Role of reactive oxygen species and NAD(P)H oxidase in α1-adrenoceptor signaling in adult rat cardiac myocytes
Role of reactive oxygen species and NAD(P)H oxidase in α1-adrenoceptor signaling in adult rat cardiac myocytes
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DOI：
10.1152/ajpcell.00254.2001
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发表时间：
2002-04-01
影响因子：
5.5
通讯作者：
Sawyer, DB
中科院分区：
文献类型：
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作者：
Xiao, L;Pimentel, DR;Sawyer, DB
我们最近报道，α(1)-肾上腺素能受体(α(1)-AR)刺激通过激活有丝分裂原/细胞外信号调节激酶(MEK)1/2-细胞外信号调节激酶(ERK)1/2通路诱导成年大鼠心室肌细胞(ARVM)肥大，并产生活性氧(ROS)。在这里，我们研究了ARVM中ROS的细胞内来源，以及ROS在α(1)-AR刺激后激活肥大信号的机制。ROS清除剂五氯吡啶锰(MnTMPyP)可完全抑制α(1)-AR刺激的RAS-MEK1/2-ERK1/2的激活。直接加入H_2O_2或超氧化物生成剂孟乃二酮可抑制ERK1/2的激活，而MnTMPyP也可阻止这种激活。我们发现ARVM表达NAD(P)H氧化酶的四个主要成分gp91(Phox)、p22(Phox)、p67(Phox)和p47(Phox)，并且α(1)-AR刺激的ERK1/2的激活可以被四种结构无关的NAD(P)H氧化酶的抑制剂[二苯基碘、氧化苯砷、4-(2-氨基乙基)苯磺酰氟和镉]所阻断。相反，其他潜在的ROS产生系统的抑制剂，包括线粒体电子传输链、一氧化氮合酶、黄嘌呤氧化酶和环氧合酶，对α(1)-AR刺激的ERK1/2激活没有影响。综上所述，我们的结果表明，心室肌细胞表达NAD(P)H氧化酶的组成部分，似乎参与了α(1)-AR刺激的肥大信号转导，通过ROS介导的Ras-MEK1/2-ERK1/2的激活。
We recently reported that alpha(1)-adrenoceptor (alpha(1)-AR) stimulation induces hypertrophy via activation of the mitogen/extracellular signal-regulated kinase (MEK)1/2-extracellular signal-regulated kinase (ERK) 1/2 pathway and generates reactive oxygen species (ROS) in adult rat ventricular myocytes (ARVM). Here we investigate the intracellular source of ROS in ARVM and the mechanism by which ROS activate hypertrophic signaling after alpha(1)-AR stimulation. Pretreatment of ARVM with the ROS scavenger Mn(III) terakis(1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP) completely inhibited the alpha(1)-AR-stimulated activation of Ras-MEK1/2-ERK1/2. Direct addition of H2O2 or the superoxide generator menadione activated ERK1/2, which is also prevented by MnTMPyP pretreatment. We found that ARVM express gp91(phox), p22(phox), p67(phox), and p47(phox), four major components of NAD(P) H oxidase, and that alpha(1)-AR-stimulated ERK1/2 activation was blocked by four structurally unrelated inhibitors of NAD( P) H oxidase [diphenyleneiodonium, phenylarsine oxide, 4-(2-aminoethyl) benzenesulfonyl fluoride, and cadmium]. Conversely, inhibitors for other potential ROS-producing systems, including mitochondrial electron transport chain, nitric oxide synthase, xanthine oxidase, and cyclooxygenase, had no effect on alpha(1)-AR-stimulated ERK1/2 activation. Taken together, our results show that ventricular myocytes express components of an NAD( P) H oxidase that appear to be involved in alpha(1)-AR-stimulated hypertrophic signaling via ROS-mediated activation of Ras-MEK1/2-ERK1/2.