Reno-protection afforded by combinatory approach targeting AT2R and neprilysin in obesity

针对肥胖症中 AT2R 和脑啡肽酶的组合方法提供的 Reno 保护

• 批准号: 9911358
• 负责人: Elizabeth Gray
• 金额: $ 3.42万
• 依托单位: UNIVERSITY OF HOUSTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-12 至 2022-09-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9911358
• 关键词: Accreditation; Agonist; Albumins; Albuminuria; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Atrial Natriuretic Factor; Attenuated; Binding; Biochemical; Biological; Blood Pressure; Blood Pressure Monitors; Cardiovascular Physiology; Cardiovascular system; Chronic; Clinical; Combined Modality Therapy; Comorbidity; Creatinine; Data; Diabetes Mellitus; Diet; EFRAC; Enalapril; Female; Future; Glomerular Filtration Rate; Heart failure; Histologic; Hypertension; Impairment; In Vitro; Incubated; Individual; Injury; Kidney; Knowledge; Laboratories; Liquid Chromatography; Mediating; Messenger RNA; Metabolism; Metalloproteases; Methods; Monitor; Natriuresis; Natriuretic Peptides; Neprilysin; Obesity; Obesity Related Hypertension; Outcome; Pathologic; Pathology; Peptide Metabolism; Peptide Receptor; Peptides; Peptidyl-Dipeptidase A; Periodic acid Schiff stain method; Pharmaceutical Preparations; Plasma; Prevalence; Process; Production; Proteins; Proteinuria; Public Health; Publishing; Rattus; Receptor, Angiotensin, Type 1; Renal function; Renin; Renin-Angiotensin System; Reporting; Research Project Grants; Risk; Risk Factors; Site; Sodium; Sodium Chloride; Stable Isotope Labeling; Stains; Structure; Suspensions; Telemetry; Testing; Therapeutic; Thinness; Type 2 Angiotensin II Receptor; Vasodilation; Work; Zucker Rats; hemodynamics; high salt diet; improved; inhibitor/antagonist; kidney cortex; kidney dysfunction; male; novel; novel strategies; novel therapeutics; obesity treatment; pre-doctoral; pressure; receptor; receptor expression; response; salt sensitive hypertension; sex; tandem mass spectrometry; treatment duration; urinary; valsartan

Abstract The increasing world-wide prevalence of obesity is a worrying public health problem and crisis. Coexistence of obesity, hypertension and diabetes significantly increases the risk of kidney dysfunction. In obesity, concentrations of angiotensin II (Ang II) increase, while those of Ang-(1-7) decrease along with activity of angiotensin converting enzyme 2 (ACE2). Neprilysin (NEP) and ACE2 are metallopeptidases that process Ang I and Ang II, respectively into the Mas receptor agonist, Ang-(1-7). The activity of these protective renin angiotensin system (RAS) components counterbalances the detrimental biological effects of the classical Ang II/angiotensin II type 1 receptor (AT1R) RAS axis. Recently published and preliminary data from our laboratory suggests that treatment with AT2R agonist compound 21 (C21) decreases Ang II and increases Ang-(1-7) in the kidney of obese Zucker rats, by increasing expression and activity of ACE2. Furthermore, our in vitro data suggests that AT2R agonist treatment decreases renin activity as well. Entresto, a dual AT1R blocker (valsartan) and neprilysin inhibitor (sacubitril) recently released to the market was found to be superior to enalapril therapy alone in the PARADIGM HF trial, resulting in its indication for heart failure with reduced ejection fraction. The benefits of Entresto are accredited to its ability to increase concentrations of atrial natriuretic peptide (ANP), another substrate of NEP, while blocking the increasing concentrations of Ang II from acting on AT1R. Yet, Entresto was found to cause an increase in the urinary albumin/creatinine ratio, an indicator of kidney injury. This knowledge along with our preliminary results led to our hypothesis that Ang-(1-7) level in obese kidney is decreased by NEP inhibition, with concurrent increase in Ang II. Combination therapy with C21 increases Ang- (1-7) and attenuates Ang II, by increasing ACE2 activity and expression. Moreover, C21 with NEP inhibition produces an additive effect on increasing ANP levels in obese kidney protecting function and structural integrity of the kidney. To test this hypothesis, Aim 1 is directed to determine the basal levels and basic metabolism of Ang peptides and ANP in obese kidney. Aim 2 will determine that combined treatment (short-term) with NEP inhibitor and AT2R agonist enhances ACE2 activity and Ang-(1-7) levels, and attenuates Ang II levels and ANP degradation in obesity. Aim 3 will determine that chronic combination therapy with a NEP inhibitor and AT2R agonist is reno-protective in salt-induced hypertension in obesity and is superior to Entresto (ARB + NEP inhibitor). Female obese Zucker rats are included in aim 3 to investigate the sex specific outcomes of our novel combinatory approach and to determine if it is equally effective in both male and female obese Zucker rats. To accomplish these aims, Ang peptides will be quantified utilizing our new liquid chromatography tandem mass spectrometry method; biochemical, histological and hemodynamic approaches to study renal function/injury and telemetry for monitoring blood pressure. The proposed work will significantly contribute to understanding Ang metabolism in obesity and impact future clinical perspectives for a novel reno-protective therapeutic approach.

摘要 肥胖在世界范围内日益普遍，这是一个令人担忧的公共卫生问题和危机。两个国家共存 肥胖、高血压和糖尿病会显著增加患肾功能障碍的风险。在肥胖方面， 血管紧张素II(Ang II)浓度随血管紧张素Ⅱ(Ang II)活性的升高而升高，而Ang-(1-7)浓度随血管紧张素II活性的升高而降低 血管紧张素转换酶2(ACE2)。Neprilysin(NEP)和ACE2是加工血管紧张素的金属多肽酶 I和II分别转化为Mas受体激动剂Ang-(1-7)。这些保护性肾素的活性 血管紧张素系统(RAS)组分抵消经典血管紧张素转换酶(ANG)的有害生物学效应 血管紧张素II/血管紧张素Ⅱ1型受体(AT1R)RAS轴。最近发表的和我们实验室的初步数据 提示用AT2R激动剂化合物21(C21)治疗可减少血管紧张素Ⅱ，增加血管紧张素Ⅱ-(1-7)。 通过增加ACE2的表达和活性来改善肥胖的Zucker大鼠的肾脏。此外，我们的体外数据 提示AT2R激动剂治疗也会降低肾素活性。双AT1R阻滞剂Entresto(Valsartan) 最近上市的奈普利辛抑制剂(萨舒比利)被发现优于依那普利疗法。 在范式心力衰竭试验中单独使用，导致其心力衰竭的指征和降低的射血分数。这个 Entresto的好处被认为是它能够增加心钠素的浓度， NEP的另一种底物，同时阻断不断增加的Ang II对AT1R的作用。然而， Entresto被发现导致尿白蛋白/肌酐比值增加，这是肾脏损伤的一个指标。 这一知识与我们的初步结果一起导致了我们的假设，即肥胖肾脏中的Ang-(1-7)水平 NEP抑制后降低，Ang II同时升高。C21联合治疗可增加Ang。 (1-7)，并通过增加血管紧张素转换酶2的活性和表达来减弱血管紧张素Ⅱ。此外，C21还具有NEP抑制作用 在肥胖的肾脏保护功能和结构完整性中产生增加ANP水平的相加效应 肾脏的组织结构。为了验证这一假设，目标1旨在确定基础水平和基础代谢。 肥胖肾脏组织中ANG多肽和ANP的变化。目标2将确定NEP的联合治疗(短期) 抑制剂和AT2R激动剂提高ACE2活性和Ang-(1-7)水平，降低Ang II和ANP水平 肥胖症的退化。目标3将确定NEP抑制剂和AT2R的慢性联合治疗 激动剂对盐诱导的肥胖性高血压有肾保护作用，优于Entresto(Arb+NEP 抑制物)。雌性肥胖的Zucker大鼠被包括在目标3中，以调查我们新发现的性别特定的结果 并确定其对肥胖的雄性和雌性Zucker大鼠是否同样有效。至 为了实现这些目标，ANG多肽将利用我们新的高效液相色谱串联质谱仪进行定量 光谱学方法；生化、组织学和血流动力学方法研究肾功能/损伤和 用于监测血压的遥测技术。拟议的工作将大大有助于理解和 肥胖症的代谢和影响肾脏保护性治疗新方法的未来临床前景。