IDENTIFICATION AND PRECLINICAL EVALUATION OF NOVEL THERAPEUTIC APPROACHES TO DYSKERATOSIS CONGENITA

项目总结/摘要 罕见疾病先天性角化不良（DC）是由遗传缺陷引起的， 端粒，它是保护染色体末端的结构。端粒提前缩短 导致广泛的器官病理学，包括骨髓衰竭、肺纤维化瘢痕形成（肺 纤维化）和肝（肝硬化）和胃肠道疾病。骨髓移植可以 然而，成功地解决了骨髓衰竭，但其他病理没有得到有效治疗。在研究资助的 一项NIH R21基金，主要研究人员最近证明，肠道病理学涉及丧失 通过称为Wnt的细胞间通讯途径正常支持干细胞功能， 恢复Wnt通路信号传导（包括锂）可以改善这种病理。在此，我们建议 研究肺和肝病理学，特别是确定Wnt激活剂是否对这些组织有益 如在肠中观察到的。我们还将广泛研究其他受影响的途径， 治疗干预的要点。我们将使用人类诱导多能干细胞（iPSC）和基因组 编辑产生关键的肺和肝细胞，可以在培养中研究，沿着端粒酶缺陷 小鼠模型，研究这些机制，并测试新的治疗方法，重点是使用 FDA批准的药物。具体目标是： 1.表征人DC iPSC衍生的培养的II型肺泡上皮干细胞中的缺陷，并测试 药理学操作的能力旨在逆转改变的途径以改善这些缺陷。 2.表征人DC iPSC衍生的培养肝细胞和星状细胞中的缺陷，并测试 药理学操作的能力，旨在逆转改变的途径，以改善这些缺陷。 3.使用小鼠模型来解决药理学操作拯救人DC突变体的功效 iPSC衍生的组织在体内的情况下。这将包括测定最低血清锂 浓度，将拯救移植到小鼠体内的人体组织，并测试锂和其他小 分子来拯救由端粒功能障碍驱动的肺纤维化和肝硬化的小鼠模型。

Project Summary/Abstract The rare disease dyskeratosis congenita (DC) is caused by genetic deficiencies in the maintenance of telomeres, which are the structures that protect the ends of chromosomes. Premature telomere shortening leads to widespread organ pathology, including bone marrow failure, fibrotic scarring of the lungs (pulmonary fibrosis) and liver (hepatic cirrhosis), and gastrointestinal disorders. Bone marrow transplantation can successfully address marrow failure, but other pathologies are not treated effectively. In studies funded by an NIH R21 grant, the principal investigators demonstrated recently that intestinal pathology involves loss of normal support of stem cell function by an intercellular communication pathway called Wnt, and that drugs that restore Wnt pathway signaling (including lithium) can ameliorate this pathology. Here we propose to investigate lung and liver pathology, in particular to determine if Wnt activators are beneficial in these tissues as was observed in the intestine. We will also broadly investigate other affected pathways that might provide points of therapeutic intervention. We will use human induced pluripotent stem cells (iPSCs) and genome editing to generate key lung and liver cells that can be studied in culture, along with telomerase deficient mouse models, to investigate these mechanisms and test new therapeutic approaches focused on using existing FDA-approved drugs. The specific aims are: 1. Characterize defects in human DC iPSC-derived cultured type II alveolar epithelial stem cells, and test the capacity of pharmacologic manipulations aimed reversing the altered pathways to ameliorate these defects. 2. Characterize defects in human DC iPSC-derived cultured hepatocytes and stellate cells, and test the capacity of pharmacologic manipulations aimed at reversing the altered pathways to ameliorate these defects. 3. Use mouse models to address the efficacy of pharmacologic manipulations to rescue human DC mutant iPSC-derived tissues in an in vivo context. This will include determination of the minimum serum lithium concentration that will rescue human tissues transplanted into mice, and tests of lithium and other small molecules to rescue mouse models of pulmonary fibrosis and cirrhosis driven by telomere dysfunction.