Targeting IDH1 with Urolithin A protects against sepsis-induced myocardial injury by attenuating apoptosis

Sepsis is a life-threatening condition characterized by a dysregulated host response to infection, frequently leading to multiple organ dysfunction and high mortality rates. Urolithin A (UA), a natural metabolite derived from gut microbiota, has shown anti-inflammatory, mitophagy-promoting and other beneficial properties, yet its protective mechanisms against sepsis-induced organ injury remain to be elucidated. We systematically evaluated the therapeutic potential of UA using a cecal ligation and puncture (CLP)-induced rat model. Comprehensive assessments including survival analysis, inflammatory cytokine profiling, organ coefficient measurements, histopathological examination, echocardiography, myocardial injury markers, and immunohistochemistry revealed that UA provided the most significant protection against sepsis-induced myocardial injury (SIMI) among all examined organs. Through integrated approaches combining network pharmacology, molecular docking, and cellular thermal shift assay (CETSA), we identified isocitrate dehydrogenase 1 (IDH1) as a direct molecular target of UA. Additional in vitro investigations using lipopolysaccharide (LPS)-stimulated H9C2 cells demonstrated that UA significantly attenuated apoptosis, as confirmed by flow cytometry analysis. The anti-apoptotic effect was further verified in myocardial tissues through Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) staining. Additionally, q-PCR, Western blot, and other experiments were performed both in vivo and in vitro to assess the downstream signaling. Furthermore, partial knockdown of IDH1 (shIDH1) in H9C2 cells substantially abolished the cardioprotective effects of UA, confirming the crucial role of IDH1 in mediating UA's therapeutic actions. Our studies revealed that UA directly activated IDH1 without affecting its expression, subsequently modulating the Bcl-2-mediated apoptotic pathway. These findings suggest that UA supplementation may represent a promising therapeutic strategy for sepsis management and warrant further clinical investigation.