Expression of mutant amyloid precursor proteins decreases adhesion and delays differentiation of Hep-1 cells.
Expression of mutant amyloid precursor proteins decreases adhesion and delays differentiation of Hep-1 cells.
复制标题
突变淀粉样前体蛋白的表达会降低 Hep-1 细胞的粘附并延迟分化。
DOI：
10.1016/s0006-8993(01)02153-9
复制
发表时间：
2001
期刊：
影响因子：
2.9
通讯作者：
Zhao,B
中科院分区：
文献类型：
--
作者：
Kusiak,JW;Lee,LL;Zhao,B
淀粉样前体蛋白（APP）是一种I型整合膜蛋白，经加工后产生几个细胞内和分泌片段。APP及其加工片段的生理作用尚不清楚。在APP中已经发现了几种突变，其是早发性家族性神经系统疾病（包括阿尔茨海默病（FAD））的病因。这些突变改变了APP的加工过程，导致A-β肽（Aβ）的过量产生和细胞外沉积。我们已经研究了APP在内皮细胞功能的细胞培养模型中的作用。内皮细胞系Hep-1用野生型（wt）和FAD突变型APP（mAPP）稳定转染。当这些细胞在几种不同的基质上生长时，过表达mAPP的细胞系中sAPPα的分泌减少。在突变细胞系中通过ELISA测量分泌的Aβ水平增加。在所有表达mAPP的细胞系中，细胞与层粘连蛋白、纤连蛋白、胶原I和胶原IV包被的培养瓶的粘附性降低，而在过度表达wt-APP的细胞系中，粘附性略有增加。在Matrigel™上，过表达mAPP的细胞系比表达wt-APP的细胞系更慢地分化成毛细血管网络样结构。结果表明，APP可能在细胞增殖和内皮细胞成熟为毛细血管样网络中发挥作用。突变细胞系中粘附和分化的减少可能是由于释放到培养基中的sAPPα量减少或细胞外Aβ增加的毒性作用。
The amyloid precursor protein (APP) is a type I integral membrane protein and is processed to generate several intra-cellular and secreted fragments. The physiological role of APP and its processed fragments is unclear. Several mutations have been discovered in APP, which are causative of early-onset, familial, neurological disease, including Alzheimer’s disease (FAD). These mutations alter the processing of APP and lead to excess production and extra-cellular deposition of A-beta peptide (Aβ). We have examined the role of APP in a cell culture model of endothelial cell function. The endothelial cell line, Hep-1, was stably transfected with wild-type (wt) and FAD mutant forms of APP (mAPP). Secretion of sAPPα was reduced in cell lines over-expressing mAPP when these cells were grown on several different substrates. Levels of secreted Aβ were increased as measured by ELISA in the mutant cell lines. Cell adhesion to laminin-, fibronectin-, collagen I-, and collagen IV-coated culture flasks was reduced in all mAPP-expressing cell lines, while in lines over-expressing wt-APP, adhesiveness was slightly increased. Cell lines over-expressing mAPP differentiated more slowly into capillary network-like structures on Matrigel™ than those expressing wt-APP. No differences were detected among all cell lines in a migration/invasion assay. The results suggest that APP may have a role in cell adhesiveness and maturation of endothelial cells into capillary-like networks. The reduction in adhesion and differentiation in mutant cell lines may be due to reduced amounts of sAPPα released into the culture media or toxic effects of increased extracellular Aβ.