Effect Of FY-10 On Expression Of Cyclooxygenase-2 MRNA And Tumor Necrosis Factor-α MRNA In Keratinocyte

Psoriasis is an autoimmune disease mediated by T lymphocyte.It is a common chronic inflammatory skin disease.High level of cytokines correlative with inflammation can be detected in the peripheral blood and the lesion of patients with psoriasis, such as prostaglandin E2 (PGE2) . Cyclooxygenase is the key enzyme which catalyze arachidonic acid into PGE2. COX-2, the induced isozyme of cyclooxygenase, is a 71kD membrane conjugated protin, and correlative to inflammation response. Tumor necrosis factor (TNF), the cytokine secreted by macrophage and lymphocyte, has a close relationship with keratinocyte.Keratinocytes of healthy persons and the patients with tumor or psoriasis can produce TNF. Meanwhile, TNF can affect the form and function of keratinocytes. TNF plays an important role in the inflammatory reaction: TNF-a induces the expression of the inflammation mediums such as interleukin-1 (IL-1) and intercellular adhesion molecule-1 (ICAM-1) , which results in the infiltration of inflammatory cells.Many studies about COX-2 have been reported in the field of inflammation andneoplasm, also in the pathogenesis of dermatosis especially psoriasis.But there is noreport yet about whether retinoic acid has the influence to COX-2 mRNA expression.Retinoic acids can inhibit the proliferation of epidermic cell, promotedifferentiation of keratinocyte and decrease inflammation.It has attain goodclinical effect in treatment of psoriasis , either used alone or combined with othermethods. It's mechanism has not been elucidated clearly , but perhaps relates withthe three factors mentioned above. In addition, whether FY-10 has the activity ofanti-inflammation is still unknown.We set up the inflammatory cell-model similar topsoriasis keratinocyte by use of LPS in HaCaT cell line to observe the effect ofFY-10 and other examined agents on the COX-2 and TNF-a mRNA, thus evaluatethe anti-inflammation activity of FY-10 and other agents. Our experimentdemonstrates that FY-10 can definitely decrease the express of COX-2 and TNF-amRNA in HaCaT cell line.lt provides a theoretic support to the application of FY-10 in therapy of psoriasis.Part I Expression of cyclooxygenase 2 mRNA in HaCaT cell lineObjective: To observe the expression of cyclooxygenase 2 mRNA of humankeratinocytes.Method: Cyclooxygenase 2 mRNA expression of HaCaT cell line in vitro-culturedwas determined by reverse transcriptase polymerase chain reaction(RT-PCR) beforeand after treatment of lipopolysaccharide.Result: 1. In vitro-cultured HaCaT cell line can expresse COX-2 mRNAspontaneously. 2. The expression of cyclooxygenase-2 mRNA was significantlyup-regulated after HaCaT cell line being treated with LPS of 5~lQug/L finalconcentration.Conclusion : Keratinocyte of healthy human can express cyclooxygenase 2 mRNA.which can be up-regulated by lipopolysaccharide.Part II Effect of FY-10 on the cyclooxygenase 2 mRNA expression ofHaCaT cell lineObjective: To observe the effect of FY-10 on the expression of cyclooxygenase2 mRNA in HaCaT cell line.Method: Lipopolysaccharide-induced COX-2 mRNA expression of in vitro-cultured human keratinocyte was determined by RT-PCR before and after treatment of FY-10 or Acitretin.Result: 1. Either FY-10 or Acitretin can distinctly downregulate the expression of COX-2 mRNA induced by LPS. 2. The effect of FY-10 is strongest in 10'6M. Conclusion: FY-10 can downregulate the expression of cyclooxygenase 2 mRNA of HaCaT cell line definitely.