鸦胆子苦醇基于寒凉箍围法对银屑病分化过程的研究

The research for psoriasis mechanism has caused the wild attention in the field of dermatology. The project is found in the early stage of traditional Chinese medicine Brusatol treatment psoriasis vulgaris may be through microRNA let-7b targeted IL13 in prophase study. On the basis of scientific hypothesis is proposed: Brusatol treatment may be based on the specificity with psoriasis vulgaris interference Nrf2 / HO - 1 signaling pathways, promote excessive proliferation of cutin cell apoptosis to achieve purpose. This project combined with transgenic mouse model specificity expression of let-7b in skin, using the Imiquimod induced animal models of psoriasis, combined with syndrome differentiation of traditional Chinese medicine, screening the best drug concentration of Brusatol. Exploring the Brusatol affect related signaling pathways through let-7b to regulate cell differentiation process, as well as regulating Nrf2 / HO- 1 signaling pathway to promote cell apoptosis; Using molecular cloning and biology technology to detect the let-7b, IL-13 and related signal factor expression in RNA and protein levels; Applying the drug of DRB (Nrf2 inhibitors) to save experiment, observation of Nrf2 - ARE signaling pathways, clarify its mechanism and drug targets for the treatment of psoriasis. The project is made up for the inadequacy of traditional Chinese medicine external treatment, and from gene - protein - cytokines -- signaling pathways of psoriasis treatment mechanism in further study. It provides new theoretical and experimental basis for clinical prevention and treatment of psoriasis of traditional Chinese medicine.

银屑病发病机制一直是皮肤科研究的重点。本项目在前期发现鸦胆子苦醇治疗寻常型银屑病可能是通过作用microRNA let-7b并靶向IL13的基础上，提出科学假说：鸦胆子苦醇治疗寻常型银屑病可能是在此基础上特异性干扰Nrf2/HO-1信号通路，促进过度增殖的角质细胞凋亡来达到目的的。本研究选取过表达let-7b转基因小鼠诱发银屑病动物模型，结合中医辨证，从体内外实验验证鸦胆子苦醇通过let-7b影响相关信号通路来调控角质细胞分化过程，同时调控Nrf2/HO-1信号通路来促进角质细胞凋亡；在RNA和蛋白水平上检测let-7b、IL-13等相关信号因子表达；利用Nrf2抑制剂DRB进行挽救实验，观察Nrf2-ARE信号通路，明确其治疗银屑病的机制和药物作用靶点。该项目弥补了传统中医外治的不足，运用现代科学研究思路系统的为中医药防治银屑病提供新的理论和实验依据，对其防治具有较大意义。

银屑病易诊难治。鸦胆子作为“寒凉箍围药”的经典代表药用于银屑病治疗，但疗效机制不清。本课题致力于探索中药单体成分鸦胆子苦醇（BR）在银屑病中的机制和治疗效果。.课题首先在体外人永生化角质形成细胞（HaCaT）中筛选出BR最佳使用浓度，证实BR虽不能调控细胞凋亡，但能够抑制细胞活力和细胞增殖，并促进细胞分化。体内利用咪喹莫特（IMQ）诱导的银屑病样小鼠动物模型，围绕抗增殖和抗炎角度出发，观察到BR减缓IMQ诱导银屑病样动物模型，结果表明BR能够改善IMQ诱导的银屑病样皮损症状，并且改善皮损组织中棘细胞层增厚、角化过度伴角化不全、血管扩张等现象，为银屑病治疗方案提供新的参考依据。本项目首次从中成药物角度出发，探索其中药单体鸦胆子苦醇对microRNA let-7b的影响，体外明确了let-7b促进角质形成细胞分化过程，体内成功构建皮肤角质形成细胞特异性let-7b过表达的转基因小鼠，证实let-7b靶向IL-6从而抑制ERK信号通路，最终影响角质形成细胞分化过程来调节小鼠皮肤银屑病的发生发展。不仅如此，课题还发现利用ERK抑制剂（PD98059）或Nrf2抑制剂（DRB）处理银屑病样皮损可减缓IMQ诱导的病样症状，这为临床治疗提供有力的理论和实践依据。最后，课题还进行了部分实验扩展，建立肿瘤坏死因子-α（TNF-α）诱导的HaCaT细胞炎症模型，围绕抗增殖和抗炎角度出发，从体外探讨了BR对银屑病样细胞模型的作用效果，并初步阐明了鸦胆子苦醇可以通过干预NF-κB信号通路的活化从而降低炎性介质的产生，为后续在银屑病炎症进程中探索鸦胆子苦醇对炎症和免疫系统的影响奠定了基础。.本课题的研究成果，不仅丰富了银屑病治疗的“寒凉箍围法”中医理论，还为银屑病治疗提供了科学见解和机制研究，为下一步提高疗效打下了基础。