Angiotensin II-transient receptor potential channel C6 signaling pathway mediates podocyte injury

doi:10.3969/j.issn.2095-4344.2014.46.014

Abstract

Abstract:

BACKGROUND: Transient receptor potential channel C6 (TRPC6) is a new and important slit diaphragm-associated protein in podocytes involved in regulating glomerular filter function. Glomerular TRPC6 expression is closely associated with proteinuria in diabetic kidney disease.

OBJECTIVE: To investigate the expression of canonical TRPC6 in mouse podocytes induced by high glucose, and to explore the possible mechanism of diabetic kidney disease.

METHODS: Mouse podocyte cells were cultured and divided into normal glucose group (5.6 mmol/L D-glucose), normal control group (5.6 mmol/L D-glucose+25 mmol/L mannitol) and experimental groups which were in the environment of high glucose (30 mmol/L). The experimental groups included high glucose group, valsartan treatment groups (10^-⁵ mol/L) and U73122 control group (10 μmol/L U73122). After 48 hours, the expressions of mRNA and proteins of TRPC6, nephrin and angiotensin II (AngII) were detected respectively by real-time quantitative PCR and western blot analysis.

RESULTS AND CONCLUSION: Compared with the normal control group, the expressions of mRNA and proteins of TRPC6 and angiotensin II were markedly elevated in the high glucose group (P < 0.01), while the expressions of mRNA and proteins of nephrin were decreased (P < 0.01). The mRNA and proteins of TRPC6 and angiotensin II expressions were significantly down-regulated by valsartan (P < 0.05, P < 0.01), while the mRNA and protein expressions of nephrin were effectively up-regulated (P < 0.05). Compared with the high glucose group, the expressions of mRNA and proteins of TRPC6 and angiotensin II were ameliorated in the U73122 control group. The expressions of mRNA and proteins of TRPC6, nephrin and angiotensin II had no statistical significance between the normal control group and normal glucose group (P > 0.05). Angiotensin II-TRPC6 signaling pathway may mediate high glucose-induced podocyte injury, meanwhile it provides a new theoretical basis for the treatment of diabetic kidney disease, by which the angiotensin receptor blockers can protect podocytes in diabetic kidney disease.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

全文链接：

Key words: angiotensin II, podocytes, diabetes mellitus, TRPC cation channels

CLC Number:

R318

Yao Dan-dan, Ma Rui-xia, Zhai Li-hui, Li Zuo-lin, Li Zhen. Angiotensin II-transient receptor potential channel C6 signaling pathway mediates podocyte injury [J]. Chinese Journal of Tissue Engineering Research, 2014, 18(46): 7447-7451.

Figures/Tables 1

2.1 各组足细胞nephrin、TRPC6 mRNA表达 2.1.1 高糖对足细胞nephrin mRNA表达的影响与正常糖组相比，高糖组nephrin mRNA的表达量显著下降(P < 0.01)；渗透压对照组nephrin与正常糖组相比差异无显著性意义(P > 0.05)。见图1A。 2.1.2 高糖对足细胞TRPC6 mRNA表达的影响与正常糖组比较，高糖组TRPC6 mRNA表达量显著增加(P < 0.01)。见图1B。 2.1.3 血管紧张素受体阻断剂对高糖环境下足细胞 nephrin、TRPC6 mRNA表达的影响与高糖组相比，缬沙坦可以上调nephrin mRNA的表达，抑制TRPC6 mRNA 表达，差异有显著性意义(P < 0.05)。见图1A，B。 2.1.4 U73122对高糖环境下足细胞TRPC6 mRNA表达的影响与高糖组相比，高糖+U73122组TRPC6 mRNA表达显著下降(P < 0.05)。见图1B。 2.2 各组足细胞nephrin、血管紧张素Ⅱ、TRPC6蛋白表达的影响 Western blot检测结果见图1C。 2.2.1 高糖对足细胞nephrin蛋白表达的影响与PCR 结果一致，高糖组nephrin蛋白的表达量较正常组显著下降 (P < 0.01)；渗透压对照组nephrin蛋白表达量与正常组相比无显著性差异(P > 0.05)。见图2A。 2.2.2 高糖对足细胞血管紧张素Ⅱ、TRPC6蛋白表达的影响与正常组相比，高糖组血管紧张素Ⅱ、TRPC6蛋白表达量显著上调(P < 0.01)；高糖+U73122组血管紧张素Ⅱ、TRPC6表达较高糖组显著下降(P < 0.01)。渗透压对照组血管紧张素Ⅱ、TRPC6蛋白表达量与正常组相比差异无显著性意义(P > 0.05)。见图2B，C。 2.2.3 血管紧张素受体阻断剂对高糖环境下足细胞血管紧张素Ⅱ、nephrin、TRPC6蛋白表达的影响与高糖组相比，缬沙坦组nephrin蛋白表达量升高，而血管紧张素Ⅱ、TRPC6蛋白表达降低，差异有显著性意义(P < 0.01)。见图2A-C。 2.2.4 U73122对高糖环境下足细胞血管紧张素Ⅱ、TRPC6蛋白表达的影响与高糖组相比，U73122治疗组血管紧张素Ⅱ、TRPC6蛋白表达降低，差异有显著性意义 (P < 0.01)。见图2 A-C。"

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