CALBINDIN-D28K--ROLE IN NEURODEGENERATION

Calbindin-D28k(CABP)，一种钙结合蛋白，存在于 大脑和脊髓中确定的神经元群体，似乎 保护细胞免受钙介导的细胞退化。已找到CABP 在海马神经元中，避免了由 实验诱发癫痫发作和兴奋性毒素。不具有这种功能的神经元 含有CABP的似乎是由于细胞内毒素水平而死亡 CA2.我们实验室的最新数据表明，特定的中脑 含钙结合蛋白的多巴胺能神经元在患者体内得到保存 帕金森氏症，并在猴子和小鼠中使用1-甲基- 4-苯基-1，2，3，6-四氢吡啶(MPTP)，是一种能产生 帕金森综合症)。然而，那些不包含 CABP最容易感染帕金森氏症和MPTP。目的 目前的拨款是-确定CABP是否保护中脑DA MPTP对小鼠神经元的神经毒性作用。首先，我们将 CABP免疫组织化学染色、计算机成像、原位CABP 杂交、~(14)C-MPTP体内放射自显影和单胺 测定内源性CABP的生化检测技术 保护特定的中脑DA神经元免受MPTP诱导的变性。 其次，我们将开发动物模型来测试保护性 CABP诱导表达MPTP转基因小鼠的抗MPTP作用 CABP存在于所有中脑DA神经元中。我们将使用酪氨酸 羟基酶启动子和神经元特异性烯醇化酶启动子的表达 并确定该蛋白的存在是否会 特别保护中脑对MPTP敏感的区域(实质 黑猩猩)。这些实验将：(I)确定CABP是否能保护 来自MPTP诱导的帕金森病的中脑DA神经元；和(2)提供 钙介导的其他神经退行性疾病的动物模型 神经退行性变可能是主要的病因(例如，阿尔茨海默氏症 疾病、亨廷顿氏病)。

Calbindin-D28k (CaBP), a calcium-binding protein that is present in defined neuronal populations in the brain and spinal cord, appears to protect cells from calcium-mediated cellular degeneration. CaBP is found in the hippocampal neurons that are spared cell loss caused by experimentally induced seizures and excitotoxins. The neurons that do not contain CaBP appear to die as a result of toxic levels of intracellular Ca2+. Recent data from our laboratory indicate that the specific midbrain dopaminergic (DA) neurons that contain CaBP are preserved in patients with Parkinson's disease, and in monkeys and mice treated with 1-methyl- 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, a neurotoxin which produces a parkinsonian syndrome). However, those DA neurons that do not contain CaBP are most vulnerable to Parkinson's disease and MPTP. The purpose of the present grant is-to determine whether CaBP protects midbrain DA neurons from the neurotoxic effects of MPTP in the mouse. First, we will use immunohistochemical staining for CaBP, computer imaging, CaBP in situ hybridization, 14C-MPTP in vivo autoradiography, and monoamine biochemical measuring techniques to determine whether endogenous CaBP protects specific midbrain DA neurons from MPTP-induced degeneration. Secondly, we will develop animal models in which to test the protective effects of CaBP against MPTP by generating transgenic mice which express CaBP within all of the midbrain DA neurons. We will use the tyrosine hydroxylase promoter and the neuron specific enolase promoter to ex-press CaBP, and determine whether the presence of this protein will specifically protect MPTP-sensitive areas of the midbrain (substantia nigra). These experiments will: (I) determine whether CaBP protects midbrain DA neurons from MPTP-induced parkinsonism; and (2) provide animal models of other neurodegenerative diseases where calcium-mediated neurodegeneration may play a major etiologic role (e.g., Alzheimer's disease, Huntington's disease).