5-HT Stimulation of Mitochondrial Biogenesis and Acute Kidney Injury

项目摘要/摘要 急性肾损伤(AKI)是一种死亡率高、无治疗方法的破坏性疾病。常见原因 退伍军人AKI的病因包括败血症、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发现AKI的新机制，并开发治疗方法 促进经济复苏。AKI后，肾微血管明显减少，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，还有持之以恒的 急性心肌梗死后线粒体功能障碍。介导血管修复和线粒体生物发生的途径(MB) 都没有得到充分的研究。我们先前证实了肾近端小管细胞中存在5-HT1F受体。 (RPTC)，并确定了5-HT1F受体介导MB的途径。5-HT1F受体基因敲除小鼠 IR诱导AKI后肾脏线粒体动态平衡的改变和肾脏恢复的损害，而5-HT1F 受体激动剂Lasmiditan刺激MB，改善肾脏恢复。 与RPTC不同，内皮细胞(EC)主要通过有氧糖酵解获得能量，但有限 线粒体和氧化磷酸化。通过5-HT1F受体刺激内皮细胞MB可能促进 AKI后血管恢复。我们的初步数据显示：(1)小鼠肾小管周围的原代培养 血管内皮细胞(MRPEC)表达5-HT1F受体，(Ii)雷米坦处理MRPEC诱导MB和 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脏恢复，(Vi)小鼠 缺乏5-HT1F受体使肾血管减少，并且(Vii)拉米坦不能诱导肾MB。 缺乏5-HT1F受体的小鼠。因此，我们以前和现在的工作表明5-HT1F受体在 刺激AKI后EC的MB和血管生成。 我们假设最近FDA批准的药物Lasmiditan诱导了5-HT1F受体的激活 在肾血管内皮细胞促进MB和血管生成，导致血管稀疏减少， 增强血管功能，促进急性肾损伤后肾功能恢复。 我们将通过以下具体目标来检验这一假设。AIM 1将确定5-HT1F受体 5-HT1F受体激动剂Lasmiditan对MB和血管生成的信号转导(S) 在MRPEC。目的2将确定常氧、氧化剂暴露和促炎条件对 MB与血管生成的关系，阐明拉司米坦恢复线粒体功能的作用及机制 和MRPEC的血管生成。AIM 3将确定5-HT1F受体在EC和RPTC中的表达 IR损伤后存在和不存在拉米坦时的血管和肾脏恢复。

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.