Notochordal cell rich nucleus pulposus tissue increases proteoglycan accumulation and promotes a healthy nucleus pulposus phenotype in human MSCs

pulposus phenotype in human MSCs +Purmessur, D; Godburn K; Abbott, RD: Schek RM; Iatridis JC +University of Vermont, Burlington VT Senior author [email protected] INTRODUCTION Mesenchymal stem cells (MSCs) are an attractive cell source for IVD repair, yet the means of differentiating these cells to a nucleus pulposus (NP) phenotype is not clear and an area of high priority. Notochordal cells (NCs) play an influential role in early development of the intervertebral disc (IVD). NCs populating the nucleus pulposus (NP) disappear during growth in humans, but certain species that do not experience IVD degeneration retain NCs into maturity . Conditioned media from NCs seeded in alginate stimulated significant proteoglycan biosynthesis of human MSCs after 7 days in culture suggesting NCs may promote MSC differentiation toward a young NP phenotype. However this study on NC conditioned media was of short duration, has not been replicated, and did not include soluble factors from notochordal cell rich NP tissues. The aim of this study was to compare effects of conditioned media derived from NCs both seeded in alginate and derived from notochordal NP tissue on MSC differentiation toward an NP phenotype in a 3 week study.