Is All Fat Created Equal? A Comparative Study of Chondrogenesis Potential of Peri-Ovarian Adipose Tissues in Dogs

Osteoarthritis (OA) causes chronic pain and impaired mobility in dogs. Since current therapies cannot restore damaged articular cartilage, tissue engineering approaches offer promising therapeutic strategies. This study aimed to investigate whether peri-ovarian adipose tissue (POAT) represents a biologically competent and functionally relevant alternative source of mesenchymal stromal cells (MSCs) compared to subcutaneous adipose tissue (SAT). Samples were collected from five healthy and normal-weight Labrador Retrievers undergoing routine ovariectomy. MSCs were characterized according to the International Society for Cellular Therapy, including doubling time, growth curves, colony-forming unit assays, immunophenotyping, and trilineage differentiation potential. Chondrogenic differentiation was assessed through Alcian Blue staining and qPCR analysis of COL2A1, COL1A1, COL10A1, and SOX9 expression at multiple timepoints. MSCs derived from both adipose depots showed comparable mesenchymal characteristics, proliferative capacity, immunophenotypic profiles, and multilineage differentiation potential. POAT-MSCs exhibited enhanced chondrogenic differentiation compared to SAT-MSCs, with stronger extracellular matrix deposition and significantly increased COL2A1 expression at later stages of differentiation than SAT-MSCs. SOX9 expression supported a more advanced chondrogenic commitment in POAT-derived cells, while COL10A1 expression remained low and stable in both groups. These preliminary findings suggest that POAT, routinely discarded after ovariectomy, may represent a promising and ethically advantageous source of canine MSCs for regenerative medicine.