Mu-opioid receptor-mediated phosphorylation of I kappa B kinase in human neuroblastoma SH-SY5Y cells

Opioid receptors are involved in regulating neuronal survival. Here we demonstrate that activation of the mu-opioid receptor in human neuroblastoma SH-SY5Y cells led to the phosphorylations Of I kappa B kinase (IKK) and p65, denoting the stimulation of the nuclear factor-kappa B (NF kappa B) transcription factor. This response was mediated through pertussis toxin-sensitive G proteins. The mu-opioid-induced IKK phosphorylation required extracellular signal-regulated protein kinase, phosphatidylinositol 3-kinase and c-Src. Moreover, c-Jun N-terminal kinase and calmodulin-dependent kinase 11 also participated in the IKK activation, despite the lack of involvement of phospholipase C beta and protein kinase C. These data suggest that the mu-opioid receptor is capable of simulating NF kappa B signaling via the phosphorylation of IKK and p65 in human neuroblastoma SH-SY5Y cells. Copyright (C) 2005 S. Karger AG, Basel.