Regulation of Neural Stem Cells and Neurogenesis by Autophagy Genes

在成人大脑中，神经前体/干细胞(NSCs)负责新神经元的生成 用于现有电路的维护和受伤后。NSC维护和/或缺陷 神经发生与发育缺陷和神经退行性疾病有关 其中，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在幼年和老年动物中的调节机制，可导致 治疗神经退行性疾病的有效方法。自噬是一种高度保守的细胞过程 大量细胞质物质的降解以维持细胞内稳态和功能障碍 自噬与多种疾病有关，包括神经变性和其他与年龄有关的疾病。 精神错乱。FIP200(FAK家族相互作用蛋白，200 kDa)是本实验室首次发现的一种蛋白。 随后显示为ULK1/Atg13/FIP200复合体的一个组分，对诱导 自噬。在之前的资助期间，我们发现，FIP200基因缺失，但没有其他自噬基因 ATG5、ATG7和ATg16L1导致神经干细胞维持和神经发生缺陷，提示ATG5、ATG7和ATG16L1可能在 FIP200通过控制p62聚集体的形成在NSC调控中的非典型作用。在……里面 进一步的初步研究，我们获得了严格的遗传学证据，表明FIP200的非正则功能是 通过生成和分析另一种独特的小鼠模型来维持和神经发生所需的神经干细胞 在神经干细胞中存在FIP200-4A突变，特异性地阻断FIP200的自噬功能。另外，我们发现 FIP200 C-末端区域(FIP200-CT)可以与p62相互作用，这与最近的研究表明 它在降解p62聚合体中的重要性。此外，我们还发现FIP200可以调节TBK1的激活， 它可以磷酸化P62以调节其降解，并且FIP200也与TBK1适配器相互作用， AZI2.在第二组初步研究中，我们分析了另一个自噬基因Beclin1在神经干细胞中的作用 使用新的Becn1Ki小鼠，发现增加的自噬保护了NSC池和它们的神经发生 对老龄的Becn1Ki小鼠，对幼年小鼠的NSC无影响。最后，我们获得了额外的初步数据。 提示氧化应激可能与自噬缺陷协同促进p62聚集体的形成。 在这些初步和先前研究的基础上，我们建议1)。研究FIP200的非典型功能及其与其自噬功能在调节神经干细胞中的潜在协同作用的机制。 分析增强自噬在防止NSC池下降和促进NSC死亡中的作用和机制 Becn1Ki小鼠的神经发生；3)。探索NSC维护和维护的作用和机制 氧化损伤后和衰老过程中自噬缺陷小鼠的神经发生。总而言之，这些研究将 通过自噬基因显著提高了我们对神经干细胞和神经发生的调控的理解 可能有助于未来设计有效的神经退行性疾病和其他相关疾病的治疗方法。

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.