Interleukin 1 beta (IL-1 beta) action in porcine thyroid cells involves the ceramide signalling pathway

Interleukin 1 beta (IL-1 beta) is often associated with thyroidal autoimmun e diseases. This cytokine has been largely described to trigger an importan t biological signalling pathway: the sphingomyelin/ceramide pathway. In thi s report we show that IL-1 beta induces ceramide formation and sphingomyeli n degradation in porcine thyroid cells via the activation of a neutral sphi ngomyelinase. Among the potential targets of IL-1 beta and ceramides action , we have investigated the role of an atypical protein kinase C (PKC), the PKC zeta. We show that both IL-1 beta and ceramides lead to an increase of PKC zeta activity. All these results suggest an important role for ceramide s and IL-1 beta in regulation of thyroid function, leading to cell survival or to apoptosis. (C) 2001 Academic Press.