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Local infusion of low dose erythropoietin (EPO) alleviates cerebral ischemia and reperfusion (I/R) injury in rats; however, the underlying molecular mechanisms are still unclear. The present study investigated the effect of low dose EPO treatment on I/R-induced endoplasmic reticulum (ER) stress in brain tissue and isolated microvessels in rodents. Sprague-Dawley rats were subjected to 2 h ischemia/24 h reperfusion by middle cerebral artery (MCA) occlusion, then administered fluorescein isothiocyanate-labeled EPO via MCA infusion (MCAI) or subcutaneous injection (SI) to compare the efficiency of two modes of delivery. Neurobehavioral deficits and infarct volume, and the expression of ER stress-associated proteins and apoptosis in brain tissue or isolated microvessels, as well as the transcriptional activity of 16 factors involved in ER stress and the unfolded protein response in brain tissue was asscessed. A higher EPO level in cerebrospinal fluid and brain tissue was observed in rats treated with EPO by MCAI (800 IU/kg) than by SI (5000 IU/kg). Moreover, neurobehavioral deficits and infarct volume were reduced in rats treated with EPO by MCAI and salubrinal. EPO suppressed the expression of ER stress signals glucose-regulated protein 78, activating transcription factor (ATF) 6α, and CCAAT enhancer-binding protein homologous protein (CHOP), as well as that of the pro-apoptotic protein caspase-3 in brain microvessels, and decreased the number of CHOP-positive, apoptotic neurons. EPO treatment also reduced the transcriptional activities of CHOP, forkhead box protein O1, and ATF4. These results provide evidence that low dose EPO treatment via MCAI provides neuroprotection following acute ischemic stroke by inhibiting the ER stress response. [ABSTRACT FROM AUTHOR]

GM-1 ganglioside (GM-1) has been proposed as a new therapeutic agent against Alzheimer's disease (AD). Therefore, in this study we aimed to investigate the effects of GM1 on memory deficits and oxidative stress in the hippocampus of rat model of AD. Wistar rats were randomly divided into three groups ( n = 15): control group, model group, and treatment group, which were injected with vehicle, Aβ1-40, and Aβ1-40 together with GM-1, respectively. Morris water maze test was performed to evaluate spatial learning and memory of the rats. Brain malondialdehyde (MDA) content was detected by biochemical assay, and 4-hydroxynonenal (4-HNE) level in the hippocampus was examined by immunohistochemistry. The results showed that learning and memory deficits were improved in treatment group compared to model group. Brain MDA content and 4-HNE level in hippocampus CA1 were much lower in treatment group than in model group. In summary, we demonstrate that GM-1 could improve spatial learning and memory deficits in rat model of AD, and this may be mediated by the inhibition of oxidative stress and lipid peroxidation in the neurons. These data suggest that GM-1 is a potential agent for AD treatment. [ABSTRACT FROM AUTHOR]