Comparative Analysis of Platelet-rich Plasma Effect on Tenocytes from Normal Human Rotator Cuff Tendon and Human Rotator Cuff Tendon with Degenerative Tears

BACKGROUND: Platelet-rich plasma (PRP) stimulates cell proliferation and enhances matrix gene expression and synthesis. However, there have been no comparative study of the PRP effect on the normal and degenerative tenocytes. The purpose of this study was to compare the effect of PRP on tenocytes from normal and degenerative tendon. METHODS: Tendon tissues were obtained from patients undergoing arthroscopic repair (n=9) and from healthy donors (n=3). Tenocytes were cultured with 10% (vol/vol) platelet-poor plasma, PRP activated with calcium, and PRP activated with calcium and thrombin. The total cell number was assessed at days 7 and 14. The expressions of type I and III collagen, decorin, tenascin-C, and scleraxis were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction. The total collagen and glycosaminoglycan (GAG) synthesis was evaluated at days 7 and 14. RESULTS: No differences were observed between the groups at day 7, but cell proliferation was remarkably increased in tenocytes from the degenerative tendon at day 14. In both tenocyte groups, the gene expressions of type I and III collagen were up-regulated. GAG synthesis was greater in the normal tendon, whereas the expressions of decorin and tenascin-C were increased in tenocytes from the degenerative tendon. Tenocytes from the degenerative tendon had higher fold-change of GAG synthesis and a lower collagen III/I ratio than normal tenocytes. CONCLUSIONS: PRP promoted the cell proliferation and enhanced the synthesis of tendon matrix in both groups. PRP has a greater positive effect on cell proliferation, matrix gene expression and synthesis in tenocytes from degenerative tendon.

Mesenchymal stromal cells from bone marrow treated with bovine tendon extract acquire the phenotype of mature tenocytes / Células mesenquimais do estroma da medula óssea tratadas com extrato de tendão bovino adquirem o fenótipo de tenócitos maduros

This study evaluated in vitro differentiation of mesenchymal stromal cells isolated from bone marrow, in tenocytes after treatment with bovine tendon extract. METHODS: Bovine tendons were used for preparation of the extract and were stored at -80 °C. Mesenchymal stromal cells from the bone marrow of three donors were used for cytotoxicity tests by means of MTT and cell differentiation by means of qPCR. RESULTS: The data showed that mesenchymal stromal cells from bone marrow treated for up to 21 days in the presence of bovine tendon extract diluted at diminishing concentrations (1:10, 1:50 and 1:250) promoted activation of biglycan, collagen type I and fibromodulin expression. CONCLUSION: Our results show that bovine tendon extract is capable of promoting differentiation of bone marrow stromal cells in tenocytes.

O estudo avalia a diferenciação in vitro das células mesenquimais isoladas do estroma da medula óssea em tenócitos após tratamento com extrato de tendão bovino. MÉTODOS: Tendões bovinos foram usados para confecção do extrato e estocados a -80 °C. Células mesenquimais do estroma da medula óssea (BMSCs) de três doadores foram usadas para os testes de citotoxicidade por MTT e diferenciação celular por qPCR. RESULTADOS: Os dados mostram que células mesenquimais do estroma da medula óssea tratadas por até 21 dias em presença do extrato de tendão bovino diluído em concentrações crescentes (1:10, 1:50 e 1:250) promovem a ativação da expressão de biglican, colágeno tipo I e fibromodulina. CONCLUSÃO: Nossos resultados mostram que o extrato de tendão bovino é capaz de promover a diferenciação das BMSCs em tenócitos.

Construction of Eukaryotic Expression Plasmid of bFGF Gene in Rats and Its Expression in Tenocytes / 华中科技大学学报（医学）（英德文版）

The bFGF plays an important role in embryonic development of tendons and ligaments and in the healing of injuried tendons and ligaments. The eukaryotic expression plasmid of rat basic fibroblast growth factor (bFGF) gene was constructed in order to further investigate the bFGF function in molecular regulatory mechanism in the repair of tendons and ligaments and to provide the foundation for the clinical application. The cDNA fragments of bFGF were cloned from the skin of rats by RT-PCR, and recombinated to the pMD18-T vector. The cDNA encoding bFGF was cloned from the pMD18-T vector by RT-PCR, digested with restriction enzyme EcoR Ⅰ, Pst Ⅰ and bound to eukaryotic expression plasmid pIRES2-EGFP to construct eukaryotic expression plasmid pIRES2-EGFP-bFGF. The pIRES2-EGFP-bFGF was transfected into the tenocytes by lipid-mediated ransfection technique. MTT test was used to detect the biological activity of bFGF in supematants after the transfection. The expression of type Ⅰ and Ⅲ collagen genes was detected by using RT-PCR. It was verified that the pIRES2-EGFP-bFGF was successfully constructed, and its transfection into tenocytes could significantly enhance the biological activity of bFGF, and increase the expression of type Ⅰ and Ⅲ collagen mRNA, suggesting that pIRES2-EGFP-mediated bFGF gene therapy was beneficial to the repair of tendons and ligaments.

The committed differentiation of bone marrow mesenchymal stem cells into tenocytes / 解放军医学杂志

Objective To investigate the feasibility of committed differentiation of rhesus bone marrow mesenchymal stem cells (MSCs) into tenocytes induced by BMP12. Methods MSCs were transfected with pTARGETTM bearing BMP12 gene by electroporation. The transfected cells were identified by morphological observation and molecular biological measure. Results Under the observation of light microscope, the morphological features of transfected cells changed significantly compared to parental MSCs. RT-PCR data showed the transfected cells had the mRNA expression of BMP12 and collagen Ⅰ, but without that of collagen Ⅲ. 98.39% of the transfected cells were CD44+ and negative for HLA-DR. Conclusion BMP12 could induce MSCs into tenocytes, and bone marrow MSCs might be the optional seed cells for tendon tissue engineering.

Gene expression and tenocyte proliferation of nuclear factor-?B under the stimulation of basic fibroblast growth factor / 中华创伤杂志

Objective To investigate the effect of nuclear factor-?B (NF-?B), NF-?B-inducing kinase (NIK) and I-?B in basic fibroblast growth factor (bFGF) promoting gene expression and signal transduction of tenocyte NF-?B. Methods Tenocytes isolated from rabbits were divided into 3 groups with 8 dishes: no bFGF (Group A), 2 ng/ml bFGF (Group B) and 10 ng/ml bFGF (Group C). Cells in all dishes were cultured for 5 days. The effect of bFGF on tenocytes proliferation was examined by means of growth curve analysis. The mRNA was isolated after 5 days and the gene expressions of NIK,IKK? and IKK? induced by NF-?B investigated by reverse transcription-polymerase chain reaction (RT-PCR). Results The growth curve moved forward with the dosage increase of bFGF. Gene expressions of NF-?B,NIK, I?B kinase (IKK)? and IKK? were 0.4? 0.2 , 0.4 ? 0.1 , 0.3 ?0.1 and 0.2?0.1 respectively in the Group B and 1.8?0.5,1.0?0.3, 0.8 ? 0.2 and 1.5 ? 0.4 in the Group C. Gene expressions were all up-regulated in the Groups B and C posterior to adding of bFGF. Conclusions bFGF stimulates tenocyte proliferation and up-regulates gene expression of NF-?B,NIK,IKK? and IKK?, as indicates that the signal transduction of promoting tenocyte proliferation by bFGF may be through NF-?B pathway.