Neuronal apoptosis is an important pathophysiological factor of Alzheimer's disease (AD). Inhibition of endoplasmic reticulum stress (ERS)-induced neuronal apoptosis is an effective strategy to deal with AD. In this commentary, we summarize the relationship between AD and ERS injury-induced neuronal apoptosis, and highlight the protective effects and mechanism of isorhamnetin (Iso) against ERS-induced injury in N2a cells. Moreover, this commentary discusses the recent findings in the role of Iso in other diseases.Alzheimer's disease (AD) is a chronic neurodegenerative disease, and the fourth leading cause of death, behind heart disease, cancer and stroke
1. The clinical manifestations of AD include deteriorating cognitive function and memory, a decline in functioning in daily life activities, anda variety of neuropsychiatric symptoms and behavioral disorders 2,3 . The risk of AD gradually increases with age. There are more than 30 million AD patient living in the world today 4,5 .The etiology and pathogenesis of AD is not clear. AD is characterized by the accumulation of misfolded β-amyloid proteins caused by various genetic and environmental factors. These Aβ-plaques are associated with several pathological changes including the aggregation of misfolded proteins, formation of tissue precipitation, intracellular calcium disturbance, DNA fragmentation and lipid peroxidation. Together, these factors induce neuronal apoptosis and necrosis 6 . Thus, inhibiting neuron apoptosis is an effective way to prevent AD.The endoplasmic reticulum (ER) is theprincipal organelle for protein synthesis, protein folding and maintenance of calcium homeostasis 7 . Numerous stimuli, such as hypoxia and oxidative stress, can perturb calcium balance, and promote accumulation of unfolded and misfolded proteins in the ER lumen. This is known as endoplasmic reticulum stress (ERS) 8 . ERS is one of the key drivers of apoptosis. ERS induces apoptosis, through activation of the ASK and p38 MAPK signal pathway, trigger the kinase function of IRE1 [9][10][11] . Additionally, p38MAPK is reported to promote phosphorylation and activation of pro-apoptotic protein Bax 12,13 . Recent studies suggest that AD pathology is associated with ERS 14 . ERS generates a toxic environment in neurons, which in turn activates endoplasmic reticulum pathways that ultimately cause apoptosis 15 . Thus, inhibition of ERS injury may be an effective strategy to prevent AD.