TGFB1 and diabetic neuropathy: In a hyperglycemic state, AGEs accumulate in pericytes and increase the autocrine secretion of VEGF and TGF-β, leading to the enhanced production of fibronectin and type IV collagen, suggesting that microvascular basement membrane thickening in diabetic neuropathy is caused by the accumulation of AGEs in pericytes under hyperglycemic conditions via VEGF and TGF-β signaling by autocrine secretion by pericytes (Figure 6) [36,37].