Figure 6.
Effect of mouse or human hemopexin (mHx or hHx) on hemin or hemoglobin (Hb) synergy with lipopolysaccharide (LPS) or Escherichia coli on bone marrow–derived macrophages (BMDMs) or human whole blood. BMDMs from C57BL/6 mice were washed 3 times with serum-free medium and then cultured overnight with 1 ng/mL of LPS in the absence (●) or presence (▲) of 300 μg/mL mHx and indicated concentrations of hemin (A) or Hb (B ). Concentrations of tumor necrosis factor (TNF) in the supernatants were determined by enzyme-linked immunosorbent assay. Fresh human whole blood was diluted 1:4 in serum-free medium and cultured for 1 h and then were coincubated overnight with 2.5 ng/mL LPS or 105 cfu/mL E. coli in the absence or presence of mHx (300 μg/mL) (C ), or 105 cfu/mL of E. coli with or without hHx (400 μg/mL) (D ). The results denote the mean ± the standard error and are representative of more than 4 independent experiments. *P <.05, **P <.01, ***P <.001, compared between samples treated with and without Hx.