Fig. 5

CRP promoted monocyte migration by inducing CXCL7 expression in adipocytes. a After 12 h of starvation, 3T3-L1 adipocytes were stimulated with different concentrations of exogenous CRP recombinant protein. The supernatants were collected 24 h later. CXCL7 production was determined by ELISA and it revealed that CRP dose-dependently increased CXCL7 production in 3T3-L1 adipocytes, with a peak CRP dose of 10 μg/mL. *P < 0.05 versus control. b, c CRP increased CXCL7 protein expression as assessed by western blotting. The values were normalized to β-tubulin expression as a control. *P < 0.05 versus control. d, e Transwell assays with primary human PBMCs plated on the upper cell culture inserts and culture medium alone (control), CRP-treated 3T3-L1 adipocytes plated in the lower chambers in the presence or absence of an anti-CXCL7 antibody at 2 or 4 μg/mL or an isotype-matched IgG control (IgG). Scale bar, 50 μm. *P < 0.05 compared with control (untreated), ^#P < 0.05 compared with CRP-treated (untreated). Data represent mean ± SEM (n = 6)