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Zhang N.,Shanghai JiaoTong University | Liu H.-Q.,Shanxi University | Zhao X.-Y.,Shanghai JiaoTong University | Tong W.-X.,Shanghai JiaoTong University | And 2 more authors.
Journal of Shanghai Jiaotong University (Medical Science) | Year: 2014

Objective: To investigate the effects of TNF receptor associated factor 3 (TRAF3) on signaling pathways and expressions of downstream products of MAPK and NF-κB in chondrocytes stimulated by the interleukin-17 (IL-17); to observe the cartilage destruction of TRAF3 transgenic mice stimulated by the IL-17; and to explore the protective effect of TRAF3 on the cartilage.Methods: Changes of signaling pathways of NF-κB and MAPK in normal chondrocytes and TRAF3 transgenic chondrocytes stimulated by the IL-17 were detected by the Western blotting. The changes of mRNA of downstream inflammatory factor IL-6, metabolic factors MMP13, disintegrin and metalloproteinase with thrombospondin motif 4 (ADAMTS-4), and ADAMTS-5 in normal chondrocytes and TRAF3 transgenic chondrocytes stimulated by the IL-17 were detected by the Real-Time PCR. Differences of cartilage changes of wildtype mice and TRAF3 transgenic mice stimulated by the IL-17 were observed by the histochemistry.Results: The over-expression of TRAF3 significantly inhibited the signaling pathways of MAPK and NF-κB in chondrocytes stimulated by the IL-17 and significantly down-regulated the expression of mRNA of downstream inflammatory factors IL-6, MMP13, ADAMTS-4, and ADAMTS. The cartilage breakdown of TRAF3 transgenic mice induced by the IL-17 was significantly less than that of wildtype mice.Conclusion: TRAF3 is a negative regulatory inhibitor of the signaling pathways of IL-17 and may be a new target of inhibiting the cartilage breakdown. Source

Yue B.,Harvard University | Yue B.,Shanghai Key Laboratory of Orthopaedic Implant | Varadarajan K.M.,Harvard University | Rubash H.E.,Harvard University | Li G.,Harvard University
International Orthopaedics | Year: 2012

Purpose: The object of this study was to investigate the in vivo function of the posterior cruciate ligament (PCL) in patients before and after a PCL-retaining total knee arthroplasty (TKA). Methods: Eleven patients with advanced osteoarthritis (OA) of the knee were recruited. Magnetic resonance scans of each OA knee were obtained, and 3D computer models, including the femoral and tibial insertion areas of the anterolateral and posteromedial bundles of the PCL, were created. Before and after PCL-retaining TKA, dual fluoroscopic images of each knee were acquired during weight-bearing knee flexion. The images and computer models were used to reproduce the in vivo motion of the knee. The function of the PCL bundles was described in terms of elongation, elevation and deviation. Twenty-two healthy controls were also included as normal references. Results: PCL bundles of the OA knees were overstretched during late knee flexion and orientated more medially throughout flexion compared with normal knees. After PCL-retaining TKA, PCL bundles were further overstretched during late flexion and changed from medially directed in normal and OA knees to almost sagittally directed, which may compromise function in controlling knee rotation. Conclusions: The current PCL-retaining TKA systems and surgical techniques may not adequately re-establish normal biomechanics of PCL bundles after PCL-retaining TKA. © Springer-Verlag 2012. Source

Liu S.,Shanghai JiaoTong University | Fan C.,Shanghai JiaoTong University | Jin F.,Shanghai JiaoTong University | Zhao L.,Shanghai Key Laboratory of Orthopaedic Implant | And 2 more authors.
International Journal of Applied Ceramic Technology | Year: 2015

Infection is still a major concern in bone implants, especially in the implants with porous structures. As silver shows superior and broad-spectrum antibacterial activity, porous silver-doped β-tricalcium phosphate (β-TCP) bioceramics are prepared with 5% and 10% nanometer silver. The bioceramics show similar porous macrostructure with pure β-TCP bioceramic, except slightly color change. They have almost identical microstructure to its pure β-TCP counterpart under field emission scanning electron microscope. Their physical, chemical, and mechanical properties were investigated with X-ray diffraction, Fourier transforming infrared spectrometer, and AG-5kN, and no significant difference has been found between silver-doped β-TCP bioceramics and pure β-TCP bioceramic. Bactericidal concentration of silver ions was detected in the solution soaked with the bioceramics. They can efficiently inhibit the growth of Staphylococcus epidermidis and Styphylococcus aureus, but show no cytotoxicity to L929 cells. It suggests that silver-doped β-TCP bioceramics can be developed into new type of bone substitutes with anti-infection properties. © 2013 The American Ceramic Society. Source

Peng Z.-X.,Shanghai Key Laboratory of Orthopaedic Implant | Wang L.,Shanghai JiaoTong University | Du L.,Shanghai Key Laboratory of Orthopaedic Implant | Guo S.-R.,Shanghai JiaoTong University | And 2 more authors.
Carbohydrate Polymers | Year: 2010

Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was synthesised with differing degrees of substitution (6%, 18% and 44%) of quaternary ammonium by reacting chitosan with glycidyl trimethylammonium chloride. The antibacterial activities of these polymers were tested in vitro against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, and Staphylococcus epidermidis. Mouse fibroblasts and bone marrow derived stromal cells (hMSCs) were used to investigate the biocompatibility of the HACC. The results show that the antibacterial activities of the HACC with 18% or 44% substitution were significantly higher than the others (P < 0.05) against all three bacteria. HACC with 6% or 18% substitution was not cytotoxic and did not interfere with the proliferation and osteogenic differentiation of hMSCs. Overall, we can make a conclusion that HACC with an 18% substitution was a potential pharmaceutical that can inhibit the growth of bacteria and has good biocompatibility with osteogenic cells. © 2010 Elsevier Ltd. All rights reserved. Source

Zuo C.,Shanghai JiaoTong University | Huang Y.,Shanghai Key Laboratory of Orthopaedic Implant | Bajis R.,University of Western Australia | Sahih M.,University of Western Australia | And 5 more authors.
Osteoporosis International | Year: 2012

Bone remodeling is essential for adult bone homeostasis. The failure of this process often leads to the development of osteoporosis, a present major global health concern. The most important factor that affects normal bone remodeling is the tightly controlled and orchestrated regulation of osteoblasts and osteoclasts. The present review summarized the recent discoveries related to osteoblast regulation from several signals, including transforming growth factor-β, bone morphogenetic proteins, Wnt signal, Notch, Eph-Ephrin interaction, parathyroid hormone/parathyroid hormone-related peptide, and the leptin-serotonin-sympathetic nervous systemic pathway. The awareness of these mechanisms will facilitate further research that explores bone remodeling and osteoporosis. Future investigations on the endogenous regulation of osteoblastogenesis will increase the current knowledge required for the development of potential drug targets in the treatment of osteoporosis. © International Osteoporosis Foundation and National Osteoporosis Foundation 2012. Source

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