Resveratrol is a polyphenol known to have metabolic as well as circadian effects. However, there is little information regarding the metabolic and circadian effect of resveratrol on muscle cells. We sought to investigate the metabolic impact of resveratrol throughout the circadian cycle to clarify the associated signaling pathways. C2C12 myotubes were incubated with resveratrol in the presence of increasing concentrations of glucose, and metabolic and clock proteins were measured for 24 h. Resveratrol led to SIRT1, AMPK and PP2A activation. Myotubes treated with increasing glucose concentrations showed higher activation of the mTOR signaling pathway. However, resveratrol did not activate the mTOR signaling pathway, except for P70S6K and S6. In accordance with the reduced mTOR activity, resveratrol led to advanced circadian rhythms and reduced levels of pBMAL1 and CRY1. Resveratrol increased myogenin expression and advanced its rhythms. In conclusion, resveratrol activates the SIRT1-AMPK-PP2A axis, advances circadian rhythms and induces muscle development.

This paper examines the dynamics of circulating hormone changes connected with reproduction in geese during the annual period related to gonad morphometry. One hundred geese were examined. The levels of prolactin (PRL), triiodothyronine (T3), thyroxine (T4), testosterone (T), progesterone (P4) and estradiol (E2) were estimated. In both sexes, PRL level patterns fit a quadratic trend with elevations in the post-breeding and the second half of the breeding–laying periods. During these periods, differences in the PRL level between sexes were noted. In ganders, increased PRL levels during the laying period occurred earlier compared to in female geese. Cubic trends for T and E2 in ganders and quadratic for T, P4, and E2 in female geese were observed. PRL was negatively correlated with T in both sexes and with P4 and E2 in female geese. A higher level of T3 and variation in T4 in ganders with a quartic trend in ganders vs. a quadratic in female geese were noted. Patterns of PRL, T, and E2 suggested that the breeding–laying period in ganders may be shorter than in female geese. These findings will be used to explore experimental manipulations of the endocrine axis to increase synchronisation of both sexes.

Parental exposure to insults was initially considered safe if stopped before conception. In the present investigation, paternal or maternal preconception exposure to the neuroteratogen chlorpyrifos was investigated in a well-controlled avian model (Fayoumi) and compared to pre-hatch exposure focusing on molecular alterations. The investigation included the analysis of several neurogenesis, neurotransmission, epigenetic and microRNA genes. A significant decrease in the vesicular acetylcholine transporter (SLC18A3) expression was detected in the female offspring in the three investigated models: paternal (57.7%, p < 0.05), maternal (36%, p < 0.05) and pre-hatch (35.6%, p < 0.05). Paternal exposure to chlorpyrifos also led to a significant increase in brain-derived neurotrophic factor (BDNF) gene expression mainly in the female offspring (27.6%, p < 0.005), while its targeting microRNA, miR-10a, was similarly decreased in both female (50.5%, p < 0.05) and male (56%, p < 0.05) offspring. Doublecortin’s (DCX) targeting microRNA, miR-29a, was decreased in the offspring after maternal preconception exposure to chlorpyrifos (39.8%, p < 0.05). Finally, pre-hatch exposure to chlorpyrifos led to a significant increase in protein kinase C beta (PKCß; 44.1%, p < 0.05), methyl-CpG-binding domain protein 2 (MBD2; 44%, p < 0.01) and 3 (MBD3; 33%, p < 0.05) genes expression in the offspring. Although extensive studies are required to establish a mechanism–phenotype relationship, it should be noted that the current investigation does not include phenotype assessment in the offspring.

A high-fat (HF) diet disrupts metabolic homeostasis and impairs peripheral circadian rhythms in key metabolic tissues. β-Hydroxybutyrate (BHB), a major circulating ketone body, functions not only as an energy substrate but also as a signaling metabolite regulating nutrient-sensing and inflammatory pathways. However, its role in modulating metabolic–circadian interactions under conditions of nutrient excess remains unclear. In this study, we investigated whether BHB supplementation influences metabolic signaling and circadian clock oscillations in liver, skeletal muscle and adipose tissue under chow and HF conditions. Male C57BL/6 mice were fed chow or HF with or without BHB supplementation (500 mg/kg body weight in the diet) for 7 weeks. Metabolic parameters were assessed by indirect calorimetry, and tissues were collected every 4 h across the circadian cycle. HF feeding increased body weight and adiposity (p < 0.01), reduced AMPK activation, enhanced AKT/mTOR signaling, elevated NF-κB levels and dampened clock gene rhythmicity. BHB supplementation significantly decreased food intake in HF-fed mice (p < 0.01) and partially reversed several molecular alterations in a tissue-specific manner. In skeletal muscle and adipose tissue, BHB increased AMPK activation and reduced mTOR and NF-κB signaling (p < 0.05), whereas hepatic effects were more modest. Notably, BHB modulated circadian gene expression, restoring aspects of rhythmic amplitude and/or phase, particularly in adipose tissue. These findings may indicate that BHB supplementation modulates nutrient-sensing pathways and partially restores peripheral circadian rhythms under HF conditions. While some effects may be influenced by reduced energy intake, BHB may serve as a metabolic signal linking nutrient status to circadian regulation.

β-hydroxy-β-methylbutyrate (HMB), a bioactive metabolite of leucine, is widely recognized for its anabolic and anti-catabolic effects in skeletal muscle. However, the molecular mechanisms underlying these effects, particularly in relation to circadian regulation, remain incompletely understood. Here, we investigated the impact of HMB on dexamethasone-induced muscle atrophy in C2C12 myotubes, with a focus on anabolic signaling and circadian clock regulation. C2C12 myotubes were treated with HMB or HMB after dexamethasone-induced atrophy. HMB treatment significantly improved cell viability, surface area and fiber diameter by reducing expression of CBL-B, MuRF1 and Atrogin1, key mediators of muscle proteolysis, and increasing myogenin expression compared with atrophic conditions. While HMB did not activate AKT or mTOR, it robustly increased phosphorylation of P70S6K and S6 through a phospholipase D (PLD)-dependent mechanism. HMB restored disrupted circadian clock gene expression induced by dexamethasone, including normalization of expression patterns. HMB also enhanced circadian rhythmic amplitude and advanced phase timing, indicating improved clock robustness. These findings identify circadian regulation as a novel target of HMB action and demonstrate that HMB preserves muscle homeostasis through coordinated modulation of anabolic signaling and intrinsic circadian machinery. This study provides mechanistic insight into how HMB protects against muscle atrophy and highlights circadian regulation as an important contributor to skeletal muscle health.