Ethanol-induced decrease of developmental PKC isoform expression in the embryonic chick brain

Area of Science:

• Neuroscience
• Developmental Biology
• Pharmacology

Background:

• Prenatal ethanol exposure is a leading cause of birth defects, collectively known as fetal alcohol syndrome (FAS).
• Protein kinase C (PKC) plays a critical role in cell cycle regulation and cellular growth.
• Understanding ethanol's impact on PKC expression is vital for elucidating FAS mechanisms.

Purpose of the Study:

• To investigate the effects of ethanol on the expression of various protein kinase C (PKC) isoforms in the developing chick brain.
• To determine which PKC isoforms are developmentally regulated in the embryonic chick brain.
• To correlate ethanol-induced growth deficits with changes in PKC isoform expression.

Main Methods:

• Chick embryos were exposed to varying doses of ethanol.
• Head and brain weights were measured at embryonic days 5, 7, and 10.
• Western blot analysis using isoform-specific antibodies was performed to quantify PKC-alpha, -beta, -gamma, -delta, -epsilon, -iota, -lambda, -mu, and -zeta expression.

Main Results:

• Ethanol exposure led to a dose-dependent decrease in chick head weight by day 5 and brain weight by days 7 and 10.
• Only PKC-alpha, -gamma, -epsilon, and -iota isoforms were expressed in the developing chick brain before day 10.
• Ethanol significantly decreased the expression of PKC-alpha (days 5, 7, 10), PKC-gamma (days 7, 10), and PKC-epsilon (day 7), while PKC-iota expression remained unaffected.

Conclusions:

• Specific PKC isoforms (alpha, gamma, epsilon) are developmentally regulated in the embryonic chick brain.
• Ethanol exposure during development inhibits the expression of these developmentally regulated PKC isoforms.
• These findings suggest a potential mechanism by which prenatal ethanol exposure disrupts embryonic brain growth and development.