Forty-one degrees celsius enhances proliferation of chicken muscle satellite cells via mechanistic target of rapamycin activation and mitochondrial metabolism

Chicken muscle satellite cells (CMSCs) possess a self-renewal capacity and myogenic differentiation potential, making them valuable cellular resources for cultured meat production. Enhancing the proliferation rate of CMSCs is essential to improve production efficiency, and cellular proliferation is highly sensitive to changes in the culture temperature. Generally, the standard culture temperature for most cells is 37 °C. however, this does not reflect the physiological body temperature of chickens. In this study, we cultured CMSCs at 37, 39, 41, and 43 °C to determine the optimal temperature for proliferation and investigate the metabolic responses of cells under these conditions. Cell counting and CCK8 assays revealed that CMSCs cultured at 41 °C exhibited a significantly higher proliferation rate than those cultured at other temperatures. Furthermore, compared to the 37 °C control group, cells cultured at 41 °C showed enhanced mitochondrial function and increased adenosine triphosphate (ATP) production, accompanied by the upregulation of genes associated with the mechanistic target of rapamycin (mTOR) signaling pathway. Although reactive oxygen species (ROS) generation was elevated at 41 °C, no significant change in the expression of the antioxidant enzyme superoxide dismutase 1(SOD1) was observed, and the expression of Catalase decreased. Additionally, no significant differences were observed in the expression of apoptotic pathway-related factors. These findings suggest that 41 °C is the optimal temperature for promoting the proliferation and mitochondrial metabolism of CMSCs, providing insights into the optimization of culture conditions for cultured meat production.