Promoting podocyte protective cGMP signaling in diabetic kidney disease

促进糖尿病肾病中足细胞保护性 cGMP 信号传导

• 批准号: 10588751
• 负责人: Robert Spurney
• 金额: --
• 依托单位: DURHAM VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10588751
• 关键词: Albuminuria; Apoptotic; Atrial Natriuretic Factor; Atrial Natriuretic Factor Receptors; Binding; Brain natriuretic peptide; C-Type Natriuretic Peptide; Complement; Cyclic GMP; Cytoprotection; Diabetic Nephropathy; Disease; Economic Burden; Endocrine system; Generations; Goals; Healthcare Systems; Human; In Vitro; Injury; Insulin-Dependent Diabetes Mellitus; Kidney; Kidney Diseases; Kidney Failure; Knock-out; Knockout Mice; Medical; Modeling; Mus; NPR2 gene; Natriuretic Peptides; Nitric Oxide; Nitric Oxide Synthase Type I; Pathogenesis; Peptide Receptor; Peptide Signal Sequences; Pharmaceutical Preparations; Play; Receptor Inhibition; Renal glomerular disease; Role; Signal Transduction; Source; Stimulus; United States; Wild Type Mouse; cost; in vivo; mouse model; peptide analog; pharmacologic; podocyte; prevent; protective effect; receptor; translational potential

Glomerular podocytes play a pivotal role in the pathogenesis of glomerular diseases including diabetic nephropathy(DN). Accumulating evidence suggests that cGMP signaling has podocyte protective effects in kidney diseases. Generation of cGMP is stimulated by nitric oxide (NO) and natriuretic peptides (NPs) such as atrial NP (ANP), brain NP (BNP) and C-type NP (CNP). In podocytes, cGMP generation is potently stimulated by NPs. In contrast, podocytes are minimally responsive to NO. Thus, NPs are the predominant source cGMP generation in podocytes. NPs induce cGMP generation by binding to the NP receptors (NPRs) NPRA (binds ANP and BNP) and NPRB (binds CNP). An important regulator of NP actions is the NP clearance receptor (NPRC), which binds and degrades ANP, BNP and CNP. Pharmacologic blockade of NPRC inhibits binding of NPs to NPRC, which potentiates NPRA- and NPRB-induced cGMP generation. Moreover, NPs have direct podocyte protective actions in vivo because podocyte specific knockout (KO) of the ANP receptor (NPRA) augments glomerular injury in a proteinuric mouse model. Our preliminary studies found that: 1. Podocytes express NPRA, NPRB and NPRC. 2. NPRC is highly expressed in podocytes and significantly limits cGMP generation by locally available NPs. 3. Both ANP and CNP protect podocytes from apoptotic stimuli, 4. Podocyte specific knockout (KO) of NPRC reduces albuminuria in a model of type 1 diabetes (Akita mice), 5. Pharmacologic blockade of NPRC potently promotes podocyte protective cGMP generation in vitro and in vivo, and 6. Pharmacologic blockade of NPRC decreases albuminuria in Akita mice. Based on these observations, we hypothesized that blocking clearance of NPs by NPRC will enhance local NP levels, promote podocyte protective cGMP signaling and ameliorate DKD. Two specific aims are proposed. Aim 1: Examine podocyte specific NPRC KO in DKD. These studies will KO NPRC specifically in podocytes. Subaim 1A will study constitutive NPRC KO in Akita mice. Subaim 1B will complement subaim 1A by studying inducible NPRC KO in Akita mice with established disease. Podocyte protective mechanisms of NP signaling will be studied in kidneys of KO and wild type mice (WT), and in cultured podocytes. Aim 2: Examine pharmacologic blockade of NPRC in Akita mice. Aim 2 will use the ANP analogs ANP(4- 23) and AP811to inhibit NP clearance by specifically binding to NPRC without binding NPRA or NPRB and, in turn, enhance the effects of NPs. We will then study the effects of NPRC blockade in Akita mice. Subaim 2A will determine the most effective drug for further study (proof of concept). Subaim 2B will study Akita mice with established disease. Thus, these studies examine the translational potential of the treatment approach.

肾小球足细胞在糖尿病等肾小球疾病的发病机制中发挥着关键作用 肾病（DN）。越来越多的证据表明 cGMP 信号对足细胞具有保护作用 肾脏疾病。一氧化氮 (NO) 和利尿钠肽 (NP) 会刺激 cGMP 的生成，例如 心房NP（ANP）、脑NP（BNP）和C型NP（CNP）。在足细胞中，cGMP 的生成受到强烈刺激 通过 NP。相反，足细胞对 NO 的反应最低。因此，NP 是 cGMP 的主要来源 足细胞的产生。 NP 通过与 NP 受体 (NPR) 结合来诱导 cGMP 生成 NPRA（结合 ANP 和 BNP）和 NPRB（结合 CNP）。 NP 作用的重要调节者是 NP 清除受体 (NPRC)，结合并降解 ANP、BNP 和 CNP。 NPRC 的药理学阻断可抑制 NPRC 的结合 NP 转化为 NPRC，增强 NPRA 和 NPRB 诱导的 cGMP 生成。此外，NP 具有直接 由于 ANP 受体 (NPRA) 足细胞特异性敲除 (KO)，足细胞在体内具有保护作用 增强蛋白尿小鼠模型中的肾小球损伤。我们的初步研究发现： 1.足细胞 表达 NPRA、NPRB 和 NPRC。 2. NPRC在足细胞中高表达并显着限制cGMP 由本地可用的 NP 生成。 3. ANP 和 CNP 都能保护足细胞免受凋亡刺激，4. NPRC 足细胞特异性敲除 (KO) 可减少 1 型糖尿病模型（秋田小鼠）中的蛋白尿，5。 NPRC 的药理学阻断可有效促进体外和体内足细胞保护性 cGMP 的产生， 6. NPRC 的药物阻断可减少秋田小鼠的蛋白尿。根据这些观察， 我们假设通过 NPRC 阻断 NP 的清除将提高局部 NP 水平，促进足细胞 保护性 cGMP 信号传导并改善 DKD。提出了两个具体目标。 目标 1：检查 DKD 中足细胞特异性 NPRC KO。这些研究将特别针对 NPRC 足细胞。 Subaim 1A 将研究秋田小鼠中的组成型 NPRC KO。 Subaim 1B 将补充 subaim 1A 通过研究患有已知疾病的秋田小鼠的诱导型 NPRC KO。足细胞的保护机制 将在 KO 和野生型小鼠 (WT) 的肾脏以及培养的足细胞中研究 NP 信号传导。 目标 2：检查秋田小鼠中 NPRC 的药理学阻断作用。目标 2 将使用 ANP 类似物 ANP(4- 23) 和 AP811 通过特异性结合 NPRC 而不结合 NPRA 或 NPRB 来抑制 NP 清除，并且， 反过来，增强NPs的效果。然后我们将研究 NPRC 阻断对秋田小鼠的影响。苏拜姆2A 将确定最有效的药物进行进一步研究（概念验证）。 Subaim 2B 将研究秋田小鼠 既定的疾病。因此，这些研究检验了治疗方法的转化潜力。