Research
Hormonal
Interleukin-33 (IL-33) improves insulin resistance and reduces adiposity by promoting the polarization of macrophages toward the anti-inflammatory M2 phenotype and activating innate lymphoid type 2 cells (ILC2s).
Research suggests that IL-33, a naturally occurring cytokine, may help reduce fat and improve insulin sensitivity by shifting immune cells in fat to a protective state. This is currently a research finding in animals, not a standard human treatment.
ModerateSupportsMEDIUM confidence
Interleukin-33... induces the production of large amounts of anti-inflammatory cytokines by AT ILC2s and also the polarization of ATMs toward an M2 phenotype (133). This results in AT mass reduction and improves insulin resistance (133, 134).
Why this rating
Based on murine models and specific cytokine interventions; less generalizable than the core M1/M2 mechanism.
Source
The Macrophage Switch in Obesity Development
Ângela Castoldi et al. · Frontiers in Immunology · 2016
DOI 10.3389/fimmu.2015.00637
narrative_reviewCited 561×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- In obesity, the accumulation of classically activated (M1) macrophages in adipose tissue drives insulin resistance through the secretion of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and the activation of stress kinases (JNK, IKK, p38 MAPK) that inhibit insulin receptor signaling.Good
- M2 macrophages in lean adipose tissue maintain insulin sensitivity by secreting anti-inflammatory cytokines (IL-10, TGF-β) and utilizing oxidative metabolism, whereas obesity shifts this balance toward M1.Good
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