A Novel Role for Brain Natriuretic Peptide: Inhibition of IL-1 Secretion via Downregulation of NF-kB/Erk 1/2 and NALP3/ASC/Caspase-1 Activation in Human THP-1 Monocyte

Figure 3

BNP is involved in the priming mechanism controlling IL-1β production by inhibiting NF-kB and ERK 1/2 activation in THP-1 cells. (a) THP-1 cells were incubated with 10 μM BAY 11-7082 or U0-126 for 1 h and then treated with 10 μg/mL LPS/5 mM ATP for 48 h. The supernatants were collected and IL-1β release was measured by ELISA. (b, c, d) THP-1 cells were treated with 10⁻⁸M BNP in absence or presence of 10 μg/mL LPS/5 mM ATP for 30 min (b, c) or 48 h (b, c, d). Cell lysates were immunoblotted for P-IkB-α (b), P-ERK 1/2 (c), or pro-IL-1β (d). (e, f) THP-1 cells were incubated with 10 μM BAY 11-7082 (e) or U0-126 (f) for 1 h and then treated with 10 μg/mL LPS/5 mM ATP for 48 h. Cell lysates were immunoblotted for pro-IL-1β. The blots were stripped of the bound Ab and reprobed with mouse anti--actin, to confirm equal loading. Western blots are representative of three separate experiments. All histograms indicate means ± SD of three separate experiments each one tested in triplicate. and versus untreated cells and < 0.05, < 0.01, and < 0.001 versus LPS/ATP treated cells.