Effects of Estradiol on Autophagy and Nrf-2/ARE Signals after Cerebral Ischemia.

BACKGROUND/AIMS: Estradiol (EST) reduces the risk of stroke and decreases the incidence and progression of the disease because of its neuroprotective roles in inhibiting cell death that occurs in response to a variety of neuronal stimuli such as inflammation and oxidative stress. In this study, we determined the role played by autophagy and Nrf2-ARE signal pathways in the hippocampus regions in modulating cerebral ischemia under different EST conditions.

METHODS: Western blot analysis and ELISA were used to determine the protein expression of autophagy and Nrf2-ARE pathways; and the levels of pro-inflammatory cytokines (PICs) and a key marker of oxidative stress.

RESULTS: Lacking of EST amplifies autophagy and attenuates Nrf2-ARE pathway in the hippocampus CA1 region. Blocking autophagy alleviates neurological deficits following cerebral ischemia with lacking of EST levels and the effects of autophagy are associated with PIC and oxidative stress.

CONCLUSIONS: EST influences the protein expression of autophagy and Nrf2-ARE signaling in the brain, which is linked to the pathophysiological processes of PICs and oxidative stress. Moreover, inhibition of autophagy plays a beneficial role in modulating neurological deficits after cerebral ischemia observed under conditions of a lower level of EST.