained in CD cells, demonstrating a CD cell-specific recombination of the floxed region. AQP3 expression in mice injected with LV-Hoxb7 Cre or LV-loxP shAQP3 alone did not differ, but consecutive injection of LV-Hoxb7 Cre and LV-loxP shAQP3 significantly reduced AQP3 expression in CD cells. However, the expression levels of AQP3 were not altered in other cell types. Double transduction of Cre- and loxP-based lentivirus can easily generate kidney cell-specific knockdown mice, and this method might be applicable to other species. Copyright © 2015 the American Physiological Society.

Immunohistochemical evalulation of activated Ras and Rac1 as potential downstream effectors of aquaporin-5 in breast cancer in vivo.

Science.gov (United States)

Jensen, Helene H; Login, Frédéric H; Park, Ji-Young; Kwon, Tae-Hwan; Nejsum, Lene N

2017-11-25

Aberrant levels of aquaporin-5 (AQP5) expression have been observed in several types of cancer, including breast cancer, where AQP5 overexpression is associated with metastasis and poor prognosis. In cultured cancer cells, AQP5 facilitates cell migration and activates Ras signaling. Both increased cell migration and Ras activation are associated with cancer metastasis, but so far it is unknown if AQP5 also affects these processes in vivo. Therefore, we investigated if high AQP5 expression in breast cancer tissue correlated with increased activation of Ras and of Rac1, which is a GTPase also involved in cell migration. This was accomplished by immunohistochemical analysis of invasive ductal carcinoma of breast tissue sections from human patients, followed by qualitative and quantitative correlation analysis between AQP5 and activated Ras and Rac1. Immunohistochemistry revealed that activation of Ras and Rac1 was positively correlated. There was, however, no correlation between high AQP5 expression and activation of Ras, whereas a nonsignificant, but positive, tendency between the levels of AQP5 and activated Rac1 levels was observed. In summary, this is the first report that correlates AQP5 expression levels to downstream signaling partners in breast cancer tissue sections. The results suggest Rac1 as a potential downstream signaling partner of AQP5 in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

Voluntary Exercise Promotes Glymphatic Clearance of Amyloid Beta and Reduces the Activation of Astrocytes and Microglia in Aged Mice.

Science.gov (United States)

He, Xiao-Fei; Liu, Dong-Xu; Zhang, Qun; Liang, Feng-Ying; Dai, Guang-Yan; Zeng, Jin-Sheng; Pei, Zhong; Xu, Guang-Qing; Lan, Yue

2017-01-01

Age is characterized by chronic inflammation, leading to synaptic dysfunction and dementia because the clearance of protein waste is reduced. The clearance of proteins depends partly on the permeation of the blood-brain barrier (BBB) or on the exchange of water and soluble contents between the cerebrospinal fluid (CSF) and the interstitial fluid (ISF). A wealth of evidence indicates that physical exercise improves memory and cognition in neurodegenerative diseases during aging, such as Alzheimer's disease (AD), but the influence of physical training on glymphatic clearance, BBB permeability and neuroinflammation remains unclear. In this study, glymphatic clearance and BBB permeability were evaluated in aged mice using in vivo two-photon imaging. The mice performed voluntary wheel running exercise and their water-maze cognition was assessed; the expression of the astrocytic water channel aquaporin 4 (AQP4), astrocyte and microglial activation, and the accumulation of amyloid beta (Aβ) were evaluated with immunofluorescence or an enzyme-linked immunosorbent assay (ELISA); synaptic function was investigated with Thy1 -green fluorescent protein (GFP) transgenic mice and immunofluorescent staining. Voluntary wheel running significantly improved water-maze cognition in the aged mice, accelerated the efficiency of glymphatic clearance, but which did not affect BBB permeability. The numbers of activated astrocytes and microglia decreased, AQP4 expression increased, and the distribution of astrocytic AQP4 was rearranged. Aβ accumulation decreased, whereas dendrites, dendritic spines and postsynaptic density protein (PSD95) increased. Our study suggests that voluntary wheel running accelerated glymphatic clearance but not BBB permeation, improved astrocytic AQP4 expression and polarization, attenuated the accumulation of amyloid plaques and neuroinflammation, and ultimately protected mice against synaptic dysfunction and a decline in spatial cognition. These data suggest

Voluntary Exercise Promotes Glymphatic Clearance of Amyloid Beta and Reduces the Activation of Astrocytes and Microglia in Aged Mice

Directory of Open Access Journals (Sweden)

Xiao-fei He

2017-05-01

Full Text Available Age is characterized by chronic inflammation, leading to synaptic dysfunction and dementia because the clearance of protein waste is reduced. The clearance of proteins depends partly on the permeation of the blood–brain barrier (BBB or on the exchange of water and soluble contents between the cerebrospinal fluid (CSF and the interstitial fluid (ISF. A wealth of evidence indicates that physical exercise improves memory and cognition in neurodegenerative diseases during aging, such as Alzheimer’s disease (AD, but the influence of physical training on glymphatic clearance, BBB permeability and neuroinflammation remains unclear. In this study, glymphatic clearance and BBB permeability were evaluated in aged mice using in vivo two-photon imaging. The mice performed voluntary wheel running exercise and their water-maze cognition was assessed; the expression of the astrocytic water channel aquaporin 4 (AQP4, astrocyte and microglial activation, and the accumulation of amyloid beta (Aβ were evaluated with immunofluorescence or an enzyme-linked immunosorbent assay (ELISA; synaptic function was investigated with Thy1–green fluorescent protein (GFP transgenic mice and immunofluorescent staining. Voluntary wheel running significantly improved water-maze cognition in the aged mice, accelerated the efficiency of glymphatic clearance, but which did not affect BBB permeability. The numbers of activated astrocytes and microglia decreased, AQP4 expression increased, and the distribution of astrocytic AQP4 was rearranged. Aβ accumulation decreased, whereas dendrites, dendritic spines and postsynaptic density protein (PSD95 increased. Our study suggests that voluntary wheel running accelerated glymphatic clearance but not BBB permeation, improved astrocytic AQP4 expression and polarization, attenuated the accumulation of amyloid plaques and neuroinflammation, and ultimately protected mice against synaptic dysfunction and a decline in spatial cognition

In Vivo TLR9 Inhibition Attenuates CpG-Induced Myocardial Dysfunction

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O. Boehm

2013-01-01

Full Text Available The involvement of toll-like receptor 9 (TLR9, a receptor for bacterial DNA, in septic cardiac depression has not been clarified in vivo. Thus, the aim of the study was to test possible TLR9 inhibitors (H154-thioate, IRS954-thioate, and chloroquine for their ability to protect the cardiovascular system in a murine model of CpG oligodeoxynucleotide- (ODN- dependent systemic inflammation. Sepsis was induced by i.p. application of the TLR9 agonist 1668-thioate in C57BL/6 wild type (WT and TLR9-deficient (TLR9-D mice. Thirty minutes after stimulation TLR9 antagonists were applied i.v. Survival was monitored up to 18 h after stimulation. Cardiac mRNA expression of inflammatory mediators was analyzed 2 h and 6 h after stimulation with 1668-thioate and hemodynamic parameters were monitored at the later time point. Stimulation with 1668-thioate induced a severe sepsis-like state with significant drop of body temperature and significantly increased mortality in WT animals. Additionally, there was a time-dependent increase of inflammatory mediators in the heart accompanied by development of septic heart failure. These effects were not observed in TLR9-D mice. Inhibition of TLR9 by the suppressive ODN H154-thioate significantly ameliorated cardiac inflammation, preserved cardiac function, and improved survival. This suppressive ODN was the most efficient inhibitor of the tested substances.

Increased Expression of Laminin Subunit Alpha 1 Chain by dCas9-VP160

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Arnaud Perrin

2017-03-01

Full Text Available Laminin-111 protein complex links the extracellular matrix to integrin α7β1 in sarcolemma, thus replacing in dystrophic muscles links normally insured by the dystrophin complex. Laminin-111 injection in mdx mouse stabilized sarcolemma, restored serum creatine kinase to wild-type levels, and protected muscles from exercised-induced damages. These results suggested that increased laminin-111 is a potential therapy for DMD. Laminin subunit beta 1 and laminin subunit gamma 1 are expressed in adult human muscle, but laminin subunit alpha 1 (LAMA1 gene is expressed only during embryogenesis. We thus developed an alternative method to laminin-111 protein repeated administration by inducing expression of the endogenous mouse Lama1 gene. This was done with the CRSPR/Cas9 system, i.e., by targeting the Lama1 promoter with one or several gRNAs and a dCas9 coupled with the VP160 transcription activation domain. Lama1 mRNA (qRT-PCR and proteins (immunohistochemistry and western blot were not detected in the control C2C12 myoblasts and in control muscles. However, significant expression was observed in cells transfected and in mouse muscles electroporated with plasmids coding for dCas9-VP160 and a gRNA. Larger synergic increases were observed by using two or three gRNAs. The increased Lama1 expression did not modify the expression of the α7 and β1 integrins. Increased expression of Lama1 by the CRISPR/Cas9 system will have to be further investigated by systemic delivery of the CRISPR/Cas9 components to verify whether this could be a treatment for several myopathies.

Increased opioid dependence in a mouse model of panic disorder

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Xavier Gallego

2010-02-01

Full Text Available Panic disorder is a highly prevalent neuropsychiatric disorder that shows co-occurrence with substance abuse. Here, we demonstrate that TrkC, the high affinity receptor for neurotrophin-3, is a key molecule involved in panic disorder and opiate dependence, using a transgenic mouse model (TgNTRK3. Constitutive TrkC overexpression in TgNTRK3 mice dramatically alters spontaneous firing rates of locus coeruleus neurons and the response of the noradrenergic system to chronic opiate exposure, possibly related to the altered regulation of neurotrophic peptides observed. Notably, TgNTRK3 locus coeruleus neurons showed an increased firing rate in saline-treated conditions and profound abnormalities in their response to met5-enkephalin. Behaviorally, chronic morphine administration induced a significantly increased withdrawal syndrome in TgNTRK3 mice. In conclusion, we show here that the NT-3/TrkC system is an important regulator of neuronal firing in locus coeruleus and could contribute to the adaptations of the noradrenergic system in response to chronic opiate exposure. Moreover, our results indicate that TrkC is involved in the molecular and cellular changes in noradrenergic neurons underlying both panic attacks and opiate dependence and support a functional endogenous opioid deficit in panic disorder patients.

Pressure dependence of resistivity and magnetic properties in a Mn1.9Cr0.1Sb alloy

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D. V. Maheswar Repaka

2017-12-01

Full Text Available We report magnetic-field and hydrostatic pressure dependent electrical resistivity and magnetic properties of a Mn1.9Cr0.1Sb alloy. Upon cooling, the magnetization of Mn1.9Cr0.1Sb exhibits a first-order ferrimagnetic to antiferromagnetic transition at the exchange inversion temperature, TS = 261 K under a 0.1 T magnetic field. Our experimental results show that TS decreases with increasing magnetic field but increase with increasing hydrostatic pressure. The pressure induced transition is accompanied by a large positive baro-resistance of 30.5% for a hydrostatic pressure change of 0.69 GPa. These results show that the lattice parameters as well as the bond distance between Mn-Mn atoms play a crucial role in the magnetic and electronic transport properties of Mn1.9Cr0.1Sb. This sample also exhibits a large inverse magnetocaloric effect with a magnetic entropy change of ΔSm = +6.75 J/kg.K and negative magnetoresistance (44.5% for a field change of 5 T at TS in ambient pressure which may be useful for magnetic cooling and spintronics applications.

The canonical Wnt signaling pathway promotes chondrocyte differentiation in a Sox9-dependent manner

International Nuclear Information System (INIS)

Yano, Fumiko; Kugimiya, Fumitaka; Ohba, Shinsuke; Ikeda, Toshiyuki; Chikuda, Hirotaka; Ogasawara, Toru; Ogata, Naoshi; Takato, Tsuyoshi; Nakamura, Kozo; Kawaguchi, Hiroshi; Chung, Ung-il

2005-01-01

To better understand the role of the canonical Wnt signaling pathway in cartilage development, we adenovirally expressed a constitutively active (Canada) or a dominant negative (dn) form of lymphoid enhancer factor-1 (LEF-1), the main nuclear effector of the pathway, in undifferentiated mesenchymal cells, chondrogenic cells, and primary chondrocytes, and examined the expression of markers for chondrogenic differentiation and hypertrophy. caLEF-1 and LiCl, an activator of the canonical pathway, promoted both chondrogenic differentiation and hypertrophy, whereas dnLEF-1 and the gene silencing of β-catenin suppressed LiCl-promoted effects. To investigate whether these effects were dependent on Sox9, a master regulator of cartilage development, we stimulated Sox9-deficient ES cells with the pathway. caLEF-1 and LiCl promoted both chondrogenic differentiation and hypertrophy in wild-type, but not in Sox9-deficient, cells. The response of Sox9-deficient cells was restored by the adenoviral expression of Sox9. Thus, the canonical Wnt signaling pathway promotes chondrocyte differentiation in a Sox9-dependent manner

Oracle announces increased uptake of Oracle9i Application Server

CERN Multimedia

2002-01-01

Oracle Europe this week announced that increasingly, companies in the region are selecting the Oracle9i Application Server (Oracle9iAS) to develop and deploy web-based business application. CERN is one of its customers (1/2 page).

Xanthene derivatives increase glucose utilization through activation of LKB1-dependent AMP-activated protein kinase.

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Yonghoon Kwon

Full Text Available 5' AMP-activated protein kinase (AMPK is a highly conserved serine-threonine kinase that regulates energy expenditure by activating catabolic metabolism and suppressing anabolic pathways to increase cellular energy levels. Therefore AMPK activators are considered to be drug targets for treatment of metabolic diseases such as diabetes mellitus. To identify novel AMPK activators, we screened xanthene derivatives. We determined that the AMPK activators 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-nitro-phenyl-thioureido]-ethyl}-amide (Xn and 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-cyano-phenyl-thioureido]-ethyl}-amide (Xc elevated glucose uptake in L6 myotubes by stimulating translocation of glucose transporter type 4 (GLUT4. Treatment with the chemical AMPK inhibitor compound C and infection with dominant-negative AMPKa2-virus inhibited AMPK phosphorylation and glucose uptake in myotubes induced by either Xn or Xc. Of the two major upstream kinases of AMPK, we found that Xn and Xc showed LKB1 dependency by knockdown of STK11, an ortholog of human LKB1. Single intravenous administration of Xn and Xc to high-fat diet-induced diabetic mice stimulated AMPK phosphorylation of skeletal muscle and improved glucose tolerance. Taken together, these results suggest that Xn and Xc regulate glucose homeostasis through LKB1-dependent AMPK activation and that the compounds are potential candidate drugs for the treatment of type 2 diabetes mellitus.

Poly(GR) in C9ORF72-Related ALS/FTD Compromises Mitochondrial Function and Increases Oxidative Stress and DNA Damage in iPSC-Derived Motor Neurons.

Science.gov (United States)

Lopez-Gonzalez, Rodrigo; Lu, Yubing; Gendron, Tania F; Karydas, Anna; Tran, Helene; Yang, Dejun; Petrucelli, Leonard; Miller, Bruce L; Almeida, Sandra; Gao, Fen-Biao

2016-10-19

GGGGCC repeat expansions in C9ORF72 are the most common genetic cause of both ALS and FTD. To uncover underlying pathogenic mechanisms, we found that DNA damage was greater, in an age-dependent manner, in motor neurons differentiated from iPSCs of multiple C9ORF72 patients than control neurons. Ectopic expression of the dipeptide repeat (DPR) protein (GR) 80 in iPSC-derived control neurons increased DNA damage, suggesting poly(GR) contributes to DNA damage in aged C9ORF72 neurons. Oxidative stress was also increased in C9ORF72 neurons in an age-dependent manner. Pharmacological or genetic reduction of oxidative stress partially rescued DNA damage in C9ORF72 neurons and control neurons expressing (GR) 80 or (GR) 80 -induced cellular toxicity in flies. Moreover, interactome analysis revealed that (GR) 80 preferentially bound to mitochondrial ribosomal proteins and caused mitochondrial dysfunction. Thus, poly(GR) in C9ORF72 neurons compromises mitochondrial function and causes DNA damage in part by increasing oxidative stress, revealing another pathogenic mechanism in C9ORF72-related ALS and FTD. Copyright © 2016 Elsevier Inc. All rights reserved.

Aquaporin 2 promotes cell migration and epithelial morphogenesis.

Science.gov (United States)

Chen, Ying; Rice, William; Gu, Zhizhan; Li, Jian; Huang, Jianmin; Brenner, Michael B; Van Hoek, Alfred; Xiong, Jianping; Gundersen, Gregg G; Norman, Jim C; Hsu, Victor W; Fenton, Robert A; Brown, Dennis; Lu, Hua A Jenny

2012-09-01

The aquaporin 2 (AQP2) water channel, expressed in kidney collecting ducts, contributes critically to water homeostasis in mammals. Animals lacking or having significantly reduced levels of AQP2, however, have not only urinary concentrating abnormalities but also renal tubular defects that lead to neonatal mortality from renal failure. Here, we show that AQP2 is not only a water channel but also an integrin-binding membrane protein that promotes cell migration and epithelial morphogenesis. AQP2 expression modulates the trafficking and internalization of integrin β1, facilitating its turnover at focal adhesions. In vitro, disturbing the interaction between AQP2 and integrin β1 by mutating the RGD motif led to reduced endocytosis, retention of integrin β1 at the cell surface, and defective cell migration and tubulogenesis. Similarly, in vivo, AQP2-null mice exhibited significant retention of integrin β1 at the basolateral membrane and had tubular abnormalities. In summary, these data suggest that the water channel AQP2 interacts with integrins to promote renal epithelial cell migration, contributing to the structural and functional integrity of the mammalian kidney.

Aquaporin 0 plays a pivotal role in refractive index gradient development in mammalian eye lens to prevent spherical aberration

Energy Technology Data Exchange (ETDEWEB)

Kumari, S. Sindhu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, New York, NY (United States)

2014-10-03

. Transmission and scanning electron micrographs of lenses of both mouse models showed increased extracellular space between fiber cells. Water content determination study showed increase in water in the lenses of these mouse models. In summary, lens transparency, CTCA and compact packing of fiber cells were affected due to the loss of 50% AQP0 leading to larger extracellular space, more water content and SA, possibly due to alteration in RING. To our knowledge, this is the first report identifying the role of AQP0 in RING development to ward off lens SA during focusing.

Both oophorectomy and obesity impaired solely hippocampal-dependent memory via increased hippocampal dysfunction.

Science.gov (United States)

Mantor, Duangkamol; Pratchayasakul, Wasana; Minta, Wanitchaya; Sutham, Wissuta; Palee, Siripong; Sripetchwandee, Jirapas; Kerdphoo, Sasiwan; Jaiwongkum, Thidarat; Sriwichaiin, Sirawit; Krintratun, Warunsorn; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2018-04-17

Our previous study demonstrated that obesity aggravated peripheral insulin resistance and brain dysfunction in the ovariectomized condition. Conversely, the effect of obesity followed by oophorectomy on brain oxidative stress, brain apoptosis, synaptic function and cognitive function, particularly in hippocampal-dependent and hippocampal-independent memory, has not been investigated. Our hypothesis was that oophorectomy aggravated metabolic impairment, brain dysfunction and cognitive impairment in obese rats. Thirty-two female rats were fed with either a normal diet (ND, n = 16) or a high-fat diet (HFD, n = 16) for a total of 20 weeks. At week 13, rats in each group were subdivided into sham and ovariectomized subgroups (n = 8/subgroup). At week 20, all rats were tested for hippocampal-dependent and hippocampal-independent memory by using Morris water maze test (MWM) and Novel objective recognition (NOR) tests, respectively. We found that the obese-insulin resistant condition occurred in sham-HFD-fed rats (HFS), ovariectomized-ND-fed rats (NDO), and ovariectomized-HFD-fed rats (HFO). Increased hippocampal oxidative stress level, increased hippocampal apoptosis, increased hippocampal synaptic dysfunction, decreased hippocampal estrogen level and impaired hippocampal-dependent memory were observed in HFS, NDO, and HFO rats. However, the hippocampal-independent memory, cortical estrogen levels, cortical ROS production, and cortical apoptosis showed no significant difference between groups. These findings suggested that oophorectomy and obesity exclusively impaired hippocampal-dependent memory, possibly via increased hippocampal dysfunction. Nonetheless, oophorectomy did not aggravate these deleterious effects under conditions of obesity. Copyright © 2017. Published by Elsevier Inc.

Combination of secretin and fluvastatin ameliorates the polyuria associated with X-linked nephrogenic diabetes insipidus in mice.

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Procino, Giuseppe; Milano, Serena; Carmosino, Monica; Barbieri, Claudia; Nicoletti, Maria C; Li, Jian H; Wess, Jürgen; Svelto, Maria

2014-07-01

X-linked nephrogenic diabetes insipidus (X-NDI) is a disease caused by inactivating mutations of the vasopressin (AVP) type 2 receptor (V2R) gene. Loss of V2R function prevents plasma membrane expression of the AQP2 water channel in the kidney collecting duct cells and impairs the kidney concentration ability. In an attempt to develop strategies to bypass V2R signaling in X-NDI, we evaluated the effects of secretin and fluvastatin, either alone or in combination, on kidney function in a mouse model of X-NDI. The secretin receptor was found to be functionally expressed in the kidney collecting duct cells. Based on this, X-NDI mice were infused with secretin for 14 days but urinary parameters were not altered by the infusion. Interestingly, secretin significantly increased AQP2 levels in the collecting duct but the protein primarily accumulated in the cytosol. Since we previously reported that fluvastatin treatment increased AQP2 plasma membrane expression in wild-type mice, secretin-infused X-NDI mice received a single injection of fluvastatin. Interestingly, urine production by X-NDI mice treated with secretin plus fluvastatin was reduced by nearly 90% and the urine osmolality was doubled. Immunostaining showed that secretin increased intracellular stores of AQP2 and the addition of fluvastatin promoted AQP2 trafficking to the plasma membrane. Taken together, these findings open new perspectives for the pharmacological treatment of X-NDI.

Genome-wide identification of Jatropha curcas aquaporin genes and the comparative analysis provides insights into the gene family expansion and evolution in Hevea brasiliensis

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Zhi eZou

2016-03-01

Full Text Available Aquaporins (AQPs are channel-forming integral membrane proteins that transport water and other small solutes across biological membranes. Despite the vital role of AQPs, to date, little is known in physic nut (Jatropha curcas L., Euphorbiaceae, an important non-edible oilseed crop with great potential for the production of biodiesel. In this study, 32 AQP genes were identified from the physic nut genome and the family number is relatively small in comparison to 51 in another Euphorbiaceae plant, rubber tree (Hevea brasiliensis Muell. Arg.. Based on the phylogenetic analysis, the JcAQPs were assigned to five subfamilies, i.e., 9 plasma membrane intrinsic proteins (PIPs, 9 tonoplast intrinsic proteins (TIPs, 8 NOD26-like intrinsic proteins (NIPs, 2 X intrinsic proteins (XIPs and 4 small basic intrinsic proteins (SIPs. Like rubber tree and other plant species, functional prediction based on the aromatic/arginine selectivity filter, Froger’s positions and specificity-determining positions showed a remarkable difference in substrate specificity among subfamilies of JcAQPs. Genome-wide comparative analysis revealed the specific expansion of PIP and TIP subfamilies in rubber tree and the specific gene loss of the XIP subfamily in physic nut. Furthermore, by analyzing deep transcriptome sequencing data, the expression evolution especially the expression divergence of duplicated HbAQP genes was also investigated and discussed. Results obtained from this study not only provide valuable information for future functional analysis and utilization of Jc/HbAQP genes, but also provide a useful reference to survey the gene family expansion and evolution in Euphorbiaceae plants and other plant species.

The 'selfish brain' is regulated by aquaporins and autophagy under nutrient deprivation.

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Ye, Qiao; Wu, Yonghong; Gao, Yan; Li, Zhihui; Li, Weiguang; Zhang, Chenggang

2016-05-01

The brain maintains its mass and physiological functional capacity compared with other organs under harsh conditions such as starvation, a mechanism termed the 'selfish brain' theory. To further investigate this phenomenon, mice were examined following water and/or food deprivation. Although the body weights of the mice, the weight of the organs except the brain and blood glucose levels were significantly reduced in the absence of water and/or food, the brain weight maintained its original state. Furthermore, no significant differences in the water content of the brain or its energy balance were observed when the mice were subjected to water and/or food deprivation. To further investigate the mechanism underlying the brain maintenance of water and substance homeostasis, the expression levels of aquaporins (AQPs) and autophagy‑specific protein long‑chain protein 3 (LC3) were examined. During the process of water and food deprivation, no significant differences in the transcriptional levels of AQPs were observed. However, autophagy activity levels were initially stimulated, then suppressed in a time‑dependent manner. LC3 and AQPs have important roles for the survival of the brain under conditions of food and water deprivation, which provided further understanding of the mechanism underlying the 'selfish brain' phenomenon. Although not involved in the energy regulation of the 'selfish brain', AQPs were observed to have important roles in water and food deprivation, specifically with regards to the control of water content. Additionally, the brain exhibits an 'unselfish strategy' using autophagy during water and/or food deprivation. The present study furthered current understanding of the 'selfish brain' theory, and identified additional regulating target genes of AQPs and autophagy, with the aim of providing a basis for the prevention of nutrient shortage in humans and animals.

Basolateral cholesterol depletion alters Aquaporin-2 post-translational modifications and disrupts apical plasma membrane targeting.

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Moeller, Hanne B; Fuglsang, Cecilia Hvitfeldt; Pedersen, Cecilie Nøhr; Fenton, Robert A

2018-01-01

Apical plasma membrane accumulation of the water channel Aquaporin-2 (AQP2) in kidney collecting duct principal cells is critical for body water homeostasis. Posttranslational modification (PTM) of AQP2 is important for regulating AQP2 trafficking. The aim of this study was to determine the role of cholesterol in regulation of AQP2 PTM and in apical plasma membrane targeting of AQP2. Cholesterol depletion from the basolateral plasma membrane of a collecting duct cell line (mpkCCD14) using methyl-beta-cyclodextrin (MBCD) increased AQP2 ubiquitylation. Forskolin, cAMP or dDAVP-mediated AQP2 phosphorylation at Ser269 (pS269-AQP2) was prevented by cholesterol depletion from the basolateral membrane. None of these effects on pS269-AQP2 were observed when cholesterol was depleted from the apical side of cells, or when MBCD was applied subsequent to dDAVP stimulation. Basolateral, but not apical, MBCD application prevented cAMP-induced apical plasma membrane accumulation of AQP2. These studies indicate that manipulation of the cholesterol content of the basolateral plasma membrane interferes with AQP2 PTM and subsequently regulated apical plasma membrane targeting of AQP2. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of aquaporin 5 overexpression on the Ras signaling pathway

International Nuclear Information System (INIS)

Woo, Janghee; Lee, Juna; Kim, Myoung Sook; Jang, Se Jin; Sidransky, David; Moon, Chulso

2008-01-01

Human aquaporin 5 (AQP5) has been shown to be overexpressed in multiple cancers, such as pancreatic cancer and colon cancer. Furthermore, it has been reported that ectopic expression of AQP5 leads to many phenotypic changes characteristic of transformation. However, the biochemical mechanism leading to transformation in AQP5-overexpressing cells has not been clearly elucidated. In this report, the overexpression of AQP5 in NIH3T3 cells demonstrated a significant effect on Ras activity and, thus, cell proliferation. Furthermore, this influence was shown to be mediated by phosphorylation of the PKA consensus site of AQP5. This is the first evidence demonstrating an association between AQP5 and a signaling pathway, namely the Ras signal transduction pathway, which may be the basis of the oncogenic properties seen in AQP-overexpressing cells

Aquaporins 6-12 in the human eye

DEFF Research Database (Denmark)

Tran, Thuy Linh; Bek, Toke; Holm, Lars

2012-01-01

Purpose: Aquaporins (AQPs) are widely expressed and have diverse distribution patterns in the eye. AQPs 0-5 have been localized at the cellular level in human eyes. We investigated the presence of the more recently discovered AQPs 6-12 in the human eye. Methods: RT-PCR was performed on fresh tissue...... from two human eyes divided into the cornea, corneal limbus, ciliary body and iris, lens, choroid, optic nerve, retina and sclera. Each structure was examined to detect the mRNA of AQPs 6-12. Twenty-one human eyes were examined using immunohistochemical and immunofluorescence techniques to determine...... was detected in the corneal epithelium, corneal endothelium, trabecular meshwork endothelium, ciliary epithelia, lens epithelium, the inner and outer limiting membrane of the retina, the retinal pigment epithelium and the capillary endothelium of all parts of the eye. AQP9 immunolabelling was detected...

CDK9-dependent RNA polymerase II pausing controls transcription initiation.

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Gressel, Saskia; Schwalb, Björn; Decker, Tim Michael; Qin, Weihua; Leonhardt, Heinrich; Eick, Dirk; Cramer, Patrick

2017-10-10

Gene transcription can be activated by decreasing the duration of RNA polymerase II pausing in the promoter-proximal region, but how this is achieved remains unclear. Here we use a 'multi-omics' approach to demonstrate that the duration of polymerase pausing generally limits the productive frequency of transcription initiation in human cells ('pause-initiation limit'). We further engineer a human cell line to allow for specific and rapid inhibition of the P-TEFb kinase CDK9, which is implicated in polymerase pause release. CDK9 activity decreases the pause duration but also increases the productive initiation frequency. This shows that CDK9 stimulates release of paused polymerase and activates transcription by increasing the number of transcribing polymerases and thus the amount of mRNA synthesized per time. CDK9 activity is also associated with long-range chromatin interactions, suggesting that enhancers can influence the pause-initiation limit to regulate transcription.

Maximal Oxygen Consumption is Reduced in Aquaporin-1 Knockout Mice

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Samer Al-Samir

2016-08-01

Full Text Available We have measured maximal oxygen consumption (V’O2,max of mice lacking one or two of the established mouse red-cell CO2 channels AQP1, AQP9 and Rhag. We intended to study whether these proteins, by acting as channels for O2, determine O2 exchange in the lung and in the periphery. We found that V’O2,max as determined by the Helox technique is reduced by ~ 16%, when AQP1 is knocked out, but not when AQP9 or Rhag are lacking. This figure holds for animals respiring normoxic as well as hypoxic gas mixtures. To see whether the reduction of V’O2,max is due to impaired O2 uptake in the lung, we measured carotid arterial O2 saturation (SO2 by pulse oximetry. Neither under normoxic (inspiratory O2 21% nor under hypoxic conditions (11% O2 is there a difference in SO2 between AQP1null and WT mice, suggesting that AQP1 is not critical for O2 uptake in the lung. The fact that the % reduction of V’O2,max is identical in normoxia and hypoxia indicates moreover that the limitation of V’O2,max is not due to an O2 diffusion problem, neither in the lung nor in the periphery. Instead, it appears likely that AQP1null animals exhibit a reduced V’O2,max due to the reduced wall thickness and muscle mass of the left ventricles of their hearts, as reported previously. We conclude that very likely the properties of the hearts of AQP1 knockout mice cause a reduced maximal cardiac output and thus cause a reduced V’O2,max, which constitutes a new phenotype of these mice.

Increased Expression of Laminin Subunit Alpha 1 Chain by dCas9-VP160.

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Perrin, Arnaud; Rousseau, Joël; Tremblay, Jacques P

2017-03-17

Laminin-111 protein complex links the extracellular matrix to integrin α7β1 in sarcolemma, thus replacing in dystrophic muscles links normally insured by the dystrophin complex. Laminin-111 injection in mdx mouse stabilized sarcolemma, restored serum creatine kinase to wild-type levels, and protected muscles from exercised-induced damages. These results suggested that increased laminin-111 is a potential therapy for DMD. Laminin subunit beta 1 and laminin subunit gamma 1 are expressed in adult human muscle, but laminin subunit alpha 1 (LAMA1) gene is expressed only during embryogenesis. We thus developed an alternative method to laminin-111 protein repeated administration by inducing expression of the endogenous mouse Lama1 gene. This was done with the CRSPR/Cas9 system, i.e., by targeting the Lama1 promoter with one or several gRNAs and a dCas9 coupled with the VP160 transcription activation domain. Lama1 mRNA (qRT-PCR) and proteins (immunohistochemistry and western blot) were not detected in the control C2C12 myoblasts and in control muscles. However, significant expression was observed in cells transfected and in mouse muscles electroporated with plasmids coding for dCas9-VP160 and a gRNA. Larger synergic increases were observed by using two or three gRNAs. The increased Lama1 expression did not modify the expression of the α7 and β1 integrins. Increased expression of Lama1 by the CRISPR/Cas9 system will have to be further investigated by systemic delivery of the CRISPR/Cas9 components to verify whether this could be a treatment for several myopathies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Traditional Chinese medicine, Qing Ying Tang, ameliorates the severity of acute lung injury induced by severe acute pancreatitis in rats via the upregulation of aquaporin-1.

Science.gov (United States)

Gao, Zhenming; Xu, Junfeng; Sun, Deguang; Zhang, Rixin; Liang, Rui; Wang, Liming; Fan, Rong

2014-12-01

Aquaporin-1 (AQP-1) is expressed in lung endothelial cells and regulates water transport; thus, AQP-1 plays an important role in a number of edema-associated lung diseases. Qing Yin Tang (QYT), a traditional Chinese medicine, has been shown to effectively reduce the mortality rate of acute lung injury (ALI) induced by severe acute pancreatitis (SAP). The current study aimed to investigate the detailed mechanisms underlying the effects of QYT on ALI induced by SAP, particularly the effects on the expression levels of AQP-1 in the lung tissue. ALI was established in Wister rats who were subsequently divided into four groups: SHAM, ALI, dexamethasone (DEX) and QYT groups (n=8 per group). In the QYT group, 20 ml/kg QYT was administered by gavage immediately following the induction of SAP. Blood and lung tissues were collected 8 h following the induction of pancreatitis. The lung wet/dry ratio, as well as the levels of blood gases, serum amylase and tumor necrosis factor-α (TNF-α), were measured at 4, 8 and 12 h following SAP-associated ALI induction surgery. The expression levels of AQP-1 in the lung tissue were detected by quantitative polymerase chain reaction, immunohistochemistry and western blot analysis. No statistically significant differences were observed with regard to the levels of serum amylase, wet/dry ratio, partial pressure of oxygen, serum TNF-α and pathological changes in the pulmonary tissue between the QYT and DEX groups; however, a statistically significant difference was observed when compared with the ALI group. The expression levels of AQP-1 significantly increased (P<0.05) and lung edema was alleviated in the QYT and DEX groups, when compared with ALI group. Therefore, the expression level of AQP-1 is associated with pulmonary edema. QYT protects the lungs from injury induced by SAP via the upregulation of AQP-1, which suppresses TNF-α expression.

Age-dependent increase in green autofluorescence of blood ...

Indian Academy of Sciences (India)

PRAKASH KUMAR

Protective enzymes against oxidative ... School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India ... provide evidence for an age dependent increase in the GAF of blood erythrocytes that is accentuated by depletion of.

Evaluation of Clinical Interest of Anti-Aquaporin-4 Autoantibody Followup in Neuromyelitis Optica

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Jean-Baptiste Chanson

2013-01-01

Full Text Available Neuromyelitis optica (NMO is an autoimmune disease in which a specific biomarker named NMO-IgG and directed against aquaporin-4 (AQP4 has been found. A correlation between disease activity and anti-AQP4 antibody (Ab serum concentration or complement-mediated cytotoxicity has been reported, but the usefulness of longitudinal evaluation of these parameters remains to be evaluated in actual clinical practice. Thirty serum samples from 10 NMO patients positive for NMO-IgG were collected from 2006 to 2011. Anti-AQP4 Ab serum concentration and complement-mediated cytotoxicity were measured by flow cytometry using two quantitative cell-based assays (CBA and compared with clinical parameters. We found a strong correlation between serum anti-AQP4 Ab concentration and complement-mediated cytotoxicity (P<0.0001. Nevertheless, neither relapse nor worsening of impairment level was closely associated with a significant increase in serum Ab concentration or cytotoxicity. These results suggest that complement-mediated serum cytotoxicity assessment does not provide extra insight compared to anti-AQP4 Ab serum concentration. Furthermore, none of these parameters appears closely related to disease activity and/or severity. Therefore, in clinical practice, serum anti-AQP4 reactivity seems not helpful as a predictive biomarker in the followup of NMO patients as a means of predicting the onset of a relapse and adapting the treatment accordingly.

The Role of Aquaporins in Ocular Lens Homeostasis

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Schey, Kevin L.; Petrova, Rosica S.; Gletten, Romell B.; Donaldson, Paul J.

2017-01-01

Aquaporins (AQPs), by playing essential roles in the maintenance of ocular lens homeostasis, contribute to the establishment and maintenance of the overall optical properties of the lens over many decades of life. Three aquaporins, AQP0, AQP1 and AQP5, each with distinctly different functional properties, are abundantly and differentially expressed in the different regions of the ocular lens. Furthermore, the diversity of AQP functionality is increased in the absence of protein turnover by age-related modifications to lens AQPs that are proposed to alter AQP function in the different regions of the lens. These regional differences in AQP functionality are proposed to contribute to the generation and directionality of the lens internal microcirculation; a system of circulating ionic and fluid fluxes that delivers nutrients to and removes wastes from the lens faster than could be achieved by passive diffusion alone. In this review, we present how regional differences in lens AQP isoforms potentially contribute to this microcirculation system by highlighting current areas of investigation and emphasizing areas where future work is required. PMID:29231874

Targeting aquaporin function: potent inhibition of aquaglyceroporin-3 by a gold-based compound.

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Ana Paula Martins

Full Text Available Aquaporins (AQPs are membrane channels that conduct water and small solutes such as glycerol and are involved in many physiological functions. Aquaporin-based modulator drugs are predicted to be of broad potential utility in the treatment of several diseases. Until today few AQP inhibitors have been described as suitable candidates for clinical development. Here we report on the potent inhibition of AQP3 channels by gold(III complexes screened on human red blood cells (hRBC and AQP3-transfected PC12 cells by a stopped-flow method. Among the various metal compounds tested, Auphen is the most active on AQP3 (IC(50 = 0.8±0.08 µM in hRBC. Interestingly, the compound poorly affects the water permeability of AQP1. The mechanism of gold inhibition is related to the ability of Au(III to interact with sulphydryls groups of proteins such as the thiolates of cysteine residues. Additional DFT and modeling studies on possible gold compound/AQP adducts provide a tentative description of the system at a molecular level. The mapping of the periplasmic surface of an homology model of human AQP3 evidenced the thiol group of Cys40 as a likely candidate for binding to gold(III complexes. Moreover, the investigation of non-covalent binding of Au complexes by docking approaches revealed their preferential binding to AQP3 with respect to AQP1. The high selectivity and low concentration dependent inhibitory effect of Auphen (in the nanomolar range together with its high water solubility makes the compound a suitable drug lead for future in vivo studies. These results may present novel metal-based scaffolds for AQP drug development.

Characterization of protein phosphatase 2A acting on phosphorylated plasma membrane aquaporin of tulip petals.

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Azad, Abul Kalam; Sawa, Yoshihiro; Ishikawa, Takahiro; Shibata, Hitoshi

2004-05-01

A protein phosphatase holo-type enzyme (38, 65, and 75 kDa) preparation and a free catalytic subunit (38 kDa) purified from tulip petals were characterized as protein phosphatase 2A (PP2A) by immunological and biochemical approaches. The plasma membrane containing the putative plasma membrane aquaporin (PM-AQP) was prepared from tulip petals, phosphorylated in vitro, and used as the substrate for both of the purified PP2A preparations. Although both preparations dephosphorylated the phosphorylated PM-AQP at 20 degrees C, only the holo-type enzyme preparation acted at 5 degrees C on the phosphorylated PM-AQP with higher substrate specificity, suggesting that regulatory subunits are required for low temperature-dependent dephosphorylation of PM-AQP in tulip petals.

Linkage between increased nociception and olfaction via a SCN9A haplotype.

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Dirk Heimann

Full Text Available BACKGROUND AND AIMS: Mutations reducing the function of Nav1.7 sodium channels entail diminished pain perception and olfactory acuity, suggesting a link between nociception and olfaction at ion channel level. We hypothesized that if such link exists, it should work in both directions and gain-of-function Nav1.7 mutations known to be associated with increased pain perception should also increase olfactory acuity. METHODS: SCN9A variants were assessed known to enhance pain perception and found more frequently in the average population. Specifically, carriers of SCN9A variants rs41268673C>A (P610T; n = 14 or rs6746030C>T (R1150W; n = 21 were compared with non-carriers (n = 40. Olfactory function was quantified by assessing odor threshold, odor discrimination and odor identification using an established olfactory test. Nociception was assessed by measuring pain thresholds to experimental nociceptive stimuli (punctate and blunt mechanical pressure, heat and electrical stimuli. RESULTS: The number of carried alleles of the non-mutated SCN9A haplotype rs41268673C/rs6746030C was significantly associated with the comparatively highest olfactory threshold (0 alleles: threshold at phenylethylethanol dilution step 12 of 16 (n = 1, 1 allele: 10.6±2.6 (n = 34, 2 alleles: 9.5±2.1 (n = 40. The same SCN9A haplotype determined the pain threshold to blunt pressure stimuli (0 alleles: 21.1 N/m(2, 1 allele: 29.8±10.4 N/m(2, 2 alleles: 33.5±10.2 N/m(2. CONCLUSIONS: The findings established a working link between nociception and olfaction via Nav1.7 in the gain-of-function direction. Hence, together with the known reduced olfaction and pain in loss-of-function mutations, a bidirectional genetic functional association between nociception and olfaction exists at Nav1.7 level.

Expression, localization and possible functions of aquaporins 3 and 8 in rat digestive system.

Science.gov (United States)

Zhao, G X; Dong, P P; Peng, R; Li, J; Zhang, D Y; Wang, J Y; Shen, X Z; Dong, L; Sun, J Y

2016-01-01

Although aquaporins (AQPs) play important roles in transcellular water movement, their precise quantification and localization remains controversial. We investigated expression levels and localizations of AQP3 and AQP8 and their possible functions in the rat digestive system using real-time polymerase chain reactions, western blot analysis and immunohistochemistry. We investigated the expression levels and localizations of AQP3 and AQP8 in esophagus, forestomach, glandular stomach, duodenum, jejunum, ileum, proximal and distal colon, and liver. AQP3 was expressed in the basolateral membranes of stratified epithelia (esophagus and forestomach) and simple columnar epithelia (glandular stomach, ileum, and proximal and distal colon). Expression was particularly abundant in the esophagus, and proximal and distal colon. AQP8 was found in the subapical compartment of columnar epithelial cells of the jejunum, ileum, proximal colon and liver; the most intense staining occurred in the jejunum. Our results suggest that AQP3 and AQP8 play significant roles in intestinal function and/or fluid homeostasis and may be an important subject for future investigation of disorders that involve disruption of intestinal fluid homeostasis, such as inflammatory bowel disease and irritable bowel syndrome.

Acetazolamide Mitigates Astrocyte Cellular Edema Following Mild Traumatic Brain Injury

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Sturdivant, Nasya M.; Smith, Sean G.; Ali, Syed F.; Wolchok, Jeffrey C.; Balachandran, Kartik

2016-09-01

Non-penetrating or mild traumatic brain injury (mTBI) is commonly experienced in accidents, the battlefield and in full-contact sports. Astrocyte cellular edema is one of the major factors that leads to high morbidity post-mTBI. Various studies have reported an upregulation of aquaporin-4 (AQP4), a water channel protein, following brain injury. AZA is an antiepileptic drug that has been shown to inhibit AQP4 expression and in this study we investigate the drug as a therapeutic to mitigate the extent of mTBI induced cellular edema. We hypothesized that mTBI-mediated astrocyte dysfunction, initiated by increased intracellular volume, could be reduced when treated with AZA. We tested our hypothesis in a three-dimensional in vitro astrocyte model of mTBI. Samples were subject to no stretch (control) or one high-speed stretch (mTBI) injury. AQP4 expression was significantly increased 24 hours after mTBI. mTBI resulted in a significant increase in the cell swelling within 30 min of mTBI, which was significantly reduced in the presence of AZA. Cell death and expression of S100B was significantly reduced when AZA was added shortly before mTBI stretch. Overall, our data point to occurrence of astrocyte swelling immediately following mTBI, and AZA as a promising treatment to mitigate downstream cellular mortality.

Long-term MRI findings in neuromyelitis optica: seropositive versus seronegative patients.

Science.gov (United States)

Kıyat-Atamer, A; Ekizoğlu, E; Tüzün, E; Kürtüncü, M; Shugaiv, E; Akman-Demir, G; Eraksoy, M

2013-05-01

Neuromyelitis optica (NMO) is a severe demyelinating inflammatory disorder associated with serum antibodies against aquaporin 4 (AQP4-Ab). A significant number of patients with NMO remain seronegative over time. Long-term observational magnetic resonance imaging (MRI) studies of the CNS in patients with NMO are rare or of limited duration. The objective of this study is to determine long-term MRI characteristics of seropositive and seronegative patients, and assess possible overlap with multiple sclerosis (MS). Clinical and radiological characteristics of 28 patients with NMO at onset and of 17 patients after an average follow-up time of 9 years were recorded. Fifty percent of patients were seropositive for AQP4-Ab. Onset and final brain/spinal MRI scans were retrospectively analysed and compared. Significantly more patients in the seronegative group had brain lesions at onset. Spinal lesions of seropositive patients were longer and showed increased cord swelling at onset MRI scans. After the follow-up time the differences between both groups disappeared. Patients in the seropositive group tended to develop brain lesions over time. No patient fulfilled Barkhof's or McDonald's radiological criteria for MS at onset or over time. Brain MRI features show differences between seropositive and seronegative patients at time of onset in NMO, but differences between groups vanish over time. None of the AQP4-negative patients fulfill radiological MS criteria on a long-term basis, suggesting that seronegative NMO constitutes an independent entity. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Did the Affordable Care Act's Dependent Coverage Mandate Increase Premiums?

OpenAIRE

Briggs Depew; James Bailey

2014-01-01

We investigate the impact of the Affordable Care Act's dependent coverage mandate on insurance premiums. The expansion of dependent coverage under the ACA allows young adults to remain on their parent's private health insurance plans until the age of 26. We find that the mandate has led to a 2.5-2.8 percent increase in premiums for health insurance plans that cover children, relative to single-coverage plans. We find no evidence that the mandate caused an increase in the amount of the employe...

Diagnostic significance of tumor markers CEA, CA50 and CA19-9 for colorectal cancer

International Nuclear Information System (INIS)

Chen Yumei; Huang Gang

2005-01-01

Objective: To investigate the expression and diagnostic significance of three serum tumor markers (CEA, CA50, CA19-9) in patients with colorectal cancer, with special emphasis on their combined assay. Methods: Serum CEA, CA19-9 levels (with chemiluminescence immunoassay) and CA50 levels (with immunoradiometric assay) were determined in 94 patients with colorectal cancer, 20 patients with benign colorectal disorders and 37 controls. Results: The expressions of the serum tumor markers were significantly higher in patients with colorectal cancer than those in patients with benign colorectal disorders and controls (P<0.05). There was no significant difference between the levels in the latter two groups. CEA assay had the highest sensitivity (57.4%) and specificity (85.9%). Combined assay of the three could enhance both the sensitivity (62.7%) and specificity (96.5%). The serum levels of the markers were significantly higher in patients with colonic cancer than those in patients with rectal cancer (P<0.05). The levels were positively correlated with the size of the growth and stage of the disease. Serum tumor marker levels were also significantly higher in patients with metastasis (regional/distant) than those in patients without metastasis (P<0.05). Conclusion: Determination of serum CEA, CA50 and CA19-9 levels had definite value for the diagnosis and assessment of the pathology as well as biologic behavior colorectal cancer. Combined assay of the three could enhance the diagnostic sensitivity and specificity. (authors)

Temperature dependence of the magnetostriction in polycrystalline PrFe1.9 and TbFe2 alloys: Experiment and theory

International Nuclear Information System (INIS)

Tang, Y. M.; Chen, L. Y.; Huang, H. F.; Xia, W. B.; Zhang, S. Y.; Wei, J.; Tang, S. L.; Du, Y. W.; Zhang, L.

2014-01-01

A remarkable magnetostriction λ 111 as large as 6700 ppm was found at 70 K in PrFe 1.9 alloy. This value is even larger than the theoretical maximum of 5600 ppm estimated by the Steven's equivalent operator method. The temperature dependence of λ 111 for PrFe 1.9 and TbFe 2 alloys follows well with the single-ion theory rule, which yields giant estimated λ 111 values of about 8000 and 4200 ppm for PrFe 1.9 and TbFe 2 alloys, respectively, at 0 K. The easy magnetization direction of PrFe 1.9 changes from [111] to [100] as temperature decreases, which leads to the abnormal decrease of the magnetostriction λ. The rare earth sublattice moment increases sharply in PrFe 1.9 alloy with decreasing temperature, resulting in the remarkably largest estimated value of λ 111 at 0 K according to the single-ion theory

Acute effects of heroin on emotions in heroin-dependent patients.

Science.gov (United States)

Blum, Julia; Gerber, Hana; Gerhard, Urs; Schmid, Otto; Petitjean, Sylvie; Riecher-Rössler, Anita; Wiesbeck, Gerhard A; Borgwardt, Stefan J; Walter, Marc

2013-01-01

Euphoria has been described in heroin-dependent individuals after heroin administration. However, affective disturbances and disorders are common in heroin dependence. The present study examined the acute effects of heroin on emotions in heroin-dependent patients. This randomized controlled crossover trial included 28 heroin-dependent patients (67.9% male, n = 19) in stable heroin-assisted treatment and 20 healthy controls. The patients were administered heroin or saline (placebo), the controls were administered saline. Data measuring mood, affects and heroin craving (BDI, AMRS, STAI, STAXI, and HCQ) were assessed before and 60 minutes after substance injection. Before substance injection, heroin-dependent patients showed significantly higher levels of anxiety and depression than healthy controls (p emotions, including craving, and a significant increase in emotional well-being (p emotions, once they had received heroin. Heroin dampens craving, negative emotions, and increases positive emotions. These findings indicate that heroin regulates emotions and underscore the clinical benefit of opioid substitution treatment for heroin-dependent patients. Copyright © American Academy of Addiction Psychiatry.

Prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma

Science.gov (United States)

Wang, Wei; Chen, Xiao-Long; Zhao, Shen-Yu; Xu, Yu-Hui; Zhang, Wei-Han; Liu, Kai; Chen, Xin-Zu; Yang, Kun; Zhang, Bo; Chen, Zhi-Xin; Chen, Jia-Ping; Zhou, Zong-Guang; Hu, Jian-Kun

2016-01-01

The prognostic significance of preoperative serum CA125, CA19-9 and CEA in gastric carcinoma (GC) has been widely reported and is still under debate. Here, we evaluated the prognostic significance of preoperative serum CA125, CA19-9 and CEA in patients with GC. 1692 patients with GC who underwent gastrectomy were divided into the training (from January 2005 to December 2011, n = 1024) and the validation (from January 2012 to December 2013, n = 668) cohorts. Positive groups of CA125 (> 13.72 U/ml), CA19-9 (> 23.36 U/ml) and CEA (> 4.28 ng/ml) were significantly associated with more advanced clinicopathological traits and worse outcomes than that of negative groups (all P tumor size (P tumor markers (NPTM) were more accurate in prognostic prediction than TNM stage alone. Our findings suggested that elevated preoperative serum CA125, CA19-9 and CEA were associated with more advanced clinicopathological traits and less favorable outcomes. In addition, CA125 as an independent prognostic factor should be further investigated. Nomogram based on NPTM could accurately predict the prognosis of GC patients. PMID:27097114

Mechanism of depression as a risk factor in the development of Alzheimer's disease: the function of AQP4 and the glymphatic system.

Science.gov (United States)

Xia, Maosheng; Yang, Li; Sun, Guangfeng; Qi, Shuang; Li, Baoman

2017-02-01

Many studies have indicated that a history of depression increases the risk of developing Alzheimer's disease (AD); however, the potential pathogenestic mechanism by which depression functions as a high risk factor for AD remains unknown. Recently, a "cerebral lymphatic system" referred to as "glymphatic system" has been demonstrated to be responsible for neuronal extracellular waste protein clearance via a paravascular pathway. However, the function of glymphatic pathway has not been determined in depressive disorders. The present study used an animal model of chronic unpredictable mild stress (CUMS) to determine the function of glymphatic pathway by using fluorescence tracers. Immunohistochemistry was used to assess the accumulation of endogenous mouse and exogenous human amyloid beta 42 (Aβ42) in CUMS-treated mice with or without treatment with antidepressant fluoxetine. Glymphatic pathway circulation was impaired in mice treated with CUMS; moreover, glymphatic pathway dysfunction suppressed Aβ42 metabolism, because the accumulation of endogenous and exogenous Aβ42 was increased in the brains of the CUMS-treated mice. However, treatment with fluoxetine reversed these destructive effects of CUMS on glymphatic system. In anhedonic mice, the expression of the water channel aquaporin 4 (AQP4), a factor in glymphatic pathway dysfunction, was down-regulated in cortex and hippocampus. The dysfunction of glymphatic system suggested why a history of depression may be a strong risk factor for AD in anhedonic mice. We hope our study will contribute to an understanding of the risk mechanism of depressive disorder in the development of AD and the mechanisms of antidepressant therapies in AD.

Cyclin-dependent kinase 9 is a novel specific molecular target in adult T-cell leukemia/lymphoma.

Science.gov (United States)

Narita, Tomoko; Ishida, Takashi; Ito, Asahi; Masaki, Ayako; Kinoshita, Shiori; Suzuki, Susumu; Takino, Hisashi; Yoshida, Takashi; Ri, Masaki; Kusumoto, Shigeru; Komatsu, Hirokazu; Imada, Kazunori; Tanaka, Yuetsu; Takaori-Kondo, Akifumi; Inagaki, Hiroshi; Scholz, Arne; Lienau, Philip; Kuroda, Taruho; Ueda, Ryuzo; Iida, Shinsuke

2017-08-31

Cyclin-dependent kinase 9 (CDK9), a subunit of the positive transcription elongation factor b (P-TEFb) complex, regulates gene transcription elongation by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (RNAPII). The deregulation of CDK9/P-TEFb has important implications for many cancer types. BAY 1143572 is a novel and highly selective CDK9/P-TEFb inhibitor currently being investigated in phase 1 studies. We evaluated the therapeutic potential of BAY 1143572 in adult T-cell leukemia/lymphoma (ATL). As a result of CDK9 inhibition and subsequent inhibition of phosphorylation at serine 2 of the RNAPII CTD, BAY 1143572 decreased c-Myc and Mcl-1 levels in ATL-derived or human T-cell lymphotropic virus type-1 (HTLV-1)-transformed lines and primary ATL cells tested, leading to their growth inhibition and apoptosis. Median inhibitory concentrations for BAY 1143572 in ATL-derived or HTLV-1-transformed lines (n = 8), primary ATL cells (n = 11), and CD4 + cells from healthy volunteers (n = 5) were 0.535, 0.30, and 0.36 μM, respectively. Next, NOG mice were used as recipients of tumor cells from an ATL patient. BAY 1143572-treated ATL-bearing mice (once daily 12.5 mg/kg oral application) demonstrated significantly decreased ATL cell infiltration of the liver and bone marrow, as well as decreased human soluble interleukin-2 receptor levels in serum (reflecting the ATL tumor burden), compared with untreated mice (n = 8 for both). BAY 1143572-treated ATL-bearing mice demonstrated significantly prolonged survival compared with untreated ATL-bearing mice (n = 7 for both). Collectively, this study indicates that BAY 1143572 showed strong potential as a novel treatment of ATL. © 2017 by The American Society of Hematology.

Treatment of neuromyelitis optica: state-of-the-art and emerging therapies

Science.gov (United States)

Papadopoulos, Marios C.; Bennett, Jeffrey L.; Verkman, Alan S.

2014-01-01

Neuromyelitis optica (NMO) is an autoimmune disease of the CNS that is characterized by inflammatory demyelinating lesions in the spinal cord and optic nerve, potentially leading to paralysis and blindness. NMO can usually be distinguished from multiple sclerosis (MS) on the basis of seropositivity for IgG antibodies against the astrocytic water channel aquaporin-4 (AQP4). Differentiation from MS is crucial, because some MS treatments can exacerbate NMO. NMO pathogenesis involves AQP4-IgG antibody binding to astrocytic AQP4, which causes complement-dependent cytotoxicity and secondary inflammation with granulocyte and macrophage infiltration, blood–brain barrier disruption and oligodendrocyte injury. Current NMO treatments include general immunosuppressive agents, B-cell depletion, and plasma exchange. Therapeutic strategies targeting complement proteins, the IL-6 receptor, neutrophils, eosinophils and CD19—all initially developed for other indications—are under clinical evaluation for repurposing for NMO. Therapies in the preclinical phase include AQP4-blocking antibodies and AQP4-IgG enzymatic inactivation. Additional, albeit currently theoretical, treatment options include reduction of AQP4 expression, disruption of AQP4 orthogonal arrays, enhancement of complement inhibitor expression, restoration of the blood–brain barrier, and induction of immune tolerance. Despite the many therapeutic options in NMO, no controlled clinical trials in patients with this condition have been conducted to date. PMID:25112508

Aquaporin-1 and aquaporin-3 expressions in the temporo-mandibular joint condylar cartilage after an experimentally induced osteoarthritis.

Science.gov (United States)

Meng, Juan-hong; Ma, Xu-chen; Li, Zhi-min; Wu, Deng-cheng

2007-12-20

Over 70% of the total tissue weight in the cartilage matrix consists of water, and the early-stage osteoarthritic cartilage is characterized by swelling. Water transport in the cartilage matrix and across the membranes of chondrocytes may be important in normal and pathological conditions of cartilage. The purpose of this study was to identify aquaporin-1 (AQP1) and aquaporin-3 (AQP3) expressions in the mandibular condylar cartilage after experimentally induced osteoarthritis (OA) in rats. An experimental temporomandibular joint OA was induced by partial discectomy in rats. The pathological characteristics of the normal, early-stage, and late-stage osteoarthritic TMJ cartilages were verified by histological techniques. The AQP1 and AQP3 gene expressions in the normal and osteoarthritic cartilages were measured using quantitative real-time reverse-transcription PCR analysis. The cartilage sections were incubated in primary polyclonal antibodies to AQP3; immunofluorescent microscopy was used to examine the AQP3 expression shown by its protein level. The mRNA expression levels of AQP1 and AQP3, analyzed using quantitative PCR, revealed that AQP3 mRNA was highly up-regulated in the OA cartilage, which was considered significant. There was no notable difference in the expression of AQP1 mRNA between OA and normal controls. With the progressing of the OA, the localization of the AQP3 protein was quite different from that of the normal cartilage. Compared to the normal cartilage, the expressions of AQP3 protein were observed mainly in the proliferative zone and the upper mid-zone chondrocytes at the early-stage of OA, and were observed to appear frequently throughout the mid- and deep zone during the late-stage of OA. The high expression of AQP3 mRNA in the OA cartilage and the different localization of the AQP3 protein suggest that it may play a particular role in OA pathogenesis. Further study of AQP3 function may provide new insight into the understanding of the

Targeted deletion of C1q/TNF-related protein 9 increases food intake, decreases insulin sensitivity, and promotes hepatic steatosis in mice.

Science.gov (United States)

Wei, Zhikui; Lei, Xia; Petersen, Pia S; Aja, Susan; Wong, G William

2014-04-01

Transgenic overexpression of CTRP9, a secreted hormone downregulated in obesity, confers striking protection against diet-induced obesity and type 2 diabetes. However, the physiological relevance of this adiponectin-related plasma protein remains undefined. Here, we used gene targeting to establish the metabolic function of CTRP9 in a physiological context. Mice lacking CTRP9 were obese and gained significantly more body weight when fed standard laboratory chow. Increased food intake, due in part to upregulated expression of hypothalamic orexigenic neuropeptides, contributed to greater adiposity in CTRP9 knockout mice. Although the frequency of food intake remained unchanged, CTRP9 knockout mice increased caloric intake by increasing meal size and decreasing satiety ratios. The absence of CTRP9 also resulted in peripheral tissue insulin resistance, leading to increased fasting insulin levels, impaired hepatic insulin signaling, and reduced insulin tolerance. Increased expression of lipogenic genes, combined with enhanced caloric intake, contributed to hepatic steatosis in CTRP9 knockout mice. Loss of CTRP9 also resulted in reduced skeletal muscle AMPK activation and mitochondrial content. Together, these results provide the genetic evidence for a physiological role of CTRP9 in controlling energy balance via central and peripheral mechanisms.

Araloside C Prevents Hypoxia/Reoxygenation-Induced Endoplasmic Reticulum Stress via Increasing Heat Shock Protein 90 in H9c2 Cardiomyocytes

Directory of Open Access Journals (Sweden)

Yuyang Du

2018-04-01

Full Text Available Araloside C (AsC is a cardioprotective triterpenoid compound that is mainly isolated from Aralia elata. This study aims to determine the effects of AsC on hypoxia-reoxygenation (H/R-induced apoptosis in H9c2 cardiomyocytes and its underlying mechanisms. Results demonstrated that pretreatment with AsC (12.5 μM for 12 h significantly suppressed the H/R injury in H9c2 cardiomyocytes, including improving cell viability, attenuating the LDH leakage and preventing cardiomyocyte apoptosis. AsC also inhibited H/R-induced ER stress by reducing the activation of ER stress pathways (PERK/eIF2α and ATF6, and decreasing the expression of ER stress-related apoptotic proteins (CHOP and caspase-12. Moreover, AsC greatly improved the expression level of HSP90 compared with that in the H/R group. The use of HSP90 inhibitor 17-AAG and HSP90 siRNA blocked the above suppression effect of AsC on ER stress-related apoptosis caused by H/R. Taken together, AsC could reduce H/R-induced apoptosis possibly because it attenuates ER stress-dependent apoptotic pathways by increasing HSP90 expression.

Assessing dependency using self-report and indirect measures: examining the significance of discrepancies.

Science.gov (United States)

Cogswell, Alex; Alloy, Lauren B; Karpinski, Andrew; Grant, David A

2010-07-01

The present study addressed convergence between self-report and indirect approaches to assessing dependency. We were moderately successful in validating an implicit measure, which was found to be reliable, orthogonal to 2 self-report instruments, and predictive of external criteria. This study also examined discrepancies between scores on self-report and implicit measures, and has implications for their significance. The possibility that discrepancies themselves are pathological was not supported, although discrepancies were associated with particular personality profiles. Finally, this study offered additional evidence for the relation between dependency and depressive symptomatology and identified implicit dependency as contributing unique variance in predicting past major depression.

Divalent Cations Regulate the Ion Conductance Properties of Diverse Classes of Aquaporins

Directory of Open Access Journals (Sweden)

Mohamad Kourghi

2017-11-01

Full Text Available Aquaporins (AQPs are known to facilitate water and solute fluxes across barrier membranes. An increasing number of AQPs are being found to serve as ion channels. Ion and water permeability of selected plant and animal AQPs (plant Arabidopsis thaliana AtPIP2;1, AtPIP2;2, AtPIP2;7, human Homo sapiens HsAQP1, rat Rattus norvegicus RnAQP4, RnAQP5, and fly Drosophila melanogaster DmBIB were expressed in Xenopus oocytes and examined in chelator-buffered salines to evaluate the effects of divalent cations (Ca2+, Mg2+, Ba2+ and Cd2+ on ionic conductances. AtPIP2;1, AtPIP2;2, HsAQP1 and DmBIB expressing oocytes had ionic conductances, and showed differential sensitivity to block by external Ca2+. The order of potency of inhibition by Ca2+ was AtPIP2;2 > AtPIP2;1 > DmBIB > HsAQP1. Blockage of the AQP cation channels by Ba2+ and Cd2+ caused voltage-sensitive outward rectification. The channels with the highest sensitivity to Ca2+ (AtPIP2;1 and AtPIP2;2 showed a distinctive relief of the Ca2+ block by co-application of excess Ba2+, suggesting that divalent ions act at the same site. Recognizing the regulatory role of divalent cations may enable the discovery of other classes of AQP ion channels, and facilitate the development of tools for modulating AQP ion channels. Modulators of AQPs have potential value for diverse applications including improving salinity tolerance in plants, controlling vector-borne diseases, and intervening in serious clinical conditions involving AQPs, such as cancer metastasis, cardiovascular or renal dysfunction.

Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia

Directory of Open Access Journals (Sweden)

Amelia J. Carr, Philo U. Saunders, Brent S. Vallance, Laura A. Garvican-Lewis, Christopher J. Gore

2015-12-01

Full Text Available This study examined effects of low altitude training and a live-high: train-low protocol (combining both natural and simulated modalities on haemoglobin mass (Hbmass, maximum oxygen consumption (VO2max, time to exhaustion, and submaximal exercise measures. Eighteen elite-level race-walkers were assigned to one of two experimental groups; lowHH (low Hypobaric Hypoxia: continuous exposure to 1380 m for 21 consecutive days; n = 10 or a combined low altitude training and nightly Normobaric Hypoxia (lowHH+NHnight: living and training at 1380 m, plus 9 h.night-1 at a simulated altitude of 3000 m using hypoxic tents; n = 8. A control group (CON; n = 10 lived and trained at 600 m. Measurement of Hbmass, time to exhaustion and VO2max was performed before and after the training intervention. Paired samples t-tests were used to assess absolute and percentage change pre and post-test differences within groups, and differences between groups were assessed using a one-way ANOVA with least significant difference post-hoc testing. Statistical significance was tested at p < 0.05. There was a 3.7% increase in Hbmass in lowHH+NHnight compared with CON (p = 0.02. In comparison to baseline, Hbmass increased by 1.2% (±1.4% in the lowHH group, 2.6% (±1.8% in lowHH+NHnight, and there was a decrease of 0.9% (±4.9% in CON. VO2max increased by ~4% within both experimental conditions but was not significantly greater than the 1% increase in CON. There was a ~9% difference in pre and post-intervention values in time to exhaustion after lowHH+NH-night (p = 0.03 and a ~8% pre to post-intervention difference (p = 0.006 after lowHH only. We recommend low altitude (1380 m combined with sleeping in altitude tents (3000 m as one effective alternative to traditional altitude training methods, which can improve Hbmass.

Mentha arvensis (Linn.-mediated green silver nanoparticles trigger caspase 9-dependent cell death in MCF7 and MDA-MB-231 cells

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Banerjee PP

2017-04-01

exhibited significant cytotoxicity toward breast cancer cells (MCF7 and MDA-MB-231, which were at par with that of CSNPs. Cell cycle analyses of MCF7 cells revealed a significant increase in sub-G1 cell population, indicating cytotoxicity of GSNPs. On the other hand, human peripheral blood lymphocytes showed significantly less cytotoxicity compared with MCF7 and MDA-MB-231 cells when treated with the same dose. Expression patterns of proteins suggested that GSNPs triggered caspase 9-dependent cell death in both cell lines. The Ames test showed that GSNPs were nonmutagenic in nature. Conclusion: GSNPs synthesized using Mentha arvensis may be considered as a promising anticancer agent in breast cancer therapy. They are less toxic and nonmutagenic and mediate caspase 9-dependent apoptosis in MCF7 and MDA-MB-231 cells. Keywords: nanoparticles, EDX, TEM, breast cancer cells, anticancer, nonmutagenic 

Spatially-Dependent Modelling of Pulsar Wind Nebula G0.9+0.1

Science.gov (United States)

van Rensburg, C.; Krüger, P. P.; Venter, C.

2018-03-01

We present results from a leptonic emission code that models the spectral energy distribution of a pulsar wind nebula by solving a Fokker-Planck-type transport equation and calculating inverse Compton and synchrotron emissivities. We have created this time-dependent, multi-zone model to investigate changes in the particle spectrum as they traverse the pulsar wind nebula, by considering a time and spatially-dependent B-field, spatially-dependent bulk particle speed implying convection and adiabatic losses, diffusion, as well as radiative losses. Our code predicts the radiation spectrum at different positions in the nebula, yielding the surface brightness versus radius and the nebular size as function of energy. We compare our new model against more basic models using the observed spectrum of pulsar wind nebula G0.9+0.1, incorporating data from H.E.S.S. as well as radio and X-ray experiments. We show that simultaneously fitting the spectral energy distribution and the energy-dependent source size leads to more stringent constraints on several model parameters.

Aquaporin-4 inhibition mediates piroxicam-induced neuroprotection against focal cerebral ischemia/reperfusion injury in rodents.

Science.gov (United States)

Bhattacharya, Pallab; Pandey, Anand Kumar; Paul, Sudip; Patnaik, Ranjana; Yavagal, Dileep R

2013-01-01

Aquaporin-4(AQP4) is an abundant water channel protein in brain that regulates water transport to maintain homeostasis. Cerebral edema resulting from AQP4 over expression is considered to be one of the major determinants for progressive neuronal insult during cerebral ischemia. Although, both upregulation and downregulation of AQP4 expression is associated with brain pathology, over expression of AQP4 is one of the chief contributors of water imbalance in brain during ischemic pathology. We have found that Piroxicam binds to AQP4 with optimal binding energy value. Thus, we hypothesized that Piroxicam is neuroprotective in the rodent cerebral ischemic model by mitigating cerebral edema via AQP4 regulation. Rats were treated with Piroxicam OR placebo at 30 min prior, 2 h post and 4 h post 60 minutes of MCAO followed by 24 hour reperfusion. Rats were evaluated for neurological deficits and motor function just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, biochemical analysis, RT-PCR and western blot experiments. Piroxicam pretreatment thirty minutes prior to ischemia and four hour post reperfusion afforded neuroprotection as evident through significant reduction in cerebral infarct volume, improvement in motor behavior, neurological deficit and reduction in brain edema. Furthermore, ischemia induced surge in levels of nitrite and malondialdehyde were also found to be significantly reduced in ischemic brain regions in treated animals. This neuroprotection was found to be associated with inhibition of acid mediated rise in intracellular calcium levels and also downregulated AQP4 expression. Findings of the present study provide significant evidence that Piroxicam acts as a potent AQP4 regulator and renders neuroprotection in focal cerebral ischemia. Piroxicam could be clinically exploited for the treatment of brain stroke along with other anti-stroke therapeutics in future.

Pretreatment with Shuanghe-Tang Extract Attenuates Postischemic Brain Injury and Edema in a Mouse Model of Stroke: An Analysis of Medicinal Herbs Listed in Dongui Bogam

Directory of Open Access Journals (Sweden)

Min Jae Kim

2018-01-01

Full Text Available Aim. Although stroke is among the leading causes of death and long-term disability, there are few effective treatments for limiting the severity of neurological sequelae. We evaluated the effects of 29 medicinal herbs listed in the Pung chapter of the 17th century Korean medical text Dongui Bogam on stroke symptoms in a mouse model of cerebral ischemia. Methods. Focal cerebral ischemia was induced via photothrombosis. Infarct volume, brain edema, and neurological deficits were evaluated. Immunofluorescence staining for tight junction proteins and aquaporin 4 (AQP4 was performed following ischemic injury. Results. Based on our initial findings, we examined the effects of two prescriptions in which the candidate herbs comprised more than 60% of the total formula: Shuanghe-tang and Zengsunsiwu-tang. Pretreatment with Shuanghe-tang significantly reduced infarct volume, decreased blood-brain barrier (BBB breakdown, attenuated edema, and improved neurological and motor functions in a dose-dependent manner (30, 100, and 300 mg/kg, while no such effects were observed in mice pretreated with Zengsunsiwu-tang. Immunohistochemical analysis revealed significant increases in ipsilateral occludin and zonula occludens 1 (ZO-1 expression in Shuanghe-tang-pretreated mice, as well as increased AQP4 immunofluorescence. Conclusions. These results indicate that Shuanghe-tang may protect against brain injury and promote recovery of neurological function following ischemia.

Detection on emamectin benzoate-induced apoptosis and DNA damage in Spodoptera frugiperda Sf-9 cell line.

Science.gov (United States)

Wu, Xiwei; Zhang, Lei; Yang, Chao; Zong, Mimi; Huang, Qingchun; Tao, Liming

2016-01-01

Emamectin benzoate (EMB), an important macrocyclic lactone insecticide that belongs to the avermectin family and possesses excellent potency in controlling pests, is non-carcinogenic and non-mutagenic conducted in rats and mice, but EMB-induced cytotoxicity and genotoxicity in arthropod insect have been seldom reported yet. In the present paper, we quantified the cytotoxicity of EMB through the detections on cell viability, DNA damage, and cell apoptosis in Spodoptera frugiperda Sf-9 cells in vitro. The results showed that EMB caused a concentration- and time-dependent reduction on the viability of Sf-9 cells, and the median inhibitory concentrations (IC50) were 3.34μM at 72h of exposure. The dual acridine orange/ethidium bromide staining showed that exposure to EMB induced a significant time- and concentration-dependent increase on cell apoptosis. The alkaline comet assay revealed that EMB induced significant increases on single-strand DNA breaks, and the percentage of γH2AX-positive cells represented a time- and concentration-dependent formation of DNA double-strand breaks in Sf-9 cells. Interestingly, the similar cytotoxic actions of EMB also went for the human cancerous HeLa cells as a control cell group. Data demonstrated the potential cytotoxic effect of EMB on Sf-9 cells that was significantly greater than the effect of hydrogen peroxide at the same concentrations. Copyright © 2015 Elsevier Inc. All rights reserved.

Energy-Dependent microscopic optical potential for p+{sup 9}Be elastic scattering

Energy Technology Data Exchange (ETDEWEB)

Maridi, H. M., E-mail: h.maridi@gmail.com [Physics Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen); Farag, M. Y. H., E-mail: yehiafarag@cu.edu.eg; Esmael, E. H. [Physics Department, Faculty of Applied Science, Taiz University, Taiz (Yemen)

2016-06-10

The p+{sup 9}Be elastic scattering at an energy range up to 200 MeV/nucleon is analyzed using the single-folding model. The density- and isospin-dependent M3Y-Paris nucleon-nucleon (NN) interaction is used for the real part and the NN-scattering amplitude of the high-energy approximation for the imaginary one. The analysis reveals that the cross-section data are reproduced well at energies up to 100 MeV/nucleon by use of the partial-wave expansion. For higher energies, the eikonal approximation give results better than the partial-wave expansion calculations. The volume integrals of the optical-potential parts have systematic energy dependencies, and they are parameterized in empirical formulas.

The acoustical significance of age-dependent ear elongation

DEFF Research Database (Denmark)

Christensen, Flemming

2015-01-01

, corresponding to what is reported in the literature. For female ears, virtually no acoustical effect was found. For male ears directional dependent effects in the range up to 5 dB on average was found for certain directions and frequencies. Implications on age dependent hearing loss (presbycusis...

Omega-3 fatty acid therapy dose-dependently and significantly decreased triglycerides and improved flow-mediated dilation, however, did not significantly improve insulin sensitivity in patients with hypertriglyceridemia.

Science.gov (United States)

Oh, Pyung Chun; Koh, Kwang Kon; Sakuma, Ichiro; Lim, Soo; Lee, Yonghee; Lee, Seungik; Lee, Kyounghoon; Han, Seung Hwan; Shin, Eak Kyun

2014-10-20

Experimental studies demonstrate that higher intake of omega-3 fatty acids (n-3 FA) improves insulin sensitivity, however, we reported that n-3 FA 2g therapy, most commonly used dosage did not significantly improve insulin sensitivity despite reducing triglycerides by 21% in patients. Therefore, we investigated the effects of different dosages of n-3 FA in patients with hypertriglyceridemia. This was a randomized, single-blind, placebo-controlled, parallel study. Age, sex, and body mass index were matched among groups. All patients were recommended to maintain a low fat diet. Forty-four patients (about 18 had metabolic syndrome/type 2 diabetes mellitus) in each group were given placebo, n-3 FA 1 (O1), 2 (O2), or 4 g (O4), respectively daily for 2 months. n-3 FA therapy dose-dependently and significantly decreased triglycerides and triglycerides/HDL cholesterol and improved flow-mediated dilation, compared with placebo (by ANOVA). However, each n-3 FA therapy did not significantly decrease high-sensitivity C-reactive protein and fibrinogen, compared with placebo. O1 significantly increased insulin levels and decreased insulin sensitivity (determined by QUICKI) and O2 significantly decreased plasma adiponectin levels relative to baseline measurements. Of note, when compared with placebo, each n-3 FA therapy did not significantly change insulin, glucose, adiponectin, glycated hemoglobin levels and insulin sensitivity (by ANOVA). We observed similar results in a subgroup of patients with the metabolic syndrome. n-3 FA therapy dose-dependently and significantly decreased triglycerides and improved flow-mediated dilation. Nonetheless, n-3 FA therapy did not significantly improve acute-phase reactants and insulin sensitivity in patients with hypertriglyceridemia, regardless of dosages. Copyright © 2014. Published by Elsevier Ireland Ltd.

Liver-specific Aquaporin 11 knockout mice show rapid vacuolization of the rough endoplasmic reticulum in periportal hepatocytes after amino acid feeding

DEFF Research Database (Denmark)

Rojek, Aleksandra; Füchtbauer, Ernst-Martin; Füchtbauer, Annette C.

2013-01-01

-specific Aqp11 KO mice, allowing us to study the role of AQP11 protein in liver of mice with normal kidney function. The unchallenged liver-specific Aqp11 KO mice have normal longevity, their livers appeared normal, and the plasma biochemistries revealed only a minor defect in lipid handling. Fasting......Aquaporin 11 (AQP11) is a protein channel expressed intracellularly in multiple organs, yet its physiological function is unclear. Aqp11 knockout (KO) mice die early due to malfunction of the kidney, a result of hydropic degeneration of proximal tubule cells. Here we report the generation of liver...... protein or larger doses of various amino acids. The fasting/refeeding challenge is associated with increased expression of markers of ER stress Grp78 and GADD153 and decreased glutathione levels, suggesting that ER stress may play role in the development of vacuoles in the AQP11-deficient hepatocytes. NMR...

Water Transport Mediated by Other Membrane Proteins.

Science.gov (United States)

Huang, Boyue; Wang, Hongkai; Yang, Baoxue

2017-01-01

Water transport through membrane is so intricate that there are still some debates. (Aquaporins) AQPs are entirely accepted to allow water transmembrane movement depending on osmotic gradient. Cotransporters and uniporters , however, are also concerned in water homeotatsis. Urea transporter B (UT-B) has a single-channel water permeability that is similar to AQP1. Cystic fibrosis transmembrane conductance regulator (CFTR ) was initially thought as a water channel but now not believed to transport water directly. By cotranporters, water is transported by water osmosis coupling with substrates, which explains how water is transported across the isolated small intestine. This chapter provides information about water transport mediated by other membrane proteins except AQPs .

Plaque deposition dependent decrease in 5-HT2A serotonin receptor in AbetaPPswe/PS1dE9 amyloid overexpressing mice

DEFF Research Database (Denmark)

Holm, Peter; Ettrup, Anders; Klein, Anders B

2010-01-01

-HT2A receptor regulation in double transgenic AbetaPPswe/PS1dE9 mice which display excess production of Abeta and age-dependent increase in amyloid plaques. Three different age-groups, 4-month-old, 8- month-old, and 11-month-old were included in the study. [3H]-MDL100907, [3H]-escitalopram, and [11C...

MET-2-Dependent H3K9 Methylation Suppresses Transgenerational Small RNA Inheritance.

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Lev, Itamar; Seroussi, Uri; Gingold, Hila; Bril, Roberta; Anava, Sarit; Rechavi, Oded

2017-04-24

In C. elegans, alterations to chromatin produce transgenerational effects, such as inherited increase in lifespan and gradual loss of fertility. Inheritance of histone modifications can be induced by double-stranded RNA-derived heritable small RNAs. Here, we show that the mortal germline phenotype, which is typical of met-2 mutants, defective in H3K9 methylation, depends on HRDE-1, an argonaute that carries small RNAs across generations, and is accompanied by accumulated transgenerational misexpression of heritable small RNAs. We discovered that MET-2 inhibits small RNA inheritance, and, as a consequence, induction of RNAi in met-2 mutants leads to permanent RNAi responses that do not terminate even after more than 30 generations. We found that potentiation of heritable RNAi in met-2 animals results from global hyperactivation of the small RNA inheritance machinery. Thus, changes in histone modifications can give rise to drastic transgenerational epigenetic effects, by controlling the overall potency of small RNA inheritance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Complement-independent retinal pathology produced by intravitreal injection of neuromyelitis optica immunoglobulin G

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Christian M. Felix

2016-10-01

Full Text Available Abstract Background Neuromyelitis optica (NMO, an autoimmune inflammatory disease of the central nervous system, is often associated with retinal abnormalities including thinning of the retinal nerve fiber layer and microcystic changes. Here, we demonstrate that passive transfer of an anti-aquaporin-4 autoantibody (AQP4-IgG produces primary retinal pathology. Methods AQP4-IgG was delivered to adult rat retinas by intravitreal injection. Rat retinas and retinal explant cultures were assessed by immunofluorescence. Results Immunofluorescence showed AQP4-IgG deposition on retinal Müller cells, with greatly reduced AQP4 expression and increased glial fibrillary acidic protein by 5 days. There was mild retinal inflammation with microglial activation but little leukocyte infiltration and loss of retinal ganglion cells by 30 days with thinning of the ganglion cell complex. Interestingly, the loss of AQP4 was complement independent as seen in cobra venom factor-treated rats and in normal rats administered a mutated AQP4-IgG lacking complement effector function. Exposure of ex vivo retinal cultures to AQP4-IgG produced a marked reduction in AQP4 expression by 24 h, which was largely prevented by inhibitors of endocytosis or lysosomal acidification. Conclusions Passive transfer of AQP4-IgG results in primary, complement-independent retinal pathology, which might contribute to retinal abnormalities seen in NMO patients.

The human CFTR protein expressed in CHO cells activates aquaporin-3 in a cAMP-dependent pathway: study by digital holographic microscopy

KAUST Repository

Jourdain, P.

2013-12-11

The transmembrane water movements during cellular processes and their relationship to ionic channel activity remain largely unknown. As an example, in epithelial cells it was proposed that the movement of water could be directly linked to cystic fibrosis transmembrane conductance regulator (CFTR) protein activity through a cAMP-stimulated aqueous pore, or be dependent on aquaporin. Here, we used digital holographic microscopy (DHM) an interferometric technique to quantify in situ the transmembrane water fluxes during the activity of the epithelial chloride channel, CFTR, measured by patch-clamp and iodide efflux techniques. We showed that the water transport measured by DHM is fully inhibited by the selective CFTR blocker CFTRinh172 and is absent in cells lacking CFTR. Of note, in cells expressing the mutated version of CFTR (F508del-CFTR), which mimics the most common genetic alteration encountered in cystic fibrosis, we also show that the water movement is profoundly altered but restored by pharmacological manipulation of F508del-CFTR-defective trafficking. Importantly, whereas activation of this endogenous water channel required a cAMP-dependent stimulation of CFTR, activation of CFTR or F508del-CFTR by two cAMP-independent CFTR activators, genistein and MPB91, failed to trigger water movements. Finally, using a specific small-interfering RNA against the endogenous aquaporin AQP3, the water transport accompanying CFTR activity decreased. We conclude that water fluxes accompanying CFTR activity are linked to AQP3 but not to a cAMP-stimulated aqueous pore in the CFTR protein.

Serological markers associated with neuromyelitis optica spectrum disorders in South India

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Lekha Pandit

2016-01-01

Full Text Available Background: Neuromyelitis optica spectrum disorders (NMOSDs represent 20% of all demyelinating disorders in South India. No studies have determined the seroprevalence to both antibodies against aquaporin-4FNx01 and antimyelin oligodendrocyte glycoprotein antibody (anti-MOG+ in this population. Objective: To identify and characterize seropositive patients for anti-aquaporin-4 antibody (anti-AQP4+ and anti-MOG+ in South India. Materials and Methods: We included 125 consecutive patients (15 children who were serologically characterized using live transfected cells to human M23-AQP4 or full-length MOG. Results: Among a total of 125 patients, 30.4% of patients were anti-AQP4+, 20% were anti-MOG+, and 49.6% were seronegative. No patient was positive for both. Anti-MOG+ patients represented 28.7% (25/87 of seronegative NMOSD. In comparison to anti-AQP4+ patients, anti-MOG+ patients were commonly male, had less frequent attacks and milder disability on expanded disability status score scale. Seronegative patients were also predominantly male, 36% (9/25 had monophasic longitudinally extensive transverse myelitis and disability was comparable with anti-AQP4+ patients. Lumbar cord involvement was common in anti-MOG+ and seronegatives, whereas anti-AQP4+ patients had more cervical lesions. Conclusion: Anti-AQP4+/anti-MOG + patients accounted for nearly half of the patients suspected of having NMOSD in South India, indicating that antibody testing may be useful on the management of subgroups with different prognosis.

DNase Sda1 allows invasive M1T1 Group A Streptococcus to prevent TLR9-dependent recognition.

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Satoshi Uchiyama

Full Text Available Group A Streptococcus (GAS has developed a broad arsenal of virulence factors that serve to circumvent host defense mechanisms. The virulence factor DNase Sda1 of the hyperinvasive M1T1 GAS clone degrades DNA-based neutrophil extracellular traps allowing GAS to escape extracellular killing. TLR9 is activated by unmethylated CpG-rich bacterial DNA and enhances innate immune resistance. We hypothesized that Sda1 degradation of bacterial DNA could alter TLR9-mediated recognition of GAS by host innate immune cells. We tested this hypothesis using a dual approach: loss and gain of function of DNase in isogenic GAS strains and presence and absence of TLR9 in the host. Either DNA degradation by Sda1 or host deficiency of TLR9 prevented GAS induced IFN-α and TNF-α secretion from murine macrophages and contributed to bacterial survival. Similarly, in a murine necrotizing fasciitis model, IFN-α and TNF-α levels were significantly decreased in wild type mice infected with GAS expressing Sda1, whereas no such Sda1-dependent effect was seen in a TLR9-deficient background. Thus GAS Sda1 suppressed both the TLR9-mediated innate immune response and macrophage bactericidal activity. Our results demonstrate a novel mechanism of bacterial innate immune evasion based on autodegradation of CpG-rich DNA by a bacterial DNase.

Indoxyl Sulfate as a Mediator Involved in Dysregulation of Pulmonary Aquaporin-5 in Acute Lung Injury Caused by Acute Kidney Injury

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Nozomi Yabuuchi

2016-12-01

Full Text Available High mortality of acute kidney injury (AKI is associated with acute lung injury (ALI, which is a typical complication of AKI. Although it is suggested that dysregulation of lung salt and water channels following AKI plays a pivotal role in ALI, the mechanism of its dysregulation has not been elucidated. Here, we examined the involvement of a typical oxidative stress-inducing uremic toxin, indoxyl sulfate (IS, in the dysregulation of the pulmonary predominant water channel, aquaporin 5 (AQP-5, in bilateral nephrectomy (BNx-induced AKI model rats. BNx evoked AKI with the increases in serum creatinine (SCr, blood urea nitrogen (BUN and serum IS levels and exhibited thickening of interstitial tissue in the lung. Administration of AST-120, clinically-used oral spherical adsorptive carbon beads, resulted in a significant decrease in serum IS level and thickening of interstitial tissue, which was accompanied with the decreases in IS accumulation in various tissues, especially lung. Interestingly, a significant decrease in AQP-5 expression of lung was observed in BNx rats. Moreover, the BNx-induced decrease in pulmonary AQP-5 protein expression was markedly restored by oral administration of AST-120. These results suggest that BNx-induced AKI causes dysregulation of pulmonary AQP-5 expression, in which IS could play a toxico-physiological role as a mediator involved in renopulmonary crosstalk.

Agmatine Attenuates Brain Edema and Apoptotic Cell Death after Traumatic Brain Injury.

Science.gov (United States)

Kim, Jae Young; Lee, Yong Woo; Kim, Jae Hwan; Lee, Won Taek; Park, Kyung Ah; Lee, Jong Eun

2015-07-01

Traumatic brain injury (TBI) is associated with poor neurological outcome, including necrosis and brain edema. In this study, we investigated whether agmatine treatment reduces edema and apoptotic cell death after TBI. TBI was produced by cold injury to the cerebral primary motor cortex of rats. Agmatine was administered 30 min after injury and once daily until the end of the experiment. Animals were sacrificed for analysis at 1, 2, or 7 days after the injury. Various neurological analyses were performed to investigate disruption of the blood-brain barrier (BBB) and neurological dysfunction after TBI. To examine the extent of brain edema after TBI, the expression of aquaporins (AQPs), phosphorylation of mitogen-activated protein kinases (MAPKs), and nuclear translocation of nuclear factor-κB (NF-κB) were investigated. Our findings demonstrated that agmatine treatment significantly reduces brain edema after TBI by suppressing the expression of AQP1, 4, and 9. In addition, agmatine treatment significantly reduced apoptotic cell death by suppressing the phosphorylation of MAPKs and by increasing the nuclear translocation of NF-κB after TBI. These results suggest that agmatine treatment may have therapeutic potential for brain edema and neural cell death in various central nervous system diseases.

Pancreatic Aquaporin-7: A Novel Target for Anti-diabetic Drugs?

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Méndez-Giménez, Leire; Ezquerro, Silvia; da Silva, Inês V; Soveral, Graça; Frühbeck, Gema; Rodríguez, Amaia

2018-01-01

Aquaporins comprise a family of 13 members of water channels (AQP0-12) that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum. AQP1, AQP5, and AQP8 contribute to fluid secretion especially from ductal cells, whereas AQP12 allows the proper maturation and exocytosis of secretory granules in acinar cells of the exocrine pancreas. The endocrine pancreas (10% of the total pancreatic cells) is composed by the islets of Langerhans, which are distributed in α, β, δ, ε, and pancreatic polypeptide (PP) cells that secrete glucagon, insulin, somatostatin, ghrelin and PP, respectively. AQP7, an aquaglyceroporin permeated by water and glycerol, is expressed in pancreatic β-cells and murine studies have confirmed its participation in insulin secretion, triacylglycerol synthesis and proliferation of these endocrine cells. In this regard, transgenic AQP7-knockout mice develop adult-onset obesity, hyperinsulinemia, increased intracellular triacylglycerol content and reduced β-cell mass in Langerhans islets. Moreover, we have recently reported that AQP7 upregulation in β-cells after bariatric surgery, an effective weight loss surgical procedure, contributes, in part, to the improvement of pancreatic steatosis and insulin secretion through the increase of intracytoplasmic glycerol in obese rats. Human studies remain scarce and controversial, with some rare cases of loss-of function mutations of the AQP7 gene being associated with the onset of type 2 diabetes. The present Review is focused on the role

Pancreatic aquaporin-7: a novel target for anti-diabetic drugs?

Science.gov (United States)

Méndez-Giménez, Leire; Ezquerro, Silvia; da Silva, Inês V.; Soveral, Graça; Frühbeck, Gema; Rodríguez, Amaia

2018-04-01

Aquaporins comprise a family of 13 members of water channels (AQP0-12) that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum. AQP1, AQP5 and AQP8 contribute to fluid secretion especially from ductal cells, whereas AQP12 allows the proper maturation and exocytosis of secretory granules in acinar cells of the exocrine pancreas. The endocrine pancreas (10% of the total pancreatic cells) is composed by the islets of Langerhans, which are distributed in ,, ,  and pancreatic polypeptide (PP) cells that secrete glucagon, insulin, somatostatin, ghrelin and PP, respectively. AQP7, an aquaglyceroporin permeated by water and glycerol, is expressed in pancreatic -cells and murine studies have confirmed its participation in insulin secretion, triacylglycerol synthesis and proliferation of these endocrine cells. In this regard, transgenic AQP7-knockout mice develop adult-onset obesity, hyperinsulinemia, increased intracellular triacylglycerol content and reduced -cell mass in Langerhans islets. Moreover, we have recently reported that AQP7 upregulation in β-cells after bariatric surgery, an effective weight loss surgical procedure, contributes, in part, to the improvement of pancreatic steatosis and insulin secretion by increasing intracellular glycerol in obese rats. Human studies remain scarce and controversial, with some rare cases of loss-of function variants of the AQP7 gene being associated with the onset of type 2 diabetes. The present Review is focused on the role of

Pancreatic Aquaporin-7: A Novel Target for Anti-diabetic Drugs?

Directory of Open Access Journals (Sweden)

Leire Méndez-Giménez

2018-04-01

Full Text Available Aquaporins comprise a family of 13 members of water channels (AQP0-12 that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum. AQP1, AQP5, and AQP8 contribute to fluid secretion especially from ductal cells, whereas AQP12 allows the proper maturation and exocytosis of secretory granules in acinar cells of the exocrine pancreas. The endocrine pancreas (10% of the total pancreatic cells is composed by the islets of Langerhans, which are distributed in α, β, δ, ε, and pancreatic polypeptide (PP cells that secrete glucagon, insulin, somatostatin, ghrelin and PP, respectively. AQP7, an aquaglyceroporin permeated by water and glycerol, is expressed in pancreatic β-cells and murine studies have confirmed its participation in insulin secretion, triacylglycerol synthesis and proliferation of these endocrine cells. In this regard, transgenic AQP7-knockout mice develop adult-onset obesity, hyperinsulinemia, increased intracellular triacylglycerol content and reduced β-cell mass in Langerhans islets. Moreover, we have recently reported that AQP7 upregulation in β-cells after bariatric surgery, an effective weight loss surgical procedure, contributes, in part, to the improvement of pancreatic steatosis and insulin secretion through the increase of intracytoplasmic glycerol in obese rats. Human studies remain scarce and controversial, with some rare cases of loss-of function mutations of the AQP7 gene being associated with the onset of type 2 diabetes. The present Review is

Is late-life dependency increasing or not? A comparison of the Cognitive Function and Ageing Studies (CFAS).

Science.gov (United States)

Kingston, Andrew; Wohland, Pia; Wittenberg, Raphael; Robinson, Louise; Brayne, Carol; Matthews, Fiona E; Jagger, Carol

2017-10-07

Little is known about how the proportions of dependency states have changed between generational cohorts of older people. We aimed to estimate years lived in different dependency states at age 65 years in 1991 and 2011, and new projections of future demand for care. In this population-based study, we compared two Cognitive Function and Ageing Studies (CFAS I and CFAS II) of older people (aged ≥65 years) who were permanently registered with a general practice in three defined geographical areas (Cambridgeshire, Newcastle, and Nottingham; UK). These studies were done two decades apart (1991 and 2011). General practices provided lists of individuals to be contacted and were asked to exclude those who had died or might die over the next month. Baseline interviews were done in the community and care homes. Participants were stratified by age, and interviews occurred only after written informed consent was obtained. Information collected included basic sociodemographics, cognitive status, urinary incontinence, and self-reported ability to do activities of daily living. CFAS I was assigned as the 1991 cohort and CFAS II as the 2011 cohort, and both studies provided prevalence estimates of dependency in four states: high dependency (24-h care), medium dependency (daily care), low dependency (less than daily), and independent. Years in each dependency state were calculated by Sullivan's method. To project future demands for social care, the proportions in each dependency state (by age group and sex) were applied to the 2014 UK [corrected] population projections. Between 1991 and 2011, there were significant increases in years lived from age 65 years with low dependency (1·7 years [95% CI 1·0-2·4] for men and 2·4 years [1·8-3·1] for women) and increases with high dependency (0·9 years [0·2-1·7] for men and 1·3 years [0·5-2·1] for women). The majority of men's extra years of life were spent independent (36·3%) or with low dependency (36·3%) whereas for women

Goreisan Inhibits Upregulation of Aquaporin 4 and Formation of Cerebral Edema in the Rat Model of Juvenile Hypoxic-Ischemic Encephalopathy

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Yano, Hajime; Takahashi, Hisaaki; Yoshimoto, Kouhei; Tsuda, Shinji; Fujiyama, Kenta; Izumo-Shimizu, Yusuke; Motoie, Ryota; Ito, Masanori; Tanaka, Junya; Ishii, Eiichi

2017-01-01

Secondary cerebral edema regulation is of prognostic significance in hypoxic-ischemic encephalopathy (HIE), and aquaporin 4 (AQP4) plays an important role in the pathogenesis of cerebral edema. The traditional Japanese herbal medicine Goreisan relieves brain edema in adults; however, its effect and pharmacological mechanism in children are unknown. We investigated the effects of Goreisan on HIE-associated brain edema and AQP4 expression in a juvenile rat model, established by combined occlusion of middle cerebral and common carotid arteries. Magnetic resonance imaging showed that the lesion areas were significantly smaller in the Goreisan- (2 g/kg) treated group than in the nontreated (saline) group at 24 and 48 h postoperatively. AQP4 mRNA levels in the lesion and nonlesion sides were significantly suppressed in the Goreisan group compared with the nontreated group 36 h postoperatively. Western blotting revealed that levels of AQP4 protein were significantly decreased in the Goreisan group compared with the nontreated group in the lesion side 72 h postoperatively, but not at 12 or 36 h. After 14 days, the Goreisan group had a significantly better survival rate. These findings suggest that Goreisan suppresses brain edema in HIE and improves survival in juvenile rats, possibly via regulation of AQP4 expression and function. PMID:29234383

Goreisan Inhibits Upregulation of Aquaporin 4 and Formation of Cerebral Edema in the Rat Model of Juvenile Hypoxic-Ischemic Encephalopathy

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Yoshiaki Yano

2017-01-01

Full Text Available Secondary cerebral edema regulation is of prognostic significance in hypoxic-ischemic encephalopathy (HIE, and aquaporin 4 (AQP4 plays an important role in the pathogenesis of cerebral edema. The traditional Japanese herbal medicine Goreisan relieves brain edema in adults; however, its effect and pharmacological mechanism in children are unknown. We investigated the effects of Goreisan on HIE-associated brain edema and AQP4 expression in a juvenile rat model, established by combined occlusion of middle cerebral and common carotid arteries. Magnetic resonance imaging showed that the lesion areas were significantly smaller in the Goreisan- (2 g/kg treated group than in the nontreated (saline group at 24 and 48 h postoperatively. AQP4 mRNA levels in the lesion and nonlesion sides were significantly suppressed in the Goreisan group compared with the nontreated group 36 h postoperatively. Western blotting revealed that levels of AQP4 protein were significantly decreased in the Goreisan group compared with the nontreated group in the lesion side 72 h postoperatively, but not at 12 or 36 h. After 14 days, the Goreisan group had a significantly better survival rate. These findings suggest that Goreisan suppresses brain edema in HIE and improves survival in juvenile rats, possibly via regulation of AQP4 expression and function.

Clinical significance of RECK and MMP-9 expression in ... - AJOL

African Journals Online (AJOL)

DR. NJ TONUKARI

2012-04-17

Apr 17, 2012 ... RECK [mouse anti-human monoclonal (MMP-9) or rabbit anti- human polyclonal ..... Li R, Deng Y (2010). Expression of RECK, RAGE and MMP-9 in ... Matrix metalloproteinase-2 and -9 involvement in canine tumors. Vet.

Phospholipase A2 activity-dependent and -independent fusogenic activity of Naja nigricollis CMS-9 on zwitterionic and anionic phospholipid vesicles.

Science.gov (United States)

Chiou, Yi-Ling; Chen, Ying-Jung; Lin, Shinne-Ren; Chang, Long-Sen

2011-11-01

CMS-9, a phospholipase A(2) (PLA(2)) from Naja nigricollis venom, induced the death of human breast cancer MCF-7 cells accompanied with the formation of cell clumps without clear boundaries between cells. Annexin V-FITC staining indicated that abundant phosphatidylserine appeared on the outer membrane of MCF-7 cell clumps, implying the possibility that CMS-9 may promote membrane fusion via anionic phospholipids. To validate this proposition, fusogenic activity of CMS-9 on vesicles composed of zwitterionic phospholipid alone or a combination of zwitterionic and anionic phospholipids was examined. Although CMS-9-induced fusion of zwitterionic phospholipid vesicles depended on PLA(2) activity, CMS-9-induced fusion of vesicles containing anionic phospholipids could occur without the involvement of PLA(2) activity. Membrane-damaging activity of CMS-9 was associated with its fusogenicity. Moreover, CMS-9 induced differently membrane leakage and membrane fusion of vesicles with different compositions. Membrane fluidity and binding capability with phospholipid vesicles were not related to the fusogenicity of CMS-9. However, membrane-bound conformation and mode of CMS-9 depended on phospholipid compositions. Collectively, our data suggest that PLA(2) activity-dependent and -independent fusogenicity of CMS-9 are closely related to its membrane-bound modes and targeted membrane compositions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Increase in IL-6, TNF-a, and MMP-9, but not sICAM-1, concentrations depends on exercise duration

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Reihmane, Dace; Jurka, Antra; Tretjakovs, Peteris

2013-01-01

), tumour necrosis factor-α (TNF-α), soluble form of intercellular adhesion molecule-1 (sICAM-1), and matrix metalloproteinase-9 (MMP-9) was studied in 22 half-marathon (HM) and 18 marathon (M) male amateur runners who completed their exercise task in 1.8 ± 0.2 (mean ± standard deviation) and 3.6 ± 0.4 h...

The MMP-9 -1562 C/T polymorphism in the presence of metabolic syndrome increases the risk of clinical events in patients with coronary artery disease.

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Trine B Opstad

Full Text Available Elevated levels of matrix metalloproteinase (MMP-9 have been associated with the metabolic syndrome (MetS and cardiovascular events. The MMP-9 -1562 C/T polymorphism has furthermore been shown as a risk factor for coronary artery disease (CAD. The non-favourable cardiometabolic state in MetS may increase the risk. We aimed to investigate the influence of MMP-9 -1562 C/T polymorphism in subjects with CAD and MetS.Patients (n = 1000 with verified CAD stratified in Mets +/- (n = 244/756, were analyzed for the MMP-9 -1562 C/T polymorphism and related to clinical events after 2 years follow-up. Serum levels of total MMP-9 and tissue inhibitor of matrix metalloproteinases (TIMP-1 were analyzed in all, whereas MMP-9 activity, extracellular matrix metalloproteinase inducer (EMMPRIN, and expression of the two genes were analyzed in a subset of 240 randomly selected patients.Totally, 106 clinical endpoints were recorded. In MetS; the T-allele associated with 5.5 fold increase in event rate (p<0.0001, increased with number of MetS components, a 117% increase in total MMP-9 levels (TT homozygous, p = 0.05, significantly higher total- and endogenous active MMP-9 and TIMP-1 levels (p<0.01 all, and EMMPRIN was inversely correlated with pro- and endogenous active MMP-9 (p<0.05, both. In non-MetS; the T-allele was not associated with new events, nor higher MMP-9 levels. EMMPRIN was significantly correlated with total MMP-9 and TIMP-1 (p<0.01, both and the two genes were inter-correlated (p<0.001.In CAD patients with MetS, the MMP-9 T-allele increased the risk of clinical events, probably mediated through elevated MMP-9 levels and altered MMP-9 regulation.

Toll-Like Receptor 9-Dependent AMPKα Activation Occurs via TAK1 and Contributes to RhoA/ROCK Signaling and Actin Polymerization in Vascular Smooth Muscle Cells.

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McCarthy, Cameron G; Wenceslau, Camilla F; Ogbi, Safia; Szasz, Theodora; Webb, R Clinton

2018-04-01

Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 5'-AMP-activated protein kinase α (AMPK α ). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPK α activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPK α via transforming growth factor β -activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPK α may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA/Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPK α inhibition. In conclusion, AMPK α phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPK α signaling can mediate VSMC function via RhoA/ROCK activation and actin polymerization. Copyright © 2018 by The

Injury and mechanism of recombinant E. coli expressing STa on piglets colon.

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Lv, Yang; Li, Xueni; Zhang, Lin; Shi, Yutao; DU, Linxiao; Ding, Binying; Hou, Yongqing; Gong, Joshua; Wu, Tao

2018-02-09

Enterotoxigenic Escherichia coli (ETEC) is primary pathogenic bacteria of piglet diarrhea, over two thirds of piglets diarrhea caused by ETEC are resulted from STa-producing ETEC strains. This experiment was conducted to construct the recombinant E. coli expressing STa and study the injury and mechanism of recombinant E. coli expressing STa on 7 days old piglets colon. Twenty-four 7 days old piglets were allotted to four treatments: control group, STa group (2 × 10 9 CFU E. coli LMG194-STa), LMG194 group (2 × 10 9 CFU E. coli LMG194) and K88 group (2 × 10 9 CFU E. coli K88). The result showed that E. coli infection significantly increased diarrhea rates; changed DAO activity in plasma and colon; damaged colonic mucosal morphology including crypt depth, number of globet cells, density of lymphocytes and lamina propria cell density; substantially reduced antioxidant capacity by altering activities of GSH-Px, SOD, and TNOS and productions of MDA and H 2 O 2 ; obviously decreased AQP3, AQP4 and KCNJ13 protein expression levels; substantially altered the gene expression levels of inflammatory cytokines. Conclusively, STa group had the biggest effect on these indices in four treatment groups. These results suggested that the recombinant strain expressed STa can induce piglets diarrhea and colonic morphological and funtional damage by altering expression of proteins connect to transportation function and genes associated with intestinal injury and inflammatory cytokines.

Glymphatic fluid transport controls paravascular clearance of AAV vectors from the brain

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Murlidharan, Giridhar; Crowther, Andrew; Reardon, Rebecca A.; Song, Juan

2016-01-01

Adeno-associated viruses (AAV) are currently being evaluated in clinical trials for gene therapy of CNS disorders. However, host factors that influence the spread, clearance, and transduction efficiency of AAV vectors in the brain are not well understood. Recent studies have demonstrated that fluid flow mediated by aquaporin-4 (AQP4) channels located on astroglial end feet is essential for exchange of solutes between interstitial and cerebrospinal fluid. This phenomenon, which is essential for interstitial clearance of solutes from the CNS, has been termed glial-associated lymphatic transport or glymphatic transport. In the current study, we demonstrate that glymphatic transport profoundly affects various aspects of AAV gene transfer in the CNS. Altered localization of AQP4 in aged mouse brains correlated with significantly increased retention of AAV vectors in the parenchyma and reduced systemic leakage following ventricular administration. We observed a similar increase in AAV retention and transgene expression upon i.c.v. administration in AQP4–/– mice. Consistent with this observation, fluorophore-labeled AAV vectors showed markedly reduced flux from the ventricles of AQP4–/– mice compared with WT mice. These results were further corroborated by reduced AAV clearance from the AQP4-null brain, as demonstrated by reduced transgene expression and vector genome accumulation in systemic organs. We postulate that deregulation of glymphatic transport in aged and diseased brains could markedly affect the parenchymal spread, clearance, and gene transfer efficiency of AAV vectors. Assessment of biomarkers that report the kinetics of CSF flux in prospective gene therapy patients might inform variable treatment outcomes and guide future clinical trial design. PMID:27699236

Structural basis of PAM-dependent target DNA recognition by the Cas9 endonuclease.

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Anders, Carolin; Niewoehner, Ole; Duerst, Alessia; Jinek, Martin

2014-09-25

The CRISPR-associated protein Cas9 is an RNA-guided endonuclease that cleaves double-stranded DNA bearing sequences complementary to a 20-nucleotide segment in the guide RNA. Cas9 has emerged as a versatile molecular tool for genome editing and gene expression control. RNA-guided DNA recognition and cleavage strictly require the presence of a protospacer adjacent motif (PAM) in the target DNA. Here we report a crystal structure of Streptococcus pyogenes Cas9 in complex with a single-molecule guide RNA and a target DNA containing a canonical 5'-NGG-3' PAM. The structure reveals that the PAM motif resides in a base-paired DNA duplex. The non-complementary strand GG dinucleotide is read out via major-groove interactions with conserved arginine residues from the carboxy-terminal domain of Cas9. Interactions with the minor groove of the PAM duplex and the phosphodiester group at the +1 position in the target DNA strand contribute to local strand separation immediately upstream of the PAM. These observations suggest a mechanism for PAM-dependent target DNA melting and RNA-DNA hybrid formation. Furthermore, this study establishes a framework for the rational engineering of Cas9 enzymes with novel PAM specificities.

Clinical Significance and Prognostic Value of CA72-4 Compared with CEA and CA19-9 in Patients with Gastric Cancer

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M. Ychou

2000-01-01

Full Text Available Carcinoembryonic antigen (CEA and CA 19-9 are both widely used in the follow up of patients with gastrointestinal cancer. More recently another tumor marker, named CA 72-4 has been identified and characterized using two different monoclonal antibodies B72.3 and CC49. Several reports evaluated CA 72-4 as a serum tumor marker for gastric cancer and compared its clinical utility with that of CEA or CA 19-9; few reports concerned its prognostic value. In the present study, CA 72-4 is evaluated and compared with CEA and CA 19-9 in various populations of patients with gastric cancer and benign disease; for 52 patients with gastric adenocarcinoma and 57 patients without neoplastic disease CEA, CA 19-9 and CA 72-4 were evaluated before treatment. Sensitivity of the tumor markers CA 72-4, CA 19-9 and CEA at the recommended cut-off level in all 52 patients were 58%, 50% the sensitivity increased to 75%. of these markers, for non metastatic patients, multivariate analyses indicated that none of the markers were significant, when adjusted for gender and age (which were indicators of poor prognosis; patients with abnormal values of CA72-4 tended to have shorter survival than patients with normal values (p < 0.07. In the metastatic population, only high values of CA19-9 (p < 0.02 and gender (women (p < 0.03 were indicators of poor prognosis in univariate analysis; multivariate analysis revealed that both CA72-4 (p = 0.034 and CA19-9 p = 0.009, adjusted for gender were independent prognostic factors. However, CA72-4 lost significance (p = 0.41 when adjusted for CA19-9 and gender, indicating that CA19-9 provides more prognostic information than CA72-4.

Immunodetection of aquaporin 5 in sheep salivary glands related to pasture vegetative cycle

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Silvana Arrighi

2011-10-01

Full Text Available Mammalian aquaporins (AQPs are a family of at least 13 integral membrane proteins expressed in various epithelia, where they function as channels to permeate water and small solutes. AQP5 is widely expressed in the exocrine gland where it is likely involved in providing an appropriate amount of fluid to be secreted with granular contents. As regards AQP5 expression in the salivary glands, literature is lacking concerning domestic animal species. This study was chiefly aimed at immunohistochemically investigating the presence and localization of AQP5 in sheep mandibular and parotid glands. In addition, AQP5 immunoreactivity was comparatively evaluated in animals fed with forage containing different amounts of water related to the pasture vegetative cycle, in order to shed light on the possible response of the gland to environmental modifications. Moderate AQP5-immunoreactivity was shown at the level of the lateral surface of mandibular serous demilune cells, not affected by the pasture vegetative cycle or water content. On the contrary, the parotid gland arcinar cells showed AQP5-immunoreactivity at the level of apical and lateral plasma membrane, which was slight to very strong, according to the pasture vegetative development and interannual climatic variations. AQP5 expression is likely due to its involvement in providing appropriate saliva fluidity. Indeed, the lowest AQP5 immunoreactivity was noticed when food water content increased. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 458–464

Autoantibodies against Muscarinic Type 3 Receptor in Sjögren's Syndrome Inhibit Aquaporin 5 Trafficking

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Lee, Byung Ha; Gauna, Adrienne E.; Perez, Geidys; Park, Yun-jong; Pauley, Kaleb M.; Kawai, Toshihisa; Cha, Seunghee

2013-01-01

Sjögren's syndrome (SjS) is a chronic autoimmune disease that mainly targets the salivary and lacrimal glands. It has been controversial whether anti-muscarinic type 3 receptor (α-M3R) autoantibodies in patients with SjS inhibit intracellular trafficking of aquaporin-5 (AQP5), water transport protein, leading to secretory dysfunction. To address this issue, GFP-tagged human AQP5 was overexpressed in human salivary gland cells (HSG-hAQP5) and monitored AQP5 trafficking to the plasma membrane following carbachol (CCh, M3R agonist) stimulation. AQP5 trafficking was indeed mediated by M3R stimulation, shown in partial blockage of trafficking by M3R-antagonist 4-DAMP. HSG-hAQP5 pre-incubated with SjS plasma for 24 hours significantly reduced AQP5 trafficking with CCh, compared with HSG-hAQP5 pre-incubated with healthy control (HC) plasma. This inhibition was confirmed by monoclonal α-M3R antibody and pre-absorbed plasma. Interestingly, HSG-hAQP5 pre-incubated with SjS plasma showed no change in cell volume, compared to the cells incubated with HC plasma showing shrinkage by twenty percent after CCh-stimulation. Our findings clearly indicate that binding of anti-M3R autoantibodies to the receptor, which was verified by immunoprecipitation, suppresses AQP5 trafficking to the membrane and contribute to impaired fluid secretion in SjS. Our current study urges further investigations of clinical associations between SjS symptoms, such as degree of secretory dysfunction, cognitive impairment, and/or bladder irritation, and different profiles (titers, isotypes, and/or specificity) of anti-M3R autoantibodies in individuals with SjS. PMID:23382834

Time-dependent reversal of significant intrapulmonary shunt after liver transplantation.

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Jin, Xin; Sun, Byung Joo; Song, Jae-Kwan; Roh, Jae-Hyung; Jang, Jeong Yoon; Kim, Dae-Hee; Lim, Young-Suk; Song, Jong-Min; Kang, Duk-Hyun; Lee, Sung Gyu

2018-03-05

Although the association between intrapulmonary shunt (IPS) and liver cirrhosis is clear, data of repeated contrast echocardiography (CE) before and after liver transplantation (LT) to evaluate factors associated with IPS are limited. Hand-agitated saline was used for CE and, by assessing left-chamber opacification, IPS was classified as grade 0 to 4. Grade 3/4 constituted significant IPS and hepatopulmonary syndrome (HPS) was defined as significant IPS with the arterial partial pressure of oxygen < 70 mmHg. Before LT, 253 patients underwent CE and the frequency of significant IPS and HPS were 44% (n = 112) and 7% (n = 17), respectively. Child-Pugh score (odds ratio [OR], 1.345; 95% confidence interval [CI], 1.090 to 1.660; p = 0.006) and arterial oxygen content (OR, 0.838; 95% CI, 0.708 to 0.991; p = 0.039) were independent determinants of significant IPS, whereas direct bilirubin (OR, 1.076; 95% CI, 1.012 to 1.144; p = 0.019) was the only variable associated with HPS. Among 153 patients who underwent successful LT, repeated CE was performed in 97 (63%), which showed significant reductions in IPS grade (from 2.6 ± 1.0 to 1.2 ± 1.3, p < 0.001) and the prevalence of significant IPS (from 56% to 20%, p = 0.038). After adjustment for pre-LT IPS grade, time from LT to repeated CE presented negative linear relationship with post-LT IPS grade (r 2 = 0.366, p < 0.001) and was the only determinant of post-LT IPS grade (OR, 1.009; 95% CI, 1.003 to 1.014; p = 0.004). Repeated CE is useful to evaluate intrapulmonary vascular change before and after LT. Reversal of IPS after successful LT is time-dependent and follow-up duration should be considered for accurate assessment of IPS after LT.

Regulating NETosis: Increasing pH Promotes NADPH Oxidase-Dependent NETosis

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Khan, Meraj A.; Philip, Lijy M.; Cheung, Guillaume; Vadakepeedika, Shawn; Grasemann, Hartmut; Sweezey, Neil; Palaniyar, Nades

2018-01-01

Neutrophils migrating from the blood (pH 7.35–7.45) into the surrounding tissues encounter changes in extracellular pH (pHe) conditions. Upon activation of NADPH oxidase 2 (Nox), neutrophils generate large amounts of H+ ions reducing the intracellular pH (pHi). Nevertheless, how extracellular pH regulates neutrophil extracellular trap (NET) formation (NETosis) is not clearly established. We hypothesized that increasing pH increases Nox-mediated production of reactive oxygen species (ROS) and neutrophil protease activity, stimulating NETosis. Here, we found that raising pHe (ranging from 6.6 to 7.8; every 0.2 units) increased pHi of both activated and resting neutrophils within 10–20 min (Seminaphtharhodafluor dual fluorescence measurements). Since Nox activity generates H+ ions, pHi is lower in neutrophils that are activated compared to resting. We also found that higher pH stimulated Nox-dependent ROS production (R123 generation; flow cytometry, plate reader assay, and imaging) during spontaneous and phorbol myristate acetate-induced NETosis (Sytox Green assays, immunoconfocal microscopy, and quantifying NETs). In neutrophils that are activated and not resting, higher pH stimulated histone H4 cleavage (Western blots) and NETosis. Raising pH increased Escherichia coli lipopolysaccharide-, Pseudomonas aeruginosa (Gram-negative)-, and Staphylococcus aureus (Gram-positive)-induced NETosis. Thus, higher pHe promoted Nox-dependent ROS production, protease activity, and NETosis; lower pH has the opposite effect. These studies provided mechanistic steps of pHe-mediated regulation of Nox-dependent NETosis. Raising pH either by sodium bicarbonate or Tris base (clinically known as Tris hydroxymethyl aminomethane, tromethamine, or THAM) increases NETosis. Each Tris molecule can bind 3H+ ions, whereas each bicarbonate HCO3− ion binds 1H+ ion. Therefore, the amount of Tris solution required to cause the same increase in pH level is less than that of equimolar

Regulating NETosis: Increasing pH Promotes NADPH Oxidase-Dependent NETosis

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Meraj A. Khan

2018-02-01

Full Text Available Neutrophils migrating from the blood (pH 7.35–7.45 into the surrounding tissues encounter changes in extracellular pH (pHe conditions. Upon activation of NADPH oxidase 2 (Nox, neutrophils generate large amounts of H+ ions reducing the intracellular pH (pHi. Nevertheless, how extracellular pH regulates neutrophil extracellular trap (NET formation (NETosis is not clearly established. We hypothesized that increasing pH increases Nox-mediated production of reactive oxygen species (ROS and neutrophil protease activity, stimulating NETosis. Here, we found that raising pHe (ranging from 6.6 to 7.8; every 0.2 units increased pHi of both activated and resting neutrophils within 10–20 min (Seminaphtharhodafluor dual fluorescence measurements. Since Nox activity generates H+ ions, pHi is lower in neutrophils that are activated compared to resting. We also found that higher pH stimulated Nox-dependent ROS production (R123 generation; flow cytometry, plate reader assay, and imaging during spontaneous and phorbol myristate acetate-induced NETosis (Sytox Green assays, immunoconfocal microscopy, and quantifying NETs. In neutrophils that are activated and not resting, higher pH stimulated histone H4 cleavage (Western blots and NETosis. Raising pH increased Escherichia coli lipopolysaccharide-, Pseudomonas aeruginosa (Gram-negative-, and Staphylococcus aureus (Gram-positive-induced NETosis. Thus, higher pHe promoted Nox-dependent ROS production, protease activity, and NETosis; lower pH has the opposite effect. These studies provided mechanistic steps of pHe-mediated regulation of Nox-dependent NETosis. Raising pH either by sodium bicarbonate or Tris base (clinically known as Tris hydroxymethyl aminomethane, tromethamine, or THAM increases NETosis. Each Tris molecule can bind 3H+ ions, whereas each bicarbonate HCO3− ion binds 1H+ ion. Therefore, the amount of Tris solution required to cause the same increase in pH level is less than that of equimolar

Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population.

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Chunxia Peng

Full Text Available This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL and segmented macular layers in optic neuritis (ON in aquaporin4-antibody (AQP4-Ab seropositivity(AQP4-Ab-positiveON patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA and the value of the early diagnosis of neuromyelitis optica (NMO.This is a retrospective, cross-sectional and control observational study.In total, 213 ON patients (291 eyes and 50 healthy controls (HC (100 eyes were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT and BCVA tests. pRNFL and segmented macular layer measurements were analysed.The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0-2 months (-27.61μm versus -14.47 μm and ≥6 months (-57.91μm versus -47.19μm when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0-2 months, reached its peak during 2-4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the pRNFL thickness decreased to 95%CI (50.77�

Skipping one or more dialysis sessions significantly increases mortality: measuring the impact of non-adherence

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Eduardo Gottlieb

2014-06-01

Full Text Available Introduction: Non-adherence to the prescribed dialysis sessions frequency ranges from 2% to 50% of patients. The objective of this study was to evaluate the impact of detecting and measuring the non-adherence to the prescribed dialysis frequency and to determine the importance of a multidisciplinary approach with the aim of improving adherence. Methods: longitudinal cohort study including 8,164 prevalent hemodialysis patients in April 2010, with more than 90 days of treatment, in Fresenius Medical Care Argentina units that were monitored for 3 years. The survey evaluated: interruption of at least one dialysis session in a month or reduction at least 10 minutes of a dialysis session in a month, during 6 months prior to the survey. Relative mortality risks were evaluated among groups. Results: 648 patients (7.9% interrupted dialysis sessions: 320 (3.9% interrupted one session per month and 328 (4.01% interrupted more than one session per month. After 3 years monitoring, 349 patients (53.8 % remained active in hemodialysis and 299 were inactive due to different reasons: 206 deceased (31.8 %, 47 transfers or monitoring losses (7.25 %, 36 transplanted (5.55 %, 8 changes to PD modality (1.2% and 2 recovered their kidney function (0.3 %.Interrupting one session per month significantly increased the mortality risk comparing both groups (interrupters and non-interrupters: RR 2.65 (IC 95% 2.24 – 3.14. Interrupting more than one dialysis session also increased significantly mortality risk comparing to the non-interrupters: RR 2.8 (IC 95% 2.39 – 3.28. After 3 years monitoring, 41.6 % of interrupters at the beginning had improved their adherence through a multidisciplinary program of quality improvement. Conclusion: Global mortality was greater among patients who interrupted dialysis sessions. A considerable proportion of interrupter patients at the beginning modified their behavior through the implementation of a multidisciplinary program of quality

Genome Wide Identification, Phylogeny, and Expression of Aquaporin Genes in Common Carp (Cyprinus carpio.

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Chuanju Dong

Full Text Available Aquaporins (Aqps are integral membrane proteins that facilitate the transport of water and small solutes across cell membranes. Among vertebrate species, Aqps are highly conserved in both gene structure and amino acid sequence. These proteins are vital for maintaining water homeostasis in living organisms, especially for aquatic animals such as teleost fish. Studies on teleost Aqps are mainly limited to several model species with diploid genomes. Common carp, which has a tetraploidized genome, is one of the most common aquaculture species being adapted to a wide range of aquatic environments. The complete common carp genome has recently been released, providing us the possibility for gene evolution of aqp gene family after whole genome duplication.In this study, we identified a total of 37 aqp genes from common carp genome. Phylogenetic analysis revealed that most of aqps are highly conserved. Comparative analysis was performed across five typical vertebrate genomes. We found that almost all of the aqp genes in common carp were duplicated in the evolution of the gene family. We postulated that the expansion of the aqp gene family in common carp was the result of an additional whole genome duplication event and that the aqp gene family in other teleosts has been lost in their evolution history with the reason that the functions of genes are redundant and conservation. Expression patterns were assessed in various tissues, including brain, heart, spleen, liver, intestine, gill, muscle, and skin, which demonstrated the comprehensive expression profiles of aqp genes in the tetraploidized genome. Significant gene expression divergences have been observed, revealing substantial expression divergences or functional divergences in those duplicated aqp genes post the latest WGD event.To some extent, the gene families are also considered as a unique source for evolutionary studies. Moreover, the whole set of common carp aqp gene family provides an

Reducing pulmonary injury by hyperbaric oxygen preconditioning during simulated high altitude exposure in rats.

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Li, Zhuo; Gao, Chunjin; Wang, Yanxue; Liu, Fujia; Ma, Linlin; Deng, Changlei; Niu, Ko-Chi; Lin, Mao-Tsun; Wang, Chen

2011-09-01

Hyperbaric oxygen preconditioning (HBO₂P + HAE) has been found to be beneficial in preventing the occurrence of ischemic damage to brain, spinal cord, heart, and liver in several disease models. In addition, pulmonary inflammation and edema are associated with a marked reduction in the expression levels of both aquaporin (AQP) 1 and AQP5 in the lung. Here, the aims of this study are first to ascertain whether acute lung injury can be induced by simulated high altitude in rats and second to assess whether HBO2P + HAE is able to prevent the occurrence of the proposed high altitude-induced ALI. Rats were randomly divided into the following three groups: the normobaric air (NBA; 21% O₂ at 1 ATA) group, the HBO₂P + high altitude exposure (HAE) group, and the NBA + HAE group. In HBO₂P + HAE group, animals received 100% O₂ at 2.0 ATA for 1 hour per day, for five consecutive days. In HAE groups, animals were exposed to a simulated HAE of 6,000 m in a hypobaric chamber for 24 hours. Right after being taken out to the ambient, animals were anesthetized generally and killed and thoroughly exsanguinated before their lungs were excised en bloc. The lungs were used for both histologic and molecular evaluation and analysis. In NBA + HAE group, the animals displayed higher scores of alveolar edema, neutrophil infiltration, and hemorrhage compared with those of NBA controls. In contrast, the levels of both AQP1 and AQP5 proteins and mRNA expression in the lung in the NBA + HAE group were significantly lower than those of NBA controls. However, the increased lung injury scores and the decreased levels of both AQP1 and AQP5 proteins and mRNA expression in the lung caused by HAE was significantly reduced by HBO₂P + HAE. Our results suggest that high altitude pulmonary injury may be prevented by HBO2P + HAE in rats.

Bright upconversion luminescence and increased Tc in CaBi2Ta2O9:Er high temperature piezoelectric ceramics

International Nuclear Information System (INIS)

Peng Dengfeng; Wang Xusheng; Yao Xi; Xu Chaonan; Lin Jian; Sun Tiantuo

2012-01-01

Er 3+ doped CaBi 2 Ta 2 O 9 (CBT) bismuth layered-structure high temperature piezoelectric ceramics were synthesized by the traditional solid state method. The upconversion (UC) emission properties of Er 3+ doped CBT ceramics were investigated as a function of Er 3+ concentration and incident pump power. A bright green upconverted emission was obtained under excitation 980 nm at room temperature. The observed strong green and weak red emission bands corresponded to the transitions from 4 S 3/2 and 4 F 9/2 to 4 I 15/2 , respectively. The dependence of UC emission intensity on pumping power indicated that a three-photon process was involved in UC emissions. Studies of dielectric with temperature have also been carried out. Introduction of Er increased the Curie temperature of CBT, thus, making this ceramic suitable for sensor applications at higher temperatures. Because of its strong up-converted emission and increased Tc, the multifunctional high temperature piezoelectric ceramic may be useful in high temperature sensor, fluorescence thermometry, and optical-electro integration applications.

Molecular Stress-inducing Compounds Increase Osteoclast Formation in a Heat Shock Factor 1 Protein-dependent Manner*

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Chai, Ryan C.; Kouspou, Michelle M.; Lang, Benjamin J.; Nguyen, Chau H.; van der Kraan, A. Gabrielle J.; Vieusseux, Jessica L.; Lim, Reece C.; Gillespie, Matthew T.; Benjamin, Ivor J.; Quinn, Julian M. W.; Price, John T.

2014-01-01

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss. PMID:24692538

Molecular stress-inducing compounds increase osteoclast formation in a heat shock factor 1 protein-dependent manner.

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Chai, Ryan C; Kouspou, Michelle M; Lang, Benjamin J; Nguyen, Chau H; van der Kraan, A Gabrielle J; Vieusseux, Jessica L; Lim, Reece C; Gillespie, Matthew T; Benjamin, Ivor J; Quinn, Julian M W; Price, John T

2014-05-09

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss.

Temperature dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1}

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Garcia-Escorial, A., E-mail: age@cenim.csic.es [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Lieblich, M. [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Hernando, A.; Aragon, A.; Marin, P. [Instituto de Magnetismo Aplicado, IMA, P.O. Box 155, 28230 Madrid (Spain)

2012-09-25

Highlights: Black-Right-Pointing-Pointer An anomalous thermal dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} powder particles under 25 {mu}m powder particle, increasing Hc as temperature increases. Black-Right-Pointing-Pointer It is proposed that Cu rich regions at inter-grain boundaries could act as exchange decoupling regions contributing to the thermal increase of coercivity. Black-Right-Pointing-Pointer This anomalous thermal dependence points out that tailoring microstructure and size, by controlling the cooling rate of more adequate multiphase systems, could be a promising procedure to develop soft or hard magnets, avoiding Rare Earths metals that is nowadays an important target for the engineering of magnetic materials. - Abstract: In this work, the dependence of the coercive field of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} gas atomized powder with the temperature for different particle sizes has been studied, observing an anomalous behavior in the under 25 powder particle size fraction. This unusual behavior is related with the microstructure of the powder, and is attributed to the presence of a multiphase magnetic system, with non-magnetic regions decoupling the ferromagnetic domains.

Dual effects of N-acetyl-L-cysteine dependent on NQO1 activity: Suppressive or promotive of 9,10-phenanthrenequinone-induced toxicity

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Toyooka, Tatsushi; Shinmen, Takuya; Aarts, Jac M.M.J.G.; Ibuki, Yuko

2012-01-01

A typical antioxidant, N-acetyl-L-cysteine (NAC) generally protects cells from oxidative damage induced by reactive oxygen species (ROS). 9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, produces ROS in redox cycling following two-electron reduction by NAD(P)H:quinone oxidoreductase 1 (NQO1), which has been considered as a cause of its cyto- and genotoxicity. In this study, we show that NAC unexpectedly augments the toxicity of 9,10-PQ in cells with low NQO1 activity. In four human skin cell lines, the expression and the activity of NQO1 were lower than in human adenocarcinoma cell lines, A549 and MCF7. In the skin cells, the cytotoxicity of 9,10-PQ was significantly enhanced by addition of NAC. The formation of DNA double strand breaks accompanying phosphorylation of histone H2AX, was also remarkably augmented. On the other hand, the cyto- and genotoxicity were suppressed by addition of NAC in the adenocarcinoma cells. Two contrasting experiments: overexpression of NQO1 in CHO-K1 cells which originally expressed low NQO1 levels, and knock‐down of NQO1 in the adenocarcinoma cell line A549 by transfection of RNAi, also showed that NAC suppressed 9,10-PQ-induced toxicity in cell lines expressing high NQO1 activity and enhanced it in cell lines with low NQO1 activity. The results suggested that dual effects of NAC on the cyto- and genotoxicity of 9,10-PQ were dependent on tissue-specific NQO1 activity. -- Highlights: ► NAC augmented the cytotoxicity of 9,10-PQ in skin cell lines. ► 9,10-PQ-induced DSBs accompanying γ-H2AX were also augmented by NAC. ► NAC suppressed the cyto- and genotoxicity of 9,10-PQ in adenocarcinoma cell lines. ► The dual effects of NAC on toxicity of 9,10-PQ were dependent on NQO1 activity.

An Insecticide Further Enhances Experience-Dependent Increased Behavioural Responses to Sex Pheromone in a Pest Insect.

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Antoine Abrieux

Full Text Available Neonicotinoid insecticides are widely used to protect plants against pest insects, and insecticide residues remaining in the environment affect both target and non-target organisms. Whereas low doses of neonicotinoids have been shown to disturb the behaviour of pollinating insects, recent studies have revealed that a low dose of the neonicotinoid clothianidin can improve behavioural and neuronal sex pheromone responses in a pest insect, the male moth Agrotis ipsilon, and thus potentially improve reproduction. As male moth behaviour depends also on its physiological state and previous experience with sensory signals, we wondered if insecticide effects would be dependent on plasticity of olfactory-guided behaviour. We investigated, using wind tunnel experiments, whether a brief pre-exposure to the sex pheromone could enhance the behavioural response to this important signal in the moth A. ipsilon at different ages (sexually immature and mature males and after different delays (2 h and 24 h, and if the insecticide clothianidin would interfere with age effects or the potential pre-exposure-effects. Brief pre-exposure to the pheromone induced an age-independent significant increase of sex pheromone responses 24 h later, whereas sex pheromone responses did not increase significantly 2 h after exposure. However, response delays were significantly shorter compared to naïve males already two hours after exposure. Oral treatment with clothianidin increased sex pheromone responses in sexually mature males, confirming previous results, but did not influence responses in young immature males. Males treated with clothianidin after pre-exposure at day 4 responded significantly more to the sex pheromone at day 5 than males treated with clothianidin only and than males pre-exposed only, revealing an additive effect of experience and the insecticide. Plasticity of sensory systems has thus to be taken into account when investigating the effects of sublethal doses

An Insecticide Further Enhances Experience-Dependent Increased Behavioural Responses to Sex Pheromone in a Pest Insect.

Science.gov (United States)

Abrieux, Antoine; Mhamdi, Amel; Rabhi, Kaouther K; Egon, Julie; Debernard, Stéphane; Duportets, Line; Tricoire-Leignel, Hélène; Anton, Sylvia; Gadenne, Christophe

2016-01-01

Neonicotinoid insecticides are widely used to protect plants against pest insects, and insecticide residues remaining in the environment affect both target and non-target organisms. Whereas low doses of neonicotinoids have been shown to disturb the behaviour of pollinating insects, recent studies have revealed that a low dose of the neonicotinoid clothianidin can improve behavioural and neuronal sex pheromone responses in a pest insect, the male moth Agrotis ipsilon, and thus potentially improve reproduction. As male moth behaviour depends also on its physiological state and previous experience with sensory signals, we wondered if insecticide effects would be dependent on plasticity of olfactory-guided behaviour. We investigated, using wind tunnel experiments, whether a brief pre-exposure to the sex pheromone could enhance the behavioural response to this important signal in the moth A. ipsilon at different ages (sexually immature and mature males) and after different delays (2 h and 24 h), and if the insecticide clothianidin would interfere with age effects or the potential pre-exposure-effects. Brief pre-exposure to the pheromone induced an age-independent significant increase of sex pheromone responses 24 h later, whereas sex pheromone responses did not increase significantly 2 h after exposure. However, response delays were significantly shorter compared to naïve males already two hours after exposure. Oral treatment with clothianidin increased sex pheromone responses in sexually mature males, confirming previous results, but did not influence responses in young immature males. Males treated with clothianidin after pre-exposure at day 4 responded significantly more to the sex pheromone at day 5 than males treated with clothianidin only and than males pre-exposed only, revealing an additive effect of experience and the insecticide. Plasticity of sensory systems has thus to be taken into account when investigating the effects of sublethal doses of insecticides

The value of multi ultra high-b-value DWI in grading cerebral astrocytomas and its association with aquaporin-4.

Science.gov (United States)

Tan, Yan; Zhang, Hui; Wang, Xiao-Chun; Qin, Jiang-Bo; Wang, Le

2018-06-01

To investigate the value of multi-ultrahigh-b-value diffusion-weighted imaging (UHBV-DWI) in differentiating high-grade astrocytomas (HGAs) from low-grade astrocytomas (LGAs), analyze its association with aquaporin (AQP) expression. 40 astrocytomas divided into LGAs (N = 15) and HGAs (N = 25) were studied. Apparent diffusion coefficient (ADC) and UHBV-ADC values in solid parts and peritumoral edema were compared between LGAs and HGAs groups by the t-test. Using receiver operating characteristic curves to identify the better parameter. Using real time polymerase chain reaction to assess AQP messenger ribonucleic acid (mRNA). Using spearman correlation analysis to assess the correlation of AQP mRNA with each parameter. ADC values in solid parts of HGAs were significantly lower than LGAs (p = 0.02), while UHBV-ADC values of HGAs were significantly higher than LGAs (p  0.05); ADC value showed a negative correlation with AQP4 mRNA (r = -0.357; p = 0.024). UHBV-ADC value positively correlated with the AQP4 mRNA (r = 0.646; p value may be related with the AQP4 mRNA levels. UHBV-DWI could be of value in the assessment of astrocytoma. Advances in knowledge: UHBV-DWI generated by multi UHBV could have particular value for astrocytoma grading, and the level of AQP4 mRNA might be potentially linked to the change of UHBV-DWI parameter, and we might find the exact reason for the difference of UHBV-ADC between the LGAs and HGAs.

Changes in Transepidermal Water Loss and Skin Hydration according to Expression of Aquaporin-3 in Psoriasis

Science.gov (United States)

Lee, Young; Je, Young-Jin; Lee, Sang-Sin; Li, Zheng Jun; Choi, Dae-Kyoung; Kwon, Yoo-Bin; Sohn, Kyung-Cheol; Im, Myung; Seo, Young Joon

2012-01-01

Background Aquaporins (AQPs) are a family of water transporting proteins present in many mammalian epithelial and endothelial cell types. Among the AQPs, AQP3 is known to be a water/glycerol transporter expressed in human skin. Objective The relationship between the expression level of AQP3 and transpidermal water loss (TEWL) in the lesional and peri-lesional skin of psoriasis-affected patients, and skin hydration in the lesional and peri-lesional skin of psoriasis patients, was investigated. Methods The expression of AQP3 in psoriasis-affected and healthy control skin was determined using immunohistochemical and immunofluroscence staining. TEWL and skin hydration were measured using a Tewameter® TM210 (Courage & Khazaka, Cologne, Germany) and a Corneometer® CM 820 (Courage & Khazaka), respectively. Results AQP3 was mainly expressed in the plasma membrane of stratum corneum and the stratum spinosum in normal epidermis. Unlike the normal epidermis, AQP3 showed decreased expression in the lesional and peri-lesional epidermis of psoriasis. TEWL was increased, and skin hydration was decreased, in the lesional and peri-lesional skin of psoriasis patients, compared with the healthy control sample. Conclusion Although various factors contribute to reduced skin hydration in the lesional and peri-lesional skin of psoriasis, AQP3 appears to be a key factor in the skin dehydration of psoriasis-affected skin. PMID:22577267

INCREASING RELIABILITY OF STEPPED AUTOMATIC STARTING AND RHEOSTAT BREAKING SYSTEM OF ELECTRIC TRAINS ER9T AND EPL9T

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N. H. Visin

2010-06-01

Full Text Available The article examines transitional processes in the power circuit of tractive motors and their influence on the work of stepped automatic starting of electric trains ER9T and EPL9T. The recommendations for increasing the reliability of operation of multiple-unit rolling stock are proposed.

Increased efficiency of targeted mutagenesis by CRISPR/Cas9 in plants using heat stress.

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LeBlanc, Chantal; Zhang, Fei; Mendez, Josefina; Lozano, Yamile; Chatpar, Krishna; Irish, Vivian F; Jacob, Yannick

2018-01-01

The CRISPR/Cas9 system has greatly improved our ability to engineer targeted mutations in eukaryotic genomes. While CRISPR/Cas9 appears to work universally, the efficiency of targeted mutagenesis and the adverse generation of off-target mutations vary greatly between different organisms. In this study, we report that Arabidopsis plants subjected to heat stress at 37°C show much higher frequencies of CRISPR-induced mutations compared to plants grown continuously at the standard temperature (22°C). Using quantitative assays relying on green fluorescent protein (GFP) reporter genes, we found that targeted mutagenesis by CRISPR/Cas9 in Arabidopsis is increased by approximately 5-fold in somatic tissues and up to 100-fold in the germline upon heat treatment. This effect of temperature on the mutation rate is not limited to Arabidopsis, as we observed a similar increase in targeted mutations by CRISPR/Cas9 in Citrus plants exposed to heat stress at 37°C. In vitro assays demonstrate that Cas9 from Streptococcus pyogenes (SpCas9) is more active in creating double-stranded DNA breaks at 37°C than at 22°C, thus indicating a potential contributing mechanism for the in vivo effect of temperature on CRISPR/Cas9. This study reveals the importance of temperature in modulating SpCas9 activity in eukaryotes, and provides a simple method to increase on-target mutagenesis in plants using CRISPR/Cas9. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

The Aquaporin gene family of the yellow fever mosquito, Aedes aegypti.

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Lisa L Drake

2010-12-01

Full Text Available The mosquito, Aedes aegypti, is the principal vector of the Dengue and yellow fever viruses. During feeding, an adult female can take up more than its own body weight in vertebrate blood. After a blood meal females excrete large amounts of urine through their excretion system, the Malpighian tubules (MT. Diuresis starts within seconds after the mosquito starts feeding. Aquaporins (AQPs are a family of membrane transporters that regulate the flow of water, glycerol and other small molecules across cellular membranes in both prokaryotic and eukaryotic cells. Our aim was to identify aquaporins that function as water channels, mediating transcellular water transport in MTs of adult female Ae. aegypti.Using a bioinformatics approach we screened genome databases and identified six putative AQPs in the genome of Ae. aegypti. Phylogenetic analysis showed that five of the six Ae. aegypti AQPs have high similarity to classical water-transporting AQPs of vertebrates. Using microarray, reverse transcription and real time PCR analysis we found that all six AQPs are expressed in distinct patterns in mosquito tissues/body parts. AaAQP1, 4, and 5 are strongly expressed in the adult female MT. RNAi-mediated knockdown of the MT-expressed mosquito AQPs resulted in significantly reduced diuresis.Our results support the notion that AQP1, 4, and 5 function as water transporters in the MTs of adult female Ae. aegypti mosquitoes. Our results demonstrate the importance of these AQPs for mosquito diuresis after blood ingestion and highlight their potential as targets for the development of novel vector control strategies.

The Aquaporin gene family of the yellow fever mosquito, Aedes aegypti.

Science.gov (United States)

Drake, Lisa L; Boudko, Dmitri Y; Marinotti, Osvaldo; Carpenter, Victoria K; Dawe, Angus L; Hansen, Immo A

2010-12-29

The mosquito, Aedes aegypti, is the principal vector of the Dengue and yellow fever viruses. During feeding, an adult female can take up more than its own body weight in vertebrate blood. After a blood meal females excrete large amounts of urine through their excretion system, the Malpighian tubules (MT). Diuresis starts within seconds after the mosquito starts feeding. Aquaporins (AQPs) are a family of membrane transporters that regulate the flow of water, glycerol and other small molecules across cellular membranes in both prokaryotic and eukaryotic cells. Our aim was to identify aquaporins that function as water channels, mediating transcellular water transport in MTs of adult female Ae. aegypti. Using a bioinformatics approach we screened genome databases and identified six putative AQPs in the genome of Ae. aegypti. Phylogenetic analysis showed that five of the six Ae. aegypti AQPs have high similarity to classical water-transporting AQPs of vertebrates. Using microarray, reverse transcription and real time PCR analysis we found that all six AQPs are expressed in distinct patterns in mosquito tissues/body parts. AaAQP1, 4, and 5 are strongly expressed in the adult female MT. RNAi-mediated knockdown of the MT-expressed mosquito AQPs resulted in significantly reduced diuresis. Our results support the notion that AQP1, 4, and 5 function as water transporters in the MTs of adult female Ae. aegypti mosquitoes. Our results demonstrate the importance of these AQPs for mosquito diuresis after blood ingestion and highlight their potential as targets for the development of novel vector control strategies.

Targeted deletion of C1q/TNF-related protein 9 increases food intake, decreases insulin sensitivity, and promotes hepatic steatosis in mice

OpenAIRE

Wei, Zhikui; Lei, Xia; Petersen, Pia S.; Aja, Susan; Wong, G. William

2014-01-01

Transgenic overexpression of CTRP9, a secreted hormone downregulated in obesity, confers striking protection against diet-induced obesity and type 2 diabetes. However, the physiological relevance of this adiponectin-related plasma protein remains undefined. Here, we used gene targeting to establish the metabolic function of CTRP9 in a physiological context. Mice lacking CTRP9 were obese and gained significantly more body weight when fed standard laboratory chow. Increased food intake, due in ...

Expression of a bacterial catalase in a strictly anaerobic methanogen significantly increases tolerance to hydrogen peroxide but not oxygen

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Jennings, Matthew E.; Schaff, Cody W.; Horne, Alexandra J.; Lessner, Faith H.

2014-01-01

Haem-dependent catalase is an antioxidant enzyme that degrades H2O2, producing H2O and O2, and is common in aerobes. Catalase is present in some strictly anaerobic methane-producing archaea (methanogens), but the importance of catalase to the antioxidant system of methanogens is poorly understood. We report here that a survey of the sequenced genomes of methanogens revealed that the majority of species lack genes encoding catalase. Moreover, Methanosarcina acetivorans is a methanogen capable of synthesizing haem and encodes haem-dependent catalase in its genome; yet, Methanosarcina acetivorans cells lack detectable catalase activity. However, inducible expression of the haem-dependent catalase from Escherichia coli (EcKatG) in the chromosome of Methanosarcina acetivorans resulted in a 100-fold increase in the endogenous catalase activity compared with uninduced cells. The increased catalase activity conferred a 10-fold increase in the resistance of EcKatG-induced cells to H2O2 compared with uninduced cells. The EcKatG-induced cells were also able to grow when exposed to levels of H2O2 that inhibited or killed uninduced cells. However, despite the significant increase in catalase activity, growth studies revealed that EcKatG-induced cells did not exhibit increased tolerance to O2 compared with uninduced cells. These results support the lack of catalase in the majority of methanogens, since methanogens are more likely to encounter O2 rather than high concentrations of H2O2 in the natural environment. Catalase appears to be a minor component of the antioxidant system in methanogens, even those that are aerotolerant, including Methanosarcina acetivorans. Importantly, the experimental approach used here demonstrated the feasibility of engineering beneficial traits, such as H2O2 tolerance, in methanogens. PMID:24222618

Aquaporin expression in the Japanese medaka (Oryzias latipes) in freshwater and seawater: challenging the paradigm of intestinal water transport?

DEFF Research Database (Denmark)

Madsen, Steffen; Bujak, Joanna; Tipsmark, Christian

2014-01-01

response to salinity, suggesting that water transport is not regulated at this level. In contrast, mRNA of the Na+,K+,2Cl–-cotransporter type-2 strongly increased in the intestine in SW compared with FW fish. Using custom-made antibodies, Aqp1a, Aqp8ab and Aqp10a were localized in the apical region...... in the intestine of SW fish is surprising, and challenges the paradigm for transepithelial intestinal water absorption in SW fishes....

Increased Mortality in Diabetic Foot Ulcer Patients: The Significance of Ulcer Type

Science.gov (United States)

Chammas, N. K.; Hill, R. L. R.; Edmonds, M. E.

2016-01-01

Diabetic foot ulcer (DFU) patients have a greater than twofold increase in mortality compared with nonulcerated diabetic patients. We investigated (a) cause of death in DFU patients, (b) age at death, and (c) relationship between cause of death and ulcer type. This was an eleven-year retrospective study on DFU patients who attended King's College Hospital Foot Clinic and subsequently died. A control group of nonulcerated diabetic patients was matched for age and type of diabetes mellitus. The cause of death was identified from death certificates (DC) and postmortem (PM) examinations. There were 243 DFU patient deaths during this period. Ischaemic heart disease (IHD) was the major cause of death in 62.5% on PM compared to 45.7% on DC. Mean age at death from IHD on PM was 5 years lower in DFU patients compared to controls (68.2 ± 8.7 years versus 73.1 ± 8.0 years, P = 0.015). IHD as a cause of death at PM was significantly linked to neuropathic foot ulcers (OR 3.064, 95% CI 1.003–9.366, and P = 0.049). Conclusions. IHD is the major cause of premature mortality in DFU patients with the neuropathic foot ulcer patients being at a greater risk. PMID:27213157

Biophysical and Pharmacological Characterization of Nav1.9 Voltage Dependent Sodium Channels Stably Expressed in HEK-293 Cells.

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Zhixin Lin

Full Text Available The voltage dependent sodium channel Nav1.9, is expressed preferentially in peripheral sensory neurons and has been linked to human genetic pain disorders, which makes it target of interest for the development of new pain therapeutics. However, characterization of Nav1.9 pharmacology has been limited due in part to the historical difficulty of functionally expressing recombinant channels. Here we report the successful generation and characterization of human, mouse and rat Nav1.9 stably expressed in human HEK-293 cells. These cells exhibit slowly activating and inactivating inward sodium channel currents that have characteristics of native Nav1.9. Optimal functional expression was achieved by coexpression of Nav1.9 with β1/β2 subunits. While recombinantly expressed Nav1.9 was found to be sensitive to sodium channel inhibitors TC-N 1752 and tetracaine, potency was up to 100-fold less than reported for other Nav channel subtypes despite evidence to support an interaction with the canonical local anesthetic (LA binding region on Domain 4 S6. Nav1.9 Domain 2 S6 pore domain contains a unique lysine residue (K799 which is predicted to be spatially near the local anesthetic interaction site. Mutation of this residue to the consensus asparagine (K799N resulted in an increase in potency for tetracaine, but a decrease for TC-N 1752, suggesting that this residue can influence interaction of inhibitors with the Nav1.9 pore. In summary, we have shown that stable functional expression of Nav1.9 in the widely used HEK-293 cells is possible, which opens up opportunities to better understand channel properties and may potentially aid identification of novel Nav1.9 based pharmacotherapies.

Increased Body Mass Index during Therapy for Childhood Acute Lymphoblastic Leukemia: A Significant and Underestimated Complication

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Helen C. Atkinson

2015-01-01

Full Text Available Objective & Design. We undertook a retrospective review of children diagnosed with acute lymphoblastic leukemia (ALL and treated with modern COG protocols (n=80 to determine longitudinal changes in body mass index (BMI and the prevalence of obesity compared with a healthy reference population. Results. At diagnosis, the majority of patients (77.5% were in the healthy weight category. During treatment, increases in BMI z-scores were greater for females than males; the prevalence of obesity increased from 10.3% to 44.8% (P<0.004 for females but remained relatively unchanged for males (9.8% to 13.7%, P=0.7. Longitudinal analysis using linear mixed-effects identified associations between BMI z-scores and time-dependent interactions with sex (P=0.0005, disease risk (P<0.0001, age (P=0.0001, and BMI z-score (P<0.0001 at diagnosis and total dose of steroid during maintenance (P=0.01. Predicted mean BMI z-scores at the end of therapy were greater for females with standard risk ALL irrespective of age at diagnosis and for males younger than 4 years of age at diagnosis with standard risk ALL. Conclusion. Females treated on standard risk protocols and younger males may be at greatest risk of becoming obese during treatment for ALL. These subgroups may benefit from intervention strategies to manage BMI during treatment for ALL.

Cadmium induces matrix metalloproteinase-9 expression via ROS-dependent EGFR, NF-kB, and AP-1 pathways in human endothelial cells

International Nuclear Information System (INIS)

Lian, Sen; Xia, Yong; Khoi, Pham Ngoc; Ung, Trong Thuan; Yoon, Hyun Joong; Kim, Nam Ho; Kim, Kyung Keun; Jung, Young Do

2015-01-01

Highlights: • Cadmium induces MMP-9 expression through NADPH oxidase-derived ROS. • Cadmium induces MMP-9 through EGFR-mediated Akt, Erk1/2 and JNK1/2 signaling pathways. • Akt, MAPKs (Erk1/2 and JNK1/2) functioned as upstream signals of NF-kB and AP-1 respectively, in cadmium-induced MMP-9 in endothelial cells. • ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression in ECV304 cells. - Abstract: Cadmium (Cd), a widespread cumulative pollutant, is a known human carcinogen, associated with inflammation and tumors. Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in tumor metastasis; however, the mechanisms underlying the MMP-9 expression induced by Cd remain obscure in human endothelial cells. Here, Cd elevated MMP-9 expression in dose- and time-dependent manners in human endothelial cells. Cd increased ROS production and the ROS-producing NADPH oxidase. Cd translocates p47 phox , a key subunit of NADPH oxidase, to the cell membrane. Cd also activated the phosphorylation of EGFR, Akt, Erk1/2, and JNK1/2 in addition to promoting NF-kB and AP-1 binding activities. Specific inhibitor and mutagenesis studies showed that EGFR, Akt, Erk1/2, JNK1/2 and transcription factors NF-κB and AP-1 were related to Cd-induced MMP-9 expression in endothelial cells. Akt, Erk1/2, and JNK1/2 functioned as upstream signals in the activation of NF-κB and AP-1, respectively. In addition, N-acetyl-L-cystein (NAC), diphenyleneiodonium chloride (DPI) and apocynin (APO) inhibited the Cd-induced activation of EGFR, Akt, Erk1/2, JNK1/2, and p38 MAPK, indicating that ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression. At present, it states that Cd displayed marked invasiveness in ECV304 cells, which was partially abrogated by MMP-9 neutralizing antibodies. These results demonstrated that Cd induces MMP-9 expression via ROS-dependent EGFR- > Erk1/2, JNK1/2- > AP-1 and EGFR- > Akt- > NF-κB signaling pathways and, in turn

Increased Coagulation and Decreased Fibrinolysis as Measured with Overall Hemostatic Potential Are Dependent on BMI and Not Associated with PCOS.

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Rakusa, Matej; Jensterle, Mojca; Božič-Mijovski, Mojca; Janez, Andrej

2017-05-01

Overall hemostatic potential (OHP) captures all factors that affect coagulation and fibrinolysis cascade. It has not yet been assessed in polycystic ovary syndrome (PCOS). The aim of the study was to identify the relationship of OHP with a syndrome per se and body mass index (BMI). In 90 women with PCOS aged 30.9 ± 8.1 years (50 obese, 13 overweight, and 27 lean) and 21 healthy age-matched controls (11 obese and 10 lean), OHP with overall coagulation potential (OCP) and overall fibrinolytic potential (OFP) was determined spectrophotometrically. OFP was calculated. OHP increased with BMI in PCOS (9.6 ± 2.3 in lean, 12.5 ± 5.1 in overweight, and 15.5 ± 3.8 Abs-sum in obese) and in controls (9.1 ± 1.0 in lean and 17.3 ± 4.6 Abs-sum in obese). There was significant difference between lean and obese PCOS (P PCOS (P PCOS (P PCOS did not differ significantly, while OHP for healthy obese was increased in comparison to overweight and lean PCOS (P PCOS was not associated with increased OHP compared with BMI and age-matched controls. However, increase in OHP was positively associated with BMI in PCOS and healthy women.

Ménière's Disease: Molecular Analysis of Aquaporins 2, 3 and Potassium Channel KCNE1 Genes in Brazilian Patients.

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Lopes, Karen de Carvalho; Sartorato, Edi Lúcia; da Silva-Costa, Sueli M; de Macedo Adamov, Nadya Soares; Ganança, Fernando Freitas

2016-09-01

Ménière's disease (MD) is a complex disease of unknown etiology characterized by a symptomatic tetrad of vertigo, hearing loss, tinnitus, and aural fullness. In addition to factors related to homeostasis of the inner ear, genetic factors have been implicated in its pathophysiology, including genes related to the transport of water and ionic composition maintenance of the endolymph, such as the aquaporin genes AQP2 and AQP3, and the potassium channel gene KCNE1. The aim of this study was to identify polymorphisms of these genes and determine their association with clinical characteristics of patients with MD. A case-control genetic association study was carried out, including 30 patients with definite Ménière's disease and 30 healthy controls. The coding regions of the target genes were amplified from blood samples by polymerase chain reaction (PCR), followed by direct sequencing. The associations of polymorphisms with clinical characteristics were analyzed with logistic regression. Five polymorphisms were identified: rs426496 in AQP2; rs591810 in AQP3; and rs1805127, rs1805128, and rs17173510 in KCNE1. After adjustment, rs426496 was significantly associated with tinnitus during the initial crisis and with altered electronystagmography, and rs1805127 was significantly associated with nephropathy. The genetic variant rs426496 in AQP2; rs591810 in AQP3 and rs1805127, rs1805128, and rs17173510, in KCNE1 were found in patients with Ménière's disease. The polymorphism rs426496, in AQP2, is associated with tinnitus at the onset of Ménière's disease and altered electronystagmography. In addition, rs1805127, in KCNE1, is associated with the presence of nephropathy.

Increased self-diffusion of brain water in normal aging

DEFF Research Database (Denmark)

Gideon, P; Thomsen, C; Henriksen, O

1994-01-01

With magnetic resonance (MR) imaging, brain water self-diffusion was measured in 17 healthy volunteers 22-76 (mean, 44.6) years old. The calculated values for the apparent diffusion coefficients (ADCs) ranged from 0.58 x 10(-9) to 1.23 x 10(-9) m2/sec in cerebral white matter. A significant...... by an increase in the extracellular volume due to age-dependent neuronal degeneration or to changes in myelination. These findings have implications for future clinical investigations with diffusion MR imaging techniques in patients with neurologic diseases, and stress the importance of having an age...

The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production

DEFF Research Database (Denmark)

Tinning, Anne Robdrup; Jensen, Boye L; Schweda, Frank

2014-01-01

Processing and release of secretory granules involve water movement across granule membranes. It was hypothesized that the water channel aquaporin-1 (AQP-1) contributes directly to recruitment of renin-positive cells in the afferent arteriole. AQP1(-/-) and (+/+) mice were fed a low NaCl diet (LS...... to baseline with no difference between genotypes. Plasma nitrite/nitrate concentration was unaffected by genotype and LS-ACEI. In AQP1(-/-) mice, the number of afferent arterioles with recruitment was significantly lower compared to (+/+) after LS-ACEI. It is concluded that aquaporin-1 is not necessary...... for acutely stimulated renin secretion in vivo and from isolated perfused kidney, whereas recruitment of renin-positive cells in response to chronic stimulation is attenuated or delayed in AQP1(-/-) mice....

Mechanism of increased gluconeogenesis in noninsulin-dependent diabetes mellitus. Role of alterations in systemic, hepatic, and muscle lactate and alanine metabolism.

OpenAIRE

Consoli, A; Nurjhan, N; Reilly, J J; Bier, D M; Gerich, J E

1990-01-01

To assess the mechanisms responsible for increased gluconeogenesis in noninsulin-dependent diabetes mellitus (NIDDM), we infused [3-14C]lactate, [3-13C]alanine, and [6-3H]glucose in 10 postabsorptive NIDDM subjects and in 9 age- and weight-matched nondiabetic volunteers and measured systemic appearance of alanine and lactate, their release from forearm tissues, and their conversion into plasma glucose (corrected for Krebs cycle carbon exchange). Systemic appearance of lactate and alanine were...

Knowledge-fused differential dependency network models for detecting significant rewiring in biological networks.

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Tian, Ye; Zhang, Bai; Hoffman, Eric P; Clarke, Robert; Zhang, Zhen; Shih, Ie-Ming; Xuan, Jianhua; Herrington, David M; Wang, Yue

2014-07-24

Modeling biological networks serves as both a major goal and an effective tool of systems biology in studying mechanisms that orchestrate the activities of gene products in cells. Biological networks are context-specific and dynamic in nature. To systematically characterize the selectively activated regulatory components and mechanisms, modeling tools must be able to effectively distinguish significant rewiring from random background fluctuations. While differential networks cannot be constructed by existing knowledge alone, novel incorporation of prior knowledge into data-driven approaches can improve the robustness and biological relevance of network inference. However, the major unresolved roadblocks include: big solution space but a small sample size; highly complex networks; imperfect prior knowledge; missing significance assessment; and heuristic structural parameter learning. To address these challenges, we formulated the inference of differential dependency networks that incorporate both conditional data and prior knowledge as a convex optimization problem, and developed an efficient learning algorithm to jointly infer the conserved biological network and the significant rewiring across different conditions. We used a novel sampling scheme to estimate the expected error rate due to "random" knowledge. Based on that scheme, we developed a strategy that fully exploits the benefit of this data-knowledge integrated approach. We demonstrated and validated the principle and performance of our method using synthetic datasets. We then applied our method to yeast cell line and breast cancer microarray data and obtained biologically plausible results. The open-source R software package and the experimental data are freely available at http://www.cbil.ece.vt.edu/software.htm. Experiments on both synthetic and real data demonstrate the effectiveness of the knowledge-fused differential dependency network in revealing the statistically significant rewiring in biological

Temperature dependence of the hydrogen-broadening coefficient for the nu 9 fundamental of ethane

Science.gov (United States)

Halsey, G. W.; Hillman, J. J.; Nadler, Shacher; Jennings, D. E.

1988-01-01

Experimental results for the temperature dependence of the H2-broadening coefficient for the nu 9 fundamental of ethane are reported. Measurements were made over the temperature range 95-300 K using a novel low-temperature absorption cell. These spectra were recorded with the Doppler-limited diode laser spectrometer at NASA Goddard. The results are compared with recent measurements and model predictions.

The increase of plasma galectin-9 in a patient with insulin allergy: a case report

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Chagan-Yasutan Haorile

2010-08-01

Full Text Available Abstract Allergic reaction to insulin is known to be associated with eosinophilia and hyper IgE. Recent report showed that eosinophilia is related with the increased synthesis of galectin-9 (GAL-9 and osteopontin (OPN. Here, we examined plasma levels of GAL-9 and OPN first time in a case of 65-year old patient with insulin allergy. Insulin aspart & insulin aspart 30 mix were given to the patient and an elevation of the eosinophil count (8440/μl, 17.6 fold and a moderate increase of IgE (501 U/ml, reference range: 10-350 U/ml, eotaxin-3 (168 pg/ml, 2 fold, histamine (0.95 ng/ml, 5.3 fold were found 33 days later. The plasma levels of GAL-9 and OPN were 22.5 and 1.7 fold higher than the cut-off point, respectively. After one month cessation of insulin therapy, elevations of the eosinophil count (3,480/μl; 7.3 fold, and OPN (1.4 fold still occurred but the GAL-9 levels became normal. Therefore, we noted the increases of GAL-9 and OPN in plasma for the first time in a patient with insulin allergy and propose that GAL-9 reflects the conditions of allergy more accurately.

Hydrogen sulfide increases nitric oxide production from endothelial cells by an Akt-dependent mechanism

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Arturo J Cardounel

2011-12-01

Full Text Available Hydrogen sulfide (H2S and nitric oxide (NO are both gasotransmitters that can elicit synergistic vasodilatory responses in the in the cardiovascular system, but the mechanisms behind this synergy are unclear. In the current study we investigated the molecular mechanisms through which H2S regulates endothelial NO production. Initial studies were performed to establish the temporal and dose-dependent effects of H2S on NO generation using EPR spin trapping techniques. H2S stimulated a two-fold increase in NO production from endothelial nitric oxide synthase (eNOS, which was maximal 30 min after exposure to 25-150 µM H2S. Following 30 min H2S exposure, eNOS phosphorylation at Ser 1177 was significantly increased compared to control, consistent with eNOS activation. Pharmacological inhibition of Akt, the kinase responsible for Ser 1177 phosphorylation, attenuated the stimulatory effect of H2S on NO production. Taken together, these data demonstrate that H2S up-regulates NO production from eNOS through an Akt-dependent mechanism. These results implicate H2S in the regulation of NO in endothelial cells, and suggest that deficiencies in H2S signaling can directly impact processes regulated by NO.

Identification of Loop D Domain Amino Acids in the Human Aquaporin-1 Channel Involved in Activation of the Ionic Conductance and Inhibition by AqB011

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Mohamad Kourghi

2018-04-01

Full Text Available Aquaporins are integral proteins that facilitate the transmembrane transport of water and small solutes. In addition to enabling water flux, mammalian Aquaporin-1 (AQP1 channels activated by cyclic GMP can carry non-selective monovalent cation currents, selectively blocked by arylsulfonamide compounds AqB007 (IC50 170 μM and AqB011 (IC50 14 μM. In silico models suggested that ligand docking might involve the cytoplasmic loop D (between AQP1 transmembrane domains 4 and 5, but the predicted site of interaction remained to be tested. Work here shows that mutagenesis of two conserved arginine residues in loop D slowed the activation of the AQP1 ion conductance and impaired the sensitivity of the channel to block by AqB011. Substitution of residues in loop D with proline showed effects on ion conductance amplitude that varied with position, suggesting that the structural conformation of loop D is important for AQP1 channel gating. Human AQP1 wild type, AQP1 mutant channels with alanines substituted for two arginines (R159A+R160A, and mutants with proline substituted for single residues threonine (T157P, aspartate (D158P, arginine (R159P, R160P, or glycine (G165P were expressed in Xenopus laevis oocytes. Conductance responses were analyzed by two-electrode voltage clamp. Optical osmotic swelling assays and confocal microscopy were used to confirm mutant and wild type AQP1-expressing oocytes were expressed in the plasma membrane. After application of membrane-permeable cGMP, R159A+R160A channels had a significantly slower rate of activation as compared with wild type, consistent with impaired gating. AQP1 R159A+R160A channels showed no significant block by AqB011 at 50 μM, in contrast to the wild type channel which was blocked effectively. T157P, D158P, and R160P mutations had impaired activation compared to wild type; R159P showed no significant effect; and G165P appeared to augment the conductance amplitude. These findings provide evidence for the

Sox9-dependent expression of Gstm6 in Sertoli cells during testis development in mice.

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Beverdam, Annemiek; Svingen, Terje; Bagheri-Fam, Stefan; Bernard, Pascal; McClive, Peter; Robson, Mathew; Khojasteh, Mahdi Banan; Salehi, Mahboubeh; Sinclair, Andrew H; Harley, Vincent R; Koopman, Peter

2009-03-01

Glutathione S-transferases (GSTs) are an important family of multifunctional enzymes that play a role in the protection of tissues by the detoxification of hazardous and carcinogenic compounds. We found previously that Gstm6 is upregulated in the somatic cells of male mouse fetal gonads relative to female gonads. In this study, we describe the spatial and temporal expression pattern of Gstm6 during mouse development. We show that Gstm6 is predominantly expressed in the reproductive system, at significantly higher levels in XY gonads compared with XX gonads from 11.5 dpc onwards, and remains expressed in the testes in adult mice. Its expression is associated with the Sertoli cell lineage, and is dependent on the expression of the male sex-determining gene Sox9. Our data suggest that Gstm6 plays a male-specific role in gonad development or function, possibly by modulating the exposure of somatic tissue and/or germ cells to endogenous or exogenous toxicants.

Effects of cannabinoids Δ(9)-tetrahydrocannabinol, Δ(9)-tetrahydrocannabinolic acid and cannabidiol in MPP+ affected murine mesencephalic cultures.

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