ABSTRACT
BACKGROUND: Human amniotic mesenchymal stem cells (hAMSCs) are adult stem cells with multipotential differentiation, which can be induced to differentiate into bone, cartilage and other connective tissues. Meanwhile, as a highly specific marker of tenocytes, Scleraxis is involved in aggregation and differentiation of tendon progenitor cells as well as the formation of tendon extracellular matrix. OBJECTIVE: To investigate whether hAMSCs have the ability of differentiation into tenocytes by ectopic expression of Scleraxis. METHODS: Agreed by puerpera, the amniotic membrane from the full-term placenta was separated, and hAMSCs were isolated by a two-step enzyme digestion, observed under inverted phase contrast microscope, and identified by flow cytometry. Passage 3 cells were induced via plasmid-mediated Scleraxis overexpression in overexpression group. Untransfected cells cultured in normal medium served as blank control group, and those with empty plasmid transfection were defined as empty plasmid group. Cell proliferation was tested in each group using cell counting kit-8 within 7 days of culture. Real-time quantitative PCR and western blot were used to assess the tenogenic differentiation of hAMSCs in each group at 3 and 7 days of culture. RESULTS AND CONCLUSION: Findings from the cell counting kit-8 indicated that the cell viability had no significant differences among the groups within 7 days of culture (P > 0.05). Western blot results showed the protein expression of Scleraxis in the treatment group was significantly higher than that in the other two groups (P < 0.05). Real-time PCR results showed, at 3 days of culture, the expression of collagen type I, collagen type III, Fibronectin and Tenascin-C in the overexpression group was significantly higher than that in the empty plasmid group (P < 0.05), but the expression of Tenomodulin had no difference (P > 0.05); at 7 days of culture, the expressions of collagen type I, collagen type III, Fibronectin, Tenascin-C and Tenomodulin in the overexpression group were significantly higher than those in the empty plasmid group (P < 0.05). In summary, hAMSCs can be differentiated into tenocytes by ectopic expression of Scleraxis.
ABSTRACT
BACKGROUND: Particulated juvenile cartilage allograft is simple and easy to obtain, and chondrocytes can migrate and proliferate as confirmed by in vitro culture.In the Unite States,this technique has been used in the repair of cartilage defects in the hip, knee, ankle, and elbow joints. OBJECTIVE: To review the present situation, application, and value of particulated juvenile cartilage allograft transplantation for articular cartilage repair. METHODS: A computer-based search of CNKI, PubMed, and Elsevier was performed for retrieving articles concerning particulated juvenile cartilage allograft transplantation for articular cartilage repair published from October 1983 to June 2017. The keywords were "allogeneic juvenile cartilage particles; cartilage tissue engineering; articular cartilage defects;repair" in Chinese and English, respectively. After initial screening of titles and abstracts and exclusion of irrelevant articles, 48 eligible articles were included in final analysis. RESULTS AND CONCLUSION: (1) Although a variety of treatments for cartilage repair have achieved good clinical outcomes in short-term follow-up, improving the motor function of patients and relieving pain, patients eventually develop progressive degeneration of the articular cartilage and suffer from osteoarthritis. (2) Chondrocytes from allogeneic juvenile cartilage particles have stronger ability of proliferating and repairing cartilage defects in vitro than mature chondrocytes,and have low antigenicity,which cannot cause a strong rejection after in vivo transplantation.What's more, particulated juvenile cartilage allograft transplantation can be performed as one-stage surgery if cartilage defects are confirmed under arthroscopy. (3) Particulated juvenile cartilage allograft transplantation has achieved good outcomes in basic and clinical studies in the United States. Its potential superiority has gradually been accepted by doctors and patients. (4) There are also risks for being contaminated and spreading diseases during the preparation of particulated juvenile cartilage allograft. This technology has been widely used in the United States, but there are rare data concerning its follow-up studies. Therefore, an investigation on its long-term follow-up is indispensable for the objective assessment of its long-term efficacy, with a view to the extensive promotion of this technology in the clinical practice.