Department of Clinical Neurosciences, Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom.
PLoS One. 2010 Nov 11;5(11):e13947. doi: 10.1371/journal.pone.0013947.
Intracellular filamentous deposits containing microtubule-associated protein tau constitute a defining characteristic of many neurodegenerative disorders. Current experimental models to study tau pathology in vitro do not usually recapitulate the tau expression pattern characteristic of adult human brain. In this study, we have investigated whether human embryonic stem cell-derived neurons could be a good model to study human tau distribution, function and dysfunction.
METHODOLOGY/PRINCIPAL FINDINGS: Using RT-PCR, immunohistochemistry, western blotting and cell transfections we have investigated whether all 6 adult human brain tau isoforms are expressed in neurons derived from human embryonic and fetal stem cells and whether 4 repeat tau over-expression alone, or with the F3 tau repeat fragment, (amino acid 258-380 of the 2N4R tau isoform with the ΔK280 mutation) affects tau distribution. We found that the shortest 3 repeat tau isoform, similarly to human brain, is the first to be expressed during neuronal differentiation while the other 5 tau isoforms are expressed later. Over expression of tau with 4 repeats affects tau cellular distribution and the short tau F3 fragment appears to increase tau phosphorylation but this effect does not appear to be toxic for the cell.
Our results indicate that human embryonic stem cell-derived neurons express all 6 tau isoforms and are a good model in which to study tau physiology and pathology.
含有微管相关蛋白 tau 的细胞内丝状沉积物是许多神经退行性疾病的一个明确特征。目前用于体外研究 tau 病理学的实验模型通常不能重现成人脑中特有的 tau 表达模式。在这项研究中，我们研究了人类胚胎干细胞衍生的神经元是否可以成为研究人类 tau 分布、功能和功能障碍的良好模型。
方法/主要发现：使用 RT-PCR、免疫组织化学、western blot 和细胞转染，我们研究了所有 6 种成人脑中的 tau 异构体是否在源自人类胚胎和胎儿干细胞的神经元中表达，以及单独过表达 4 重复 tau 或与 F3 tau 重复片段（2N4R tau 异构体的 258-380 个氨基酸，带有 ΔK280 突变）是否会影响 tau 分布。我们发现，最短的 3 重复 tau 异构体与人类大脑相似，是在神经元分化过程中最早表达的，而其他 5 种 tau 异构体则较晚表达。4 重复 tau 的过表达会影响 tau 的细胞内分布，短 tau F3 片段似乎会增加 tau 的磷酸化，但这种效应似乎对细胞没有毒性。
我们的结果表明，人类胚胎干细胞衍生的神经元表达所有 6 种 tau 异构体，是研究 tau 生理学和病理学的良好模型。
