CALBINDIN-D28K--ROLE IN NEURODEGENERATION

钙结合蛋白-D28 k（CaBP），一种存在于 在大脑和脊髓中定义的神经元群体，似乎 保护细胞免受钙介导的细胞变性。发现CaBP 在海马神经元中， 实验性癫痫和兴奋性毒素而那些没有 含有CaBP的细胞似乎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， 含有CaBP的多巴胺能（DA）神经元在患者中被保留 帕金森氏病，以及在猴子和小鼠治疗1-甲基- 4-苯基-1，2，3，6-四氢吡啶（MPTP），一种神经毒素， 帕金森综合征）。然而，那些不含多巴胺的神经元 CaBP是最容易受到帕金森病和MPTP。的目的 目前资助是确定CaBP是否保护中脑DA 神经元的MPTP在小鼠的神经毒性作用。一是 应用免疫组化法检测CaBP，计算机成像，CaBP原位 杂交、14 C-MPTP体内放射自显影和单胺 生物化学测量技术，以确定内源性CaBP是否 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，以测试保护性 通过产生表达MPTP的转基因小鼠， 所有中脑DA神经元内的CaBP。我们将使用酪氨酸 羟化酶启动子和神经元特异性烯醇化酶启动子来表达 CaBP，并确定这种蛋白质的存在是否会 特异性保护中脑的MPTP敏感区域（实质 nigra）。这些实验将：（I）确定CaBP是否保护 中脑DA神经元从MPTP诱导的帕金森病;和（2）提供 其他神经退行性疾病的动物模型， 神经变性可能起主要的病因作用（例如，阿尔茨海默 疾病，亨廷顿病）。

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).