Abstract
The study of canine bone marrow-derived mesenchymal stem cells (MSC) has a prominent position in veterinary cell-based applications. Yet the plethora of breeds, their different life spans and inter-breed variations provide unclearness on what can be achieved specifically by such therapies. In this study, we compared a set of morphological, physiological, and genetic markers of MSC derived from large dog breeds, namely: Border collie, German shepherd, Labrador, Malinois, Golden retriever and Hovawart. We compared colony forming units (CFU) assay, population doubling time (PDT), senescence-associated β-galactosidase (SA-β-Gal) activity, telomere length and gene expression of MSC, as well as the ability of cells to differentiate to osteogenic, adipogenic and chondrogenic phenotypes. The influence of the culture media α-MEM, low glucose DMEM and high glucose DMEM, used in cell isolation and expansion, was investigated in presence and absence of basic Fibroblast Growth Factor (bFGF). Initial cell yield was not affected by culturing medium, but MSC expanded best in α-MEM supplemented with bFGF. After isolation, the number of MSC was similar among breeds - as shown by equivalent CFU - except in the Hovawart samples, which had fivefold less CFU. Telomere lengths was similar among breeds. MSC divided actively only for four weeks in culture (PDT = ~50 hours/division), except Border collie cells divided for longer time than cells from other groups. The percentage of senescent cells increased linearly in all breeds with time, with a faster rate in German shepherd, Labrador and Golden retriever. Border collie cells underwent efficient osteogenic differentiation, Hovawart cells performed the best in chondrogenic differentiation and Labrador cells in both, while German shepherd cells had the lower differentiation potential. MSC from all breed preserved the same adipogenic differentiation potential. In conclusion, despite variations, isolated MSC can be expanded and differentiated in vitro and all breeds are eligible for MSC-based therapies.
Bertolo, A