EAPSI: Characterizing Regenerative Cells during Central Nervous System Regeneration in Marine Acorn Worms

EAPSI：表征海洋橡子蠕虫中枢神经系统再生过程中的再生细胞

• 批准号: 1614394
• 负责人: Shawn Luttrell
• 金额: $ 0.04万
• 依托单位: Luttrell Shawn M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1614394&HistoricalAwards=false
• 关键词: EAPSI; Characterizing; Regenerative; Cells; during

Central nervous system (CNS) regeneration remains on the forefront of scientific research after decades of study. Progress and advances have been made, however, many of the cellular mechanisms controlling CNS regeneration continue to be elusive. Millions of people suffer from debilitating neurological defects, like Alzheimer?s and Parkinson?s disease, spina bifida, epilepsy, and spinal cord injuries, to name a few. Furthermore, aging and age related diseases eventually affect everyone. Regeneration may slow the aging process and stem cells, which have the potential to become any type of cell in the body, including nerve cells, present one feasible way to combat neural diseases and injuries. The goal of this project is to determine whether bona fide stem cells are elaborating missing tissue during regeneration in marine acorn worms. Some species of acorn worms, like Ptychodera flava, completely regenerate their entire CNS after amputation. Understanding the mechanisms for regeneration in acorn worms may yield clues to unlocking regeneration in other animals with limited CNS regeneration, including humans. I will be working with Dr. Yi-Hsien Su at the Institute of Cellular and Organismic Biology at Academia Sinica in Taiwan on this project. She routinely collects and uses this animal for biological studies. Her lab specializes in gene networks regulating animal body plan evolution, development, and patterning using molecular techniques that target specific genes and cell types. This project may be a springboard that could give insights for new stem cell therapies and nerve regeneration in humans. Acorn worms, also known as hemichordates, are marine, invertebrate deuterostomes and sister group to the echinoderms. Acorn worms have a tripartite body plan with an anterior proboscis, a middle collar region, and a long posterior trunk. As deuterostomes, hemichordates share several morphological and developmental features with the chordates. The solitary hemichordate, Ptychodera flava, has a hollow, dorsal neural tube that develops in a very similar fashion to the chordate neural tube. Upon amputation, P. flava reliably regrows their entire neural tube and anterior head-like structure in about two weeks. No chordate has been shown to have this ability. Our lab has shown that extensive cell death and cell proliferation are activated during anterior regeneration in P. flava. It is not known whether bona fide stem cells are proliferating in this animal or whether somatic cells are de-differentiating and then becoming multi-potent to generate new structures. To help confirm the origin and identity of proliferating cells in P. flava, I will stain non-regenerating animals with antibodies raised against a hemichordate vasa protein. Vasa is a marker for germline stem cells across numerous animal phyla. Vasa is also expressed in some non-germline, multi-potent stem cells. I will also use in situ hybridization with the stem cell markers, c-Myc, pax6, and alkaline phosphatase. If expression of these markers co-localize with staining of vasa protein in non-germ cells, this will support a hypothesis of bona fide stem cells in P. flava. If this is confirmed, P. flava presents an exciting model to study the molecular mechanisms of stem cell recruitment and specification during central nervous system regeneration in the deuterostomes. Further experiments will be required to prove that the stem cells can self renew and also differentiate into other cell types during regeneration.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of Taiwan.

经过几十年的研究，中枢神经系统（CNS）再生仍然是科学研究的前沿。然而，控制中枢神经系统再生的许多细胞机制仍然是难以捉摸的。数以百万计的人患有衰弱的神经缺陷，比如阿尔茨海默病？s和帕金森？S病、脊柱裂、癫痫和脊髓损伤等等。此外，衰老和与年龄有关的疾病最终会影响到每个人。再生可能会减缓衰老过程，干细胞有可能成为体内任何类型的细胞，包括神经细胞，为对抗神经疾病和损伤提供了一种可行的方法。这个项目的目标是确定真正的干细胞是否在海洋橡子蠕虫再生过程中精心设计了缺失的组织。有些种类的橡子蠕虫，如黄斑果子虫，在截肢后可以完全再生它们的整个中枢神经系统。了解橡子蠕虫的再生机制可能会为解锁其他中枢神经系统再生有限的动物（包括人类）的再生提供线索。我将与台湾中央研究院细胞与有机体生物学研究所的苏以显博士合作进行这个项目。她经常收集并使用这种动物进行生物学研究。她的实验室专门研究调节动物身体计划进化、发育的基因网络，并使用针对特定基因和细胞类型的分子技术进行模式设计。这个项目可能是一个跳板，可以为新的干细胞疗法和人类神经再生提供见解。橡子蠕虫，也被称为半足虫，是海洋，无脊椎后口动物和棘皮动物的姐妹组。橡子虫有一个三部分的身体计划，包括一个前喙，一个中间的项圈区域和一个长长的后躯干。作为后口动物，半足动物与脊索动物有一些共同的形态和发育特征。单生半翅虫，Ptychodera flava，有一个中空的背侧神经管，其发育方式与脊索类神经管非常相似。在截肢后，黄芽孢杆菌在大约两周内可靠地重新长出整个神经管和前头状结构。没有脊索动物被证明有这种能力。我们的实验室已经证明，在黄芽孢杆菌的前再生过程中，广泛的细胞死亡和细胞增殖被激活。目前尚不清楚，究竟是真正的干细胞在这种动物体内增殖，还是体细胞去分化，然后变成多能的，从而产生新的结构。为了帮助确认黄芽孢杆菌中增殖细胞的起源和身份，我将用针对半果酸血管蛋白的抗体对非再生动物进行染色。Vasa是许多动物门中生殖系干细胞的标记物。Vasa也在一些非种系多能干细胞中表达。我还将使用干细胞标记物，c-Myc， pax6和碱性磷酸酶进行原位杂交。如果这些标记的表达与非生殖细胞中血管蛋白的染色共定位，这将支持黄芽孢杆菌中真正的干细胞的假设。如果这一结论得到证实，黄芽胞菌为研究后口动物中枢神经系统再生过程中干细胞募集和分化的分子机制提供了一个令人兴奋的模型。需要进一步的实验来证明干细胞可以自我更新，并在再生过程中分化成其他类型的细胞。该奖项隶属于东亚及太平洋暑期研究所项目，由美国国家科学基金会和台湾科技部共同资助，支持美国研究生的暑期研究。