摘要
Angiotensin II (Ang II) is a key mediator of chronic kidney disease, in which epithelial-mesenchymal transition (EMT) is a critical process mediated by the TGFβ/Smad signalling pathway. The present study examined the specific role of Smads in Ang II-induced EMT in vitro and in vivo. We found that Ang II signalled through the receptor of AT1, not AT2, to activate Smad2/3 and induce EMT in a normal rat tubular epithelial cell line (NRK52E). Activation of Smads by Ang II was attributed to degradation of an inhibitory Smad7, which was mediated by the AT1-Smurf2-dependent ubiquitin degradation mechanism because blockade of AT1 receptor or knockdown of Smurf2 inhibited Smad7 loss, thereby reducing Smad2/3 activation and EMT in response to Ang II. In contrast, over-expression of Smad7 inhibited Ang II-induced Smad2/3 activation and EMT in NRK52E cells and in a rat model of remnant kidney disease. Moreover, knockdown of Smad3, not Smad2, attenuated Ang II-induced EMT. In conclusion, Ang II activates Smad signalling to induce EMT, which is mediated by a loss of Smad7 through the AT1-Smurf2-dependent ubiquitin degradation pathway. Smad3, but not Smad2, may be a mediator of EMT, while Smad7 may play a protective role in EMT in response to Ang II.
原文 | 英語 |
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頁(從 - 到) | 390-401 |
頁數 | 12 |
期刊 | Journal of Pathology |
卷 | 221 |
發行號 | 4 |
DOIs | |
出版狀態 | 已發佈 - 8月 2010 |
ASJC Scopus subject areas
- 病理學與法醫學