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Jin J.,Wuhan University | Peng C.,Wuhan University | Wu S.-Z.,Wuhan University | Chen H.-M.,Wuhan University | And 2 more authors.
Acta Pharmacologica Sinica | Year: 2015

Aim: RhoA/ROCK signaling plays an important role in diabetic nephropathy, and ROCK inhibitor fasudil exerts nephroprotection in experimental diabetic nephropathy. In this study we investigated the molecular mechanisms underlying the protective actions of fasudil in a rat model of diabetic nephropathy. Methods: Streptozotocin (STZ)-induced diabetic rats, to which fasudil or a positive control drug enalapril were orally administered for 8 months. Metabolic parameters and blood pressure were assessed during the treatments. After the rats were euthanized, kidney samples were collected for histological and molecular biological studies. VEGF, VEGFR1, VEGFR2 and fibronectin expression, and Src and caveolin-1 phosphorylation in the kidneys were assessed using RT-PCR, Western blot and immunohistochemistry assays. The association between VEGFR2 and caveolin-1 was analyzed with immunoprecipitation. Results: Chronic administration of fasudil (30 and 100 mg·kg-1 ·d-1) or enalapril (10 mg/kg, bid) significantly attenuated the glomerular sclerosis and albuminuria in the diabetic rats. Furthermore, fasudil treatment prevented the upregulation of VEGF, VEGFR1, VEGFR2 and fibronectin, and the increased association between VEGFR2 and caveolin-1 in the renal cortices, and partially blocked Src activation and caveolin-1 phosphorylation on tyrosine 14 in the kidneys, whereas enalapril treatment had no effects on the VEGFR2/Src/caveolin-1 signaling pathway.Conclusion:Fasudil exerts protective actions in STZ-induced diabetic nephropathy by blocking the VEGFR2/Src/caveolin-1 signaling pathway and fibronectin upregulation. Thus, VEGFR2 may be a potential therapeutic target for the treatment of diabetic nephropathy.

Wu S.-Z.,Wuhan University | Peng F.-F.,Wuhan University | Li J.-L.,Gannan Medical University | Ye F.,Wuhan University | And 3 more authors.
American Journal of Physiology - Renal Physiology | Year: 2014

Glomerular matrix accumulation is a hallmark of diabetic renal disease. Serine/threonine kinase PKC-β1 mediates glucose-induced Akt S473 phosphorylation, RhoA activation, and transforming growth factor (TGF)-β1 upregulation and finally leads to matrix upregulation in mesangial cells (MCs). It has been reported that glucose-induced PKC-β1 activation is dependent on caveolin-1 and the presence of intact caveolae in MCs; however, whether activated PKC-β1 regulates caveolin-1 expression and phosphorylation are unknown. Here, we showed that, although the caveolin-1 protein level had no significant change, the PKC-β-specific inhibitor LY-333531 blocked caveolin-1 Y14 phosphorylation in high glucose (HG)-treated MCs and in the renal cortex of diabetic rats. The Src-specific inhibitor SU-6656 prevented the HG-induced association between PKC-β1 and caveolin-1 and PKC-β1 membrane translocation, whereas PKC-β1 small interfering RNA failed to block Src activation, indicating that Src kinase is upstream of PKC-β1 activation. Although LY-333531 blocked PKC-β1 membrane translocation, it had no effect on the PKC-β1/caveolin-1 association, suggesting that PKC-β1 activation requires the interaction of caveolin-1 and PKC-β1. PKC-β1-mediated Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation in response to HG were prevented by SU-6656 and nonphosphorylatable mutant caveolin-1 Y14A. In conclusion, Src activation by HG mediates the PKC-β1/caveolin-1 association and PKC-β1 activation, which assists in caveolin-1 Y14 phosphorylation by Src kinase. The downstream effects, including Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation, require caveolin-1 Y14 phosphorylation. Caveolin-1 is thus an important mediator of the profibrogenic process in diabetic renal disease. © 2014 the American Physiological Society.

Jiang T.,Wuhan University | Wen Y.,Wuhan University | Cheng S.,Suizhou Maternal and Child Hospital & Suizhou Childrens Hospital | Xu D.,Wuhan University | And 3 more authors.
Medical Journal of Wuhan University | Year: 2016

Objective: To investigate the role of hypothalamic irritability induced by the prenatal food restriction(PFR) in the stimulated sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis in female offspring rats. Methods: PFR model was established by reducing 50% food administration of the pregnant rats since pregnant day 11. Then, the rats were killed under anaesthesia at pregnant day 20. The left pregnant rats were kept until spontaneous labor. All the female offspring were fed with high fat diet. Then, half of the rats were killed, while the left were underwent unpredictable chronic stresses (UCS) from postnatal week 17 to 20 and killed as well. The blood and hypothalamus were collected. Serum adrenocorticotropic hormone (ACTH), hypothalamic mRNA level of hypothalamus corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP), vesicular glutamate transporter 2 (VGluT2), glutamic acid decarboxylase 65 (GAD65), and ultrastructure of fetal hypothalamus were detected. Results: Abnormal changes in ultrastructure were observed in fetal hypothalamus. The mRNA levels of AVP, GAD65, vGLUT2 were decreased, while the vGLUT2/GAD65 ratio was increased. Before UCS, lower ACTH serum concentration and CRH mRNA level, as well as increased vGLUT2/GAD65 ratio, were detected in PFR group. Then, the rate of the serum ACTH rise, the AVP mRNA level and vGLUT2/GAD65 ratio were elevated after UCS. Conclusion: PFR stimulated the sensitivity of the HPA axis in female offspring rats through boosting the hypothalamic irritability. © 2016, Editorial Board of Medical Journal of Wuhan University. All right reserved.

Chen X.,Wuhan University | Zhang Y.,Wuhan University | Shi Y.,Wuhan University | Lian H.,Wuhan University | And 10 more authors.
Oncotarget | Year: 2016

Abnormalities of autophagy have been implicated in an increasing number of human cancers, including glioma. To date, there is a wealth of evidence indicating that microRNAs (miRNAs) contribute significantly to autophagy in a variety of cancers. Previous studies have suggested that miR-129 functioned as an important inhibitor of the cell cycle and could promote the apoptosis of many cancer cell lines in vitro. Here, we reported that miR-129 acted as a potent inducer of autophagy. Forced expression of miR-129 could induce autophagic flux by targetedly suppressing Notch-1 in glioma cells. The autophagy induced by miR-129 could restrain the activity of mammalian target of rapamycin (mTOR) and upregulate Beclin-1. Moreover, we demonstrated that E2F transcription factor 7 (E2F7) could also trigger autophagic flux by upregulating Beclin-1 and mediating miR-129-induced autophagy. Additionally, knockdown of Notch-1 could upregulate the expression of E2F7, whereas downregulation of E2F7 alleviated shNotch-1-induced autophagic flux. In particular, knockdown of endogenous Beclin-1 could effectively reduce autophagic flux stimulated by miR-129 and E2F7. Interestingly, upon attenuation of miR-129- or E2F7-triggered autophagic flux rescued cell viability suppressed by them. More importantly, intratumoral injection of pHAGEmiR- 129 lentivirus in a nude mouse xenograft model significantly restrained tumor growth and triggered autophagy. In conclusion, these findings identify a new function for miR-129 as a potent inducer of autophagy through a novel Notch-1/E2F7/Beclin-1 axis in glioma.

Xu D.,Wuhan University | Xu D.,Hubei Provincial Key Laboratory of Developmentally Originated Disease | Bai J.,Wuhan University | Zhang L.,Wuhan University | And 6 more authors.
Toxicology Research | Year: 2015

Previous studies have indicated that the intrauterine growth retardation (IUGR) fetus is faced with a high susceptibility to adult metabolic syndrome (MS). Non-alcoholic simple fatty liver (NAFL) is considered to be the hepatic manifestation of MS. In the present study, we evaluated the susceptibility of high-fat diet-induced NAFL in female adult IUGR offspring rats, induced by prenatal nicotine exposure, and we further explored the underlying intrauterine programming mechanism for this phenomenon. The IUGR rat model was established by prenatal exposure to nicotine (2 mg kg-1 d-1), the liver tissues from female fetuses and female adult offspring fed with normal or high-fat diets were collected. The female adult offspring in the nicotine-exposed group showed low birth weights and postnatal catch-up growth, as well as severe NAFL under high-fat diets. Moreover, increased gene expression involved in the hepatic insulin-like growth factor 1 (IGF1) pathway, gluconeogenesis and lipid synthesis, and decreased gene expression of lipid output accompanied with elevated serum triglyceride levels, was observed. The female fetuses in the nicotine-exposed group showed down-regulated hepatic IGF1 pathways, and also exhibited similar patterns of increased gluconeogenesis, lipid synthesis and decreased lipid output to those in the adults. The present study demonstrates the intrauterine origin of increased susceptibility to high-fat diet-induced NAFL in female offspring rats by prenatal nicotine exposure, which is most likely mediated by "two intrauterine programming". That is, the first glucocorticoid-IGF1 axis programming induces postnatal catch-up growth, aggravates glucose and lipid metabolic disorders, and leads to an increased susceptibility to adult NAFL, while the second hepatic glucose and lipid metabolic programming enhances hepatic lipogenesis and reduces lipid oxidation and output, promoting NAFL. This journal is © The Royal Society of Chemistry 2015.

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