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， 现在可获得来自患有不同阶段和持续时间的1型糖尿病（T1 D）的人的组织。因此，在本发明中， 我们对T1 D发展背后的致病事件的集体知识已经有了实质性的提高。 然而，同时评估人类胰腺功能和形态特征的研究还没有 进行，限制了我们对健康与 T1 D的病理生理学尽管是重要的研究资源，但对孤立胰岛的研究仍是 由于分离过程而混淆，分离过程诱导炎症反应，形态学改变， 改变基因表达。此外，隔离程序依赖于胰岛的结构完整性 以承受酶和机械分选过程。最重要的是，将胰岛与它们的 周围组织去除了关于局部相邻元件的任何影响和信息， 重要性，尤其是在病理环境中。我们相信小岛和外分泌的特征 组织（功能，调节和细胞相互作用）及其在T1 D发病机制中的作用将是 通过对含有完整胰岛和腺泡的活的人类胰腺组织的研究得到了改善。我们建议 利用极其新颖的胰腺组织切片技术， 和外分泌功能以及它们在正常情况下的相互作用（即，对照）和T1 D胰腺组织， NPOD计划这项技术最初由Speier博士（mPD/PI，HMGU）建立， 新鲜胰腺组织，机械损伤最小，无酶消化;能够原位 在相对不受干扰的组织环境中进行胰岛细胞生物学研究。功能性刺激后 内分泌（胰岛素和胰高血糖素）和外分泌（淀粉酶、脂肪酶、胰蛋白酶原）测定以及 在细胞信号传导（Ca 2+通量）的动态成像研究中，将切片固定并通过3D形态测定法分析。 在众多的问题中，我们试图提高我们对功能的理解， 小叶和区域的含义（即，头、体或尾）异质胰腺形态，包括 胰岛密度、大小和细胞组成、外分泌酶表达和分布以及血管和 神经元密度此外，我们的目标是解决其在不同的小叶和区域病理学的作用， T1 D的进展（即，胰岛炎、β细胞功能障碍和破坏、腺泡细胞/器官质量损失）。因此我们 姿势来检验这一假设，即不同器官的重量损失以及胰岛炎的小叶异质性 人T1 D胰腺内的β细胞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。我们的目标是将胰岛 以及外分泌生理学和病理生理学与它们在胰腺内的位置和细胞特性的关系 周围微环境的影响;应影响T1 D预防/逆转尝试的努力。

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.