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.

项目摘要/摘要尚未发现药物方法可以预防/治疗钙化主动脉瓣疾病（CAVD）病理生理的变化包括钙化和纤维化，导致主动脉狭窄，通常与反流。有证据表明，促炎性细胞因子是心血管的潜在刺激剂钙化，而血清素能系统是纤维化的潜在刺激剂。特别是5-羟色胺受体2b （SR-2B）已知激活会导致主动脉瓣的结构和机械变化，例如纤维化和在某些情况下，增厚，尽管不是钙化，但仍致密结节。临床研究还表明5-羟色胺（5- HT）水平几乎是正向狭窄的患者的两倍，并且与主动脉狭窄的进展。这些发现表明SR-2B激活也有助于炎症引起的CAVD的发病机理。有趣的是，正如我们的初步研究所证实的那样基线时在鼠主动脉瓣间质瓣中表达的主要受体亚型为SR-2A，而是比SR-2B。但是，在我们的其他初步研究中，我们发现是SR-2B急剧 TNF-A更新（> 30倍）。这种归纳需要BMP-2信号传导，可能会说明我们的发现那是，尽管5-HT增强了TNF-A诱导的钙化，但它并没有单独效果。我们也发现 TNF-A/5-HT诱导的钙化发生通过诱导ORAI1，质膜钙通道和该计算被特定抑制剂或仅敲低SR-2B减弱。其他初步研究表明，与野生相比类型小鼠，瓣膜中的SR-2B表达与胆固醇裂缝相邻，并计算出病变 apoe - / - 但不在野生型小鼠中。根据集体证据，我们假设在高脂血症环境在CAVD中起关键作用。我们肯定高脂血症会增加循环水平 5-HT和炎性细胞因子，后者诱导瓣膜中的SR-2B和成骨，以及这些事件一起导致了CAVD。在AIM 1中，我们将确定5-HT的受体亚型特异性效应在非炎症（SR-2A显性）以及炎症下的钙化下，基质力学（SR-2B主导）条件以及介导TNF-A诱导SR-2B的信号通路下游成骨细胞分化。在AIM 2中，我们将确定通过SR-2B的5-HT信号传导是否为使用1）5-HT缺乏症，炎症小鼠模型（TPH1 - / - LDLR - / - 至关重要 APOB100/100）和2）受体亚型特异性激动剂和拮抗剂。我们将采用尖端技术，包括激光板荧光显微镜；串行体内融合18F µPET-µCT成像；原子力显微镜； 3-D水凝胶培养物；和受体亚型敲低细胞的植入。提议实验将阐明5-HT接收器亚型特异性信号如何改变瓣膜的结构以及靶向SR-2B是否为CAVD的有效基于药物治疗的路径开辟了道路。