摘要During cerebral ischemia-reperfusion injury(CIRI),endoplasmic reticulum stress(ERS)leads to the development and progression of a series of deleterious physiological responses such as oxidative stress,dis-turbed calcium ion homeostasis,inflammation,apoptosis and autophagy.The unfolded protein response(UPR)is the main pathway activated by ERS,which regulates the expression of related factors within the endoplasmic reticu-lum(ER)and reduces protein translation levels.Prolonged and intense ERS may lead to cell death.Excessive ERS induces apoptosis mediated by C/EBP homologous pro-tein(CHOP),caspase-12 and c-Jun N-terminal kinase(JNK),thereby exacerbating brain damage.The thresh-old for the transition from adaptive mechanisms to apop-totic mechanisms during ERS depends on multiple fac-tors,including the cell status and environment,signaling pathway activity status,cumulative cascade,and the dose and time of ERS inducers.Further research is needed to completely elucidate the mechanism of ERS.Although the factors associated with the PERK and ATF6 path-ways are less extensively studied,their regulators still exist.Deficiency of protein tyrosine phosphatase 1B(PTP1B)leads to increased phosphorylation of PERK-eIF2α,while regulation of the proteasome and regulation of the XBP1 target gene WFS1 may also affect ATF6 sta-bility.In addition,differences in the structure,gene expres-sion,and metabolism of different types of neurons,as well as in their internal environment,may lead to differ-ences in their response to and impact on ERS.Differenc-es in UPR signaling pathways occur in hippocampal neurons and medial thalamic cells,and Purkinje cells and pyramidal cells may be more sensitive to ERS than other types of neurons.Our group's previous study found that ERS induced apoptosis in neurons after the onset of CIRI by regulating proteins such as GRP78,CHOP and caspase-12,but the effects of UPR activation on different cells need to be further investigated.