Galectin-3 Mediates Cardiac Remodeling Caused by Impaired Glucose and Lipid Metabolism Through Inhibiting Two Pathways of Activating Akt.

Pathological cardiac remodeling is a leading cause of mortality in diabetic patients. Given the glucose and lipid metabolism disorders (GLD) in diabetic patients, it is urgent to conduct a comprehensive study of the myocardial damage under GLD and find key mechanisms. Apolipoprotein E knockout (ApoE-/-) mice, low-density lipoprotein receptor heterozygote (Ldlr+/-) syrian golden hamsters or H9C2 cells were used to construct GLD models -. And GLD significantly promoted cardiomyocyte fibrosis, apoptosis and hypertrophy in vivo and in vitro, while inhibition of galectin-3 (Gal-3) could significantly reverse this process. Then, the signal transmission pathways were determined. It was found that GLD considerably inhibited the phosphorylation of Akt at Thr308 / Ser473, whereas the silencing of Gal-3 could reverse the inhibition of Akt activity through PI3K-AktThr308 and AMPK-mTOR2-AktSer473 pathways. Finally, the PI3K, mTOR, AMPK inhibitor and Akt activator were used to investigate the role of pathways in regulating cardiac remodeling. Phospho-AktThr308 could mediate myocardial fibrosis, while myocardial apoptosis and hypertrophy were regulated by both phospho-AktThr308 and phospho-AktSer473. In conclusion, Gal-3 was an important regulatory factor in GLD-induced cardiac remodeling, and Gal-3 could suppress the phosphorylation of Akt at different sites in mediating cardiomyocyte fibrosis, apoptosis and hypertrophy.