Pathogenic Mechanisms of Pulmonary Lymphangioleiomyomatosis

项目总结/摘要 淋巴管平滑肌瘤病（LAM），以异常平滑肌结节性增生为特征- 细胞（LAM细胞）和肺囊肿，是妇女发病率和死亡率的重要原因， 多发性硬化症（TSC）或散发性LAM。LAM与遗传相关 TSC 1或TSC 2的失活。关键的知识差距包括LAM结节内细胞的异质性， TSC 2缺陷LAM细胞的细胞起源，以及LAM女性优势的机制。 肺间质中Tsc 2（E6.5-E14.5）的早期发育缺失导致结节性肺结核， 成年期的病变，主要发生在雌性小鼠中。这些增生性结节由丢失的细胞组成 Tsc 2以及野生型细胞，类似于人LAM结节。结节含有表达 平滑肌和黑素细胞谱系蛋白，人LAM的标志。后期发育缺失 Tsc 2（E13.5-P1），保留肺血管，不会导致肺结节性病变， 成年代谢和线粒体缺陷存在于Tsc 2缺失的间充质细胞中， 肺结节，与野生型对照相比。雌激素刺激这些Tsc 2-null细胞的增殖， 而不是野生型细胞，并上调尿道衍生的活性氧。这些和其他 初步数据导致我们的中心假设：mTORC 1在肺间充质细胞亚群中过度活化， 细胞导致结节样病变的雌激素依赖性增殖，与代谢和 线粒体功能障碍、肺外细胞募集和肺破坏。 提出了两个具体的目标：1）使用一种分子生物学方法来剖析LAM的分子和细胞机制。 具有自发性LAM样肺病变的新型小鼠模型。过度活化的mTORC 1在乳腺癌中的作用 肺LAM样结节将使用药理学和遗传学方法进行检查。的影响 Tsc 2缺陷对细胞代谢和线粒体功能的影响将首次在肺中得到解决。 间充质来源的细胞作为异常细胞生长的潜在机制。LAM细胞的起源和 肺外间充质细胞向LAM样结节募集的机制将被研究 使用联体共生和同种异体移植模型。2)确定性别问题在促进两性平等方面的具体作用， 肺间质Tsc 2缺失小鼠中LAM样结节的形成和进展。的作用 将通过改变雌激素活性，或 同时缺失ERα/Tsc 2或ERβ/Tsc 2，并通过代谢谱、RNA-seq、ChIP-seq在体外检测 Tsc 2-null与野生型细胞。该项目将通过填补知识，具有较高的科学和临床影响 对LAM女性患者产生转化影响的差距，并提供新的临床前治疗模型。

Project Summary/Abstract Lymphangioleiomyomatosis (LAM), characterized by nodular proliferation of abnormal smooth muscle- like cells (LAM cells) and pulmonary cysts, is a significant cause of morbidity and mortality in women with Tuberous Sclerosis Complex (TSC) or with the sporadic form of LAM. LAM is associated with genetic inactivation of TSC1 or TSC2. Critical knowledge gaps include the heterogeneity of cells within LAM nodules, the cellular origin of TSC2-deficient LAM cells, and mechanisms underlying the female predominance of LAM. Early developmental deletion of Tsc2 (E6.5-E14.5) in lung mesenchyme resulted in nodular pulmonary lesions in adulthood, predominantly in female mice. These proliferative nodules are composed of cells with loss of Tsc2 as well as wild-type cells, resembling human LAM nodules. The nodules contain cells expressing smooth muscle and melanocyte lineage proteins, hallmarks of human LAM. Later developmental deletion of Tsc2 (E13.5-P1), sparing the pulmonary vasculature, does not result in pulmonary nodular lesions in adulthood. Metabolic and mitochondrial defects are present in Tsc2-null mesenchymal cells derived from the pulmonary nodules, compared with wild-type controls. Estrogen stimulates proliferation of these Tsc2-null cells, but not wild-type cells, and upregulates mitochondrially-derived reactive oxygen species. These and other preliminary data lead to our central hypothesis: hyperactivation of mTORC1 in subsets of lung mesenchymal cells leads to estrogen-dependent proliferation of nodular-like lesions, associated with metabolic and mitochondrial dysfunction, recruitment of extrapulmonary cells and lung destruction. Two specific aims are proposed: 1) To dissect the molecular and cellular mechanisms of LAM using a novel mouse model with spontaneous LAM-like lung lesions. The role of hyperactivated mTORC1 in the pulmonary LAM-like nodules will be examined using both pharmacologic and genetic approaches. The impact of Tsc2 deficiency on cellular metabolism and mitochondrial function will be addressed for the first time in lung mesenchyme-derived cells as a potential mechanism for the abnormal cell growth. The origin of LAM cells and the mechanisms of recruitment of extrapulmonary mesenchymal cells to LAM-like nodules will be examined using both parabiosis and allograft models. 2) To determine the specific role of gender in contributing to the formation and progression of LAM-like nodules in mice with lung mesenchymal Tsc2 deletion. The roles of estrogen in the pulmonary LAM-like lesions will be investigated in vivo by altering estrogen activity or simultaneous deletion of ERα/Tsc2 or ERβ/Tsc2 and in vitro by metabolic profiling, RNA-seq, ChIP-seq in Tsc2-null vs. wild-type cells. This project will have high scientific and clinical impact by filling knowledge gaps with translational impact for women with LAM and providing a new preclinical therapeutic model.