Sustained activation of autophagy and lipid accumulation in tubular epithelial cells (TECs) are both associated with the kidney fibrosis progression. Autophagy has been found involved in the lipid metabolism regulation through a bidirectional mechanism of inducing lipolysis as well as promoting lipid droplet formation. However, whether and how autophagy influences lipid accumulation in kidney fibrosis remain unclear. In the current study, we show that UUO-induced lipid accumulation in tubular cells was significantly reduced when the pharmacological inhibitor 3-MA or CQ was administrated both in vivo and in vitro. Of interest, colocalization of LDs and autophagosomes, as well as colocalization of LDs and lysosomes were undetected in UUO-induced fibrotic kidneys, although lysosome function remained robust, indicating the lipid accumulation is lipophagy-lysosome pathway independent. TGF-beta 1-induced lipid droplets formation in HK-2 cells were decreased when the Beclin-1 expression was silenced, implying that autophagy-upregulated lipid droplets formation is Beclin-1 dependent. Finally, CQ treatment of UUO-induced fibrotic kidneys reduced the expression of alpha-SMA and tubular cell apoptosis and rescued the expression of E-cadherin, which was associated with the ameliorated lipid deposition. Therefore, our work documented that autophagy promotes lipid droplet formation in TECs in a Beclin-1-dependent manner, which causes renal lipotoxicity and contributes to the progression of kidney fibrosis.
基金:
National Natural Science Foundation of China (NSFC)National Natural Science Foundation of China (NSFC) [81172793, 81370800]; National Key Technology R&D Program of ChinaNational Key Technology R&D Program [2011BAI10B04]; Independent Research Project of Wuhan University [2042014kf02]
第一作者单位:[1]Wuhan Univ, Dept Nephrol, Renmin Hosp, Wuhan, Hubei, Peoples R China[2]Huazhong Univ Sci & Technol, Dept Geriatr, Tongji Hosp, Tongji Med Coll, Wuhan, Hubei, Peoples R China
通讯作者:
推荐引用方式(GB/T 7714):
Yan Qi,Song Yuan,Zhang Lu,et al.Autophagy activation contributes to lipid accumulation in tubular epithelial cells during kidney fibrosis[J].CELL DEATH DISCOVERY.2018,4:doi:10.1038/s41420-018-0065-2.
APA:
Yan, Qi,Song, Yuan,Zhang, Lu,Chen, Zhaowei,Yang, Cheng...&Wang, Huiming.(2018).Autophagy activation contributes to lipid accumulation in tubular epithelial cells during kidney fibrosis.CELL DEATH DISCOVERY,4,
MLA:
Yan, Qi,et al."Autophagy activation contributes to lipid accumulation in tubular epithelial cells during kidney fibrosis".CELL DEATH DISCOVERY 4.(2018)