5-HT Stimulation of Mitochondrial Biogenesis and Acute Kidney Injury

项目总结/摘要 急性肾损伤（阿基）是一种死亡率高且无治疗的毁灭性疾病。常见原因 包括败血症、创伤、药物/毒物暴露和缺血/再灌注 （IR）。我们实验室的长期目标是揭示阿基的新机制，并开发治疗方法， 促进复苏。在阿基之后，观察到肾微血管系统的显著减少，并导致 组织修复所需的氧气和营养物质流失到血管外组织。此外，还有持续 阿基后的线粒体功能障碍。介导血管修复和线粒体生物发生的途径（MB） 都被忽视了我们先前证实了5-HT 1F受体存在于肾近端小管细胞 （RPTC），并确定了5-HT 1F受体介导的MB的途径。5-HT 1F受体敲除小鼠 IR诱导的阿基后肾脏线粒体稳态改变和肾脏恢复受损，而5-HT 1F 受体激动剂lasmiditan刺激MB并改善肾恢复。 与RPTC不同，内皮细胞（EC）主要通过有氧糖酵解获得能量， 线粒体和氧化磷酸化。通过EC中的5-HT 1F受体刺激MB可能促进 阿基后血管恢复。我们的初步数据显示：（i）小鼠肾管周原代培养物， 内皮细胞（MRPEC）表达5-HT 1F受体，（ii）用拉米替坦处理MRPEC诱导MB， 增加线粒体功能，（iii）lasmiditan刺激MRPEC分支和伤口闭合，（iv）lasmiditan 刺激小鼠EC中的MB，（v）lasmiditan减少血管渗漏并改善肾恢复，（vi）小鼠 缺乏5-HT 1F受体的人肾血管减少，和（vii）拉西米坦不会诱导肾MB， 缺乏5-HT 1F受体的小鼠。因此，我们以前和目前的工作表明，5-HT 1F受体的作用， 刺激AKI后EC中MB和血管生成。 我们假设最近FDA批准的药物lasmiditan诱导5-HT 1F受体活化 肾血管内皮促进MB和血管生成，导致血管稀疏减少， 增加血管功能和促进肾从阿基中恢复。 我们将通过以下具体目标来检验这一假设。目的1将确定5-HT 1F受体 对5-HT 1F受体激动剂lasmiditan应答的负责MB和血管生成的信号通路 在MRPEC。目的2将确定常氧、氧化剂暴露和促炎条件对 MB和血管生成，并阐明lasmiditan恢复线粒体功能的疗效和机制 和MRPEC中的血管生成。目的3：研究EC和RPTC中5-HT 1F受体表达在E. coli中的作用。 IR损伤阿基后，在存在和不存在lasmiditan的情况下血管和肾脏恢复。

PROJECT SUMMARY/ABSTRACT Acute Kidney Injury (AKI) is a devastating disease with high mortality and no treatments. Common causes of AKI in the VETERAN population include sepsis, trauma, drug/toxicant exposure, and ischemia/reperfusion (IR). The long-term goal of our laboratory is to uncover novel mechanisms of AKI and develop therapeutics to promote recovery. Following AKI, a marked reduction in renal microvasculature is observed and results in the loss of oxygen and nutrients to extravascular tissue needed for tissue repair. In addition, there is persistent mitochondrial dysfunction following AKI. Pathways mediating vascular repair and mitochondrial biogenesis (MB) are under-studied. We previously confirmed the presence of the 5-HT1F receptor in renal proximal tubular cells (RPTC) and identified the pathways of 5-HT1F receptor-mediated MB. The 5-HT1F receptor knockout mouse has altered renal mitochondrial homeostasis and impaired renal recovery following IR-induced AKI, while the 5-HT1F receptor agonist lasmiditan stimulated MB and improved renal recovery. Unlike RPTC, endothelial cells (EC) primarily derive their energy through aerobic glycolysis with limited mitochondria and oxidative phosphorylation. Stimulation of MB via the 5-HT1F receptor in EC may promote vascular recovery following AKI. Our preliminary data reveal that (i) primary cultures of mouse renal peritubular endothelial cells (MRPEC) express the 5-HT1F receptor, (ii) treatment of MRPEC with lasmiditan induces MB and increases mitochondrial function, (iii) lasmiditan stimulates MRPEC branching and wound closure, (iv) lasmiditan stimulates MB in EC in mice, (v) lasmiditan decreases vascular leakage and improves renal recovery, (vi) mice lacking the 5-HT1F receptor have decreased renal vasculature, and (vii) lasmiditan does not induce renal MB in mice lacking the 5-HT1F receptor. Thus, our previous and current work suggest a role for the 5-HT1F receptor in stimulating MB and angiogenesis in EC followingAKI. We hypothesize that lasmiditan, a recently FDA-approved drug, induced activation of the 5-HT1F receptor in renal vascular endothelium promotes MB and angiogenesis, resulting in decreased vascular rarefication, increased vascular function, and promotion of renal recovery from AKI. We will test this hypothesis with the following specific aims. Aim 1 will determine the 5-HT1F receptor signaling pathway(s) responsible for MB and angiogenesis in response to the 5-HT1F receptor agonist lasmiditan in MRPEC. Aim 2 will determine the effects of normoxia, oxidant exposure, and pro-inflammatory conditions on MB and angiogenesis, and elucidate the efficacy and mechanism of lasmiditan in restoring mitochondrial function and angiogenesis in MRPEC. Aim 3 will determine the role of 5-HT1F receptor expression in EC and RPTC in vascular and renal recovery in the presence and absence of lasmiditan following IR injury AKI.