Fig. 4.

TPPU suppresses inflammation by enhancing HIF-1α expression. a, b, Expression levels of HIF-1α in HUVECs and cocultured cells across control group, LPS group and LPS + TPPU treatment group. a Representative IF image and quantification analysis of HIF-1α in HUVECs and cocultured HUVECs and PDLSCs. Scale bar = 100 µm. b Western blot and quantification for HIF-1α across different groups. Full-length blots/gels were presented in Additional file 3. c Western blot demonstrating the knockdown of HIF-1α in HUVECs. Full-length blots/gels were presented in Additional file 3. d-g, Knockdown of HIF-1α in HUVECs, examining the levels of cytokines and EMCN in HUVECs and cocultured HUVECs and PDLSCs treated with TPPU under inflammatory conditions. d, e RT‒qPCR and ELISA analyses showing the expression levels of IL-6, IL-1β, and TNF-α in HUVECs and cocultured HUVECs and PDLSCs. f, g, RT‒qPCR, Western blot and quantification for EMCN in HUVECs and cocultured cells across different groups, Full-length blots/gels were presented in Additional file 3. * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001