The environmental obesogen bisphenol A increases macrophage self-renewal

Area of Science:

• Immunology
• Endocrinology
• Toxicology

Background:

• Macrophage self-renewal is crucial for tissue homeostasis.
• The role of endocrine signals in regulating macrophage self-renewal remains unclear.
• Bisphenol A (BPA) is an endocrine disruptor with potential effects on immune cells.

Purpose of the Study:

• To investigate the effect of BPA on macrophage self-renewal.
• To explore the underlying molecular mechanisms involving extracellular signal-regulated kinase (ERK) and liver X receptor alpha (LXRα).
• To assess the implications of BPA-induced macrophage self-renewal on adipose tissue health.

Main Methods:

• In vitro studies on macrophage self-renewal.
• Analysis of ERK phosphorylation and LXRα expression.
• Pharmacological inhibition and activation of LXRα signaling.
• Assessment of macrophage populations in adipose tissue.

Main Results:

• BPA significantly increased macrophage self-renewal.
• This effect correlated with ERK phosphorylation and altered LXRα expression.
• LXRα inhibition promoted self-renewal, while activation impeded it.
• Self-renewing macrophages exhibited lower LXRα expression compared to quiescent ones.
• BPA accumulation in adipose tissue may promote self-renewal of resident macrophages.

Conclusions:

• BPA enhances macrophage self-renewal, partly through modulation of LXRα signaling.
• LXRα signaling appears to act as a protective mechanism against excessive macrophage proliferation.
• BPA-induced self-renewal of adipose tissue macrophages could compromise tissue health.