Fig. 4: TGR5 mediates TCDCA-stimulated lipolysis via regulating cAMP levels.

a P-HSL and t-HSL proteins in primary white adipocytes. b, d, g and i Glycerol release assays in primary white adipocytes. c, f and h The cAMP levels of primary white adipocytes. e The mRNA levels of TGR5 in primary white adipocytes. Studies for a were conducted using primary white adipocytes treated with control vehicle (-TCDCA) or TCDCA (+TCDCA) at the concentration as indicated for 4 h. b Were conducted using primary white adipocytes treated with control vehicle (-TCDCA) or 100 μM TCDCA (+TCDCA) for 2 h, followed by incubation with Krebs-Ringer buffer, with or without 10 µM FSK, with or without 100 μM TCDCA at 37 °C for 2 h. c, d were conducted using primary white adipocytes treated with or without 100 µM TCDCA in the presence or absence of 100 µM SQ22536 for 4 h; e–g were conducted using primary white adipocytes transfected with double-stranded siRNA targeting TGR5 for 72 h, followed by treating with control vehicle (-TCDCA) or 100 μM TCDCA (+TCDCA) for 4 h; h, i were conducted using primary white adipocytes treated with or without 30 µM INT777 in the presence of control vehicle or 100 µM SQ22536 for 2 h. For (a, c, d, f, h and i), n = 5. For (b), n = 7 (- TCDCA - FSK), 6 (+TCDCA - FSK), 6 (-TCDCA + FSK) and 5 (+TCDCA + FSK). For (e), n = 6 (-TCDCA – siTGR5), 6 (+TCDCA - siTGR5), 5 (- TCDCA + siTGR5) and 6 (+TCDCA + siTGR5). For (g), n = 6 (-TCDCA – siTGR5), 5 (+TCDCA - siTGR5), 5 (- TCDCA + siTGR5) and 6 (+TCDCA + siTGR5). Data are expressed as the mean ± SEM, with individual data points. Data were analyzed by ordinary one-way ANOVA with Dunnett’s multiple comparisons test (a), or two-way RM ANOVA with Geisser-Greenhouse’s correction (b, d, g, i) or ordinary two-way ANOVA with Tukey’s multiple comparisons test (c, e, f, and h). Source data are provided as a Source Data file.