Academy of Orthopedics

Guangzhou, China

Academy of Orthopedics

Guangzhou, China
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Zhu Z.,University of Tasmania | Laslett L.L.,University of Tasmania | Jin X.,University of Tasmania | Han W.,University of Tasmania | And 11 more authors.
Osteoarthritis and Cartilage | Year: 2017

Objective: To describe cross-sectional and longitudinal associations between magnetic resonance imaging (MRI)-detected osteophytes (OPs) and knee structural abnormalities and knee pain in older adults. Method: A prospective population-based cohort study of 895 participants aged 50-80 years (mean age 62 years, 50% female) was performed. T1-or T2-weighted fat suppressed MRI was used to assess knee OPs, cartilage volume, cartilage defects and bone marrow lesions (BMLs) at baseline and after 2.6 years. Radiographically-detected OPs were scored according to the Osteoarthritis Research Society International (OARSI) atlas. Knee pain was assessed using a self-administered questionnaire at baseline, 2.6 and 5 years later. Results: 85% of participants had MRI-detected OPs at baseline, while 10% of participants had radiographically-detected OPs. Cross-sectionally, higher gardes of MRI-detected OPs in all compartments were significantly, independently and site-specifically associated with higher prevalences of cartilage defects and BMLs, lower cartilage volume and higher prevalence of knee pain. Longitudinally, higher gardes of baseline MRI-detected OPs site-specifically predicted greater risks of any increase in cartilage defects or BMLs, and loss of cartilage volume in medial and lateral tibiofemoral (LTF) and total compartments over 2.6 years in multivariable analyses. These significant associations were similar in those without radiographically-detected OPs. MTF and total OP scores were significantly associated with change in total knee pain over 2.6 and 5 years but these became non-significant after adjustment for cartilage defects and BMLs. Conclusion: MRI-detected knee OPs are common and appear to be clinically relevant to knee structural changes in older adults. © 2017 Osteoarthritis Research Society International.

Wang X.,Southern Medical University | Pan M.,Southern Medical University | Wen J.,Southern Medical University | Tang Y.,Xiangnan University | And 9 more authors.
Neural Regeneration Research | Year: 2014

In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold (SAPNS)-containing poly(lactic-co-glycolic acid) (PLGA) conduit (SPC) and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury. © 2014, Editorial Board of Neural Regeneration Research. All rights reserved.

Wen J.,Southern Medical University | Qian C.,Southern Medical University | Pan M.,Southern Medical University | Wang X.,Southern Medical University | And 10 more authors.
Molecular Neurobiology | Year: 2017

RhoA, a member of Rho GTPases family, is known to play an important role in remodeling actin cytoskeleton. During the development of the peripheral nervous system (PNS), Schwann cells undergo proliferation, migration, and radial sorting and finally wrap the related axons compactly to form myelin sheath. All these processes involve actin cytoskeletal remodeling. However, the role of RhoA on Schwann cell during development is still unclear. To address this question, we first used a lentiviral vector-mediated short hairpin (sh) RNA targeting RhoA to knock down the expression of RhoA in the cultured Schwann cells in vitro. Effects of RhoA on Schwann cell proliferation and migration were examined by BrdU assay and transwell assay, respectively. Results of the present study indicated that downregulated RhoA expression in cultured Schwann cells significantly slacked the cells’ capabilities of migration and proliferation. Then, we investigated the role of RhoA in the developing rat sciatic nerves. Immunohistology and Western blotting showed that RhoA was mainly expressed in Schwann cells in the sciatic nerves and was peaked at 2 weeks postnatal then kept in low level up to 8 weeks. In the subjected rats whose sciatic nerves were microinjected with lentiviral vectors at postnatal 3 days, we found that the lentiviruses mainly transfected Schwann cells, and the RhoA expression in the transfected Schwann cells was significantly knocked down. Four weeks after lentivirus microinjection, immunohistology and transmission electron microscopy illustrated that RhoA knockdown resulted in hypomyelination and significant decrease of the thickness of myelin in the transfected area. Overall data of current study suggested that RhoA plays a critical role in Schwann cell biology and is essential for myelination in developing peripheral nerve. © 2016, Springer Science+Business Media New York.

Pan M.,Southern Medical University | Wang X.,Southern Medical University | Chen Y.,Southern Medical University | Cao S.,Chinese Academy of Sciences | And 13 more authors.
Experimental Neurology | Year: 2017

Peripheral nerve injury repair can be enhanced by Schwann cell (SC) transplantation, but clinical applications are limited by the lack of a cell source. Thus, alternative systems for generating SCs are desired. Herein, we found the peripheral blood-derived mesenchymal stem cells (PBMSCs) could be induced into SC like cells with expressing SC-specific markers (S100, P75NTR and CNPase) and functional factors (NGF, NT-3, c-Fos, and Krox20). When the induced PBMSCs (iPBMSCs) were transplanted into crushed rat sciatic nerves, they functioned as SCs by wrapping the injured axons and expressing myelin specific marker of MBP. Furthermore, iPBMSCs seeded in an artificial nerve conduit to bridge a 10-mm defect in a sciatic nerve achieved significant nerve regeneration outcomes, including axonal regeneration and remyelination, nerve conduction recovery, and restoration of motor function, and attenuated myoatrophy and neuromuscular junction degeneration in the target muscle. Overall, the data from this study indicated that PBMSCs can transdifferentiate towards SC-like cells and have potential as grafting cells for nerve tissue engineering. © 2017

Guo J.-S.,Southern Medical University | Guo J.-S.,Academy of Orthopedics | Qian C.-H.,Southern Medical University | Ling E.-A.,National University of Singapore | Zeng Y.-S.,Sun Yat Sen University
Current Medicinal Chemistry | Year: 2014

Spinal cord injury (SCI) is a common neurologic disorder that results in loss of sensory function and mobility. It is well documented that tissue engineering is a potential therapeutic strategy for treatment of SCI. In this connection, various biomaterials have been explored to meet the needs of SCI tissue engineering and these include natural materials, synthetic biodegradable polymers and synthetic non-degradable polymers. Nanofiber scaffolds are newly emerging biomaterials that have been widely utilized in tissue engineering recently. In comparison to the traditional biomaterials, nanofibers have advantages in topography and porosity, thus mimicking the naturally occurring extracellular matrix. Besides, they exhibit excellent biocompatibility with low immunogenicity, and furthermore they are endowed with properties that help to bridge the lesion cavity or gap, and serve as an effective delivery system for graft cells or therapeutic drugs. This review summarizes some of the unique properties of nanofiber scaffolds which are critical to their potential application in treatment of injured spinal cord. © 2014 Bentham Science Publishers.

Huang M.-J.,Southern Medical University | Huang M.-J.,Academy of Orthopedics | Wang L.,Southern Medical University | Wang L.,Academy of Orthopedics | And 22 more authors.
Annals of the Rheumatic Diseases | Year: 2014

Background: An exogenous supplement of n-3 polyunsaturated fatty acids (PUFAs) has been reported to prevent osteoarthritis (OA) through undefined mechanisms. Objective: This study investigated the effect of alterations in the composition of endogenous PUFAs on OA, and associations of PUFAs with mammalian target of rapamycin complex 1 (mTORC1) signalling, a critical autophagy pathway in fat-1 transgenic (TG) mice. Methods: fat-1 TG and wild-type mice were used to create an OA model by resecting the medial meniscus. The composition of the endogenous PUFAs in mouse tissues was analysed by gas chromatography, and the incidence of OA was evaluated by micro-computed tomography (micro-CT), scanning electron microscopy and histological methods. Additionally, primary chondrocytes were isolated and cultured. The effect of exogenous and endogenous PUFAs on mTORC1 activity and autophagy in chondrocytes was assessed. Results: The composition of endogenous PUFAs of TG mice was optimised both by increased n-3 PUFAs and decreased n-6 PUFAs, which significantly alleviated the articular cartilage destruction and osteophytosis in the OA model (p<0.01), decreased protein expression of matrix metalloproteinase-13 (MMP-13) and ADAMTS-5 (a disintegrin and metalloproteinase with thrombospondin motifs) in the articular cartilage (p<0.01) and reduced chondrocyte number and loss of cartilage extracellular matrix. Both exogenous and endogenous n-3 PUFAs downregulated mTORC1 activity and promoted autophagy in articular chondrocytes. Conversely, mTORC1 pathway activation suppressed autophagy in articular chondrocytes. Conclusions: Enhancement of the synthesis of endogenous n-3 PUFAs from n-6 PUFAs can delay the incidence of OA, probably through inhibition of mTORC1, promotion of autophagy and cell survival in cartilage chondrocytes. Future investigation into the role of the endogenous n-6/n-3 PUFAs composition in OA prevention and treatment is warranted.

Guo Y.,Academy of Orthopedics | Guo Y.,Southern Medical University | Tran R.T.,Pennsylvania State University | Xie D.,Academy of Orthopedics | And 13 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2015

Attempts to replicate native tissue architecture have led to the design of biomimetic scaffolds focused on improving functionality. In this study, biomimetic citrate-based poly (octanediol citrate)-click-hydroxyapatite (POC-Click-HA) scaffolds were developed to simultaneously replicate the compositional and architectural properties of native bone tissue while providing immediate structural support for large segmental defects following implantation. Biphasic scaffolds were fabricated with 70% internal phase porosity and various external phase porosities (between 5 and 50%) to mimic the bimodal distribution of cancellous and cortical bone, respectively. Biphasic POC-Click-HA scaffolds displayed compressive strengths up to 37.45 ± 3.83 MPa, which could be controlled through the external phase porosity. The biphasic scaffolds were also evaluated in vivo for the repair of 10-mm long segmental radial defects in rabbits and compared to scaffolds of uniform porosity as well as autologous bone grafts after 5, 10, and 15 weeks of implantation. The results showed that all POC-Click-HA scaffolds exhibited good biocompatibility and extensive osteointegration with host bone tissue. Biphasic scaffolds significantly enhanced new bone formation with higher bone densities in the initial stages after implantation. Biomechanical and histomorphometric analysis supported a similar outcome with biphasic scaffolds providing increased compression strength, interfacial bone ingrowth, and periosteal remodeling in early time points, but were comparable to all experimental groups after 15 weeks. These results confirm the ability of biphasic scaffold architectures to restore bone tissue and physiological functions in the early stages of recovery, and the potential of citrate-based biomaterials in orthopedic applications. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 772-781, 2015. © 2014 Wiley Periodicals, Inc.

Jie H.,Southern Medical University | Jie H.,Academy of Orthopedics | He Y.,Southern Medical University | He Y.,Academy of Orthopedics | And 13 more authors.
Oncotarget | Year: 2016

Neutrophils play a central role in innate immunity and are rapidly recruited to sites of infection and injury. Neutrophil apoptosis is essential for the successful resolution of inflammation. Necrostatin-1 (Nec-1,methyl-thiohydantoin-tryptophan (MTH-Trp)), is a potent and specific inhibitor of necroptosis[1] (a newly identified type of cell death representing a form of programmed necrosis or regulated non apoptotic cell death) by inhibiting the receptor interacting protein 1(RIP1) kinase. Here we report that Nec-1 specifically induces caspase-dependent neutrophils apoptosis and overrides powerful anti-apoptosis signaling from survival factors such as GM-CSF and LPS. We showed that Nec-1 markedly enhanced the resolution of established neutrophil-dependent inflammation in LPS-induced acute lung injury in mice. We also provided evidence that Nec-1 promoted apoptosis by reducing the expression of the anti-apoptotic protein Mcl-1 and increasing the expression of pro-apoptotic protein Bax. Thus, Nec-1 is not only an inhibitor of necroptosis, but also a promoter of apoptosis, of neutrophils, enhancing the resolution of established inflammation by inducing apoptosis of inflammatory cells. Our results suggest that Nec-1 may have potential roles for the treatment of diseases with increased or persistent inflammatory responses.

Ma Z.-P.,Southern Medical University | Ma Z.-P.,Academy of Orthopedics | Ma Z.-P.,Inner Mongolia University | Liao J.-C.,Southern Medical University | And 5 more authors.
Cell and Tissue Research | Year: 2015

Osteoporosis (OP) often increases the risk of bone fracture and other complications and is a major clinical problem. Previous studies have found that high blood pressure is associated with bone formation abnormalities, resulting in increased calcium loss. We have investigated the effect of the antihypertensive drug benidipine on bone marrow stromal cell (BMSC) differentiation into osteoblasts and bone formation under osteoporotic conditions. We used a combination of in vitro and in vivo approaches to test the hypothesis that benidipine promotes murine BMSC differentiation into osteoblasts. Alkaline phosphatase (ALP), osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), β-catenin, and low-density lipoprotein receptor-related protein 5 (LRP5) protein expression was evaluated in primary femoral BMSCs from C57/BL6 mice cultured under osteogenic conditions for 2 weeks to examine the effects of benidipine. An ovariectomized (OVX) mouse model was used to investigate the effect of benidipine treatment for 3 months in vivo. We found that ALP, OCN, and RUNX2 expression was up-regulated and WNT/β-catenin signaling was enhanced in vitro and in vivo. In OVX mice that were intragastrically administered benidipine, bone parameters (trabecular thickness, bone mineral density, and trabecular number) in the distal femoral metaphysis were significantly increased compared with control OVX mice. Consistently, benidipine promoted BMSC differentiation into osteoblasts and protected against bone loss in OVX mice. Therefore, benidipine might be a suitable candidate for the treatment of patients with postmenopausal osteoporosis and hypertension. © 2015, Springer-Verlag Berlin Heidelberg.

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