ABSTRACT
Objective To explore the mechanisms of integrin β1 on connective tissue growth factor(CTGF)-induced proliferation,migration,change of cytoskeleton of pulmonary arterial smooth muscle cell(PASMC) in vitro,and to investigate the effects of CTGF-integrin β1 signal pathway on pulmonary vascular remodeling in pulmonary arterial hypertension (PAH).Methods Pulmonary artery smooth muscle cells of SD rats were cultured in vitro.WST-1 assay was used to detect the effects of anti-integrin β1 antibody on CTGF-induced proliferation of PASMC.Transwell chambers were used to observe the effects of anti-integrin β1 antibody on CTGF-induced migration of PASMC.The cytoskeletal rearrangement was observed with coomassie brilliant blue R250 staining and Confocal Lasar Scanning Microscopy (CLSM).Results Different concentration of anti-integrin β1 antibody could inhibit the proliferation of PASMC induced by CTGF,which presents concentration dependent pattern (P ＜ 0.05).The higher the concentration of anti-integrin β1 antibody,the more severity the proliferation of PASMC induced by CTGF was inhibited.and inhibition rate of PASMC proliferation was the highest at 72 hours.Anti-integrin β1 antibody(15 mg/L) decreased significantly the number of PASMC passing through Transwell induced by CTGF,compared with CTGF group (P ＜ 0.01).Meanwhile,antiintegrin β1 antibody could change cytoskeletal rearrangement of PASMC induced by CTGF.Conclusions Integrin β1mediates the proliferation,migration,cytoskeletal rearrangement of PASMC induced by CTGF.The CTGF-integrin β1signal pathway may play a key role in proliferation,migration,cytoskeletal rearrangement PASMC.
ABSTRACT
Objective To explore the effects of the extracellular regulated protein kinase’s (ERK1/2) inhibitor PD98059 and ino-sitol triphosphate kinase (PI3K/PKB) signaling pathway’s inhibitor LY294002 on extracellular matrix (ECM) deposition in pulmonary arterial smooth muscle cells (PASMCs) stimulated by connective tissue growth factor (CTGF). Methods PASMCs of SD rat were cul-tured in vitro. The PASMCs were divided into control group, CTGF group, CP (CTGF+PD98059) group, CL (CTGF+LY294002) group and CPL (CTGF+PD98059+LY294002) group. Real-time lfuorescent quantitative RT-PCR was used to detect the expression of colla-gen III and ifbronectin mRNA of PASMCs, and the expression of collagenШprotein of PASMCs was detected by immunohistochem-istry and western-blot. Results The expressions of collagenШand ifbronectin mRNA of PASMCs stimulated with CTGF (50 ng/ml) for 48 h were signiifcantly higher than those in control group, and the collagen proteinШof PASMCs was decreased signiifcantly after stimulation with CTGF (50 ng/ml) for 72 h (P<0.05). The expressions of collagenШand ifbronectin mRNA in PASMCs cultured with PD98059 (20μmol/L) and/or LY294002 (10μmol/L) for 48 h was signiifcantly lower than those in CTGF group (P<0.05). The collagen proteinШin PASMCs cultured with PD98059 (20μmol/L) and/or LY294002 (10μmol/L) for 72 h was increased (P<0.05). The expres-sions of collagenШand ifbronectin mRNA of PASMCs stimulated with both PD98059 and LY294002 were more signiifcant. Conclu-sions CTGF may increase the expression of collagenШand ifbronectin mRNA in PASMCs, which may contribute to the deposition of ECM in PASMCs during pulmonary vascular remodeling. PD98059 and LY294002 may repress ERK1/2 and PI3K/PKB signaling pathways and interfere with the biological effect of CTGF.
ABSTRACT
Many cardiovascular diseases, such as pulmonary hypertension, atherosclerotic plaque formation and restenosis after angioplasty, are charaterized by vascular remodeling resulting from migration and proliferation of vascular smooth muscle cells. Integin receptors can activate the expression of related genes through the corresponding signal pathway, and lead to vascular smooth muscle cell' s proliferation and migration and other biological behavioral change, which may be a new hotspot of pathogenesis and intervention of vascular remodeling.