title: Advanced glycation end products upregulate angiopoietin-like protein 4 expression by activating the renin-angiotensin system in endothelial cells.
abstract: The aim of the present study was to investigate the effects of advanced glycation end products (AGEs) on the expression of angiopoietin-like protein 4 (ANGPTL4) and the mechanisms of the effects in endothelial cells. Endothelial cells were incubated with various concentrations of AGEs for 24 h and the expression of ANGPTL4 was detected by quantitative polymerase chain reaction and western blot analysis. The concentration of angiotensin II (Ang II) in conditioned media and cell lysates was measured by enzyme-linked immunosorbent assays. Fluorescein isothiocyanate-labeled dextran filtration assays and transendothelial electrical resistance were performed to evaluate endothelial permeability. AGEs (80 µg/ml) increased the expression of ANGPTL4 and the levels of Ang II (P<0.05). Incubation with AGEs also resulted in a significant increase in endothelial permeability (P<0.05). However, pretreatment with the Ang II receptor blocker losartan (10-5M) reduced the effects of AGEs (P<0.05). AGEs upregulated the expression ofANGPTL4by activating a local renin-angiotensin system in endothelial cells. This may be a new mechanism by which AGEs increase endothelial permeability.
authors.affiliation: Department of Cardiovascular, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Zhenda
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Nephrology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Cailian
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Department of Cardiovascular, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Ruimin
authors.initials: R
authors.lastname: Dong
authors.affiliation: Department of Nephrology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Cardiovascular, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Xiong
authors.affiliation: Department of Cardiovascular, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Xiaoxian
authors.initials: X
authors.lastname: Qian
authors.affiliation: Department of Cardiovascular, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
keywords: advanced glycation end products; angiopoietin-like protein 4; endothelial cells; renin-angiotensin system