The Role of Tie1 in Gut and Mesenteric Lymphatic Function

Tie1 在肠道和肠系膜淋巴功能中的作用

• 批准号: 10614926
• 负责人: H Scott Baldwin
• 金额: $ 42.02万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10614926
• 关键词: Adipocytes; Adult; Area; Ascites; Birth; Body Composition; Body Weight; CRISPR/Cas technology; Cells; Cholesterol; Data; Development; Dyslipidemias; Embryo; Endothelium; Exposure to; Fat-Soluble Vitamin; Fluid Balance; Functional disorder; Gene Expression Profile; Genes; Genetic Transcription; Glucose; Goals; High Fat Diet; Hormones; Immunologic Surveillance; Individual; Inflammation; Inflammatory; Insulin; Intestines; Investigation; Laboratories; Leptin; Ligands; Lipids; Lymphatic; Lymphatic Endothelial Cells; Lymphatic System; Lymphatic function; Lymphedema; Maintenance; Malnutrition; Measures; Mediating; Metabolic; Metabolic Diseases; Missense Mutation; Morphology; Mus; Nutrient; Obesity; Pathologic Processes; Pathology; Phenotype; Play; Population; Prevention; Process; Protein-Losing Enteropathies; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Role; Signal Pathway; Signal Transduction; Structure; TIE gene; Tamoxifen; Therapeutic Intervention; Thymidine Kinase; Tissues; Vascular Endothelial Cell; Weight Gain; absorption; adiponectin; attenuation; diet-induced obesity; dietary; gastrointestinal; gastrointestinal system; in utero; in vivo; insight; juvenile animal; lacteal; lipid transport; long chain fatty acid; lymph flow; lymphatic development; lymphatic malformations; lymphatic valve; lymphatic vasculature; mature animal; mesenteric lymphatics; mouse model; mutant; new therapeutic target; novel; nutrient absorption; postnatal; postnatal period; prenatal; receptor; single-cell RNA sequencing; uptake

PROJECT SUMMARY The lymphatic system is critical for tissue fluid homeostasis, lipid absorption, and immune surveillance and is no longer considered a “passive bystander” in pathological processes. The digestive lymphatic system, includ-ing intestinal and mesenteric lymphatics, plays a critical role in several pathological processes including obe-sity, metabolic disease, and dyslipidemia in addition to lymphedema and inflammation. 3,4 While prenatal lym-phatic development has been an area of intensive investigation, insights into factors involved in post-natal reg-ulation of lymphatic maturation, remodeling, and maintenance of lymphatic structure and function is limited. Our laboratory has recently shown that the receptor tyrosine kinase TIE1 is required for lymphatic remodeling and normal lymphatic function in utero, and that deletion of Tie1 specifically from the developing lymphatic vas-culature prior to birth results in abnormal LV formation. We present new preliminary data that deletion of Tie1 in the early post-natal period results in malnutrition with poor weight gain, abnormal LV maturation, and asci-tes. In contrast, we show that Tie1 deletion in the adult animal results in severe LV dysfunction and profound diet-induced obesity (DIO) when challenged with a high fat diet (HFD). We hypothesize that TIE1 cell auton-omous and non-cell autonomous signaling plays a unique role in orchestrating early post-natal LV and lacteal maturation and function, and that TIE1 signaling is essential for maintenance of LV and lacteal structure and function in the mature animal. Therefore, we propose to: 1) Delineate the specific role of TIE1 signaling in early post-natal lacteal and LV maturation, and nutrient absorption, in vivo. Tie1fl/fl mice and an inducible LEC Cre line, Prox1CreERT, will be used to produce LEC-specific, temporal deletion of Tie1 (Tie1lecKO) in post-natal lymphatics. Quantitative and functional analyses will be used to characterize the unique phenotypes that result from TIE1 attenuation in intestinal lacteals and mesenteric LVs. 2) Determine the role of TIE1 in maintenance of lymphatic function in the adult and characterize its role in mediating DIO. Tie1lecKO and control (Tie1fl/fl) adult mice will be place on a 60% HFD or normal chow for 6 weeks following exposure to Tamoxifen. LV structure and function will be measured as well as alterations in body weight and composition, levels of circulating hormones insulin, leptin and adiponectin, sensitivity to glucose and insulin, and adipocyte morphology and inflammatory status. 3) Define the mechanisms of TIE1-mediated signaling required for LV and lacteal remodeling and maintenance, in vivo. Utilizing CRISPR/Cas9, we have devel-oped mice with missense mutations in critical intracellular domains of Tie1. Unique domain-specific effects on LV and lacteal structure and function will be characterized in the early post-natal and adult animals during the dynamic reorganization and maintenance processes, respectively. scRNA-seq and sc-UniFrac analysis will be employed to define TIE1-dependent signaling required for cell autonomous and non-autonomous LEC subtype transcriptional signatures regulating maturation and maintenance of the GI lymphatic system after birth.

项目摘要 淋巴系统对于组织液稳态，脂质缓解和免疫监测至关重要，是 在病理过程中，不再被认为是“被动旁观者”。除淋巴水肿和炎症外，包括肠道和肠系膜淋巴管在内的消化性淋巴系统，包括肠道和肠系膜淋巴管，在包括OBE-性，代谢性疾病和血脂异常（包括OBE）性过程中起着至关重要的作用。产前3,4 淋巴发育一直是一项大量投资的领域，对淋巴成熟，重塑以及淋巴结结构和功能维持的涉及因素的见解是有限的。 我们的实验室最近表明，受体酪氨酸激酶TIE1是淋巴重塑所必需的 和子宫中的正常淋巴功能，以及在出生前从发育中的淋巴管肠系膜中删除TIE1，导致LV形成异常。我们提出了删除TIE1的新初步数据 相反，我们表明成年动物中的TIE1缺失导致严重的LV功能障碍和深刻 饮食引起的肥胖症（DIO）在受到高脂肪饮食（HFD）挑战时。我们假设TIE1细胞自动和非电池自主信号在编排早期产后LV和 乳酸成熟和功能，该TIE1信号对于维持LV和乳酸是必不可少的 成熟动物的结构和功能。因此，我们建议：1）描述 tie1信号传导在体内产生后产后乳酸和LV成熟以及营养滥用。 tie1fl/fl 小鼠和诱导的LEC CRE系Prox1creert将用于产生LEC特异性的临时缺失 产后淋巴机中的TIE1（TIE1LECKO）。定量和功能分析将用于表征 肠乳酸和肠系膜LVS中的TIE1衰减引起的独特表型。 2）确定 TIE1在维持淋巴功能在成人中的作用，并表征其在介导中的作用 dio。 TIE1lecko和对照（TIE1FL/FL）成年小鼠将在60％的HFD或正常食物上放置6周 暴露于他莫昔芬。 LV结构和功能将被测量，以及体重的改变 组成，循环激素胰岛素，瘦素和脂联素的水平，对葡萄糖和胰岛素的敏感性， 以及脂肪细胞的形态和炎症状态。 3）定义TIE1介导的信号传导的机制 LV和乳酸重塑和维护所需的体内。利用CRISPR/CAS9，我们在TIE1的关键细胞内结构域中有脱层的小鼠。独特的域特异性影响 LV和乳酸结构和功能将在早期产后和成年动物中进行表征 动态重组和维护过程。 scrna-seq和 SC-非纤维分析将是 用于定义细胞自主和非自主LEC亚型所需的TIE依赖性信号传导 出生后，转录签名会恢复胃肠道淋巴系统的成熟和维持。