DCA-TGR5轴通过促进血管新生改善糖尿病心肌缺血再灌注损伤

    DCA-TGR5 axis-mediated angiogenesis attenuates diabetic myocardial ischemia-reperfusion injury

    • 摘要:
      目的 探索糖尿病合并心肌缺血再灌注损伤(MI/RI)时血浆胆汁酸池的变化及脱氧胆酸(DCA)在糖尿病MI/RI中发挥的作用及机制。
      方法 通过超高效液相色谱串联质谱法(UHPLC-MS/MS)对C57BL/6J小鼠血浆进行胆汁酸靶向代谢组学分析。在体实验利用超声评估小鼠心功能,Masson染色评估小鼠心肌组织纤维化,CD31染色评估小鼠心脏血管新生情况。体外实验利用成管实验检测血管内皮细胞血管新生能力,并结合RNA-Seq、实时定量PCR及Western blot验证下游机制。
      结果 血浆胆汁酸靶向代谢组学分析发现,相比于单纯MI/RI小鼠,糖尿病MI/RI小鼠血浆DCA水平显著降低(P<0.01)。外源补充DCA显著改善糖尿病MI/RI小鼠心脏功能及心肌纤维化,并促进心肌组织血管生成(P<0.01)。体外实验发现DCA能够促进血管内皮细胞成管(P<0.01)。机制研究发现DCA通过激活TGR5上调下游系列促血管新生分子促进血管新生,发挥心肌保护作用。
      结论 糖尿病合并MI/RI中, DCA水平显著降低加重心肌易损性;激活DCA-TGR5信号可促进微血管新生并改善损伤,为代谢干预提供新靶点。

       

      Abstract:
      AIM This study investigated alterations in the plasma bile acid pool during myocardial ischemia/reperfusion injury (MI/RI) in diabetes and explored the role and mechanism of deoxycholic acid (DCA) in diabetic MI/RI.
      METHODS  Plasma bile acids from C57BL/6J mice were profiled using targeted metabolomics via ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).In vivocardiac function was assessed by echocardiography, myocardial fibrosis by Masson's trichrome staining, and cardiac angiogenesis by CD31 immunohistochemistry.In vitrotube formation assays evaluated the angiogenic capacity of vascular endothelial cells. RNA sequencing (RNA-Seq), quantitative real-time PCR (qRT-PCR), and Western blotting were employed to elucidate downstream mechanisms.
      RESULTS  Targeted bile acid metabolomics revealed a significant decrease in plasma DCA levels (P<0.01) in diabetic MI/RI mice compared to non-diabetic MI/RI mice. Exogenous DCA supplementation markedly improved cardiac function, reduced myocardial fibrosis (P<0.01), and enhanced angiogenesis (P<0.01) in diabetic MI/RI mice. In vitro, DCA significantly promoted endothelial cell tube formation (P<0.01). Mechanistic studies demonstrated that DCA exerts its cardioprotective effects by activating the TGR5 receptor, leading to the upregulation of a cascade of pro-angiogenic molecules and enhanced angiogenesis.
      CONCLUSION  Impaired deoxycholic acid (DCA) signaling worsens cardiac susceptibility in diabetes with MI/RI. Therapeutic activation of the DCA-TGR5 pathway enhances microvascular neovascularization and mitigates myocardial damage, revealing a metabolic intervention strategy.

       

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