Abstract
Angiotensin II (Ang II) is a risk factor for the initiation and progression of chronic kidney disease (CKD), as elevated Ang II levels can lead to podocyte injury. However, there have been no studies on the role of Ang II in lipid metabolism or on podocyte injury caused by lipid dysfunction. Our study showed that Ang II induced lipid droplet (LD) accumulation and expression of the LD marker adipose differentiation-related protein (ADRP) in podocytes, and the extent of lipid deposition could be alleviated by losartan. Our study also demonstrated that Ang II increased the content of cholesterol in podocytes, which is an LD component, and this change was accompanied by decreased expression of the cholesterol efflux-related molecule ATP-binding cassette transporter-1 (ABCA1) and increased expression of the cholesterol uptake-related molecule LDL receptor (LDLR) and the cholesterol synthesis-related molecules sterol regulatory element-binding protein (SREBP1 and SREBP2) and 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR). Pretreating podocytes with methyl-β-cyclodextrin (CD), which induces cholesterol efflux, decreased Ang II-mediated cholesterol accumulation and Ang II-induced podocyte apoptosis and maintained the podocyte cytoskeleton and spreading. These results suggested that Ang II induced podocyte cholesterol accumulation by regulating the expression of cholesterol metabolism-related molecules and that the subsequent cholesterol metabolism dysfunction resulted in podocyte injury.