BCL-2 and MCL-1 expression in Chinese hamster ovary cells inhibits intracellular acidification and apoptosis induced by staurosporine.
BCL-2 and MCL-1 expression in Chinese hamster ovary cells inhibits intracellular acidification and apoptosis induced by staurosporine.
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DOI：
10.1006/excr.1996.0194
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发表时间：
1996-06
影响因子：
3.7
通讯作者：
J. Reynolds;J. Li;R. Craig;A. Eastman
中科院分区：
文献类型：
--
作者：
J. Reynolds;J. Li;R. Craig;A. Eastman
多种生理和药理刺激诱导细胞凋亡。在许多情况下，这种细胞凋亡被 BCL-2 抑制，表明存在共同的调控途径。细胞凋亡的一个常见特征是将 DNA 消化成寡核小体长度的片段。细胞内酸化和细胞内钙增加在不同程度上与负责 DNA 消化的核酸内切酶的激活有关。为了探索这些潜在信号在内切核酸酶激活中的作用，我们分析了三种中国仓鼠卵巢细胞系：一种是亲本细胞系，一种表达编码 BCL-2 的 cDNA，第三种表达 BCL-2 家族成员 MCL-1。用蛋白激酶抑制剂星形孢菌素诱导细胞凋亡，并通过流式细胞术测量细胞内pH和钙。我们发现，与亲代细胞系相比，MCL-1 和 BCL-2 均抑制 DNA 消化，尽管 BCL-2 在这方面更有效。在 DNA 消化的同时，我们观察到细胞内酸化； MCL-1 和 BCL-2 抑制细胞内酸化的程度与其抑制 DNA 消化的能力相当。相反，星形孢菌素引起所有三种细胞系中细胞内钙的剂量依赖性增加，表明细胞内游离钙水平与细胞凋亡的诱导不相关。这些结果表明 BCL-2 和 MCL-1 可能调节细胞凋亡过程中细胞内 pH 稳态的途径。
Multiple physiological and pharmacological stimuli induce cells to die by apoptosis. In many cases, this apoptosis is inhibited by BCL-2, suggesting the involvement of a common regulatory pathway. One frequent characteristic of apoptosis is the digestion of DNA into oligonucleosome-length fragments. Intracellular acidification and increased intracellular calcium have been variously implicated in activating the endonuclease responsible for this DNA digestion. To explore the involvement of these potential signals in endonuclease activation, we have analyzed three Chinese hamster ovary cell lines: a parental line, one expressing a cDNA encoding BCL-2, and the third expressing the BCL-2 family member MCL-1. Apoptosis was induced with the protein kinase inhibitor staurosporine and intracellular pH and calcium were measured by flow cytometry. We found that both MCL-1 and BCL-2 inhibited DNA digestion compared to the parent cell line, although BCL-2 was more potent in this regard. Concurrent with DNA digestion, we observed intracellular acidification; MCL-1 and BCL-2 inhibited intracellular acidification to an extent commensurate with their ability to inhibit DNA digestion. In contrast, staurosporine caused a dose-dependent increase in intracellular calcium in all three cell lines, demonstrating that intracellular free calcium levels did not correlate with the induction of apoptosis. These results suggest that BCL-2 and MCL-1 may regulate a pathway for intracellular pH homeostasis during apoptotic cell death.