Biblioteca Virtual en Salud

Objective To investigate the effect of the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase on Toll-like receptor 4 (TLR4)-mediated proinflammatory phenotype of cultured vascular smooth muscle cells (VSMCs) in mice.Methods NADPH oxidase agonist platelet-derived growth factorBB (PDGF-BB) and inhibitor apocynin were used respectively to treat cultured VSMCs from C57BL/6J and TLR4-/-mice.The fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate was used to detect the reactive oxygen species (ROS) level in VSMCs.An enzyme-linked immunosorbent assay was used to detect the expressions of interleukin (IL)-6,IL-1β,and tumor necrosis factor-α (TNF-α) in VSMCs.Tetrazolium blue staining and Boyden chamber assay were used to detect the proliferation and migration of VSMC.Results The ROS levels were increased in VSMCs both from C57BL/6J and TLR4-/-mice after PDGF-BB treatment,and this could be inhibited by apocynin.PDGF-BB pretreatment significantly upregulated the expressions of IL-6 (52.69 ±3.49 ng/ml vs.35.04 ±2.74 ng/ml; P =0.001),IL-1β (79.68 ±2.33 ng/ml vs.62.38 ±0.54 ng/ml;P=0.000),and TNF-α (218.35± 5.42 ng/mlvs.124.74± 4.59 ng/ml; P=0.000) in VSMCs from C57BL/6J mice,and the abilities of proliferation (1.69 ± 0.53 vs.1.04 ± 0.40; P =0.000) and migration (42.11 ±4.05 vs.1.69 ± 0.53; P =0.000) were increased significantly; apocynin pretreatment significantly inhibit the expressions of IL-6 (42.11 ± 4.05 ng/ml vs.52.69 ± 3.49 ng/ml; P =0.010),IL-1β (67.57 ± 1.36 ng/ml vs.79.68 ±2.33 ng/ml; P =0.000) and TNF-α (156.18 ± 6.98 ng/ml vs.218.35 ± 5.42 ng/ml;P =0.000),as well as proliferation (1.23 ±0.42 vs.1.69 ±0.53; P =0.000) and migration (42.11 ±4.05 vs.52.69 ± 3.49; P =0.000).While there were no significant changes in the expressions of IL-6,IL-1β,and TNF-α in VSMCs from TLR4-/-mice after PDGF-BB and apocynin pretreatment.Conclusions NADPH oxidase-derived ROS involved in the TLR4-mediated VSMC inflammatory phenotype as well as proliferation and migration,which may be the important mechanisms of its influencing on the occurrence and development of atherosclerosis.