Fig. 3

HBV promotes ITGBL1 expression by upregulating RUNX2. (A) RUNX2 protein level elevation after the induction of HBV expression in HepAD38 cells. (B) Huh7 cells seeded in 6-well plates were transfected with 1 µg of pHBV1.2 and treated with increasing concentrations of the RUNX2 inhibitor CADD522. Cells were harvested 48 h post-transfection. RUNX2 expression was elevated in HBV-expressing Huh7 cells, and as the concentration of CADD522 increased, RUNX2 expression was downregulated. The upregulation of ITGBL1 by HBV was also blocked by the RUNX2 inhibitor. (C) Huh7 cells seeded in 6-well plates were transfected with 1 µg of pHBV1.2 and treated with increasing concentrations of the RUNX2 inhibitor Vitamin D3. Cells were harvested 48 h post-transfection. RUNX2 expression was elevated in HBV-expressing Huh7 cells, and as the concentration of VitD3 increased, RUNX2 expression was downregulated. The upregulation of ITGBL1 by HBV was also blocked by the RUNX2 inhibitor. (D) Since no difference in ITGBL1 expression was observed between patients with positive and negative hepatitis B e antigen (HBeAg), the ITGBL1 promoter plasmid and HBs and HBx expression plasmids were co-transfected into HEK293T cells (96-well plate), respectively, and the transcriptional activity of the ITGBL1 promoter was detected by dual-luciferase reporter assays 48 h after co-transfection. Expression of HBx and HBsAg promoted the activity of the ITGBL1 promoter, while interference with RUNX2 blocked the upregulation of ITGBL1 promoter activity. The figure shows a representative image