Caspase Inhibition Restores NEP Expression and Rescues Olfactory Deficit in Rats Caused by Prenatal Hypoxia.

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• Early-life olfactory system development is crucial for survival and behavior.
• Prenatal hypoxia impairs offspring olfaction, linked to reduced neprilysin (NEP) and increased caspase activity.
• Caspase inhibition previously restored NEP and improved memory in hypoxic rats.

Purpose of the Study:

• To investigate the effect of caspase inhibition on NEP mRNA, dendritic spines, and olfactory function in rats exposed to prenatal hypoxia.
• To determine if caspase inhibition can reverse hypoxia-induced olfactory deficits.

Main Methods:

• Prenatal hypoxia was induced in rats on embryonic day 14 (E14).
• A caspase inhibitor (Ac-DEVD-CHO) was administered intraventricularly on postnatal day 20 (P20).
• NEP mRNA expression, dendritic spine density, and olfactory function (food search, odor preference) were analyzed.

Main Results:

• Caspase inhibition restored NEP mRNA levels in the entorhinal cortex, parietal cortex, and hippocampus.
• The number of dendritic spines in these brain regions was normalized by caspase inhibition.
• Restored NEP and neuronal networking led to rescued olfactory function in treated rats.

Conclusions:

• Caspase activation due to prenatal hypoxia contributes to olfactory dysfunction in developing rats.
• Caspase inhibition offers a potential therapeutic strategy to restore olfactory deficits by upregulating NEP and improving neuronal connectivity.
• NEP's role in amyloid-beta degradation suggests implications for neurodegenerative diseases like Alzheimer's.