Department of Pathology and Experimental Therapeutics, Network Centre of Biomedical Research of Neurodegenerative Diseases (CIBERNED), Institute of Health Carlos III, University of Barcelona, 08907 Barcelona, Spain.
Bellvitge University Hospital, Bellvitge Biomedical Research Institute (IDIBELL), Calle Feixa Llarga sn, 08907 Barcelona, Spain.
Int J Mol Sci. 2022 Jun 8;23(12):6427. doi: 10.3390/ijms23126427.
Altered protein phosphorylation is a major pathologic modification in tauopathies and Alzheimer's disease (AD) linked to abnormal tau fibrillar deposits in neurofibrillary tangles (NFTs) and pre-tangles and β-amyloid deposits in AD. hTau transgenic mice, which express 3R and less 4R human tau with no mutations in a murine knock-out background, show increased tau deposition in neurons but not NFTs and pre-tangles at the age of nine months. Label-free (phospho)proteomics and SWATH-MS identified 2065 proteins in hTau and wild-type (WT) mice. Only six proteins showed increased levels in hTau; no proteins were down-regulated. Increased tau phosphorylation in hTau was detected at Ser199, Ser202, Ser214, Ser396, Ser400, Thr403, Ser404, Ser413, Ser416, Ser422, Ser491, and Ser494, in addition to Thr181, Thr231, Ser396/Ser404, but not at Ser202/Thr205. In addition, 4578 phosphopeptides (corresponding to 1622 phosphoproteins) were identified in hTau and WT mice; 64 proteins were differentially phosphorylated in hTau. Sixty proteins were grouped into components of membranes, membrane signaling, synapses, vesicles, cytoskeleton, DNA/RNA/protein metabolism, ubiquitin/proteasome system, cholesterol and lipid metabolism, and cell signaling. These results showed that over-expression of human tau without pre-tangle and NFT formation preferentially triggers an imbalance in the phosphorylation profile of specific proteins involved in the cytoskeletal-membrane-signaling axis.
蛋白质磷酸化的改变是tau 病和阿尔茨海默病（AD）的主要病理改变，与神经原纤维缠结（NFT）和预缠结中的异常 tau 纤维沉积以及 AD 中的 β-淀粉样蛋白沉积有关。在敲除小鼠背景下表达 3R 和较少 4R 人类 tau 且没有突变的 hTau 转基因小鼠在 9 个月大时显示神经元中 tau 沉积增加，但 NFT 和预缠结没有增加。无标记（磷酸化）蛋白质组学和 SWATH-MS 在 hTau 和野生型（WT）小鼠中鉴定了 2065 种蛋白质。只有六种蛋白质在 hTau 中水平升高；没有蛋白质下调。在 hTau 中检测到 tau 的 Ser199、Ser202、Ser214、Ser396、Ser400、Thr403、Ser404、Ser413、Ser416、Ser422、Ser491 和 Ser494 的磷酸化增加，除了 Thr181、Thr231、Ser396/Ser404，但 Ser202/Thr205 没有。此外，在 hTau 和 WT 小鼠中鉴定了 4578 个磷酸肽（对应于 1622 个磷酸蛋白）；hTau 中有 64 种蛋白质发生差异磷酸化。60 种蛋白质被分为膜成分、膜信号、突触、囊泡、细胞骨架、DNA/RNA/蛋白质代谢、泛素/蛋白酶体系统、胆固醇和脂质代谢以及细胞信号。这些结果表明，人类 tau 的过度表达而没有预缠结和 NFT 形成优先触发涉及细胞骨架-膜信号轴的特定蛋白质磷酸化谱的不平衡。
