Galectin-3抑制剂通过降低Gal-3的表达和心肌纤维化改善大鼠缺血性心力衰竭的机制研究

Galectin-3 inhibitors improve the mechanism of ischemic heart failure in rats by reducing the expression of Gal-3 and myocardial fibrosis.

目的探讨半乳糖凝集素3(Gal-3)抑制剂通过降低Gal-3的表达和心肌纤维化改善大鼠缺血性心力衰竭的机制研究。方法选择45只6~8周无特定病原体级雄性Wistar大鼠为研究对象,采用永久性结扎左冠状动脉前降支诱发缺血性心力衰竭大鼠模型,然后根据实验目的将大鼠分为对照组(假手术大鼠)、模型组(模型大鼠)和抑制剂组(模型大鼠),每组15只。对照组假手术大鼠给予10 mg/kg 0.9%氯化钠溶液灌胃,抑制剂组则在模型组基础上给予0.9%氯化钠溶液中添加0.15 mg·kg^(-1)·d^(-1)的柑橘果胶灌胃,连续4周。通过蛋白质印迹分析Gal-3、内质网钙离子结合蛋白(RCN-3)、反丁烯二酸酶、Ⅰ型胶原和Ⅲ型胶原的蛋白表达。通过磁共振成像测量大鼠的射血分数,通过压力容量导管测量左心室收缩末期(LVESPVR)和舒张末期压力-容积关系(LVEDPVR)。通过实时聚合酶链反应分析大鼠心肌中C-反应蛋白(CRP)、白细胞介素(IL)-1β、IL-6、转化生长因子-β(TGF-β)及结缔组织生长因子(CTGF)的mRNA表达。通过测定试剂盒检测大鼠心脏谷胱甘肽(GSH)含量和过氧化氢酶(CAT)活性。结果与对照组相比,模型组Gal-3蛋白表达、LVEDPVR、CRP、IL-1β、IL-6、TGF-β和CTGF的mRNA表达、Ⅰ型胶原和Ⅲ型胶原蛋白表达均显著升高,RCN-3和反丁烯二酸酶蛋白表达、LVESPVR、左心室射血分数、GSH含量及CAT活性均显著降低,差异均有统计学意义(P<0.05);而与模型组相比,抑制剂组Gal-3蛋白表达、LVEDPVR、CRP、IL-1β、IL-6、TGF-β和CTGF的mRNA表达、Ⅰ型胶原和Ⅲ型胶原蛋白表达均显著降低,RCN-3和反丁烯二酸酶蛋白表达、LVESPVR、左心室射血分数、GSH含量及CAT活性均显著升高,差异均有统计学意义(P<0.05)。结论Gal-3抑制剂可影响氧化还原途径,并通过减少Gal-3、Ⅰ型胶原和Ⅲ型胶原及炎症因子的水平,从而改善缺血性心力衰竭大鼠的心肌纤维化及心功能。

Objective To explore the mechanism of galectin-3(Galectin-3,Gal-3)inhibitors by reducing the expression of Gal-3 and myocardial fibrosis in improving ischemic heart failure in rats.Methods Forty-five 6 to 8-week-old SPF male Wistar rats were selected as the research objects,and a rat model of ischemic heart failure induced by permanent ligation of the left anterior descending coronary artery was used.Then,according to the purpose of the experiment,the rats were divided into control group(sham-operated rats),model group(model rats)and inhibitor group(model rats).The control group and sham-operated rats were given 10 mg/kg 0.9%sodium chloride solution by gavage,and the inhibitor group was given normal saline plus 0.15 mg·kg^(-1)·d^(-1) citrus pectin on the basis of the model group for 4 consecutive weeks.The protein expression of Galectin-3,RCN-3,fumarase,typeⅠcollagen and typeⅢcollagen was analyzed by Western blotting.The ejection fraction of rats was measured by magnetic resonance imaging,and the LV end-systolic and end-diastolic pressure-volume relationship was measured by a pressure-volume catheter.The mRNA expression of inflammatory factors CRP,IL-1β,IL-6,TGF-βand CTGF in rat myocardium was analyzed in real time by PCR.The GSH content and CAT activity of rat heart were detected by the assay kit.Results Compared with the control group,the expression of Gal-3 protein,LVEDPVR,CRP,IL-1β,IL-6,TGF-βand CTGF mRNA expression,and the expression of typeⅠcollagen and typeⅢcollagen in the model group were significantly increased,RCN-3 and fumarase protein expression,LVESPVR,LV ejection fraction,GSH content and CAT activity were all significantly reduced,the differences were statistically significant(P<0.05).Compared with the model group,the expression of Gal-3 protein,LVEDPVR,CRP,IL-1β,IL-6,TGF-βand CTGF mRNA,the expression of typeⅠcollagen and typeⅢcollagen expression in the inhibitor group were all significantly reduced,RCN-3 and fumarase protein expression,LVESPVR,LV ejection fraction,GSH content and CAT activity were significantly increased,the differences were statistically significant(P<0.05).Conclusion Gal-3 inhibitors can affect the redox pathway and reduce the levels of Gal-3,typeⅠcollagen,typeⅢcollagen and inflammatory factors,thereby improving myocardial fibrosis and cardiac function in rats with ischemic heart failure.