cpdm: Cloning a Gene That Regulates Eosinophil Function

描述(申请人提供)：我们最初的资助申请的目标是识别自发的、常染色体的、隐性的小鼠突变“慢性增殖性皮炎”(原始突变位点代码：CPDM)的基因。这是完成的，并被确认为夏平。突变的Sharpin基因的功能与cpdm表型有关，人们对此知之甚少。携带Sharpin基因自发突变的小鼠显示，Sharpin基因在次级淋巴器官的正常发育中起着关键作用，它的缺失会导致嗜酸性粒细胞增多，实质器官中有嗜酸性粒细胞和其他炎性细胞聚集。这些突变小鼠发展成一种严重的银屑病样皮肤病，其特征是持续的、显著的表皮增生，伴随着角质形成细胞的凋亡、嗜酸性粒细胞的聚集，以及皮肤肥大细胞、巨噬细胞和其他炎症细胞的同时增加。炎症改变在其他器官也很明显，包括关节、肺、上胃肠道和肝脏。这里提出的实验将定义Sharpin的功能，并确定该基因如何调节正常的免疫系统发育，并控制皮肤和其他器官的炎症。我们将在时间进程研究中利用基因阵列和网络分析软件来确定涉及的分子事件。将Sharpin转基因小鼠与我们资料库中提供的各种启动子-Cre重组酶基因工程小鼠杂交，将使我们能够确定无处不在的和器官或细胞特异性的Sharpin失活的影响。细胞转染研究和ChlP-on-Chip方法将识别靶点，使我们能够确定Sharpin在哪些基因/蛋白质网络中发挥作用。这些方法将确定由于Sharpin基因失活而导致的皮肤和免疫系统异常的暂时发病机制，并确定该基因在哪个分子途径中发挥作用(S)。慢性增殖性皮炎突变小鼠是定义免疫系统发育和牛皮癣样皮炎的一种新的疾病机制的有价值的工具。与公共卫生相关：我们确定了一种基因，当突变时，会导致严重的全身性炎症性疾病，这种疾病与几种人类疾病的病理变化相同。我们将确定小鼠疾病的分子发病机制。很可能人类存在同源疾病，从小鼠模型中学到的知识将有助于诊断测试和治疗开发。

DESCRIPTION (provided by applicant): The objective of our original grant application was to identify the gene underlying the spontaneous, autosomal, recessive mouse mutation named "chronic proliferative dermatitis" (original mutant locus symbol: cpdm). This was accomplished and identified as Sharpin. The function of the mutated Sharpin gene, responsible for the cpdm phenotype, is poorly understood. Mice carrying spontaneous mutations in Sharpin reveal that it plays a key role in normal development of secondary lymphoid organs and its absence leads to eosinophilia with accumulations of eosinophils and other inflammatory cells in parenchymous organs. These mutant mice develop a severe psoriasiform skin disease characterized by persistent, marked, epidermal hyperplasia, accompanied by apoptotic keratinocytes, accumulation of eosinophils, and concurrent increases in cutaneous mast cells, macrophages, and other inflammatory cells. Inflammatory changes are also evident in other organs including joints, lungs, upper gastrointestinal tract, and liver. Experiments proposed here will define the function of Sharpin and determine how this gene modulates normal immune system development, and controls inflammation in the skin and other organs. We will utilize gene arrays and network analysis software in time course studies to determine the molecular events involved. Crossing a floxed Sharpin transgenic mouse with various promoter-Cre recombinase genetically engineered mice available in our repository will allow us to determine the effects of ubiquitous and organ- or cell-specific inactivation of Sharpin. Cell transfection studies and chlP-on-chip approaches will identify targets allowing us to determine in which gene/protein networks Sharpin functions. These approaches will define the temporal pathogenesis of skin and immune system abnormalities due to inactivation of the Sharpin gene and determine in which molecular pathway(s) this gene functions. The chronic proliferative dermatitis mutant mouse is a valuable tool to define what appears to be a novel disease mechanism for immune system development and psoriasiform dermatitis. Relevance to Public Health: We identified a gene that when mutated, results in severe systemic inflammatory disease that shares pathologic changes with several human diseases. We will define the molecular pathogenesis of the mouse disease. It is likely that a homologous condition exists in humans and knowledge learned from the mouse model will aid in diagnostic test and therapy development.