sphingosine-1-phosphate and Cognitive-Dysfunction

The timing and characteristics of neuronal death in Alzheimer's disease (AD) remain largely unknown. Here we examine AD mouse models with an original marker, myristoylated alanine-rich C-kinase substrate phosphorylated at serine 46 (pSer46-MARCKS), and reveal an increase of neuronal necrosis during pre-symptomatic phase and a subsequent decrease during symptomatic phase. Postmortem brains of mild cognitive impairment (MCI) rather than symptomatic AD patients reveal a remarkable increase of necrosis. In vivo imaging reveals instability of endoplasmic reticulum (ER) in mouse AD models and genome-edited human AD iPS cell-derived neurons. The level of nuclear Yes-associated protein (YAP) is remarkably decreased in such neurons under AD pathology due to the sequestration into cytoplasmic amyloid beta (Aβ) aggregates, supporting the feature of YAP-dependent necrosis. Suppression of early-stage neuronal death by AAV-YAPdeltaC reduces the later-stage extracellular Aβ burden and cognitive impairment, suggesting that preclinical/prodromal YAP-dependent neuronal necrosis represents a target for AD therapeutics.

Topics: Adaptor Proteins, Signal Transducing; Alzheimer Disease; Amyloid beta-Peptides; Animals; Cell Cycle Proteins; Cell Nucleus; Cognitive Dysfunction; Computer Simulation; Disease Models, Animal; Endoplasmic Reticulum; Female; HMGB1 Protein; Humans; Induced Pluripotent Stem Cells; Lysophospholipids; Male; Mice, Transgenic; Necrosis; Neurons; Signal Transduction; Sphingosine; Time-Lapse Imaging; Transcription Factors; YAP-Signaling Proteins