Temporal Variations in the Orexigenic Hormone Asprosin and Its Receptor: Implications for Energy Homeostasis and...

Circadian misalignment caused by altered feeding behaviors disrupts metabolic homeostasis and endocrine rhythms. Asprosin, a fasting-induced adipokine derived from the cleavage of profibrillin-1 (FBN1), stimulates hepatic glucose release and activates hypothalamic pathways that regulate appetite. Although asprosin's metabolic functions are increasingly recognized, its temporal expression patterns and interactions with peripheral and central tissues remain insufficiently explored. This study aimed to investigate the circadian expression patterns of the orexigenic hormone asprosin and its receptor OLFR734 in metabolically relevant tissues and the olfactory bulb of male Balb/c mice.

Male Balb/c mice (n = 28) were evaluated at defined circadian time points. Quantitative real-time PCR, immunohistochemistry, and ELISA were used to assess the gene and protein expressions of asprosin and OLFR734, together with circulating levels of asprosin, glucose, and melatonin.

Asprosin and OLFR734 showed significant diurnal oscillations (p <0.05-p <0.0001). Peak serum asprosin levels coincided with nocturnal melatonin elevation and reduced glucose concentrations. Tissue-specific variations were observed in both central and peripheral expression patterns.

These results demonstrate that the asprosin-OLFR734 axis manifests a pronounced circadian rhythmicity, underscoring its pivotal role in the temporally coordinated regulation of appetite and glucose homeostasis. Such rhythmicity offers critical insight into the intricate endocrine mechanisms that govern nocturnal metabolic adaptations and provides a conceptual framework for future research on the temporal orchestration of energy balance and metabolic function.