TGF-beta inhibits IL-1beta-activated PAR-2 expression through multiple pathways in human primary synovial cells.
To investigate the mechanism how Transforming growth factor-beta(TGF-beta) represses Interleukin-1beta (IL-1beta)-induced Proteinase-Activated Receptor-2 (PAR-2) expression in human primary synovial cells (hPSCs). Human chondrocytes and hPSCs isolated from cartilages and synovium of Osteoarthritis (OA) patients were cultured with 10% fetal bovine serum media or serum free media before treatment with IL-1beta, TGF-beta1, or Connective tissue growth factor (CTGF). The expression of PAR-2 was detected using reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. Collagen zymography was performed to assess the activity of Matrix metalloproteinases-13 (MMP-13). It was demonstrated that IL-1beta induces PAR-2 expression via p38 pathway in hPSCs. This induction can be repressed by TGF-beta and was observed to persist for at least 48 hrs, suggesting that TGF-beta inhibits PAR-2 expression through multiple pathways. First of all, TGF-beta was able to inhibit PAR-2 activity by inhibiting IL-1beta-induced p38 signal transduction and secondly the inhibition was also indirectly due to MMP-13 inactivation. Finally, TGF-beta was able to induce CTGF, and in turn CTGF represses PAR-2 expression by inhibiting IL-1beta-induced phospho-p38 level. TGF-beta could prevent OA from progression with the anabolic ability to induce CTGF production to maintain extracellular matrix (ECM) integrity and to down regulate PAR-2 expression, and the anti-catabolic ability to induce Tissue inhibitors of metalloproteinase-3 (TIMP-3) production to inhibit MMPs leading to avoid PAR-2 over-expression. Because IL-1beta-induced PAR-2 expressed in hPSCs might play a significantly important role in early phase of OA, PAR-2 repression by exogenous TGF-beta or other agents might be an ideal therapeutic target to prevent OA from progression.
Tsai
Shin-Han
SH
Department of Neurosurgery, Department of Emergency and Critical Care Medicine, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan, Republic of China. shtsai@tmu.edu.tw
Sheu
Ming-Thau
MT
Liang
Yu-Chih
YC
Cheng
Hsiu-Tan
HT
Fang
Sheng-Shiung
SS
Chen
Chien-Ho
CH
D003094:Collagen / Q000737:chemistry; D055513:Connective Tissue Growth Factor / Q000378:metabolism; D016895:Culture Media, Serum-Free; D018450:Disease Progression; D005109:Extracellular Matrix / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism*; D010003:Osteoarthritis / Q000188:drug therapy; D044464:Receptor, PAR-2 / Q000096:biosynthesis*; D015398:Signal Transduction; D013583:Synovial Membrane / Q000201:enzymology*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D016895:Culture Media, Serum-Free; D053583:Interleukin-1beta; D044464:Receptor, PAR-2; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor; D003094:Collagen; D048051:p38 Mitogen-Activated Protein Kinases