A Test of Leptin's Central Function in Zebrafish

描述（由申请人提供）：拟议研究的总体方法是使用比较方法来了解瘦素在人类糖尿病和肥胖症发展中的作用。我们将使用斑马鱼模型来测试瘦素功能的具体假设。在我们的上一个奖项中，我们确定了瘦素是正常斑马鱼发育所必需的，因为瘦素减少的斑马鱼胚胎不吸收蛋黄，感觉结构（眼睛和内耳）减少，脊索异常，心脏功能受损和代谢率降低。在这个更新的建议，我们将解决两个具体的目标，建立在我们以前的工作：I-我们将测试的假设，增加瘦素滴度激活脂肪动员从肝脏成年斑马鱼。我们将提高和降低成年斑马鱼的瘦素滴度，并测试肝脏中脂质催化剂的上调。II：我们将测试瘦素受体重叠转录本（LEPROT）的表达调节斑马鱼瘦素敏感性的假设。LEPROT负调节人类和其他哺乳动物中瘦素受体的细胞表面表达。其编码序列通过替代起始位点包含在瘦素受体基因内，并且其表达受瘦素受体启动子调节。在鱼类中，LEPROT的一级结构是保守的，但该基因与瘦素受体分离。我们将测试LEPROT功能是否在鱼类中保守。拟议的研究将在为年轻科学家提供培训机会的基础上进行。要求资金支持研究生和本科生，首席研究员、研究生和本科生将组成高中生志愿者指导小组。学生将参与动手研究，每个人都有自己独特的项目，有助于提案的总体目标。PI和合作研究者在赞助本科生研究方面有着良好的记录。使用斑马鱼模型的独立研究项目是其高级本科课程的核心（例如，细胞生理学，每年招收50名学生），PI重写了所有介绍性生物学实验室，以包括每个实验室的本科研究。PI还在他的家庭部门（现在是第7年）开始了本科研究研讨会，PI和Co-PI每年都会在他们的实验室赞助几个荣誉论文研究项目。最后，两位研究人员都成功地吸引了代表性不足的学生参加他们的研究项目，PI是NSF赞助的一个项目的成员，该项目致力于增加妇女和少数民族在STEM学科中的代表性（项目IDEAL）。 公共卫生相关性：拟议的研究调查激素瘦素在斑马鱼模式生物中的功能。这些研究的结果可能会导致更好地了解肥胖，代谢综合征和糖尿病如何在人类中发展，以及这些疾病的潜在治疗方法。

DESCRIPTION (provided by applicant): The overarching approach of the proposed research is to use the comparative method to understand leptin's role in the development of human diabetes and obesity. We will use the zebra fish model to test specific hypotheses about leptin function. In our last award, we established that leptin is required for normal zebra fish development, as zebra fish embryos with reduced leptin do not absorb yolk, have reduced sensory structures (eyes and inner ear), abnormal notochord, impaired cardiac function and lower metabolic rate. In this renewal proposal we will address two Specific Aims that build on our previous work: I- We will test the hypothesis that increased leptin titer activates lipid mobilization from liver in adult zebra fish. We will increase and decrease leptin titer in adult zebra fish and test for up-regulation of lipid catabolism in liver. II: We will test the hypothesisthat expression of the leptin receptor overlapping transcript (LEPROT) modulates leptin sensitivity in zebra fish. LEPROT negatively regulates cell-surface expression of the leptin receptor in humans and other mammals. Its coding sequence is contained within the leptin receptor gene via an alternate start site, and its expression is regulated by the leptin receptor promoter. In fishes, LEPROT's primary structure is conserved, but the gene is separated from the leptin receptor. We will test whether LEPROT function is conserved in fishes. The proposed research will be conducted with substantial consideration toward providing training opportunities for young scientists. Funds are requested to support graduate students and undergraduate students, and the lead investigators, graduate students, and undergraduate students will form a mentoring team for high school student volunteers. Students will be involved in hands-on research, each with their own distinct project that contributes to the overall goals of the proposal. The PI and Co-investigator have an excellent record of sponsoring undergraduate research. Independent research projects using the zebra fish model are central to their advanced undergraduate classes (e.g. Cell Physiology with an annual enrollment of 50), and the PI rewrote all introductory Biology laboratories to include undergraduate research in each laboratory. The PI also started an undergraduate research symposium in his home department (now in its 7th year) and both PI and Co-PI sponsor several Honors thesis research projects in their laboratories annually. Finally, both investigators have been successful in attracting underrepresented students into their research programs, and the PI is a member of an NSF-sponsored project dedicated to increasing representation of women and minorities in STEM disciplines (Project IDEAL). PUBLIC HEALTH RELEVANCE: The proposed studies investigate function of the hormone leptin in the zebra fish model organism. Results of these studies may lead to greater understanding of how obesity, metabolic syndrome, and diabetes develop in humans, as well as potential therapies for those diseases.