Brandan E, Melo F, García M, Contreras M
Unidad de Neurobiología Molecular, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Casilla 114-D, Santiago, Chile.
Clin Mol Pathol. 1996 Dec;49(6):M351-6. doi: 10.1136/mp.49.6.m351.
Aims-To investigate whether proteoglycan synthesis is altered in skin fibroblasts in patients with Alzheimer's disease compared with normal subjects.Methods-Cell lines obtained from donors with Alzheimer's disease and healthy controls were incubated with radioactive sulphate. The proteoglycans synthesised were determined and analysed by chromatographic, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and glycosaminoglycans-lyase treatment. The amount of decorin synthesised by each cell line was quantified using western blot analysis. Transcripts for human decorin were determined using northern blot analysis.Results-No significant changes in total sulphate incorporation and glycos-aminoglycan (GAG) composition were detected in the incubation media of these cells. However, chromatographic and SDS-PAGE analysis of the proteoglycans secreted by the cell lines showed that a dermatan sulphate proteoglycan of 150-125 kilodaltons was substantially reduced in Alzheimer's disease fibroblasts. The molecular characteristics of this proteoglycan correspond to decorin. Western blot analysis indicated that decorin was reduced in Alzheimer's disease incubation medium compared with normal medium. Northern blotting indicated that in Alzheimer's disease fibroblasts decorin transcripts were significantly reduced compared with normal fibroblasts. Glypican concentrations, a cell surface heparan sulphate proteoglycan, remained the same.Conclusions-These results strongly suggest that the expression and synthesis of decorin is affected in Alzheimer's disease skin fibroblasts.
目的——研究与正常受试者相比，阿尔茨海默病患者皮肤成纤维细胞中的蛋白聚糖合成是否发生改变。方法——将从阿尔茨海默病患者供体和健康对照者获得的细胞系与放射性硫酸盐一起孵育。对合成的蛋白聚糖进行测定，并通过色谱法、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和糖胺聚糖-裂解酶处理进行分析。使用蛋白质印迹分析对每个细胞系合成的核心蛋白聚糖量进行定量。使用Northern印迹分析确定人核心蛋白聚糖的转录本。结果——在这些细胞的孵育培养基中未检测到总硫酸盐掺入和糖胺聚糖（GAG）组成的显著变化。然而，对细胞系分泌的蛋白聚糖进行的色谱分析和SDS-PAGE分析表明，阿尔茨海默病成纤维细胞中150 - 125千道尔顿的硫酸皮肤素蛋白聚糖显著减少。这种蛋白聚糖的分子特征与核心蛋白聚糖一致。蛋白质印迹分析表明，与正常培养基相比，阿尔茨海默病孵育培养基中的核心蛋白聚糖减少。Northern印迹表明，与正常成纤维细胞相比，阿尔茨海默病成纤维细胞中的核心蛋白聚糖转录本显著减少。磷脂酰肌醇蛋白聚糖浓度，一种细胞表面硫酸乙酰肝素蛋白聚糖，保持不变。结论——这些结果强烈表明，阿尔茨海默病皮肤成纤维细胞中核心蛋白聚糖的表达和合成受到影响。
