Synovial mesenchymal stem cells accelerate early remodeling of tendon-bone healing
Tendon-bone healing is important for the successful reconstruction of the anterior cruciate ligament by using the hamstring tendon. Mesenchymal stem cells (MSCs) have attracted much interest because of their self-renewing potential and multipotentiality for possible clinical use. We previously reported that MSCs derived from synovium had a higher proliferation and differentiation potential than the other MSCs that we examined. The purpose of this study was to investigate the effect and mechanism of the implantation of the synovial MSCs on tendon-bone healing in rats. Half of the Achilles’ tendon grafts of rats were inserted into a bone tunnel from the tibial plateau to the tibial tuberosity with a suture-post fixation. The bone tunnel was filled with MSCs labeled with fluorescent marker DiI or without MSCs as the control. The tendon-bone interface was analyzed histologically, and collagen fibers were quantified. At 1 week, the tendon-bone interface was filled with abundant DiI-positive cells, and the proportion of collagen fiber area was significantly higher in the MSC group than in the control group. By 2 weeks, the proportion of oblique collagen fibers, which appeared to be Sharpey’s fibers, was significantly higher in the MSC group than in the control group. At 4 weeks, the interface tissue disappeared, and the implanted tendon appeared to attach to the bone directly in both groups. DiI-labeled cells could no longer be observed. Implantation of synovial MSCs into bone tunnel thus accelerated early remodeling of tendon-bone healing, as shown histologically.
KeywordsMesenchymal stem cells Tendon-bone healing Anterior cruciate ligament reconstruction Cell therapy Synovium Rat (Sprague Dawley)
We thank Kenichi Shinomiya, MD, PhD, for continuous support and Miyoko Ojima for expert help with histology. Recombinant human BMP2 was kindly provided by Astellas Pharma.
- Mochizuki T, Muneta T, Sakaguchi Y, Nimura A, Yokoyama A, Koga H, Sekiya I (2006) Higher chondrogenic potential of fibrous synovium- and adipose synovium-derived cells compared with subcutaneous fat-derived cells: distinguishing properties of mesenchymal stem cells in humans. Arthritis Rheum 54:843–853PubMedCrossRefGoogle Scholar
- Tolar J, O’Shaughnessy MJ, Panoskaltsis-Mortari A, McElmurry RT, Bell S, Riddle M, McIvor RS, Yant SR, Kay MA, Krause D, Verfaillie CM, Blazar BR (2006) Host factors that impact the biodistribution and persistence of multipotent adult progenitor cells. Blood 107:4182–4188PubMedCrossRefGoogle Scholar