NR4A1 Regulates Glycolysis in M1 Macrophages via the Wnt/β-Catenin Pathway to Affect Sepsis-Induced Myocardial Injury.

OBJECTIVE: Pro-inflammatory M1 macrophage impede myocardial repair, and glycolysis plays a role in the pathological process of myocardial injury induced by M1 macrophage polarization. This study aims to elucidate the molecular mechanism by which NR4A1 participates in sepsis‑induced myocardial injury (SIMI) through regulating glycolysis in M1 macrophages via the Wnt/β‑catenin pathway. METHODS: Glycolysis-related genes and SIMI-related datasets were downloaded from public database and subjected to bioinformatics analysis. A mouse model of SIMI was established using cecal ligation and puncture (CLP). M1 macrophage polarization was induced by LPS stimulation. Echocardiography was performed to evaluate left ventricular structure and function. Hematoxylin-eosin staining was conducted to assess histopathological changes in myocardial tissues. Immunofluorescence was performed to detect macrophage markers and NR4A1. ELISA was used to measure the secretion of inflammatory cytokines. Western blot and qRT-PCR were performed to detect macrophage markers, glycolysis markers, Wnt/β-catenin pathway-related proteins, and NR4A1. Cell migration was assessed via Transwell assay, lactate levels were determined via colorimetric assay, cardiomyocyte activity was assessed via CCK-8, cardiomyocyte apoptosis was evaluated by flow cytometry. RESULTS: Bioinformatics analysis identified NR4A1 as a glycolysis-related factor affecting SIMI. In myocardial tissues, CLP promoted macrophage aggregation, with more M1 macrophages than M2 macrophages, accompanied by decreased NR4A1 expression. LPS stimulation enhanced the expression of M1 macrophage markers and promoted glycolysis, while inhibiting the expression of NR4A1 and Wnt/β-catenin pathway-related proteins. In addition, LPS-treated macrophages reduced cardiomyocyte activity. NR4A1 overexpression in the LPS group reversed these effects. Furthermore, overexpression of GLUT1 in the LPS+oe-NR4A1 group promoted glycolysis in macrophages. GLUT1 overexpression also resulted in increased expression of M1 macrophage markers and enhanced glycolysis, but reduced cardiomyocyte activity. Moreover, inhibition of the Wnt/β-catenin pathway with ICG-001 in the LPS+oe-NR4A1 group increased the expression of M1 macrophage markers and enhanced glycolysis, while reduced cardiomyocyte activity. CONCLUSION: In summary, high expression of NR4A1 inhibits glycolysis in macrophages by activating the Wnt/β-catenin pathway, thereby affecting cardiomyocyte apoptosis mediated by M1 macrophage polarization.