Interleukin-1β and lipopolysaccharide decrease soluble guanylyl cyclase in brain cells: NO-independent destabilization of protein and NO-dependent decrease of mRNA

Abstract

We previously showed that soluble guanylyl cyclase (sGC) is down-regulated in astroglial cells after exposure to LPS. Here, we show that this effect is not mediated by released IL-1β but that this cytokine is also able to decrease NO-dependent cGMP accumulation in a time- and concentration-dependent manner. The effect of IL-1β is receptor-mediated, mimicked by tumor necrosis factor-α and involves a decrease in sGC activity and protein. IL-1β and LPS decrease the half-life of the sGC β1 subunit by a NO-independent but transcription- and translation-dependent mechanism. Additionally, both agents induce a NO-dependent decrease of sGC subunit mRNA. Decreased sGC subunit protein and mRNA levels are also observed in adult rat brain after focal injection of IL-1β or LPS.