The Expression Of Cortistatin In Psoriasis And The Effect Of Exogenous Cortistation On A Proliferation Model Of EGF-induced HaCaT Cell

ObjectiveTo investigate the roles of cortistatin (CST) in the pathogenesis of psoriasis vulgaris by determining the expression of CST in the serum and lesion of patients, and the effect on proliferation in EGF-induced HaCaT cells by exogenous CST.Methods1.CST levels in the serum of 72 psoriasis vulgaris and 76 normal controls were detected by ELISA assay,while the expression in the lesion of 14 psoriasis vulgaris (from the 72 patient) and 14 normal skin detected by immunohistochemistry.2. HaCaT cells were seeded to 6-well plates at a density of 1×106/well for 24h, and then the expression of CST protein in HaCaT cell line was detected by immunocytochemistry, while CST mRNA was identified by semi-quantitive reverse transcription-polymerase chain reaction(RT-PCR).3. HaCaT cells were seeded to 96-well plates at a density of 5,000/well, let to plate,changed for RPMI-1640 medium containing 10 ng/ml EGF, HaCaT cells with 10 ng/ml EGF were treated with different concentrations of exogenous CST (10-9-10-6M) for 24 h, the proliferation was determined by MTT assay, repeated three times,an optimal EGF concentration was chosen for further study.4. Immunocytochemistry assay was chosed to investigate the expression of proliferation index Ki-67 among the following three groups: HaCaT cell without CST and EGF group (blank), HaCaT cell with lOng/ml EGF group (control) and HaCaT cell with lOng/ml EGF and 10-6M CST group (experimental group).5. Second messenger cAMP in above three groups were detected by Employed Enzyme-linked immunosorbent assay (ELISA)Results1. CST level was significantly lower than normal control both in the serum and in the skin (P<0.05),but there was no significant correlation between the serum CST level and the PASI (P>0.05).2.CST protein was expressed in the cytoplasm of HaCaT cell, and CST mRNA (173bp) was expressed in HaCaT cell line.3. All concentrations of CST (10-9-10-6M) could inhibit the proliferation of HaCaT cell containing 10ng/ml EGF in the medium in a concentration dependent style and at 10-6M there was the best inhibit effect with an inbibition rate of 54.62%(P<0.05).4. Ki-67 had a higher express in lOng/ml EGF-group (control) than non-EGF-CST group (blank), while in the EGF - CST group (experimental group), the express of Ki-67 was inclined again(P<0.05).5. There were a positive tendency of second messager cAMP with the change of Ki-67(P<0.05).Conclusion(1)The lower expression of CST in the serum and lesion of psoriasis vulgaris than normal control may be involved in the pathogenesis of psoriasis.(2) The proliferation of EGF-induced HaCaT cell can be inhibited by exogenous CST.