摘要
目的探讨蛋白激酶B及其磷酸化在棕榈酸诱导的胰岛素瘤细胞MIN6凋亡中的作用。方法胰岛素瘤细胞MIN6分别在含有不同棕榈酸浓度(0～0.5 mmol/L)的DMEM高糖培养基中孵育,培养基中加或不加PI3K/PKB的阻断剂LY294002;TUNEL法观察凋亡并计数凋亡率;透射电镜观察MIN6细胞超微结构;Western blot检测蛋白激酶B(PKB)及其磷酸化蛋白p-PKB(Ser473)的表达;RT-PCR法检测BAX、BCL-2mRNA的表达。结果MIN6细胞凋亡随着培养基中棕榈酸浓度的增加而增加,LY294002可增强其凋亡程度;棕榈酸抑制MIN6细胞的PKB在473位丝氨酸位点的磷酸化,抑制BCL-2mRNA的表达并促进BAXmRNA的表达。结论棕榈酸可能通过抑制PKB磷酸化的激活而诱导糖尿病时胰岛β细胞的凋亡。
Objective To investigate the effect of protein kinase B and its phosphorylation on the apoptosis of MIN6 induced by palmitate.Methods Incubated with different level of palmitate concentration（0～0.5 mmol/L）,MIN6 cells were cultured in high glucose DMEM with or without LY294002;the apoptosis of MIN6 cells was detected and quantified with TUNEL technology.Then we inspected the cell ultrastructure through electron microscopy and determined the expression of protein kinase B and its phosphorylation p-PKB（Ser473） by Western blot,followed by an RT-PCR detection of BAX and BCL-2 expression.Results Apoptosis of MIN6 cells was induced by palmitate in a concentration-dependent correlation and enhanced by LY294002.Palmitate also inhibited phosphorylation of protein kinase B on Ser473.Finally,we detected a downregulation of BCL-2 mRNA expression and upregulation of BAX mRNA expression under palmitate-incubated state.Conclusion Palmitate may induce apoptosis of pancreatic β-cells through inhibiting activation of PKB phosphorylation in diabetes.
出处
《基础医学与临床》
CSCD
北大核心
2010年第4期401-405,共5页
Basic and Clinical Medicine
