Insights into estrogen receptor alpha modulation by cholestenoic acids

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Oxysterols are cholesterol metabolites involved in physiological and pathological processes.
• Their promiscuity extends to multiple receptors, including Estrogen Receptor alpha (ERα), impacting diseases like ER-positive breast cancer, inflammation, and atherosclerosis.

Purpose of the Study:

• To investigate the transcriptional activity of cholestenoic acid analogs on ERα.
• To elucidate the molecular determinants governing oxysterol activity at ERα and Liver X Receptors (LXR).
• To establish structure-activity relationships for understanding oxysterol promiscuity.

Main Methods:

• Synthesis of cholestenoic acid analogs with modified side chains.
• Assessment of transcriptional activity on ERα.
• Molecular dynamics simulations to predict receptor activity and binding modes.
• Analysis of structure-activity relationships.

Main Results:

• 3β-hydroxy-5-cholestenoic acid acts as an agonist for ERα, similar to 26-hydroxycholesterol.
• Molecular dynamics simulations predicted ERα activity for various cholestenoic acid analogs.
• Some analogs demonstrated selective activation of either ERα or LXR based on side chain modifications.

Conclusions:

• Cholestenoic acid analogs can modulate ERα activity, contributing to the understanding of oxysterol promiscuity.
• Side chain modifications influence the selectivity of oxysterol analogs for ERα versus LXR.
• This research provides insights into the molecular basis of oxysterol interactions with nuclear receptors.