Estradiol Activates PI3K/Akt/GSK3 Pathway Under Chronic Neurodegenerative Conditions Triggered by Perinatal Asphyxia

Area of Science:

• Neuroscience
• Endocrinology
• Developmental Biology

Background:

• Perinatal asphyxia (PA) is a major cause of neonatal mortality and long-term neurological deficits.
• Previous research indicated neurodegenerative markers increase in the hippocampus after PA.
• A late 17β-estradiol treatment showed promise in reverting PA-induced brain alterations.

Purpose of the Study:

• To elucidate the underlying mechanism of estradiol's beneficial effects in reversing chronic neurodegeneration caused by PA.
• To investigate the role of estrogen receptors and downstream signaling pathways in estradiol's neuroprotective action.

Main Methods:

• Adult male rats exposed to PA were treated with 17β-estradiol or vehicle.
• Protein levels of estrogen receptor alpha (ERα) and insulin-like growth factor receptor (IGF-1R) were assessed.
• Activation of the PI3K/Akt/GSK3β/β-catenin pathway was analyzed.
• The ratio of anti-apoptotic (Bcl-2) to pro-apoptotic (Bax) proteins was determined.

Main Results:

• Estradiol treatment increased ERα and IGF-1R protein levels in the hippocampus of PA-exposed rats.
• A significant activation of the PI3K/Akt/GSK3β/β-catenin signaling pathway was observed.
• The Bcl-2/Bax ratio, indicative of reduced apoptosis, was elevated in the estradiol-treated group.

Conclusions:

• Estradiol's neuroprotective effects in late-stage PA treatment are mediated by the ERα and IGF-1R interaction.
• This interaction activates downstream signaling pathways crucial for neuronal survival.
• The findings suggest a potential therapeutic strategy for PA-induced neurodegeneration.