E2F1 and diabetic kidney disease: To further confirm that E2F1 is directly involved in metformin-alleviated fibrosis, DNA damage, and cellular senescence in DKD, we stimulated mRTECs with high glucose in vitro and found that the indexes related to E2F1, fibrosis, DNA damage, and cellular senescence increased significantly, but decreased after transfection with E2F1 siRNA.