ACTIVATED PROTEIN C PREVENTS GLUTAMATE- AND THROMBIN-INDUCED ACTIVATION OF NUCLEAR FACTOR-kappa B IN CULTURED HIPPOCAMPAL NEURONS

作者：Gorbacheva L; Pinelis V; Ishiwata S; Strukova S; Reiser G^*

来源：Neuroscience, 2010, 165(4): 1138-1146.

DOI：10.1016/j.neuroscience.2009.11.027

• excitotoxicity
• neurons
• activated protein C
• thrombin
• nuclear factor kappa B
• protease-activated receptor

Brain injury is associated with neuroinflammation, neurodegeneration, and also blood coagulation with thrombin formation and generation of activated protein C (APC). We have previously shown that APC, a serine protease of hemostasis, at very low concentrations has protective effects in rat hippocampal and cortical neurons at glutamate-induced excitotoxicity through protease-activated receptor-1 (PAR-1) or endothelial receptor of protein C (EPCR)/PAR-1. The transcription factor nuclear factor kappa B (NF-kappa B) takes part in regulating neuronal survival in several pathological conditions. To elucidate the impact of NF-kappa B in APC-mediated cell survival, we investigated nuclear translocation of NF-kappa B p65 at glutamate- or thrombin-induced toxicity in hippocampal neurons. We used immunoassay and immunostaining with confocal microscopy with anti-NF-kappa Bp65 antibody. We show that APC at concentrations as low as 1-2 nM inhibits translocation of NF-kappa B p65 into the nucleus of cultured rat hippocampal neurons, induced by 100 mu M glutamate or 50 nM thrombin (but not 10 nM). The blocking effect of APC on NF-kappa B p65 translocation was observed at 1 and 4 h after treatment of neurons with glutamate, when the NF-kappa Bp 65 level in the nucleus was significantly above the basal level. Then we investigated whether the binding of APC to EPCR/PAR-1 is required to control NF-kappa B activation. Antibodies blocking PARA (ATAP2) or EPCR (P-20) abolished the APC-induced decrease of nuclear level of NF-kappa B p65 at glutamate-induced toxicity, whereas control antibodies to PARA (S-19) and EPCR (IgG) exerted no effect. Thus, we suggest that the activation of NF-kappa B in rat hippocampal neurons mediates the glutamate- and thrombin-activated cell death program, which is reduced by exposure of cells to APC. APC induces the reduction of the nuclear level of NF-kappa B p65 in hippocampal neurons at glutamate-induced excitotoxicity via binding to EPCR and subsequent PARA activation and signaling.

• 出版日期2010-2-17