Role of Gene Expression in Interstitial Cystitis

描述（由申请人提供）：我们研究的长期目标是使用自然发生的猫科动物模型充分了解间质性膀胱炎（IC）的病因，IC是一种影响人类和家猫的特发性慢性疼痛综合征，以开发有效的治疗方法。研究发现，产前和产后早期的不良经历可能导致应激反应系统的“重新编程”，假设这种应激反应系统使易感个体在以后的生活中易患各种疾病。此类事件发生在许多患有IC共病疾病的患者中。此外，IC猫的肾上腺皮质异常可能是早期不良经历的结果，使这些猫成为IC的重要自然发生模型。本提案中待检验的假设是，不良经历导致DNA甲基化改变，这是一种表观遗传变化，导致基因表达改变，并增加了在FIC猫和IC人中观察到的膀胱和神经内分泌异常发展的易感性。本研究的具体目标是：1）采用快速消减杂交技术，研究正常猫和FIC猫的尿胸腺和肾上腺皮质基因的差异表达，并采用RT-PCR技术检测三个候选基因的差异表达：糖皮质激素受体（GR）、促肾上腺皮质激素受体（ACTHR）和促肾上腺皮质激素释放因子（CRF），2）通过使用DNA甲基接受能力比较整体甲基化模式来探索DNA甲基化作为改变基因表达的机制的作用，以及使用减法杂交鉴定的基因的5'调控区中的DNA甲基化模式，以及GR、ACTHR和CRF基因的5'调控区中的DNA甲基化模式。在自然发生的IC模型中识别基因表达的改变模式可能会显著影响我们对IC病因的理解，这自然会导致治疗这种疾病的新方法，包括迄今为止未考虑用于这些患者的药物测试。更重要的是，确定这种疾病机制的存在可能会导致孕妇和儿童的公共卫生建议发生重大变化，以避免可能导致基因表达模式发生这种有害变化的环境条件。鉴于IC患者中常见的共病疾病，这些建议可能与目前被归为“医学上无法解释的综合征”的整个疾病类别有关。

DESCRIPTION (provided by applicant): The long term goal of our research is to use a naturally occurring feline model to gain a sufficient understanding of the causes of interstitial cystitis (IC), an idiopathic chronic pain syndrome affecting humans and domestic cats, to permit development of effective therapies. Converging lines of research have found that adverse experience during the prenatal and early postnatal periods can result in a "re-programming" of the stress response system that is hypothesized to predispose susceptible individuals to a variety of diseases in later life. Such events have occurred in many patients with disorders co-morbid with IC. Moreover, an adrenocortical abnormality in cats with IC likely results from early adverse experience, making these cats an important naturally occurring model of IC. The hypothesis to be tested in this proposal is that adverse experience leads to alterations in DNA methylation, an epigenetic change that results in altered gene expression and increases susceptibility for the development of the bladder and neuroendocrine abnormalities observed in cats with FIC and humans with IC. The specific objectives of this proposal are to: 1) investigate the differential expression of genes in urothelium and adrenal cortex between normal cats and cats with FIC using a general screening strategy called rapid subtraction hybridization, and to use RT-PCR to examine differential expression three candidate genes: glucocorticoid receptor (GR), ACTH receptor (ACTHR) and corticotropin releasing factor (CRF), 2) to explore the role of DNA methylation as a mechanism of altered gene expression by comparing global methylation patterns using DNA methyl-acceptance capacity, and DNA methylation patterns in the 5' regulatory regions of genes identified using subtraction hybridization, and of the GR, ACTHR, and CRF genes. Identifying altered patterns of gene expression in a naturally occurring model of IC could significantly affect our understanding of the causes of IC, which naturally will lead to novel approaches to treatment of this condition, including tests of drugs not heretofore considered for use in these patients. More importantly, identification of the presence of this disease mechanism could lead to significant changes in public health recommendations for pregnant women and children to avoid environmental circumstances that could lead to such detrimental changes in gene expression patterns. Given the common occurrence of co-morbid disorders in patients with IC, these recommendations may be pertinent to the entire category of disorders currently lumped together as "medically unexplained syndromes".