Physiology/Pathophysiology of Vitamin B1 Transport in Pancreatic Acinar Cells

胰腺腺泡细胞中维生素 B1 运输的生理学/病理生理学

基本信息

批准号：
10799411
负责人：
HAMID M SAID
金额：
$ 57.99万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-03-02 至 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10799411
关键词：
Acinar Cell Acute Address Affect Cell membrane Cells Cellular biology Chronic Circulation Complex Cytoplasm Diphosphates Disease Endocrine Endotoxins Energy Metabolism Environmental Risk Factor Event Exposure to Failure Flagellin Functional disorder Funding Genes Goals Health Homeostasis Human Impairment Inflammatory Interleukin-1 beta Interleukin-6 Investigation Knockout Mice Knowledge Lead Lipopolysaccharides Luciferases Maintenance Mediating Metabolic MicroRNAs Micronutrients Mitochondria Molecular Molecular Biology Morbidity - disease rate Mus Organ Organelles Oxidation-Reduction Oxidative Stress Pancreas Pancreatic Diseases Physiological Physiology Play Post-Transcriptional Regulation Process Production Proteins Regulation Reporter Genes Research Role Structure System TNF gene Testing Thiamine Transcriptional Regulation Transgenic Mice Transport Process Vitamin Deficiency Vitamins Water-Soluble Vitamin alcohol exposure cigarette smoke cytokine design improved micronutrient deficiency mortality mouse model novel nutrition programs promoter uptake

项目摘要

Vitamin B1 (thiamin) is indispensable for normal function/health of pancreatic cells due its critical roles in oxidative energy metabolism, ATP production, and in maintaining normal cellular redox state. Low intracellular level of thiamin leads to acute energy failure, oxidative stress, and impairment in mitochondrial function. At the organ level, the metabolically active pancreas maintains high levels of thiamin, and deficiency of the vitamin impairs its functions. The pancreas cannot synthesis thiamin endogenously; rather it obtains it from circulation. The overall goal of this research program since its inception has been focused on developing a comprehensive understanding of the molecular mechanisms involved in thiamin uptake by pancreatic acinar cells (PACs) and the subsequent transport (compartmentalization) of its major intracellular form, i. e., thiamin pyrophosphate (TPP), into mitochondria, how these processes are regulated, and how they are affected by exposure to external/internal factors that are known to adversely affect the normal physiology/health of the pancreas. We have addressed many of these issues, and in the current proposal aim at determining: i) the role of microRNAs in post-transcriptional regulation of THTR-1, THTR-2, and the mitochondrial TPP transporter (MTPPT) expression in PACS, and the uptake processes that they mediate; ii) whether THTR- 1 and THTR-2 of PACs have interacting partners that affect/regulate their physiology/cell biology; and iii) the effect of specific factors that PACs are exposed to under certain pathophysiological conditions [pro-inflammatory cytokines, and the bacterial lipopolysaccharide (LPS) and flagellin] on thiamin uptake and on transport of TPP into their mitochondria. Thus, in new preliminary studies evidence were obtained to suggest that microRNAs regulate THTR-1 expression and thiamin uptake by PACs, that THTR-1 has interacting partner(s), and that exposure of PACs to pro-inflammatory cytokines (especially those implicated in pancreatic disorders like IL- 6, TNF-α and IL-1β), as well as to LPS and flagellin, inhibit cellular thiamin uptake and transport of TPP into mitochondria. Based on these new findings, our working hypotheses are: i) microRNAs play an important role in post-transcriptional regulation of THTR-1, THTR-2, and MTPPT expression in PACs and the uptake events they mediate; ii) PACs THTR-1 and THTR-2 have interacting partners that affect/regulate their physiology/cell biology; and iii) pro- inflammatory cytokines, LPS and flagellin negatively impact PACs thiamin transport physiology. We plan to test these hypotheses by accomplishing two specific aims and will utilize state-of the art cellular/molecular approaches, human and mouse PACs, and appropriate transgenic mouse models. Results of these investigations should provide novel information regarding vitamin B1 cellular/molecular transport physiology in PACs and how internal/external factors affect the involved transport events. Such knowledge may ultimately assist in the designing of effective strategies to optimize pancreatic thiamin homeostasis, and thus, improve the health of the pancreas.

维生素 B1（硫胺素）对于胰腺细胞的正常功能/健康至关重要，因为它在氧化能量代谢、ATP 产生以及维持正常的细胞氧化还原状态。细胞内硫胺素水平会导致急性能量衰竭、氧化应激和线粒体损伤在器官水平上，代谢活跃的胰腺维持高水平的硫胺素和缺乏。维生素的减少会损害其功能，但胰腺不能内源合成硫胺素；该研究计划自启动以来的总体目标一直集中在发展。全面了解胰腺腺泡摄取硫胺素的分子机制细胞（PAC）及其主要细胞内形式（即硫胺素）的后续运输（区室化）。焦磷酸盐（TPP）进入线粒体，这些过程是如何调节的，以及它们如何受到影响暴露于已知会对正常生理/健康产生不利影响的外部/内部因素我们已经解决了其中许多问题，并且在当前的提案中旨在确定：i) 的作用。 microRNA 在 THTR-1、THTR-2 和线粒体 TPP 转运蛋白转录后调节中的作用 (MTPPT) 在 PACS 中的表达，以及它们介导的摄取过程；ii) THTR-1 和 THTR-2 是否存在；的 PAC 具有影响/调节其生理学/细胞生物学的相互作用伙伴；以及 iii) 的影响； PAC 在某些病理生理条件下暴露于的特定因素 [促炎症细胞因子、细菌脂多糖 (LPS) 和鞭毛蛋白]对硫胺素摄取和 TPP 转运的影响因此，在新的初步研究中获得的证据表明 microRNA 存在。调节 THTR-1 表达和 PAC 摄取硫胺素，THTR-1 具有相互作用的伴侣，并且 PAC 暴露于促炎细胞因子（尤其是与 IL-1 等胰腺疾病相关的细胞因子） 6、TNF-α 和 IL-1β）以及 LPS 和鞭毛蛋白，抑制细胞硫胺素摄取和 TPP 转运基于这些新发现，我们的工作假设是：i) microRNA 发挥着重要作用。 PAC 中 THTR-1、THTR-2 和 MTPPT 表达的转录后调控以及摄取事件它们介导；ii) PAC THTR-1 和 THTR-2 具有影响/调节其生理/细胞的相互作用的伙伴生物学；以及 iii) 促炎细胞因子、LPS 和鞭毛蛋白对 PAC 硫胺素转运产生负面影响我们计划通过实现两个具体目标来测试这些假设，并将利用现状。细胞/分子方法、人类和小鼠 PAC 以及适当的转基因小鼠模型。这些研究应提供有关维生素 B1 细胞/分子运输的新信息 PAC 的生理学以及内部/外部因素如何影响所涉及的运输事件。最终可能有助于设计有效的策略来优化胰腺硫胺素稳态，并且因此，改善胰腺的健康。