The effect of Link N on differentiation of human bone marrow-derived mesenchymal stem cells
1 Division of Orthopaedic Surgery, McGill University, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada
2 Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, 3755 Chemin de la Cote Ste-Catherine, Montreal, QC, H3T 1E2, Canada
3 Orthopaedic Research Laboratory, Royal Victoria Hospital, McGill University, 687 Pine Avenue West Montreal, QC, H3A 1A1, Canada
4 Genetics Unit, Shriners Hospitals for Children, 1529 Cedar Avenue, Montreal, QC, H3G 1A6, Canada
Arthritis Research & Therapy 2012, 14:R267 doi:10.1186/ar4113Published: 10 December 2012
We previously showed that Link N can stimulate extracellular matrix biosynthesis by intervertebral disc (IVD) cells, both in vitro and in vivo, and is therefore a potential stimulator of IVD repair. The purpose of the present study was to determine how Link N may influence human mesenchymal stem cell (MSC) differentiation, as a prelude to using Link N and MSC supplementation in unison for optimal repair of the degenerated disc.
MSCs isolated from the bone marrow of three osteoarthritis patients were cultured in chondrogenic or osteogenic differentiation medium without or with Link N for 21 days. Chondrogenic differentiation was monitored by proteoglycan staining and quantitation by using Alcian blue, and osteogenic differentiation was monitored by mineral staining and quantitation by using Alzarin red S. In addition, proteoglycan secretion was monitored with the sulfated glycosaminoglycan (GAG) content of the culture medium, and changes in gene expression were analyzed with real-time reverse transcription (RT) PCR.
Link N alone did not promote MSC chondrogenesis. However, after MSCs were supplemented with Link N in chondrogenic differentiation medium, the quantity of GAG secreted into the culture medium, as well as aggrecan, COL2A1, and SOX9 gene expression, increased significantly. The gene expression of COL10A1 and osteocalcin (OC) were downregulated significantly. When MSCs were cultured in osteogenic differentiation medium, Link N supplementation led to a significant decrease in mineral deposition, and alkaline phosphatase (ALP), OC, and RUNX2 gene expression.
Link N can enhance chondrogenic differentiation and downregulate hypertrophic and osteogenic differentiation of human MSCs. Therefore, in principle, Link N could be used to optimize MSC-mediated repair of the degenerated disc.