摘要
为了探讨肥大心肌细胞对凋亡刺激的易感性及蛋白激酶Cδ(protein kinase Cδ,PKCδ)在其中的作用,以内皮素-1 (endothelin-1,ET-1)处理原代培养的新生大鼠心肌细胞,诱导心肌细胞肥大；再用血管紧张素Ⅱ(angiotensin II,Ang II)作为细胞凋亡诱导因子,采用鬼笔环肽(phalloidin)荧光染色与细胞面积测量两种方法检测心肌肥大,Hoechst 33258荧光染色检测细胞凋亡。结果显示：(1)1与10 nmol/L ET-1作用48h,心肌细胞肌原纤维排列整齐、染色增浓,随ET-1浓度增加而愈加明显,心肌细胞表面积分别增加42．5%和67．3%,以此作为轻度和中度心肌细胞肥大模型。(2)正常、轻度肥大与中度肥大心肌细胞受1nmol/L AngⅡ处理24h后,凋亡率分别为(15．54±1．32)%、(20．65±1．40)%与(29．33±3．52)%,三组之间有显著差异(P＜0．05)。(3)受AngⅡ刺激后,PKCδ特异性抑制剂rottlerin不影响正常心肌细胞的凋亡率,却有效抑制了轻度和中度肥大心肌细胞的凋亡。肥大心肌细胞凋亡易感性明显高于正常心肌细胞,抑制PKCδ可以抑制肥大心肌细胞凋亡,提示PKCδ参与肥大心肌细胞凋亡过程。
Cardiac hypertrophy is an adaptive process to an increased hemodynamic overload. However, the adaption may lead to the fragility of myocardium facing pathological stimuli. In the present study, experiments were designed to explore the susceptibility of hypertrophic myocardiocytes to apoptotic stimuli and the role of protein kinase Cδ （PKCδ） during the transition from hypertrophy to apoptosis. Endothelin-1 （ET-1）-treated cardiomyocytes were used as model of cardiac hypertrophy. Angiotensin Ⅱ （Ang Ⅱ） was used as an apoptotic stimulus. Cell surface area was measured to determine the extent of hypertrophy. The apoptotic rate in cardiomyocytes was detected by Hoechst 33258. （1） Cell surface area was increased by 42.5% and 67.3% following 1 nmol/L and 10 nmol/L ET-1 treatment, respectively, as compared with serum-free cultured myocytes. So the mildly and moderately hypertrophic myocyte models were set up. （2） Apoptotic rates in serum-free cultured, mildly and moderately hypertrophic myocytes after Ang Ⅱ treatment were （15.54± 1.32）%, （20.65± 1.40）% and （29.33±3.52）%, respectively. It is suggested that hypertrophic myocytes are more susceptive to apoptotic stimulus. （3） Rottlerin, a specific inhibitor of PKCδ depressed apoptotic rates induced by Ang Ⅱ to （15.88±2.25）% in mildly hypertrophic myocytes and to （15.01 ± 1.37）% in moderately hypertrophic myocytes; but rottlerin did not affect apoptotic rate induced by Ang Ⅱ in serum-free cultured myocytes. These results suggest that inhibition of PKCδ can reduce Ang Ⅱ-induced apoptosis of hypertrophic cardiomyocytes and that PKCδ is possibly involved in the apoptotic process of hypertrophic cardiomyocytes.
出处
《生理学报》
CAS
CSCD
北大核心
2006年第3期269-274,共6页
Acta Physiologica Sinica
基金
This work was supported by the Foundation for University Excellent Young Teachers by Ministry of Education
China.
