The Roles Of Notch Pathway On The Lesions Of Patients With Psoriasis Vulgaris And The Intervention Effects Of Longdanxiegan Decoction

Objective:1.To investigate the effect of Notch signaling pathway on the proliferation and differentiation of HaCaT cells(human immortalized keratinocyte cell lines);2.To analyze how does the Notch pathway involved in psoriasis;3.To evaluate the effect of Longdan Xiegan Decoction on the expression of Notch1,Jagged 1 and Hes-1 in guinea pig psoriasis-like lesions.Methods:1.The effects of Notch signaling activator(Jagged 1-Fc fusion protein)and Notch signaling pathway inhibitor(DAPT)on HaCaT cells were detected by MTT assay,flow cytometry and Western blot.Proliferation,apoptosis and differentiation.2.The expression of Notch 1,Jagged 1 and Hes-1 mRNA and protein in skin tissues of patients with psoriasis were detected by real-time fluorescence quantitative RT-PCR and Western blot.3.Select 80 guinea pigs,the model of psoriasis-like pathological changes was made by using the 5%propranolol emulsion.The guinea pigs in the control group were divided into two groups:the blank group,the model group,the western medicine control group,the drug control group and the Longdan Xiegan decoction group,the middle and high dose treatment group.The Baker score and inflammatory cell infiltration were observed by HE staining.The expression of Notch 1,Jagged 1 and Hes-1 in the cells was detected by immunohistochemistry.Results:1.MTT results showed that,the absorbency in Jaggedl-FC treated group was much more than that of the control group(P<0.05),indicating that the Notch pathway can promote cell proliferation.Results of flow cytometry showed that the apoptosis rate of the Jaggedl-Fc treated group was 4.76�1.13,which was significantly decreased compared to the control group(13.69�2.05)(P<0.01).The apoptosis rate of the DAPT treated group was 26.87�3.18,which was much more than the control group.The results indicates that activating of Notch pathway can significantly inhibit the apoptosis of HaCaT cells,but interdict this pathway present a reverse result.Western blot results showed that the Jagged 1-Fc significantly promoted the expression of Bcl-2 protein,and inhibited the expression of Bax protein as well as Keratinl and Involucrin.However,the DAPT treated group presented a reverse result.2.The mRNA level and protein level of Notchl,Jaggedl and Hes-1 were much higher in patients than normal control,there were significant differences between them(P<0.05).These results suggests that the Notch pathway was associated with the psoriasis.3.There were significant difference of the Baker score and the inflammatory cells infiltration score between the normal group and other groups,indicating that the model was successfully established.Both of the Baker score and the inflammatory cells infiltration were much higher in MTX group and middle dose group than that of control group(P<0.05).The uncompleted cornification and the excessive cornification alleviated in the middle dose group.Immumohistochemical staining results showed that the expression levels of Notchl,jaggedl and Hes-1 were much higher in model group than that of other groups.The expression level of these three proteins were similar in longdanxiegan decoction middle dosage group and Western medicine group,which were much higher than that of high dose group?low dose group and medicine control group.Conclusion:1.Notch signaling pathway is involved in the proliferation and differentiation of HaCaT cells.Activation of Notch signaling pathway can promote the proliferation of HaCaT cells and inhibit the apoptosis and differentiation of HaCaT cells.In contrast,blocking Notch signaling pathway can inhibit the proliferation of HaCaT cells and promote the apoptosis and differentiation of HaCaT cells.2.Notch signaling pathway involved in HaCaT cell apoptosis may be related to the regulation of Bcl-2 and Bax protein expression,Notch signaling pathway involved in HaCaT cell differentiation may be related to the regulation of Keratinl and Involucrin protein expression.3.The Notch signaling pathway is up-regulated in the skin tissue of patients with psoriasis,and the activation of Notch signaling pathway is closely related to the occurrence of psoriasis.4.The middle dose Longdan Xiegan Decoction(4.5g/kg)is better for the treatment of psoriasis,which may be through the regulation of Notchl,Jaggedl and Hes-1 expression of microvascular inhibition to achieve the treatment of psoriasis purpose.