Regional and lobular heterogeneity of human pancreas morphology and function in type 1 diabetes pathogenesis

通过糖尿病胰腺器官捐赠者网络(NPOD)等项目，非常有价值 来自不同阶段和病程的1型糖尿病(T1D)患者的组织现在可以买到。结果, 我们对T1D发生的致病事件的集体知识有了很大的提高。 然而，同时评估人类胰腺的功能和形态特征的研究还没有 限制了我们对控制健康中器官生理学的过程的理解 T1D的病理生理学。尽管有重要的研究资源，但对孤立岛屿的调查是 被分离程序搞混了，这会引起炎症反应，形态改变， 并改变了基因表达。此外，隔离程序依赖于胰岛的结构完整性 经得起酶和机械分选过程。最重要的是，将小岛与它们的 周围组织去除关于局部相邻元素的任何影响和信息，这可能 很重要，特别是在病态环境中。我们认为胰岛和外分泌的特征 组织(功能、调节和细胞相互作用)及其在T1D发病机制中的作用 通过对含有完整胰岛和腺泡的活的人胰腺组织的研究而得到改进。我们建议 利用极新的胰腺组织切片技术大幅扩展我们对内分泌的认识 和外分泌功能及其在正常(即对照)和T1D胰腺组织中的相互作用 NPOD程序。这项技术最初是由斯皮尔博士(MPD/PI，HMGU)创立的，可以生产出 新鲜的胰腺组织，机械损伤最小，无需酶消化；实现原位 在相对不受干扰的组织环境中进行胰岛细胞生物学的研究。跟随功能刺激 内分泌(胰岛素和高血糖素)和外分泌(淀粉酶、脂肪酶、胰蛋白酶原)以及 细胞信号(钙离子通量)的动态成像研究，切片将被固定并通过三维形态计量学进行分析。 在将要解决的许多问题中，我们试图提高我们对功能 小叶和区域性(即头部、体部或尾部)异质性胰腺形态的含义，包括 胰岛密度、大小和细胞组成、外分泌酶的表达和分布以及血管和 神经元密度。此外，我们的目标是探讨其在不同的小叶和区域病理中的作用。 T1D的进展(即，岛炎、β细胞功能障碍和破坏、腺泡细胞/器官质量丧失)。因此，我们 摆姿势测试不同器官重量减轻以及小叶异质性的胰岛素炎的假设 人T1D胰腺内β细胞的破坏是区域间和小叶内的结果 内分泌和外分泌胰腺形态和功能的差异。我们的目标是关联小岛 以及外分泌生理学和病理生理学对它们在胰腺内的位置和细胞特性的影响 对周围微环境的影响；应对T1D预防/逆转尝试产生影响的努力。

Through programs such as the Network for Pancreatic Organ donors with Diabetes (nPOD), highly valuable tissues from persons with various stages and durations of type 1 diabetes (T1D) are now available. As a result, our collective knowledge of the pathogenic events underlying T1D development has improved substantially. However, studies simultaneously assessing functional and morphological traits of the human pancreas have not been performed, limiting our understanding of the processes governing organ physiology in health versus pathophysiology in T1D. Despite being in important research resource, investigations of isolated islets are confounded by the isolation procedure, which induces an inflammatory response, morphological modifications, and altered gene expression. Furthermore, the isolation procedure relies on the structural integrity of the islets to withstand the enzymatic and mechanical sorting process. Most importantly, separation of islets from their surrounding tissue removes any influence and information regarding the local adjacent elements, which could be of importance, especially in pathological settings. We believe the characterization of islets as well as exocrine tissues (function, regulation, and cellular interactions) and their roles in the pathogenesis of T1D would be improved through studies of viable human pancreatic tissue containing intact islets and acini. We propose to utilize the extremely novel pancreas tissue slice technology to substantially expand our knowledge of endocrine and exocrine function and their interaction in normal (i.e., control) and T1D pancreas tissues obtained through the nPOD program. This technology, originally established by Dr. Speier (mPD/PI, HMGU), produces “slices” of fresh pancreatic tissue with minimal mechanical damage and without enzymatic digestion; enabling in situ investigations of islet cell biology in a relatively unperturbed tissue setting. Following functional stimulation assays for endocrine (insulin and glucagon) and exocrine secretion (amylase, lipase, trypsinogen) as well as dynamic imaging studies of cellular signaling (Ca2+ flux), slices will be fixed and analyzed by 3D morphometry. Amongst the many questions that will be addressed, we seek to improve our understanding on the functional implications of the lobular and regional (i.e., head, body or tail) heterogeneous pancreatic morphology, including islet density, size and cellular composition, exocrine enzyme expression and distribution, as well as vascular and neuronal density. Furthermore, we aim to address its role in the distinct lobular and regional pathological progression of T1D (i.e., insulitis, β-cell dysfunction and destruction, loss of acinar cell/organ mass). Thus, we pose to test the hypothesis that the disparate organ weight loss as well as the lobular heterogeneity of insulitis and β-cell destruction within the human T1D pancreas is the result of inter-regional and intra-lobular differences in endocrine and exocrine pancreas morphology and function. Our objective is to correlate islet and exocrine physiology and pathophysiology to their location within the pancreas and to cellular characteristics of the surrounding microenvironment; efforts that should impact attempts at T1D prevention/reversal.