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.

项目摘要 /摘要微血管功能障碍是从阿尔茨海默氏病到癌症的广泛毁灭性疾病的基础。然而，在血管相关病理中，维持血管维护的基础机制仍在出现，加剧了基于血液的诊断和生物工程疗法的进步。我们最近确定了血小板衍生的生长因子受体-β（PDGFRβ）的截短的替代剪接变体该编码固体PDGFRβ同工型（SPDGFRβ）可能具有将来的诊断潜力和治疗靶标。受体酪氨酸激酶（RTK），例如PDGFRβ，通常具有固体对应物通过替代剪接生成以充当“诱饵”受体，以负调节配体诱导的信号传导全长受体。全长PDGFRβ用周细胞（PC）表达，以介导其募集到产生同源配体血小板衍生的生长因子BB的微血管内皮细胞（ECS）（PDGF-- BB） - PC促进血管稳定性和调谐渗透性的位置。但是，微血管PC密度和容器渗透率在组织和专门的血管床之间有所不同，血管功能障碍通常与 PC丢失和未调节的PDGFRβ-PDGF-BB信号传导。 PDGFRβ介导的PC募集对于船舶完整性，尽管尚不清楚它的确切机制。最近的研究报告了很大的通过蛋白水解裂解产生的SPDGFRβ在脑病理情景中。但是，我们的数据表明小型SPDGFRβ是通过在广泛的正常健康组织中通过替代剪接而产生的，尽管它也是可能参与疾病状态。我们最近阐明了SPDGFRB的完整mRNA序列，使得有针对性操纵和分析方法。除了在各种时机之间进行广泛和差异表达外，我们的初步发现表明与全长PDGFRB（FPDGFRB）表达小鼠大脑中的细胞和在脑实质中存在免疫可免疫，非血管相关的SPDGFRβ蛋白信号。这些研究结果与相关RTK中配体隔离的确定机制一起考虑，请告知我们假设PDGF-BB生物利用度受替代剪接的SPDGFRβ调节以介导PC-vessel 募集和调谐容器的渗透性。因此，使用体外和体内模型，我们 SPDGFRβ潜力的建议研究和调节（i）PDGF-BB生物利用度，（ii）激活全长PDGFRβ（FPDGFRβ），（III）PC动力学和（IV）发展血管形态和渗透性。我们将研究SPDGFRβ细胞特异性和在各种时机中的时空分布，以确定其功能作用的程度。此外，我们将评估SPDGFRβ作为生物标志物的潜力和处理在涉及PC丢失的血管相关病理中。这项工作将提高我们对机制的理解基本的船舶维护和完整性，并为后续协作研究奠定了基础开发SPDGFRβ作为心血管疾病中的潜在诊断工具和治疗靶标。