Zhao Bo, Yang He, Zhang Rui, Sun Hui, Liao Chang, Xu Jia, Meng Kexin, Jiao Jundong
Department of Nephrology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China; Department of Nephrology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
Department of Nephrology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
Biochem Biophys Res Commun. 2015 May 29;461(2):413-20. doi: 10.1016/j.bbrc.2015.04.054. Epub 2015 Apr 18.
Increasing evidence suggests that ischemia and hypoxia serve important functions in the development of renal diseases. However, the underlying mechanism of ischemic injury has not been fully understood. In this study, we found that renal ischemia-reperfusion injury induced podocyte effacement and the upregulation of TRPC6 mRNA and protein expression. In in vitro experiments, oxygen glucose deprivation (OGD) treatment enhanced the expression of TRPC6 and TRPC6-dependent Ca(2+) influx. TRPC6 knockdown by siRNA interference attenuated the OGD-induced [Ca(2+)]i and actin assembly. OGD treatment also increased ROS production. Furthermore, inhibition of ROS activity by N-acetyl-l-cysteine (NAC) eliminated the OGD-induced increase in TRPC6 expression and Ca(2+) influx. H2O2 treatment, which results in oxidative stress, also increased TRPC6 expression and Ca(2+) influx. We conclude that TRPC6 upregulation is involved in Ca(2+) signaling and actin reorganization in podocytes after OGD. These findings provide new insight into the mechanisms underlying the cellular response of podocytes to ischemic injury.
越来越多的证据表明,缺血和缺氧在肾脏疾病的发展中发挥着重要作用。然而,缺血性损伤的潜在机制尚未完全明确。在本研究中,我们发现肾缺血再灌注损伤可导致足细胞足突消失以及瞬时受体电位通道6(TRPC6)mRNA和蛋白表达上调。在体外实验中,氧糖剥夺(OGD)处理可增强TRPC6的表达以及依赖TRPC6的钙离子内流。通过小干扰RNA(siRNA)干扰敲低TRPC6可减弱OGD诱导的细胞内钙离子浓度([Ca(2+)]i)升高和肌动蛋白组装。OGD处理还可增加活性氧(ROS)的产生。此外,用N-乙酰半胱氨酸(NAC)抑制ROS活性可消除OGD诱导的TRPC6表达增加和钙离子内流。导致氧化应激的过氧化氢(H2O2)处理也可增加TRPC6表达和钙离子内流。我们得出结论,TRPC6上调参与了OGD后足细胞内的钙离子信号传导和肌动蛋白重组。这些发现为足细胞对缺血性损伤的细胞反应机制提供了新的见解。