bay-11-7082 and Stroke

Multi-protein complexes, termed "inflammasomes," are known to contribute to neuronal cell death and brain injury following ischemic stroke. Ischemic stroke increases the expression and activation of nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) Pyrin domain containing 1 and 3 (NLRP1 and NLRP3) inflammasome proteins and both interleukin (IL)-1β and IL-18 in neurons. In this study, we provide evidence that activation of either the NF-κB and MAPK signaling pathways was partly responsible for inducing the expression and activation of NLRP1 and NLRP3 inflammasome proteins and that these effects can be attenuated using pharmacological inhibitors of these two pathways in neurons and brain tissue under in vitro and in vivo ischemic conditions, respectively. Moreover, these findings provided supporting evidence that treatment with intravenous immunoglobulin (IVIg) preparation can reduce activation of the NF-κB and MAPK signaling pathways resulting in decreased expression and activation of NLRP1 and NLRP3 inflammasomes, as well as increasing expression of anti-apoptotic proteins, Bcl-2 and Bcl-xL, in primary cortical neurons and/or cerebral tissue under in vitro and in vivo ischemic conditions. In summary, these results provide compelling evidence that both the NF-κB and MAPK signaling pathways play a pivotal role in regulating the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons and brain tissue under ischemic conditions. In addition, treatment with IVIg preparation decreased the activation of the NF-κB and MAPK signaling pathways, and thus attenuated the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons under ischemic conditions. Hence, these findings suggest that therapeutic interventions that target inflammasome activation in neurons may provide new opportunities in the future treatment of ischemic stroke.

Topics: Adaptor Proteins, Signal Transducing; Animals; Anthracenes; Apoptosis Regulatory Proteins; Brain; Brain Ischemia; Butadienes; Extracellular Signal-Regulated MAP Kinases; Imidazoles; Inflammasomes; Mice; Neurons; NF-kappa B; Nitriles; NLR Family, Pyrin Domain-Containing 3 Protein; Pyridines; Signal Transduction; Stroke; Sulfones

Acute ischemic stroke is one of the most important factors leading to disability and death with the characterization of accumulated neuron death and injured supportive neurovascular structures. Raf-1 kinase inhibitory protein (RKIP) is a key molecule in cell response to survival or death stimuli. However, the role of RKIP in stroke is worthy to be further studied.. We used lentivirus mediated RKIP knockdown and overexpression to investigate the effect of RKIP on animal models of focal cerebral ischemia. Cell Counting Kit-8 assay, lactate dehydrogenase release analysis, and Annexin V-APC apoptosis assay were used to detect the effect RKIP on microglial cell apoptosis and survival. Transwell migration assay was carried out to evaluate the migration of microglia cells. The releases of inflammatory cytokines were determined by ELISA. The activation of NF-kappaB signaling pathway was determined by western blot.. Overexpression of RKIP reduced focal cerebral ischemia injury. RKIP knockdown and overexpression regulated survival, activation, and motility via the NF-κB pathway. NF-κB inhibitor BAY 11-7082 blocked the changes caused by RKIP down-regulation after oxygen-glucose deprivation (OGD). RKIP overexpression inhibited the upregulation of phosphorylation of NF-κB induced by OGD and cerebral ischemia.. The present study showed that RKIP protects against ischemic stroke through inhibition of microglial excessive activation, inhibits its motility, and promotes neuronal survival partly though IKKβ-IκBα-NF-κB signaling axis and indicate that RKIP is a new target for the treatment of ischemic stroke.

Topics: Animals; Apoptosis; Brain Ischemia; Cerebral Cortex; Gene Expression Regulation; I-kappa B Kinase; Interleukin-1beta; Male; Microglia; NF-kappa B; Nitric Oxide Synthase Type II; Nitriles; Phosphatidylethanolamine Binding Protein; Primary Cell Culture; Rats; Rats, Sprague-Dawley; RNA, Small Interfering; Signal Transduction; Stroke; Sulfones; Tumor Necrosis Factor-alpha