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Serotonin receptor contribution to inflammation-induced calcific aortic valve disease

血清素受体对炎症引起的钙化主动脉瓣疾病的贡献

基本信息

批准号：
10365996
负责人：
Linda L. Demer
金额：
$ 39万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10365996
关键词：
3-Dimensional Affect Agonist Aortic Valve Stenosis Apolipoprotein E Atomic Force Microscopy Attenuated BMP2 gene Biomechanics C57BL/6 Mouse Calcium Channel Cardiovascular system Cell membrane Cells Cholesterol Cicatrix Clinical Research Computers Disease Elderly Event Fibrosis Fluorescence Microscopy Genetic Genetically Engineered Mouse Heart Valves Hydrogels Hyperlipidemia Image Implant Individual Inflammation Inflammatory Lasers Lead Lesion Light Link Measures Mechanics Mediating Medicine Modulus Morbidity - disease rate Mus Nodule Osteogenesis Pathogenesis Pathway interactions Patients Peripheral Pharmacological Treatment Pharmacology Play Process Public Health Reporting Role Serotonergic System Serotonin Serotonin Agents Serotonin Receptor 5-HT2B Serum Signal Pathway Signal Transduction Structure TNF gene Techniques Technology Testing Time Up-Regulation Wild Type Mouse antagonist aortic valve aortic valve disorder base calcification cell type cytokine experimental study implantation in vivo inflammatory milieu inhibitor innovation insight interstitial cell knock-down mRNA Expression mineralization mortality mouse model mutant osteoblast differentiation prevent receptor serotonin receptor subcutaneous

项目摘要

PROJECT SUMMARY/ABSTRACT No pharmacological approach has been found to prevent/treat calcific aortic valve disease (CAVD), whose pathophysiological changes include calcification and fibrosis, causing aortic stenosis, often in combination with regurgitation. Evidence shows that pro-inflammatory cytokines are potent stimulators of cardiovascular calcification, while the serotonergic system is a potent stimulator of fibrosis. In particular, serotonin receptor 2B (SR-2B) activation is known to cause structural and mechanical changes in aortic valves, such as fibrosis and thickening, in some cases, dense nodules, though not calcification. Clinical studies also show that serotonin (5- HT) levels are almost twice as high in patients with aortic stenosis, and are significantly associated with progression of aortic stenosis. These findings suggest that SR-2B activation also contributes to the pathogenesis of inflammation-induced CAVD. Interestingly, as confirmed in our preliminary studies, the predominant receptor subtype expressed in murine aortic valve interstitial cells, at baseline, is SR-2A, rather than SR-2B. However, in our additional preliminary studies, we found that it was SR-2B that was dramatically upregulated (> 30-fold) by TNF-a. This induction required BMP-2 signaling and may account for our findings that, although 5-HT augmented TNF-a-induced calcification, it had no effect alone.. We also found that the TNF-a/5-HT-induced calcification occurred via induction of Orai1, a plasma membrane calcium channel, and this calcification was attenuated by specific inhibitors or knockdown of only SR-2B. Additional preliminary studies show that circulating peripheral 5-HT levels were higher in hyperlipidemic (Apoe-/-) compared with wild type mice, and SR-2B expression in the valve cusps was adjacent to cholesterol clefts and calcified lesions in Apoe-/- but not in wild type mice. Based on the collective evidence, we hypothesize that 5-HT in the hyperlipidemic milieu plays a key role in CAVD. We posit that hyperlipidemia increases circulating levels of both 5-HT and inflammatory cytokines, the latter of which induce SR-2B and osteogenesis in valve cusps, and, together, these events lead to CAVD. In Aim 1, we will determine receptor subtype-specific effects of 5-HT on matrix mechanics under non-inflammatory (SR-2A dominant) as well as on calcification under inflammatory (SR-2B dominant) conditions and on the signaling pathways mediating TNF-a induction of SR-2B and of downstream osteoblastic differentiation. In Aim 2, we will determine whether 5-HT signaling via SR-2B is critical for inflammation-induced CAVD using 1) a 5-HT-deficient, inflammatory mouse model (Tph1-/-Ldlr-/- Apob100/100), and 2) receptor subtype-specific agonists and antagonists. We will apply cutting edge technology, including laser light sheet fluorescence microscopy; serial in vivo fused 18F-µPET-µCT imaging; atomic force microscopy; 3-D hydrogel cultures; and implantation of receptor subtype knockdown cells. The proposed experiments will elucidate how 5-HT receptor subtype-specific signaling changes the structure of valve cusps and whether targeting SR-2B opens the path for effective pharmacological-based treatment of CAVD.

项目概要/摘要尚未发现预防/治疗钙化性主动脉瓣疾病 (CAVD) 的药物方法，其病理生理变化包括钙化和纤维化，导致主动脉瓣狭窄，通常与反流。有证据表明促炎细胞因子是心血管的有效刺激剂钙化，而血清素系统是纤维化的有效刺激剂。特别是，血清素受体 2B (SR-2B) 激活已知会引起主动脉瓣的结构和机械变化，例如纤维化和增厚，在某些情况下，致密结节，但不是钙化。临床研究还表明，血清素（5- HT）水平在主动脉瓣狭窄患者中几乎是其两倍，并且与主动脉瓣狭窄患者显着相关。主动脉瓣狭窄的进展。这些发现表明 SR-2B 激活也有助于炎症诱导的 CAVD 的发病机制。有趣的是，正如我们的初步研究所证实的，基线时，在小鼠主动脉瓣间质细胞中表达的主要受体亚型是 SR-2A，而不是比SR-2B。然而，在我们额外的初步研究中，我们发现 SR-2B 显着地 TNF-a 上调（> 30 倍）。这种诱导需要 BMP-2 信号传导，并且可能解释我们的发现表明，虽然 5-HT 增强了 TNF-α 诱导的钙化，但单独使用并没有效果。我们还发现 TNF-a/5-HT 诱导的钙化是通过诱导 Orai1（质膜钙通道）和这种钙化可通过特定抑制剂或仅敲除 SR-2B 来减弱。附加初步研究表明，与野生动物相比，高脂血症 (Apoe-/-) 患者的循环外周 5-HT 水平较高型小鼠中，SR-2B 在瓣膜尖部的表达与胆固醇裂隙和钙化病变相邻。 Apoe-/- 但不在野生型小鼠中。根据集体证据，我们假设 5-HT 高脂血症环境在 CAVD 中起着关键作用。我们认为高脂血症会增加循环水平 5-HT 和炎症细胞因子，后者诱导 SR-2B 和瓣尖成骨，并且，这些事件共同导致 CAVD。在目标 1 中，我们将确定 5-HT 的受体亚型特异性效应非炎症（SR-2A 主导）下的基质力学以及炎症下的钙化（SR-2B 占主导地位）条件以及介导 TNF-a 诱导 SR-2B 和的信号通路下游成骨细胞分化。在目标 2 中，我们将确定通过 SR-2B 的 5-HT 信号传输是否有效对于炎症诱导的 CAVD 至关重要，使用 1) 5-HT 缺陷型炎症小鼠模型 (Tph1-/-Ldlr-/- Apob100/100) 和 2) 受体亚型特异性激动剂和拮抗剂。我们将应用尖端技术，包括激光光片荧光显微镜；系列体内融合 18F-μPET-μCT 成像；原子力显微镜检查； 3-D 水凝胶培养物；以及受体亚型敲低细胞的植入。拟议的实验将阐明 5-HT 受体亚型特异性信号传导如何改变瓣膜尖点的结构以及靶向 SR-2B 是否为 CAVD 的有效药物治疗开辟了道路。