title: Mechanical stretch regulates the expression of matrix metalloproteinase in rheumatoid arthritis fibroblast-like synoviocytes.
abstract: Mechanical stretch plays a crucial role in articular joints. In rheumatoid arthritis (RA), it is well known that fibroblast-like synoviocytes (FLS) produce matrix metalloproteinases (MMPs), resulting in local invasion into and degradation of bone and cartilage. We sought to examine whether mechanical stretch regulates the expression and underlying signal pathways of MMP secretion (MMP-1, -3, -13) in RA-FLS. FLS were grown on elastic silicone membrane in an equibiaxial strain apparatus and were exposed to 6% mechanical stretch (equivalent to gentle stretch exercise) for 15 min and 75 min, respectively. Semiquantitative PCR and real-time PCR were used to measure and analyze gene expression. Protein levels were determined by Western blotting. The results showed that 15 min of mechanical stretch inhibited MMP-1 and MMP-13 mRNA and protein level. However, the degree of inhibition by 75 min of stretch in expression of MMP-1 and MMP-13 was lower compared with 15 min stretch groups. The mRNA expression of ERK-1, ets-1 and citied-2 were increased by 6% mechanical stretch under both time points, however c-jun and c-fos mRNA level were affected differently after 15 min and 75 min mechanical stretch compared to control group. There were no significant changes on MMP-3 and ets-2 mRNA level under both 6% mechanical stretch time points. In the presence of pro-inflammatory cytokines (IL-1beta and TNF-alpha), the stretch also reduced the mRNA expression of MMP-1 and MMP-13. In short, our results showed that gentle mechanical strain affects MMP-1 and MMP-13 expression, potentially through the ERK-1-ets-1-cited-2-c-jun signaling pathway.
authors.affiliation: College of Bioengineering, Chongqing University, Chongqing, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: You
authors.forename: Gurinder K
authors.initials: GK
authors.lastname: Singh
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: K L Paul
authors.initials: KL
authors.lastname: Sung
mesh_terms: D001172:Arthritis, Rheumatoid / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D015153:Blotting, Western; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology*; D005786:Gene Expression Regulation; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013314:Stress, Mechanical; D013583:Synovial Membrane / Q000187:drug effects / Q000201:enzymology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C494041:ETS1 protein, human; D053583:Interleukin-1beta; D050784:Proto-Oncogene Protein c-ets-1; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D048052:Mitogen-Activated Protein Kinase 3; D020782:Matrix Metalloproteinases