Adverse Actions of Stimulants on Embryonic Development and Energetics

描述(由申请人提供)：长期目标是确定滥用药物如何扰乱线粒体能量学，并在以后的生命中损害胚胎发育和健康。胚胎发育的时间与能量(ATP)代谢高度调节和协调。初步数据显示，通过遗传手段或通过暴露于滥用药物而抑制线粒体能量学会导致神经和心血管系统发育的特定缺陷，这些系统需要很高的能量，因此依赖于线粒体功能。经常滥用的ADHD药物，如哌醋甲酯(MPH)、安非他明和甲基苯丙胺(METH)影响能量代谢，MRC的蛋白质水平下降揭示了这一点。然而，测量呼吸的功能研究还没有进行。此外，这些药物在胚胎发育中影响线粒体能量学的机制尚不清楚。这种认识上的差距是由于缺乏测量胚胎发育过程中的能量学的方法。PI的实验室已经开发出一种创新的高通量测试方法，用于测量斑马鱼胚胎的呼吸和生物能量学，该方法利用了斑马鱼胚胎的小尺寸、母鱼外胚胎的发育以及每对繁殖对产生的胚胎的绝对数量(100个)。对于拟议的研究来说，这种分析是不可或缺的。胎儿期接触PMH或冰毒的长期影响尚不清楚。研究很重要，因为在18-49岁的美国人口中，非法冰毒的终生流行率超过8%，而且冰毒的使用与危险的性行为、怀孕和成年后持续的行为障碍有关。这些数据，以及我们的初步工作，让我们检验了我们的中心假设：产前暴露于mph或冰毒会损害细胞能量，扰乱具有最高能量需求的组织的发育，导致长期的行为缺陷。这项研究的基本原理是，了解mph/冰毒引起的线粒体功能障碍是如何导致胚胎缺陷的，将指导开发新的治疗策略来预防出生缺陷。这一假说将通过追求两个具体目标来检验：1)确定mph或冰毒暴露扰乱斑马鱼胚胎细胞能量学的机制；2)确定mph和冰毒对斑马鱼发育和行为的影响。这项拟议的研究意义重大，因为这些研究将阐明产前暴露于mph或冰毒导致神经行为缺陷的机制。然后，这些斑马鱼模型可以作为高通量筛选，用于逆转能量和发育缺陷的候选药物疗法。预防兴奋剂滥用造成的出生缺陷将极大地改善这些儿童的生活质量和整个人类健康。

DESCRIPTION (provided by applicant): The long-term goal is to determine how drugs of abuse disrupt mitochondrial energetics and harm embryonic development and health in later life. The timing of embryonic development is highly regulated and coordinated with energy (ATP) metabolism. Preliminary data reveal that inhibition of mitochondrial energetics via genetic means or by exposures to abused drugs cause specific defects in the development of the nervous and cardiovascular systems, which have high energy requirements and are thus dependent on mitochondrial function. Commonly abused ADHD drugs such as methylphenidate (MPH), amphetamine and methamphetamine (METH) impact energy metabolism, as revealed by decreased protein levels of the MRC. However, functional studies to measure respiration have not been performed. Furthermore, the mechanisms by which these drugs impact mitochondrial energetics in embryonic development are elusive. This gap in knowledge is due to the lack of methodology for measuring energetics in developing embryos. The PI's laboratory has developed an innovative high-throughput assay to measure respiration and bioenergetics in zebrafish embryos that takes advantage of the small size of zebrafish embryos, development of embryos outside of the mother, and sheer numbers (100s) of embryos produced by each breeding pair. This assay is indispensable for the proposed studies. The long-term effects of prenatal exposures to MPH or METH are poorly understood. It is important to study, because the lifetime prevalence of illicit METH use in the US population aged 18-49 exceeds 8%, and METH use is associated with risky sexual behavior, pregnancy and persistent behavioral impairments in adulthood. These data, along with our preliminary work leads us to test our central hypothesis: Prenatal exposures to MPH or METH compromise cellular energetics, disrupting the development of tissues that have the highest energetic requirements, resulting in long-term behavioral defects. The rationale for this research is that understanding how mitochondrial dysfunction caused by MPH/METH leads to embryonic defects will guide the development of new treatment strategies to prevent birth defects. This hypothesis will be tested by pursuing two Specific Aims: 1) Determine the mechanism by which MPH or METH exposure disrupts cellular energetics in zebrafish embryos; and 2) Determine the effects of MPH and METH on zebrafish development and behavior. The proposed research is significant, because these studies will elucidate the mechanisms by which prenatal exposures to MPH or METH cause neurobehavioral defects. These zebrafish models can then serve as high-throughput screens for candidate pharmacotherapies that reverse energetic and developmental defects. Preventing birth defects caused by stimulant abuse will vastly improve the quality of life for these children and human health in general.