Slukvin I I, Jerrells T R
Department of Cellular Biology and Anatomy, Louisiana State University Medical Center, Shreveport 71130, USA.
Immunopharmacology. 1995 Nov;31(1):43-57. doi: 10.1016/0162-3109(95)00032-4.
To investigate the intracellular pathways leading to ETOH-induced apoptosis, thymocytes and splenic T and B cells were cultured 16 h with or without ETOH and different stimuli, and apoptotic cell death was determined. At concentrations of 0.4%-2% in culture, ETOH induced apoptosis in all three types of cells, but it had a more profound effect on thymocytes and B cells as compared with its effect on T cells. In thymocytes, ETOH-induced apoptosis was abrogated by chelation of extracellular calcium with EGTA, and inhibition of protein synthesis with CHX, or of PKC with H7 but not of PKA with HA 1004. ETOH potentiated the apoptosis of thymocytes induced with the calcium ionophore A23187 and suboptimal doses of PMA, but it had negligible effect on dAMP- and PGE2-induced apoptosis of thymocytes. In contrast to findings in thymocytes, the ETOH-induced apoptosis of T and B cells was almost completely abrogated by PMA, but not by H7 or CHX. In spleen cells, calcium chelation with EGTA triggered apoptosis. ETOH significantly inhibited EGTA-induced apoptosis of B cells but had little effect on EGTA-induced apoptosis of T cells. IL-4 reduced the ETOH-induced apoptosis of B and T cells, but it was not effective in the prevention of apoptosis of thymocytes. Inhibition of the calcium-dependent neutral protease calpain I did not rescue cells from apoptosis. Moreover, treatment with CI-I potentiated ETOH-induced apoptosis in T cells. These results suggest that both thymocytes and splenic T and B cells have relevant apoptotic pathways that can be induced by ETOH, but the mechanisms of ETOH-induced apoptosis differ in these cells.
为了研究导致乙醇诱导细胞凋亡的细胞内信号通路，将胸腺细胞、脾脏T细胞和B细胞在有或无乙醇及不同刺激物的条件下培养16小时，然后测定凋亡性细胞死亡情况。在培养物中乙醇浓度为0.4%-2%时，乙醇诱导了所有这三种类型细胞的凋亡，但与对T细胞的影响相比，它对胸腺细胞和B细胞的影响更为显著。在胸腺细胞中，用乙二醇双四乙酸（EGTA）螯合细胞外钙、用环己酰亚胺（CHX）抑制蛋白质合成或用H7抑制蛋白激酶C（PKC）可消除乙醇诱导的凋亡，但用HA 1004抑制蛋白激酶A（PKA）则不能。乙醇增强了钙离子载体A23187和次优剂量佛波酯（PMA）诱导的胸腺细胞凋亡，但对二磷酸腺苷（dAMP）和前列腺素E2（PGE2）诱导的胸腺细胞凋亡影响可忽略不计。与胸腺细胞中的发现相反，PMA几乎完全消除了乙醇诱导的T细胞和B细胞凋亡，但H7或CHX则不能。在脾细胞中，用EGTA螯合钙会引发凋亡。乙醇显著抑制EGTA诱导的B细胞凋亡，但对EGTA诱导的T细胞凋亡影响很小。白细胞介素-4（IL-4）减少了乙醇诱导的B细胞和T细胞凋亡，但在预防胸腺细胞凋亡方面无效。抑制钙依赖性中性蛋白酶钙蛋白酶I不能使细胞免于凋亡。此外，用CI-I处理增强了乙醇诱导的T细胞凋亡。这些结果表明，胸腺细胞以及脾脏T细胞和B细胞都有可被乙醇诱导的相关凋亡信号通路，但乙醇诱导凋亡的机制在这些细胞中有所不同。
