Collaborative Research: Role of Endothelial Cell Activation in Hypoxia Tolerance of an Elite Diver, the Weddell Seal

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。第一部分：非技术描述：威德尔海豹是南极的标志性物种，也是一名出色的潜水员，可以游到2000英尺深，在水下停留长达45分钟。然而，对于任何哺乳动物来说，潜水时血液中的低氧浓度以及回到水面后的恢复都是需要克服的挑战，这使得它们的潜水能力成为几十年来一直令科学家着迷的独特能力。这项研究项目将评估韦德尔海豹保护该物种免受潜水后果的生理过程。这项工作将结合实验室实验，在这些实验中，血管内的细胞将暴露在低氧条件下，类似于将在南极洲潜水海豹中测量的那些细胞。研究人员将测试一个新想法，即在长时间潜水之前进行几次短期潜水，可以让海豹调整自己的状态。对潜水过程中释放到血液中的化合物进行测量，结合对调节它们的基因的实验，将提供帮助海豹耐受这些极端条件的生化途径的线索。该项目允许记录个人海豹潜水，并向寻求研究这些海豹的更广泛的科学界提供此类信息，教育研究生和本科生以及博士后研究人员，并为中学生制作一本科学推广漫画书，以说明该项目的科学活动、目标和成果。第二部分：技术描述：韦德尔海豹是一种冠军潜水员，对低血氧浓度(低氧血症)和血液供应不足(缺血)具有很高的自然耐受性。该物种特有的过程保护其组织免受暴露在此类生理条件下的其他哺乳动物组织中观察到的炎症和氧化应激的影响。该项目旨在利用分子、细胞和代谢工具，了解保护海豹免受炎症和氧化应激影响的过程的特征。在长时间潜水之前重复短时间潜水被认为是为了对组织进行预调节，并激活保护过程。这项工作的新方面是对内皮细胞的研究，内皮细胞感知氧气和血流的变化，在屏气和细胞功能之间提供联系。这种方法是实验室实验之一，结合了在南极洲麦克默多站附近的冰营地进行的两年野外工作。这项研究由三个主要目标构成：1)利用几种生理、生化和基因组工具，包括CRSPR/Cas9基因敲除和基因敲除方法，通过动脉内皮细胞暴露于氧气和流量的变化来确定与缺氧和缺血耐受有关的分子途径。2)海豹长距离潜水时血液代谢产物的代谢分析。3)短潜水过程中海豹生理的代谢和基因组测定假想为预适应耐受反应。在野外，海豹潜入一个孤立的冰洞后将采集血液样本，并记录其潜水表现。预计血液中将含有代谢物，这些代谢物可能与实验室实验中确定的分子途径有关。专家合作者将提供现场支持，包括冰营、海豹潜水洞和与海豹潜水相关的遥测。该项目建立在之前NSF资助的海豹基因组和细胞资源产生项目的基础上。本科生研究人员将从有吸引代表性不足的少数族裔和为少数族裔服务的机构项目中招聘。为了进一步增加极地扫盲培训和教育影响，实地小组将包括一个博客，在那里分享实地经验，并与一名艺术家一起为K-12学生和公共外游设计漫画书。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Part I: Non-technical description: The Weddell seal is an iconic Antarctic species and a superb diver, swimming down to 2,000 feet and staying underwater for up to 45 minutes. However, as for any mammal, the low oxygen concentrations in the blood during diving and the recovery once back at the surface are challenges that need to be overcome making their diving ability something unique that has fascinated scientists for decades. This research project will evaluate the underlying processes in Weddell seal’s physiology that protects this species from the consequences of diving. The work will combine laboratory experiments where cells that line the blood vessels will be exposed to conditions of low oxygen, similar to those that will be measured in diving seals in Antarctica. The investigarors will test a new idea that several short-term dives, performed before a long dive, allows seals to condition themselves. Measurements on the chemical compounds released to the blood during dives, combined with experiments on the genes that regulate them will provide clues on the biochemical pathways that help the seals tolerate these extreme conditions. The project allows for documentation of individual seal dives and provisioning of such information to the broader science community that seeks to study these seals, educating graduate and undergraduate students and a post-doctoral researcher and producing a science-outreach comic book for middle-school students to illustrate the project's science activities, goals and outcomes. Part II: Technical description: The Weddell seal is a champion diver with high natural tolerance for low blood oxygen concentration (hypoxemia) and inadequate blood supply (ischemia). The processes unique to this species protects their tissues from inflammation and oxidative stress observed in other mammalian tissues exposed to such physiological conditions. This project aims to understand the signatures of the processes that protect seals from inflammation and oxidant stress, using molecular, cellular and metabolic tools. Repetitive short dives before long ones are hypothesized to precondition seal tissues and activate the protective processes. The new aspect of this work is the study of endothelial cells, which sense changes in oxygen and blood flow, providing a link between breath-holding and cellular function. The approach is one of laboratory experiments combined with 2-years of field work in an ice camp off McMurdo Station in Antarctica. The study is structured by three main objectives: 1) laboratory experiments with arterial endothelial cells exposed to changes in oxygen and flow to identify molecular pathways responsible for tolerance of hypoxia and ischemia using several physiological, biochemical and genomic tools including CRSPR/Cas9 knochout and knockdown approaches. 2) Metabolomic analyses of blood metabolites produced by seals during long dives. And 3) Metabolomic and genomic determinations of seal physiology during short dives hypothesized to pre-condition tolerance responses. In the field, blood samples will be taken after seals dive in an isolated ice hole and its diving performance recorded. It is expected that the blood will contain metabolites that can be related to molecular pathways identified in lab experiments. Expert collaborators will provide field support, with the ice camp, dive hole for the seals, and telemetry associated with the seals’ dives. The project builds upon previous NSF-funded projects where the seal genome and cellular resources were produced. Undergraduate researchers will be recruited from institutional programs with a track record of attracting underrepresented minorities and a minority-serving institution. To further increase polar literacy training and educational impacts, the field team will include a blog where field experiences are shared and comic book preparation with an artist designed for K-12 students and public outreach.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.