Isolation and biological characterization of tendon-derived stem cells from fetal bovine

The lack of appropriate candidates of cell sources for cell transplantation has hampered efforts to develop therapies for tendon injuries, such as tendon rupture, tendonitis, and tendinopathy. Tendon-derived stem cells (TDSCs) are a type of stem cells which may be used in the treatment of tendon injuries. In this study, TDSCs were isolated from 5-mo-old Luxi Yellow fetal bovine and cultured in vitro and further analyzed for their biological characteristics using immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) assays. It was found that primary TDSCs could be expanded for 42 passages in vitro maintaining proliferation. The expressions of stem cell marker nucleostemin and tenocyte-related markers, such as collagen I, collagen II, collagen III, and tenascin-C, were observed on different passage cells by immunofluorescence. The results from RT-PCR show that TDSCs were positive for collagen type I, CD44, tenascin-C, and collagen type III but negative for collagen type II. Meanwhile, TDSC passage 4 was successfully induced to differentiate into osteoblasts, adipocytes, and chondrocytes. Our results indicate that the fetal bovine TDSCs not only had strong self-renewal capacity but also possess the potential for multi-lineage differentiation. This study provides theoretical basis and experimental foundation for potential therapeutic application of the fetal bovine TDSCs in the treatment of tendon injuries.