[关键词]
[摘要]
目的 探讨泻肺利水中药心康方 (葶苈子、杏仁、茯苓、黄芪、陈皮、三棱) 调控受磷蛋白 (PLN) 磷酸化治疗心力衰竭的作用机制。方法 将 48 只 C57BL/6J 小鼠随机分为假手术组、模型组、诺欣妥组 (25 mg•kg-1)及心康方低、中、高剂量组 (0.455、0.91、1.82 g•kg-1) ,每组 8 只。采用结扎冠状动脉左前降支的方法复制心力衰竭小鼠模型。模型复制成功后,按照上述剂量灌胃给药,每天 1 次,持续 4 周。采用超声心动图检测小鼠心功能:左室射血分数 (LVEF) 、左室短轴缩短率 (LVFS) 、左室舒张末期内径 (LVEDD) 、左室收缩末期内径(LVESD); HE 染色法观察小鼠心脏组织病理变化;qRT-PCR 法检测心脏组织中 BNP mRNA 表达水平;Western Blot、Jess 法检测心脏组织中 PLN、p-Thr17-PLN、p-Ser16-PLN、肌浆网钙 ATP 酶 2a (SERCA2a)、蛋白激酶 A (PKA)、p-PKA、钙离子/钙调蛋白依赖性蛋白激酶Ⅱ (CaMKⅡ)、p-CaMKⅡ蛋白表达水平,计算SERCA2a/PLN 蛋白表达比值;定磷法检测心脏组织中 SERCA2a 的活性。结果 与假手术组比较,模型组小鼠的 LVEF、LVFS 显著降低 (P<0.01),LVEDD、LVESD 显著升高 (P<0.01);HE 染色显示心肌纤维断裂、排列紊乱,伴有炎性细胞浸润;心脏组织中 BNP mRNA 表达水平显著升高 (P<0.01);心脏组织中 p-Thr17-PLN、p-Ser16-PLN、p-PKA 蛋白表达水平均显著下降(P<0.01),p-CaMKⅡ蛋白表达水平显著升高(P<0.01),SERCA2a/PLN 蛋白表达比值及 SERCA2a 活性显著降低 (P<0.01)。与模型组比较,心康方中、高剂量组小鼠的 LVEF、LVFS 显著升高 (P<0.01),LVEDD、LVESD 显著降低 (P<0.01);HE 染色显示心脏组织病理损伤明显改善;心脏组织中 BNP mRNA 表达水平显著下降 (P<0.01);心脏组织中 p-Thr17-PLN、p-Ser16-PLN、p-PKA 蛋白表达水平均显著升高 (P<0.01),p-CaMKⅡ蛋白表达水平明显降低 (P<0.05),SERCA2a/PLN 蛋白表达比值及 SERCA2a 活性显著升高 (P<0.01)。结论 心康方可以有效改善心力衰竭小鼠的心功能,可能与其提高心脏组织受磷蛋白磷酸化水平有关。
[Key word]
[Abstract]
Objective To explore the mechanism of Xinkang Prescription (Descurainiae Semen Lepidii Semen,Armeniacae Semen Amarum, Poria, Astragali Radix, Citri Reticulatae Pericarpium, Sparanii Rhizoma) for purging the lung and promoting diuresis in treating heart failure by regulating phosphorylation of phospholamban(PLN). Methods Forty-eight C57BL/6J mice were randomly divided into sham-operation group,model group,low-,medium- and high- dose Xinkang Prescription groups(0.455,0.91,1.82 g•kg-1),as well as Entresto group(25 mg•kg-1),with eight mice in each group. The model of ischemic heart failure was established by ligating the left anterior descending coronary artery in mice. After the model was successfully replicated, mice were orally administered with the above-mentioned dosages of Xinkang Prescription and Entresto once a day for four weeks,while sham-operation group and model group were given 0.9% sodium chloride solution by gavage at the same time. Echocardiography was used to detect the cardiac function of the mice in each group,including left ventricular ejection fraction (LVEF),left ventricular fractional shortening (LVFS),left ventricular end-diastolic dimension(LVEDD) and left ventricular end systolic diameter (LVESD). Hematoxylin-eosin (HE) staining was used to observe the pathological changes in cardiac tissue of mice. qRT-PCR was used to detect the mRNA expression of BNP. Western Blot and Jess were used to detect the expression of PLN, p-Thr17-PLN, p-Ser16-PLN,sarcoplasmic reticulum calcium ATPase 2a (SERCA2a),protein kinase A (PKA),p-PKA,Ca2+/calmodulin-dependent kinaseⅡ (CaMKⅡ) and p-CaMKⅡin cardiac tissue,and to calculate the ratio of SERCA2a/PLN. The SERCA2a activity was determined by the inorganic phosphorus method.Results Compared with the sham-operation group,the model group showed a significant decrease in LVEF and LVFS(P<0.01) and a significant increase in LVEDD and LVESD (P<0.01). HE staining showed the fibril of cardiac muscle broke and disarranged,accompanied by inflammatory cell infiltration. The mRNA expression of BNP was significantly up-regulated (P<0.01),and the protein expressions of p-Ser16-PLN,p-Thr17-PLN,p-PKA,the ratio of SERCA2a/PLN and SERCA2a activity were significantly down-regulated (P<0.01), while the expression of p-CaMK Ⅱ was up-regulated (P<0.01). Compared with the model group, LVEF and LVFS in medium- , high- dose Xinkang Prescription groups were significantly increased(P<0.01),while LVEDD and LVESD were significantly decreased(P<0.01). HE staining showed significant improvement in the pathological damage of cardiac tissue. The expression level of BNP was significantly decreased (P<0.01),while the protein expressions of p-Ser16-PLN,p-Thr17-PLN,p-PKA,the ratio of SERCA2a/PLN and SERCA2a activity were significantly increased (P<0.01) . The protein expression of p-CaMKⅡ was remarkably decreased(P<0.05). Conclusion Xinkang Prescription can effectively improve cardiac function of mice with heart failure,which may be related to enhance phosphorylation levels of phospholamban.
[中图分类号]
R285.5
[基金项目]
国家自然科学基金项目 (82174316); 广东省中医药管理局科研项目 (20211406);东莞市社会发展科技项目 (20211800904402)。