Docosahexaenoic acid attenuates macrophage-induced inflammation and improves insulin sensitivity in adipocytes-specific differential effects between LC n-3 PUFA

J Nutr Biochem. 2012 Sep;23(9):1192-200. doi: 10.1016/j.jnutbio.2011.06.014. Epub 2011 Dec 1.


Objective: Adipose tissue inflammation with immune cell recruitment plays a key role in obesity-induced insulin resistance (IR). Long-chain (LC) n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory potential; however, their individual effects on adipose IR are ill defined. We hypothesized that EPA and DHA may differentially affect macrophage-induced IR in adipocytes.

Methods: J774.2 macrophages pretreated with EPA or DHA (50 μM for 5 days) were stimulated with lipopolysaccharide (LPS, 100 ng/ml for 30 min-48 h). Cytokine secretion profiles and activation status of macrophages were assessed by enzyme-linked immunosorbent assay and flow cytometry. Pretreated macrophages were seeded onto transwell inserts and placed over 3T3-L1 adipocytes for 24-72 h; effects on adipocyte-macrophage cytokine cross-talk and insulin-stimulated ³H-glucose transport into adipocytes were monitored.

Results: DHA had more potent anti-inflammatory effects relative to EPA, with marked attenuation of LPS-induced nuclear factor (NF)κB activation and tumor necrosis factor (TNF)α secretion in macrophages. DHA specifically enhanced anti-inflammatory interleukin (IL)-10 secretion and reduced the expression of proinflammatory M1 (F4/80⁺/CD11⁺) macrophages. Co-culture of DHA-enriched macrophages with adipocytes attenuated IL-6 and TNFα secretion while enhancing IL-10 secretion. Conditioned media (CM) from DHA-enriched macrophages attenuated adipocyte NFκB activation. Adipocytes co-cultured with DHA-enriched macrophages maintained insulin sensitivity with enhanced insulin-stimulated ³H-glucose transport, GLUT4 translocation and preservation of insulin-receptor substrate-1 expression compared to co-culture with untreated macrophages. We confirmed that IL-10 expressed by DHA-enriched macrophages attenuates the CM-induced proinflammatory IR phenotype in adipocytes.

Conclusions: We demonstrate an attenuated proinflammatory phenotype of DHA-pretreated macrophages, which when co-cultured with adipocytes partially preserved insulin sensitivity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3-L1 Cells
  • Adipocytes, White / immunology
  • Adipocytes, White / metabolism*
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / metabolism*
  • Biological Transport
  • Cell Communication
  • Cell Line, Transformed
  • Coculture Techniques
  • Culture Media, Conditioned
  • Cytokines / metabolism
  • Docosahexaenoic Acids / metabolism*
  • Eicosapentaenoic Acid / metabolism
  • Glucose / metabolism
  • Glucose Transporter Type 4 / metabolism
  • Insulin / metabolism
  • Insulin Receptor Substrate Proteins / metabolism
  • Insulin Resistance*
  • Interleukin-10 / metabolism*
  • Macrophage Activation*
  • Macrophages / immunology*
  • Macrophages / metabolism
  • Mice
  • Protein Transport


  • Anti-Inflammatory Agents, Non-Steroidal
  • Culture Media, Conditioned
  • Cytokines
  • Glucose Transporter Type 4
  • IL10 protein, mouse
  • Insulin
  • Insulin Receptor Substrate Proteins
  • Irs1 protein, mouse
  • Slc2a4 protein, mouse
  • Interleukin-10
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • Glucose