ABSTRACT
<p><b>OBJECTIVE</b>To explore the effects of down-regulated tryptase expression in mast cells on the synthesis and release of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) of vascular endothelial cells.</p><p><b>METHODS</b>Tryptase-siRNA (small-interfering RNA) vector was constructed to inhibit tryptase expression in P815 cells. The medium of P815 cells treated by the tryptase-siRNA (RNAi-P815 group) or pure vector (P815 group) was collected and used to culture bEnd.3 cells. The messenger RNAs (mRNAs) of IL-6 and TNF-alpha in bEnd.3 cells and their protein levels in the medium were measured by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively.</p><p><b>RESULTS</b>IL-6 and TNF-alpha mRNAs in bEnd.3 cells cultured in RNAi-P815-conditioned medium decreased significantly compared to those in P815-conditioned medium. Consistently, IL-6 and TNF-alpha protein levels in the medium of bEnd.3 of RNAi-P815 group were lower than those of P815 group.</p><p><b>CONCLUSION</b>Reduced tryptase expression significantly inhibited the synthesis and release of IL-6 and TNF-alpha in vascular endothelial cells. RNA interference targeting tryptase expression may be a new anti-inflammatory strategy for vascular diseases.</p>
Subject(s)
Animals , Mice , Cell Line , Culture Media, Conditioned , Down-Regulation , Genetics , Endothelial Cells , Bodily Secretions , Gene Expression Regulation, Enzymologic , Interleukin-6 , Genetics , Bodily Secretions , RNA, Messenger , Genetics , RNA, Small Interfering , Genetics , Transgenes , Tryptases , Genetics , Metabolism , Tumor Necrosis Factor-alpha , Genetics , Bodily SecretionsABSTRACT
<p><b>BACKGROUND</b>Protease activated receptor-2 is cleaved and activated by trypsin or mast cell tryptase and may play an important role in inflammation. However, it is unknown whether PAR-2 can mediate tryptase-induced inflammatory reaction. This study was conduct to investigate whether PAR-2 could be the activated by mast cell tryptase and medicated the tryptase induced interleukin-8 expression in endothelial cells.</p><p><b>METHODS</b>Protease activated receptor-2 expression was found in endothelial cell lines ECV304 cell by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Interleukin-8 stimulated by purified human mast cell tryptase was determined by RT-PCR and enzyme linked immunosorbent assay (ELISA). Data were analysed by the S-N-K one-way ANOVA test.</p><p><b>RESULTS</b>The present study shows that mRNA and protein of protease activated receptor-2 could be expressed in ECV304 cells, and tryptase upregulated the expression levels of both interleukin-8 mRNA and protein. The increased expression of interleukin-8 was inhibited by an antiprotease activated receptor-2 monoclonal antibody, SAM11. An additional band was observed by Western blotting after the incubation of ECV304 cells with tryptase for 2 hours, which suggested that protease activated receptor-2 was activated.</p><p><b>CONCLUSION</b>Protease activated receptor-2 can mediate the mast cell tryptase stimulated expression of interleukin-8 in ECV304 cell.</p>
Subject(s)
Humans , Antibodies, Monoclonal , Allergy and Immunology , Cell Line , Endothelial Cells , Metabolism , Gene Expression Regulation , Interleukin-8 , Genetics , RNA, Messenger , Receptor, PAR-2 , Genetics , Physiology , Serine Endopeptidases , Physiology , Tryptases , Up-RegulationABSTRACT
Objective To design,synthesize and screen high efficient small interfering RNA(siRNA) targeting to cyclooxygenase-2(COX-2)on rheumatoid arthritis synovial fibroblasts(RASF).To further study the effect of specific COX-2 siRNA interfering on mediators of inflammatory cytokines.Methods Four pairs of siRNA for human COX-2 mRNA were synthesized by utilizing RNA design software,while another random sequence was designed as control.They were divided into group A to H.Among them,group A was used as the negative control(CTL),and group B to F were transfected as random siRNA(NC),1#～4#siRNA in order. These siRNAs were transferred into RASF by LipofectAMINE2000 package and PMA(phorbol-12-myristate- 13-acetate)was added into each culture and with a final concentration of 100 nmol/l.RASF was collected 48 hours after transfection.The expression of hCOX-2 at mRNA level was determined by reverse transcription- polymerase chain reaction(RT-PCR)and hCOX-2 protein level by Western Blot.The supernatant levels of PGE_2,IL-1?,IL-6,TNF-?and vascular endothelial growth factor(VEGF)of the above groups were detected by ELISA.Results The levels of hCOX mRNA and protein in RASF treated with 4-#siRNA were significantly lower than those of the negative control and other groups.The level of PGE_2 and cytokines like IL-1?,IL-6, TNF-?and VEGF in the supernatant were lower in the 4#siRNA group than in other groups.Conclusion 4#siRNA can effectively inhibit the expression of COX-2 mRNA and the synthesis of the COX-2 protein in human synovial fibroblasts.The level of PGE_2,IL-1?,IL-6,TNF-?and VEGF is the lowest in the super- natant.Thus 4#siRNA has been confirmed to specifically block the COX-2 in human synovial fibroblasts.