Endothelial autophagy deficiency induces IL6 - dependent endothelial mesenchymal transition and organ fibrosis.

Macroautophagy/autophagy plays a vital role in the homeostasis of diverse cell types. Vascular endothelial cells contribute to vascular health and play a unique role in vascular biology. Here, we demonstrated that autophagy defects in endothelial cells induced IL6 (interleukin 6)-dependent endothelial-to-mesenchymal transition (EndMT) and organ fibrosis with metabolic defects in mice. Inhibition of autophagy, either by a specific inhibitor or small interfering RNA (siRNA) for ATG5 (autophagy related 5), in human microvascular endothelial cells (HMVECs) induced EndMT. The IL6 level was significantly higher in ATG5 siRNA-transfected HMVECs culture medium compared with the control HMVECs culture medium, and neutralization of IL6 by a specific antibody completely inhibited EndMT in ATG5 siRNA-transfected HMVECs. Similar to the in vitro data, endothelial-specific atg5 knockout mice (Atg5 Endo; Cdh5-Cre Atg5 flox/flox mice) displayed both EndMT-associated kidney and heart fibrosis when compared to littermate controls. The plasma level of IL6 was higher in Atg5 Endo compared to that of control mice, and fibrosis was accelerated in Atg5 Endo treated with a HFD; neutralization of IL6 by a specific antibody inhibited EndMT and fibrosis in HFD-fed Atg5 Endo associated with the amelioration of metabolic defects. These results revealed the essential role of autophagy in endothelial cell integrity and revealed that the disruption of endothelial autophagy could lead to significant pathological IL6-dependent EndMT and organ fibrosis. Abbreviations: 3-MA: 3-methyladenine; ATG5: autophagy related 5; EndMT: endothelial-to-mesenchymal transition; HES: hematoxylin and eosin stain; HFD: high-fat diet; HMVECs: human microvascular endothelial cells; IFNG: interferon gamma; IL6: interleukin 6; MTS: Masson's trichrome staining; NFD: normal-fat diet; siRNA: small interfering RNA; SMAD3: SMAD family member 3; TGFB: transforming growth factor ß; TNF: tumor necrosis factor; VEGFA: vascular endothelial growth factor A.

Effect of niaoduqing in combination with telmisartan on the diabetic nephropathy in rats / 实用医学杂志

Objective To investigate the effect of Niaoduqing combined with Telmisartan on the diabetic nephropathy in rats. Methods Forty female Wistar rats were randomly divided into the normal control group ( NC ) , the diabetic nephropathy in the control group ( DM ) , the uremic clearance group ( ND ) , and the combination group (LH). Rats in the DM, ND, LH groups were used to establish the diabetic nephropathy model. Rats in each group received the corresponding drugs. Twelve weeks later, the interactions among angiotensin receptor and adiponectin receptor were detected by co-immunoprecipitation assay. Western blot was performed to detect the expression of MCP-1, TGF-βto reveal the injury of the renal tubular interstitial. Results (1)Exogenous co-immunoprecipitation assay indicated that AdipoR1 and AT1, AT2 can form dimerization. Levels of AdipoR1-AT1, AdipoR2-AT2 dimerization were incresaed in the DM group compared with those in the NC group, but were decreased in the ND group and the LH group. (2)MCP-1 and TGF-βprotein expression were increased in the DM group compared with the normal control group (P < 0.05), but were decreased in the ND group and the LH group (P<0.05, respectively). Conclusion Niaoduqing combined with Telmisartan can significantly inhibit the expression of MCP-1 and TGF-βto relieve the renal tubular interstitial injury in rats with diabetic nephropathy. This protective mechanism may associated with the decrease of the dimerizations of AdipoRs and ATs.

Effect of telmisartan on the expression of urate transporter protein in the renal tubule epithelial cells / 中华肾脏病杂志

Objective To explore the protective effect and underlying mechanism of telmisartan on hyperuricemic nephropathy.Methods (1)High level of uric acid (600 μmol/L) and telmisartan in different concentrations (10nmol/L,100 nmol/L,1000 nmol/L,10000 nmol/L) were added to renal tubule epithelial cells and cultured for 48 h,the expression of UAT,TGF-β1 and α-SMA were detected by Real-time PCR,RT-PCR,Western blotting or cell immunofluorescence.(2) Wister rats were randomly divided into normal control group(Con),high uric acid group (HU),and telmisartan treatment group (Tel).Four weeks later,Scr,BUN and serum uric acid of the rats were detected.The expression of UAT in rat kidney was detected by Western blotting.Results (1)In vitro,compared to control group,high uric acid (600 μmol/L) inhibited the expression of UAT (P ＜ 0.01),and the inhibition could be alleviated by telmisartan; Telmisartan inhibited the upregulation of TGF-β1 and α-SMA induced by high uric acid(all P ＜ 0.05); (2)In vivo,compared to high uric acid group rats,telmisartan group rats had significantly reduced serum uric acid levels (189.9 μmol/L vs 204.5 μmol/L,P＜0.05),upregulated UAT and downregulated TGF-β1 expression in rat kidney (all P＜ 0.05).Conclusion Telmisartan significantly inhibits the upregulation of TGF-β1 and α-SMA induced by uricemia,which may prevent kidney from fibrosis.The protect effect of telmisartan may be related to the upregulation of UAT.

Angiotensin Ⅱ induces podocyte c-Abl expression change / 中华肾脏病杂志

ObjectiveTo evaluate the effects of angiotensin Ⅱ (Ang Ⅱ )infusion on renal c-Abl expression in vivo,and on podocyte c-Abl expression change in cultured mouse podocytes.Methods Twenty four male Sprague-Dawley rats (Group C,D,E and F) were assigned to receive Ang Ⅱ(400 ng· kg-1 min-1) by osmotic minipump and of which 12 rats (Group D and F) were assigned to receive telmisartan (3 mg·kg-1·d-1),six rats received normal saline(Group B),and six rats were used as normal control(Group A).Animals were sacrificed at day 14 (Group C and D),day 28 (Group E and F) respectively.Conditionally immortalized mouse podocytes were used in vitro.Podocytes were studied 2 weeks after thermoswitching from 33℃ to 37℃.Cells were fetal bovine serum(FBS) starved for at least 12 hours prior to stimulation.The cultured podocytes were treated withAngⅡdosesranging from10 -9 mol/L to10 -6 mol/L andfor differenthours.Expression of renal and podocytes c-Abl was examined by immunofluorescence staining,real-time PCR and Western blotting.Results(1) Distribution of c-Abl expression was mainly in the cytoplasm and nuclear of the podocytes in vivo and in vitro. (2) Expressions of c-Abl mRNA and protein wereincreasedinAng Ⅱ-infusedratpodocytesandAng Ⅱ-inducedculturedmouse podocytes(P＜0.05),and the effects of Ang Ⅱ were dose-dependent and time-dependent in vitro.Conclusion There are c-Abl mRNA and protein expression in podocytes,and c-Abl may play a critical role in the pathogenesis of Ang Ⅱ -induced podocyte injury.