The matrix component biglycan is proinflammatory and signals through Toll-like receptors 4 and 2 in macrophages
J. Clin. Invest. Liliana Schaefer, et al. 115:2223 doi:10.1172/JCI23755 [Go to this article.]

Figure 3
LPS-stimulated macrophages secrete IL-6 and IL-1β, both of which induce the expression of BGN, which in turn stimulates TNF-α and MIP-2 mRNA and protein expression in macrophages. (A and B) ELISA for IL-6 (A) and IL-1β (B) in culture media from Bgn^+/0 and Bgn^–/0 macrophages left unstimulated or stimulated with 0.5 ng/ml LPS for 1 hour. (C and D) RT-PCR of BGN mRNA (C) and Western blot of BGN core protein (D) secreted into culture media from Bgn^+/0 and Bgn^–/0 macrophages 2 hours after stimulation with either IL-6 or IL-1β (both 10 ng/ml), normalized to GAPDH or β-tubulin, respectively. (E) Northern blots of TNF-α and MIP-2 mRNA (normalized to α-tubulin) in Bgn^+/0 and Bgn^–/0 macrophages after 6 hours of incubation with BGN (4 μg/ml). (F and G) Dose-dependent enhancement of TNF-α (F) and MIP-2 (G) concentrations in media from Bgn^+/0 or Bgn^–/0 macrophages cultured for 24 hours in the absence or presence of BGN (1 or 10 μg/ml). (H) Time-dependent enhancement of TNF-α concentrations in media from Bgn^+/0 or Bgn^–/0 macrophages cultured for 6 and 24 hours in the absence or presence of BGN (10 μg/ml). (I and J) ELISA for TNF-α (I) and MIP-2 (J) in media from Bgn^+/0 or Bgn^–/0 macrophages cultured for 6 hours in the absence or presence of LPS (0.5 ng/ml). Data are given as means ± SD from 3–7 animals. *P < 0.05 for macrophages with versus without BGN or LPS, respectively.