IGF-1促进山羊瘤胃上皮细胞增殖的机制  

Mechanism of IGF-1 on proliferation of rumen epithelium of goats in vitro

作　　者：卢劲晔[1,2] 卢炜[1] 刘静[1] 陆江[1] 翟晓虎[1,2] 沈赞明[2] 

机构地区：[1]江苏农牧科技职业学院,江苏泰州225300 [2]南京农业大学动物医学院,江苏南京210095

出　　处：《南京农业大学学报》2014年第5期106-110,共5页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(30771568);国家973计划项目(2011CB100801)

摘　　要：通过体外试验研究胰岛素样生长因子1(IGF-1)对山羊瘤胃上皮细胞增殖的影响,胰岛素样生长因子1型受体(IGF-1R)以及受体后信号转导途径在此过程中所起的作用。试验采用IGF-1、IGF-1R抑制剂分别处理体外培养的瘤胃上皮细胞,研究IGF-1对瘤胃上皮细胞增殖、细胞周期蛋白表达及增殖相关信号转导途径中关键蛋白的活化水平;并用添加胞外调节蛋白激酶(ERK)抑制剂、蛋白激酶-B(AKT)抑制剂处理,研究增殖相关信号转导途径在IGF-1诱导瘤胃上皮细胞增殖中的作用。结果表明:IGF-1显著提高体外培养瘤胃上皮细胞3H-TdR掺入率(P<0.05)和细胞周期蛋白cyclin D1表达(P<0.05);且IGF-1处理30 min(P<0.05)和60 min(P<0.05)pERK/ERK比率显著提高,对AKT蛋白活化水平无显著影响(P>0.05);而IGF-1R抑制剂(P<0.05)、ERK抑制剂(P<0.05)处理均能反转IGF-1对瘤胃上皮细胞cyclin D1蛋白的促表达作用。结论:IGF-1与IGF-1R结合后,可以激活下游Ras/Raf/MEK/ERK信号转导途径,提高cyclin D1表达,促进瘤胃上皮细胞增殖。The effect of insulin-like growth factor-1 （IGF-1 ）on rumen epithelial cell proliferation and the role of type 1 IGF receptor （IGF-1R） and its signal transduction pathways in the process was studied. Rumen papillae was taken from the ventral blind sac of healthy dried-grass-fed goats （n = 4）after slaughter and were digested by fractional trypsinization. The cells were seeded onto 24-well plates and 25 mL cell culture flasks and incubated at 37 ℃ with 5% CO2 for 24 h to allow attachment. Thereafter,the cultured rumen epithelial ceils were administrated by IGF-1 for 0, 15,30, 60 rain, and then collected for assay of [3H] thymidine incorporation （3H-TdR） and the phosphorylation of extracellular regulated protein kinases （ERK）and serine-threonine protein kinase B （AKT）. The tureen epithelial cells were also treated by IGF-1 ,IGF-1R inhibitor（ cyclolignan picropodophyllin, PPP）, ERK inhibitor and AKT inhibitor to reveal their effects on eyclin D1 and CDK4 protein expression. Results are as follows： IGF-1 administration （25 μg· L-1 ）markedly enhanced the 3 H-TdR incorporation into the DNA （P〈0.05）. IGF-1 did not markedly increase the phosphorylation of ERK of rumen epithelial cells until 30 rain for treatment（ P〈0.05 ）. The phosphorylation of ERK was approximately 55% more at 60 min than control（0 min for treatment,P〈0.05）. There was no significant increase in AKT in response to IGF-1 administration （ P〉0.05 ） , and in this study, no phosphorylated AKT was detected in any group. In vitro, IGF- 1 administration （ 25 μg· L-1 ） also sig- nificantly increased cyclin D1 protein expression of rumen epithelial cells（P〈0.05）. And this could be inhibited by 1GF-1R inhibitor （ P〈0.05 ）, ERK inhibitor （ P 〈 0. 05 ）, AKT inhibitor （ P 〈 0.05 ）, and ERK inhibitor and AKT inhibitor （ P 〈 0.05 ） respectively. However,expression of CDK4 protein was so steady that there was no significant difference between each group under different treat

关 键 词：IGF-1 IGF-1R 胞外调节蛋白激酶(ERK) CYCLIN D1 细胞增殖 瘤胃上皮 

分 类 号：S852.21[农业科学—基础兽医学]