膜雌激素受体介导的NO途径对EPCs增殖和凋亡的影响

 【目的】 观察一氧化氮(NO)信号途径在膜雌激素受体介导的内皮祖细胞(EPCs)增殖和凋亡中的作用&;#65377; 【方法】 在培养的EPCs上,分别使用E2-BSA&;#65380;或加雌激素受体阻断剂ICI 182,780&;#65380;PI3K抑制剂LY294002和NOS抑制剂l-NAME,利用噻唑蓝(MTT)法检测细胞增殖活性(10组,n = 9),利用化学比色法测定NO的含量(6组,n = 6),Hoechst 33258染色观察EPCs凋亡(8组,n = 5)以及免疫印迹法检测EPCs磷酸化eNOS蛋白表达的情况(4组,n = 4)&;#65377;【结果】 与对照组相比,E2-BSA 可以促进EPCs的增殖,ICI 182,780可以抑制其增殖作用,表明膜雌激素受体介导的信号通路参与雌激素对EPCs的增殖作用;NO合成和细胞凋亡结果显示,E2-BSA可以促进一氧化氮的合成和抑制血清撤退诱导的凋亡,PI3K抑制剂LY294002&;#65380;NOS 抑制剂l-NAME以及和ICI 182,780可以抑制上述作用;免疫印迹结果显示,E2-BSA可以促使eNOS的磷酸化,而LY294002可抑制上述作用&;#65377;【结论】 膜雌激素受体可通过PI3K/Akt/eNOS信号途径抑制EPCs的凋亡从而促进其增殖&;#65377;

Role of NO Pathway in Membrane Estrogen Receptor Mediated Proliferation and Apoptosis of Endothelial Progenitor Cells

Objective] The aim of the present study was to investigate the role of membrane estrogen receptor (mER) mediated pathway in the proliferation and apoptosis of endothelial progenitor cells (EPCs). Methods] Bone marrow (BM)-derived EPCs were cultured. The cells were divided into different groups, plus or not plus estrogen receptor blocker (ICI 182,780), PI3K inhibitors (LY294002), and NOS inhibitor (L-NAME) to show the effect of E_2-BSA on EPCs. The proliferation of EPCs was determined by MTT and nitric oxide (NO) release was measured by chromatometry. Apoptotic cell death was determined using the Hochest 33258 staining. The expression of phosphorylated eNOS (p-eNOS) were detected by Western blot. Results] E_2-BSA could increase EPCs proliferation, and this effect was inhibited by estrogen receptor blocker ICI 182,780, thus indicated that mER-initiated membrane signaling pathways were involved in the action of estrogen on EPCs. E_2-BSA increased nitric oxide production and inhibited apoptosis induced by serum withdrawal, and this effect also inhibited by PI3K inhibitor (LY294002), NOS inhibitor (L-NAME)and estrogen receptor blocker(ICI 182,780), thus indicated that PI3K/Akt/NO pathway was involved the effect of estrogen on EPCs apoptosis. Moreover, E_2-BSA treatment increased phosphorylation of eNOS (p-eNOS). PI3K inhibitors (LY294002) also blocked these effects. Conclusions] The results of present study suggested that mER mediated EPCs proliferation and apoptosis were related to the PI3K/Akt/eNOS pathway.