CUTANEOUS BIOLOGY OF NITRIC OXIDE

一氧化氮（NO）是一种重要的信使和效应物 分子在皮肤生理学和稳态中作用以及NO水平的改变 在皮肤上引起疾病。该提案的目的是确定 NO在皮肤中的作用，重点是确定功能效应 这种气体。 已经证明人而非鼠的角质形成细胞具有 表达诱导型一氧化氮合酶（iNOS）的能力， 老鼠和人之间的这种关键差异可以解释为什么 小鼠不会出现类似于在 人类将NOS靶向皮肤模拟物的转基因小鼠， 在这里显示出在人类条件下发现的表型。常规 在小鼠中，iNOS在朗格汉斯细胞（LC）中表达。NO也是由 LC样细胞系XS-52。LC中产生的NO可能影响LC功能， 由于NO可自由扩散穿过细胞膜，因此它具有 影响表皮中的相邻细胞。一氧化氮对黑素细胞的毒性作用 和角质形成细胞提示NO可能是一种效应分子， 皮肤状况，包括炎症后色素沉着不足， 白癜风，移植物抗宿主病（GVH），硬皮病和通常致命的 中毒性表皮坏死松解症（TEN）。 在拟定研究中，将评价纯化LC的生产 采用RT-PCR检测iNOS的表达，采用Griess反应检测NO的表达， 放射性L-精氨酸转化为瓜氨酸。的影响 将检测NOS调节中的选定细胞因子。的影响 将研究NO对XS-52细胞本身的影响。NO-的作用机制 黑素细胞和角质形成细胞的诱导杀伤将在共- 用XS-52细胞和通过与NO供体孵育进行培养实验。 其中NOS表达靶向于表皮的转基因小鼠具有 产生，表型发展为白色毛发和组织病理学， 硬皮病将对这些动物进行进一步表征。小鼠表达 将产生在诱导型启动子控制下的NOS。的 将测试转基因小鼠作为色素沉着疾病的模型， 抗原呈递、硬皮病、TEN和GVH。这些结果具有 可能导致新的治疗策略，用于治疗 人类疾病

It is proposed that nitric oxide (NO) is a critical messenger and effector molecule in skin physiology and homeostasis and that altered levels of NO in the skin cause disease. The goal of the proposal is to define the role of NO in skin with an emphasis towards determining the functional effects of this gas. Human, but not murine, keratinocytes have been demonstrated to have the capacity to express inducible form of nitric oxide synthase (iNOS) and produce NO. This critical difference between mice and men may explain why mice do not develop cutaneous eruptions analogous to those found in humans. Transgenic mice in which NOS is targeted to the skin mimic are shown here to develop phenotype found in human conditions. In conventional mice, iNOS is expressed in Langerhans cells (LC). NO is also produced by the LC-like cell line XS-52. NO produced in LC may affect LC function and, as NO is freely diffusible across cell membranes, it has the capacity to affect adjacent cells in the epidermis. Toxic effects of NO on melanocytes and keratinocytes suggest that NO may be an effector molecules in a number of skin conditions, including post-inflammatory hypo-pigmentation, vitiligo, graft versus host disease (GVH), scleroderma and the often fatal process, toxic epidermal necrolysis (TEN). In the proposed studies, purified LC will be evaluated for the production of iNOS using RT-PCR and measurement of NO using the Griess reaction and the conversion of radioactive L-arginine to citrulline. The effects of selected cytokines in the regulation of NOS will be examined. The effects of NO on XS-52 cells themselves will be studied. The mechanism of NO- induced killing of melanocytes and keratinocytes will be examined in co- culture experiments with XS-52 cells and via incubation with NO donors. Transgenic mice in which NOS expression is targeted to the epidermis have been produced, phenotypically develop white hair and histopathologically, scleroderma. These animals will be characterized further. Mice expressing NOS under the control of an inducible promoter will be generated. The transgenic mice will be tested as models for disorders of pigmentation, antigen presentation, scleroderma, TEN and GVH. These results have the potential to lead to novel therapeutic strategies for the treatment of human disease.