中文摘要：

目的：探讨ERK通路是否参与TGF-β／Smad通路诱导的血管平滑肌细胞增殖及可能的分子机制。方法：原代培养大鼠胸主动脉平滑肌细胞，细胞分4组：（1）对照组；（2）TGF-β1组；（3）ERK阻断剂（PD98059）组；（4）TGF—β1＋ERK阻断剂（PD98059）组。MTT法测细胞的增殖活性，Westernblotting法检测VSMCs中细胞内核增殖抗原（PCNA）、Smad2／3、ERK1／2、Smad7蛋白表达及相关磷酸化蛋白含量，RT—PCR方法测VSMCs中Smad2、3、7mRNA的表达。结果：（1）各组PCNA蛋白表达和MTT法测得A值均低于对照组（P〈0．05），TGF—β1＋ERK阻断剂组与TGF—β1组相比无显著差异。（2）与对照组相比，TGF—β1组p—Smad2／3、p—ERK1／2蛋白含量和Smad7蛋白表达增高（P〈0．05），ERK阻断剂组则明显降低（P〈0．05）；与TGF—β1组比，TGF—β1＋ERK阻断剂组降低（P〈0．05）。各组间Smad2／3、ERK1／2蛋白表达无显著差异。（3）与对照组相比，TGF—β1组Smad7mRNA表达增高（P〈0．05），ERK阻断剂组和TGF—β1＋ERK阻断剂组降低（P〈0．05）；与TGF—β1组比，TGF—β1＋ERK阻断剂组表达降低（P〈0．05）。各组内VSMCs的Smad2、Smad3mRNA表达无显著差异。结论：（1）TGF—β1诱导的Smad2／3蛋白磷酸化依赖ERK通路激活，但对TGF—β1的抑制平滑肌细胞增殖的作用无影响，可能有其它信号通路参与此过程。（2）ERK通路可通过蛋白和mRNA水平促进Smad7表达，反过来其又可促进ERK通路激活。（3）ERK通路对Smad2／3蛋白和mRNA水平无影响。

英文摘要：

AIM： To investigate whether extracellular signal regulated kinase （ERK） pathway participates the proliferation of vascular smooth muscle ceils （VSMCs） that is regnlated by transforming growth factorβ（TGF- β）/Smad pathway. METHODS： The rat＇s aorta were removed. The primary VSMCs were isolated and cultured in vitro, then the VSMCs were divided into four groups： （ 1 ） control group; （2） TGF - β1 group; （3） ERK blocking agent group; （4） TGF- β1 ＋ ERK blocking agent group. The prollferation of VSMCs was detected by MTT, the expressions of PCNA, Smad2/3, ERK1/2, Smad7 proteins, the content of phosphorylated ERK1/2 and Smad2/3 proteins were determined by Western blotting and the expressions of Smad2/3, Smad7 mRNA were measured by reverse transcription - polymerase chain reaction （RT -PCR）. RESUILTS ： （1） The expression of PCNA proteins and A value in other groups were decreased obviously compared with control group （P 〈 0. 05 ）, and no difference between the TGF- β1 group and .the TGF-β1 ＋ ERK blocking agent group was observed. （2） The content of phosphorylated Smad2/3, ERK1/2 proteins and the expression of Smad7 proteins in TGF - β1 group were increased （ P 〈 0. 05 ）, and decreased in ERK blocking agent group （ P 〈 0. 05 ）, compared with control group. The content of phosphorylated Smad2/3, ERK1/2 proteins and the expression of Smad7 proteins in TGF - β1 ＋ ERK blocking agent group were decreased compared with TGF - β1 group （P 〈0. 05）. No difference in the expression of Smad2/3, ERK1/2 proteins among different groups was found. （3） The expression of Smad7 mRNA in TGF - β1 group was increased compared with control group （P 〈 0. 05 ）, and decreased in ERK blocking agent and TGF -β1 ＋ ERK blocking agent groups （P 〈0. 05）. Compared with TGF -β1 group, the expression of Smad7 mRNA in TGF - β1 ＋ ERK blocking agent group was decreased （P 〈 0. 05 ）. There was no difference in Smad2 and Smad3 mRNA among differe