Elucidation of Beta-2 Adrenergic Receptor Pathways Leading to Mitochondrial Biogenesis

阐明导致线粒体生物发生的 Beta-2 肾上腺素受体途径

• 批准号: 9349493
• 负责人: Robert Bruce Cameron
• 金额: $ 4.64万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2019-07-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9349493
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Address; Adrenergic Agonists; Adrenergic Receptor; Adverse effects; Affect; Affinity; Agonist; Biogenesis; Cell Respiration; Cells; Cyclic GMP; Data; Development; Drug Exposure; Drug usage; Event; Exhibits; Exposure to; Failure; Gases; Generations; Goals; Immunoblot Analysis; Impairment; In Vitro; Injury; Intervention; Knockout Mice; Laboratories; Lead; Mitochondria; Mitochondrial Proteins; Molecular Conformation; Morbidity - disease rate; Onset of illness; Organ; Organ failure; Oxidative Stress; PPAR gamma; Pathologic; Pathway interactions; Patients; Pharmacology; Phosphorylation Site; Process; Production; Proximal Kidney Tubules; Receptor Signaling; Recovery; Renal function; Reperfusion Injury; Role; Signal Pathway; Signal Transduction; Site-Directed Mutagenesis; Small Interfering RNA; Tissues; Toxicant exposure; beta-2 Adrenergic Receptors; cGMP production; design; effective therapy; in vivo; in vivo Model; inhibitor/antagonist; injured; mitochondrial dysfunction; mortality; novel; novel therapeutic intervention; novel therapeutics; public health relevance; receptor; renal ischemia; repaired; restoration

DESCRIPTION (provided by applicant): Acute kidney injury (AKI) is a severe, rapid-onset disease characterized by a rapid loss in renal function leading to substantial morbidity and mortality. Frequent causes of AKI include ischemia/reperfusion (I/R) injury and acute drug or toxicant exposure. Despite attempts to develop new therapeutic strategies to treat AKI, few have been successful, and mortality has remained unchanged for several decades. Therefore, novel targets must be examined for the development of useful therapies for AKI. It has been shown that renal proximal tubule cells exhibit severe mitochondrial dysfunction and depletion of mitochondrial proteins following toxicant exposure or I/R injury. Mitochondrial dysfunction leads to oxidative stress and persistent energy depletion, which exacerbates injury and impairs energy-dependent repair, leading to end organ damage and failure in a variety of tissues. Our laboratory has demonstrated that injured renal proximal tubules can recover if they are induced to generate new mitochondria through mitochondrial biogenesis (MB). In addition, our laboratory has identified several compounds capable of inducing MB in vitro and in in vivo models of AKI. Among these compounds are several b2 adrenergic receptor (b2AR) agonists; however, not all b2AR agonists were found to induce MB. The capacity of these compounds to induce MB biogenesis did not correlate with affinity, but did correlate with the capacity of these compounds to increase levels of cGMP. In turn, cGMP has been shown to induce MB by increasing the activity of peroxisome proliferator-activated receptor gamma coactivator-1a (PGC1a), the master regulator of MB. We hypothesize that biogenic b2AR agonists stimulate MB and promote recovery of renal function by inducing a specific receptor conformation that leads to the production of cGMP. This hypothesis will be addressed through the following Specific Aims. Aim 1 will determine the effects of mitochondrial biogenic agonists-induced effects on the b2AR that lead to a biogenic conformation. Site-directed mutagenesis and immunoblot analysis will identify b2AR phosphorylation sites required for the induction of MB. Aim 2 will elucidate the role of Gas- and Gai-dependent signaling pathways in the generation of cGMP and the induction of MB. Pharmacologic inhibitors and siRNA will identify the relevant signaling pathways for the induction of MB. Non-MB b2AR agonists will be used as controls. Aim 3 will determine the b2AR signaling pathways found in Aims 1 and 2 in the recovery of renal function following I/R injury using b2AR KO mice and pharmacological inhibitors. These results will further support the approach of using drugs that induce MB to accelerate recovery of renal function after AKI.

描述（由申请人提供）：急性肾脏损伤（AKI）是一种严重的快速发作的疾病，其特征是肾功能迅速丧失，导致大量发病和死亡率。 AKI经常出现的原因包括缺血/再灌注（I/R）损伤和急性药物或毒性暴露。尽管试图制定新的治疗策略来治疗AKI，但很少有成功，而且死亡率一直保持不变数十年。因此，必须检查新的靶标，以开发AKI有用的疗法。已经表明，肾近端小管细胞表现出严重的线粒体功能障碍和毒性暴露后的线粒体蛋白或I/R损伤后的线粒体蛋白的耗竭。线粒体功能障碍会导致氧化应激和持续的能量消耗，从而加剧了损伤并损害能量依赖性修复，从而导致各种组织中的最终器官损伤和失败。我们的实验室表明，如果受伤的肾近端小管被诱导通过线粒体生物发生（MB）产生新的线粒体，则可以恢复。此外，我们的实验室已经确定了几种能够在体外和体内AKI模型中诱导MB的化合物。其中包括几种B2肾上腺素能受体（B2AR）激动剂。但是，并非所有B2AR激动剂都诱导MB。这些化合物诱导MB生物发生的能力与亲和力无关，而是与这些化合物增加CGMP水平的能力相关。反过来，CGMP已被证明通过增加过氧化物酶体增殖物激活的受体伽马共振剂1A（PGC1A）（MB的主调节剂）的活性来诱导MB。我们假设生物B2AR激动剂通过诱导特定的受体构象刺激MB并促进肾功能的恢复，从而导致CGMP产生。该假设将通过以下特定目的解决。 AIM 1将确定线粒体生物生物激动剂对B2AR的影响的影响，从而导致生物构象。位置定向的诱变和免疫印迹分析将确定诱导MB所需的B2AR磷酸化位点。 AIM 2将阐明气体和GAI依赖性信号通路在CGMP产生和MB诱导中的作用。药理抑制剂和siRNA将识别诱导MB的相关信号通路。非MB B2AR激动剂将用作对照。 AIM 3将通过B2AR KO小鼠和药理抑制剂在I/R损伤后恢复AIM 1和2中发现的B2AR信号通路。这些结果将进一步支持使用诱导MB加速AKI后肾功能恢复的药物的方法。