Inflammation has modulatory effects on the brain, particularly during development. These plastic changes can hold severe functional consequences. Perinatal hypoxia-ischemia (HI)-induced inflammation can result in cerebral palsy and cognitive impairment. In an attempt to reduce inflammation in the brain, we assessed the probiotic Bifidobacterium (B.) infantis as an HI intervention, using a rat model. Rat pups, developmentally equivalent to preterm infants, were exposed to chronic hypoxia from postnatal (PND) 3 –PND 10. Inflammation was assessed through hippocampal concentrations of the cytokine interleukin-6 (IL-6). Tissue was collected from pups on PND 10 and analyzed via enzyme-linked immunosorbent assay (ELISA). Results showed lower IL-6 concentrations in hypoxic groups , regardless of B. infantis administration. Qualitative observations suggested poor gut health in association with hypoxia and probiotic exposure. These preliminary findings support the chronic hypoxia exposure model of HI and suggest the association with IL-6 and HI events is less straightforward than expected. / October 2016

Hypoxia can result in brain injury. Hypoxic brain injury can also result in excess stress hormones and activated immune responses. In this study, we examined multiple spontaneous motor behaviors, concentrations of stress hormones, and gene expression of immune responses in rats after perinatal hypoxia. Hypoxic animals exhibited impaired spontaneous motor behaviors in several tests. Perinatal hypoxia also caused increased levels of stress hormones and altered expression of genes associated with adaptive and innate immunity at different time points after hypoxia exposure. Findings demonstrate stress hormones and immune responses are available to play an important role in perinatal brain injury and can impact delayed behavioral development.

Severe perinatal hypoxia represents a substantial brain injury in human newborns. This Diploma thesis is focused on long-term motor outcome of laboratory rat after moderate perinatal hypoxia. We described some behavioral test for detection motor development and presented the influence of perinatal hypoxia on central nervous system. We also discussed an effect of agonists and antagonists of adenosine A1 receptor in brain. The aim of an experimental part was an evaluation of long-term motor behavior in rats affected by perinatal hypoxia. To cause perinatal hypoxia we put pregnant female rats to a hypoxic (10% O2) normobaric room in 11th day of their gestation. The pregnant female rats stayed in hypoxic room until they gave a birth and 6 more days after birth with their litters. For classification of motor development we used battery of tests of motor coordination. These tests correspond to the level of development of the rat. Then a group of rats with perinatal hypoxia was treated by a single administration of an agonist of adenosine A1 receptor 2-chloro-N(6)- cyclopentyladenosin (CCPA) in postnatal day 14. The animals affected by perinatal hypoxia show motor deficits in 3 from 4 selected behavioral tests. Otherwise, this motor behavior was no longer detected in young adults. The rats affected by...

Der Transkriptionsfaktor hypoxia inducible factor-1 (HIF-1) trägt zur Expression von adaptiven Genen unter hypoxischen Bedingungen bei. Zusätzlich wurde vermutet, dass HIF-1 eine Rolle in der Regulation des späten neuronalen Zelltodes spielt. Suspensionszellen und adhärenten PC12-Zellen mit Nervenwachstumsfaktor (NGF) behandelt, wurden als ein experimentelles Modell für die Untersuchung der Beziehung zwischen Hypoxie induziertem Zelltod und Aktivität von HIF-1 herangezogen. Zelltod wurde durchflusszytometrisch mit einer Doppelfärbung (Annexin V und Propidium-Jodid) der Zellen und durch eine Analyse der allgemeinen Zelltodparameter wie LDH und die mitochondriale Dehydrogenase bestimmt. Parallel wurden Zellen mit einem Kontrollvektor und einem hypoxiesensitiven Vektor mit drei Hypoxie-bindenden-Elementen (HBE) transfiziert und die durch HIF-1 aktivierte Luciferase gemessen. Hypoxieexposition der NGF-behandelten PC12-Zellen resultierte in einer höheren Zelltodrate verglichen mit den unbehandelten Kontrollzellen. PC12 Zellen, zwei Tage mit NGF behandelt, zeigten eine bis zu 10-fach verminderte HIF-1-Aktivität. Diese Verminderung könnte zu dem erhöhten hypoxie-induzierten Zelltod durch verminderte Expression von HIF-1alpha-regulierten Genen, welche für die Anpassung an Hypoxie verantwortlich sind, beitragen. Die Verminderung der HIF-1 Aktivität und der Anstieg der Hypoxiesensitivität könnte darauf hinweisen, dass NGF als eine Art hierarchisch organisiertes Signalmolekül fungiert. / The transcription factor hypoxia-inducible factor-1 (HIF-1) strongly contributes to the expression of adaptive genes under hypoxic conditions. In addition, HIF-1 has been implicated in the regulation of delayed neuronal cell death. Suspension-grown and adherent PC12 cells treated with NGF were used as an experimental model for studying the relationship between hypoxia-induced cell death and activation of HIF-1. Cell damage was assessed by flow cytometry of double-stained (annexin V and propidiumiodide) cells, and by analysis of the overall death parameters LDH and mitochondrial dehydrogenase. In parallel, cells were transfected with a control and a three-hypoxia-responsive-elements (HRE)-containing vector and HIF-1-driven luciferase activity was determined. Exposure of NGF-treated PC12 cells to hypoxia resulted in a higher cell death rate when compared to untreated controls. PC12 cells exposed for 2 days to NGF exhibited a decrease of HIF-1 activity up to a factor of ten. This decrease may contribute to the enhanced hypoxia-induced cell death via reduced expression of HIF-1alpha-regulated genes resposible for adaptation to hypoxia, like those for glucose transport proteins and enzymes of the glycolytic chain. The decrease in HIF-1 activity and the increase in hypoxia sensitivity may suggest that NGF act as an hierachically organized signaling molecule.