Mechanisms of Nicotine's Behavioral Effects on the HIV-1 Transgenic Rat

描述(申请人提供)：这项修订的研究方案的目标是确定尼古丁对因存在HIV-1病毒蛋白而导致的学习和记忆障碍的药理作用，并通过使用新创建的非传染性HIV-1转基因(HIV-1TG)大鼠模型来确定与这些影响相关的基因和生物学途径。虽然HIV-1基因gag和pol已被删除，但包括ltrs在内的其他病毒基因仍保持完整，并在HIV-1TG大鼠的脑和血液等大多数组织中表达。随着年龄的增长，这只HIV-1TG大鼠会出现人类HIV疾病的临床表现，因此，它模仿了由于宿主中持续存在HIV蛋白而导致的感染。当我们在改进的Morris水迷宫中测试HIV-1TG大鼠的表现时，它们显示出类似于HIV-1感染患者的空间学习缺陷。在人类和啮齿动物模型中进行的大量流行病学和基础研究表明，尼古丁可以增强认知能力，表明尼古丁具有神经保护作用。基于这些发现，我们假设HIV-1TG大鼠暴露于尼古丁可以改变由于HIV-1病毒蛋白在大鼠体内持续存在而导致的观察到的学习和认知障碍。为了验证这一假说，我们建议首先在行为水平上确定尼古丁对HIV-1TG大鼠的影响，然后确定尼古丁对HIV-1TG大鼠影响的基因和生物途径。最后，我们将描述尼古丁对HIV-1诱导的学习和记忆障碍的影响的特定基因和途径。具体地说，我们的目标是：1)利用带有导航非视觉线索的改进的Morris水迷宫测试来确定尼古丁对HIV-1TG大鼠学习和记忆的影响；2)使用高密度寡核苷酸芯片确定尼古丁对HIV-1TG大鼠学习和记忆的显著影响的生物通路；以及3)利用各种常规生物化学和分子生物学技术在RNA和蛋白质水平上鉴定与这些生物通路相关的特定基因，包括那些负责神经保护和神经炎症的基因，这些基因介导尼古丁对HIV-1TG大鼠学习和记忆的影响。据我们所知，这是第一次在啮齿动物模型中研究尼古丁对艾滋病毒-1病毒蛋白导致的学习和认知障碍的影响。拟议研究产生的数据将阐明尼古丁在艾滋病毒-1病毒蛋白存在的情况下影响学习行为的分子机制(S)，并在理解和治疗与艾滋病毒感染和艾滋病相关的神经功能障碍方面具有重要的临床意义。公共卫生相关性：这项拟议研究的主要目标是确定尼古丁对因存在HIV-1病毒蛋白而导致的学习和记忆障碍的药理学影响，并通过使用新创建的非传染性HIV-1转基因大鼠模型来确定与这些影响相关的基因和生物学途径。

DESCRIPTION (provided by applicant): The goal of this revised research proposal is to determine the pharmacologic effects of nicotine on the learning and memory deficits resulted from the presence of HIV-1 viral proteins and to define the genes and biological pathways associated with those effects by using a newly created non-infectious HIV-1 transgenic (HIV-1Tg) rat model. Although the HIV-1 genes gag and pol had been deleted, other viral genes including LTRs still kept intact and are expressed in most tissues including brain and blood of the HIV-1Tg rats. With advancing age, this HIV-1Tg rat develops clinical manifestations of human HIV disease, and, thus, mimics the infection that results from the persistent presence of HIV proteins in the host. When we examined the performance of HIV-1Tg rats in a modified Morris water maze, they showed deficits in spatial learning similar to those in patients with HIV-1 infection. Numerous epidemiological and basic research studies in both humans and rodent models reveal that nicotine can enhance cognitive abilities, indicating nicotine has neuroprotective effects. Based on these findings, we hypothesize that exposure of HIV-1Tg rats to nicotine can alter the observed learning and cognitive deficits resulted from the continuous presence of HIV-1 viral proteins in the rats. To test this hypothesis, we propose to first determine nicotine's effects in the HIV-1Tg rats at the behavioral level and then identify the genes and biological pathways that are affected by nicotine in the HIV-1Tg rats. Finally, we will characterize the specific genes and pathways that mediate nicotine's effects on HIV-1-induced learning and memory deficits. Specifically, our aims are: 1) To determine nicotine's effects on learning and memory in HIV-1Tg rats using a modified Morris water maze test with non-visual cues for navigation; 2) To identify the biological pathways that are significantly affected by nicotine in HIV-1Tg rats using high-density oligonucleotide microarray; and 3) To characterize the specific genes associated those biological pathways, including those are responsible for neuroprotection and neuroinflammation, that mediate nicotine's effects on learning and memory in HIV- 1Tg rats at both RNA and protein levels using various conventional biochemistry and molecular biology techniques. To our knowledge, this represents the first study of investigating how nicotine affects on learning and cognitive deficits resulted from the HIV-1 viral proteins in a rodent model. The data generated from the proposed studies will shed light on the molecular mechanism(s) underlying nicotine's effects on learning behaviors in the presence of HIV-1 viral proteins, and can have substantial clinical significance in the understanding and treatment of neurological dysfunctions associated with HIV infection and AIDS. PUBLIC HEALTH RELEVANCE: The primary goal of this proposed research is to determine the pharmacological effects of nicotine on the learning and memory deficits resulted from the presence of HIV-1 viral proteins and to define the genes and biological pathways associated with those effects by using a newly created non-infectious HIV-1 transgenic rat model.