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

该奖项是根据2021年美国救援计划法案（公法117-2）资助的。第一部分：非技术说明： 威德尔海豹是南极洲的标志性物种，也是一名出色的潜水员，它能游到2,000英尺深的地方，并在水下停留长达45分钟。然而，对于任何哺乳动物来说，潜水过程中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数十年来吸引科学家的独特之处。这项研究项目将评估威德尔海豹的生理学的基本过程，保护这个物种免受潜水的后果。这项工作将结合联合收割机实验室实验，在实验中，血管细胞将暴露在低氧条件下，类似于在南极洲潜水海豹中测量的条件。研究人员将测试一个新的想法，即在长时间潜水之前进行几次短期潜水，让海豹适应自己。对潜水过程中释放到血液中的化合物的测量，以及对调节它们的基因的实验，将为帮助海豹忍受这些极端条件的生化途径提供线索。该项目允许记录个别海豹潜水，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，并为中学生制作科学宣传漫画书，以说明该项目的科学活动，目标和成果。第二部分：技术说明： 威德尔海豹是潜水冠军，对低血氧浓度（低氧血症）和血液供应不足（缺血）具有很高的天然耐受性。该物种特有的过程保护其组织免受在暴露于此类生理条件的其他哺乳动物组织中观察到的炎症和氧化应激。该项目旨在了解保护海豹免受炎症和氧化应激的过程的特征，使用分子，细胞和代谢工具。在长时间潜水之前重复的短时间潜水被假设为预处理密封组织并激活保护过程。这项工作的新方面是对内皮细胞的研究，内皮细胞可以感知氧气和血流的变化，从而将屏气和细胞功能联系起来。该方法是在南极洲麦默多站外的一个冰营地进行的2年实地工作与实验室实验相结合的方法之一。该研究由三个主要目标构成：1）使用暴露于氧气和流量变化的动脉内皮细胞的实验室实验，以使用几种生理学、生物化学和基因组工具（包括CRSPR/Cas9敲除和敲低方法）鉴定负责缺氧和缺血耐受性的分子途径。2)海豹长时间潜水时血液代谢产物的代谢组学分析。和3）代谢组学和基因组测定海豹生理在短期潜水假设的先决条件的耐受性反应。在野外，海豹在一个孤立的冰洞里潜水后将采集血液样本，并记录其潜水表现。预期血液将含有可能与实验室实验中鉴定的分子途径相关的代谢物。专家合作者将提供现场支持，包括冰营，海豹潜水孔以及与海豹潜水相关的遥测。该项目建立在以前NSF资助的项目的基础上，这些项目生产了海豹基因组和细胞资源。本科研究人员将从机构项目中招募，这些项目有吸引代表性不足的少数民族和少数民族服务机构的记录。为了进一步提高极地扫盲培训和教育影响，实地团队将包括一个博客，分享实地经验，并与一位为K-12学生设计的艺术家一起编写漫画书和公众宣传。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值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 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.