The miR-9-5p/CXCL11 pathway is a key target of hydrogen sulfide-mediated inhibition of neuroinflammation in hypoxic ischemic brain injury

We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.

Resatorvid protects against hypoxic-ischemic brain damage in neonatal rats

Secondary brain damage caused by hyperactivation of autophagy and inflammatory responses in neurons plays an important role in hypoxic-ischemic brain damage(HIBD).Although previous studies have implicated Toll-like receptor 4(TLR4)and nuclear factor kappa-B(NF-κB)in the neuroinflammatory response elicited by brain injury,the role and mechanisms of the TLR4-mediated autophagy signaling pathway in neonatal HIBD are still unclear.We hypothesized that this pathway can regulate brain damage by modulating neuron autophagy and neuroinflammation in neonatal rats with HIBD.Hence,we established a neonatal HIBD rat model using the Rice-Vannucci method,and injected 0.75,1.5,or 3 mg/kg of the TLR4 inhibitor resatorvid(TAK-242)30 minutes after hypoxic ischemia.Our results indicate that administering TAK-242 to neonatal rats after HIBD could significantly reduce the infarct volume and the extent of cerebral edema,alleviate neuronal damage and neurobehavioral impairment,and decrease the expression levels of TLR4,phospho-NF-κB p65,Beclin-1,microtubule-associated protein l light chain 3,tumor necrosis factor-α,and interleukin-1βin the hippocampus.Thus,TAK-242 appears to exert a neuroprotective effect after HIBD by inhibiting activation of autophagy and the release of inflammatory cytokines via inhibition of the TLR4/NF-κB signaling pathway.This study was approved by the Laboratory Animal Ethics Committee of Affiliated Hospital of Yangzhou University,China(approval No.20180114-15)on January 14,2018.

Effects of ephedrine on expression of Nogo-A and synaptophysin in neonatal rats following hypoxic-ischemic brain damage

BACKGROUND： Central nervous system axons regenerate poorly following neonatal hypoxic-ischemic brain damage （HIBD）, partly due to inhibitors, such as Nogo-A. Very few studies have addressed the regulation of Nogo-A in neonatal rats following HIBD. However, numerous studies have shown that ephedrine accelerates neuronal remodeling and promotes recovery of neural function in neonatal rats following HIBD. OBJECTIVE： To investigate the effects of ephedrine on expression of Nogo-A and synaptophysin in brain tissues of neonatal rats following HIBD. DESIGN, TIME AND SETTING： A completely randomized, controlled study was performed at the Immunohistochemistry Laboratory of the Research Institute of Pediatrics, Children＇s Hospital of Chongqing Medical University from August 2008 to March 2009. MATERIALS： Ephedrine hydrochloride （Chifeng Pharmaceutical Group, China）, rabbit anti-Nogo-A polyclonal antibody （Abcam, UK）, and rabbit anti-synaptophysin polyclonal antibody （Lab Vision, USA） were used in this study. METHODS： A total of 96 healthy, neonatal, Sprague Dawley rats were randomly assigned to three groups （n = 32）： sham operation, HIBD, and ephedrine. The HIBD model was established by permanent occlusion of the left common carotid artery, followed by 2 hours of hypoxia （8% oxygen and 92% nitrogen）. In the sham operation group, the left common carotid artery was exposed, but was not ligated or subjected to hypoxia. Rats in the ephedrine group were intraperitoneally injected with ephedrine immediately following HIBD, with 1.5 mg/kg each time. Rats in the sham operation and HIBD groups were injected with an equal volume of saline. All neonatal rats were treated once daily for 7 days. MAIN OUTCOME MEASURES： Histopathological damage to the cortex and hippocampus was determined by hematoxylin-eosin staining. Expression of Nogo-A and synaptophysin was detected using immunohistochemical staining. RESULTS： Neuronal degeneration and edema were observed in the hypoxJc-Jschemic cortex and hippocampus by hematoxylin-eosin staining. Compared with the sham operation group, the levels of Nogo-A significantly increased in the HIBD group at various time points （P 〈 0.01）. Nogo-A expression was significantly reduced in the ephedrine group compared with the HIBD group （P 〈 0.01）. Synaptophysin expression was significantly decreased in the hypoxic-ischemJc cortex, compared with the sham operation group （P 〈 0.01）. Synaptophysin levels were significantly increased in the ephedrine group, compared with the HIBD group （P 〈 0.01）. CONCLUSION： Altered Nogo-A expression was associated with inversely altered synaptophysin expression. The use of ephedrine normalized expression levels of Nogo-A and synaptophysin following HIBD.

Altered protein markers related to neural plasticity and motor function following electro-acupuncture treatment in a rat model of ischemic-hypoxic brain injury

BACKGROUND：Previous studies have demonstrated that acupuncture treatment could ameliorate impaired motor function,and these positive effects might be due to neural plasticity.OBJECTIVE：Myelin basic protein（MBP）,microtubule-associated protein 2（MAP2）,growth-associated protein-43（GAP-43）,and synaptophysin（SYN） were selected as markers of neural remodeling,and expression of these markers was evaluated with regard to altered motor function following brain injury and acupuncture treatment.DESIGN,TIME AND SETTING：A completely randomized experiment was performed at the Central Laboratory of Peking University First Hospital from November 2006 to May 2007.MATERIALS：Twenty-four Sprague Dawley rat pups,aged 7 days,were selected for the present experiment.The left common carotid artery was ligated to establish a rat model of ischemic-hypoxic brain injury.METHODS：All animals were randomly divided into three groups：sham operation,model,and electro-acupuncture treatment,with 8 rats in each group.Rats in the model and electro-acupuncture treatment group underwent establishment of ischemic-hypoxic brain injury.Upon model established,rats underwent hypobaric oxygen intervention for 24 hours.Only the left common carotid artery was exposed in rats of the sham operation group,without model establishment or oxygen intervention.The rats in the electro-acupuncture treatment group were treated with electro-acupuncture.One acupuncture needle electrode was inserted into the subcutaneous layer at the Baihui and Dazhui acupoint.The stimulation condition of the electro-acupuncture simulator was set to an amplitude-modulated wave of 0-100% and alternative frequency of 100 cycles/second,as well as frequency-modulated wave of 2-100 Hz and an alternative frequency of 3 cycles/second.Maximal current through the two electrodes was limited to 3-5 mA.The stimulation lasted for 30 minutes per day for 2 weeks.Rats in the sham operation and model groups were not treated with electro-acupuncture,but only fixed to the table for the same time period.MAIN OUTCOME MEASURES：After 2 weeks stimulation,expression of MBP,MAP2,GAP-43,and SYN were detected in the brain by immunohistochemistry.Motor function was evaluated in the three groups.RESULTS：In the sham operation group,MBP was abundant in the myelinated nerve fibers.In the electro-acupuncture treatment group,however,the corpus callosum exhibited more MBP staining than the model group.MAP2 expression was increased in the model group,and increased further in the electro-acupuncture treatment group compared with the sham operation group.GAP-43 expression in the cerebral cortex was less in model group than in sham operation,but present in abundance in the electro-acupuncture treatment group.SYN expression in the cerebral cortex was less in the model and electro-acupuncture treatment group compared with the sham operation group.There was no significant difference in SYN expression and distribution between the model and electro-acupuncture treatment groups.Motor function of rats in the electro-acupuncture treatment group was significantly better than the model group（P 〈 0.05）,although function remained lower than the sham operation group（P 〈 0.05）.CONCLUSION：Two weeks of electro-acupuncture treatment improved motor function in rats,and protein markers related to neural plasticity also changed,which may be a mechanism for improved motor function in rats with ischemic-hypoxic brain injury.

Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cell transplantation improves hypoxic-ischemic brain injury

Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein. BrdU-positive cells at day 7 post-transplantation, as well as nestin- and neuron specific enolase-positive cells at day 14 were increased compared with those of the single neural stem cell transplantation group. In addition, the proportion of neuronal differentiation was enhanced. The genetically modified cell-transplanted rats exhibited enhanced performance in correctly crossing a Y-maze and climbing an angled slope compared with those of the single neural stem cell transplantation group. These results showed that human insulin-like growth factor 1-transfected neural stem cell transplantation promotes the recovery of the leaming, memory and motor functions in hypoxic-ischemic rats.

Diffusion tensor imaging of neural tract injury in a patient with hypoxic-ischemic brain injury

Hypoxic-ischemic brain injury （HI-BI） is one of the most common causes of severe neurological disability, Some studies have reported diffusion tensor imaging （DTI） findings of neonatal patients with HI-BI. However, very little is known about DTI in the adult brain. The present study reports on a 15-year-old male patient with HI-BI, who exhibited no specific focal lesions on conventional brain MRI at 5 weeks. However, neural tract injuries were revealed by DTI. Seven control subjects were also evaluated. The patient suffered from cardiac arrest due to ventricular fibrillation for a period of 10 15 minutes. At 4 weeks after onset of cardiac arrest, although he was conscious and alert, he exhibited mild quadriparesis and severe cognitive dysfunction. DTI was acquired at 5 weeks after HI-BI onset. Decreased fractional anisotropy or voxel number of neural tracts suggested partial injury of the corticospinal tract, fornix, and cingulum. Disruptions of the fornix and cingulum on DTI confirmed neural tract injury. DTI could serve as a useful tool for evaluating the state of neural tracts in patients with HI-BI.

Estrogen inhibits lipid peroxidation after hypoxic-ischemic brain damage in neonatal rats

Sprague-Dawley neonatal rats within 7 days after birth were used in this study. The left common carotid artery was occluded and rats were housed in an 8% O2 environment for 2 hours to establish a hypoxic-ischemic brain damage model. 17β-estradiol （1 × 10-5 M） was injected into the rat abdominal cavity after the model was successfully established. The left hemisphere was obtained at 12, 24, 48, 72 hours after operation. Results showed that malondialdehyde content in the left brain of neonatal rats gradually increased as modeling time prolonged, while malondialdehyde content of 17β-estrodial-treated rats significantly declined by 24 hours, reached lowest levels at 48 hours, and then peaked at 72 hours after injury. Nicotinamide-adenine dinucleotide phosphate histochemical staining showed the nitric oxide synthase-positive cells and fibers dyed blue/violet and were mainly distributed in the cortex, hippocampus and medial septal nuclei. The number of nitric oxide synthase-positive cells peaked at 48 hours and significantly decreased after 17β-estrodial treatment. Our experimental findings indicate that estrogen plays a protective role following hypoxic-ischemic brain damage by alleviating lipid peroxidation through reducing the expression of nitric oxide synthase and the content of malondialdehyde.

Flunarizine and lamotrigine prophylaxis effects on neuron-specific enolase, S-100, and brain-specific creatine kinase in a fetal rat model of hypoxic-ischemic brain damage

BACKGROUND： Calcium antagonists may act as neuroprotectants, diminishing the influx of calcium ions through voltage-sensitive calcium channels. When administered prophylactically, they display neuroprotective effects against hypoxic-ischemic brain damage in newborn rats. OBJECTIVE： To investigate the neuroprotective effects of flunarizine （FNZ）, lamotrigine （LTG） and the combination of both drugs, on hypoxic-ischemic brain damage in fetal rats. DESIGN AND SETTING： This randomized, complete block design was performed at the Department of Pediatrics, Shenzhen Fourth People＇s Hospital, Guangdong Medical College. MATERIALS： Forty pregnant Wistar rats, at gestational day 20, were selected for the experiment and were randomly divided into FNZ, LTG, FNZ ＋ LTG, and model groups, with 10 rats in each group. METHODS： Rats in the FNZ, LTG, and FNZ ＋ LTG groups received intragastric injections of FNZ （0.5 mg/kg/d）, LTG （10 mg/kg/d）, and FNZ （0.5 mg/kg/d） ＋ LTG （10 mg/kg/d）, respectively. Drugs were administered once a day for 3 days prior to induction of hypoxia-ischemia. Rats in the model group were not administered any drugs. Three hours after the final administration, eight pregnant rats from each group underwent model establishment hypoxia-ischemia brain damage to the fetal rats. Cesareans were performed at 6, 12, 24, and 48 hours later; and 5 fetal rats were removed from each mother and kept warm. Two fetuses without model establishment were removed by planned cesarean at the same time and served as controls. A total of 0.3 mL serum was collected from fetal rats at 6, 12, 24, and 48 hours, respectively, following birth. MAIN OUTCOME MEASURES： Serum protein concentrations of neuron-specific enolase and S-100 were measured by ELISA. Serum concentrations of brain-specific creatine kinase were measured using an electrogenerated chemiluminescence method. RESULTS： Serum concentrations of neuron-specific enolase, S-100, and brain-specific creatine kinase were significantly higher in the hypoxic-ischemic fetal rats, compared with the non-hypoxic-ischemic group. Serum concentrations of neuron-specific enolase, S-100, and brain-specific creatine kinase were significantly less in the FNZ, LTG, and FNZ ＋ LTG groups following ischemia, compared with the model group （P 〈 0.01）. However, these values were significantly greater in the FNZ and LTG groups, compared with the FNZ ＋ LTG group, following ischemia （P 〈 0.01）. CONCLUSION： Preventive antenatal use of oral FNZ and LTG has positive neuroprotective effects on intrauterine hypoxic-ischemic brain damage. The combined effect of these two drugs is superior.

Environmental enrichment promotes neural remodeling in newborn rats with hypoxic-ischemic brain damage

We evaluated the effect of hypoxic-ischemic brain damage and treatment with early environmental enrichment intervention on development of newborn rats, as evaluated by light and electron microscopy and morphometry. Early intervention with environmental enrichment intelligence training attenuated brain edema and neuronal injury, promoted neuronal repair, and increased neuronal plasticity in the frontal lobe cortex of the newborn rats with hypoxic-ischemic brain damage.

660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment

Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hy- poxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efficiencies are relatively low. Red or near-infrared light from 600-1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the treatment of hypoxic-ischemic brain damage. In this study, the migra- tion and colonization of cultured bone marrow mesenchymal stem cells on primary neurons after oxygen-glucose deprivation were detected using Transwell assay. The results showed that, after a 40-hour irradiation under red light-emitting diodes at 660 nm and 60 mW/cmz, an increasing number of green fluorescence-labeled bone marrow mesenchymal stem cells migrated towards hypoxic-ischemic damaged primary neurons. Meanwhile, neonatal rats with hypoxic-ischemic brain damage were given an intraperitoneal injection of 1 x 106 bone marrow mesenchymal stem cells, followed by irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2 for 7 successive days. Shuttle box test results showed that, after phototherapy and bone marrow mesenchymal stem cell transplantation, the active avoidance response rate of hypoxic-ischemic brain damage rats was significantly increased, which was higher than that after bone marrow mesenchymal stem cell transplantation alone. Experimental findings indicate that 660 nm red light emitting diode irradiation promotes cells, thereby enhancing the contribution ic-ischemic brain damage. the migration of bone marrow mesenchymal stem of cell transplantation in the treatment of hypox-

Hyperbaric oxygen treatment promotes neural stem cell proliferation in the subventricular zone of neonatal rats with hypoxic-ischemic brain damage

Hyperbaric oxygen therapy for the treatment of neonatal hypoxic-ischemic brain damage has been used clinically for many years, but its effectiveness remains controversial. In addition, the mechanism of this potential neuroprotective effect remains unclear. This study aimed to investigate the influence of hyperbaric oxygen on the proliferation of neural stem cells in the subventricular zone of neonatal Sprague-Dawley rats （7 days old） subjected to hypoxic-ischemic brain damage. Six hours after modeling, rats were treated with hyperbaric oxygen once daily for 7 days. Immunohistochemistry revealed that the number of 5-bromo-2＇-deoxyuridine positive and nestin positive cells in the subventricular zone of neonatal rats increased at day 3 after hypoxic-ischemic brain damage and peaked at day 5. After hyperbaric oxygen treatment, the number of 5-bromo-2＇- deoxyuddine positive and nestin positive cells began to increase at day 1, and was significantly higher than that in normal rats and model rats until day 21. Hematoxylin-eosin staining showed that hyperbaric oxygen treatment could attenuate pathological changes to brain tissue in neonatal rats, and reduce the number of degenerating and necrotic nerve cells. Our experimental findings indicate that hyperbaric oxygen treatment enhances the proliferation of neural stem cells in the subventricular zone of neonatal rats with hypoxic-ischemic brain damage, and has therapeutic potential for promoting neurological recovery following brain injury.

Negative regulation of miRNA-9 on oligodendrocyte lineage gene 1 during hypoxic-ischemic brain damage

Oligodendrocyte lineage gene 1 plays a key role in hypoxic-ischemic brain damage and myelin repair, miRNA-9 is involved in the occurrence of many related neurological disorders. Bioin- formatics analysis demonstrated that miRNA-9 complementarily, but incompletely, bound oligodendrocyte lineage gene 1, but whether miRNA-9 regulates oligodendrocyte lineage gene 1 remains poorly understood. Whole brain slices of 3-day-old Sprague-Dawley rats were cultured and divided into four groups： control group; oxygen-glucose deprivation group （treatment with 8% O2 ＋ 92% N2 and sugar-free medium for 60 minutes）; transfection control group （after oxygen and glucose deprivation for 60 minutes, transfected with control plasmid） and miRNA-9 transfection group （after oxygen and glucose deprivation for 60 minutes, transfected with miRNA-9 plasmid）. From the third day of transfection, and with increasing culture days, oligodendrocyte lineage gene 1 expression increased in each group, peaked at 14 days, and then decreased at 21 days. Real-time quantitative PCR results, however, demonstrated that oligoden- drocyte lineage gene 1 expression was lower in the miRNA-9 transfection group than that in the transfection control group at 1, 3, 7, 14, 21 and 28 days after transfection. Results suggested that miRNA-9 possibly negatively regulated oligodendrocyte lineage gene 1 in brain tissues during hypoxic-ischemic brain damage.

Vascular endothelial growth factor: an attractive target in the treatment of hypoxic/ischemic brain injury

Cerebral hypoxia or ischemia results in cell death and cerebral edema, as well as other cellular reactions such as angiogenesis and the reestablishment of functional microvasculature to promote recovery from brain injury. Vascular endothelial growth factor is expressed in the central nervous system after hypoxic/ischemic brain injury, and is involved in the process of brain repair via the regulation of angiogenesis, neurogenesis, neurite outgrowth, and cerebral edema, which all require vascular endothelial growth factor signaling. In this review, we focus on the role of the vascular endothelial growth factor signaling pathway in the response to hypoxic/ischemic brain injury, and discuss potential therapeutic interventions.

Interventional effect of laser acupoint radiation on the expression of Nissl body and brain-derived neurotrophic factor in newborn rat models with ischemic/hypoxic cerebral injury

BACKGROUND： Some researches report that He-Ne laser can activate function of erythrocytes and increase content of blood and oxygen via bio-stimulating effect; therefore, it suspects that laser radiation at Baihui and Dazhui can partially increase blood circulation for oxygen-supplying content of brain and improve functional status of neurons. OBJECTIVE： To verify the effects of laser radiation at Baihui and Dazhui on the expression of Nissl body of brain tissue neurons and brain-derived neurotrophic factor （BDNF） in newborn rats with ischemic/hypoxic cerebral injury. DESIGN： Randomized controlled animal study. SETTING： Department of Neurological Histochemistry, Xianning University. MATERIALS： Forty Wistar rats of 7 - 8 days old, weighing 15 - 20 g and of both genders, were selected from Wuhan Experimental Animal Center. All the rats were randomly divided into sham operation group （n =8）, model group （n =16） and radiation group （n = 16）. The experimental animals were disposed according to ethical criteria. BDNF kit was provided by Wuhan Boster Bioengineering Co., Ltd. METHODS： The experiment was carried out in the Department of Neurological Histochemistry, Xianning University from April 2005 to October 2006. Rats in the radiation group and model group were performed with ligation of left common carotid artery, recovered at room temperature for 1 - 6 days, maintained in self-made hypoxic cabin under normal pressure and injected mixture gas （0.05 volume fraction of 02 and 0.92 volume fraction of N2） for 2 hours. In addition, rats in the sham operation group were treated with separation of left common carotid artery but not ligation and hypoxia. Rats in the model group were not given any treatment; while, rats in the radiation group were exposed with He-Ne laser of 63.28 nm in the wave length at Baihui and Dazhui acupoints on the second day after ischemia-hypoxia. The radiation was given for 10 minutes per day and once a day. Ten days were regarded as a course and the rats were exposed for 2 courses in total. At 20 days after routine breeding, left hemisphere tissues of rats in the three groups were collected for staining of Nissl body and immunohistochemistry of BDNF. MAIN OUTCOME MEASURES： Nissl body staining in left hemisphere tissue and expression of immune positive cells of BDNF. RESULTS： All 40 rats were involved in the final analysis. （1） Nissl body staining： Neuronal cytoplasm of brain tissue was full of blue granule Nissl bodies in the sham operation group; while, Nissl body in neuronal cytoplasm in the model group was stained slightly and had a certain degree of degeneration; meanwhile, there were a lot of blank area in ischemic region. Nissl body in neuron cytoplasm was gradually recovered in the radiation group and relieved as compared with that in the model group. （2） Positive cells of BDNF： Number of immune positive cells of BDNF which were ligated in lateral cerebral hemisphere of rats in the model group was higher than that in the sham operation group （P 〈 0.05）; while, BDNF expression in the radiation group was increased as compared with that in the model group （P 〈 0.05）. CONCLUSION： After laser acupoint radiation, Nissl body is increased and BDNF expression is also increased. This suggests that laser acupoint radiation has neuroprotective effect on brain tissue after ischemia-hypoxia injury.

Exploring the mechanism of neuronal apoptosis and brain developmental damage in the hippocampus of hypoxicischemic neonatal rats based on BDNF/TrkB/CREB pathway

Objective:Based on the BDNF/TrkB/CREB pathway,to explore the mechanism of neuronal apoptosis and brain developmental injury in the hippocampus of hypoxic-ischemic neonatal rats.Methods:Wistar young rats were ligated on one side of the common carotid artery and placed in an 8%oxygen and 92%nitrogen hypoxia box for 2 h to prepare hypoxic-ischemic brain injury models.Healthy rats were used as the control group.Control group and model group were selected,with 10 rats in each group,and the learning and memory ability was tested by Y-maze;2,3,5-triphenyltetrazolium chloride(TTC)staining was used to detect brain tissue damage;Western blot was performed to determine the expression of brain-derived neurotrophic factor(BDNF),tyrosine protein kinase B(TrKB)and cAMP-response element binding protein(CREB)in hippocampal tissue.Another 15 mice in the control group and 60 mice in the model group were divided into negative control group(NC),BDNF overexpression group(LV-BDNF),TrkB overexpression group(LV-TrkB),and CREB overexpression group(LV-CREB),blank vector,BDNF,TrkB,CREB adenovirus overexpression vector was injected into the tail vein.Y-maze test for learning and memory ability;TTC staining method to detect brain tissue damage;neuronal apoptosis in the hippocampus were detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling;Western blot to detect the level of neuronal apoptosis in the hippocampus.Apoptosis-related protein B-cell lymphoma-2(Bcl-2),BCL2associated X protein(Bcl-2 Assaciated X,Bax)and nuclear factor kappaB(NFκB)expression.Results:The learning and memory ability of the young mice in the model group was significantly reduced,the brain infarct volume was significantly increased,the expressions of BDNF and TrkB proteins in the hippocampus were significantly increased,and the expression of CREB proteins was significantly decreased;After overexpression of BDNF and TrkB CREB,in the LVBDNF,LVTrkB,and LVCREB group,the learning and memory ability of young mice were significantly improved,the brain infarct volume were significantly reduced,the hippocampal neuronal apoptosis were significantly reduced,The protein expression of Bax and NFκB were significantly decreased and the protein expression of Bcl2 were significantly enhanced.Conclusion:The expression of BDNF/TrkB/CREB is abnormal in HIBI model young mice.Overexpression of BDNF/TrkB/CREB can improve the learning and memory ability of young mice,repair brain tissue damage,and inhibit neuronal apoptosis.Therefore,the mechanism of HIBI may be related to BDNF/TrkB/CREB pathways.

EFFECT OF MILD HYPOTHERMIA ON ACTIVITY NITRIC OXIDE SYNTHASE IN CORTICAL NEURONS AND GLYCEMIA LEVELS OF NEONATAL RATS WITH HYPOXIC ISCHEMIC BRAIN DAMAGE

Through investigating the effect of mild hypothermia on activity of nitric oxide snythase (NOS) in cortical neurons and glycemia levels of neonatal rats with hypoxic ischemic brain damage (HIBD). We studied the mechanism of protecting hypoxic ischemic neurons of mild hypothermia. We established neonatal rat HIBD models, used NOS immunohistochemistry and glycemia determination by micromethod. The number of cortical NOS positive neurons after hypoxic ischemia was significantly decreased as compared with controls. The glycemia levels was significantly increased than that controls. No significant difference was found in number of cortical NOS positive neurons and glycemia levels between 31℃ and 34℃ mild hypothemia. The results imply that hypothermia can decrease overproduction of NO through inhibiting the increase of the activity of NOS, and increase the glycemia levels, thus protect the hypoxic ischemic neurons.

Neuroprotective effects of autophagy inhibition on hippocampal glutamate receptor subunits after hypoxia-ischemia-induced brain damage in newborn rats

Autophagy has been suggested to participate in the pathology of hypoxic-ischemic brain damage（HIBD）.However,its regulatory role in HIBD remains unclear and was thus examined here using a rat model.To induce HIBD,the left common carotid artery was ligated in neonatal rats,and the rats were subjected to hypoxia for 2 hours.Some of these rats were intraperitoneally pretreated with the autophagy inhibitor 3-methyladenine（10 m M in 10 μL） or the autophagy stimulator rapamycin（1 g/kg） 1 hour before artery ligation.Our findings demonstrated that hypoxia-ischemia-induced hippocampal injury in neonatal rats was accompanied by increased expression levels of the autophagy-related proteins light chain 3 and Beclin-1 as well as of the AMPA receptor subunit GluR 1,but by reduced expression of GluR 2.Pretreatment with the autophagy inhibitor 3-methyladenine blocked hypoxia-ischemia-induced hippocampal injury,whereas pretreatment with the autophagy stimulator rapamycin significantly augmented hippocampal injury.Additionally,3-methyladenine pretreatment blocked the hypoxia-ischemia-induced upregulation of Glu R1 and downregulation of GluR2 in the hippocampus.By contrast,rapamycin further elevated hippocampal Glu R1 levels and exacerbated decreased GluR2 expression levels in neonates with HIBD.Our results indicate that autophagy inhibition favors the prevention of HIBD in neonatal rats,at least in part,through normalizing Glu R1 and GluR2 expression.

Brain metabolism in patients with vegetative state after post-resuscitated hypoxic-ischemic brain injury： statistical parametric mapping analysis of F-18 fluorodeoxyglucose positron emission tomography

Background Hypoxic-ischemic brain injury （HIBI） after cardiopulmonary resuscitation is one of the most devastating neurological conditions that causing the impaired consciousness. However, there were few studies investigated the changes of brain metabolism in patients with vegetative state （VS） after post-resuscitated HIBI. This study aimed to analyze the change of overall brain metabolism and elucidated the brain area correlated with the level of consciousness （LOC） in patients with VS after post-resuscitated HIBI. Methods We consecutively enrolled 17 patients with VS after HIBI, who experienced cardiopulmonary resuscitation. Overall brain metabolism was measured by F-18 fluorodeoxyglucose positron emission tomography （F-18 FDG PET） and we compared regional brain metabolic patterns from 17 patients with those from 15 normal controls using voxel-by-voxel based statistical parametric mapping analysis. Additionally, we correlated the LOC measured by the JFK-coma recovery scale-revised of each patient with brain metabolism by covariance analysis. Results Compared with normal controls, the patients with VS after post-resuscitated HIBI revealed significantly decreased brain metabolism in bilateral precuneus, bilateral posterior cingulate gyrus, bilateral middle frontal gyri, bilateral superior parietal gyri, bilateral middle occipital gyri, bilateral precentral gyri （PFEw correctecd 〈0.0001 ）, and increased brain metabolism in bilateral insula, bilateral cerebella, and the brainstem （PFEWcorrectecd 〈0.0001 ）. In covariance analysis, the LOC was significantly correlated with brain metabolism in bilateral fusiform and superior temporal gyri （P uncorrected 〈0.005）. Conclusions Our study demonstrated that the precuneus, the posterior cingulate area and the frontoparietal cortex, which is a component of neural correlate for consciousness, may be relevant structure for impaired consciousness in patient with VS after post-resuscitated HIBI. In post-resuscitated HIBI, measurement of brain metabolism using PET images may be helpful for investigating the brain function that cannot be obtained by morphological imaging and can be used to assess the brain area responsible for consciousness.

Time-dependent effect of combination therapy with erythropoietin and granulocyte colony-stimulating factor in a mouse model of hypoxic-ischemic brain injury

Erythropoietin （EPO） and granulocyte colony- stimulating factor （G-CSF） are likely to play broad roles in the brain. We investigated the effects of combination therapy with EPO and G-CSF in hypoxic- ischemic brain injury during the acute, subacute, and chronic phases. A total of 79 C57BL/6 mice with hypoxic-ischemic brain injury were randomly assigned acute （days 1-5）, subacute （days 11-15）and chronic （days 28-32） groups. All of them were treated with G-CSF （250 μg/kg） and EPO （5 000 U/kg） or saline daily for 5 consecutive days. Behavioral assessments and immunohistochemistry for angiogenesis, neuro- genesis, and astrogliosis were performed with an 8-week follow-up. Hypoxia-inducible factor-1 （HIF-1） was also measured by Western blot analysis. The results showed that the combination therapy with EPO and G-CSF in the acute phase significantly improved rotarod performance and forelimb-use symmetry compared to the other groups, while subacute EPO and G-CSF therapy exhibited a modest improvement compared with the chronic saline controls. The acute treatment significantly increased the density of CD31^＋（PECAM-1） and a-smooth muscle actin^＋ vessels in the frontal cortex and striatum, increased BrdU^＋/PSA- NCAM^＋ neurogenesis in the subventricular zone, and decreased astroglial density in the striatum. Furthermore, acute treatment significantly increased the HIF-1 expression in the cytosol and nucleus, whereas chronic treatment did not change the HIF-1 expression, consistent with the behavioral outcomes. These results indicate that the induction of HIF-1 expression by combination therapy with EPO and G-CSF synergistically enhances not only behavioral function but also neurogenesis and angiogenesis while decreasing the astroglial response in a time- dependent manner.

Semi-quantitative Assessment of Brain Maturation by Conventional Magnetic Resonance Imaging in Neonates with Clinically Mild Hypoxic-ischemic Encephalopathy

Background：Mild hypoxic-ischemic encephalopathy （HIE） injury is becoming the major type in neonatal brain diseases.The aim of this study was to assess brain maturation in mild HIE neonatal brains using total maturation score （TMS） based on conventional magnetic resonance imaging （MRI）.Methods：Totally,45 neonates with clinically mild HIE and 45 matched control neonates were enrolled.Gestated age,birth weight,age after birth and postmenstrual age at magnetic resonance （MR） scan were homogenous in the two groups.According to MR findings,mild HIE neonates were divided into three subgroups：Pattern Ⅰ,neonates with normal MR appearance; Pattern Ⅱ,preterm neonates with abnormal MR appearance; Pattern Ⅲ,full-term neonates with abnormal MR appearance.TMS and its parameters,progressive myelination （M）,cortical infolding （C）,involution of germinal matrix tissue （G）,and glial cell migration bands （B）,were employed to assess brain maturation and compare difference between HIE and control groups.Results：The mean of TMS was significantly lower in mild HIE group than it in the control group （mean ± standard deviation [SD] 11.62 ± 1.53 vs.12.36 ± 1.26,P 〈 0.001）.In four parameters of TMS scores,the M and C scores were significantly lower in mild HIE group.Of the three patterns of mild HIE,Pattern Ⅰ （10 cases） showed no significant difference of TMS compared with control neonates,while Pattern Ⅱ （22 cases）,Ⅲ （13 cases） all had significantly decreased TMS than control neonates （mean ± SD 10.56 ± 0.93 vs.11.48 ± 0.55,P 〈 0.05; 12.59 ± 1.28 vs.13.25 ± 1.29,P 〈 0.05）.It was M,C,and GM scores that significantly decreased in Pattern Ⅱ,while for Pattern Ⅲ,only C score significantly decreased.Conclusions：The TMS system,based on conventional MRI,is an effective method to detect delayed brain maturation in clinically mild HIE.The conventional MRI can reveal the different retardations in subtle structures and development processes among the different patterns of mild HIE.