Acr, short for autophagy-related circular RNA, is a circular RNA that has been reported to be involved in protecting myocardial tissues from injury and participating in chronic heart failure (CHF) [1]. Circular RNAs are a class of non-coding RNAs with a closed-loop structure, which can play regulatory roles in various biological processes, potentially by acting as miRNA sponges, regulating transcription, or interacting with proteins.

In the context of CHF, Acr expression was found to be downregulated. Kaplan-Meier and multivariate Cox regression analysis indicated that low Acr levels predicted the overall survival of CHF patients, and Acr was inversely correlated with miR-532 in plasma samples [1]. In cardiomyocytes, Acr increased miR-532 gene methylation to decrease its expression. Overexpression of Acr reduced the enhancing effects of miR-532 overexpression on cardiomyocyte apoptosis under hypoxic conditions, suggesting that Acr may suppress hypoxia-induced cardiomyocyte apoptosis by downregulating miR-532 via methylation [1].

In conclusion, Acr, as an autophagy-related circular RNA, is downregulated in CHF and may play a role in suppressing hypoxia-induced cardiomyocyte apoptosis through its regulation of miR-532. The study of Acr in the context of CHF provides insights into the molecular mechanisms underlying heart failure, potentially paving the way for new therapeutic strategies related to this disease [1].