Defining the lymphatic basis of protein losing enteropathy after Fontan palliation or inflammatory gut disease

定义 Fontan 姑息治疗或炎症性肠道疾病后蛋白质丢失性肠病的淋巴基础

• 批准号: 10661777
• 负责人: Gwendalyn J Randolph
• 金额: $ 74.62万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-30 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10661777
• 关键词: Affect; Blood; Blood Vessels; Budesonide; Child; Circulation; Common Ventricle; Complication; Confusion; Crohn' s disease; Disease; Epithelial Cells; Epithelium; Etiology; Experimental Animal Model; Failure; Functional Imaging; Heart; Heart Ventricle; Human; Inflammatory; Intercellular Junctions; Intestines; Lamina Propria; Life; Link; Liquid substance; Literature; Lung; Lymph; Lymphatic; Lymphatic System; Mesentery; Modeling; Participant; Pathologic; Patients; Procedures; Protein-Losing Enteropathies; Proteins; Research; Role; Signal Transduction; Steroids; Testing; Tissues; Venous system; clinically significant; improved; intestinal barrier; intestinal epithelium; lymph flow; lymphatic circulation; lymphatic dysfunction; lymphatic valve; lymphatic vasculature; mortality; negative affect; novel strategies; palliation; pressure; stem

ABSTRACT Protein-losing enteropathy (PLE) is the term given to the pathological phenomenon of protein dumping from the systemic circulation into the intestinal lumen. Various degrees of PLE are observed in a variety of otherwise unrelated diseases. For instance, PLE is a complication of the life-saving Fontan palliation procedure performed on children born with only a single ventricle of the heart to create a vascular diversion to the lungs to promote improved oxygenation of blood. Fontan-associated PLE is linked with high mortality: 30-50% over 5- to 10-years. Yet, PLE remains understudied. The dominant causal mechanisms underlying PLE appear to relate to (1) loss of barrier integrity at the intestinal epithelium or (2) functional disturbance of the lymphatic vasculature. Intestinal epithelial cell erosion would expose proteinaceous tissue fluid to the intestinal lumen. Furthermore, poor epithelial intercellular junctions might allow for the contents of the lamina propria interstitium to leak into the intestinal lumen. With respect to lymphatics, failure of lymph to flow away from the intestine uni-directionally toward the heart and instead to flow backwards from the body trunk toward the intestine with sufficient force to break across the epithelium may be a major cause of PLE. The literature presents Fontan palliation-associated PLE as a problem driven by lymphatic backflow, whereas PLE in IBD (such as Crohn's disease) is presented as being of mixed etiology that involves breach of epithelial integrity with possible additional contributions stemming from lymphatic dysfunction. However, it is acknowledged in the literature that the full basis of PLE in any of these conditions is uncertain and that there are several reasons why the current explanations may be questioned. We will carry out focused research on PLE that includes studies involving human participants as well as studies in experimental animal models. Our hypotheses are, first, that the lymphatic vasculature is a primary player in PLE affecting Fontan patients and IBD patients, and second, that the lymphatic vasculature must receive “two hits” to drive sufficient backflow of lymph to cause outflow from the intestinal barrier. The first of these hits has already been considered (but not completely tested) in the context of Fontan palliation: increased pressure within the chain of lymphangions (vessel units between lymphatic valves). We propose this second hit is an inflammatory signal that negatively affects lymphatic valves. The two-hit model may resolve a confusing observation in Fontan patients with PLE wherein treatments with steroids like budesonide can be effective. A steroid seems unlikely to strongly alter pressure in the venous and lymphatic systems, but it is easy to envision how steroids may help by reducing adverse inflammatory signalling associated with valve failure. If this model is correct, a path to therapies not previously considered to treat PLE may become evident.

摘要

项目成果

Gut-associated lymphoid tissue attrition associates with response to anti-α4β7 therapy in ulcerative colitis.

肠道相关淋巴组织磨损与溃疡性结肠炎抗α4β7 治疗的反应相关。

• DOI: 10.1101/2023.01.19.524731
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Canales-Herrerias,Pablo;Uzzan,Mathieu;Seki,Akihiro;Czepielewski,RafaelS;Verstockt,Bram;Livanos,Alexandra;Raso,Fiona;Dunn,Alexandra;Dai,Daniel;Wang,Andrew;Al-Taie,Zainab;Martin,Jerome;Ko,HuaibinM;Tokuyama,Minami;Tankelevich,M
• 通讯作者: Tankelevich,M