Association between matrix metalloproteinase-1 (MMP-1) protein level and the risk of rheumatoid arthritis and osteoarthritis: a meta-analysis

Recent publications have investigated the potential role of the protein level of matrix metalloproteinase-1 (MMP-1) in the susceptibility to rheumatoid arthritis (RA) and osteoarthritis (OA). However, no unanimous conclusion was obtained. Therefore, we carried out a meta-analysis to explore the association between MMP-1 expression and these two clinical disorders. After database searching and screening, we enrolled a total of eighteen articles for the pooled analysis. We observed a significant association between RA cases and controls in the whole population [SMD (standard mean difference)=1.01, P=0.017]. There were similar positive results in the subgroup analysis of "population-based control" (SMD=1.50, P=0.032) and "synovial fluid" (SMD=1.32, P=0.049). In addition, we observed an increased risk in OA cases, compared with controls, in the overall analysis (SMD=0.47, P=0.004) and subsequent subgroup analysis of "knee OA" (SMD=0.86, P<0.001), "Asian/China" (SMD=0.76, P=0.003), "cartilage-Asian/China" (SMD=1.21, P<0.001), and "synovial fluid-Asian/China" (SMD=0.73, P=0.004). In summary, a high protein level of MMP-1 in synovial fluid may be associated with the susceptibility to RA, and the high MMP-1 level in the cartilage tissue or synovial fluid may be related to the pathogenesis of knee OA in the Chinese population. This should be confirmed by larger sample sizes.

Construction of Eukaryotic Expression Plasmid of hTGF-β3 and Its Inducing Effect on Differentiation of Precartilaginous Stem Cells into Chondroblasts / 华中科技大学学报（医学）（英德文版）

This study examined the construction of eukaryotic expression plasmid of human transforming growth factor-β3 (hTGF-β3) and its inducing effect on the differentiation of precartilaginous stem cells (PSCs) into chondroblasts.hTGF-β3 gene was amplified by using polymerase chain reaction (PCR) and then inserted into the eukaryotic expression plasmid pcDNA3.1 to construct the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3.Rat PSCs were isolated and purified by employing an immunomagnetic cell sorting system.pcDNA3.1(+)-hTGF-β3 was transfected into purified PSCs with the use of linear polyamines.The expression of TGF-β3 and cartilage-specific extracellular matrix (ECM)components was detected after transfection by real-time quantitative PCR,ELISA,immunochemistry and Western blotting,respectively.The results showed that the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3 was successfully established as identified by enzyme digestion and DNA sequencing.Real-time quantitative PCR and ELISA revealed that hTGF-β3 was strongly expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs.Real-time quantitative PCR,immunochemistry and Western blotting showed that the cartilage-specific ECM markers,i.e.,cartilage oligomeric matrix protein (COMP),Aggrecan,collagen type Ⅹ and Ⅱ were intensely expressed in the pcDNA3.1(+)-hTGF-β3-transfected cells.It was concluded that hTGF-β3 could be stably expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs and induce the differentiation of PSCs into chondroblasts.