Human adipose-derived mesenchymal stem cells: direction to a phenotype sharing similarities with the disc, gene...

Biologic therapies for disc degeneration hold great promise as an emerging concept. Due to ease of harvest and abundance, adipose derived-mesenchymal stem cells (AD-MSC) are a readily available cell source for such therapies. Our objectives in this study were (1) to develop/validate methods to harvest AD-MSC and direct them to a disc-like phenotype by three-dimensional (3D) culture and transforming growth factor (TGF)-beta3 exposure, (2) to assess cell phenotypes with gene expression profiling for these human AD-MSC and annulus cells, and (3) to test whether disc cell-AD-MSC coculture could augment glycosaminoglycan (GAG) production. When AD-MSC were exposed to TGF-beta3, greater extracellular matrix was formed containing types I and II collagen, keratan sulfate, and decorin. Biochemical GAG measurement showed that production was significantly greater in TGF-beta3-treated AD-MSC in 3D culture versus untreated controls (p < 0.05). Gene expression patterns in AD-MSC were compared to annulus cells; 4424 genes were significantly upregulated, and 2290 genes downregulated. Coculture resulted in a 44% greater GAG content compared with AD-MSC or annulus culture alone (p = 0.04). Data indicated that human AD-MSC can successfully be manipulated in 3D culture to express gene products important in the disc, and that coculture of annulus cells with AD-MSC enhances total GAG production.