Modulation of the alveolar macrophage superoxide production by protein phosphorylation
Modulation of the alveolar macrophage superoxide production by protein phosphorylation
复制标题
DOI：
10.2307/3433984
复制
发表时间：
1998-10-01
影响因子：
10.4
通讯作者：
Torres, M
中科院分区：
文献类型：
--
作者：
Forman, HJ;Zhou, HF;Torres, M
5-二磷酸腺苷（ADP）刺激肺泡巨噬细胞（AM），可引起超氧阴离子自由基（O-2（.-）;超氧化物）和H2 O2在称为呼吸爆发的代谢事件中，呼吸爆发的启动似乎取决于蛋白激酶活性的激活，而蛋白磷酸酶可能参与爆发的终止。通过双吲哚马来酰亚胺I（GF 109203 X）（一种相对特异的抑制剂）的抑制作用，提示蛋白激酶C的参与。钙-钙调蛋白蛋白激酶II抑制剂KN-62也部分抑制ADP和佛波醇酯刺激的呼吸爆发。用蛋白磷酸酶1和2a（PP 1; PP 2a）的两种抑制剂calyculin A（CA）（25-75 nM）或冈田酸（OA）（1-5 μ M）检测蛋白磷酸酶在终止ADP刺激的AM呼吸爆发中的作用。在存在这些抑制剂的情况下，观察到呼吸爆发的剂量依赖性延长。CA和OA也显着提高了ADP刺激的超氧化物产生的速率，这与PP 1/PP 2a参与调节激活速率和终止时间一致。用钙依赖性蛋白磷酸酶2b（PP 2b）的抑制剂环孢菌素A（CsA）（1-50 μ M）处理AM，刺激超氧化物产生本身，并显着延长ADP刺激超氧化物产生的持续时间。然而，CsA并没有增加ADP刺激的超氧化物产生速率。因此，PP 1/PP 2a似乎是主要的磷酸酶，用于控制呼吸爆发的强度，在受体引起的超氧化物产生在AM，而PP 1/PP 2a和PP 2b在关闭呼吸爆发中发挥作用。
Stimulation of alveolar macrophages (AM) with adenosine-5-diphosphate (ADP) results in transient production of superoxide anion radical (O-2(.-); superoxide) and H2O2 in a metabolic event known as the respiratory burst, initiation of the respiratory burst appears to depend on activation of protein kinase activity, whereas protein phosphatases might involved in termination of the burst. The involvement of protein kinase C was suggested by inhibition by bisindolylmaleimide I (GF 109203X), a relatively specific inhibitor. KN-62, an inhibitor of calcium-calmodulin protein kinase II, also partly inhibited the respiratory burst stimulated by ADP and phorbol esters. The role of protein phosphatases in termination of the ADP-stimuiated respiratory burst of AM was examined with calyculin A (CA) (25-75 nM) or okadaic acid (OA) (1-5 mu M), two inhibitors of protein phosphatase 1 and 2a (PP1;PP2a). A dose-dependent prolongation of the respiratory burst was observed in the presence of these inhibitors. CA and OA also markedly enhanced the rate of superoxide production stimulated by ADP, consistent with involvement of PP1/PP2a in regulating both the rate of activation and timing of termination. Treatment of AM with cyclosporin A (CsA) (1-50 mu M), an inhibitor of the calcium-dependent protein phosphatase 2b (PP2b), stimulated superoxide production by itself and significantly prolonged the duration of ADP-stimulated superoxide production. CsA, however, did not increase the ADP-stimulated rate of superoxide production. Thus, PP1/PP2a appear to be the primary phosphatases for controlling the intensity of the respiratory burst during receptor-elicited superoxide production in AM, whereas PP1/PP2a and PP2b play a role in turning off the respiratory burst.