Effects of BAY 41-2272, an activator of nitric oxide-independent site of soluble guanylate cyclase, on human NADPH oxidase system from THP-1 cells

We investigated the effects of the 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b] pyridin-3-yl]-pyrimidin-4-ylamine (BAY 41-2272) on the NADPH oxidase activity, gp91phox gene expression, cyclic guanosine-3′,5′-monophosphate (cGMP) and cyclic adenosine-3′,5′-monophosphate (cAMP) levels in the human myelomonocytic THP-1 cell line. THP-1 cells treated with BAY 41-2272 (0.3–10 μM) for 48 h significantly increased the superoxide anion (O2•−) release. This increase was not affected when cells were pre-treated with the specific cGMP-phosphodiesterase inhibitor zaprinast, the soluble guanylate cyclase inhibitor 1H-[1,2,4] oxidiazolo[4,3-α] quinoxalin-1-one (ODQ), the adenylate cyclase inhibitor 9-(tetrahydro-2-furanyl) adenine (SQ 22,536) or the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME). In addition, BAY 41-2272 (3 and 10 μM; 48 h) was able to increase gp91phox gene expression on THP-1 cells. The pre-treatment with zaprinast, 3-isobutyl-l-methyl-xanthine (IBMX; 0.5 mM), ODQ, SQ 22,536 or l-NAME caused no additional effect on the expression of gp91phox evoked by BAY 41-2272. Treatment of THP-1 cells with BAY 41-2272 caused a significant increase in cGMP and cAMP levels. Our findings show that BAY 41-2272 caused a significant increase on the O2•− release and gp91phox gene expression by THP-1 cells, and an elevation of intracellular cGMP and cAMP levels. However, we could not detect a clear correlation between both O2•− release and gp91phox gene expression with activation of cGMP and cAMP signaling pathways.