Regulation of mitochondrial autophagy by lncRNA MALAT1 in sepsis-induced myocardial injury.

Background: Sepsis-induced myocardial injury (SIMI) is a severe complication of sepsis, contributing significantly to mortality. Mitochondrial dysfunction and dysregulated autophagy are implicated in SIMI pathogenesis. Long non-coding RNA MALAT1 has been associated with various diseases, including sepsis, but its role in SIMI remains unclear.

Objective: This study aimed to investigate the role of lncRNA MALAT1 in SIMI, specifically in the regulation of mitochondrial autophagy.

Methods: A sepsis-induced cardiomyopathy model was established in mice, and the cardiac tissues were analyzed. The expression of lncRNA MALAT1 was modulated and its effects on mitochondrial autophagy, myocardial injury, inflammation, and apoptosis were assessed. Furthermore, the interaction between MALAT1 and miR-146a was explored, as well as the involvement of the TLR4/NF-kB/MAPK signaling pathway.

Results: Activation of mitochondrial autophagy by urolithin A (UA) alleviated SIMI, inflammation, and cardiac dysfunction. Downregulation of MALAT1 enhanced mitochondrial autophagy, stabilized the mitochondrial membrane potential, and inhibited mitochondrial reactive oxygen species (ROS) production, leading to improved cell viability and reduced myocardial injury. Furthermore, MALAT1 interacted with miR-146a, and their modulation influenced mitochondrial autophagy, myocardial injury, and inflammation. The TLR4/NF-kB/MAPK signaling pathway was implicated in these processes.

Conclusion: Our findings suggest that lncRNA MALAT1 plays a crucial role in SIMI by modulating miR-146a-mediated mitochondrial autophagy and the TLR4/NF-kB/MAPK signaling pathway. These results provide new insights into the pathogenesis of SIMI and potential therapeutic targets.