Connective tissue growth factor reacts as an IL-6/STAT3-regulated hepatic negative acute phase protein

Figure 3 Soluble gp80 receptor enhances the inhibitory effect of interleukin-6 on hepatocellular CYR61/CTGF/NOV 2/connective tissue growth factor expression in primary human hepatocytes. A: Western blottings of CYR61/CTGF/NOV (CCN) 2/Connective tissue growth factor (CTGF) and α1-AT of primary human hepatocytes cultured under serum-free conditions for 24 h and stimulated with rh interleukin (rhIL)-6 (35 μg/L), soluble gp80 receptor (sgp80, 1 mg/L) and soluble gp130 receptor (sgp130, 2 mg/L) or a complex of both. Cells were harvested after 24 h. β-actin served as loading control. Blots were quantified relative to β-actin using the Lumi Imager System. Representative blots are shown. ^aP < 0.005, ^bP < 0.0001 vs untreated or IL-6 treated control; B: Primary human hepatocytes were cultured and stimulated as described in (A). Cells were harvested after 48 h. β-actin served as loading control. Blots were quantified as described in (A). Representative blots are shown. ^aP < 0.005, ^bP < 0.0001 vs untreated or IL-6 treated control; C, D: Ultrasensitive C-reactive Protein as determined using a particle enhanced ultra sensitive assay on the Siemens BN2 nephelometer in supernatants from primary human hepatocytes cultures harvested after 24 h (C) and 48 h (D). The baseline indicates the lower detection limit of the assay at 0.15 mg/L.