Time of exercise differentially impacts bone growth in mice.

Although physical training has been shown to improve bone mass, the time of day to exercise for optimal bone growth remains uncertain. Here we show that engaging in physical activity during the early active phase, as opposed to the subsequent active or rest phase, results in a more substantial increase in bone length of male and female mice. Transcriptomic and metabolomic methodologies identify that exercise during the early active phase significantly upregulates genes associated with bone development and metabolism. Notably, oxidative phosphorylation-related genes show a rhythmic expression in the chondrification centre, with a peak at the early active phase, when more rhythmic genes in bone metabolism are expressed and bone growth is synergistically promoted by affecting oxidative phosphorylation, which is confirmed by subsequent pharmacological investigations. Finally, we construct a signalling network to predict the impact of exercise on bone growth. Collectively, our research sheds light on the intricacies of human exercise physiology, offering valuable implications for interventions.

Effect of paeoniflorin on cardiac remodeling in chronic heart failure rats through the transforming growth factor ß1/Smad signaling pathway.

BACKGROUND: Cardiac remodeling is an important mechanism for the occurrence and development of chronic heart failure (CHF). Paeoniflorin (Pae) is the main active ingredient of Chinese herbaceous peony and has novel anti-inflammatory effect. This study was conducted to assess the effects and mechanisms of Pae on cardiac remodeling in CHF rats. METHODS: A cardiac remodeling rat model was induced by isoprenaline (Iso). Pae (20 µg/kg/d) was administrated to CHF rats for six weeks. Cardiac ultrasound was used to assess the structure and function of CHF rats. Collagen volume fraction (CVF) and perivascular collagen volume area of myocardial tissues were calculated. With real-time polymerase chain reaction and Western blot, the protein and mRNA levels of transforming growth factor ß1 (TGF-ß1) and Smad3 were detected. RESULTS: Compared to Iso group, Pae can alleviate cardiac remodeling and improve cardiac function in CHF rats. The levels of CVF and perivascular collagen volume area reduced in Pae group (P<0.05). The expression of TGF-ß1 and Smad3 protein decreased in Pae and Cap group (P<0.05). Further, the expression of TGF-ß1 and Smad3 mRNA also decreased markedly in the Pae group (P<0.05). CONCLUSIONS: Pae could attenuate cardiac remodeling and improve cardiac function in CHF rats. The potential mechanism for the cardioprotective effect of Pae may be highly associated with the down-regulating of TGF-ß1/Smad signaling pathway.