Rescue of protein dyshomeostasis in hippocampal astrocytes from an Alzheimer's disease mouse model by stabilizing ER-mitochondrial interactions at a 20 nm distance.

backgroundAlzheimer's disease (AD) is the major age-related form of dementia in which dysfunctional ubiquitin-proteasome system (UPS) and autophagy represent primary mechanisms leading to accumulation of misfolded proteins, dysfunction of astroglial cells, neuroinflammation and neurodegeneration. Alterations of the endoplasmic reticulum (ER)-mitochondria contact sites (MERCS), specifically the shortening of the distance between the organelles, was proposed as a key mechanism of cell dysfunction in AD. However, its link to the impairment of the proteolytic system in AD remains unexplored.

methodsWe used, as a model, hippocampal astrocytes from 3xTg-AD mice expressing either control plasmid or synthetic linkers stabilizing ER-mitochondrial interaction at 10 nm (10 nm-EML) or at 20 nm (20 nm-EML). Alternatively, astrocytes were treated with mitochondrial Ca

resultsStabilization of MERCS at 20 nm (20 nm-MERCS), which promotes mitochondrial Ca

conclusionsOur results suggest that disruption of ER-mitochondrial interaction is a key factor for AD-related dysregulation of protein degradation and provide a proof that stabilization of MERCS at a defined distance and/or pharmacological rescue of mitochondrial Ca