Uterine-specific genetic modification and lymphangioleiomyomatosis

描述(申请人提供)：淋巴管肌瘤病(LAM)是一种罕见的疾病，主要见于女性，其特征是肺实质内弥漫性间质浸润性非典型平滑肌细胞病变，导致呼吸道受限。这种疾病的病因尚不清楚，但被认为涉及激素调节，因为它通常出现在月经初潮和更年期之间。此外，LAM经常在结节性硬化症复合体(TSC)突变的患者中发现，这表明TSC的失活可能有助于其发展。我们正在通过有条件地删除和/或激活对正常分化和功能至关重要的候选基因来研究子宫发育和相关的病理学。我们通过结构性激活连环蛋白或表达结肠腺瘤性息肉病(APC)的截短等位基因，创造了子宫特异性肌瘤(肌瘤)小鼠，初步证据表明，肌瘤是血管出血和随后的肥厚性瘢痕形成的结果。米勒管来源的女性生殖道内器官(子宫、输卵管、宫颈和阴道的头部)是来自双潜能哺乳动物胚胎的唯一结构，这在男性中没有发现，这表明子宫的激素反应性间充质基质细胞可能是肺纤维化细胞的来源，并解释了LAM的女性特异性。我们推测，肺LAM可能是由子宫血管病变引起的，子宫血管病变允许子宫基质细胞进入血管内，随后这些细胞可以在肺内寄居和增殖。我们的子宫出血和肌瘤小鼠模型的肺组织学分析显示，纤维化的肺斑块与人类LAM相似，也是人类LAM的HMB45、Asma和Desmin阳性标记。我们建议进一步研究这一假说的具体目的如下：(1)确认肺病变中的细胞来自子宫；(2)确定外周血中是否可以检测到子宫间充质细胞；(3)测试肺病变中平滑肌细胞的激素反应性；(4)评估肺病变的标志物特征，以便与人类LAM进行比较。这些研究的结果将为继续研究LAM病变的触发因素和信号通路奠定基础，并为针对这些通路的治疗药物的临床前研究提供体内模型系统。

DESCRIPTION (provided by applicant): Lymphangioleiomyomatosis (LAM) is a rare disease primarily found in females and is characterized by a diffuse interstitial infiltrate of atypical smooth muscle cell lesions in the lung parenchyma resulting in airway restriction. The etiology of the disease is unknown but is thought to involve hormonal regulation because it usually presents between menarche and menopause. Additionally, LAM is often found in patients with mutations in tuberous sclerosis complex (TSC), suggesting that inactivation of TSC can contribute to its development. We are studying uterine development and associated pathologies by conditionally deleting and/or activating candidate genes in pathways critical for normal differentiation and function. We have created mice with uterine-specific leiomyomas (fibroids) by either constitutively activating ¿-catenin or by expressing a truncated allele of adenomatous polyposis coli (APC) and we have shown preliminary evidence that the leiomyomas develop as a result of vascular hemorrhaging and subsequent hypertrophic scarring. The Mullerian duct-derived internal female reproductive tract organs (uterus, oviduct, cervix, and cranial portion of the vagina) are the only structures from the bipotential mammalian embryo not found in males, suggesting that the hormonally responsive mesenchymal stromal cells of the uterus might be the source of the cells for pulmonary fibrosis and account for the female-specificity of LAM. We hypothesized that pulmonary LAM might be caused by uterine vascular pathologies that allow intravasation of uterine stromal cells that can subsequently lodge and proliferate in the lungs. Histological analysis of the lungs from our mouse models with uterine hemorrhaging and leiomyomas showed fibrotic lung plaques similar to that observed in human LAM that were also HMB45-, aSMA- and desmin-positive, markers for human LAM. We propose to investigate this hypothesis further with the following Specific Aims: (1) confirm that cells in the lung lesions are derived from the uterus, (2) determine whether uterine mesenchymal cells can be detected in peripheral blood, (3) test the hormone responsiveness of the smooth muscle cells in the lung lesions, and (4) assess the marker profile of lung lesions for comparison with human LAM. The results from these studies will lay the foundation for continued investigation of the triggers and signaling pathways involved in the development of the LAM lesions as well as provide an in vivo model system for preclinical studies of therapeutics targeting those pathways.