Wang J H, Redmond H P, Watson R W, Condron C, Bouchier-Hayes D
The Royal College of Surgeons in Ireland, Department of Surgery, Beaumont Hospital, Dublin.
Shock. 1999 May;11(5):311-8. doi: 10.1097/00024382-199905000-00002.
Although it is well recognized that interferon-gamma (IFN-gamma) is involved in the development of systemic inflammatory response syndrome, a condition characterized by loss of endothelial barrier function, whether or not IFN-gamma has any direct effect on endothelial cell (EC) death is unclear. Furthermore, which signal transduction pathway involved in IFN-gamma-induced EC apoptosis remains to be elucidated. To answer these questions, we investigated the effect of IFN-gamma on EC death (apoptosis versus necrosis) and the underlying signal transduction pathway responsible for IFN-gamma-induced EC apoptosis. IFN-gamma resulted in a dose-dependent increase in EC apoptosis after 24 h incubation (p < .05). However, IFN-gamma did not induce EC necrosis. Tumor necrosis factor-alpha (TNF-alpha), but not lipopolysaccharide (LPS), had a augmentative effect on IFN-gamma-induced EC apoptosis (p < .05), while both of them alone failed to induce EC apoptosis. These results indicate that exposure of EC to IFN-gamma can cause apoptosis rather than necrosis. Both calcium ionophore, A23187, and the protein kinase C (PKC) activator phorbol-myristate-acetate (PMA) had a synergistic effect on IFN-gamma-induced EC apoptosis (p < .05). However, neither the calcium chelator 1,2-bis 2-aminophenoxy ethane-N,N,N',N'-tetraacetic acid (BAPTA), nor the PKC inhibitor 1 -5-isoquinolinysulfonyl 2-methyl piperazine (H-7) attenuated IFN-gamma-induced EC apoptosis. Three specific tyrosine protein kinase (TPK) inhibitors, herbimycin A, tyrphostin, and genistein, significantly inhibited IFN-gamma-induced EC apoptosis in a dose-dependent fashion (p < .05). Furthermore, the activation of TPK in EC by IFN-gamma was completely abrogated by these TPK inhibitors. These findings suggest that the signal transduction pathway required for induction of EC apoptosis by IFN-gamma is TPK dependent and is independent of calcium and PKC.
虽然人们已经充分认识到γ干扰素（IFN-γ）参与全身性炎症反应综合征的发生发展，该综合征的特征是内皮屏障功能丧失，但IFN-γ是否对内皮细胞（EC）死亡有直接影响尚不清楚。此外，IFN-γ诱导EC凋亡所涉及的信号转导途径仍有待阐明。为了回答这些问题，我们研究了IFN-γ对EC死亡（凋亡与坏死）的影响以及负责IFN-γ诱导EC凋亡的潜在信号转导途径。孵育24小时后，IFN-γ导致EC凋亡呈剂量依赖性增加（p<.05）。然而，IFN-γ并未诱导EC坏死。肿瘤坏死因子-α（TNF-α）而非脂多糖（LPS）对IFN-γ诱导的EC凋亡有增强作用（p<.05），而它们单独作用时均未能诱导EC凋亡。这些结果表明，EC暴露于IFN-γ可导致凋亡而非坏死。钙离子载体A23187和蛋白激酶C（PKC）激活剂佛波醇肉豆蔻酸酯乙酸酯（PMA）对IFN-γ诱导的EC凋亡均有协同作用（p<.05）。然而，钙离子螯合剂1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸（BAPTA）和PKC抑制剂1-（5-异喹啉磺酰基）-2-甲基哌嗪（H-7）均未减弱IFN-γ诱导的EC凋亡。三种特异性酪氨酸蛋白激酶（TPK）抑制剂，即除莠霉素A、 tyrphostin和染料木黄酮，以剂量依赖性方式显著抑制IFN-γ诱导的EC凋亡（p<.05）。此外，这些TPK抑制剂完全消除了IFN-γ对EC中TPK的激活作用。这些发现表明，IFN-γ诱导EC凋亡所需的信号转导途径是TPK依赖性的，且独立于钙离子和PKC。
