Targeted inhibition of p38 mitogen-activated protein kinase antagonizes cardiac injury and cell death following ischemia-reperfusion in vivo
Targeted inhibition of p38 mitogen-activated protein kinase antagonizes cardiac injury and cell death following ischemia-reperfusion in vivo
复制标题
DOI：
10.1074/jbc.m313717200
复制
发表时间：
2004-04-09
影响因子：
4.8
通讯作者：
Molkentin, JD
中科院分区：
文献类型：
--
作者：
Kaiser, RA;Bueno, OF;Molkentin, JD
丝裂原活化蛋白激酶（MAPK）信号级联的p38分支在培养和成人心脏中被认为是心肌细胞凋亡的调节因子。然而，鉴于已报道的促和抗凋亡调节作用，关于p38信号的功能作用仍存在相当大的分歧。为了解决文献中这一领域的不确定性，我们在培养的新生儿心肌细胞和成人心脏中研究了与p38失活相关的细胞死亡效应。在体外，腺病毒介导的两种不同显性负编码p38载体的基因转移减少了2-脱氧葡萄糖处理诱导的细胞凋亡，而野生型p38α或活化的丝裂原活化蛋白激酶（MKK） 6突变体的过表达均增强了细胞死亡。在体内，通过梗死面积测量、DNA阶梯、末端脱氧核苷酸转移酶介导的dUTP缺口末端标记和心室功能评估来评估，表达显性阴性MKK6突变体或显性阴性p38α突变体的转基因小鼠均能显著保护缺血再灌注损伤。同样，过表达p38失活双特异性磷酸酶MAPK磷酸酶-1 （MKP-1）的转基因小鼠也得到了部分保护，而MKP-1基因靶向小鼠在缺血再灌注损伤后表现出更大的损伤。在机制上，p38信号的抑制促进了转基因小鼠心脏中Bcl-2的显著上调。在初生新生儿心肌细胞培养中，腺病毒介导的p38抑制突变体的基因转移上调了Bcl-2，而激活的p38突变体的表达下调了Bcl-2蛋白水平。总的来说，这些结果表明p38在培养的肌细胞和完整的心脏中都是一种前死亡信号效应因子。
The p38 branch of the mitogen-activated protein kinase ( MAPK) signaling cascade has been implicated as a regulator of cardiomyocyte apoptosis in culture as well as in the adult heart. However, considerable disagreement persists as to the functional effects attributed to p38 signaling, given that both pro- and anti-apoptotic regulatory roles have been reported. To address this area of uncertainty in the literature, we investigated the cell death effects associated with p38 inactivation in both cultured neonatal cardiomyocytes and the adult heart. In vitro, adenoviral-mediated gene transfer of two different dominant-negative-encoding p38 vectors reduced apoptosis induced by 2-deoxyglucose treatment, whereas overexpression of wild-type p38alpha or an activated mitogen-activated protein kinase kinase (MKK) 6 mutant each enhanced cell death. In vivo, transgenic mice expressing a dominant-negative MKK6 mutant or a dominant-negative p38alpha mutant were each significantly protected from ischemia-reperfusion injury, as assessed by infarct area measurements, DNA laddering, terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and functional assessment of ventricular performance. Similarly, transgenic mice overexpressing the p38-inactivating dual specificity phosphatase MAPK phosphatase-1 (MKP-1) were also partially protected, whereas MKP-1 gene-targeted mice showed greater injury after ischemia-reperfusion injury. Mechanistically, inhibition of p38 signaling promoted a dramatic up-regulation of Bcl-2 in the hearts of transgenic mice. In primary neonatal cardiomyocyte cultures, adenoviral-mediated gene transfer of a p38 inhibitory mutant upregulated Bcl-2, whereas expression of an activated p38 mutant down-regulated Bcl-2 protein levels. Collectively, these results indicate that p38 functions as a prodeath signaling effector in both cultured myocytes as well as in the intact heart.