Abundance of TRPC6 protein in glomerular mesangial cells is decreased by ROS and PKC in diabetes
Abundance of TRPC6 protein in glomerular mesangial cells is decreased by ROS and PKC in diabetes
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DOI：
10.1152/ajpcell.00014.2011
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发表时间：
2011-08-01
影响因子：
5.5
通讯作者：
Ma, Rong
中科院分区：
文献类型：
--
作者：
Graham, Sarabeth;Gorin, Yves;Ma, Rong
[10] Graham S，Gorin Y，Abboud HE，Ding M，Lee DY，Shi H，Ding Y，Ma R.糖尿病肾小球系膜细胞TRPC 6蛋白表达受ROS和PKC影响美国生理学杂志细胞生理学301：C304-C315，2011年。首次发表于2011年4月27日; doi：10.1152/ajpcell.00014.2011。本研究旨在探讨糖尿病诱导的典型瞬时受体电位6（TRPC 6）下调的机制，特别是活性氧（ROS）和蛋白激酶C（PKC）的作用。我们发现高糖（HG）显著降低了培养的系膜细胞（MCs）中TRPC 6蛋白的表达。TRPC 6蛋白在肾小球中也显著减少，但在从链脲佐菌素诱导的糖尿病大鼠分离的心脏或主动脉中没有。在培养的MC中，H2 O2以剂量和时间依赖的方式抑制TRPC 6蛋白的表达，这模仿了HG效应。过氧化氢酶和超氧化物歧化酶能够阻止HG对TRPC 6的抑制作用。在用tempol处理2周的糖尿病大鼠中也观察到在培养的细胞中观察到的抗氧化作用，其表现出肾小球中TRPC 6的保存。特异性敲除NADPH氧化酶的一个组分Nox 4，增加TRPC 6蛋白表达。此外，PKC激活剂佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA），而不是其类似物4 α-佛波醇12，13-二癸酸酯（4 α-PDD），抑制TRPC 6的表达，这种PMA效应不受过氧化氢酶的影响。此外，Go 6976，而不是LY 333531，减弱HG对TRPC 6表达的负面影响。Go 6976还抑制H2 O2对TRPC 6的作用。此外，无论是敲低TRPC 6或HG治疗显着降低ANG II刺激的MC收缩，和HG受损的MC收缩被拯救过表达的TRPC 6。这些结果表明，糖尿病高血糖通过NADPH氧化酶Nox 4-ROS-PKC途径下调MC中TRPC 6蛋白的表达，证明了糖尿病MC收缩受损的机制。
Graham S, Gorin Y, Abboud HE, Ding M, Lee DY, Shi H, Ding Y, Ma R. Abundance of TRPC6 protein in glomerular mesangial cells is decreased by ROS and PKC in diabetes. Am J Physiol Cell Physiol 301: C304-C315, 2011. First published April 27, 2011; doi: 10.1152/ajpcell.00014.2011.-The present study was performed to investigate the underlying mechanism, particularly the roles of reactive oxygen species (ROS) and protein kinase C (PKC), in the diabetes-induced canonical transient receptor potential 6 (TRPC6) downregulation. We found that high glucose (HG) significantly reduced TRPC6 protein expression in cultured mesangial cells (MCs). TRPC6 protein was also significantly reduced in the glomeruli but not in the heart or aorta isolated from streptozotocin-induced diabetic rats. In the cultured MCs, H2O2 suppressed TRPC6 protein expression in a dose-and time-dependent manner, which emulated the HG effect. Catalase as well as superoxide dismutase were able to prevent the inhibitory effect of HG on TRPC6. The antioxidant effect observed in cultured cells was also observed in diabetic rats treated with tempol for 2 wk, which exhibited a preservation of TRPC6 in the glomeruli. Specific knockdown of Nox4, a component of NADPH oxidase, increased TRPC6 protein expression. Furthermore, the PKC activator phorbol 12-myristate 13-acetate (PMA), but not its analog 4 alpha-phorbol 12, 13-didecanoate (4 alpha-PDD), suppressed TRPC6 expression, and this PMA effect was not affected by catalase. Moreover, Go6976, but not LY333531, attenuated the negative effect of HG on TRPC6 expression. Go6976 also inhibited H2O2 effect on TRPC6. Furthermore, either knockdown of TRPC6 or HG treatment significantly decreased ANG II-stimulated MC contraction, and the HG-impaired MC contraction was rescued by overexpression of TRPC6. These results suggest that hyperglycemia in diabetes downregulated TRPC6 protein expression in MCs through a NADPH oxidase Nox4-ROS-PKC pathway, proving a mechanism for impaired MC contraction in diabetes.