Expression characteristics of peripheral blood miR-146a and TLR4 in septic cardiomyopathy: Correlations with myocardial injury markers and cardiac function classification

Abstract

Objective: To investigate the expression levels of peripheral blood microRNA-146a (miR-146a) and Toll-like receptor 4 (TLR4) in patients with septic cardiomyopathy (SCM), and their association with myocardial injury markers and cardiac function classification.

Methodology: This retrospective study included clinical data from 92 patients with SCM who were hospitalized at Shanghai Tongren Hospital between January 2023 and December 2025 (study group). The clinical data of 92 patients with uncomplicated sepsis admitted during the same period were used as the control group. Fasting peripheral venous blood samples were collected from all patients to measure the levels of miR-146a, TLR4, and myocardial injury markers (cTnI, CK-MB, BNP), and to assess cardiac function classification. The levels of miR-146a, TLR4, and myocardial injury markers were compared between the study and control groups. Additionally, miR-146a and TLR4 levels were evaluated in patients with different cardiac function classifications. The correlation between miR-146a, TLR4, myocardial injury markers, and cardiac function classification was further analyzed.

Results: The levels of miR-146a and TLR4 in the study group were higher than those in the control group (miR-146a: 3.26±0.85 vs. 1.05±0.32, P<0.001; TLR4: 68.52±12.36 ng/L vs. 32.18±8.45 ng/L, P<0.001). The levels of cTnI, CK-MB, and BNP in the study group were also higher than those in the control group (cTnI: 0.85±0.26 ng/mL vs. 0.08±0.03 ng/mL, P<0.001; CK-MB: 45.32±10.25 U/L vs. 15.68±4.36 U/L, P<0.001; BNP: 1256.38±325.64 pg/mL vs. 185.42±65.31 pg/mL, P<0.001). There were significant differences in miR-146a and TLR4 levels among patients with different cardiac function classifications (P<0.05). The levels of miR-146a and TLR4 were significantly positively correlated with myocardial injury markers and cardiac function classification. In particular, the correlation coefficients of TLR4 with cTnI and cardiac function classification were 0.702 and 0.817, respectively, while those of miR-146a were 0.718 and 0.823, respectively (all P<0.001).

Conclusion: The expression levels of peripheral blood miR-146a and TLR4 in patients with SCM are significantly elevated, and their expression levels positively correlate with the levels of myocardial injury markers and the severity of cardiac function impairment.