Circ_0001084/miR-181c-5p/PTPN4 Axis Mitigates Cardiomyocyte Injury by Modulating the TLR4/NF-κB Pathway: Insights into Therapeutic Potential for Myocardial Reperfusion Injury.

Background: Myocardial ischemia/reperfusion (I/R) injury significantly impacts the recovery of ischemic heart disease patients. Non-coding RNAs, including miRNAs, have been increasingly recognized for their roles in regulating cardiomyocyte responses to hypoxia/reoxygenation (H/R) injury. miR-181c-5p, in particular, has been implicated in inflammatory and apoptotic processes, suggesting its potential involvement in exacerbating cellular damage. Methods: This study combined bioinformatic and experimental techniques to investigate myocardial injury. Gene expression data from the GEO database were analyzed, and HL-1 cardiomyocytes were used in a hypoxia/reoxygenation model to mimic reperfusion injury. Various molecular techniques have been applied to explore the underlying mechanisms, while statistical analyses have identified potential biomarkers and therapeutic targets. Results: This study revealed significant upregulation of miR-181c-5p in cardiomyocyte H/R injury models, which inversely affected PTPN4 expression and activated the TLR4/NF-κB signaling pathway. Overexpression of PTPN4 inhibited this pathway. Notably, circ_0001084 was identified as absorbing miR-181c-5p, reducing its interaction with PTPN4 and subsequent pathway activation. This suggests a novel therapeutic pathway for myocardial I/R injury treatment, highlighting the interplay between non-coding RNAs and cellular stress responses. Conclusion: circ_0001084 acts as a competing endogenous RNA for miR-181c-5p, enhancing PTPN4 expression and inhibiting the TLR4/NF-κB signaling pathway. These findings offer insights into the molecular mechanisms of myocardial I/R injury and potential therapeutic targets in ischemic heart disease.