Up-Regulated Phospho-Stat3 In Ischemia Reperfusion Rat Model And Oxygen And Glucose Deprivation Cell Model

Signal transducer and activator of transcription factor 3 (STAT3), a member of the STAT protein family, plays a key role in neuroprotective when being activated through phosphorylation. However, the expression pattern of phospho-STAT3 (p-STAT3) in ischemic stroke remains poorly understood. Here we investigated the expression pattern and subcellular distribution of p-STAT3 in focal cerebral ischemia reperfusion rat model and oxygen and glucose deprivation (OGD) cell model using Western blot analysis and immunofluorescence staining. In Vitro, compared to control and sham-operated groups, Western blot analysis revealed that the p-STAT3 protein was significantly up-regulated in ischemic side hippocampus after ischemia reperfusion 24 hour. At the same time, immunofluorescence staining showed that the distribution of p-STAT3 was shifted from the cytoplasm to the nucleus at ischemia reperfusion 7 day. In vivo, the expression of p-STAT3 protein was increased in cultured neurons after OGD treated 1 hour, and reached its peak at OGD treated 3 hour. Also, OGD treatment promoted nuclear translocation of p-STAT3 in cultured neurons. Taken together, up-regulated expression of p-STAT3 protein in the ischemia reperfusion rat model and OGD cell model suggested that STAT3 was excessively activated by ischemia reperfusion and OGD, and p-STAT3 might be involved in the pathogenesis of ischemic stroke.