开玄解毒核心方通过TrkA受体调节CGRP表达与树突状细胞活化改善银屑病样炎症的机制OA

Objective:To investigate the ameliorative effects and mechanisms of Kaixuan Jiedu core prescription(KXJD)on neuroimmunological inflammation in imiquimod(IMQ)-induced psoriasis-like mice.Methods:A total of 24 C57BL/6J mice were randomly divided into four groups(n=6):Normal,model,KXJD,and tropomyosin receptor kinase A(TrkA)inhibitor GW441756 groups.The mice in the model,KXJD,and GW441756 groups were topically treated with 5%IMQ cream(62.5 mg·d-1)on the back to induce psoriasis-like inflammation.The KXJD group received KXJD by gavage(30.42 g·kg-1),the GW441756 group received intraperitoneal injection of GW441756(10 mg·kg-1),and the normal and model groups received an equal volume of normal saline by gavage,with continuous intervention for 5 days.The severity of skin lesions was evaluated using the psoriasis area and severity index(PASI).Hematoxylin-eosin(HE)staining was used to measure epidermal thickness and observe pathological changes in the lesioned skin.Immunohistochemistry was employed to detect the expression of proliferating cell nuclear antigen(Ki67)and interleukin-17A(IL-17A)in the lesioned skin.Enzyme-linked immunosorbent assay(ELISA)was used to quantify the levels of interleukin-23(IL-23)and calcitonin gene-related peptide(CGRP)in the lesioned tissues.Western blot was used to detect the expression of TrkA and phosphorylated TrkA(p-TrkA).Immunofluorescence assay was performed to detect the expression of TrkA receptor,protein gene product 9.5(PGP9.5),cluster of differentiation 11c(CD11c),and CGRP in the lesions.Flow cytometry was used to detect the activation of splenic dendritic cells(DCs).Results:Compared with the normal group,the model group exhibited typical psoriasis-like inflammation,characterized by erythema,infiltration and scaling,with histopathological findings of epidermal hyperkeratosis and acanthosis.The model group showed significantly increased expression of Ki67,IL-17A,IL-23 and p-TrkA(P<0.05,P<0.01),increased fluorescence intensity of CD11c,and significantly decreased CGRP expression(P<0.05).The splenic DC activation was significantly enhanced,as indicated by the increased mean fluorescence intensity(MFI)of CD86(P<0.05).Compared with the model group,both the KXJD and GW441756 groups showed amelioration of the psoriasis-like skin inflammation,with significantly down-regulated expression of IL-17A,IL-23 and p-TrkA(P<0.05,P<0.01),significantly up-regulated expression of CGRP(P<0.01),reduced CD11c+DC infiltration,and restored splenic DC activation balance(down-regulated CD86 MFI and up-regulated CD80 and CD40 MFI).Furthermore,the inhibitory effect of KXJD on Ki67 was significantly superior to that of the GW441756 group(P<0.01).Conclusion:KXJD may alleviate IMQ-induced psoriasis-like inflammation in mice by targeting and inhibiting TrkA receptor phosphorylation,regulating CGRP expression in the lesions,and ameliorating aberrant activation of dendritic cells,while also significantly inhibiting keratinocyte proliferation.