Objectives To investigate the effects of angiotensinII (AngII) and angiotensin-(1-7) [Ang-(1-7)] on scavenger receptor class B type1 (SR-BI), ATP-binding cassette transporter A1 (ABCA1) and cholesterol efflux in THP-1 derived foam cells.
Methods Human monocytic cell line (THP-1) was induced intomacrophages by100 nmol/L phorbol myristate acetate (PMA) for 48h, and treated with ox-LDL to construct the foam cells, then were randomly allocated into five groups: control group, AngII group,Ang-(1-7) group, Ang-(1-7) + AngII groupand AngII + Ang-(1-7) + A-779 group. Them RNA and protein expression of SR-BI, ABCA1were determinded by RT-PCR and Westernblot, the intracellular cholesterol efflux rate was detected by liquid scintillator.
Results Compared with the control group, AngII decreasedSR-BI andABCA1 in both protein and mRNA, and inhibited the cholesterol efflux (P < 0.05). Those effects could be attenuated by cotreated with Ang-(1-7)(P < 0.05). However when incubated with A-799, an inhibitor of Ang-(1-7), the effects ofAng-(1-7) on promoting the expression of SR-BI, ABCA1 and the cholesterol efflux were significantly abolished (P < 0.05).
Conclusions In THP-1 derived foam cells, Ang-(1-7) via its specific receptor MAS attenuates the reduction of the expression of SR-BI and ABCA1 induced by AngII, and increases the cholesterol efflux.