VEGFR Signaling Controls Lymphatic Junctions

VEGFR 信号传导控制淋巴连接

• 批准号: 10502986
• 负责人: Joshua Paul SCALLAN
• 金额: $ 66.09万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10502986
• 关键词: Address; Adherens Junction; Affect; Beds; Binding; Biological Process; Birth; Blood Vessels; Breast Cancer Patient; Cell Culture Techniques; Cells; Cellulitis; Data; Development; Disease; Ear; Embryo; Excision; FLT4 gene; Fibrosis; Functional disorder; Gene Mutation; Genes; Hereditary lymphedema; Hindlimb; Image; Impairment; Infection; Infectious Skin Diseases; Inherited; Intercellular Fluid; Intercellular Junctions; KDR gene; Knock-out; Knockout Mice; Knowledge; Laboratories; Lead; Leg; Life; Ligands; Limb structure; Link; Liquid substance; Lymph; Lymphangiogenesis; Lymphatic; Lymphatic Capillaries; Lymphatic function; Lymphedema; Maintenance; Malignant Neoplasms; Messenger RNA; Missense Mutation; Modeling; Molecular; Mus; Mutation; Near-infrared optical imaging; Outcome; Pathogenesis; Patients; Persons; Pharmacological Treatment; Pharmacology; Pharmacotherapy; Physiological; Predisposition; Protein Isoforms; Proteins; Receptor Protein-Tyrosine Kinases; Respiratory Diaphragm; Role; Sepsis; Signal Pathway; Signal Transduction; Skin; Swelling; Syndrome; Tail; Testing; Tissues; Tracer; VEGFC gene; Vascular Endothelial Growth Factor Receptor-3; Vascular Endothelium; Work; absorption; cadherin 5; clinically relevant; comorbidity; drug development; effective therapy; in vitro Model; in vivo; insight; knock-down; lymph flow; lymph nodes; lymphatic dysfunction; lymphatic malformations; lymphatic vasculature; lymphatic vessel; lymphoscintigraphy; methicillin resistant Staphylococcus aureus; mouse model; negative affect; new growth; notch protein; novel; overexpression; postnatal; receptor; shear stress; virtual

Congenital lymphedema is caused by inherited gene mutations that impair the functioning of the lymphatic vasculature and lead to swelling of the limbs, disfigurement, cellulitis, and increased susceptibility to MRSA infections of the skin and sepsis. Congenital lymphedema is also a comorbidity of lymphatic malformations and other common syndromes (e.g. Noonan). The most common gene mutation that causes congenital lymphedema is a heterozygous inactivating mutation in the VEGFR3 gene that causes Milroy’s disease. While VEGFR3 has been widely studied as the main receptor that induces lymphangiogenesis, virtually nothing is known about how VEGFR3 regulates physiological functions of the lymphatic vasculature. Thus, the pathogenesis of Milroy’s disease remains unknown, prohibiting the development of drug therapies. Patients with congenital mutations in VEGFR3 have lower leg lymphedema and upon lymphoscintigraphy imaging it is revealed that their lymphatic vessels are unable to absorb any tracer from the interstitium. Here, we have developed a mouse model in which the VEGFR3 gene can be deleted specifically from the lymphatic vasculature to understand its physiological functions. Our preliminary data show that loss of VEGFR3 negatively affects the ability of lymphatic capillaries to remodel their continuous cell-cell junctions, reminiscent of zippers, into discontinuous wide-open junctions called buttons. Junctional remodeling in the lymphatic capillaries is a relatively new biological process that is poorly understood but relies on the adherens junction protein, VE-cadherin, in which our laboratory has expertise. Importantly, the button junctions are thought to enable fluid absorption from the interstitium. Our preliminary data identify VEGFR3 as a novel regulator of lymphatic capillary junction remodeling to form button junctions. We will combine this mouse model with cell culture and physiological approaches to investigate the role of VEGFR3 in the lymphatic vasculature in the following specific aims. In Aim 1, we will assess the ability of lymphatic capillaries to remodel their junctions in the absence of VEGFR3 at various timepoints after birth. We will also investigate whether VEGFR3 is required not only for button junction formation, but also for the lifelong maintenance of these special junctions. Lymph flow will be assessed in vivo to determine how the loss of button junctions affects physiological interstitial fluid absorption. In Aim 2, we will investigate the downstream cell signals that regulate button junction formation and identify the signaling pathways involved using a variety of approaches. The completion of these aims will identify a new signaling pathway by which VEGFR3 controls lymphatic junction remodeling to enable interstitial fluid absorption by the lymphatic capillaries. This work will significantly impact patients with congenital lymphedema by providing mechanistic insight into the pathogenesis of the disease, opening the door to developing pharmacological treatments.

先天性淋巴水肿是由遗传性基因突变导致的，这些基因突变损害了淋巴的功能。 血管形成并导致四肢肿胀、毁容、蜂窝组织炎和增加对MRSA的易感性 皮肤感染和败血症。先天性淋巴水肿也是淋巴畸形和 其他常见综合征(如Noonan)。导致先天性心脏病的最常见的基因突变 淋巴水肿是一种VEGFR3基因的杂合失活突变，导致米尔罗伊氏病。而当 血管内皮生长因子受体3已被广泛研究为诱导淋巴管生成的主要受体，几乎没有一种是 了解VEGFR3如何调节淋巴管系统的生理功能。因此， 米尔罗伊氏病的发病机制尚不清楚，这阻碍了药物治疗的发展。病人 患有先天性VEGFR3突变的患者有小腿淋巴水肿，淋巴核素扫描显示 他们的淋巴管无法吸收间质中的任何示踪剂。在这里，我们有 建立了一种小鼠模型，在该模型中，VEGFR3基因可以从淋巴管中特异性地删除 血管系统，以了解其生理功能。我们的初步数据显示VEGFR3的缺失 对毛细淋巴管重建其连续的细胞-细胞连接的能力产生负面影响，这让人想起 拉链，变成不连续的完全打开的连接处，称为纽扣。淋巴管的连接重塑 毛细血管是一个相对较新的生物学过程，人们对它知之甚少，但它依赖于粘着连接。 蛋白质，VE-钙粘附素，我们的实验室在这方面有专长。重要的是，按钮结被认为是 使流体能够从间质中吸收。我们的初步数据确定VEGFR3是一种新的调节因子 毛细淋巴管连接重构，形成纽扣连接。我们将把这个小鼠模型与细胞相结合 培养和生理学方法研究血管内皮生长因子受体3在小鼠淋巴管中的作用 遵循特定的目标。在目标1中，我们将评估淋巴管重建其连接的能力。 VEGFR3在出生后不同时间点的缺失。我们还将调查是否需要VEGFR3 不仅用于纽扣结的形成，还用于这些特殊结点的终身维护。淋巴 血流将在体内进行评估，以确定按钮连接的丢失如何影响生理间质液体 吸收。在目标2中，我们将研究调节按钮连接形成和 使用各种方法确定所涉及的信号通路。这些目标的实现将 确定VEGFR3控制淋巴连接重塑的新信号通路以使间质 淋巴管对液体的吸收。这项工作将对先天性心脏病患者产生重大影响。 淋巴水肿通过提供对疾病发病机制的机械洞察，打开了 开发药物治疗方法。