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| 钙离子/钙调素依赖性蛋白激酶Ⅱ调控压力负荷心力衰竭小鼠心肌细胞肥大和凋亡的作用及机制 |
| 葛广全1,赵峰2,陈道虎1,石振塑1,陈泽伦1,王天光1,王小啟1,何书武1,魏以桢3* |
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(1. 海南医学院第二附属医院心血管外科, 海口 570311;
2. 华中科技大学同济医学院附属协和医院胸外科, 武汉 430027;
3. 中国医学科学院阜外医院成人心脏外科, 北京 100037
*通信作者) |
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| 摘要: |
| 目的 探讨抑制钙离子/钙调素依赖性蛋白激酶Ⅱ（CaMK Ⅱ）调控压力负荷心力衰竭小鼠心肌细胞肥大和凋亡的作用及机制。方法 取6~8周雄性C57BL/6小鼠24只，随机分为4组：假手术组、假手术+KN-93组、主动脉缩窄术（TAC）组、TAC+KN-93组，每组6只。称各组小鼠体重和心脏质量，计算心脏质量指数（HWI）；通过超声心动图评价小鼠心脏结构和功能；WGA、Masson及TUNEL染色分别检测小鼠心肌细胞横截面积、纤维化程度和凋亡水平；qRT-PCR检测心房钠尿肽（ANP）mRNA表达，蛋白质印迹法检测ANP、脑钠肽（BNP）、β肌球蛋白重链（β-MHC）、活化的Caspase 3、活化的Caspase 9、Bcl-2、B淋巴细胞瘤2相关X蛋白（Bax）、磷酸化CaMK Ⅱ（p-CaMK Ⅱ）和沉默调节蛋白3（Sirt3）的表达。结果 与假手术组相比，TAC组小鼠HWI、左心室舒张末期直径（LVEDD）、左心室收缩末期直径（LVESD）均增加（P均<0.05），左心室射血分数（LVEF）和左心室短轴缩短率（LVFS）均降低（P均<0.05）；心肌细胞横截面积增大（P<0.05），心肌组织ANP mRNA和蛋白及BNP、β-MHC蛋白表达均增加（P均<0.05），心肌纤维化和心肌细胞凋亡均增加（P均<0.05），心肌组织凋亡蛋白活化的Caspase 3、活化的Caspase 9和Bax相对表达量均增加（P均<0.05），抗凋亡蛋白Bcl-2相对表达量降低（P<0.05），p-CaMK Ⅱ/CaMK Ⅱ比值下降（P<0.05），Sirt3相对表达量增加（P<0.05）。而给予CaMK Ⅱ抑制剂KN-93后，TAC+KN-93组小鼠上述指标均被逆转，与TAC组相比差异均有统计学意义（P均<0.05）。结论 抑制CaMK Ⅱ能够减轻压力负荷心力衰竭小鼠的心功能不全，抑制心肌细胞肥大及凋亡，且其作用机制与Sirt3有关。 |
| 关键词: 心力衰竭 主动脉缩窄术 压力负荷 心肌肥厚 钙-钙调素依赖性蛋白激酶2型 沉默调节蛋白3 |
| DOI：10.16781/j.0258-879x.2020.12.1314 |
| 投稿时间：2019-10-31修订日期：2020-03-31 |
| 基金项目:海南省卫生计生行业科研项目（1521320273A2001）. |
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| Ca2+/calmodulin-dependent protein kinase Ⅱ in regulating cardiomyocyte hypertrophy and apoptosis in pressure overload-induced heart failure mice: the role and mechanisms |
| GE Guang-quan1,ZHAO Feng2,CHEN Dao-hu1,SHI Zhen-su1,CHEN Ze-lun1,WANG Tian-guang1,WANG Xiao-qi1,HE Shu-wu1,WEI Yi-zhen3* |
(1. Department of Cardiovascular Surgery, Second Affiliated Hospital of Hainan Medical College, Haikou 570311, Hainan, China;
2. Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430027, Hubei, China;
3. Department of Adult Cardiac Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing 100037, China
*Corresponding author) |
| Abstract: |
| Objective To elucidate the role and mechanisms of inhibiting Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) in cardiac hypertrophy and apoptosis in pressure overload-induced heart failure mice. Methods Twenty-four male C57BL/6 mice aged 6-8 weeks were evenly randomized into four groups:sham operation group, sham operation+ KN-93 group, transverse aortic constriction (TAC) group, and TAC+KN-93 group. The body and heart weights of mice in each group were recorded, and the heart weight index (HWI) was calculated; the geometry and function of mouse heart were evaluated by echocardiography; the cross-sectional area, fibrosis degree and apoptosis level of mouse cardiomyocytes were detected by triticum vulgaris lectin (WGA), Masson's trichrome and TUNEL staining, respectively. The mRNA expression of atrial natriuretic peptide (ANP) was determined by qRT-PCR; Western blotting was used to detect the protein expression of ANP, brain natriuretic peptide (BNP), β-myosin heavy chain (β-MHC), cleaved Caspase 3, cleaved Caspase 9, B-cell lymphoma-2 (Bcl-2), B-cell lymphoma-2-related X protein (Bax), phosphorylated-Ca2+/calmodulin-dependent protein kinase Ⅱ (p-CaMKⅡ) and sirtuin3 (Sirt3). Results The HWI, left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) were higher (all P<0.05), while the left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were lower in TAC group compared with those in the sham group (both P<0.05). The cardiomyocyte cross-sectional area, the ANP mRNA level and the protein expressions of ANP, BNP, and β-MHC, and the myocardial fibrosis and cardiac apoptosis were significantly increased in TAC group compared with the sham group (all P<0.05). TAC group also had significantly increased protein expression of apoptosis-related proteins (cleaved Caspase 3, cleaved Caspase 9 and Bax) and decreased anti-apoptosis protein Bcl-2 compared with the sham group (all P<0.05); moreover, the ratio of p-CaMKⅡ/CaMKⅡ was decreased and the expression of Sirt3 was significantly increased in TAC group (both P<0.05). However, the above indexes were significantly reversed in TAC+KN-93 group compared with those in TAC group after the administration of KN-93, a CaMKⅡ inhibitor (all P<0.05). Conclusion Inhibition of CaMKⅡ can alleviate cardiac dysfunction and inhibit cardiac hypertrophy and apoptosis in pressure overload-induced heart failure mice by regulating Sirt3. |
| Key words: heart failure transverse aortic constriction pressure overload cardiac hypertrophy calcium-calmodulindependent protein kinase type 2 sirtuin 3 |
