AICAR ameliorates high-fat diet-associated pathophysiology in mouse and ex vivo models, independent of adiponectin

AICAR may promote metabolic health and protect against obesity-induced systemic diseases in an adiponectin-independent manner. Furthermore, AICAR reduced inflammation in human adipose tissue explants, suggesting by proof-of-principle that the drug may reduce obesity-induced complications in humans.

Six-week-old male C57BL/6J wild-type and Adipoq -/- mice were fed a standard-fat diet (10% fat) or an HFD (60% fat) for 12 weeks and given vehicle or AICAR (500 μg/g) three times/week from weeks 4-12. Diet-induced pathophysiology was examined in mice after 11 weeks by IPGTT and after 12 weeks by flow cytometry and western blotting. Human adipose tissue biopsies from obese (BMI 35-50 kg/m2) individuals were incubated with vehicle or AICAR (1 mmol/l) for 6 h at 37°C, after which inflammation was characterised by ELISA (TNF-α) and flow cytometry.

AICAR attenuated adipose inflammation in mice fed an HFD, promoting an M1-to-M2 macrophage phenotype switch, while reducing infiltration of CD8+ T cells. AICAR treatment of mice fed an HFD partially restored glucose tolerance and attenuated hepatic steatosis and kidney disease, as evidenced by reduced albuminuria (p < 0.05), urinary H2O2 (p < 0.05) and renal superoxide levels (p < 0.01) in both wild-type and Adipoq -/- mice. AICAR-mediated protection occurred independently of adiponectin, as similar protection was observed in wild-type and Adipoq -/- mice. In addition, AICAR promoted an M1-to-M2 macrophage phenotype switch and reduced TNF-α production in tissue explants from obese human patients. Conclusions/interpretation: AICAR may promote metabolic health and protect against obesity-induced systemic diseases in an adiponectin-independent manner. Furthermore, AICAR reduced inflammation in human adipose tissue explants, suggesting by proof-of-principle that the drug may reduce obesity-induced complications in humans.

ClinicalTrials.gov NCT02322073.