UVB诱导NIH3T3细胞凋亡时的信号转导机制:Ⅱ.神经酰胺所致细胞内Ca^(2+)和pH的变化  

THE ROLE OF CERAMIDE IN THE SIGNAL TRANSDUCTION DURING THE NIH 3T3 CELL APOPTOSIS INDUCED BY UVB IRRADIATION: Ⅱ. VARIATIONS OF INTRACELLULAR Ca^(2+) AND pH DURING THE NIH 3T3 CELL APOPTOSIS INDUCED BY EXOGENOUS CERAMIDE

作　　者：丁振华[1] 刘斐球[1] 黄美贤 郑莉[1] 周美娟[1] 

机构地区：[1]第一军医大学热卫系放射医学教研室,广州510515

出　　处：《生物物理学报》2000年第2期394-400,共7页Acta Biophysica Sinica

基　　金：国家自然科学基金!(39970187);广东省自然科学基金!(960371);军队医药卫生基金;"九五"项目资助

摘　　要：利用粘附式细胞仪 (ACAS -570)结合相应的荧光探针分别测定了外源性神经酰胺诱导NIH3T3细胞凋亡时胞浆游离Ca2 +水平和UVB照射NIH3T3细胞所致细胞内 pH的变化以及神经酰胺的生成对这一变化的影响。结果表明 :1.神经酰胺能够导致NIH3T3细胞胞浆游离Ca2 + 升高 ;胞浆Ca2 + 升高既来源于胞外钙 ,又来源于胞内钙池 ,但外钙内流是引起和维持胞内Ca2 + 处于高水平的必要条件 ;NIH3T3细胞钙池上存在着两种受体 :IP3 受体和Ryanodine受体 ,其中IP3受体较占优势。2.UVB照射导致NIH3T3细胞凋亡时胞浆碱化并持续约2小时左右恢复正常 ,pH的变化参与了细胞凋亡的过程并受到神经酰胺生成的调控。这可能是UVB照射启动了磷脂肌醇通路激活磷脂酶C ,导致神经酰胺的生成、Ca2 +动员和蛋白激酶C的活化 ,从而激活Na +/H +对流引起胞浆碱化。所以 ,胞浆游离Ca2 +的增加和 pH的升高不是两个孤立的事件。The variation of cytosol free Ca2+ was monitored continuously using combing the Adherent Cell Analysis and Sorting (ACAS-570) and the fluorescent probe when the NIH 3T3 cell underwent apoptosis which was induced by exogenous ceramide. Both the variation of intracellular pH caused by UVB irradiation and the effect of the ceramide production were also monitored continuously at the same time. The results show that: 1. Exogenous ceramide can elevate the intracellular free Ca2+ which comes both from extracellular and intracellular Ca2+ store and the extracellular free Ca2+ is the main source. There are two kinds of receptors at the intracellular store: IP3 receptor, which is the prominent, and Ryanodine receptor. 2. The intracellular pH was alkalinized and could maintain for as long as 2 hours when the NIH 3T3 cell underwent apoptosis induced by UVB irradiation, that may means that the variation of intracellular pH may both participate apoptosistic process and being regulated by the ceramide which produced by UVB irradiation. The results suggest that phospholipase C may be activated by UVB irradiation which is followed by ceramide production, cytosol free Ca2+ elevation and activation of protein kinase C, and then activates the Na+/H+ antiport which causes the cytosol alkalinization, so there is a close relationship between cytosol free Ca2+ elevation and the cytosol alkalinization.

关 键 词：神经酰胺 细胞凋亡 Ca^2+ PH 信号转导 UVB 

分 类 号：Q28[生物学—细胞生物学] Q682