Modulation of Lymphatic System Function by LTB4

项目摘要 淋巴水肿是一种主要影响乳腺癌患者术后的毁灭性疾病， 导致四肢肿胀、组织纤维化和全身不适。目前没有 可用于治疗水肿的药物治疗。然而，花生四烯酸的代谢物LTB 4具有 与水肿的发展有关，并被确定为可能的药物靶点。的目标 这项研究旨在确定LTB 4是否驱动淋巴集合管衰竭，并确定LTB 4的直接机制。 LTB 4对淋巴集合管的作用。假设LTB 4抑制淋巴集合管， 损伤后发生高浓度的收缩，导致淋巴功能不全和极端 水肿中发现肿胀。我们预测LTB 4的这种功能效应通过两种机制发生; LTB 4直接作用于淋巴集合管以抑制泵送，并且LTB 4驱动巨噬细胞募集 损伤部位，通过分泌VEGFC和iNOS进一步扩大疾病进展， 淋巴功能的影响因素。 为了测试LTB 4浓度如何影响淋巴集合管功能，我们将首先使用分离的 血管设置以测试不同浓度的LTB 4对淋巴管张力和收缩性的直接影响。 我们还将确定LTB 4对淋巴管收缩性的影响是否由其受体BLT 1介导 和/或BLT 2。接下来，称为bestatin的LTB 4拮抗剂将与单血管结扎结合使用。 小鼠水肿模型，以研究LTB 4在疾病进展期间如何影响集合血管功能。在 单血管结扎模型、主要集合血管和周围初始血管将被 烧灼，而一个收集容器将保持完整。通过使用近红外成像技术来测量收缩 手术后，在这个收集血管的功能，LTB 4拮抗作用对收缩功能的影响， 可以确定疾病进展。这个手术模型将在一个遗传巨噬细胞耗竭测试 小鼠模型，以检查是否存在巨噬细胞介导的LTB 4对收集血管泵功能的影响 在水肿的发展过程中。巨噬细胞的VEGFC分泌和iNOS表达将在 LTB 4拮抗作用的背景，以确定巨噬细胞调节淋巴细胞的机制， 功能这项研究的结果将有助于阐明LTB 4在水肿发展中的作用， 描述其对淋巴系统功能的直接影响，并确定LTB 4 导致淋巴集合管泵故障。这些结果将是朝着更好的 了解水肿进展，并将告知使用药物治疗， 以LTB 4及其代谢为靶点的水肿。研究培训将在格鲁吉亚研究所举行， 技术，一个世界级的研究机构，拥有充足的设施和资源，以帮助指导一个年轻的研究人员 走向学术生涯

Project Abstract Lymphedema is a devastating disease that predominantly affects breast cancer patients post-surgery, leading to swelling at the extremities, tissue fibrosis, and general discomfort. There are currently no pharmacological treatments available for lymphedema. However, LTB4, a metabolite of arachidonic acid, has been implicated in the development of lymphedema and identified as a possible drug target. The objective of this study is to determine if LTB4 drives lymphatic collecting vessel failure and identify the direct mechanism of action for LTB4 on lymphatic collecting vessels. The hypothesis is that LTB4 inhibits lymphatic collecting vessel contraction at high concentrations occurring post-injury, leading to lymphatic insufficiency and the extreme swelling found in lymphedema. We predict that this functional effect of LTB4 occurs through two mechanisms; LTB4 directly acts on lymphatic collecting vessels to inhibit pumping, and LTB4 drives macrophage recruitment to the site of injury, further amplifying disease progression through secretion of VEGFC and iNOS, known effectors of lymphatic function. To test how LTB4 concentration affects lymphatic collecting vessel function, we will first use an isolated vessel setup to test the direct effect of varying concentrations of LTB4 on lymphatic vessel tone and contractility. We will also determine if the effect of LTB4 on lymphatic vessel contractility is mediated by its receptors, BLT1 and/or BLT2. Next, an LTB4 antagonist called bestatin will be used in conjunction with a single vessel ligation lymphedema model in mice to study how LTB4 affects collecting vessel function during disease progression. In the single vessel ligation model, the dominant collecting vessel and the surrounding initial lymphatics will be cauterized while one collecting vessel will be left intact. By using NIR imaging techniques to measure contractile function in this collecting vessel after surgery, the effect of LTB4 antagonism on contractile function during disease progression can be determined. This surgical model will be tested in a genetic macrophage depletion mouse model to examine if there is a macrophage-mediated effect of LTB4 on collecting vessel pump function during lymphedema development. VEGFC secretion and iNOS expression by macrophages will be quantified in the context of LTB4 antagonism to determine the mechanism by which macrophages modulate lymphatic function. The results of this study will help elucidate the role of LTB4 in the development of lymphedema, characterize its direct effect on lymphatic system function, and identify multiple mechanisms by which LTB4 drives lymphatic collecting vessel pump failure. These results will be an important step towards a better understanding of lymphedema progression and will inform the use of pharmacotherapeutic treatments for lymphedema targeting LTB4 and its metabolism. The research training will take place at the Georgia Institute of Technology, a world-class research institute with ample facilities and resources to help guide a young researcher towards a career in academia.