Endoplasmic reticulum stress as a novel neuronal mediator in Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common types of progressive dementias. The typical neuropathological changes in AD include extracellular senile plaques, intracellular neurofibrillary tangles, and loss of neurons. The pathogenetic mechanism of this disease is not comprehensively understood yet. Recently, endoplasmic reticulum stress (ER stress) has been considered as a potential event involved in AD development. Some AD-related factors, such as misfolded protein and Ca(2+) depletion, could disrupt the homeostasis of ER lumen. In AD, the aggregated amyloid-beta peptide (Abeta) could induce ER stress in an assembly dependent way. The presenilin has been identified as a Ca(2+) channel. Mutations of presenilin could change the balance of Ca(2+) in ER lumen and thus disrupts the ER homeostasis. Furthermore, the ER stress could lead to cellular disorders like inflammation. Through activating the expression of inflammatory factors, ER stress triggers inflammatory response in AD pathology. Herein, we reviewed the recent progress of ER stress-induced unfolded protein response (UPR) and the roles of ER stress in AD pathological process.