Fig. 6

VSIG4 promoted SPP1 expression through enhancing the histone H3 lysine 18 lactylation and promoting the transcription activity of STAT3. (A) Co-culture of mATC with BMDMs isolated from VSIG4-KO and WT mice to examine the lactate concentration. (B) Isolation of TAMs from mATC-derived tumors in VSIG4-KO (n = 3) and WT mice (n = 3) on day 32 to examine the lactate concentration. Data are presented as mean ± S.E.M. (C-D) Co-culture of mATC with BMDMs isolated from VSIG4-KO and WT mice to examine the expressions of histone H3 lysine 18 lactylation (H3K18la). (E) Genome browser track analysis using dataset GSE192358 showed the H3K18la lactylation levels in the binding region of Spp1 with or without the lactate treatment, where the left area of the dotted line represented the binding region of H3K18la on the Spp1 promotor. The mRNA (F) and protein (G-H) level of Spp1 in BMDM with or without the lactate treatment (n = 3). (I-J) The expression of Stat1, pStat1, Stat3, pStat3, and pStat6 in BMDMs after VSIG4 knockout (n = 3). (K) The JASPAR database predicted the presence of STAT3 binding sites in the SPP1 promoter region. The mRNA (L) and protein (M-N) level of Spp1 in BMDMs after STAT3 inhibitor Stattic treatment (n = 3). (O) The transcriptional activity of STAT3 on SPP1 was determined by dual luciferase reporter gene assay (n = 3). Data are presented as mean ± S.D. *P < 0.05, **P < 0.01, ***P < 0.001