Beta cell endoplasmic reticulum stress and its crosstalk with immune system in ty

描述（由申请人提供）：1型糖尿病是由免疫介导的过程破坏胰岛素分泌细胞引起的。1型糖尿病在世界范围内的发病率不断上升，尤其是在儿童中，已经引起了极大的关注。尽管为确定这种疾病的根本原因作出了大量努力，但仍不清楚细胞被破坏的原因，是什么触发了最初的免疫破坏，以及如何预防或逆转这种破坏。由蛋白质错误折叠、慢性炎症和环境因素引起的内质网应激正在成为糖尿病发病的新范式。为了应对内质网应激，内质网膜定位传感器ATF6、IRE1和PERK介导的未折叠蛋白反应（UPR）信号级联被触发以重建细胞稳态。内质网应激和异常UPR已被证明在炎症和自身免疫性疾病（包括2型糖尿病和动脉粥样硬化）的发病机制中发挥作用。然而，内质网应激和UPR在T1DM的病理生理和自身免疫反应的开始和传播中的作用仍然不完全明确。我们声称，在疾病进展的早期，内质网细胞适应能力的丧失不仅会导致b细胞功能障碍，还会导致自身免疫反应的加剧。在为期三年的mentor Research Scientist Development K-Award培训期间，在我的K01导师团队的指导下，我提出了以下培训和研究计划：1)战略性的四管齐下的培训方法，学习如何设计、领导和执行一个多学科的研究项目；2)作为本次申请的研究目标，为未来的RO1拨款收集初步数据。该研究申请有两个具体目的：目的1：确定在疾病进展的不同阶段ATF6在细胞中的作用。我们假设在糖尿病进展过程中失去UPR的ATF6分支会破坏b细胞功能，并且根据缺失的阶段，它也会影响胰岛素的发展。为了验证这一假设，我们将使用最近生成的小鼠模型，该模型允许我们在非肥胖糖尿病（NOD）小鼠疾病进展期间的特定时间诱导删除细胞中的ATF6。目的2：探讨细胞内质网应激对淋巴细胞增殖、活化、迁移和极化的非自主性影响。我们假设细胞应激可以被淋巴细胞感知，并且这种外部应激可以导致免疫细胞的表型和/或分子变化。我们将通过体外共培养系统和体内过继转移实验来验证这一假设。这项工作的预期结果是详细描述普遍定期审议的ATF6分支，并对以前未研究的内质网应激驱动的细胞与免疫细胞之间的串扰有新的认识。这项工作有可能对了解内质网应激在T1DM中的作用产生重要影响，并促进更好的治疗和预防策略的发展。

DESCRIPTION (provided by applicant): Type 1 diabetes results from the destruction of the insulin-secreting ¿-cells by an immune mediated process. The increasing incidence of type 1 diabetes around the world, especially among children, has been of great concern. Despite intensive efforts to identify the underlying causes of this disease, it is still not clear why ¿-cels are destroyed, what triggers the initial immune destruction and how it could be prevented or reversed. Endoplasmic reticulum (ER) stress, caused by protein misfolding, chronic inflammation and environmental factors, is emerging as a novel paradigm for diabetes pathogenesis. To cope with ER stress, the Unfolded Protein Response (UPR), a signaling cascade mediated by ER membrane-localized sensors ATF6, IRE1 and PERK, is triggered to re-establish cellular homeostasis. ER stress and aberrant UPR have been shown to play a role in the pathogenesis of inflammatory and autoimmune diseases including type 2 diabetes and atherosclerosis. However, the role of ER stress and the UPR in pathophysiology and in the initiation and propagation of the autoimmune responses in T1DM remains incompletely defined. We claim that the loss of ER adaptive capacity in ¿-cells early in disease progression can lead not only to b-cell dysfunction, but also contribute to an aggravated autoimmune response. For this three- year Mentored Research Scientist Development K-Award training period, and with the guidance of my K01 mentorship team, I propose the following training and research plan: 1) a strategic four-pronged training approach to learn how to design, lead and execute a multidisciplinary research project, and 2) as the research objective of this application, collect preliminary data for a future RO1 grant. The research application has two specific aims: Aim 1: To determine the role of ATF6 in ¿-cells during different stages of disease progression. We hypothesize that losing the ATF6 branch of the UPR during diabetes progression will disrupt b-cell function, and depending on the stage of the deletion, it will also affect insulitis developmen. To test this hypothesis, we will use a recently generated mouse model that allows us to inducibly delete ATF6¿ specifically in ¿-cells at defined times during disease progression in non-obese diabetic (NOD) mice. Aim 2: To examine cell non-autonomous effects of ¿-cell ER stress on lymphocyte proliferation, activation, migration and polarization. We hypothesize that ¿-cell stress can be sensed by lymphocytes and that this extrinsic stress can lead to phenotypic and/or molecular changes in immune cells. We will test this hypothesis by using ex vivo co-culture systems and in vivo adoptive transfer experiments. The expected outcome of the proposed work is a detailed characterization of the ATF6 branch of the UPR and new understanding of a previously unstudied area of ER stress-driven cross talk between ¿-cells and immune cells. This work has the potential to make an important impact on understanding the role of ER stress in T1DM and promote development of better therapeutic and preventive strategies.