FN1 and glomerulosclerosis: But the typical pathological characteristics of DN can also be characterized by excessive proliferation of ECM and diffuse glomerular basement thickening of mesangial cells (MCs), which can eventually lead to glomerular sclerosis and renal interstitial fibrosis when exposed to high glucose [7, 8], because MCs can secrete various cytokines, such as transforming growth factor β1 (TGF-β1), collagen (COL), and fibronectin (FN) [9].