Adipogenic differentiation of chicken epithelial oviduct cells using only chicken serum.

Chicken epithelial oviduct cells (COCs) are part of important supportive tissues in chicken reproductive organs responsible for secretion of the majority of chicken egg protein. In chickens, the biological process of adipocyte differentiation has been extensively studied in vitro using a number of cell types including a preadipocyte precursor cell line, a number of other undifferentiated cell lines, and chicken embryonic fibroblasts. On the contrary, adipogenic differentiation in epithelial cells has not yet been achieved. In our study, we induced COCs to differentiate into adipocytes using chicken serum at concentrations of 5% and 10%. After a 24-h culture period at 37°C in a humidified 5% CO(2) atmosphere, oviduct cell morphology changed dramatically through formation of lipid droplets, observed by Oil Red O staining. Also, chicken serum strongly induced 3T3-L1 preadipocyte cell differentiation into adipocyte. In addition, mRNA expression levels of peroxisome proliferator-activated receptor gamma, adipocyte fatty acid-binding protein (aP2), and CCAAT-enhancer-binding protein alpha were significantly increased 48 h after induction. These results suggest that COCs can be induced to differentiate into adipocyte-like cells. Moreover, through this study, we confirmed that chicken serum is an effective adipocyte differentiation-inducing agent. Our findings may provide a unique model for studying and applying chicken transdifferentiation and adipocyte differentiation.