Hoxa5 alleviates adipose tissue metabolic distortions in high-fat diet mice associated with a reduction in MERC.

Background: Mitochondria-endoplasmic reticulum membrane contact (MERC) is an important mode of intercellular organelle communication and plays a crucial role in adipose tissue metabolism. Functionality of Hoxa5 is an important transcription factor involved in adipose tissue fate determination and metabolic regulation, but the relationship between Hoxa5 and MERC is not well understood.

Results: In our study, we established an obesity model mouse by high-fat diet (HFD), induced the alteration of Hoxa5 expression by adenoviral transfection, and explored the effect of Hoxa5 on MERC dysfunction and metabolic distortions of adipose tissue with the help of transmission electron microscopy, calcium ion probe staining, and other detection means. The results showed Hoxa5 was able to reduce MERC production, alleviate endoplasmic reticulum stress (ERS) and calcium over-transport, and affect cGAS-STING-mediated innate immune response affecting adipose tissue energy metabolism, as well as affect the AKT-IP3R pathway to alleviate insulin resistance and ameliorate metabolic distortions in adipose tissue of mice.

Conclusions: Our results suggest that Hoxa5 can ameliorate high-fat diet-induced MERC overproduction and related functional abnormalities, in which finding is expected to provide new ideas for the improvement of obesity-related metabolic distortions.