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

描述(申请人提供)：1型糖尿病是由免疫调节过程中胰岛素分泌细胞的破坏引起的。世界各地1型糖尿病发病率的上升，特别是在儿童中的发病率，已经引起了极大的关注。尽管为查明这种疾病的根本原因进行了密集的努力，但仍不清楚为什么细胞被破坏，是什么触发了最初的免疫破坏，以及如何预防或扭转这种破坏。内质网应激是由蛋白质错误折叠、慢性炎症和环境因素引起的，正在成为研究糖尿病发病机制的新范式。为了应对内质网应激，触发了未折叠蛋白反应(UPR)，这是一个由ER膜定位的传感器ATF6、IRE1和PERK介导的信号级联反应，以重建细胞内稳态。内质网应激和异常的UPR已被证明在炎症和自身免疫性疾病的发病机制中发挥作用，包括2型糖尿病和动脉粥样硬化。然而，内质网应激和UPR在T1 DM的病理生理和自身免疫反应的启动和传播中的作用仍不完全清楚。我们声称，在疾病进展的早期，内质网适应能力的丧失不仅会导致b细胞功能障碍，还会导致加重的自身免疫反应。在这个为期三年的导师研究科学家发展K奖培训期间，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)战略四管齐下的培训方法，学习如何设计、领导和执行多学科研究项目；2)作为本申请的研究目标，为未来的RO1拨款收集初步数据。研究应用有两个特定的目的：目标1：确定ATF6在细胞中在疾病进展的不同阶段中的作用。我们推测，在糖尿病进展过程中失去UPR的ATF6分支将扰乱b细胞的功能，并且根据缺失的阶段，它也将影响胰岛素炎的发生。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型糖尿病(NOD)小鼠的疾病进展过程中，在指定的时间诱导特定的ATF6-细胞中的ATF6基因缺失。目的：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。我们假设淋巴细胞可以感受到细胞应激，这种外在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领养移植实验来检验这一假设。这项拟议工作的预期结果是，对UPR的ATF6分支进行了详细的表征，并对以前未研究过的内质网应激驱动的细胞与免疫细胞之间的串扰有了新的理解。这项工作有可能对理解内质网应激在T1 DM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.