Fig. 3
H2S production in mechanical load-stimulated periodontal ligament stem cells (PDLSCs) and the influence on macrophage polarization. a Schematic illustration. b Concentration of H2S in the supernatant of PDLSCs was upregulated after mechanical loading and downregulated by additional HA treatment with loaded conditioned medium. N = 3, *P < 0.05 versus control, #P < 0.05 versus force. c Relative mRNA expression of M1/M2-related genes. The mRNA expressions of M1 markers TNF-α and IL-1β of THP-1-derived macrophages were upregulated in FS group and downregulated in FS + HA group compared with the FS group, although the expression of TNF-α was still upregulated compared with the CS group. The mRNA expression of arginase-1 shows no change, and the expression of DECTIN was upregulated in the FS + HA group. N = 3, ***P < 0.001 versus CS. ###P < 0.001 versus FS. CS: control supernatant; FS: force-treated conditioned medium. FS + HA: force-treated conditioned medium with CBS inhibitor HA. d Western blot of iNOS, TNF-α and arginase-1. iNOS and TNF-α expressions of THP-1-induced macrophages were upregulated after incubated with the supernatant of force-treated PDLSCs and decreased after incubated with the supernatant of force-treated PDLSCs with HA application. Meanwhile, no changes were observed in arginase-1 expression. Beta-actin served as the internal control for equal loading. Data represent three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 versus CS. #P < 0.05, ###P < 0.001 versus FS