Potentiation of cryopreserved rat adipose-derived multipotent mesenchymal stromal cells by BMP-12 in vitro for the treatment of tendinopathy

Abstract

Bone morphogenetic proteins (BMP), which are part of TGF-b superfamily, have a stimulating effect on bone formation, as well as the proliferation of tenocytes and fibroblasts, which form the tendon tissue.The purpose of the study was to determine the effect of BMP-12 on the morphofunctional characteristics of cryopreserved rat adipose-derived multipotent mesenchymal stromal (AT-MMSCs) and to investigate the effects of the use of AT-MMSCs pre-cultured with BMP-12 on the tendinopathy model.Materials and methods. MMSCs were obtained from the adipose tissue of rats. Cryopreservation was carried out under the protection of 10 % DMSO with the addition of 20 % fetal bovine serum at a cooling rate of 1 °C/min to -80 °C and subsequent transfer to liquid nitrogen. When culturing AT-MMSCs, the BMP-12 was added at the concentration of 50 ng/mL. The ability of cells to proliferation (by MTT-test) and the synthesis of collagen I and III types were evaluated. Rats with modeled degenerative-dystrophic injury to the Achilles tendons were locally administered with 0.25·106 AT-MMSCs or AT-MMSCs+BMP-12 in the defect zone. The animals injected with saline provided control group. On the 21st day after the treatment, a histological, immunofluorescence and biomechanical studies were performed.Results. The application of BMP-12 results in the decrease in proliferation of AT-MMSCs along with an increase in the relative number of cells that synthesize collagen I and III types relative to AT-MMSCs cultivated under standard conditions. The injection of AT-MMSCs promotes the activation of regenerative processes in damaged tendons. The use of AT-MMSCs+BMP-12 accelerates the histological structure, strength, and the content of collagen I and III types in the Achilles tendons of animals with degenerative-dystrophic damage compared to the cells without BMP-12.Conclusions BMP-12 can be used as a stimulating agent for the tenogenic differentiation of AT-MMSCs before transplantation into the damaged tendon tissue