Leads and Target Validation for Vascular Calcification in Chronic Kidney Disease

慢性肾病血管钙化的先导物和靶标验证

• 批准号: 7933886
• 负责人: JOSE LUIS MILLAN
• 金额: $ 47.72万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7933886
• 关键词: Address; Aging; Alkaline Phosphatase; Animal Model; Aorta; Area; Arteries; Behavior Therapy; Biological Availability; Cardiovascular system; Cessation of life; Chemicals; Chronic Kidney Failure; Clinical; Clinical Management; Collagen Type I; Culture Media; Data; Diabetes Mellitus; Diphosphates; Disease; Drug Kinetics; Effectiveness; Event; Foundations; Hemodialysis; Hydrolysis; Injection of therapeutic agent; Isoenzymes; Kidney Failure; Laboratories; Lead; Link; Medial; Medical; Metabolic Bone Diseases; Modeling; Morbidity - disease rate; National Institute of Diabetes and Digestive and Kidney Diseases; Obesity; Osteogenesis; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Chemistry; Plasma; Prevention; Property; Public Health; Rattus; Research; Role; Site; Smooth Muscle; Solubility; Structure-Activity Relationship; Testing; Therapeutic; Tissues; Transgenic Mice; Transgenic Organisms; Translating; Translational Research; Up-Regulation; Validation; Vascular Smooth Muscle; Vascular calcification; Viral; base; calcification; drug discovery; extracellular; high throughput screening; improved; in vivo; infancy; inhibitor/antagonist; mortality; mouse model; novel; novel strategies; overexpression; phosphatase inhibitor; prevent; promoter; public health relevance; pyrophosphatase; scaffold; small molecule; therapeutic target

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (15): "Translational Science", and specific Challenge Topic, 15-DK-103: "Translate discovery of new molecules and pathways in pathogenesis of NIDDK diseases into potential therapies". More specifically, this application proposes to validate a therapeutic target and to improve the bioavailability and pharmacokinetic properties of novel small molecule compounds for the prevention and treatment of calcification of the medial layer of arteries, a common and severe condition in patients with chronic kidney disease (CKD), diabetes, obesity and aging that correlates with cardiovascular events and death. To-date there is no effective medical treatment for medial calcification. Research in our laboratories has demonstrated that vascular calcification is normally inhibited by extracellular pyrophosphate (PPi) produced by vascular smooth muscle. Plasma PPi concentrations are reduced in hemodialysis patients and are inversely correlated with vascular calcification. We have shown that levels of PPi are reduced in uremic vascular smooth muscle and that medial calcification in uremic rats and in mouse models of PPi-deficiency is prevented by injections of PPi. The key regulator of extracellular PPi is the ectoenzyme tissue-nonspecific alkaline phosphatase (TNAP) that hydrolyzes PPi, thus destroying its ability to suppress calcification. We have also shown that addition of TNAP to culture medium or overexpression of TNAP by viral transduction causes calcification in cultured aortas and transgenic expression of TNAP in tissues expressing type I collagen is sufficient to cause extraosseous calcification. We have also shown that TNAP is pathophysiologically upregulated at sites of medial calcification in uremic aortas and mouse models of idiopathic infantile arterial calcification, suggesting the putative pathophysiological mechanism that links PPi deficiency to medial calcification in patients with CKD. Using high throughput screening, we have identified potent inhibitors of TNAP that completely prevent calcification of aortas in culture. We hypothesize that medial vascular calcification in renal failure results from increased activity of TNAP in the vasculature and that this ectopic calcification can be prevented by inhibitors of TNAP's pyrophosphatase activity. This RC1 proposal focuses sharply on validating TNAP as a therapeutic target and in improving, via Medicinal Chemistry and structure-activity-relationship studies, the bioavailability and pharmacokinetic properties of novel TNAP inhibitors to enable in vivo testing of the effectiveness of this mechanism-based therapeutic strategy in a uremic rat model of CKD. The clinical management of medial calcification has been limited to minimizing the impact of the associated metabolic bone disease to which it is inextricably linked. This indirect approach has not been very effective in CKD and does not address the calcification that occurs in diabetes or with aging. Thus, there is a need for more specific therapies that directly address the pathogenesis of medial calcification. Pharmacological inhibition of TNAP is a novel approach to this problem that directly addresses the upregulation of TNAP in the vasculature and the ensuing PPi deficiency seen in renal failure. Because TNAP controls extracellular PPi levels under normal conditions this therapy is expected to increase local PPi levels in the vasculature thus inhibiting medial calcification. - Relevance to Public Health Medial calcification of the vasculature is of common occurrence in renal failure, diabetes, obesity and aging, where it contributes to morbidity and mortality through compromised arterial function. Currently there are no treatments for this prevalent condition. Our studies will validate a therapeutic target for medial calcification and will optimize new lead chemicals to prevent/treat arterial calcification in established animal models, thus filling this unmet clinical need. PUBLIC HEALTH RELEVANCE: Medial calcification of the vasculature is of common occurrence in renal failure, diabetes, obesity and aging, where it contributes to morbidity and mortality through compromised arterial function. Currently there are no treatments for this prevalent condition. Our studies will validate a therapeutic target for medial calcification and will optimize new lead chemicals to prevent/treat arterial calcification in established animal models, thus filling this unmet clinical need.

描述(由申请人提供)：本申请涉及广泛的挑战领域(15)：“翻译科学”，以及特定的挑战主题15-DK-103：“将NIDDK疾病发病机制中新分子和途径的发现转化为潜在的治疗方法”。更具体地说，这项申请建议验证一种治疗目标，并提高新型小分子化合物的生物利用度和药代动力学特性，用于预防和治疗动脉中层钙化，这是慢性肾脏疾病(CKD)、糖尿病、肥胖和老龄化患者的一种常见和严重的疾病，与心血管事件和死亡相关。到目前为止，还没有有效的药物治疗内侧钙化。我们实验室的研究表明，血管钙化通常会受到血管平滑肌产生的细胞外焦磷酸(PPI)的抑制。血液透析患者血浆PPI浓度降低，且与血管钙化呈负相关。我们已经证明，尿毒症大鼠和PPI缺乏症小鼠模型注射PPI后，尿毒症大鼠和PPI缺乏症小鼠的血管内膜钙化水平降低。胞外PPI的关键调节因子是胞外酶组织非特异性碱性磷酸酶(TNAP)，它能水解PPI，从而破坏其抑制钙化的能力。我们还发现，在培养上清液中加入TNAP或通过病毒转导过表达TNAP会导致培养的主动脉钙化，而在表达I型胶原的组织中转基因表达TNAP足以引起骨外钙化。我们还发现，在尿毒症大动脉和特发性婴儿动脉钙化的小鼠模型中，TnAP在中层钙化部位的病理生理学上是上调的，提示CKD患者PPI缺乏与中层钙化有关的可能的病理生理学机制。通过高通量筛选，我们已经确定了有效的TNAP抑制剂，可以完全防止培养中的主动脉钙化。我们假设肾功能衰竭的中间血管钙化是由于血管系统中TNAP活性增加所致，并且这种异位钙化可以被TNAP焦磷酸酶活性的抑制剂所阻止。这项RC1提案的重点是验证TNAP作为治疗靶点，并通过药物化学和结构-活性-关系研究改善新型TNAP抑制剂的生物利用度和药代动力学特性，以便能够在尿毒症大鼠CKD模型中测试这一基于机制的治疗策略的有效性。内侧钙化的临床治疗一直局限于最大限度地减少与其密切相关的代谢性骨病的影响。这种间接的方法对慢性肾脏病不是很有效，也不能解决糖尿病或衰老时发生的钙化问题。因此，需要更具体的治疗方法，直接解决内侧钙化的发病机制。对TNAP的药理抑制是解决这一问题的一种新方法，它直接解决了TNAP在血管系统中的上调以及随之而来的肾衰竭中出现的PPI缺陷。由于在正常情况下，TNAP可控制细胞外PPI水平，因此该疗法有望提高血管内局部PPI水平，从而抑制中层钙化。-与公共卫生相关血管内侧钙化在肾衰竭、糖尿病、肥胖和老龄化中常见，它通过损害动脉功能而导致发病率和死亡率。目前还没有针对这种流行疾病的治疗方法。我们的研究将验证内侧钙化的治疗目标，并将优化新的铅化学物质，以在已建立的动物模型中预防/治疗动脉钙化，从而填补这一未得到满足的临床需求。 公共卫生相关性：血管内侧钙化在肾功能衰竭、糖尿病、肥胖和衰老中常见，它通过损害动脉功能而导致发病率和死亡率。目前还没有针对这种流行疾病的治疗方法。我们的研究将验证内侧钙化的治疗目标，并将优化新的铅化学物质，以在已建立的动物模型中预防/治疗动脉钙化，从而填补这一未得到满足的临床需求。