Inhibition of matrix metalloproteinase-9 secretion by dimethyl sulfoxide and cyclic adenosine monophosphate in human monocytes

Figure 4 Activation of adenylyl cyclase inhibits lipopolysaccharide-induced matrix-metalloproteinase-9 and tumor necrosis factor α secretion. A: SDS-PAGE/immunoblot of cell supernatants. Lane 9 is a matrix-metalloproteinase-9 standard; B: Densitometry of Panel A. Each data bar is the average ± standard error for three independent densitometry measurements; and C: Tumor necrosis factor α (TNFα) levels were determined in cell supernatants by enzyme-linked immuno sorbent assay and each data bar is the average ± standard error for three independent measurements. THP-1 monocytes were treated with three forskolin (Fsk) concentrations that contained different percentages of dimethyl sulfoxide (DMSO), followed by lipopolysaccharide (1 μg/mL) for 72 h. Cells were collected, centrifuged at 500 g for 10 min and supernatant assessed for matrix-metalloproteinase-9 and TNFα. The red dashed lines in Panels B and C represent TNFα secretion induced by lipopolysaccharide (1 μg/mL) in the absence of DMSO or Fsk. Statistical differences (^aP < 0.05 or ^bP < 0.01) between DMSO and DMSO + Fsk are shown. LPS: Lipopolysaccharide; DMSO: Dimethyl sulfoxide; MMP-9: Matrix-metalloproteinase-9; TNFα: Tumor necrosis factor α; Fsk: Forskolin.