Amelioration of obesity-associated inflammation and insulin resistance in c57bl/6 mice via macrophage polarization by fish oil supplementation.
Enormous phenotypic plasticity makes macrophages the target cells in obesity-associated inflammatory diseases. Thus, nutritional components that polarize macrophages toward antiinflammatory phenotype can partially reverse inflammatory diseases like insulin resistance. In the present study, macrophage-polarizing and insulin-sensitizing properties of fish oil (FO) were evaluated in obese insulin-resistant c57bl/6 mice fed high-fat diet (HFD-IR) after oral supplementation with FO (4, 8 or 16mg/kg body weight) and compared to lean and HFD-IR mice. FO-supplemented HFD-IR mice exhibited reduced adiposity index, serum cholesterol and triglycerides and increased insulin sensitization and showed improved adipose tissue physiology under light and transmission electron microscopy. NF-κB/P65 expression showed a downward shift on FO supplementation. The surface marker of M1 macrophages (CD-86) and the TLR-4 expression reduced with the increased supplementation of FO. Expression of arginase 1, an important marker of M2 macrophages, increased in a dose-dependent manner in response to FO dosage, which was observed at protein level by the western blotting and at mRNA level by real-time PCR. The cytokine profile of adipose tissue macrophages showed a steep shift toward antiinflammatory ones (IL-4 and IL-10) from the inflammatory TNF-α, IFN-γ, IL-2 and IL-1β. Thus, macrophage polarization seems to be the plausible mechanism via which FO alleviates obesity-induced inflammation and insulin resistance.
Department of Biochemistry, Hamdard University, New Delhi, India.
Samina
S
Bashir
Department of Biochemistry, Hamdard University, New Delhi, India.
Yadhu
Y
Sharma
Department of Biochemistry, Hamdard University, New Delhi, India.
Asif
A
Elahi
Department of Biochemistry, Hamdard University, New Delhi, India. Electronic address: farahkhan3@gmail.com.
Farah
F
Khan
D052436:Adipose Tissue, White / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D050154:Adiposity; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use*; D019440:Anti-Obesity Agents / Q000008:administration & dosage / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D016764:Cell Polarity; D048429:Cell Size; D016207:Cytokines / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects; D019587:Dietary Supplements; D005395:Fish Oils / Q000008:administration & dosage / Q000627:therapeutic use*; D005786:Gene Expression Regulation; D006949:Hyperlipidemias / Q000209:etiology / Q000517:prevention & control; D056747:Immunomodulation; D007333:Insulin Resistance; D008099:Liver / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D009765:Obesity / Q000178:diet therapy* / Q000276:immunology / Q000378:metabolism / Q000473:pathology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D019440:Anti-Obesity Agents; D015415:Biomarkers; D016207:Cytokines; D005395:Fish Oils
Immunomodulation; Inflammation; Macrophage polarization; NF-κB/p65; Obesity