Role of intracellular calcium mobilization and cell-density-dependent signaling in oxidative-stress-induced cytotoxicity in HaCaT keratinocytes
Role of intracellular calcium mobilization and cell-density-dependent signaling in oxidative-stress-induced cytotoxicity in HaCaT keratinocytes
复制标题
DOI：
10.1046/j.1523-1747.2003.12329.x
复制
发表时间：
2003-07-01
影响因子：
6.5
通讯作者：
Virág, L
中科院分区：
文献类型：
--
作者：
Bakondi, E;Gönczi, M;Virág, L
过氧亚硝酸盐是一种一氧化氮衍生的细胞毒性介质，在广泛的炎症条件下产生，从晒伤红斑到接触性超敏反应。我们以前的工作表明，在HaCaT细胞的过氧亚硝酸盐的细胞毒性活性涉及凋亡和坏死的途径与聚（ADP-核糖）聚合酶的激活作为一个分子开关转向默认的凋亡途径走向坏死。尽管如此，角质形成细胞被认为是对包括氧化应激在内的环境noxa具有高度抗性。我们着手研究两个参数，细胞内钙动员和高细胞密度，在保护HaCaT细胞过氧亚硝酸盐/氧化应激诱导的细胞毒性的可能作用。首先，我们表征了过氧亚硝酸盐对HaCaT细胞的钙稳态的影响，并证明了真正的过氧亚硝酸盐和过氧亚硝酸盐生成化合物3-吗啉代-悉尼酮亚胺都引发了细胞内钙水平的升高。此外，我们建立了治疗的细胞与细胞渗透性的钙螯合剂BAPTA-AM提供了显着的细胞保护过氧亚硝酸盐和过氧化氢诱导的细胞毒性。此外，当细胞达到汇合时，它们对过氧亚硝酸盐、过氧化氢和超氧化物的毒性作用具有高度抵抗力。钙螯合和高细胞密度所提供的抗氧化应激性涉及抑制聚（ADP-核糖）聚合酶和半胱天冬酶的活化。我们的数据可能提供了一个解释的表面，高度分化的角质形成细胞的抗氧化应激，并表明，基底增殖角质形成细胞是敏感的体内氧化应激损伤的目标。
Peroxynitrite is a nitric-oxide-derived cytotoxic mediator produced in a broad range of inflammatory conditions, ranging from sunburn erythema to contact hypersensitivity. Our previous work has shown that in HaCaT cells the cytotoxic activity of peroxynitrite involves both apoptotic and necrotic routes with poly(ADP-ribose) polymerase activation serving as a mol-ecular switch diverting the default apoptotic pathway toward necrosis. Nonetheless, keratinocytes are regarded as highly resistant toward environmental noxa including oxidative stress. We set out to investigate the possible role of two parameters, intracellular calcium mobilization and high cell density, in protecting HaCaT cells from peroxynitrite/oxidative-stress-induced cytotoxicity. First we characterized the effect of peroxynitrite on the calcium homeostasis of HaCaT cells and demonstrated that both authentic peroxynitrite and the peroxynitrite generating compound 3-morpholino-sydnonimine triggered an elevation in intracellular calcium levels. Moreover, we established that treatment of cells with the cell-permeable calcium chelator BAPTA-AM provided significant cytoprotection against peroxynitrite- and hydrogen-peroxide-induced cytotoxicity. Furthermore, when cells reached confluence they were highly resistant to the toxic effects of peroxynitrite, hydrogen peroxide, and superoxide. The resistance to oxidative stress provided by calcium chelation and high cell density involved inhibiting the activation of both poly(ADP-ribose) polymerase and caspases. Our data may provide an explanation for the resistance to oxidative stress of superficial, highly differentiated keratinocytes and indicate that basal proliferative keratinocytes are sensitive in vivo targets of oxidative stress injury.