Fig. 5: The effect of Kyn is mediated by IL-6.

a Kyn (100 μg mL⁻¹) and TCZ (100 μg mL⁻¹) were added to stimulate 3T3-L1 derived adipocytes. Representative Oil Red staining images of the mature adipocytes. The experiments were performed independently three times. Scale bar, 100 µm. b After the treatment of Kyn (100 μg mL⁻¹) with or without TCZ (100 μg mL⁻¹), 100 nM insulin was added into the medium for 15 min before collecting the adipocytes. Western blot was conducted to detect p-ACC^Ser79/ACC, p-HSL^Ser660/HSL, p-AKT^Ser473/AKT in adipocytes (n = 3 independent experiments). c Body weight change of WT mice fed with 8-week NCD (n = 6) or HFD treated with PBS (n = 8) or Kyn (20 mg kg⁻¹) (n = 10) or TCZ (5 mg kg⁻¹) (n = 8) for another month, respectively. GTT (d) and ITT (e) of WT mice fed with 8-week NCD (n = 6) or HFD treated with PBS (n = 8) or Kyn (20 mg kg⁻¹, n = 9 for IGTT and n = 8 for ITT, respectively) or TCZ (5 mg kg⁻¹, n = 8) for another month. f Representative H&E staining images of eWAT originated from 8 weeks NCD and HFD fed mice following PBS, Kyn or TCZ treatment for one month (n = 6). Scale bar, 100 µm. g Western blot analysis of p-ACC^Ser79/ACC, p-HSL^Ser660/HSL, p-AKT^Ser473/AKT in eWAT from NCD, HFD, HFD+Kyn-treated mice and HFD+Kyn+TCZ-treated mice (n = 4). Statistical significance was assessed by one-way ANOVA (b, f and g) or two-way ANOVA followed with Bonferroni’s multiple comparisons test (c, d and e) and significant differences were indicated with p values. Source data are provided in the Source Data file.