VERY-LOW-DENSITY LIPOPROTEIN AND OXIDIZED VERY-LOW-DENSITY LIPOPROTEIN INDUCE MONOCYTE CHEMOTACTIC PROTEIN-1 IN RABBIT AORTIC SMOOTH-MUSCLECELLS

Objective. To understand whether very low density lipoprotein (VLDL) a nd oxidatively modified very low density lipoprotein (OX-VLDL) can sti mulate vascular smooth muscle cells (SMCs) to express high level of mo nocyte chemotactic protein 1 (MCP-1) mRNA. Methods. LDL and VLDL were isolated from normal blood donors by density gradient ultracentrifugat ion and oxidatively modified by adding CuCl2 and incubation at 37 degr ees C for 24 hours. Rabbit aortic SMCs were cultured by a substrate-at tached explant method, and their total RNA was extracted by guanidiniu m isothiocyanate method. The expression of MCP-1 mRNA in SMCs was exam ined by dot blotting analysis using a probe of gamma-P-22-end-labeled 35-mer oligonucleotide. Results. Dot blotting analysis showed that cul tured SMCs can express MCP-1 mRNA and the level of MCP-I mRNA was incr eased significantly in SMCs after 24-hour coculture with VLDL (6-fold) and OX-VLDL (20-fold). Conclusions. VLDL and OX-VLDL both can induce MCP-1 mRNA expression in cultured rabbit aortic SMCs and the latter is more effective than the former.