基于β1integrin/FAK/CSK信号通路探讨优化新生脉散方对肥厚心肌的机械转导机制研究

Clinically, long-term increased myocardial afterload can lead to cardiac hypertrophy-concomitant with changed mechanical properties of myocardial viscoelasticity and rigidity that can affect myocardial instablility and ventricular filling, further can cause diastolic heart failure.β1Integrin/FAK/CSK pathway is not only the key of mechanical instablility, but also the key path from stimulation of afterload transform to mechanical instablility. Previous studies have shown that You Hua Xin Sheng Mai San Decoction（YHXSMSD）can improve the longitudinal strain, radial strain and cir-cumferential strain in the short axis direction of the local segmental myocardium to improve the diastolic function and the degree of cardiac hypertrophy. The character of myocardial mechanics as the starting point in this study, thoracic aorta rats and hypertrophic cardiomyocytes induced by mechanical stretch are research objects, based on β1integrin/FAK/CSK signal transduction pathway, using the technique of speckle tracking、Micropipette aspiration、Bio-AC、RT-PCR and Western blotting, to definite the effects of YHXSMSD on the expression of β1integrin,FAK phosphorylation level、CSK, to ensure the mechanism of realizing maintaining the balance of cell mechanics and improve cardiac diastolic function, in order to provide a new reference for the study of myocardial hypertrophy of traditional Chinese medicine, and scientific basis for the clinical application of YHXSMSD.

长期后负荷增加引起心肌肥厚伴生的心肌粘弹性及刚性等应力特性改变直接影响心肌顺应性及心室充盈，是导致舒张性心力衰竭的病理生理基础。β1Integrin/FAK/CSK轴是将后负荷刺激转化至力学失稳的关键通路，是认识心肌顺应性改变的关键环节。团队前期研究初步显示，优化新生脉散方可改善局部各节段心肌在长轴方向的纵向应变、径向应变和短轴方向的环向应变，通过力学调节改善心衰患者心功能及心肌肥厚程度。本研究以心肌力学特性为切入点，以胸主动脉缩窄大鼠心肌组织及机械牵张诱导肥大心肌细胞为研究对象，基于β1integrin/FAK/CSK信号通路，采用斑点追踪、微管吸吮、RT-PCR、Western blotting等技术，揭示优化新生脉散方通过抑制β1integrin、CSK表达及FAK磷酸化，实现维持细胞力学性能、改善心脏舒张功能的机械转导机制，为优化新生脉散方防治心肌肥厚提供科学依据。

团队前期研究初步显示，优化新生脉散方可通过力学调节改善心衰患者心功能及心肌肥厚程度。长期后负荷增加引起心肌肥厚伴生的心肌粘弹性等应力特性改变直接影响心肌顺应性及心室充盈，是导致舒张性心力衰竭的病理生理基础。β1Integrin/FAK/CSK轴是将后负荷刺激转化至力学失稳的关键通路，是认识心肌顺应性改变的关键环节。本研究以心肌力学特性为切入点，以胸主动脉缩窄大鼠心肌组织及机械牵张诱导肥大心肌细胞为研究对象，基于β1integrin/FAK/CSK信号通路，采用HE染色、MASSON染色发现优化新生脉散方可改善心肌肥厚大鼠心肌纤维化的程度，采用超声心动图、斑点追踪、生物力学技术发现优化方可提高大鼠心功能及心肌组织的力学性能。同时按照计划，采用免疫荧光检测心肌细胞骨架蛋白的表达及分布，微管吸吮明确细胞粘弹性的改变。采用RT-PCR、Western Blot等方法，揭示优化新生脉散方通过抑制β1integrin、CSK表达及FAK磷酸化，实现维持细胞力学性能、改善心脏舒张功能的机械转导机制，为优化新生脉散方防治心肌肥厚提供科学依据。同时探索性的对心肌肥厚大鼠血清外泌体蛋白组学进行研究，发现优化新生脉散方药效相关的SUSD2标志蛋白作为心肌细胞表型变化特征的蛋白标记物，可能作为早期诊断心肌肥厚及心衰的标记物。优化新生脉散方通过整合素与细胞骨架蛋白转导调节心肌细胞骨架的机制来干预心肌肥厚的发展，从而有望为今后治疗心肌肥厚提供解决思路。