A Experiment Research About The Antagonistic Effect Of G31P Against IL-8 Of HaCaT In Vitro And Mice Model Of Psoriasis

Psoriasis is a common, easy to relapse, chronic and inflammatory skin disease with multiple genetic defected , which pathogenesis has not been elucidated. In recent years, with the cyclosporine A ----T cell inhibitor was found to improve psoriasis significantly, psoriasis is defined as a T-cell- mediated disease. As a chronic inflammatory disease, psoriasis showed clinical erythema, scales, desquamation and itching so seriously that affected the quality of life of patients, an important performance in the major histopathological features of which is neutrophils into the epidermis and the formation of Munro micro-abscesses, besides for the excessive proliferation of epidermal cells, differentiation was incomplete, superficial dermal telangiectasia, inflammatory cells and promote excessive histamine release. Moreover, IL-8 is considered to be an important mediator in the process that the infiltration of neutrophils, transport of white blood cells and the chemotaxis movement and excessive proliferation of a variety of cells. In this study, we used IL-8 receptor antagonist to competitively inhibit the role of IL-8, to detected the antagonistic effect of G31P against the IL-8 in the course of psoriasis.Objective To research the proliferative effect of IL-8 for the HaCaT cells and its promotive role in the development of psoriasis, and the competitive inhibition of the receptor antagonist of IL-8 ----G31P.Methods In vitro: Cultured HaCaT cells treated with the different concentrations of IL-8, observe the cellular proliferation assessed by CCK-8 method; then, Cultured HaCaT cells treated with the same concentrations of IL-8 and its receptor antagonist ----G31P ; and assessed the Cellular proliferation by CCK-8 method, the changes of mRNA expression of IL-8 by reverse transcription PCR, the level of IL-8 protein expression in the supernate by ELISA. In vivo: the ears of the psoriasis mice models were injected with the appropriate concentration and volume of G31P through the way of intradermal injection, the control group injected with 0.9% Nacl for every second day, after 21 days, assessed the changes of mRNA expression of IL-8 in the ears of the model by reverse transcription PCR, the differences of the cytokine marker and appearance of ears between the esperimental group and control group.Results The cell proliferation could be accelerated by IL-8 with different concentration, which was depended by the proliferation. The proliferation of HaCaT cell would be inhibited by G31P notably. And the level of RNA and protein of cells obviously lowered down when the cells were cultured with the IL-8 and the G31P. the concentration of the CXCL-1(IL-8) in the mice model ears with the treatment of G31P is lower than that in the mice without the treatment, and the detected cytokine matker decreased, too. HE staining result showed that the thickness of the ear cuticle and the cell number and morphology were significantly different.Conclution IL-8 could promote the development of psoriasis through the promotion of epidermal cells and other ralevent cell proliferation in the pathogenesis of psoriasis. It can promote the transformation from monocytes to macrophages,and with the certain concentration, the KC proliferation depends the different concentration of IL-8. G31P could bind to the CXCR1/2 of IL-8, and inhibit the psoriasis through against the effect of IL-8.