Role of PON3 in regulating renal Na+ and K+ homeostasis

PON3 在调节肾钠钾稳态中的作用

• 批准号: 10693407
• 负责人: Shujie Shi
• 金额: $ 31.8万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10693407
• 关键词: Address; Affect; Aldosterone; Amiloride; Apical; Arylesterase; Biological Models; Biotinylation; Blood; Blood Pressure; Caenorhabditis elegans; Cell Line; Cells; Data; Diet; Dietary Potassium; Distal; Distal convoluted renal tubule structure; Duct (organ) structure; Endoplasmic Reticulum; Extracellular Fluid; Family; Genetic Transcription; Homeostasis; Hypertension; Hypokalemia; Hypotensives; Immunofluorescence Immunologic; Intake; Intercalated Cell; Ion Channel; Kidney; Knockout Mice; Measures; Mediating; Metabolic; Molecular Chaperones; Monitor; Mus; Natriuresis; Nephrons; Neurons; Patch-Clamp Techniques; Pathway interactions; Pattern; Phosphorylation; Physiological; Potassium; Potassium Channel; Property; Proteins; Publishing; Radio; Rattus; Regional Perfusion; Regulation; Renal function; Role; SLC12A3 gene; Side; Sodium; Sodium Chloride; Stains; Substrate Specificity; Surface; Telemetry; Tissues; Touch sensation; Ubiquitination; Water; Western Blotting; Work; absorption; aryldialkylphosphatase; blood pressure control; blood pressure regulation; cell type; dietary salt; differential expression; driving force; epithelial Na+ channel; extracellular; hyperkalemia; in vivo; large-conductance calcium-activated potassium channels; member; multicatalytic endopeptidase complex; new therapeutic target; novel; receptor; symporter

ABSTRACT The mammalian paraoxonase (PON) family consists of three highly conserved members (PON1, PON2 and PON3) with unique anti-oxidative and anti-atherosclerotic properties. PON1 and 2 have been implicated in blood pressure (BP) regulation. While the role of PON3 in regulating BP has not been investigated, it is expressed in the aldosterone-sensitive distal nephron where the fine tuning of Na+ absorption and K+ secretion occurs. PONs share key structural and functional features with MEC-6, an endoplasmic reticulum-resident chaperone of C. elegans. MEC-6 is required for proper folding, assembly, and surface expression of the mechanosensitive degenerin channel in touch receptor neurons. The chaperon function is conserved between mammalian PONs and C. elegans MEC-6. We have previously shown that both PON2 and PON3 regulate functional expression of the epithelial Na+ channel (ENaC), a member of the ENaC/degenerin family of ion channels. ENaC mediates the rate-limiting step of Na+ reabsorption in distal nephron and has a key role in volume and BP control. While the constitutive K+ secretion is conducted by the renal outer medullary K+ (ROMK) channels, ENaC-dependent and flow-induced K+ secretion is mediated by the large conductance K+ (BK) channels. In the preliminary studies, we found that Pon3 KO mice have higher ENaC activity and enhanced amiloride-sensitive natriuresis, suggesting ENaC functional expression is upregulated in the absence of PON3. In addition, we have identified BK channel as a novel target of PON3. When expressed in HEK293 cells, PON3 interacted with BK α subunit to reduce its surface expression and channel activity. Our proposed studies will define mechanisms by which PON3 functions as a chaperone in the regulation of ENaC and BK expression. We will determine the consequences of deleting PON3 in renal Na+ and K+ handling and BP control in mice. Successful completion our proposed studies will enhance our understanding of the mechanisms by which PONs function as chaperones and their physiological roles in kidney function and BP control.

抽象的 哺乳动物甲氧酮酶（PON）家族由三个高度保守的成员组成（PON1， PON2和PON3）具有独特的抗氧化和抗动脉粥样硬化特性。 PON1和2 在血压（BP）调节中隐含。而PON3在调节BP中的作用 尚未研究，它在醛固酮敏感的远端肾单位中表达 进行Na+受损和K+分泌的微调。 PON具有关键结构和功能 MEC-6的特征是秀丽隐杆线虫的内质网居住伴侣。 MEC-6是 适当的折叠，组装和表面表达机械敏感性脱脂蛋白所必需 接触受体神经元的通道。伴侣功能是在哺乳动物之间保守的 POS和C.秀丽隐杆线MEC-6。我们以前已经表明PON2和PON3都调节 上皮Na+通道（ENAC）的功能表达，ENAC/Degenerin的成员 离子频道家族。 ENAC介导了远端肾单位中Na+重吸收的速率限制步骤 并在体积和BP控制中具有关键作用。而本构的K+分泌是由 肾外髓K+（romk）通道，依赖于ENAC和流动诱导的K+分泌 由大电导K+（BK）通道介导。在初步研究中，我们发现 PON3 KO小鼠具有较高的ENAC活性，并增强了氨基氨基敏感性的Natriuresis， 在没有PON3的情况下，建议更新ENAC功能表达。另外，我们 已经将BK通道确定为PON3的新靶标。当在HEK293细胞中表达时，PON3 与BKα亚基相互作用，以减少其表面表达和通道活性。我们提出的 研究将定义PON3在调节中作为伴侣的机制 ENAC和BK表达。我们将确定在肾脏Na+中删除PON3的后果 小鼠中的K+处理和BP对照。成功完成我们建议的研究将增强 我们对PON充当伴侣及其作用机制及其的理解 生理作用在肾功能和BP控制中。