美托洛尔抑制NE诱导的大鼠心肌细胞凋亡及缝隙连接蛋白43的磷酸化  

Metoprolol inhibits norepinephrine-induced rat cardiomyocyte apoptosis and connexin 43 phosphorylation

作　　者：梁庆[1,2] 李自成[1] 邝素华[3] 黄伟青[2] 黄敏坚[2] 林俊敏[2] 梁子敬[2] 

机构地区：[1]暨南大学第一临床医学院心血管内科,广东广州510630 [2]广州医科大学附属第一医院急诊科,广东广州510120 [3]广州医科大学附属第一医院心脏外科,广东广州510120

出　　处：《中国病理生理杂志》2013年第11期2024-2029,共6页Chinese Journal of Pathophysiology

基　　金：广东省医学科研基金资助(No.A2013251);广州市科技计划(No.2010Y1-C941);广州市医药卫生科技项目(No.20131A011142)

摘　　要：目的:研究美托洛尔(Meto)对去甲肾上腺素(NE)刺激下乳鼠心肌细胞凋亡及缝隙连接蛋白43(Cx43)磷酸化水平的影响。方法:新生SD乳鼠心肌细胞分为5组:(1)对照组(Con组,n=6);(2)NE组(n=6):在细胞中加入0.1μmol/L NE孵育24 h;(3)NE+Meto组(n=6):细胞中同时加入0.1μmol/L NE和0.1μmol/L Meto孵育24 h;(4)NE+Meto+PD98059组(n=6):细胞中提前30 min加入ERK磷酸化抑制剂10μmol/L PD98059,后同时加入0.1μmol/L NE和0.1μmol/L Meto孵育24 h;(5)NE+PD98059组(n=6):细胞中提前30min加入10μmol/L PD98059,后加入0.1μmol/L NE孵育24 h。24 h后计算各组心肌细胞搏动频率,MTT法检测细胞活性,RT-PCR检测各组心肌细胞Cx43 mRNA表达,采用Western bloting法检测各组心肌细胞p-Cx43、pERK1/2和活化caspase-3蛋白表达。结果:(1)NE单独处理可显著增高心肌细胞搏动频率和降低心肌细胞活性,Meto阻断则可显著降低心肌细胞搏动频率和显著提高细胞活性;而PD98059单独处理则对心肌细胞搏动频率无明显影响,但PD98059处理后可在一定程度上抑制Meto提高细胞活性的作用。(2)与Con组比较,NE单独处理可显著上调心肌细胞Cx43 mRNA表达(P<0.01);而与NE组比较,Meto(P<0.01)或PD98059(P<0.01)的单独干预均可显著抑制Cx43 mRNA的表达,且Meto和PD98059两者共处理心肌细胞可进一步抑制NE上调Cx43 mRNA表达的作用(P<0.01)。(3)与NE组比较,Meto可显著抑制NE诱导的心肌细胞p-Cx43、p-ERK1/2和活化caspase-3表达增加(P<0.01),PD98059和Meto两者共处理后可进一步增强Meto对p-Cx43、p-ERK1/2和活化caspase-3表达的抑制(P<0.01);而PD98059单独处理对NE诱导的心肌细胞p-Cx43和活化caspase-3表达增加则无显著影响(P>0.05)。结论:美托洛尔对NE诱导的心肌细胞凋亡的抑制作用与其独特的Cx43磷酸化抑制作用有关,该作用可能部分经由ERK1/2通路介导。AIM： To study the effects of metoprolol （Meto） on the apoptosis of neonatal rat cardiomyocytes and the phosphorylation of connexin 43 （Cx43） induced by norepinephfine （NE）. METHODS ： Neonatal SD rat cardiomyocytes were divided into the following five groups （n = 6 in each group） ： （1） control （Con） group： no treatment; （2） NE group： treatment with NE at 0.1 txmol/L for 24 h ; （3） NE ＋ Meto group ： simultaneous treatment with NE and Meto both at 0. 1 μmol/L for 24 h; （4） NE ＋ Meto ＋ PI）98059 group： pretreatment with extracellular signal-regulated kinase（ERK） phosphorylation inhibitor PD98059 at 10 μmol/L for 30 min and then treatment with NE and Meto both at 0. 1 μmol/L for 24 h; （5） NE ＋ PD98059 group： pretreatment with PD98059 at 10 izmol/L for 30 min and then treatment with NE at 0. 1 μmol/L for 24 h. The beating rates of cardiomyocytes in various groups were calculated, and the viability of car- diomyocytes was assayed by MrIT method. The Cx43 mRNA expression was detected by RT-PCR, and the protein expres- sion of phosphorylated Cx43 （ p-Cx43 ）, phosphorylated ERK1/2 （p-ERK1/2） and cleaved caspase-3 was detected by Western blotting. RESULTS ： （ 1 ） Separate NE treatment could significantly increased the beating rate of cardiomyocytes and reduced cell viability, while Meto showed the opposite effects. PD98059 treatment had no significant effect on cardiomyocyte beating rate, but suppressed Meto to improve cell viability to some extent. （2） Compared with Con group, sepa- rate NE treatment significantly increased the Cx43 mRNA expression （ P 〈 0. 01 ）. Compared with NE group, Meto or PD98059 intervention could significantly inhibited Cx43 mRNA expression （ both P 〈 0. 01 ）, and simultaneous treatment with Meto and PD98059 could further suppress Cx43 mRNA expression up-regulated by NE （ P 〈 0. 01 ）. （ 3 ） Compared with NE group, Meto significantly inhibited the increased p-Cx43, p-ERK1/2 and cleaved ca

关 键 词：乳鼠心肌细胞 美托洛尔 去甲肾上腺素 缝隙连接蛋白43 

分 类 号：R541.6[医药卫生—心血管疾病]