The Study Of Hippocampus Inflammation Damage And DNA Methylation Changes After Ischemia And Hypoxia

Mammalian hippocampus is an important part of the central nervous system, and plays an crucial role in the process of learning, memory and other physical processes, but it is most sensitive and most serious injury when exposure to ischemia and hypoxia. Hypoxic-ischemic brain injury(hypoxic-ischemic brain damage, HIBD) because of its high incidence, high death rate, high morbidity, so it is usually result in serious consequences, so that the quality of life of patients is greatly affected, and also caused great harm to the family and society. Therefore,This study aims to establish a hypoxic-ischemic brain slice model to investigate the mouse hippocampus damage caused by HIBD and DNA methylations on mouse hippocampus after hypoxic-ischemic brain damage.Objective: To investigate the(1) effects on inflammatory injury after hypoxic-ischemic brain injury in mice hippocampus;(2) To explore the DNA methylation levels on mouse hippocampus after hypoxic-ischemic brain damage.Methods:(1) Healthy adult C57 BL / 6J mouse hippocampal slices were used to establish in vitro HIBD model, divided into normal control group(using normal culture medium hippocampal slices), hypoxia-ischemia experimental group(using glucose-free medium and anoxia tank filled with 95% N2,5% CO2 culture hippocampal slices). After the model established it is tested with 2, 3, 5-triphenyl tetrazolium chloride( TTC) staining. After TTC staining the normal control group shows red, the hypoxia-ischemia experimental group shows pale, so the model is successfully established. The normal control group and(2)the hypoxia-ischemia experimental group hippocampal slices were visualized by immunohistochemical to detect the expression of c-fos, COX2, 5-mc, DNMT3 a, MBD2, and western blotting to detect the expression of NF-κB、c-fos、COX2、DNMT1、DNMT3a、MBD2, then discuss the changes of inflammatory injury and the levels of DNA methylation.Results:(1) The impact of hypoxic-ischemic brain damage on mouse hippocampus inflammatory damage: in immunohistochemistry experiments, hypoxic-ischemic experimental group inflammatory injury cells of in hippocampal slices was significantly more than the control group(P < 0.01); Western blot test results is consistent with the results ofimmunohistochemistry experiments;(2) The affects on mouse DNA methylation levels after hypoxic-ischemic brain damage in the hippocampus: immunohistochemical staining showed that the hypoxic-ischemic experimental group hippocampus DNA methylation enzymes positive cells expression were significantly more than the control group(P < 0.01), the experimental group DNA methylation level was higher than the control group, Western blot test results is consistent with the results ofimmunohistochemistry experiments, but DNMT1 expression has no difference between the control group and the experimental group(P > 0.05).Conclusion:(1) Established brain slices in vitro model of ischemia and hypoxia.(2) hypoxic-ischemic can trigger hippocampal tissue inflammation damage.(3) ischemia and hypoxia increased DNA methylation levels, suggesting that DNA methylation may be involved in the process of hypoxic-ischemic tissue injury, the mechanism might be HIBD affect DNA metabolism induces elevated levels of DNA methylation, DNA methylation of genes associated with the expression of oxidative stress, trigger inflammation, damage to the hippocampus.