Regulation of Neural Stem Cells and Neurogenesis by Autophagy Genes

在成人大脑中，神经祖细胞/干细胞（NSCs）负责产生新的神经元 用于现有电路的维护和受伤后。国家安全委员会的维护和/或 神经发生导致发育缺陷和神经退行性疾病 老龄化是一个主要的风险因素。 拟议研究的长期目标是确定分子和细胞 NSC在年轻和老年动物中的调节机制，这可能导致 神经退行性疾病的有效疗法。自噬是一种高度保守的细胞过程， 维持细胞内稳态的大量细胞质物质的降解， 自噬与各种疾病有关，包括神经变性和其他与年龄有关的疾病。 紊乱FIP 200（FAK-family Interacting Protein of 200 kDa）最初是在我们的实验室中鉴定的， 随后显示为ULK 1/Atg 13/FIP 200复合物的一种组分，对于诱导 自噬在之前的资助期间，我们发现，Fip 200的缺失，而不是其他自噬基因 Atg 5，Atg 7和Atg 16 L1，导致缺陷的NSC维持和神经发生，表明了潜在的作用， FIP 200通过控制p62聚集体的形成在NSC调节中的非经典功能。在 通过额外的初步研究，我们获得了严格的遗传学证据，证明FIP 200的非典型功能是 通过生成和分析另一种独特的小鼠模型， FIP 200 -4A突变特异性阻断FIP 200的自噬功能。另外，我们发现 FIP 200 C-末端区域（FIP 200-CT）可以与p62相互作用，这与最近的研究结果一致， 其在降解p62聚集体中的重要性。此外，我们发现FIP 200可以调节TBK 1的活化， 其可以磷酸化p62以调节其降解，并且FIP 200还与TBK 1衔接子相互作用， AZI 2.在第二组初步研究中，我们分析了另一个自噬基因Beclin 1在神经干细胞中的作用， 使用新的Becn 1 KI小鼠，发现增加的自噬保护了NSC库及其神经发生 而不影响年轻小鼠的NSC。最后，我们获得了额外的初步数据， 这表明氧化应激可能与自噬缺陷协同促进p62聚集体形成。 在这些初步和先前研究的基础上，我们建议1）。研究FIP 200的非经典功能的机制以及与其自噬功能在神经干细胞调控中的潜在协同作用，2）. 分析增强自噬防止NSC池下降和促进NSC池增殖的作用和机制。 Becn 1 KI小鼠的神经发生; 3）。探讨NSC维护的作用和机制， 氧化损伤后和衰老过程中自噬缺陷小鼠的神经发生。这些研究将 显著推进了我们对自噬基因调节NSC和神经发生的理解， 可能有助于未来设计有效的治疗神经退行性疾病和其他相关疾病的方法。

In adult brains, neural progenitor/stem cells (NSCs) are responsible for the generation of new neurons for the maintenance of the existing circuitry and after injuries. Deficiency in NSC maintenance and/or neurogenesis contributes to both developmental defects and neurodegenerative diseases for which aging is a major risk factor. The long-term goal of the proposed studies is to determine the molecular and cellular mechanisms of NSC regulation in both young and aged animals, which can lead to the development of effective therapies for neurodegenerative diseases. Autophagy is a highly conserved cellular process for degradation of bulk cytoplasmic materials for maintenance of cellular homeostasis, and dysfunctions in autophagy have been implicated in various diseases, including neurodegeneration and other age-related disorders. FIP200 (FAK-family Interacting Protein of 200 kDa) was initially identified in our laboratory and subsequently shown as one component of the ULK1/Atg13/FIP200 complex essential for the induction of autophagy. In the previous funding period, we found that, deletion of Fip200, but not other autophagy genes Atg5, Atg7 and Atg16L1, led to defective NSC maintenance and neurogenesis, suggesting a potential role for the non-canonical function of FIP200 in NSC regulation through controlling p62 aggregate formation. In additional prelim studies, we obtained rigorous genetic evidence that non-canonical function of FIP200 is required for NSC maintenance and neurogenesis by generation and analyses of another unique mouse model with FIP200-4A mutation in NSCs that blocks autophagy function of FIP200 specifically. Additionally, we found that the FIP200 C-terminal region (FIP200-CT) could interact with p62, consistent with recent studies showing its importance in degrading p62 aggregates. Moreover, we found that FIP200 can regulate TBK1 activation, which can phosphorylate p62 to regulate its degradation, and that FIP200 also interacts with the TBK1 adaptor, AZI2. In a second set of prelim studies, we analyzed the role of another autophagy gene Beclin1 in NSCs employing new Becn1 KI mice and found that increased autophagy protected NSC pool and their neurogenesis in aged Becn1 KI mice without affecting NSC in young mice. Lastly, we obtained additional prelim data suggesting that oxidative stress may synergize with autophagy-deficiency to promote p62 aggregate formation. Building upon these preliminary and prior studies, we propose to 1). investigate the mechanisms of non-canonical functions of FIP200 and potential synergy with its autophagy function in the regulation of NSCs, 2). analyze the role and mechanisms of enhanced autophagy to prevent NSC pool decline and promote neurogenesis in Becn1 KI mice, and 3). explore the role and mechanisms of NSC maintenance and neurogenesis in autophagy-deficiency mice after oxidative insult and during aging. Together, these studies will significantly advance our understanding of the regulation of NSC and neurogenesis by autophagy genes that may contribute to future design of effective therapies for neurodegenerative and other related diseases.