Background: Progeny adipofibroblast cells, derived from mature bovine adipocytes, were used to determine their ability to redifferentiate into lipid-assimilating adipocytes. Methods: Traditional cell biology methods were used, including the expression of adipogenic markers such as peroxisome proliferator-activated receptor γ (PPARγ). Results: When exposed to medium supplemented with fetal bovine serum, but not horse serum, cells began to form structures reminiscent of foci. Horse serum-supplemented medium resulted in a slowed progression towards cell conversion to lipid-assimilating adipocytes. When analyzed, horse serum was found to contain more cortisol and insulin-like growth factor-1 as well as differing fatty acid ratios. Histological observations of the horse serum-treated cultures (alone), cultures treated with a traditional differentiation induction medium (dexamethasone, methylisobutylxanthine and insulin), treated with insulin with or without different lipid compounds, or treated with a PPARγ agonist (rosiglitazone) resulted in the presence of intracellular vesicles, of which some contained lipid and some did not. Vesicles that did not stain for lipid did not possess glycogen or other types of storage moieties even though the cells expressed cellular markers thereby deeming them to be differentiated adipocytes (PPARγ protein and mRNA were expressed by cells possessing vesicles as were hormone-sensitive lipase and lipoprotein lipase proteins). Non-lipid-filled intracellular vesicle walls possessed the structural protein perilipin. Conclusion: These results are supportive of the progeny adipofibroblasts representing a unique adipogenic model that displays protracted adipogenesis.
