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22. European Stroke Conference 536 © 2013 S. Karger AG, Basel Scientific Programme 469 Experimental studies Restoration of hypoxia-induced dysfunctional blood-brain barrier with brain-derived neuro-trophic factor C. Rodemer1, M.G. Hennerici2, S. Meairs3 UMM, Mannheim, GERMANY1, UMM, Mannheim, GERMANY2, UMM, Mannheim, GERMA-NY3 Background: Brain-derived neurotrophic factor (BDNF) is a neuronal survival factor found pre-dominantly in brain tissue. BDNF influences cell survival, triggers stem cell migration and induces synaptic plasticity. Here we studied effects of BDNF on hypoxic endothelial cells with and without co-cultured C6 astrocytes. Furthermore we examined effects of BDNF added during and after hy-poxia. Methods: Microvascular mouse brain endothelial cells (bEND.3) were placed for 20h in a hypoxia chamber (Billups-Rothenberg) with a 95%N2/5%CO2 atmosphere in OptiMEM (Invitrogen) with-out fetal calf serum and glucose. For co-culturing C6 astrocytes were used. Cells were incubated with or without additional BDNF (Biozol, 100ng/ml). Either BDNF was applied during 20h of hy-poxia or for 4h after the hypoxic period of 20h. As a blood-brain-barrier (BBB) functional marker Lucifer yellow (LY) flow through was determined. NO in cell lysates was also examined (BioCat). Results: LY flow through was reduced after hypoxia (wt:1.88cm/min+/-0.4;hypoxia:1,25+/-0.28). If BDNF was administered during hypoxia, values increased to normal (hypoxia+BDNF:1.64+/-0.24). Interestingly, BDNF administered for 4h after hypoxia could not rescue values (ctrl:1.27+/-0.19; hypoxia:0.91+/-0.18; hypoxia+BDNF:0.98+/-0.2).When we analyzed bEND.3 cells grown with C6 astrocytes, hypoxia effects were reduced (ctrl:0.96 +/- 0.16; hypoxia:0.89+/-0.04;hypoxia+BDNF: 0.96+/-0.09). Additional BDNF did not reduce hypoxia-increased amounts of NO. Conclusion: BDNF can restore the rate of flow through to normal levels only if administered during hypoxia. A period of 4h after hypoxia with BDNF could not significantly restore flow. BDNF may have an important role during hypoxia for BBB dysfunction. Interestingly, hypoxic effects could be partly reduced by co-cultured C6 astrocytes presumably by releasing important growth factors to the medium. NO levels were increased in hypoxic cells but could not be restored by exogenous BDNF. 468 Experimental studies The angiotensin II type 2 receptor -1332 A/G gene polymorphism (rs1403543) is associated with stroke in males patients with carotid atherosclerosis A. Kolaković1, M Živković2, I Konćar3, I Jovanović4, T Djurić5, A Stanković6 The Institute of Nuclear Sciences “Vinca” Laboratory for Radiobiology and Molecular Genet-ics, Belgrade, SERBIA1, The Institute of Nuclear Sciences “Vinca” Laboratory for Radiobiology and Molecular Genetics, Belgrade, SERBIA2, Institute for Cardiovascular Diseases, Clinical Center of Serbia, Belgrade, SERBIA3, The Institute of Nuclear Sciences “Vinca” Laboratory for Radiobiol-ogy and Molecular Genetics, Belgrade, SERBIA4, The Institute of Nuclear Sciences “Vinca” Labo-ratory for Radiobiology and Molecular Genetics, Belgrade, SERBIA5, The Institute of Nuclear Sci-ences “Vinca” Laboratory for Radiobiology and Molecular Genetics, Belgrade, SERBIA65 Background: The renin-angiotensin (RAS) system is an important player in pathogenesis of cardio-vascular disease and responsiveness for various types of medications.The major cardiovascular ac-tions of angiotensin II have been reported to be mediated by the AT1R and AT2R receptors.Carotid atherosclerosis (CA) is a leading cause of stroke and accounts for the majority of brain infarction. Progresive stenosis of the carotid artery is resulting in reduction of blood flow and subsequent re-duction in oxygen and glucose delivery essential for proper brain function.The genetic involvement of RAS in stroke remains unclear.A large number of genetic investigations have been considered the association between gene variants of RAS with increased risk for stroke, but there is a diversity in the results obtained.The present study aimed to examine whether functional -1332A/G gene poly-morphism is associated with stroke.The -1332A/G is located in intron 1 of gene and was proposed to inflence receptor expression.Methods: The study group consisted of 298 male and 212 female pa-tients with CA consecutively admitted for carotid endarterectomy.Genotyping was done by PCR and restriction digestion with EcoRI enzyme.Results: The genotype frequencies are analyzed separately in females and males, since gene is located on X chromosome.We detected significant overrepresen-tation of -1332G/G genotype in male patients group with stroke compared to male group without stroke (crude OR 2.03 95%CI 1.19-3.48,p<0.05).After adjusment for factors that significantly influ-enced susceptibility to CA and those which are significantly different between patients group with and without stroke (age, hypertension, smoking status, D-dimer, ApoAI, TG, WBC) the estimated OR for stroke was elevated and remain significant (OR 2.66, 95%CI 1.05-6.76,p=0.04).We did not found in females group significant difference according to genotypes.Conclusion: We concluded that -1332GG male carriers had increased risk for stroke in CA.


Karger_ESC London_2013
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