A Tissue-Specific Soluble Platelet-Derived Growth Factor Receptor-beta Isoform Retains Functional Capacity

组织特异性可溶性血小板衍生生长因子受体-β亚型保留功能能力

基本信息

批准号：
10668031
负责人：
John Christopher Chappell
金额：
$ 24万
依托单位：
VIRGINIA POLYTECHNIC INST AND ST UNIV
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10668031
关键词：
Activities of Daily Living Affinity Chromatography Alternative Splicing Alzheimer&apos s Disease Binding Biological Assay Biological Availability Biological Markers Biological Process Biomedical Engineering Blood Blood Vessels Blood capillaries Brain Capillary Endothelial Cell Cardiovascular Diseases Cells Cerebrum Custom Data Diagnostic Disease Docking Drug or chemical Tissue Distribution Endothelial Cells Extracellular Matrix Flow Cytometry Fluorescence Functional disorder Future Genetic Engineering Goals Growth Factor Growth Factor Receptors Hand Heparin Hybrids Immunohistochemistry In Vitro Investigation Investments Length Ligands Maintenance Malignant Neoplasms Mediating Messenger RNA Microvascular Dysfunction Modeling Morphology Mus Normal Range PDGFRL gene Pathology Pericytes Permeability Physiological Platelet-Derived Growth Factor beta Receptor Proliferating Protein Isoforms Proteins Quantitative Reverse Transcriptase PCR Receptor Protein-Tyrosine Kinases Recombinants Regulation Reporter Reporting Research Design Role Signal Induction Signal Transduction Signaling Protein Spatial Distribution Specificity Testing Therapeutic Tissues Transcript Variant Vascular Endothelial Cell Work blood-based biomarker brain parenchyma cell type confocal imaging density diagnostic tool differential expression heparin proteoglycan in vivo Model insight knock-down migration platelet-derived growth factor BB receptor recruit spatiotemporal therapeutic target vascular bed

项目摘要

PROJECT SUMMARY / ABSTRACT Microvascular dysfunction underlies a wide range of devastating diseases, from Alzheimer’s Disease to cancer. However, mechanisms underlying vessel maintenance that become dysregulated in vascular-related pathologies are still emerging, fueling the advancement of blood-based diagnostics and bioengineered therapeutics. We recently identified a truncated, alternative splice variant of Platelet-Derived Growth Factor Receptor-β (PDGFRβ) that encodes a soluble PDGFRβ isoform (sPDGFRβ), which may harbor potential as a future diagnostic and therapeutic target. Receptor tyrosine kinases (RTKs), like PDGFRβ, often have soluble counterparts that are generated via alternative splicing to function as “decoy” receptors to negatively regulate ligand-induced signaling of the full-length receptor. Full-length PDGFRβ is expressed by pericytes (PCs) to mediate their recruitment to microvascular endothelial cells (ECs) producing the cognate ligand Platelet-Derived Growth Factor BB (PDGF- BB) – where PCs promote vessel stability and tune permeability. However, microvascular PC density and vessel permeability vary between tissues and specialized vascular beds, with vessel dysfunction often associated with PC loss and misregulated PDGFRβ--PDGF-BB signaling. Thus PDGFRβ-mediated PC recruitment is vital to vessel integrity, although the exact mechanisms that govern it remain unclear. Recent studies report a large sPDGFRβ produced via proteolytic cleavage in cerebral pathology scenarios. However, our data indicate that a small sPDGFRβ is generated via alternative splicing in a broad range of normal, healthy tissues, though it is also likely involved in disease states. We recently elucidated the full mRNA sequence of sPdgfrb, enabling targeted manipulation and analysis approaches. In addition to broad and differential expression across various tissues, our preliminary findings indicate overlap with full-length Pdgfrb (fPdgfrb)-expressing cells in mouse brain, and presence of immunolabled, non-vessel associated sPDGFRβ protein signal in the brain parenchyma. These findings, considered alongside established mechanisms of ligand sequestration in related RTKs, inform our hypothesis that PDGF-BB bioavailability is regulated by alternatively spliced sPDGFRβ to mediate PC-vessel recruitment and tune vessel permeability. Therefore, using complementary in vitro and in vivo models, we propose investigation of sPDGFRβ potential to bind and regulate (i) PDGF-BB bioavailability, (ii) activation of full-length PDGFRβ (fPDGFRβ), (iii) PC dynamics, and (iv) developing vessel morphology and permeability. We will investigate sPDGFRβ cell-specificity, and spatio-temporal distribution in various tissues to determine the extent of its functional role. In addition, we will assess the potential of sPDGFRβ as a biomarker and treatment in vascular-related pathologies involving PC loss. This work will advance our understanding of mechanisms underlying vessel maintenance and integrity, and lay the groundwork for follow-on collaborative studies aiming to develop sPDGFRβ as a potential diagnostic tool and therapeutic target in cardiovascular diseases.

项目概要/摘要微血管功能障碍是多种破坏性疾病的根源，从阿尔茨海默病到癌症。然而，血管维护的潜在机制在血管相关病理中变得失调仍在不断涌现，推动了基于血液的诊断和生物工程治疗的进步。最近发现了血小板衍生生长因子受体-β（PDGFRβ）的截短的选择性剪接变体编码可溶性 PDGFRβ 亚型 (sPDGFRβ)，可能具有作为未来诊断和治疗的潜力受体酪氨酸激酶 (RTK)，如 PDGFRβ，通常具有可溶性键。通过选择性剪接产生，作为“诱饵”受体，负向调节配体诱导的信号传导全长 PDGFRβ 由周细胞 (PC) 表达，以介导其招募微血管内皮细胞 (EC) 产生同源配体血小板衍生生长因子 BB (PDGF- BB) – PC 促进血管稳定性并调节渗透性，但微血管 PC 密度和血管。组织和专门血管床之间的渗透性不同，血管功能障碍通常与 PC 丢失和失调的 PDGFRβ-PDGF-BB 信号传导因此 PDGFRβ 介导的 PC 募集至关重要。血管完整性，尽管控制它的确切机制仍不清楚。然而，我们的数据表明，sPDGFRβ 在脑病理情况下通过蛋白水解裂解产生。小 sPDGFRβ 是通过多种正常健康组织中的选择性剪接产生的，尽管它也我们最近阐明了 sPdgfrb 的完整 mRNA 序列，从而实现了靶向治疗。除了跨不同组织的广泛和差异表达之外，我们的初步研究结果表明与小鼠大脑中表达全长 Pdgfrb (fPdgfrb) 的细胞重叠，并且脑实质中存在免疫标记的、非血管相关的 sPDGFRβ 蛋白信号。研究结果与相关 RTK 中已建立的配体隔离机制一起考虑，为我们提供了信息假设 PDGF-BB 生物利用度是通过选择性剪接的 sPDGFRβ 介导 PC 血管来调节的因此，我们使用互补的体外和体内模型。研究 sPDGFRβ 结合和调节 (i) PDGF-BB 生物利用度，(ii) 激活的潜力全长 PDGFRβ (fPDGFRβ)，(iii) PC 动力学，以及 (iv) 发育血管形态和渗透性。将研究 sPDGFRβ 细胞特异性和各种组织中的时空分布，以确定此外，我们将评估 sPDGFRβ 作为生物标志物和治疗的潜力。这项工作将促进我们对涉及 PC 丢失的血管相关病理的理解。底层船舶维护和完整性，并为后续合作研究奠定基础开发 sPDGFRβ 作为心血管疾病的潜在诊断工具和治疗靶点。