Neurogenic inflammation and psoriasiform dermatitis

描述（由申请人提供）：银屑病皮肤含有更多的神经纤维，感觉神经源性降钙素基因相关肽（CGRP）和P物质（SP）水平升高。有趣的是，一些病例报告显示，银屑病斑块在意外的皮肤去神经支配和随后的神经源性因子丧失后消退。这些结果暗示神经系统在维持和加剧银屑病表型中的作用；然而，神经在介导皮肤炎症和增生的细胞和分子机制中的作用和贡献仍然不清楚。我们小组最近的研究发现，在银屑病样皮炎的KC-Tie2小鼠模型中，皮肤神经纤维和神经源性SP和CGRP增加，为探索神经在银屑病发病机制中的作用提供了一个实验范例。手术切除进入KC-Tie2小鼠背侧皮肤的所有神经纤维后，从手术后1天(d)开始观察到CD11c+树突状细胞（dc）减少40%，随后7天棘层改善30%，10天CD4+ T细胞减少30%。这些结果依赖于SP和CGRP；在去神经支配的KC-Tie2皮肤中，SP和CGRP的重建阻止了表型的改善，而在有神经支配的KC-Tie2皮肤中，SP和CGRP的抑制以神经肽特异性的方式概括了实验去神经支配所得到的结果。在皮内注射肉毒杆菌毒素A（一种神经源性CGRP/SP抑制剂）后，观察到类似水平的改善。总之，这些结果确定了神经源性SP和CGRP是牛皮癣样皮肤炎症的关键介质，并提供了解释神经依赖性清除的病例和轶事报道的潜在机制，并为确定新的治疗途径提供了独特和创新的机会。为了确定受神经源性SP和CGRP影响的细胞靶点，以及用于指导KCs、dc和T细胞反应并转化为牛皮癣持续炎症和棘层的潜在机制，我们建议：(1)在体外用SP或CGRP刺激KCs、DCs或T细胞，定量测定在SP和CGRP药理学抑制剂存在/不存在的情况下，细胞增殖和分化、白细胞迁移、DC和T细胞源性细胞因子和kc源性白细胞化学引诱剂产生的变化；(2)利用T细胞缺陷小鼠和白喉毒素受体诱导的dc -贫小鼠与SP-和CGRP受体缺陷小鼠结合，利用转基因和皮肤移植策略的结合改变SP和CGRP对KCs和皮肤源性免疫细胞的直接影响，设计出区分皮肤特异性免疫调节反应的策略。从我们的研究中获得的信息将确定受神经源性SP和CGRP影响的细胞靶点，以及用于指导KCs， dc和T细胞反应的潜在机制，这些反应转化为牛皮癣的持续炎症和棘层。

DESCRIPTION (provided by applicant): Psoriatic skin contains more nerve fibers and increased levels of sensory nerve-derived calcitonin gene related peptide (CGRP) and substance P (SP). Interestingly, several case reports have demonstrated psoriatic plaque resolution following accidental skin denervation, and subsequent loss of nerve-derived factors. These results imply a role for the nervous system in maintaining and exacerbating the psoriasis phenotype; however the role and contribution of nerves to the cellular and molecular mechanisms mediating cutaneous inflammation and hyperplasia remains poorly defined. Recent work from our group has identified increases in cutaneous nerve fibers and nerve-derived SP and CGRP in the KC-Tie2 murine model of psoriasiform dermatitis providing an experimental paradigm to explore neural contributions to psoriasis pathogenesis. Following surgical elimination of all nerve fibers entering dorsal skin of KC-Tie2 mice, a 40% decrease in CD11c+ dendritic cells (DCs) was observed beginning 1 day (d) following surgery, followed by a 30% improvement in acanthosis by 7d and a 30% decrease in CD4+ T cells by 10d. These outcomes were SP and CGRP dependent; as reconstitution of SP and CGRP in denervated KC-Tie2 skin prevented phenotype improvement and inhibition of SP and CGRP in innervated KC-Tie2 skin recapitulated the findings elicited by experimental denervation in a neuropeptide specific manner. Similar levels of improvement were observed following one intradermal injection of Botulinum toxin A, a well characterized inhibitor of nerve-derived CGRP/SP. Together these results identify nerve-derived SP and CGRP as critical mediators of psoriasisform skin inflammation, and offer a potential mechanism explaining case and anecdotal reports of nerve-dependent clearing, and provide a unique and innovative opportunity for identifying new therapeutic avenues. To identify the cellular targets affected by nerve-derived SP and CGRP as well as the potential mechanism(s) used to direct KCs, DCs and T cell response that translates to sustaining inflammation and acanthosis in psoriasis, we propose to: (1) stimulate KCs, DCs or T cells in vitro with SP or CGRP and quantitate changes in cell proliferation and differentiation, leukocyte migration and the production of DC- and T cell-derived cytokines and KC-derived leukocyte chemoattractants, in the presence/absence of pharmacological inhibitors of SP and CGRP; and (2) alter SP and CGRP direct effects on KCs and skin- derived immune cells using a combination of transgenic and skin transplant strategies designed to compartmentalize skin specific immunomodulatory responses utilizing T cell-deficient mice and diphtheria toxin receptor inducible DC-depleted mice coupled to SP- and CGRP-receptor deficient mice. The information gained from our studies will identify the cellular targets affecte by nerve-derived SP and CGRP as well as the potential mechanism(s) used to direct KCs, DCs and T cell response that translates to sustaining inflammation and acanthosis in psoriasis.