The Influence of Culture Medium Type on Cellular Phenotype of Canine Adipose Derived Stem Cells

Canine adipose derived stem cells (ASCs) hold a great promise for the therapy of osteoarthritis in veterinary medicine. Current therapy is an autologous, stromal vascular fraction. Allogeneic ASCs provide many advantages, including efficient, cost-effective treatments while eliminating a surgical procedure in a diseased animal. Cultured ASCs can be expanded and characterized, allowing selection of desirable qualities. Use of allogeneic ASCs requires selection of a culture medium that provides consistent, desirable cellular products. The supplements within a medium can greatly influence cellular phenotypes. We hypothesized that medium type influenced cellular phenotype, allowing selection of a specified cellular product for clinical applications. We evaluated ASCs derived from adipose tissue of six dogs, assessing mRNA expression of proinflammatory: interleukin-1b, cyclooxygenase-2, and anti-inflammatory mediators: tissue inhibitor metalloproteinase-2 and interleukin -1 receptor antagonist, via quantitative RT-PCR prior to, and following culture in five cell culture media: basic cell growth medium (BGM), Keratinocyte N acetyl-L-cysteine supplemented (KNAC) medium, Multipotent Adult Progenitor Cell (MAPC) medium, serum free medium (SFM) and xeno-free medium. Major histocompatability complex I (MHCI), major histocompatability complex II (MHCII), CD44 and CD90 immunophenotypes were assessed via flow cytometry analysis. Tri-lineage differentiation (bone, adipose and cartilage tissue) was utilized to verify multipotency. SFM and xeno-free culture conditions did not produce cell expansion sufficient to assess phenotype. ASCs prior to culture had wide variability in all mediator levels, while culturing in the remaining conditions resulted in more predictable expression levels of inflammatory mediators, with a decrease in all levels. Cultured ASCs retained expression of cell surface markers MHCI, CD44 and CD90, while decreasing MHCII expression levels. KNAC and MAPC medium conditions consistently produced tri-lineage differentation; BGM, SFM and xeno-free medium did not. Culture condition will influence phenotype of ASCs, and should be selected according to the intended therapeutic effect.