ABSTRACT
This paper is aimed to investigate the effect of titanium (Ti) particles and tumor necrosis factor alpha (TNF-alpha) on the expressions of MMP-1, 2, 3 in human synovial cells, so as to explore the possible mechanism of osteolysis post-operation of metal-on-metal total joint arthroplasty in human synovial cells induced by Ti particles. In vitro cell cultures, human synovial cells were treated by Ti particles and/or TNF-alpha. The total RNA was isolated at 2 hours after the treatment. The gene expression of MMP-1, 2, 3 was analyzed by Semi-quantitative Reverse-transcriptional PCR and quantitative real-time PCR. Cell supernatant was collected at 12, 24, 48 hours after the treatment and Gelatin zymography was performed to detect the activity of MMP-2. Compared to those in the control group (untreated), Ti particles and TNF-alpha increased the gene expression of MMP-1, 2, 3 respectively (P < 0.05), and the effect of combination of the two was even more significant (P < 0.01). The trend of activities of MMP-2 is similar with gene expression. Ti particles and TNF-alpha increased MMP-2 activities by 1.3 times and 1.5 times respectively (P < 0.05), and the combination of the two increased by 1.7 times (P < 0.01). Ti particles and TNF-alpha-induced the stimulation of MMP-1, 2, 3 expressions and MMP-2 activities in human knee joint synovial cells may be involved in aseptic loosening after metal-on-metal arthroplasty through increasing the degradation of bone matrix and declining of osseous support structure mechanics.
Subject(s)
Humans , Cells, Cultured , Joint Prosthesis , Knee Joint , Cell Biology , Matrix Metalloproteinase 1 , Genetics , Metabolism , Matrix Metalloproteinase 2 , Genetics , Metabolism , Matrix Metalloproteinase 3 , Genetics , Metabolism , Matrix Metalloproteinases , Genetics , Metabolism , Particle Size , Prosthesis Failure , RNA , Genetics , Metabolism , Synovial Membrane , Cell Biology , Titanium , Pharmacology , Tumor Necrosis Factor-alpha , PharmacologyABSTRACT
Sulfur compounds in the diesel were selectively derived into methylsulfonium salts by reacting with iodomethane in the presence of silver tetrafluoroborate, and characterized by positive-ion electrospray ionization (ESI) fourier transform ion cyclotron resonance (FT-ICR MS). The conversion ratios and react selectivities of the methylation for various sulfur compounds were investigated by gas chromatograph coupled with pulse flame photometric detector (GC-PFPD). Result shows that the sulfur compounds in the diesel can react with iodomethane easily at room temperature, the most of sulfur compound derived into methylsulfonium salts;the homologue of benzothiophene get the higher conversion ratio and react selectivity than the homologue of dibenzothiophene (DBT). It is found that primarily sterically hindered alkylated DBT, for example, 4- or 4-, 6- DBT, is recalcitrant to be methylated. Other than benzothiophenes and dibenzothiophenes, one- and two-ring sulfides, as well as other sulfur compounds with a double bond equivalent (DBE) value ranged from 1 to 12 are identified in the diesel.