[Effects of oxidized low-density lipoprotein on expression of type A scavenger receptor in human mesangial cells].

OBJECTIVE: To explore the regulational effect of oxidized low-density lipoprotein (Ox-LDL) on expression of type A scavenger receptor (SR-A) in human mesangial cells (HMC). METHODS: HMC line (HMCL) with high expression of SR-A (HMCL-SRA) was established after stable transfection of expressive vector with cDNA encoding SR-A. Uptake of Ox-LDL by HMCL was evaluated using Oil Red "O" staining. SR-A mRNA expression was examined using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: More uptake of Ox-LDL was observed in the HMCL-SRA than that in the untransfected HMCL. Ox-LDL could induce SR-A mRNA expression in HMC in a dose-dependent manner, and reached a peak level after 24 h of stimulation. After 24 h of stimulation with Ox-LDL at the dose of 10, 50 and 100 micrograms/ml, SR-A mRNA expression was up-regulated to 1.35, 1.83 and 2.30-fold of controls, respectively. However, LDL had no effect on the expression of SR-A. CONCLUSIONS: It suggests that SR-A be a major binding receptor to uptake Ox-LDL in HMC. Ox-LDL may promote the progression of chronic renal diseases through up-regulation of SR-A.