Fig. 6: Mechanistic link between dual STAT1–mTOR signaling and lactate-induced M1 polarization in macrophages.

Detection of lactate (A) and glucose (B) levels in cell supernatants after treating RAW264.7 macrophages with different concentrations of F-MuLV for 24 h; n = 3. C, D qPCR analysis of the mRNA expression levels of IL-1β, iNOS, TNF-α, CD206, IL-10, and TGF-β in RAW264.7 macrophages treated with different concentrations of F-MuLV for 24 h. E, F Western blotting and quantitative analysis of the protein expression levels of STAT1, pSTAT1, mTOR, and pmTOR in macrophages treated with different concentration of F-MuLV for 24 h. G, H Western blotting and quantitative analysis of the protein expression levels of STAT1, pSTAT1, mTOR, and pmTOR in macrophages treated with 15% F-MuLV combined with the STAT1 inhibitor Fludarabine (20 μM) or the mTOR inhibitor Rapamycin (100 nM) for 24 h. I–K qPCR analysis measured iNOS, IL-10, and TGF-β mRNA expression in RAW264.7 macrophages treated with 15% F-MuLV and the indicated inhibitors for 6 h (I). Lactate (J) and glucose (K) levels in the corresponding supernatants are shown. L–N qPCR analysis evaluated iNOS and IL-10 mRNA expression in RAW264.7 macrophages treated with 20 mM Nala with or without 20 mM Oxamate for 12 h (L). Lactate (M) and glucose (N) levels in the corresponding cell supernatants are shown. O Conditioned medium (CM) from RAW264.7 macrophages treated with 20 mM Nala with or without 20 mM Oxamate for 12 h was assessed for its effect on the growth of HEL cells after 24 and 48 h of incubation. n = 3. The data are presented as the means ± SDs. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.