Glyburide inhibits IL-1β release from human monocytes without affecting the processing. Cell lysates (cyt) and supernatants (sup) from untreated human activated monocytes (U) or cells exposed to Glyburide (G; 100 μmol/L) were analyzed using Western blotting and probed with an anti–IL-1β specific antibody ([A] after LPS and ATP stimulation and [B] after long-term LPS stimulation). Reduced amounts of the 17-kD mature form of IL-1β are recovered in the supernatants of treated cells in the absence of a detectable difference in the intracellular profiles. In (C), the absence of effect of glyburide on the secretion of IL-6 is shown. In (D), supernatants from human activated monocytes either untreated (U) or treated with 100 μmol/L glyburide (G) or 100 μmol/L AcYVAD-CHO or both were analyzed using Western blotting. Whereas AcYVAD treatment leads to extracellular accumulation of proIL-1β and blocks its processing to the mature form, the treatment with glyburide clearly impairs the recovery of the precursor both in the absence and in the presence of ICE inhibitors.