ABSTRACT
OBJECTIVE: Traumatic arthritis is one of the most common diseases in orthopedics. LGR4 is involved in bone formation and bone development. However, the role of LGR4 in synovial cells of rats with traumatic osteoarthritis has not been reported. MATERIALS AND METHODS: Sprague Dawley (SD) rats were randomly divided into the control group and model group. The Real Time-Polymerase Chain Reaction (RT-PCR), Western blot, and Enzyme-Linked Immunosorbent Assay (ELISA) were used to analyze the expression of LGR4 in synovial tissue and synovial fluid. Synovial cells were isolated and cultured, followed by transfection of LGR4-pcDNA3.1 plasmid into cells. Cell proliferation was analyzed by MTT and EdU assay, and the Caspase-3 activity was assessed using the Caspase-3 activity kit. The secretion of the inflammatory factors interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) was detected by ELISA. NF-κB signaling pathway changes were evaluated by the Western blot. RESULTS: In the model group, LGR4 mRNA expression in synovial tissue was significantly decreased, and the secretion of LGR4 in the synovial fluid was significantly decreased compared with the control group (p<0.05). LGR4 protein expression in the synovial membrane in the model group tissue was reduced. The transfection of LGR4-pcDNA3.1 plasmid into synovial cells promoted the LGR4 expression, inhibited the proliferation of synoviocytes, increased the Caspase-3 activity, the secretion of IL-1, TNF-α, and IL-6, as well as the decreased expression of NF-κB with a statistical significance, compared with the control group (p<0.05). CONCLUSIONS: LGR4 expression is reduced in the rat model of traumatic osteoarthritis. The upregulation of LGR4 expression can inhibit the secretion of the inflammatory factors and inhibit the proliferation of the synovial cells by regulating NF-κB signaling pathway, which may alleviate the development of the joint inflammation.
Subject(s)
Cell Proliferation , Immunologic Factors/immunology , Osteoarthritis/immunology , Receptors, G-Protein-Coupled/metabolism , Synoviocytes/immunology , Animals , Cells, Cultured , Disease Models, Animal , Immunologic Factors/genetics , Interleukin-1/genetics , Interleukin-1/immunology , Interleukin-6/genetics , Interleukin-6/immunology , Male , NF-kappa B/metabolism , Osteoarthritis/metabolism , Osteoarthritis/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, G-Protein-Coupled/genetics , Signal Transduction , Synoviocytes/metabolism , Synoviocytes/pathology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
Tumors consistently mimic wound-generating chronic inflammation; however, why they do not heal like wounds with fibrotic scars remains unknown. The components of the tumor microenvironment, such as transforming growth factor ß (TGF-ß) and fibroblast growth factors (FGFs), may account for this phenomenon. Tumor formation involves continuous activation of the FGF pathway, whereas the repair of tissue injury is a self-limiting process accompanied with controlled activation of the FGF pathway. In the tumor microenvironment TGF-ß increases the secretion of FGFs, further promoting the malignant biological properties of tumors. However, during wound healing, sufficient TGF-ß together with moderate FGFs lead to matrix deposition and the formation of fibrotic scars. In the present study, TGF-ß1 combined with AZD4547, an FGF receptor (FGFR) inhibitor, transformed hepatoma cells into less malignant fibroblast-like cells with respect to morphology, physiological properties, and gene expression profiles. In vivo experiments showed that TGF-ß1 combined with AZD4547 not only inhibited tumor growth but also promoted tumor parenchyma fibrosis. Our results indicate that FGFR inhibitor treatment converts the effect of TGF-ß on the hepatocellular carcinoma cells from tumor promotion into tumor inhibition by enhancing the induction effect of TGF-ß on some fibroblast-associated genes. Converting human liver cancer cells into less malignant fibroblast-like cells and inducing tumor parenchyma cell fibrosis provides an alternative strategy for limiting tumor progression.
Subject(s)
Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Transcriptional Activation/drug effects , Transforming Growth Factor beta1/physiology , Animals , Benzamides , Carcinoma, Hepatocellular/pathology , Cell Proliferation , Gene Expression , Gene Expression Regulation, Neoplastic , Hep G2 Cells , Humans , Liver Neoplasms/pathology , Male , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , Piperazines , Pyrazoles , Receptors, Fibroblast Growth Factor/metabolism , Tumor MicroenvironmentABSTRACT
Rhodotorula glutinis RG6 was treated by high hydrostatic pressure (HHP) of 300 MPa for 15 min for improving its ability of beta-carotene production. After the treatments of 5 repeated cycles, the mutant strain RG6p was obtained, beta-carotene production of which reached 10.01 mg/L, increased by 57.89% compared with 6.34 mg/L from parent strain RG6. To optimize the medium for beta-carotene fermentation by mutant RG6p, a response surface methodology (RSM) approach was used in conjunction with a factorial design and a central composite design, and the maximum yield of beta-carotene (13.43 mg/L), an increase of 34.17% compared to the control, was obtained at a pH 6.7 with an optimum medium (40 mL/250 mL) of yeast extract (4.23 g/L), glucose (12.11 g/L), inoculum (30 mL/L), tomato extract (2.5 mL/L), peanut oil (0.5 mL/L), and (NH(4))(2)SO(4) (5 g/L).
