Electroacupuncture Improves Cerebral Ischemic Injury by Enhancing the EPO-JAK2-STAT5 Pathway in Rats

OBJECTIVE: Clinically, electroacupuncture (EA) improves cerebral ischemic injury, but its mechanism remains unknown. The aim of this study was to confirm the protective effects of EA on focal cerebral ischemia (FCI)-induced injury and the possible mechanism. METHODS: Sprague-Dawley (SD) rats served as the FCI model and were divided into the sham, model, EA, AG490 and EA+AG490 groups. Rats in the EA and EA+AG490 groups were acupunctured at the Baihui (GV20) and Dazhui (GV14) acupoints, and those in the AG490 and EA+AG490 groups were administered an intracerebroventricular injection of AG490 (a Janus-tyrosine kinase-2 (JAK-2) phosphorylation inhibitor). Neurological deficits and morphological changes in the ischemic cortex were observed through neurological deficit scoring and HE staining, respectively, and neuronal apoptosis was examined using the TUNEL assay. Transmission electron microscopy was used to observe neuronal ultrastructure, and HIF-1α, erythropoietin (EPO), phosphorylated (p)-JAK2, p-STAT5, HSP70, Bax and Bcl-2 expression was measured by RT-PCR and immunohistochemistry. RESULTS: FCI model rats showed obvious neurological deficits and neuronal apoptosis compared with sham rats. EA alleviated FCI-induced neurological deficits, improved neuronal ultrastructure, reduced neuronal apoptosis, and induced HIF-1α, EPO, p-JAK2, p-STAT5, HSP70 and Bcl-2 expression in a time-dependent manner. In contrast, AG490 treatment impaired the effects of EA on neurological deficits, neuronal apoptosis and HIF-1α, EPO, p-JAK2, p-STAT5, HSP70, Bax and Bcl-2 expression. CONCLUSION: EA at GV20 and GV14 could improve neurological deficits and reduce neuronal apoptosis, thereby improving FCI-induced injury, which may be related to enhancing the EPO-JAK2-STAT5 pathway.