Germline mutations of PTPN11 (SHP2) in the stem cell microenvironment

项目摘要 努南综合征(NS)，一种以先天性心脏病为特征的发育障碍，畸形 面部结构、身材矮小和智力低下是由相关基因的胚系突变引起的 在RAS信号通路中。患有NS的患者患白血病的风险增加。这个 白血病发生的潜在机制尚不完全清楚。NS主要(&gt；50%)关联 蛋白酪氨酸磷酸酶PTPN11(SHP2)和NS的生殖系杂合激活突变 PTPN11基因突变的患者预后最差。我们实验室和其他实验室的研究已经 证实了造血细胞固有的PTPN11突变在NS发病机制中的因果作用 相关性白血病。值得注意的是，在上一个资助期，我们发现PTPN11激活突变 (E76K或D61G)在骨髓基质中，特别是表达巢蛋白的细胞和表达巢蛋白的细胞。 来源的间充质干细胞和骨祖细胞对发育做出了重要贡献。 血液系统恶性肿瘤在小鼠模型中的进展。然而，我们对这种影响的理解 PTPN11疾病在骨髓微环境中的突变仍不完全。我们最近的试点数据表明， PTPN11激活周围神经系统(PNS)和其他神经脊衍生后代的突变 在骨髓基质中，神经脊特异性PTPN11E76K突变也对驻留的HSCs产生不利影响 转基因小鼠(PTPN11E76K/+/WNT1-Cre+)发展为骨髓增生性肿瘤(MPN)，这种恶性肿瘤 来源于野生型造血干细胞(HSCs)。此外，一种供体细胞来源的MPN(D-MPN) 在PTPN11E76K/+/Wnt1-Cre+小鼠体内发育，移植健康的BM细胞。这样做的总体目标是 应用于破译神经中PTPN11突变的细胞和分子机制 骨髓间质中的CREST来源的细胞可诱导MPN。该提案的中心假设是PTPN11 这些微环境细胞中的突变直接和/或间接地推动了白血病的发展 高激活的常驻HSCs。我们计划检验这一假设，并实现这一应用程序的目标 通过追求以下三个目标。1)。以确定细胞类型、蛋白质因子和/或神经递质 PTPN11激活的三叉神经节和其他神经脊衍生物突变对白血病的影响 在BM基质中。2)。确定PTPN11功能增益激活的分子机制 突变会破坏三叉神经核和其他神经脊来源细胞的活动。3)。要验证 骨髓微环境PTPN11病突变对NS患者的致病作用 患者来源的细胞。这项申请中提出的研究不仅将极大地促进我们对 NS白血病发生的潜在机制，也为合理设计新的 预防NS患者白血病发展和促进干细胞移植的治疗干预 NS相关性血液系统恶性肿瘤的治疗。

Project Summary Noonan Syndrome (NS), a developmental disorder characterized by congenital heart disease, dysmorphic facial structures, short stature, and mental retardation, is caused by germline mutations in the genes involved in the Ras signaling pathway. Patients with NS are at an increased risk of developing leukemia. The mechanisms underlying the leukemogenesis are not completely understood. NS is mainly (>50%) associated with germline heterozygous activating mutations in the protein tyrosine phosphatase PTPN11 (SHP2), and NS patients with PTPN11 mutations have the worst prognosis. Studies from our laboratory and others have established the causal role of hematopoietic cell intrinsic PTPN11 mutations in the pathogenesis of NS- associated leukemia. Notably, in the last funding period we discovered that PTPN11 activating mutations (E76K or D61G) in the bone marrow (BM) stroma, specifically Nestin-expressing and Nestin-expressing cell- derived mesenchymal stem cells and osteoprogenitors, contributed significantly to the development/ progression of hematological malignancies in mouse models. However, our understanding of the effects of PTPN11 disease mutations in the BM microenvironment is still incomplete. Our recent pilot data indicate that PTPN11 activating mutations in the peripheral nervous system (PNS) and other neural crest-derived progeny in the BM stroma also exert detrimental effects on resident HSCs  neural crest-specific PTPN11E76K mutation knock-in mice (PTPN11E76K/+/Wnt1-Cre+) developed a myeloproliferative neoplasm (MPN), and this malignancy originated from wild-type hematopoietic stem cells (HSCs). Furthermore, a donor cell-derived MPN (D-MPN) developed in PTPN11E76K/+/Wnt1-Cre+ mice transplanted with healthy BM cells. The overall objective of this application is to decipher the cellular and molecular mechanisms by which the PTPN11 mutation in neural crest-derived cells in the BM stroma induce a MPN. The central hypothesis of the proposal is that the PTPN11 mutation in these microenvironmental cells drives leukemia development by directly and/or indirectly hyperactivating resident HSCs. We plan to test this hypothesis and accomplish the objective of this application by pursuing the following three aims. 1). To identify the cell type, protein factors, and/or neurotransmitters that mediate the leukemogenic effect of PTPN11 activating mutations in the PNS and other neural crest derivatives in the BM stroma. 2). To determine the molecular mechanisms by which PTPN11 gain-of-function activating mutations deregulate the activities of the PNS and other neural crest-derived cells. 3). To validate the pathogenic effects of BM microenvironmental PTPN11 disease mutations with NS patient specimens and patient-derived cells. The research proposed in this application will not only greatly advance our understanding of the mechanisms underlying the leukemogenesis in NS, but also inform the rational design of new therapeutic interventions for preventing leukemia development in NS and improving stem cell transplantation therapy for NS-associated hematological malignancies.