ABSTRACT
Osteoarthritis (OA) is a common and dynamic disease of the joints, including the articular cartilage, underlying bones and synovium. In particular, OA is considered as the degeneration of the cartilage. Tectorigenin (Tec) is known to affect many biological processes; however, its effects on articular chondrocytes remain unclear. This study aimed to assess the effects of Tec on articular cartilage. In vitro, Tec inhibited the expression levels of type X collagen, cyclooxigenase-2, matrix metalloproteinase (MMP)-3 and MMP-13, but enhanced the expression of Runx1, type II collagen and aggrecan in the presence of IL-1ß. Meanwhile, Tec inhibited apoptosis through the Bax/Bcl-2/caspase-3 pathway, upregulating p-Bad, downregulating the Bax/Bcl-2 ratio, and activating caspase-3 compared with IL-1ß treatment only. Moreover, this process was partially regulated by NF-κB P65. In vivo, the chondroprotective effects of Tec were assessed by establishing a model of surgically induced OA. Tec-treated joints exhibited fewer osteoarthritic changes than saline-treated joints. Meanwhile, 1.5â µg/kg Tec treatment produced a greater protective effect than 0.75â µg/kg Tec. The Osteoarthritis Research Society International (OARSI) scoring system, employed to assess histopathological grading of the models, as well immunohistochemistry for Aggrecan Neoepitope and MMP-3, further confirmed the results. In conclusion, this study showed that Tec plays a chondroprotective role in the OA process by preventing articular cartilage degeneration and chondrocyte apoptosis via the NF-κB P65 pathway.
ABSTRACT
Developmental dysplasia of the hip (DDH) is a common musculoskeletal disorder characterized by a mismatch between acetabulum and femoral head. Mechanical force plays an important role during the occurrence and development of abnormities in acetabulum and femoral head. In this study, we established a mechanical force model named cyclic compressive stress (Ccs). To analyze the effect of Ccs on DDH, we detected special genes in chondrocytes and osteoblasts. Results showed that Ccs downregulated chondrogenesis of ADTC5 in a concentration-dependent manner. Moreover, the mRNA level of Scinderin (Scin) considerably increased. We established lentivirus-SCIN(GV144-SCIN) to transfect hBMSCs, which were treated with different Ccs levels (0.25 Hz*5 cm, 0.5 Hz*5 cm, and 1 Hz*10 cm); the result showed that overexpression of Scin upregulated osteogenesis and osteoclastogenesis. By contrast, expression of chondrocyte-specific genes, including ACAN, COL-2A, and Sox9, decreased. Further molecular investigation demonstrated that Scin promoted osteogenesis and osteoclastogenesis through activation of the p-Smad1/5/8, NF-κB, and MAPK P38 signaling pathways, as well as stimulated the expression of key osteoclast transcriptional factors NFATc1 and c-Fos. Moreover, Scin-induced osteogenesis outweighed osteoclastogenesis in defective femur in vivo. The results of the analysis of Micro-CT confirmed these findings. Overall, Ccs influenced the development of DDH by promoting osteogenesis and cartilage degradation. In addition, Scin played a vital role in the development of DDH.
Subject(s)
Gelsolin/genetics , Gene Expression Regulation , Hip Dislocation, Congenital/genetics , Stress, Mechanical , Animals , Blotting, Western , Cell Line, Tumor , Cells, Cultured , Chondrocytes/metabolism , Chondrogenesis/genetics , Disease Progression , Gelsolin/metabolism , Hip Dislocation, Congenital/metabolism , Hip Dislocation, Congenital/pathology , Humans , MAP Kinase Signaling System , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/metabolism , Mice, Nude , NF-kappa B/metabolism , Osteoblasts/metabolism , Osteogenesis/genetics , Rats , Reverse Transcriptase Polymerase Chain Reaction , Transplantation, HeterologousABSTRACT
Osteoblasts are essential for maintaining skeletal architecture and modulating bone microenvironment homeostasis. From numerous associated investigations, the BMP-2 pathway has been well-defined as a vital positive modulator of bone homeostasis. Gremlin2 (Grem2) is a bone morphogenetic protein (BMP) antagonists. However, the effect of Grem2 on the BMP-2-induced osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMSCs) remains ambiguous. This study aimed to analyze the procedure in vitro and in vivo. The differentiation of hBMSCs was assessed by determining the expression levels of several osteoblastic genes, as well as the enzymatic activity and calcification of alkaline phosphatase. We found that Grem2 expression was upregulated by BMP-2 within the range of 0-1 µg/mL, and significant increases were evident at 48, 72, and 96 h after BMP-2 treatment. Si-Grem2 increased the BMP-2-induced osteogenic differentiation of hBMSCs, whereas overexpression of Grem2 had the opposite trend. The result was confirmed using a defective femur model. We also discovered that the BMP-2/Smad/Runx2 pathway played an important role in the process. This study showed that si-Grem2 increased the BMP-2-induced osteogenic differentiation of hBMSCs via the BMP-2/Smad/Runx2 pathway. J. Cell. Biochem. 118: 286-297, 2017. © 2016 Wiley Periodicals, Inc.