Isolation, expansion and characterisation of mesenchymal stem cells from osteoarthritic and osteoporotic donors

Osteoporosis and osteoarthritis are common diseases with significant rates of morbidity associated with same. The search continues for effective treatment strategies for both diseases. Mesenchymal stem cells (MSCs) are critical components in the effective formation and repair of healthy bone and cartilage. Understanding the characteristics and behaviour of MSC’s in osteoarthritic and osteoporotic patients can help delineate and characterise the pathogenesis of these diseases further. The first aim of this study involves the creation of a biobank of osteoporotic and osteoarthritic MSC’s. The second aim includes analysing differentiation potential and cell migration/homing capabilities of these diseased MSC’s. Continuing from these results, a third aim is to explore aspects of how diseased MSC’s may interfere with TGF-β1 signalling, given the potent role of this pathway in regulating bone and cartilage metabolism. Bone marrow aspirates were obtained from osteoarthritic, osteoporotic and healthy donors undergoing scheduled hip surgery in the University of Limerick hospital group. Bone marrow aspirates were extracted through the exposed acetabulum during arthroplasty surgery. MSCs were isolated through standard in vitro culture conditions and underwent characterisation and differentiation as per the criteria outlined by the International Society of Cellular Therapy guidelines. Osteoporotic and osteoarthritic MSCs were then analysed for their osteogenic and adipogenic differentiation potential, migratory capacity and interplay with aspects of TGF-β1 signalling. A total of 10 donors were included in the study with no difficulties or complications arising from obtaining bone marrow aspirates during necessary arthroplasty surgery. MSCs were characterised using flow cytometry and by demonstration of their capacity to differentiate along adipogenic, chondrogenic and osteogenic lineages. Osteoporotic MSCs had an increased propensity to differentiate along the adipogenic lineage in comparison to their osteoarthritic counterparts. Both osteoporotic and osteoarthritic MSCs had altered chemokinetic profiles in comparison to healthy controls. Of particular interest, whilst healthy MSCs migrate towards TGF-β1, osteoporotic MSCs failed to migrate towards this important chemoattractant. The results of this research detail the successful extraction and isolation of MSCs from patients with osteoarthritis and osteoporosis. The surgical location and technique incorporates a transferable skill that could result in largescale collection of both healthy and diseased MSCs. A critical finding includes the altered migration of MSCs towards TGF-β1. This has implications both in the basic understanding of the pathogenesis of osteoporosis and in the development of future therapeutic targets.