Angiotensin II induces nephrin dephosphorylation and podocyte injury: role of caveolin-1.
Angiotensin II induces nephrin dephosphorylation and podocyte injury: role of caveolin-1.
复制标题
血管紧张素II诱导肾素去磷酸化和足细胞损伤：小窝蛋白-1的作用。
DOI：
10.1016/j.cellsig.2011.09.022
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发表时间：
2012-02
影响因子：
4.8
通讯作者：
Ding G
中科院分区：
文献类型：
--
作者：
Ren Z;Liang W;Chen C;Yang H;Singhal PC;Ding G
Nephrin 是足细胞狭缝隔膜 (SD) 的重要结构和信号分子，已被认为有助于血管紧张素 II (Ang II) 诱导的足细胞损伤。 Caveolin-1 已被证明在信号转导中发挥着至关重要的作用。在本研究中，我们评估了 Caveolin-1 在 Ang II 诱导的足细胞去氧肾上腺素磷酸化中的作用。 Wistar大鼠接受Ang II (400 ng/kg/min)或生理盐水(通过皮下渗透微型泵，对照)，施用媒介物或替米沙坦(3 mg/kg/min)，持续14或28天。实验结束时测量血压、24小时尿白蛋白和血清生化特征。通过光学和电子显微镜评估肾组织形态学。在体外，将培养的小鼠足细胞暴露于经过或不经过氯沙坦 (10−5 M) 预处理的 Ang II (10−6 M) 不同时间段。通过蛋白质印迹和免疫荧光分析 Nephrin 和 Caveolin-1 的表达及其磷酸化。通过蔗糖密度梯度离心分离小凹膜组分，然后使用蛋白质印迹和免疫共沉淀评估 Ang II 1 型受体 (AT1)、去氧肾上腺素、C 末端 Src 激酶 (Csk) 和 Caveolin-1 之间的分布和相互作用。通过使用 Hoechst-33342 进行细胞核染色来评估足细胞凋亡。与对照组大鼠相比，接受 Ang II 治疗的大鼠表现出去氧肾上腺素磷酸化减弱，但肾小球/足细胞损伤和蛋白尿增强。在对照条件下，足细胞表现出丰富的 Caveolin-1 表达，但仅表达低水平的磷酸部分。尽管如此，Ang II 刺激 Caveolin-1 磷酸化，但总蛋白表达没有任何变化。 Nephrin 和 Caveolin-1 共定位于小凹部分。 AT1 受体和 Csk 被转移到小凹部分，并在 Ang II 刺激后与小凹蛋白-1 发生相互作用。 Caveolin-1 质粒 (pEGFPC3-cav-1) 的转染显着增加 Ang II 诱导的去磷酸化和足细胞凋亡。此外，敲除caveolin-1表达（使用siRNA）可抑制去氧肾上腺素去磷酸化并阻止Ang II诱导的足细胞凋亡。这些发现表明，Ang II 通过 Caveolin-1 依赖性机制诱导去磷酸化和足细胞损伤。
Nephrin, an important structural and signal molecule of podocyte slit-diaphragm (SD), has been suggested to contribute to the angiotensin II (Ang II)-induced podocyte injury. Caveolin-1 has been demonstrated to play a crucial role in signaling transduction. In the present study, we evaluated the role of caveolin-1 in Ang II-induced nephrin phosphorylation in podocytes. Wistar rats-receiving either Ang II (400 ng/kg/min) or normal saline (via subcutaneous osmotic mini-pumps, control) were administered either vehicle or telmisartan (3 mg/kg/min) for 14 or 28 days. Blood pressure, 24-hour urinary albumin and serum biochemical profile were measured at the end of the experimental period. Renal histomorphology was evaluated through light and electron microscopy. In vitro, cultured murine podocytes were exposed to Ang II (10−6 M) pretreated with or without losartan (10−5 M) for variable time periods. Nephrin and caveolin-1 expression and their phosphorylation were analyzed by Western-blotting and immunofluorescence. Caveolar membrane fractions were isolated by sucrose density gradient centrifugation, and then the distribution and interactions between Ang II type 1 receptor (AT1), nephrin, C-terminal Src kinase (Csk) and caveolin-1 were evaluated using Western-blotting and co-immunoprecipitation. Podocyte apoptosis was evaluated by cell nucleus staining with Hoechst-33342. Ang II-receiving rats displayed diminished phosphorylation of nephrin but enhanced glomerular/podocyte injury and proteinuria when compared to control rats. Under control conditions, podocyte displayed expression of caveolin-1 in abundance but only a low level of phospho moiety. Nonetheless, Ang II stimulated caveolin-1 phosphorylation without any change in total protein expression. Nephrin and caveolin-1 were co-localized in caveolae fractions. AT1 receptors and Csk were moved to caveolae fractions and had an interaction with caveolin-1 after the stimulation with Ang II. Transfection of caveolin-1 plasmid (pEGFPC3-cav-1) significantly increased Ang II-induced nephrin dephosphorylation and podocyte apoptosis. Furthermore, knockdown of caveolin-1 expression (using siRNA) inhibited nephrin dephosphorylation and prevented Ang II-induced podocyte apoptosis. These findings indicate that Ang II induces nephrin dephosphorylation and podocyte injury through a caveolin-1-dependent mechanism.
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影响因子：
15.9
作者：
Verma, R;Kovari, I;Holzman, LB
通讯作者：
Holzman, LB
影响因子：
6
作者：
Suzuki, Koichi;Han, Gi Dong;Kawachi, Hiroshi
通讯作者：
Kawachi, Hiroshi
影响因子：
4.2
作者：
Jia, Junya;Ding, Guohua;Singhal, Pravin C.
通讯作者：
Singhal, Pravin C.
影响因子：
6.1
作者：
Wei, Changli;Reiser, Jochen
通讯作者：
Reiser, Jochen
DOI：
10.1152/ajprenal.00266.2007
发表时间：
2008-04-01
影响因子：
4.2
作者：
Durvasula, Raghu V.;Shankland, Stuart J.
通讯作者：
Shankland, Stuart J.