血管肽对离体大鼠血管平滑肌细胞增殖和c-myb mRNA表达的影响

Effects of angiopeptin on expression of c-myb mRNA in rat vascular smooth muscle cells

目的 观察了血管肽 (angiopeptim ,AP)对血小板源性生长因子刺激下离体大鼠胸主动脉血管平滑肌细胞 (VSMC)增殖和c mybmRNA表达的影响 ,从分子生物学水平探讨其抗增殖作用机制。方法 采用细胞计数确定VSMC增殖状态。以Nothern印迹法测定c mybmRNA表达水平。结果 各组细胞计数分别为 (5 45± 0 5 7)× 10 4,对照组 ;(4 12± 0 13)× 10 4,30nmol L ;(3 13± 0 2 0 )× 10 4,6 0nmol L和 (2 0 3± 0 0 5 )× 10 4,12 0nmol L ;(q =10 5 0 ,10 32和 2 7 0 1,P <0 0 1)。抑制率分别为 2 9% ,5 2 %和 77%。其对VSMCc mybmRNA表达的抑制也具剂量依赖性。c mybmRNA GAPDH比值分别为1 12± 0 0 2 (对照组 ) ;0 6 1± 0 0 1,30nmol L ;0 34± 0 0 1,6 0nmol L和 0 16± 0 0 1,12 0nmol L ;q =39 2 3,6 0 0 0和 73 85 ,P <0 0 1)。结论 血管肽显著抑制VSMC增殖及c myb原癌基因表达 ,作用呈剂量依赖性。提示AP抗增殖作用与抑制晚期生长调节基因表达有关。

Oncogenes play an important role in cell growth and differentiation Angiopeptin (AP) has been shown to be a potent antiproliferative agent for various cell types The mechanism of AP on the VSMC proliferation is unclear The aim of this study was to analyze the effects of AP on proliferation and expression of c-myb protooncogene in cultured rat VSMC treated with platelet-derived growth factor (PDGF) Methods Cell proliferation was determined by cell counting The expression of c-myb mRNA of VSMC was detected by Northern blot Results AP produced a dose-dependent inhibition of VSMC proliferation compared with control group The number of VSMC were (5 45±0 57)×10 4 (for control group, ±s ); (4 12±0 13)×10 4, 30 nmol/L; (3 13±0 20)×10 4, 60 nmol/L; and (2 03±0 05)×10 4, 120 nmol/L;( q =10 50, 10 32 and 27 01; P <0 01) respectively The inhibitory rates were in turn 29%, 52% and 77%, compared with control group The c-myb mRNA expression of VSMC was also inhibited by AP in a dose-dependent manner The relative densitometric units were 1 12±0 02 (for control); 0 61±0 01, 30 nmol/L; 0 34±0 01, 60 nmol/L and 0 16±0 01, 120 nmol/L; ( q =39 23, 60 00, and 73 85; P <0 01) Conclusions AP strongly inhibits both VSMC proliferation and c-myb mRNA expression, suggesting that the mechanism of AP on VSMC proliferation is related to suppressing the late growth regulated gene expression