Adipose-derived mesenchymal stem cells (aMSC) have been steadily increasing as a viable alternative therapeutic modality in veterinary medicine. Besides direct regenerative properties, aMSC have the potential for therapeutic benefit via their ability to alter their surrounding cellular environment and thus modulate inflammatory response in conditions such as inflammatory bowel disease, feline asthma, arthritis, gingivostomatitis and chronic kidney disease.
Previous studies have shown functional deficits exhibited by MSC collected from aged and diseased human and rodent donors; in particular, decrease in proliferation potential, which is important for obtaining sufficient cells needed for therapy. Little is known regarding the effect of donor age, disease status or collection location on the proliferation potential, characterization and immunomodulatory potential of feline aMSC.
Dr. Quimby and collaborators at the College of Veterinary Medicine at Colorado State University in Fort Collins, Colorado compared the ability of feline aMSC derived from young and geriatric cats. Adipose tissues from 5 young cats (<1.5 years old) and 6 geriatric cats (10-19 years old) were harvested from the ventral abdomen for aMSC isolation and culture. The 5 young cats were healthy while 3 of the geriatric cats had chronic kidney disease and 3 had neoplasia. The aMSC were assessed for their ability to proliferate in culture, ability to modulate lymphocyte proliferation (i.e. immunomodulation), and senescence (i.e. viability).
Proliferation ability of geriatric cats was noted to take a longer time to reach first confluency or passage 2 (i.e. 70– 90% surface covered by adherent cells). The aMSC from geriatric cats took 11 days (range 9–22 days) compared with aMSC from young healthy cats that took 7 days (range 6–8 days). Once the cells were expanded, no statistically significant difference was detected in terms of their ability to suppress lymphocyte proliferation or senescence.
In conclusion, compared with young feline aMSC, geriatric aMSC are impaired in their ability to rapidly proliferate to passage two following initial culture, which presents a concern for autologous therapy; in other words, when the donor aMSC individual and recipient aMSC patient are the same individual. Nonetheless, once the cells are expanded, young and geriatric cat aMSC appear to be equivalent in terms of their ability to suppress T-cell activation and proliferation. [GO]