Immunofluorescence (IF) and Western blot were employed to analyze MMT progression (F4/80<sup>+</sup>/α-SMA<sup>+</sup> double-positive cells) and TGF-β1-Smad3/7 pathway activity.<h4>Results</h4>DAPA significantly reduced blood glucose levels, mitigated weight loss, and effectively inhibited type 2 diabetes-induced increase in Scr (43.78 ± 3.84 <i>vs.</i> 33.93 ± 6.77 μmol/L, <i>P</i> < 0.05) and UACR (89.17 ± 16.33 <i>vs.</i> 52.51 ± 10.51 mg/g, <i>P</i> < 0.05) in DKD mice. The gene discussed is SMAD3; the disease is type 2 diabetes mellitus.