Abstract
As we grow older, the risk of tendon degeneration and injuries increases, which can result in pain, disability, healthcare cost, and lost productivity. Even after surgical repair the results are often unsatisfactory. The cellular reasons for the differences in the healing potential, however, are not well studied. To get a deeper insight into the biological characteristics of tenocyte-like cells from different patient groups we established a biobank with material from over 150 human donors. The patients/donors suffered from rotator cuff tears and were operated to restore the function. A proportion of the isolated cells showed stem cell-like characteristics and was able to differentiate into the osteoblastic, chondrogenic and adipogenic linage. Investigating the differentiation potential of the cells with regard to donor characteristics, we were able to demonstrate that age, sex but also the “degeneration” has an impact of the cellular potential. A possibility to stimulate the cellular activity is the application of growth factors, as already clinically used for stimulation of bone healing. Therefore, the responsiveness of the cells to the growth factors Bone Morphogenetic protein-2/7 (BMP-2/7) was analysed in vitro. Independent of the donor characteristics, the cells responded to the BMP-stimulation by increased proliferation and collagen-1 synthesis. However, cells isolated from donors with high fatty infiltration of the muscle or older females were less responsive. Looking into the intracellular signalling pathway, the data showed that the BMP-signal is mainly mediated by the canonical-pathway with samd8 playing a major role. This basic research gives first information regarding the differences in tenocytes biology with respect to the donor and is important for the understanding of tendon regeneration and the future development of new treatment strategies.
