Sepsis causes neuroinflammation and concomitant decrease of cerebral metabolism

<p>Abstract</p> <p>Background</p> <p>Septic encephalopathy is a severe brain dysfunction caused by systemic inflammation in the absence of direct brain infection. Changes in cerebral blood flow, release of inflammatory molecules and metabolic alterations contribute to neuronal dysfunction and cell death.</p> <p>Methods</p> <p>To investigate the relation of electrophysiological, metabolic and morphological changes caused by SE, we simultaneously assessed systemic circulation, regional cerebral blood flow and cortical electroencephalography in rats exposed to bacterial lipopolysaccharide. Additionally, cerebral glucose uptake, astro- and microglial activation as well as changes of inflammatory gene transcription were examined by small animal PET using [18F]FDG, immunohistochemistry, and real time PCR.</p> <p>Results</p> <p>While the systemic hemodynamic did not change significantly, regional cerebral blood flow was decreased in the cortex paralleled by a decrease of alpha activity of the electroencephalography. Cerebral glucose uptake was reduced in all analyzed neocortical areas, but preserved in the caudate nucleus, the hippocampus and the thalamus. Sepsis enhanced the transcription of several pro- and anti-inflammatory cytokines and chemokines including tumor necrosis factor alpha, interleukin-1 beta, transforming growth factor beta, and monocot chemoattractant protein 1 in the cerebrum. Regional analysis of different brain regions revealed an increase in ED1-positive microglia in the cortex, while total and neuronal cell counts decreased in the cortex and the hippocampus.</p> <p>Conclusion</p> <p>Together, the present study highlights the complexity of sepsis induced early impairment of neuronal metabolism and activity. Since our model uses techniques that determine parameters relevant to the clinical setting, it might be a useful tool to develop brain specific therapeutic strategies for human septic encephalopathy.</p

Reduced Bcl-x expression correlates with enhanced caspase-3 activation in NF-κB2- and Bcl-3-deficient mice after 11 weeks of PrP infection

<p><b>Copyright information:</b></p><p>Taken from "Alteration of NF-κB activity leads to mitochondrial apoptosis after infection with pathological prion protein"</p><p></p><p>Cellular Microbiology 2007;9(9):2202-2217.</p><p>Published online 15 Jun 2007</p><p>PMCID:PMC2048569.</p><p>© 2007 The Authors; Journal compilation © 2007 Blackwell Publishing Ltd</p> A. Bcl-x expression (black arrows), active cleaved caspase-9 and caspase-3 were determined by immunohistological staining. , , and C57Bl/6 mice were inoculated with RML6 and three animals per groups were sacrificed at 11 weeks p.i. Brain sections of three animals were analysed for each mouse line. Representative areas of the entorhinal cortex are shown. Magnification ×20. B and C. For quantification of positive cells, three sections of three different mouse brains for each strain were chosen. The graphic represents the amount of positive cells in the brain of the deficient mice compared with the C57Bl/6 mice in percentage of control. SEM was shown as bars. For detailed information on quantification see