bFGF激活tyrosine kinase/PI3K/PLCγ增加血管内皮细胞[Mg~(2+)]_i的研究

目的探讨碱性成纤维细胞生长因子(basic fibroblastgrowth factor,bFGF)对人脐带静脉内皮细胞(human umbilicalvein endothelial cells,HUVECs)内游离镁离子浓度(Mg2+]i)的调节机制研究。方法我们采用荧光指示剂mag-fura-2,运用PTi阳离子测定系统动态测HUVECs的Mg2+]i。结果经酪氨酸激酶阻断剂(tyrphostin A23和genistein)、3-磷脂酰肌醇激酶阻断剂(wortmannin和LY294002)、磷脂酶Cγ阻断剂(U73122)预处理,能阻断bF-GF诱导的Mg2+]i增加。但经磷脂酶Cγ阻断剂无活性的类似物(U73343)和丝裂原活化蛋白激酶阻断剂(SB202190和PD98059)预处理,不能阻断bFGF诱导的Mg2+]i增加。结论bFGF通过酪氨酸激酶/3-磷脂酰肌醇激酶/磷脂酶Cγ信号传递途径使细胞内的Mg2+库释放Mg2+,从而增加HUVECs的Mg2+]i。

bFGF increases intracellular free Mg2+by tyrosine kinase/PI3K/PLCγ in HUVECs

Aim To investigate mechanism of basic fibroblast growth factor(bFGF)on intracellular free magnesium(Mg2+]i)in human umbilical vein endothelial cells(HUVECs).Methods Mg2+]i in HUVECs loaded with fluorescent magnesium indicator mag-fura-2 was quantitatively detected with intracellular cation measurement system.Results bFGF significantly increased Mg2+]i in the extracellular Mg2+ and this effect could be blocked by pretreatment with tyrosine kinase inhibitors(tyrphostin A23 and genistein),phosphatidylinositol 3-kinase(PI3-Kinase)inhibitors(wortmannin and LY294002)and phospholipase Cγ(PLCγ)inhibitor(U73122).In contrast,phospholipase Cγ(PLCγ)inhibitor analog(U73343),mitogen-activated protein kinase inhibitors(SB202190 and PD98059)had no effect on the bFGF-induced Mg2+]i increase.Conclusion These results suggest that the increase of Mg2+]i by bFGF originates from intracellular Mg2+ pool through tyrosine kinase/PI3-Kinase/PLCγ-dependent signaling pathways.