La Rosa Luca Rosario, Perrone Lorena, Nielsen Morten Schallburg, Calissano Pietro, Andersen Olav Michael, Matrone Carmela
Institute of Cellular Biology and Neurobiology, National Council of Research of Rome , Rome , Italy.
Laboratory CiMoTheMA EA 3808, Faculty of Medicine and Pharmacy, University of Poitiers , Poitiers , France.
Front Cell Neurosci. 2015 Apr 7;9:109. doi: 10.3389/fncel.2015.00109. eCollection 2015.
The intracellular transport and localization of amyloid precursor protein (APP) are critical determinants of APP processing and β-amyloid peptide production, thus crucially important for the pathophysiology of Alzheimer's disease (AD). Notably, the C-terminal Y682ENPTY687 domain of APP binds to specific adaptors controlling APP trafficking and sorting in neurons. Mutation on the Y682 residue to glycine (Y682G) leads to altered APP sorting in hippocampal neurons that favors its accumulation in intracellular compartments and the release of soluble APPα. Such alterations induce premature aging and learning and cognitive deficits in APP Y682G mutant mice (APP (YG/YG) ). Here, we report that Y682G mutation affects formation of the APP complex with sortilin-related receptor (SorLA), resulting in endo-lysosomal dysfunctions and neuronal degeneration. Moreover, disruption of the APP/SorLA complex changes the trafficking pathway of SorLA, with its consequent increase in secretion outside neurons. Mutations in the SorLA gene are a prognostic factor in AD, and changes in SorLA levels in cerebrospinal fluid are predictive of AD in humans. These results might open new possibilities in comprehending the role played by SorLA in its interaction with APP and in the progression of neuronal degeneration. In addition, they further underline the crucial role played by Y682 residue in controlling APP trafficking in neurons.
淀粉样前体蛋白(APP)的细胞内运输和定位是APP加工及β-淀粉样肽生成的关键决定因素,因此对阿尔茨海默病(AD)的病理生理学至关重要。值得注意的是,APP的C末端Y682ENPTY687结构域与控制APP在神经元中运输和分选的特定衔接蛋白结合。Y682残基突变为甘氨酸(Y682G)会导致海马神经元中APP分选改变,使其更易在细胞内区室积累并释放可溶性APPα。这种改变会导致APP Y682G突变小鼠(APP(YG/YG))过早衰老以及学习和认知缺陷。在此,我们报告Y682G突变会影响APP与sortilin相关受体(SorLA)形成复合物,导致内溶酶体功能障碍和神经元变性。此外,APP/SorLA复合物的破坏会改变SorLA的运输途径,进而导致其在神经元外的分泌增加。SorLA基因的突变是AD的一个预后因素,脑脊液中SorLA水平的变化可预测人类的AD。这些结果可能为理解SorLA在其与APP相互作用及神经元变性进展中所起的作用开辟新的可能性。此外,它们进一步强调了Y682残基在控制神经元中APP运输方面所起的关键作用。