IL-1β promotes adipogenesis by directly targeting adipocyte precursors

Area of Science:

• Metabolic research
• Adipose tissue biology
• Inflammation and immunity

Background:

• Postprandial surges of Interleukin-1 beta (IL-1β) are prominent in white adipose tissue (WAT), but their functional impact remains unclear.
• Understanding the role of IL-1β in WAT energy storage is crucial for metabolic health insights.

Purpose of the Study:

• To investigate the specific role of IL-1β in regulating WAT energy storage and adipogenesis.
• To elucidate the cellular and molecular mechanisms by which IL-1β influences WAT remodeling.

Main Methods:

• Utilized genetically modified mice with specific deletions of the IL-1 receptor 1 (IL1R1).
• Performed in vitro studies using murine and human adipose-derived stem cells to assess adipogenesis.
• Analyzed the expression of adipogenic transcription factors (C/EBPδ and C/EBPβ) and their enrichment near target genes.

Main Results:

• Ubiquitous IL1R1 deficiency, but not adipocyte-specific deletion, reduced body weight, WAT mass, and adipocyte formation in mice.
• IL-1β significantly promoted adipogenesis in early-stage adipose-derived stem cells, upregulating C/EBPδ and C/EBPβ.
• The pro-adipogenic effect of IL-1β was potentiated by acute exposure and inhibited by chronic exposure.

Conclusions:

• Transient postprandial IL-1β surges physiologically promote WAT remodeling via adipogenesis.
• Chronically elevated IL-1β levels, as seen in obesity, may blunt this WAT-adaptive function, contributing to metabolic dysfunction.