Pathogenic Mechanisms of Pulmonary Lymphangioleiomyomatosis

项目摘要/摘要 淋巴管肌瘤病(LAM)，以异常平滑肌结节状增殖为特征。 类细胞(LAM细胞)和肺囊肿是女性慢性阻塞性肺疾病发病率和死亡率的重要原因 结节性硬化症(TSC)或散发性LAM。LAM与基因有关 TSC1或TSC2失活。关键知识差距包括LAM结节内细胞的异质性， TSC2缺陷的LAM细胞的细胞来源，以及LAM以女性为主的机制。 肺间充质中TSC2(E6.5-E14.5)早期发育缺失导致结节性肺 成年期的病变，主要发生在雌性小鼠身上。这些增殖性结节由丢失的细胞组成。 TSC2以及野生型细胞，类似于人类LAM结节。结节中含有细胞，表达 平滑肌肉和黑素细胞谱系蛋白，人类LAM的标志。后来发育性缺失 TSC2(E13.5-P1)保留了肺血管，不会导致肺结节病变。 成人期。TSC2缺失的间充质细胞中存在代谢和线粒体缺陷 肺结节，与野生型对照比较。雌激素刺激这些TSC2缺失细胞的增殖， 但不是野生型细胞，并上调线粒体衍生的活性氧物种。这些和其他 初步数据导致了我们的中心假设：肺间充质亚群中mTORC1的过度激活 细胞导致雌激素依赖的结节样病变的增殖，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)用一种新的方法分析LAM的分子和细胞机制 新的自发性LAM样肺损害小鼠模型。高激活的mTORC1在血管紧张素转换酶激活中的作用 肺LAM样结节将使用药理学和遗传学方法进行检查。其影响 TSC2缺乏症对细胞代谢和线粒体功能的影响将首次在肺中得到解决 间充质来源的细胞可能是细胞异常生长的机制。LAM细胞的起源和 将研究肺外间充质细胞向LAM样结节募集的机制。 使用异种异种和同种异体移植模型。2)确定性别在促进以下方面的具体作用 肺间充质TSC2缺失小鼠LAM样结节的形成和发展。的角色 将通过改变雌激素活性或在体内研究肺LAM样病变中的雌激素 同时缺失ERα/Tsc2或ERβ/Tsc2及体外代谢谱、RNA-SEQ、CHIP-SEQ TSC2-空细胞与野生型细胞比较。该项目将通过填充知识产生很高的科学和临床影响 GAP对LAM女性患者具有翻译影响，并提供了一种新的临床前治疗模式。

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.