Neural control of pancreatic endocrine function in obesity and diabetes

我们的长期目标是通过精确控制胰腺神经活动来实现糖尿病治疗。我们将创建一个详细的和系统的视图定义胰腺神经，其基因表达谱，功能和高脂肪饮食（HFD）的影响，这是实现这一目标所必需的。我们的试验数据已经表明，HFD会导致胰腺神经结构的快速破坏，以及它们控制胰岛素释放的能力。我们的提案将通过结合3D成像，RNAseq和神经调节工具，带来前所未有的精确度和特异性，从而为胰腺神经控制血糖创造新的见解，我们拥有独特而深厚的经验。如果没有这些知识，成功靶向神经通路以控制糖尿病患者血糖的可能性仍然很小。该提案的总体目标是实现治疗糖尿病的新途径的下一步，是了解HFD对胰腺副交感神经和交感传出神经的结构，转录组和功能的影响。我们的中心假设是，HFD增加胰岛交感神经支配，减少胰岛副交感神经支配，导致胰岛素不足，以维持正常的葡萄糖。所提出的研究的基本原理是胰岛受交感神经和副交感神经的高度支配，HFD破坏胰腺神经结构、基因表达和功能。然而，我们不知道HFD的结构变化是否一致，哪些内分泌细胞受到影响或时间过程。我们还没有一个全面的基因表达谱神经支配胰腺或分子通路被HFD破坏。此外，我们不知道胰腺副交感神经和交感神经的确切功能，也不知道HFD如何影响这些作用。这些是我们理解上的重大差距。为了检验我们的中心假设并达到总体目标，我们将a）确定HFD对胰岛交感神经和副交感神经传出神经的3D结构的影响，B）确定HFD对胰腺交感神经和副交感神经传出神经中基因表达的影响，B）确定HFD对胰岛交感神经和副交感神经调节胰岛激素释放的功能的影响。为此，我们将使用清除胰腺的3D成像来确定低（10%）或HFD（45%）对胰腺副交感神经和交感神经结构的影响及其与进食和禁食小鼠中β，α和δ细胞的关系。我们将使用单细胞RNAseq来鉴定HFD对胰腺副交感神经和交感神经中HFD破坏的基因表达和分子途径的影响。我们将使用高度靶向神经调节来确定HFD对胰腺交感神经和副交感神经功能的影响。拟议的研究将全面了解胰腺交感神经和副交感神经支配的独特生物学，为未来确定预防和治疗2型糖尿病的关键时期，可逆性和治疗靶点的研究奠定重要基础。

Our long-term goal is to enable diabetes treatments through precise control of pancreatic nerve activity. We will create a detailed and systemic view of defined pancreatic nerves, their gene expression profiles, function and the effects of high fat diet (HFD) that are necessary to achieve this. Our pilot data already suggest HFD causes rapid disruption of pancreatic nerve structure and their ability to control insulin release in response to blood glucose. Our proposal will create new insights into pancreatic nerves' control of blood glucose by bringing an unprecedented level of precision and specificity by combining 3d imaging, RNAseq and neuromodulation tools in which we have unique and deep experience. Without this knowledge, the likelihood of successfully targeting neural pathways to control blood glucose in diabetes will remain remote. The overall objective of this proposal, which is the next step toward attaining new avenues to treat diabetes, is to understand the effects of HFD on the structure, transcriptome and function of pancreatic parasympathetic and sympathetic efferent nerves. Our central hypothesis is that HFD increases islet sympathetic innervation and reduces islet parasympathetic innervation leading to insufficient insulin to maintain normal glucose. The rationale that underlies the proposed research is that pancreatic islets are highly innervated by sympathetic and parasympathetic nerves and HFD disrupts pancreatic nerve structure, gene expression and function. However, we do not know if the structural changes from HFD are uniform, which endocrine cells are affected or the time course. We do not have a comprehensive gene expression profile of neurons innervating the pancreas or the molecular pathways disrupted by HFD. In addition, we do not know the precise functions of pancreatic parasympathetic and sympathetic nerves or how HFD affects these roles. These represent major gaps in our understanding. To test our central hypothesis and attain the overall objective, we will a) determine the effects of HFD on the 3D structure of islet sympathetic and parasympathetic efferent nerves, b) determine the effects of HFD on gene expression in pancreatic sympathetic and parasympathetic efferent nerves b) determine the effects of HFD on the function of islet sympathetic and parasympathetic nerves to regulate islet hormone release. To do so, we will use 3D imaging of cleared pancreata to determine the effects of low (10%) or HFD (45%) on pancreatic parasympathetic and sympathetic nerve structure and their relationship with beta, alpha and delta cells in fed and fasted mice. We will use single cell RNAseq to identify the effects of HFD on gene expression and the molecular pathways disrupted by HFD in pancreatic parasympathetic and sympathetic nerves. We will use highly target neuromodulation to determine the effects of HFD on pancreatic sympathetic and parasympathetic nerve function. The proposed studies will provide a comprehensive understanding of the unique biology of pancreatic sympathetic and parasympathetic innervation to form a crucial foundation for future studies identifying critical periods, reversibility and therapeutic targets to prevent and treat type 2 diabetes.