The therapeutic effects of FGF21 on diabetic nephropathy are realized by augmenting autophagy via AMPK/mTOR signaling pathway

Abstract

Accumulating evidence demonstrates that FGF21 plays a preventive role in the development of diabetic nephropathy (DN). However, little is known about the therapeutical effects of FGF21 on DN and underlying mechanism. In this study, FGF21 significantly ameliorated blood glucose, HbAlc, insulin resistance, renal function and histopathological change in DN mice (BKS-Leprem2Cd479/Gpt), which develop abnormalities in renal morphology and function. Our results showed that administration of FGF21 upregulated the autophagy related genes LC3Ⅱ and BCL-1 mRNA and protein expression levels. D-glucose was used for high glucose (HG) model in mesangial cells. The results showed that treatment with FGF21 reduced the levels of ROS, AGEs and inflammatory cytokines and significantly downregulated the protein expression of PCNA. Meanwhile, FGF21 significantly enhanced the expression of LC3Ⅱ and BCL-1. Besides, Our studies showed that administration of FGF21 significantly upregulated the phosphorylation of AMPK and downregulated phosphorylation of mTOR. Meanwhile, the effects of FGF21 on autophagy were reversed by siRNA against β-klotho. In conclusion, The therapeutic effects of FGF21 on diabetic nephropathy are realized and FGF21 ameliorates mesangial cell glucotoxicity and abnormal proliferation in vitro by augmenting autophagy via AMPK/mTOR pathway. These results suggest that FGF21 can be a therapeutic target against DN.