The Expression And Significance Of MIF, MMP-9 And TNF-α In Psoriasis

Objectives: Psoriasis is a chronic and relapsing inflammatory skin disease, which has a long course especially in youth adults and also has a considerable effect on psychology and spiritual health of patients. At the present most scholars consider that Psoriasis is an abnormal immune inflammatory disease with multi-gene genetic background which is related to various reasons such as immunity, inflammation, cell proliferation and apoptosis, and abnormal microvessel. Its exact pathogenesis is not yet clear. There is much evidence suggested that T cells may play a central role in the pathogenesis of psoriasisMacrophage migration inhibitory factor (MIF), initially considered to be a kind of lymphatic factor of T-cell origin, found that in vitro the anti-MIF antibodies inhibited T-cell proliferation and IL - 2 formation, in vivo inhibited antigen activated T cells activation and antibody production. Keratinocytes (KC), fibroblasts (FB) cells and extracellular matrix (ECM) compose the skin. ECM is a micro-environment of the cells and produced an important influence on their lives process, the structure and function. More researches have been confirmed, ECM abnormalities may play an important role in the pathogenesis of psoriasis. Matrix metalloproteinases (MMPs) are the main ECM degradation enzymes, MMP-9 is one of its members. A study showed that MIF could increase the expression of MMP-9. TNF-αas a proinflammatory factor may play a pivotal role in the occurrence and development of psoriasis. Researches show that MIF can stimulate macrophage expression of TNF-αand other cytokines. In this study we investigated the expressions of MIF,MMP-9 and TNF-αwith immunohistochemical technique in psoriatic lesions and the healthy skin.Methods: Lesion samples were derived from the clinic attendance patients of the dermatology department, the Fourth Affiliated Hospital of Hebei Medical University from October 2004 to October 2006. 30 cases specimens of patients with psoriasis were chosen who were confirmed by clinical and pathology; men 16 cases , women 14 cases; aged 7-68 years old, with an average age of 29.1. All patients did not have other systemic diseases and had not received any treatment in the past three months. Control group specimens were derived from 20 cases of traumatic surgery patients with the health skin of the Fourth Affiliated Hospital, Hebei Medical University. The control group patients did not suffering from other diseases, and the age, sex and location were matching with psoriasis patients. Paraffin section was used by HE staining in histopathology. The expressions of MIF,MMP-9 and TNF-αin the lesion samples with psoriasis and the health control group were detected by immunohistochemical SP method. The experimental results were analyzed by SPSS11.5, one kind of statistical analysis software. In the immunohisto -chemistry results, The Mann-Whitney U test was used to analysis the indicators in the PS group and the control group expression. The Spearman rank correlation analysis was used to check the relevance of MIF, MMP-9 and TNF-α. p<0.05 is signifancant.Results1 Pathological examination revealed that: 30 selected PS cases were seen dermal papilla telangiectasia achieving to the top and superficial layer perivascular mononuclear cell infiltration. Nearly 53% (16/30) of cases that stratum spinosum epidermidis acanthosis, trochanterellus extension and the extension of roughly the same level surface. About 67% (20/30) were visible parakeratosis, granular layer decreased or disappeared. Munro-abscess were seen in about 20% (6 / 30) cases.2 MIF staining results: MIF staining markedly presented in cytoplasm of epidermal keratinocytes and dermal layer inflammatory cells and vascular endothelial cells in psoriasis vulgaris,but expressed weakly in basal cell layer and prickle cell layer of health control. Results showed that MIF levels in the psoriatic lesions were significantly higher than health control, the difference was significant (P < 0.001).3 MMP-9 staining results: MMP-9 staining markedly presented in cytoplasm of epidermal keratinocytes and dermal layer infiltrating lymphocytes in psoriasis vulgaris,but expressed weakly in basal cell layer and prickle cell layer of health control. Results showed that MMP-9 levels in the psoriatic lesions were significantly higher than health control, the difference was significant (P <0.001).4 TNF-αstaining results: TNF-αstaining markedly presented in cytoplasm of epidermal keratinocytes and dermal papilla perivascular in psoriasis vulgaris,but expressed weakly in basal cell layer and prickle cell layer of health control. Results showed that TNF-αlevels in the psoriatic lesions were significantly higher than health control, the difference was significant P <0.001).5 MIF and MMP-9 expression: the expressions of MIF and MMP-9 in psoriatic lesions showed significantly positive correlation. (r = 0.987, P <0.01).6 MIF and TNF-αexpression: the expressions of MIF and TNF-αin psoriatic lesions showed significantly positive correlation. (r = 0.856, P <0.01).7 MMP-9 and TNF-αexpression: the expressions of MMP-9 and TNF-αin psoriatic lesions showed significantly positive correlation. (r = 0.843, P <0.01).8 There was no obvious difference in MIF expression in the sex,age, course and stage in psoriatic lesions. (P >0.05).Conclusions1 MIF was over expressed in psoriatic lesions, which suggested that it may be involved in the infiltration of chronic inflammatory cells. 2 MMP-9 was over expressed in psoriatic lesions suggested that may be involved in the formation of new blood vessels.3 TNF-αwas over expressed in psoriatic lesions ,which suggested that TNF-αmay be played an important role in the occurrence and development of psoriasis as a proinflammatory factor.4 The expression of MIF, MMP-9 and TNF-αin the psoriatic lesions are positively correlated each other which shows that they have the direct or indirect relationships in the development of psoriatic lesions.