摘要
目的探讨钙/钙调蛋白依赖的蛋白激酶Ⅱ(CaMKII)在离体心脏缺血再灌注(IR)损伤中的作用和可能机制。方法采用大鼠离体心脏缺血再灌注(IR 45 min/120 min)模型,将40只大鼠随机分为对照组(Control)、KN-93药物对照组(2.5μmol/L KN-93)、IR组和CaMKII特异性抑制剂KN-93干预缺血再灌注组(KN-93+IR),以左室心脏功能、冠脉流出液中乳酸脱氢酶(LDH)活性和心肌肌钙蛋白(cTnI)含量、心肌梗死面积评价心脏损伤程度,Western-blot检测CaMKII磷酸化(p-CaMKII)、CaMKII氧化(ox-CaMKII)和PLN磷酸化(p-PLN)蛋白的表达,试剂盒检测线粒体超氧化物歧化酶(SOD)的活性和丙二醛(MDA)的含量。结果与Control组相比,KN-93组各项指标均无明显变化;IR组心脏功能、线粒体SOD的活性降低(P<0.01),而心肌梗死面积、冠脉流出液中LDH活性和cTnI含量、p-CaMKII、ox-CaMKII和p-PLN的表达、线粒体MDA的含量均明显升高(P<0.01);KN-93干预IR组可明显改善心脏功能(P<0.01),增加线粒体SOD活性,减小心肌梗死面积、LDH活性、cTnI含量、p-CaMKII、ox-CaMKII和p-PLN的表达以及线粒体MDA含量(P<0.01)。结论 CaMKII参与离体心脏缺血再灌注损伤,抑制CaMKII可通过降低线粒体氧化应激进而减轻离体心脏缺血再灌注损伤。
Objective To investigate the role of calcium/calmodulin-dependent protein kinase II(CaMKII) in myocardial ischemia-reperfusion(IR) injury in isolated perfused rat heart and explore the underlying mechanisms.Methods An ischemiareperfusion(IR) model was prepared using isolated rat hearts perfused with Krebs-Henseleit solution were randomly divided into control group,2.5 μmol/L KN-93 group,IR(induced by ischemia for 45 min followed by reperfusion for 120 min) group and KN-93+IR group.The myocardial performance was evaluated by assessing the left ventricular pressure.Lactate dehydrogenase(LDH) activity and cTnI content in the coronary flow and the infarct size were determined to evaluate the myocardial injury.The phosphorylation of CaMKII(p-CaMKII) and PLN(p-PLN) and oxidation of CaMKII(ox-CaMKII) were measured with Western blotting.The activity of mitochondrial superoxide dismutase(SOD) and the content of malondialdehyde(MDA) were determined using ELISA.Results Compared with the control group,KN-93 treatment at2.5 μmol/L produced no significant effects on cardiac function or performance in rat hearts without IR injury.Myocardial IR injury significantly decreased myocardial performance and mitochondrial SOD activity in the perfused hearts(P〈0.01) and caused significantly increased infarct size,LDH activity,cTnI content,expressions of p-CaMKII,ox-CaMKII and p-PLN,and also increased mitochondrial MDA content(P〈0.01).KN-93 treatment at 2.5 μmol/L administered before ischemia and before reperfusion markedly attenuated such changes induced by ischemia and reperfusion(P〈0.01).Conclusion CaMKII participates in myocardial IR injury in isolated rat heart,and inhibiting CaMKII can alleviate myocardial injury by relieving mitochondrial oxidation stress.
作者
孔令恒
陈玉龙
孙娜
魏明
朱娟霞
苏兴利
KONG Lingheng1,CHEN Yulong2,SUN Na1,WEI Ming1,ZHU Juanxia1,SU Xingli1(Institute of Basic Medical Science, School of Basic Medical Sciences1, Institute of Basic and Translational Medicine2, Xi'an Medical College, Xi'an 710021, Chin)
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2018年第2期181-186,共6页
Journal of Southern Medical University
基金
陕西省教育厅重点实验室科研计划项目(16JS098)
陕西省缺血性心血管疾病重点实验室开放基金(2017ZDKF10)
陕西省基础医学优势学科建设经费(陕教位[2014]3号-1001)
陕西省中医管理局中医药基础研究项目(JCMS023)
西安医学院校级重点学科(神经-内分泌生理)
关键词
钙/钙调蛋白依赖的蛋白激酶Ⅱ
心脏缺血再灌注损伤
线粒体
超氧化物歧化酶
丙二醛
calcium/calmodulin-dependent protein kinase II
myocardial ischemia reperfusion injury
mitochondria
superoxide dismutase
malondialdehyde