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钙调神经磷酸酶信号通路参与前列腺素F_(2#alpha#)诱导的心肌肥厚

蒋青松, 黄燮南, 杨贵忠, 戴支凯, 周岐新, 石京山, 吴芹

遵义医学院药理教研室.贵州，遵义 563003；重庆医科大学药理教研室.重庆 400016

摘要

利用野百合碱(monocrotaline，MCT) 诱导大鼠右心室肥厚模型和培养乳鼠心肌细胞，研究前列腺素F_(2#alpha#) (prostaglandin F_(2#alpha#)，PGF_(2#alpha#)) 在心肌肥厚中的作用及钙调神经磷酸酶(calcineurin，CaN)信号通路在其中的作用。在雄性Sprague--Dawley 大鼠中，用MCT (60 mg/kg) 单次i.p.诱导右心室肥厚，同时用塞来昔布 (20 mg/kg) 预防/治疗给药2周。用病理检测、电镜观察等方法观察心肌肥厚时组织病理改变；EIA试剂盒检测心肌组织PGF_(2#alpha#)含量；RT--PCR检测心房钠尿肽(atrial natriuretic peptide，ANP)和CaN mRNA的表达；用蛋白免疫印迹法检测CaN及其下游因子NFAT_(3)和GATA_(4)蛋白质的表达。以心肌细胞直径、 蛋白含量和ANP mRNA表达的变化为0.1 #mu#mol/L PGF_(2#alpha#)诱导心肌细胞肥大的指标。以CaN mRNA 表达作为该信号通路的主要指标，并观察CaN抑制剂环孢素A对PGF_(2#alpha#)所致心肌细胞肥大和CaN mRNA表达的影响。结果显示：MCT注射2周(M2W组)，右心室肥厚指数(RVHI)、右心室/体重比及肺重/体重比分别增加了47%、53%和 118%；注射后4周(M4W组)增加了 64%、94%及156%。电镜观察发现右心室组织损伤。同时，右心室组织PGF_(2#alpha#)含量在M2W和M4W组分别增加了44%和51%，与RVHI、ANP和CaN的mRNA表达，及CaN/NFAT_(3)/GATA_(4)的蛋白质表达均呈正相关。环氧酶抑制剂塞来昔布预防和治疗给药均明显改善MCT诱导的组织病理学改变。在离体细胞培养中，PGF_(2#alpha#)(0.1 #mu#mol/L) 明显使心肌细胞增大，蛋白质含量增加，ANP和CaN mRNA表达增强；同时，CaN抑制剂环孢素A明显抑制PGF_(2#alpha#)诱导的心肌细胞肥大和CaN mRNA表达。上述结果提示：心肌组织局部PGF_(2#alpha#)参与了MCT诱导的心肌肥厚过程，CaN信号通路是其细胞内信号转导通路之一。

关键词： 前列腺素F_(2#alpha#); 心肌肥厚; 钙调神经磷酸酶; 野百合碱

Cardiac hypertrophy induced by prostaglandin F_(2#alpha#) may be mediated by calcineurin signal transduction pathway in rats

Jiang Qingsong, Huang Xienan, Yang Guizhong, Dai Zhikai, Zhou Qixin, Shi Jingshan, Wu Qin

Department of Pharmacology, Zunyi Medical College.Zunyi 563003,Guizhou；China

Abstract

In this paper, we studied the relationship between the prostaglandin F_(2#alpha#) (PGF_(2#alpha#))-induced cardiac hypertrophy and calcineurin (CaN) signal transduction pathway in vivo and in vitro. Male Sprague-Dawley rats were given a single i.p. injection with monocrotaline (MCT) (60 mg/kg) and then given orally with celecoxib (20 mg/kg) or vehicle once a day for 14 d before (from d 1 to d 14) or after (from d 15 to d 28) right ventricular hypertrophy (RVH) was formed. Body weight (BW), right ventricular weight (RV), left ventricular with septum weight (LV), as well as lung weight were determined. RVH index (RVHI=RV/LV), RV/BW, and lung weight/BW were calculated and histological changes were observed with transmission electron microscope. PGF_(2#alpha#) level, atrial natriuretic peptide (ANP) and CaN mRNA expressions, expression of CaN and its downstream effectors, NFAT_(3) and GATA_(4) protein were assayed by EIA kit, RT-PCR, and Western blotting, respectively. The cardiomyocyte hypertrophy in primary culture induced by PGF_(2#alpha#) (0.1 #mu#mol/L) was evaluated by measuring the cell diameter, protein content, and ANP mRNA as well as CaN mRNA expressions. It was found that 14 d or 28 d after MCT was given, the RVHI, RV/BW, and lung weight/BW were significantly increased by 47%, 53% and 118%, and by 64%, 94% and 156%, respectively; at the same time PGF_(2#alpha#) levels in RV tissue were increased by 44% and by 51% with increasing RVHI, and elevated expressions of ANP and CaN mRNA, as well as CaN, NFAT_(3) and GATA_(4) proteins in a positive correlation manner. Furthermore, some histological injuries were found in RV tissue. Celecoxib, a cyclooxygenase inhibitor, obviously blunted the elevation of RVHI, RV/BW, and lung weight/BW no matter it was given before or after RVH. In vitro experiments showed that 0.1 #mu#mol/L PGF_(2#alpha#) significantly increased the cardiomyocyte diameter and protein content, and promoted ANP and CaN mRNA expressions, which was blocked by cyclosporin A, a CaN inhibitor. Our results indicate that PGF_(2#alpha#) may be involved in cardiac hypertrophy induced by MCT in rats through CaN signal transduction pathway.

Key words: Prostaglandin F_(2#alpha#);Cardiac hypertrophy;calcineurin;Monocrotaline

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引用本文：

蒋青松, 黄燮南, 杨贵忠, 戴支凯, 周岐新, 石京山, 吴芹 . 钙调神经磷酸酶信号通路参与前列腺素F_(2#alpha#)诱导的心肌肥厚[J]. 生理学报 2005; 57 (6): .

Jiang Qingsong, Huang Xienan, Yang Guizhong, Dai Zhikai, Zhou Qixin, Shi Jingshan, Wu Qin. Cardiac hypertrophy induced by prostaglandin F_(2#alpha#) may be mediated by calcineurin signal transduction pathway in rats . Acta Physiol Sin 2005; 57 (6): (in Chinese with English abstract).