Hepatic GPR125: ligands and liver repair

肝脏 GPR125：配体和肝脏修复

• 批准号: 10452011
• 负责人: Blythe D Shepard
• 金额: $ 15.6万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10452011
• 关键词: ARNT gene; Adhesions; Adult; Agonist; Bile Acids; Bile fluid; Biological Assay; Cell Line; Cell Maintenance; Clustered Regularly Interspaced Short Palindromic Repeats; Coupled; Cues; Development; Diet; Disease; Drug Targeting; Energy-Generating Resources; Environment; Epithelial Cells; Extracellular Matrix; FDA approved; Family; Female; Functional Magnetic Resonance Imaging; Future; G-Protein-Coupled Receptors; Gene Family; Genome; Glucose; Guide RNA; Health; Hepatic; Homeostasis; Hormone Receptor; Human; Human body; Image; Immunofluorescence Immunologic; Injury; Intercellular Junctions; Investigation; Knock-out; Knockout Mice; Lead; Ligands; Link; Liver; Liver Regeneration; Maintenance; Mediating; Metabolic; Modeling; Mus; Mutate; N-terminal; NPBWR1 gene; Natural regeneration; Nature; Organ; Orphan; Pathway interactions; Pharmacology; Physiological; Physiology; Play; Process; Reporting; Sensory; Sensory Receptors; Site; Stress; Taste Buds; Testing; Tissues; Transmembrane Domain; Xenobiotics; Zebrafish; activation-induced cytidine deaminase; adenoviral-mediated; adhesion receptor; basolateral membrane; bile duct; cholangiocyte; injury and repair; interest; knock-down; liver function; liver injury; liver repair; male; man; member; olfactory receptor; planar cell polarity; preclinical development; prevent; receptor; regeneration following injury; tissue repair

Project Summary G protein-coupled receptors (GPCRs) are 7 transmembrane domain proteins that aid in the maintenance of homeostasis by responding to cues produced by the internal and external environment. In humans, there are more than 800 known GPCRs, and while more than 20% of all FDA-approved drugs target GPCRs, the vast majority of these receptors are understudied. In fact, many of these uncharacterized ‘orphan’ receptors, termed GPRs, are expressed at extremely high levels in different tissues suggesting that they likely have important, yet unknown, physiological functions. The liver is the largest metabolic tissue in the human body and is responsible for a number of important functions including sensing and detoxifying xenobiotics, metabolizing glucose and other energy sources, and synthesizing and secreting bile acids. Thus, it is well- poised to take advantage of some sensory GPRs to aid in these processes. We recently identified a total of 57 GPRs that are expressed to varying degrees in the murine liver, including 7 with expression profiles that rival other well characterized receptors. One of these high expressing receptors is adhesion receptor GPR125 (ADGRA3). As a family, adhesion receptors have been linked to the maintenance of cell-cell junctions and have been reported to be activated by proteolytically cleavage of their non-covalently attached N-terminal domain. However, GPR125 is an atypical adhesion receptor with a mutated cleavage site and it is unclear if this receptor is activated via the conventional processes. GPR125 has been linked to the development of planar cell polarity in a Zebrafish model suggesting that this receptor may be involved in tissue repair in adult tissues. Using RNAscope and immunofluorescence, we have localized GPR125 to the basolateral membrane of cholangiocytes. Lining the bile ducts, cholangiocytes play a key role in the liver regeneration following injury. Thus, GPR125 is uniquely suited to contribute to this process. We hypothesize that GPR125, on the basolateral membrane of cholangiocytes, is activated by components of the extracellular matrix in order to contribute to liver repair following injury. This will be tested using the PRESTO-TANGO assay to deorphanize the receptor alongside a unique liver-specific knockout mediated by adenoviral delivery of CRISPR guide RNAs. Collectively, our discoveries will unveil new functions for a highly expressing, yet under-characterized, receptor and will set the stage for future physiological analysis in both mouse and man.

项目摘要 G蛋白偶联受体（GPCR）是7个跨膜结构域蛋白，其有助于维持G蛋白偶联受体的功能。 通过对内部和外部环境产生的线索做出反应来保持体内平衡。在人类中， 超过800种已知的GPCR，虽然超过20%的FDA批准的药物靶向GPCR， 这些受体中的大多数都未被充分研究。事实上，许多未被鉴定的孤儿受体， 在不同的组织中以极高的水平表达，这表明它们可能具有 重要但未知的生理功能肝脏是人体内最大的代谢组织 并负责许多重要的功能，包括感应和解毒异生物质， 代谢葡萄糖和其他能量来源，并合成和分泌胆汁酸。因此，这是很好的- 准备利用一些感觉GPR来帮助这些过程。我们最近一共确认了57名 在小鼠肝脏中不同程度表达的GPR，包括7种表达谱与 其他特征良好的受体。这些高表达受体之一是粘附受体GPR 125 （ADGRA3）。作为一个家族，粘附受体与细胞-细胞连接的维持有关， 已报道通过蛋白水解切割它们非共价连接的N-末端 域然而，GPR 125是一种具有突变切割位点的非典型粘附受体， 该受体通过常规方法活化。GPR 125与以下方面的发展有关： 斑马鱼模型中的平面细胞极性表明该受体可能参与成体组织修复 组织中利用RNA显微镜和免疫荧光技术，我们将GPR 125定位于基底外侧膜 胆管细胞胆管细胞排列在胆管中，在以下肝再生中起关键作用： 损伤因此，GPR 125是唯一适合于促进这一过程。我们假设GPR 125，在 胆管细胞的基底外侧膜，被细胞外基质的成分激活， 有助于损伤后的肝脏修复。这将使用PRESTO-TANGO检测试剂盒进行检测， 该受体与由CRISPR引导的腺病毒递送介导的独特的肝脏特异性敲除一起 RNA。总的来说，我们的发现将揭示一个高度表达，但特征不足， 受体，并将为未来的生理分析在小鼠和人的阶段。