Role of caveolinª²1 in SRª²AI mediated formation of foam cells derived from macrophages

    WANG Rongª²Rong£¬ZHU Bingª²Yang£¬YAN Pengª²Ke£¬LIAO Duanª²Fang

    Institute of Pharmacology, Nanhua University, Hengyang 421001, China

    ¡¾Abstract¡¿ AIM£º To investigate the role of caveolinª²1 in scavenger receptor ai (SRª²AI) mediated formation of macrophageª²derived foam cells induced by oxidized lowª²density lipoprotein (oxª²LDL). METHODS: RAW 264.7 macrophages were treated with 75 mg/L oxª²LDL for different hours. Next, macrophages were preª²treated with SB202190 and SRª²AI antisense oligonucleotides before 75 mg/L oxª²LDL treatment for 24 h. Western blot analysis was used to detect protein expression. High performance liquid chromatography (HLPC) analysis was performed to determine the cellular cholesterol content. Oil red O staining was used to show the lipid droplets in foam cells. RESULTS: Western blot analysis showed that SRª²AI expression increased with 75 mg/L oxª²LDL treatment for 12, 24 and 48 h. 75 mg/L oxª²LDL treatment for 6, 12, 24, 48 and 96 h decreased the expression of caveolinª²1. When oxª²LDL treatment was over 24 h, descended expression of caveolinª²1 in macrophages was observed and lasted for 96 h. Preª²treatment of SB202190 and SRª²AI antisense oligonucleotides decreased the expression of SRª²AI and increased the expression of caveolinª²1. Meanwhile, the cellular cholesterol content was also decreased (P<0.01 vs oxª²LDL treatment groups). Oil red O staining showed that the SB202190 preª²treatment group and SRª²AI antisense oligonucleotides group formed less lipid droplets than oxª²LDL treatment group did. CONCLUSION: There appears a negative relationship between caveolinª²1 and SRª²AI during the accumulation of lipidª²laden foam cells. ......