By contrast, TGF-β expression increased in the experimental group compared with the NC group, especially in the diabetic nephropathy group (P < 0.01), but MG132 treatment led to a decrease in TGF-β expression (P < 0.05), and there was a significantly lower expression of TGF-β in the MH group compared with the ML group (P < 0.05) (Figures 3 and 4). This evidence concerns the gene TGFB1 and diabetic kidney disease.