Fig. 4.

SIK2 is downregulated by TNF-α in adipocytes. SIK2 mRNA expression in human adipocytes differentiated in vitro, treated with (a) increasing concentrations of TNF-α for 24 h and (b) TNF-α 50 ng/ml (black bars) or vehicle (white bars) for indicated time points (n = 3 independent experiments performed in duplicate). 18S rRNA was used as reference gene. (c) SIK2 protein levels in 3T3-L1 adipocytes treated with TNF-α 10 ng/ml (grey bars) or 50 ng/ml (black bars), or vehicle (white bars) for indicated time points (n = 3 independent experiments). (d) Representative blots with mean values for relative protein levels below. β-Actin and heat shock protein 90 (HSP90) were used as loading controls. Statistical significance determined by two-way ANOVA with Tukey’s (a, c) or Sidak’s (b) multiple comparisons post hoc tests. **p < 0.01, ***p < 0.001, and ^† p < 0.05, ^†† p < 0.01 TNF-α 10 ng/ml vs 50 ng/ml