[Research of the expression of subchondral bone of Indian hedgehog with early experimental osteoarthritis induced by mechanical stress].

Objective: To investigate the the expression of subchondral bone of Indian hedgehog(Ihh) with early experimental osteoarthritis induced by mechanical stress. Methods: The animals were equally divided into two groups: experimental group(E-group, n=15) and control group(S-group, n=15). The right knee joints of E-group underwent surgery, which involved in both medial collateral ligament (MCL) transaction and medial meniscectomy, while the control group was only carried out with a sham operation.The rats were killed at 1, 2 and 4 weeks postsurgery to obtain the right knee joints. Immunostaining and immunofluorescence double staining were performed to evaluate the expression of Ihh in subchondral bone, respectively. Results: The polynuclear giant cells in the subchondral bone of E-Group expressed Ihh in their cytoplasm 1 and 2 weeks post-surgery, except for 4 week, while those of S-Group appeared negative at all three time points postsurgery. There is statistically difference between the mean density of positive area of Ihh in sections of E-group and S-group both in 1 week (E-group: 0.351+ 0.086, S-group: 0.153±0.017, P<0.05) and 2 weeks (E-group: 0.303±0.026, S-group: 0.176±0.013, P<0.05), but without statistically difference in 4 weeks (E-group: 0.092±0.033, S-group: 0.136±0.014, P>0.05) post surgery. Trap positive giant cells in subchondral bone of E-group were also found Ihh positive, which indicated expression of Ihh in osteoclast . Conclusion: Ihh maybe play an important role in pathogenesis of early experimental osteoarthritis.

Mechanical stress contributes to osteoarthritis development through the activation of transforming growth factor beta 1 (TGF-ß1).

OBJECTIVES: The role of mechanical stress and transforming growth factor beta 1 (TGF-ß1) is important in the initiation and progression of osteoarthritis (OA). However, the underlying molecular mechanisms are not clearly known. METHODS: In this study, TGF-ß1 from osteoclasts and knee joints were analyzed using a co-cultured cell model and an OA rat model, respectively. Five patients with a femoral neck fracture (four female and one male, mean 73.4 years (68 to 79)) were recruited between January 2015 and December 2015. Results showed that TGF-ß1 was significantly upregulated in osteoclasts by cyclic loading in a time- and dose-dependent mode. The osteoclasts were subjected to cyclic loading before being co-cultured with chondrocytes for 24 hours. RESULTS: A significant decrease in the survival rate of co-cultured chondrocytes was found. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay demonstrated that mechanical stress-induced apoptosis occurred significantly in co-cultured chondrocytes but administration of the TGF-ß1 receptor inhibitor, SB-505124, can significantly reverse these effects. Abdominal administration of SB-505124 can attenuate markedly articular cartilage degradation in OA rats. CONCLUSION: Mechanical stress-induced overexpression of TGF-ß1 from osteoclasts is responsible for chondrocyte apoptosis and cartilage degeneration in OA. Administration of a TGF-ß1 inhibitor can inhibit articular cartilage degradation.Cite this article: R-K. Zhang, G-W. Li, C. Zeng, C-X. Lin, L-S. Huang, G-X. Huang, C. Zhao, S-Y. Feng, H. Fang. Mechanical stress contributes to osteoarthritis development through the activation of transforming growth factor beta 1 (TGF-ß1). Bone Joint Res 2018;7:587-594. DOI: 10.1302/2046-3758.711.BJR-2018-0057.R1.

[A recombinant fowlpox virus expressing the fusion protein of Newcastle disease virus strain F48E8 and its protective efficacy].

The transfer vector pFGF1175-1 was constructed by insertion the fusion protein gene of Newcastle disease virus (NDV) F48E8 strain into the insertion vector pFG1175-1, downstream of P7.5 promotor, and then transfected chicken embryo fibroblast (CEF) cell cultures which had been infected with fowlpox virus (FPV) Chinese vaccine strain 282E4 for 3-4 hours. Recombinant FPV with blue plaques were selected and purified in CEF cell culture laid agar containing X-gal. The recombinant FPV named rFPV-NDF was confirmed expressing NDV fusion protein by indirect immunofluorescence assay, and could protect chickens against virulent NDV challenge, The protective rate was 96.7%.