基于galectin-3时序性变化和调控通路研究参附益心颗粒抗心肌纤维化的作用机制

Myocardial fibrosis is a chronic process that is a key factor in ventricular remodeling. Galectin-3, as an important regulator of myocardial fibrosis, is a new target for delaying or preventing myocardial fibrosis. Previous results showed that galectin-3 could regulate the mRNA expression of PI3K and Akt1, shenfu yixin granules (SF) could significantly downregulate the expression of galectin-3 mRNA in cultured fibroblasts induced by AngII and preventing ventricular remodeling.Those observations has led to hypothesis: SF delayed ventricular remodeling via galectin-3 pathway. To verify such hypothesis, rats of myocardial fibrosis model after acute myocardial infarction were established. Sham operation and galectin-3 blocker (N-Lac) group were used as control, The technique of western blotting, qRT-PCR were applied to measure protein and gene expression of galectin-3 to demonstrate the time sequential change of galectin-3 in the formation of myocardial fibrosis, measure galectin-3 downstream PI3K/Akt1 gene and protein expression to demonstrate the regulation of galectin-3 on its downstream proteins. Using captopril and N-Lac as control, SF alone or in combination with galectin-3 blockers, it was to explore the effect and mechanism of SF on myocardial fibrosis.

心肌纤维化是一个慢性过程，是导致心室重构的关键因素。galectin-3 作为心肌纤维化重要调节分子，是延缓或阻断心肌纤维化的新靶标。前期研究提示galectin-3对下游关键蛋白PI3K、Akt1有显著调节作用，参附益心颗粒（SF）能显著降低Ang II诱导肌成纤维细胞galectin-3 mRNA表达，抑制心室重构。推测：galectin-3在心肌纤维化过程中呈时序性变化，SF通过galectin-3介导的信号通路抗心肌纤维化。为验证假说，建立大鼠心梗后心肌纤维化模型，用N-Lac（galectin-3阻断剂）、假手术组做对照，测定不同时点galectin-3表达阐明其时序性变化；测定galectin-3下游关键蛋白的表达明确galectin-3对PI3K/Akt1信号通路的调控。以卡托普利、N-Lac作对照，SF单独或联合galectin-3阻断剂使用，阐明SF抗心肌纤维化作用机制。

本研究通过建立急性心肌梗死后心力衰竭大鼠模型，测定不同时点galectin-3的表达，明确galectin-3的时序性变化；其次采用实时定量RT-PCR和western blot技术考察了galectin-3对下游蛋白PI3K/Akt1的调控作用；再次建立急性心肌梗死后心力衰竭大鼠模型，阐释参附益心颗粒抗心肌纤维化的作用和机制。.结果表明，galectin-3在急性心肌梗死后心力衰竭大鼠模型中呈时序性变化趋势，同一时点，模型组大鼠galetin-3水平最高，假手术组和阻断剂组galectin-3水平明显低于模型组。不同时点，4周时模型组galectin-3水平最高。说明galectin-3在AMI后心衰大鼠中呈时序性变化，且在4周时达到高峰，此后呈下降趋势。以术后4周为切入点，观察galectin-3对下游关键蛋白磷酸化Akt1的表达，结果发现模型组磷酸化Akt1蛋白表达明显高于阻断剂组和假手术组。在上述研究的基础上，采用参附益心颗粒对急性心肌梗死术后心力衰竭大鼠进行干预，干预4周后发现参附益心颗粒干预组心肌纤维化程度明显较模型组减轻，射血分数有所提高，阻断剂组和SF-H组galectin-3蛋白较模型组下调，而p-AKT/AKT1蛋白表达上调，进而明确了参附益心颗粒抗心肌纤维化的作用及机制，且高剂量组效果更佳。.综上所述，galectin-3具有时序性变化趋势，通过激活Akt的磷酸化发挥作用；参附益心颗粒早期干预可通过调控galectin-3，激活PI3K/Akt1抑制心肌纤维化的进程，从而发挥心脏保护作用。