Suppression of PMN apoptosis by hypoxia is dependent on Mcl-1 and MAPK activity
Suppression of PMN apoptosis by hypoxia is dependent on Mcl-1 and MAPK activity
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DOI：
10.1067/msy.2000.107609
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发表时间：
2000-08-01
期刊：
影响因子：
3.8
通讯作者：
Simms, HH
中科院分区：
文献类型：
--
作者：
Leuenroth, SJ;Grutkoski, PS;Simms, HH
背景资料。已有研究表明，低氧可延缓中性粒细胞(PMN)的凋亡。随着反义寡核苷酸的使用，我们先前已经证明Mcl-1是这一效应所必需的。我们希望进一步研究Mcl-1的表达，并研究缺氧所介导的细胞凋亡延迟所需的信号通路。用PD98059丝裂原活化蛋白激酶(MEK)、SB202190(p38氮激活蛋白激酶[MAPK])和LY294002(磷脂酰肌醇-3-激酶：[PI3K])抑制剂孵育PMN 12h。用抑制剂处理的中性粒细胞通过形态特征或裂解进行Western印迹分析来评估细胞的凋亡。Western印迹分析、免疫荧光染色和定量分析表明，在培养12小时后，Mcl-1的表达上调是对缺氧的反应。当MEK或p38MAPK的抑制剂与中性粒细胞在低氧条件下孵育时，凋亡增加到与NO类似的水平。我们进一步想要确定是否通过p38il MAPK或MEK信号导致Mcl-1表达增加。Western印迹分析证实，p38MAPK的抑制导致Mcl-1的表达显著降低。我们发现了一种新的机制，即缺氧可以通过激活p38MAPK信号通路来改变创伤部位PMN的凋亡，从而诱导抗凋亡蛋白Mcl-1。
Background. Hypoxia has been shown to delay the onset of neutrophil (polymorphonuclear leukocytes [PMNs]) apoptosis. With the use of antisense oligonucleotides, we have previously demonstrated that Mcl-1 is necessary for this effect. We wanted to further characterize the expression of Mcl-1 and examine signaling pathways required for the delay in apoptosis that is mediated by hypoxia.Methods. For kinase signaling inhibition, PMNs were incubated for 12 hours with the following inhibitors: PD98059 Mitogen Activated Protein Kinase Kinase (MEK), SB202190 (p38 nitrogen-activated protein kinase [MAPK]), and LY294002 (phosphatidyl inositol-3-kinase: [PI3K]). PMNs that were treated with inhibitors were assessed for apoptosis by morphological features or were lysed for Western blot analysis.Results. Western blot analyses, immunofluorescent staining, and quantification showed an upregulation of Mcl-1 expression after 12 hours of incubation in response to hypoxia. When inhibitors of either MEK or p38 MAPK were incubated with PMNs during hypoxia , apoptosis increased to similar levels,as no I moxia. We further wanted to determine whether signaling through p38 il MAPK or MEK led to increased Mcl-1 expression. Western blot analysis confirmed that the inhibition of p38 MAPK led to a significant decrease in Mcl-1 expression.Conclusions. We have documented a novel mechanism by which hypoxia can modify PMN apoptosis I the wound site by the activation of p38 MAPK signaling thereby inducing the anti-apoptotic protein Mcl-1.