胞浆Ca~(2+)和某些激酶对NADPH氧化酶激活和肌动蛋白聚合的作用

 为澄清中性粒细胞胞浆 Ca2 +和某些 O-·2 产生相关激酶对 NADPH氧化酶激活和肌动蛋白聚合的作用 ,利用分化为中性粒细胞样的 HL- 60细胞研究了胞浆 Ca2 +螯合剂 BAPTA- AM和激酶抑制剂对这些激酶激活、NADPH氧化酶激活和肌动蛋白聚合的影响 .使用 1 0 μmol/L的 Ca2 +螯合剂 BAPTA- AM去除胞浆 Ca2 +后 ,趋化肽 f MLP诱导的 O-·2 产生明显减少 ,但不影响 f MLP诱导的肌动蛋白聚合 ;8μmol/L的 PKC激酶抑制物 GF1 0 92 0 3x几乎完全抑制 O-·2 产生 ;50 μmol/L的p38激酶抑制物 SB2 0 3580、50 μmol/L的 ERK激酶抑制物 PD0 980 59和 0 .1 μmol/L的 PI3激酶抑制物渥曼青霉素 (Wortmannin)使 f MLP诱导的 O-·2 产生大约减少一半 ;其中 Wortmannin还抑制 f MLP诱导的肌动蛋白聚合 ;f MLP刺激细胞后 ,PI3- K、p38和 ERK激酶迅速激活 ,但这些激酶的激活对 Ca2 +是非必需的 .这些结果说明 Ca2 +依赖途径 (PKC)和 Ca2 +非依赖途径 (PI3- K、p38和ERK)对 NADPH氧化酶激活都起着重要作用 ,而 Ca2 +非依赖途径中的 PI3- K激酶还参与中性粒细胞样 HL- 60细胞的肌动蛋白聚合 .

Effects of [Ca~(2+) ]_i and Some Kinases on the Activation of NADPH Oxidase and Actin Polymerization

To clear away the effects of intracellular Ca 2+ (Ca 2+ ] i)and kinases relating to superoxide generation on the activation of NADPH oxidase and actin polymerization in neutrophils,the influence of Ca 2+ ] i chelator (BAPTA AM) and kinase inhibitors on the activation of NADPH oxidase,the actin polymerization and the activation of kinases relating to these functions were studied in differentiated HL\|60.10 μmol/L BAPTA AM significantly attenuated the fMLP\|induced O -· 2 generation,but not the fMLP\|induced polymerization of actin.8 μmol/L GF109293x(PKC inhibitor)almost completely inhibited O -· 2 generation.50 μmol/L SB203580(p38 inhibitor),50 μmol/L PD98059(ERK inhibitor)and 0.1 μmol/L wortmannin(PI 3\|kinase inhibitor)attenuated about half of O -· 2 generation.Wortmannin also inhibited the fMLP\|induced polymerization of actin,although the other inhibitors did not.The activation of PI 3 K,p38 and ERK by fMLP rapidly occurred and the activation of these kinases was not essential to Ca 2+ ] i.These results suggest that both Ca 2+ dependent pathway(PKC)and Ca 2+ independent pathway(PI 3 K,p38 and ERK)are important in the activation of NADPH oxidase,and Ca 2+ independent pathway,mainly PI 3 K,is associated with the polymerization of actin in differentiated HL 60.