Model for SorCS1-mediated Diabetes with Dementia

SorCS1 介导的糖尿病伴痴呆模型

• 批准号: 8788636
• 负责人: SAMUEL E. GANDY
• 金额: $ 37.08万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8788636
• 关键词: Aging; Alzheimer' s Disease; Alzheimer' s disease risk; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Brain; Characteristics; Complex; Cultured Cells; Data; Dementia; Diabetes Mellitus; Disease; Family; Female; Functional disorder; Gender; Gene Transfer; Generations; Genetic; Genetic Polymorphism; Human; Insulin; Insulin Resistance; Link; Mediating; Metabolic; Metabolism; Modeling; Molecular; Mus; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Patients; Phenotype; Phosphorylation; Protein Precursors; Proteins; Risk; Role; Serine; Structure; Tertiary Protein Structure; Testing; Transgenic Mice; Vacuolar Protein Sorting; Vertebral column; Viral Genes; Work; amyloid peptide; genetic association; genetic linkage; glucose metabolism; glucose tolerance; hippocampal morphometry; hypercholesterolemia; insulin tolerance; learned behavior; overexpression; protein complex; protein metabolism; protein transport; sexual dimorphism; sortilin; trafficking

SUMMARY Type 2 diabetes mellitus (T2D or T2DM) increases the risk for Alzheimer's disease (AD), and SORCS1 is genetically linked to both T2D and AD. We have undertaken a study of the possible role(s) for SorCS1 in metabolism of the Alzheimer's amyloid-¿ (¿¿) precursor protein (APP), in order to define the molecular mechanisms underlying this coordinate genetic linkage to both diseases. Overexpression of SorCS1c¿-myc in cultured cells caused a reduction (p=0.002) in ¿¿ generation (Lane et al., 2010). Endogenous murine A¿40 and ¿¿42 levels were increased (A¿40, p=0.044; A¿42, p=0.007) in the brains of female Sorcs1 hypomorphic mice, possibly paralleling the sexual dimorphism that is characteristic of the genetic associations of SORCS1 with AD and DM. Since SorL1, another AD-linked Vps10-domain protein, directly interacts with Vps35 to modulate APP metabolism, we investigated the possibility that SorCS1c¿-myc might interact with APP, SorL1, and/or Vps35. We readily recovered SorCS1:APP, SorCS1:SorL1, and SorCS1:Vps35 complexes from nontransgenic mouse brain. Notably, total Vps35 protein levels were decreased by 49% (p=0.009) and total SorL1 protein levels were decreased by 29% (p=0.003) in the brains of female Sorcs1-/- mice. We hypothesize that dysfunction of SorCS1 may contribute to both the APP/¿¿ disturbance underlying AD and the insulin/glucose metabolism disturbance underlying DM. In order to test this hypothesis further, we propose the following specific aims: Specific Aim 1. To evaluate the importance of SorCS1 protein interaction motifs and SorCS1/SorL1/APP complex formation on APP metabolism by: (a) Characterizing APP metabolism in cultured cells overexpressing SorCS1; (b) Testing the effects of mutations of protein-protein interacting motifs in the cytoplasmic and ectodomains of SorCS1 on both the formation of tripartite SorCS1/SorL1/APP complexes and APP metabolism; (c) Testing the effect of a putative pathogenic SorCS1 polymorphism on both the formation of tripartite SorCS1/SorL1/APP complexes and APP metabolism; (d) Confirming the importance of functional domains identified in Aim 1aii and 1aiii by viral gene transfer into primary cultures. Specific Aim 2. To employ Sorcs1 hypomorphic and plaque- forming human Swedish APP/PS bigenic mice crossed with Sorcs1 hypomorphic mice for characterization of: (i) endogenous APP metabolism; (ii) hippocampal morphometry, dendritic arborization, and spine structure; (c) learning behavior. Aging (3 mo, 6 mo, 12 mo) effects will also be studied. Specific Aim 3. To perform standard glucose and insulin tolerance tests and metabolic profile phenotyping of Sorcs1-/- mice and plaque-forming" human Swedish APP/PS co-transgenic mice crossed with Sorcs1 -/- mice.

概括 2 型糖尿病（T2D 或 T2DM）会增加患阿尔茨海默病 (AD) 的风险，而 SORCS1 是 与 T2D 和 AD 均存在遗传相关。我们对 SorCS1 的可能作用进行了研究 阿尔茨海默病淀粉样蛋白-¿ (¿¿) 前体蛋白 (APP) 的代谢，以确定分子 这种协调与两种疾病的遗传联系的机制。 SorCS1c¿-myc 的过度表达 培养细胞中的 β-内酰胺酶导致细胞世代减少 (p=0.002) (Lane et al., 2010)。内源性小鼠 女性 Sorcs1 大脑中的 A¿40 和 ¿42 水平升高（A¿40，p=0.044；A¿42，p=0.007） 亚型小鼠，可能与遗传特征的性别二态性平行 SORCS1 与 AD 和 DM 的关联。由于SorL1（另一种AD连接的Vps10结构域蛋白）直接 与 Vps35 相互作用来调节 APP 代谢，我们研究了 SorCS1c¿-myc 可能的可能性 与 APP、SorL1 和/或 Vps35 交互。我们很容易恢复了 SorCS1:APP、SorCS1:SorL1 和 来自非转基因小鼠大脑的 SorCS1:Vps35 复合物。值得注意的是，总 Vps35 蛋白水平 大脑中的 SorL1 总蛋白水平降低了 49% (p=0.009)，总 SorL1 蛋白水平降低了 29% (p=0.003) 雌性 Sorcs1-/- 小鼠。我们假设 SorCS1 的功能障碍可能会导致 APP/¿ AD 潜在的紊乱和 DM 潜在的胰岛素/葡萄糖代谢紊乱。为了测试 进一步这个假设，我们提出以下具体目标： 具体目标 1. 评估重要性 SorCS1 蛋白相互作用基序和 SorCS1/SorL1/APP 复合物形成对 APP 代谢的影响：(a) 表征过度表达 SorCS1 的培养细胞中的 APP 代谢； (b) 测试效果 SorCS1 的胞质和胞外域中蛋白质-蛋白质相互作用基序的突变 SorCS1/SorL1/APP 三联复合物的形成和 APP 代谢； (c) 测试效果 推定致病性 SorCS1 多态性对三联 SorCS1/SorL1/APP 复合物形成的影响 和APP代谢； (d) 通过以下方式确认目标 1aii 和 1aiii 中确定的功能域的重要性： 病毒基因转移到原代培养物中。具体目标 2. 使用 Sorcs1 亚效型和斑块- 形成人类瑞典 APP/PS 双基因小鼠与 Sorcs1 低等态小鼠杂交以进行表征 (i) 内源性 APP 代谢； (ii) 海马形态测量、树突分枝和脊柱 结构; (c) 学习行为。还将研究老化（3 个月、6 个月、12 个月）的影响。具体目标 3. 至 对 Sorcs1-/- 小鼠进行标准葡萄糖和胰岛素耐量测试以及代谢谱表型分析 和斑块形成的”人类瑞典 APP/PS 共转基因小鼠与 Sorcs1 -/- 小鼠杂交。