Physiological temperature enhances proliferative capacity and protein production characteristics of chick satellite cells

Culture temperature is a critical factor influencing cellular metabolism and protein production. This study investigated the effects of culture temperature on the proliferation, differentiation, and nutritional profile of chick satellite cells. Cells isolated from chick embryos were cultured at 37 °C and 40 °C to evaluate their bioprocessing efficiency and protein characteristics. The results demonstrated that culturing cells at 40 °C significantly enhanced cell proliferation, as evidenced by increased cell numbers and a shortened population doubling time, without inducing chronic thermal toxicity. Regarding myogenic status, immunofluorescence analysis showed no significant differences in terminal differentiation markers between the two conditions. However, transcriptional analysis revealed that 40 °C upregulated the expression of myoblast determination protein and decreased the expression of paired box-7 compared to 37 °C. Furthermore, while the total protein content showed no significant differences between the two temperatures, the amino acid composition revealed qualitative distinctions: cells cultured at 37 °C exhibited higher levels of glycine and alanine, whereas those cultured at 40 °C showed higher levels of branched-chain amino acids, such as valine, isoleucine, and lysine. These findings suggest that 40 °C is an optimal culture temperature for the efficient expansion of chick satellite cells, providing a practical strategy for producing cell-derived protein materials.