Ginsberg S D, Crino P B, Lee V M, Eberwine J H, Trojanowski J Q
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104-4283, USA.
Ann Neurol. 1997 Feb;41(2):200-9. doi: 10.1002/ana.410410211.
The polypeptide composition of neurofibrillary tangles (NFTs) and senile plaques (SPs) has been characterized extensively within the Alzheimer's disease (AD) brain. Because few data exist on the nonproteinaceous components of these lesions, we sought to determine if NFTs, neuropil threads (NTs), and SPs contain RNA species. To accomplish this, acridine orange (AO) histofluorescence was employed, alone or in combination with thioflavine S (TS) staining and immunohistochemistry to identify RNAs in paraffin-embedded tissue sections of hippocampus and entorhinal cortex. Postmortem brain samples came from 32 subjects including AD and elderly Down's syndrome (DS) patients, age-matched normal controls, and non-AD diseased controls. AO stained the cytoplasm of normal hippocampal and entorhinal neurons in all of the cases, while NFTs, NTs, and SPs were AO-positive in the same regions of AD and DS brains. Cytoplasmic AO histofluorescence was abolished with RNase, but not DNase or proteinase K, indicating the relative specificity of AO for RNA species. Quantitative analysis of double-labeled sections demonstrated that approximately 80% of TS-positive NFTs also were AO-positive, whereas approximately 55% of TS-stained SPs contained AO labeling. These novel observations demonstrate the presence of RNAs in NFTs, NTs, and SPs.
神经原纤维缠结（NFTs）和老年斑（SPs）的多肽组成在阿尔茨海默病（AD）脑内已得到广泛表征。由于关于这些病变中非蛋白质成分的数据很少，我们试图确定NFTs、神经毡丝（NTs）和SPs中是否含有RNA种类。为实现这一目的，单独或联合使用硫黄素S（TS）染色及免疫组化，采用吖啶橙（AO）组织荧光法来鉴定海马体和内嗅皮质石蜡包埋组织切片中的RNA。尸检脑样本来自32名受试者，包括AD患者、老年唐氏综合征（DS）患者、年龄匹配的正常对照以及非AD疾病对照。在所有病例中，AO均对正常海马体和内嗅神经元的细胞质进行了染色，而在AD和DS脑的相同区域，NFTs、NTs和SPs呈AO阳性。用核糖核酸酶可消除细胞质AO组织荧光，但脱氧核糖核酸酶或蛋白酶K则不能，这表明AO对RNA种类具有相对特异性。对双标记切片的定量分析表明，约80%的TS阳性NFTs也呈AO阳性，而约55%的TS染色SPs含有AO标记。这些新发现证明了NFTs、NTs和SPs中存在RNA。
