Chronic high fat diet induces cardiac hypertrophy and fibrosis in mice.

Background: Obesity can cause pathological changes in organs. We determined the effects of chronic high fat diet (HFD) and intermittent fasting, a paradigm providing organ protection, on mouse heart.

Methods: Seven-week old CD1 male mice were randomly assigned to control, HFD and intermittent fasting groups. Control mice had free access to regular diet (RD). RD was provided every other day to mice in the intermittent fasting group. Mice in HFD group had free access to HFD. Their left ventricles were harvested 11 months after they had been on these diet regimens.

Results: HFD increased cardiomyocyte cross-section area and fibrosis. HFD decreased active caspase 3, an apoptosis marker, and the ratio of microtubule-associated protein 1A/1B-light chain 3 (LC3) II/LC3I, an autophagy marker. HFD increased the phospho-glycogen synthase kinase-3β (GSK-3β) at Ser9, a sign of GSK-3β inhibition. Nuclear GATA binding protein 4 and yes-associated protein, two GSK-3β targeting transcription factors that can induce hypertrophy-related gene expression, were increased in HFD-fed mice. Mice on intermittent fasting did not have these changes except for the increased active caspase 3 and decreased ratio of LC3II/LC3I.

Conclusions: These results suggest that chronic HFD induces myocardial hypertrophy and fibrosis, which may be mediated by GSK-3β inhibition.