17Beta-estradiol attenuates programmed cell death in cortical pericontusional zone following traumatic brain injury via upregulation of ERalpha and inhibition of caspase-3 activation

Pericontusional zone (PCZ) of traumatic cerebral contusion is a target of pharmacological intervention. It is well studied that 17beta-estradiol has a protective role in ischemic brain injury, but its role in brain protection of traumatic brain damage deserves further investigation, especially in pericontusional zone. Here we show that 17beta-estradiol enhances the protein expression and mRNA induction of estrogen alpha receptor (ERalpha) and prevents from programmed cell death in cortical pericontusional zone. ERalpha specific antagonist blocks this protective effect of 17beta-estradiol. Caspase-3 activation occurs in cortical pericontusional zone of the oil-treated injured rat brain and its activation is inhibited by 17beta-estradiol treatment. Additionally, ERalpha specific antagonist reverses this inhibition. Pan-caspase inhibitor also protect cortical pericontusional zone from programmed cell death. Our present study indicates 17beta-estradiol protects from programmed cell death in cortical pericontusional zone via enhancement of ERalpha and decrease of caspase-3 activation.

Research highlights▶ 17Beta-estradiol prevents the cortical pericontusional zone (PCZ) from programmed cell death. ▶ 17Beta-estradiol treatment enhances mRNA induction and protein expression of estrogen receptor alpha in PCZ. ▶ The protective role of 17beta-estradiol in PCZ is via estragon receptor alpha. ▶ 17Beta-estradiol treatment inhibits the activation of caspase-3 in PCZ. ▶ ERalpha specific antagonist reverses the inhibition of caspase-3 activation by 17beta-estradiol in PCZ.