Regulating SNARE mechanisms to remediate glucose homeostasis

项目摘要-2型糖尿病(T2D)困扰着近10%的美国人口(约3000万人)；a 令人震惊的是，还有8400万人患有糖尿病前期，并显示出糖耐量受损的迹象。使这一点复杂化 问题是，某些胰岛素敏感型药物正在全球市场暂停销售，导致糖尿病前期和 T2D患者几乎没有治疗选择，迫切需要新的治疗方法。因为多个- 组织功能障碍有助于糖尿病前期和发展为T2D，预防或逆转这些疾病 需要多管齐下。具体地说，胰腺β细胞功能障碍和骨骼肌胰岛素 抵抗是人类糖尿病前期和T2D的主要特征。STX4，圈套的主要组成部分 胞吐机制，减少了β-细胞和来自人类的干细胞。此外，还需要使用STX4 小鼠模型和人胰岛的正常β细胞胰岛素分泌和SKM胰岛素敏感性。我们的长期合作 目标是了解β-细胞和SKM信号如何被操纵来预防或逆转糖尿病前期和 停止向T2D的进展。我们的中心假设是，STX4的浓缩支持β细胞和/或骨骼 预防和逆转糖尿病应激对肌肉的损害作用。建议的理由是 研究表明，一旦STX4的这些新机制被阐明，STX4信号就可以被操纵来 防止或反转T2D。在上一个资助周期中，我们揭示了stx4在促进β-cell方面的新角色。 生存与SKM功能。事实上，在这些组织中过度表达STX4的小鼠有显著的33% 延长寿命，防止衰老和饮食引起的代谢功能障碍。此外，我们还展示了 STX4可以逆转肥胖小鼠的胰岛素抵抗。然而，STX4的组织特异性作用尚不清楚。 因此，我们还产生了可诱导的β细胞和SKM特异性的stx4过表达和基因敲除小鼠 作为组织特异性STX4浓缩的基于RNA的候选疗法。我们挑衅性的新预赛 研究表明，stx4参与了β细胞的抗炎信号转导，并定位于细胞外 线粒体膜调节SKM的线粒体功能。因此，此应用程序的目标是 是为了测试这些候选机制，这些机制将stx4浓缩和保护β-细胞和SKM 糖尿病应激和评估STX4强化治疗的候选药物。我们将使用我们诱导的小鼠 用于这些研究的模型和人体组织/细胞。在目标1中，我们将评估 STX4在β细胞中的保护作用和测试新的β细胞STX4浓缩策略；在目标2中，我们将 描述STX4的增加如何保护SKM以及它如何逆转HFD诱导的功能障碍。我们将使用 创新的分子工具在以翻译为重点的背景下测试关于STX4作用的新假说 希望之城的制度环境。这项工作将对糖尿病研究产生积极影响 有望逆转糖尿病前期和阻止进展为T2D的候选策略以及通过发现新的 血糖调节机制。

Project Summary - Type 2 diabetes (T2D) plagues nearly 10% of the US population (~30 million people); a shocking 84 million more have prediabetes and show signs of impaired glucose tolerance. Compounding this problem, certain insulin-sensitizing drugs are undergoing global market suspensions, leaving prediabetic and T2D patients with few treatment options and creating an urgent need for new therapeutics. Because multi- tissue dysfunction contributes to prediabetes and progression to T2D, prevention or reversal of these diseases requires a multi-pronged approach. Specifically, pancreatic β-cell dysfunction and skeletal muscle (skm) insulin resistance are primary features of human prediabetes and T2D. STX4, a primary component of the SNARE exocytosis machinery, is reduced in β-cells and skm from humans with T2D. Furthermore, STX4 is required for normal β-cell insulin secretion and skm insulin sensitivity in mouse models and human islets. Our long-term goal is to understand how β-cell and skm signaling can be manipulated to prevent or reverse prediabetes and halt the progression to T2D. Our central hypothesis is that STX4 enrichment supports β-cells and/or skeletal muscle to prevent and reverse the damaging effects of diabetogenic stress. The rationale for the proposed research is that once these new mechanisms of STX4 are elucidated, STX4 signaling can be manipulated to prevent or reverse T2D. During the last funding cycle, we revealed new roles for STX4 in promoting β-cell survival and skm function. Indeed, mice overexpressing STX4 in these tissues have a remarkable 33% extended lifespan and are protected from aging- and diet-induced metabolic dysfunction. Also, we showed that STX4 can reverse insulin resistance in obese mice. However, the tissue-specific role of STX4 was unknown. Therefore, we generated inducible β-cell- and skm- specific STX4 overexpression and knockout mice, as well as RNA-based candidate therapeutics for tissue-specific STX4 enrichment. Our provocative new preliminary data indicate that STX4 participates in anti-inflammatory signaling in the β-cells, and localizes to the outer mitochondrial membrane to regulate mitochondrial function in skm. Therefore, the objective of this application is to test these candidate mechanisms linking STX4 enrichment and protection of β-cells and skm from diabetogenic stress and to evaluate candidate STX4 enrichment therapeutics. We will use our inducible mouse models and human tissues/cells for these studies. In Aim 1, we will evaluate the mechanisms underlying the protective actions of STX4 in β-cells and test novel β-cell STX4 enrichment strategies; in Aim 2, we will delineate how STX4 enrichment protects skm and how it reverses HFD-induced dysfunction. We will use innovative molecular tools to test novel hypotheses about STX4 action in the context of a translation-focused institutional environment at City of Hope. This work will positively impact diabetes research by evaluating a promising candidate strategy to reverse prediabetes and halt progression to T2D and by uncovering novel mechanisms of glycemic regulation.