Expression Of PPARγmRNA On Peripheral Blood Mononuclear Cells Of Psoriasis Vulgaris Patients

Objective：Psoriasis is one of the most common chronic inflammatoryskin disease characterized by exaggerated keratinocyte proliferation. Thisdisease is more common in young adults and it occurs frequently in winter.Psoriasis has three principal histological features:epidermal hyperplasia;dilated, prominent blood vessels in the dermis; and an inflammatory infiltrateof leucocytes, predominatly into the dermis. The clinical manifestations arewhite scales, film phenomenon and Auspitz sign.According to clinicalfeatures,it can be divided into four types:psoriasis vulgaris， psoriasisarthropathica, psoriasis pustulosa and erythrodermic psoriasis.The mostcommon type of psoriasis,accounting for90%of all cases, is psoriasis vulgaris.Awareness is increasing that psoriasis is not only a skin disease but alsoassociated with systemic disorders, including diabetes mellitus, metabolicsyndrome, depression, and cancer.The aetiology and pathogenesis of psoriasis remain enigmatic. It is likely thatthere is an interplay between genetic and environmental factors.Psoriasis is aninflammatory T cell-mediated disease characterized by epidermal hyperplasiaand parakeratosis. T-cells play a important role, and the cytokine pattern isskewed towards T helper type1cells, characterized by the production ofinterleukin2and interferon-γ.Elevatde levels of proinflammatorycytokines,including TNF-α, are found in psoriatic lesions. In recent years,studies have shown that PPAR γ is associated with the pathogenesis ofpsoriasis and the metabolic syndrome. PPAR γ is the members of thesuperfamily of transcription factors, originally was thought to regulat sugarmetabolism, energy metabolism, fat differentiation, cell growth anddifferentiation, the present study suggests that the activation of PPAR γ haveanti-inflammatory effects in chronic inflammatory diseases. In recent years,studies have shown that PPAR γ ligands can decrease the inflammatoryresponse in inflammatory disease such as inflammatory boweldisease,rheumatoid arthritis and brondial asthma.Studies suggested that the expression of PPARγin psoriatic lesion was low,butits expression is not clear in the blood. We applied the real time fluorescencequantitative reverse transcription-polymerase chain reaction (RT-PCR) todetect the expression of PPARγmRNA in the psoriasis vulgaris patient’speripheral blood, to analyzed difference in different stages and the relationshipbetween the expression of PPARγ with the PASI score value., and to learn therole of PPARγ in the pathogenesis of posriasis at the transcriptional level.Method：30patients of Psoriasis vulgaris were involved from thedepartment of dermatology in the second hospital of Hebei Medical University.Among them, there were17males and13females, mean age22.60士8.26years, the course of the disease was from3months to5years.Selection criteria of patient group:(1) Patients with psoriasis vulgarishave the feature of typical skin lesions and a clear diagnosis.(2) Not usedglucocorticoid or other drugs that could affect the immune system of the bodywithin1month before the experiment.(3) None of them accompanied withautoimmune diseases, allergic diseases or other serious chronic systemicdiseases.According to the disease stage,case group were divided into theprogressive stage group of16cases and stationary stage group of14cases.PASI score was evaluated by the same one according to psoriasis areaand severity. The control group involved20healthy persons withoutautoimmune diseases,allergic diseases and systemic disease. The gender andage were not statistically different between the two groups.Peripheral venous blood was obtained from the two groups. theexpressions of PPARγmRNA in peripheral blood mononuclear cells (PBMC)were detected by the RT-PCR. Using the SPSS13.0statistical software, all theexperiment data was tested by the normality test to clear the generaldistribution types. Non-normal distribution data was described as median[Md] and the comparison between groups used Wilcoxon test. When P <0.05, we think that it is as a statistical significance. The psoriasis PASI score valuewere non-mormal distribution by test. We used the variables rank correlationanalysis(Spearman method) to analyze the relationship between the expressionof the psoriasis PASI score. We used the variables rank correlationanalysis(Spearman method) to analyze the relationship between the expressionof PPARγ in the blood of case group and PASI score. P<0.05had statisticallysignificance.Results:1Expression of PPARγ in peripheral blood mononuclear cells of patients withpsoriasis vulgaris was significantly lower than that of normalcontrols(P<0.05).2The level of PPARγwas difference between progressive stage group andstationary stage group was not statistically significant(P>0.05).3PASI score was not correlated to the expression of PPARγ in peripheralblood mononuclear cells in patients with psoriasis vulgaris,showing acorrelation coefficient as0.35，P=0.06(P>0.05).4The expression of PPARγin the peripheral blood of the progressive stagegroup and PASI score had no correlation(r=0.37,P=0.17P>0.05); Theexpression of PPARγ in the peripheral blood of the stationary stage group andPASI score had no correlation(r=0.15,P=0.62P>0.05).Conclusisons:1The expression of PPARγ mRNA in patients with psoriasis vulgaris waslower than that in the control group.Meanwhile the expression of PPARγmRNA of the progressive stage group and that of the stationary stage grouphad no significant difference. Indicating that PPARγ may mediate thepathogenesis of psoriasis vulgaris, it may play an important role in themaintenance of psoriasis vulgaris.2There was no correlation between the expression level of PPARγ mRNA inpatients with psoriasis vulgaris with PASI score value, so the expression levelof PPARγ had no clear relevance with the psoriasis skin lesions area andseverity, it could not be an indicator for the evaluation of psoriasis vulgaris severity.