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.

肾小球足细胞在包括糖尿病（糖尿病）的肾小球疾病的发病机理中起关键作用 肾病（DN）。积累的证据表明，CGMP信号在 肾脏疾病。一氧化氮（NO）和亚钠肽（NP）刺激CGMP的产生 心房NP（ANP），脑NP（BNP）和C型NP（CNP）。在足细胞中，CGMP生成有效刺激 由NPS。相比之下，足细胞对NO的响应最小。因此，NP是主要的源CGMP 足细胞产生。 NP通过与NP受体（NPRS）NPRA结合而诱导CGMP生成（结合 ANP和BNP）和NPRB（结合CNP）。 NP动作的重要调节因子是NP清除受体 （NPRC），结合并降解ANP，BNP和CNP。 NPRC的药物阻滞抑制结合 NPS到NPRC，它增强了NPRA和NPRB诱导的CGMP生成。而且，NP有直接 体内的足细胞保护作用是因为ANP受体（NPRA）的Podocyte特异性敲除（KO） 在蛋白尿小鼠模型中增强肾小球损伤。我们的初步研究发现：1。 Express NPRA，NPRB和NPRC。 2。NPRC在足细胞中高度表达，并显着限制CGMP 通过本地可用的NP生成。 3。ANP和CNP均保护足细胞免受凋亡刺激，4。 NPRC的Podocyte特异性敲除（KO）减少了1型糖尿病（Akita小鼠）模型中的蛋白尿，5。 NPRC的药理阻滞有效地促进了体外和体内的Podocyte保护性CGMP生成 和6。NPRC的药理学阻滞减少了Akita小鼠的蛋白尿。基于这些观察， 我们假设NPRC对NP的清除率将增强局部NP水平，促进podocyte 保护性CGMP信号传导和改善DKD。提出了两个具体目标。 AIM 1：检查DKD中的Podocyte特异性NPRC KO。这些研究将专门在 足细胞。 Subaim 1A将研究Akita小鼠中的NPRC KO。 Subaim 1B将补充Subaim 1A 通过研究患有既定疾病的Akita小鼠中的诱导NPRC KO。足细胞保护机制 NP信号将在KO和野生型小鼠（WT）的肾脏以及培养的足细胞中进行研究。 AIM 2：检查Akita小鼠中NPRC的药理阻滞。 AIM 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，并且在 转弯，增强NP的效果。然后，我们将研究NPRC封锁在Akita小鼠中的影响。 Subaim 2a 将确定最有效的进一步研究药物（概念证明）。 Subaim 2b将使用 已建立的疾病。因此，这些研究检查了治疗方法的翻译潜力。