Telmisartan Reduced Cerebral Edema by Inhibiting NLRP_3 Inflammasome in Mice with Cold Brain Injury

The aim of this study was to investigate the possible beneficial role of telmisartan in cerebral edema after traumatic brain injury（TBI） and the potential mechanisms related to the nucleotide-binding oligomerization domain（NOD）-like receptor（NLR） pyrin domain-containing 3（NLRP3） inflammasome activation. TBI model was established by cold-induced brain injury. Male C57BL/6 mice were randomly assigned into 3, 6, 12, 24, 48 and 72 h survival groups to investigate cerebral edema development with time and received 0, 5, 10, 20 and 40 mg/kg telmisartan by oral gavage, 1 h prior to TBI to determine the efficient anti-edemic dose. The therapeutic window was identified by post-treating 30 min, 1 h, 2 h and 4 h after TBI. Blood-brain barrier（BBB） integrity, the neurological function and histological injury were assessed, at the same time, the m RNA and protein expression levels of NLRP3 inflammasome, IL-1β and IL-18 concentrations in peri-contused brain tissue were measured 24 h post TBI. The results showed that the traumatic cerebral edema occurred from 6 h, reached the peak at 24 h and recovered to the baseline 72 h after TBI. A single oral dose of 5, 10 and 20 mg/kg telmisartan could reduce cerebral edema. Post-treatment up to 2 h effectively limited the edema development. Furthermore, prophylactic administration of telmisartan markedly inhibited BBB impairment, NLRP3, apoptotic speck-containing protein（ASC） and Caspase-1 activation, as well as IL-1β and IL-18 maturation, subsequently improved the neurological outcomes. In conclusion, telmisartan can reduce traumatic cerebral edema by inhibiting the NLRP3 inflammasome-regulated IL-1β and IL-18 accumulation.

Ataxia,acute mountain sickness,and high altitude cerebral edema

Previous investigations suggest that ataxia is common and often one of the most reliable warning signs of high altitude cerebral edema(HACE). The aim of this study was to investigate the diagnostic role of ataxia in acute mountain sickness(AMS)and HACE among mountain rescuers on the quake areas,and in approaching the relation between AMS and HACE. After the earthquake on April 14,2010,approximately 24 080 lowland rescuers were rapidly transported from sea level or lowlands to the mountainous rescue sites at 3 750 ~ 4 568 m,and extremely hardly worked for an emergency treatment after arrival. Assessments of acute altitude illness on the quake areas were using the Lake Louise Scoring System. 73 % of the rescuers were found to be developed AMS. The incidence of high altitude pulmonary edema(HAPE)and HACE was 0.73 % and 0.26 %,respectively,on the second to third day at altitude. Ataxia sign was measured by simple tests of coordination including a modified Romberg test. The clinical features of 62 patients with HACE were analyzed. It was found that the most frequent,serious neurological symptoms and signs were altered mental status(50/62,80.6 %)and truncal ataxia(47/62,75.8 %). Mental status change was rated slightly higher than ataxia,but ataxia occurred earlier than mental status change and other symptoms. The earliest sign of ataxia was a vague unsteadiness of gait,which may be present alone in association with or without AMS. Advanced ataxia was correlated with the AMS scores,but mild ataxia did not correlate with AMS scores at altitudes of 3 750~4 568 m. Of them,14 patients were further examined by computerized tomographic scanning of the brain and cerebral magnetic resonance imagines were examined in another 15 cases. These imaging studies indicated that the presence of the cerebral edema was in 97 % of cases who were clinically diagnosed as HACE(28/29). Ataxia seems to be a reliable sign of advanced AMS or HACE,so does altered mental status.

Aquaporin-4 in the formation of cerebral edema following severe burns What role do arginine vasopressin levels play?

BACKGROUND： Aquaporin-4 （AQP-4）, which is able to rapidly transport water within the brain, is highly expressed in brain tissue. It also plays an important role in the formation of cerebral edema following brain injury. However, the role of AQP-4 in the formation of cerebral edema following severe bums remains unknown. OBJECTIVE： To study changes in AQP-4 protein and mRNA expression during formation of cerebral edema following severe burns, and to explore the correlation between AQP-4 protein and mRNA expression with plasma levels of arginine vasopressin （AVP）. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Research Center of Neuroscience, Chongqing Medical University from 2007 to 2008. MATERIALS： Biotin-labeled goat anti-rabbit antibody was provided by Beijing Zhongshan Biotechnology, China; in situ hybridization kit was provided by Wuhan Boster Biotechnology, China; rabbit anti-AQP-4 polyclonal antibody and horseradish peroxidase-labeled goat anti-rabbit IgG were provided by Chemicon, USA; AVP radioimmunoassay kit was provided by the Research Department of Neurobiology, the Second Military Medical University of Shanghai, China. METHODS： A total of 180 adult, healthy, Wistar rats were randomly assigned to control and burn groups with 30 rats in each group. The burn group was observed at five different time points： 2, 6, 12, 24, and 48 hours after burn. Hair on the mouse back was removed to expose skin on the back. After 1 day, skin with the hair removed was dipped into 100℃ water for 15 seconds to induce grade III bum injury that measures 30% of total bum surface area. MAIN OUTCOME MEASURES： Brain water content was measured using the dry-wet weight method. AQP-4 protein and mRNA expressions were detected using immunohistochemistry, in situ hybridization, Western blot, and reverse transcription-polymerase chain reaction; dynamic changes in plasma AVP were detected using radioimmunoassay. RESULTS： Brain water content gradually increased following severe burn injury. AQP-4 protein and mRNA expressions were upregulated in the supraoptic nucleus, suprachiasmatic nucleus, paraventricular nucleus, hippocampus, choroid plexus, and cerebral cortex. Plasma AVP levels increased following burn injury. AQP-4 protein and mRNA expressions positively correlated with brain water content and AVP levels during formation of cerebral edema （r= 0.870, 0.848, P 〈 0.01）. CONCLUSION： AQP-4 participated in the formation of cerebral edema following burn injury. Plasma AVP upregulated AQP-4 expression in brain tissue, thereby promoting formation of cerebral edema.

Exendin-4 inhibits high-altitude cerebral edema by protecting against neurobiological dysfunction

The anti-inflammatory and antioxidant effects of exendin-4（Ex-4） have been reported previously.However,whether（Ex-4） has anti-inflammatory and antioxidant effects on high-altitude cerebral edema（HACE） remains poorly understood.In this study,two rat models of HACE were established by placing rats in a hypoxic environment with a simulated altitude of either 6000-or 7000-m above sea level（MASL） for 72 hours.An altitude of 7000 MASL with 72-hours of hypoxia was found to be the optimized experimental paradigm for establishing HACE models.Then,in rats where a model of HACE was established by introducing them to a 7000 MASL environment with 72-hours of hypoxia treatment,2,10 and,100 μg of Ex-4 was intraperitoneally administrated.The open field test and tail suspension test were used to test animal behavior.Routine methods were used to detect change in inflammatory cells.Hematoxylin-eosin staining was performed to determine pathological changes to brain tissue.Wet/dry weight ratios were used to measure brain water content.Evans blue leakage was used to determine blood-brain barrier integrity.Enzyme-linked immunosorbent assay（ELISA） was performed to measure markers of inflammation and oxidative stress including superoxide dismutase,glutathione,and malonaldehyde values,as well as interleukin-6,tumor necrosis factor-alpha,cyclic adenosine monophosphate levels in the brain tissue.Western blot analysis was performed to determine the levels of occludin,ZO-1,SOCS-3,vascular endothelial growth factor,EPAC1,nuclear factor-kappa B,and aquaporin-4.Our results demonstrate that Ex-4 preconditioning decreased brain water content,inhibited inflammation and oxidative stress,alleviated brain tissue injury,maintain blood-brain barrier integrity,and effectively improved motor function in rat models of HACE.These findings suggest that Ex-4 exhibits therapeutic potential in the treatment of HACE.

Effect of Glycerol Fructose Combined with Mannitol on Patients with Cerebral Hemorrhage and Cerebral Edema

Objective:To observe the effect of glycerol fructose combined with mannitol in the treatment of patients with clinical intracerebral hemorrhage complicated by cerebral edema and increased intracranial pressure,and to evaluate the clinical application value of this treatment.Methods:Seventy patients with cerebral hemorrhage complicated by brain edema were randomly divided into observation and control groups.Both groups had exactly the same number of study participants.There were some differences in specific treatment methods.The specific process is as follows:The control group was treated with mannitol,while the observation group was treated with dual-purpose glycerol fructose.Several important indicators after treatment in the two groups were scored,the effects between different groups were compared,and the effect of clinical treatment was evaluated.Results:The final effect was compared and analyzed.After data analysis,we found that the intracranial pressure of the observation group was lower,the volume of brain edema was significantly reduced(P<0.05),and the NIH Stroke Scale/Score(NIHSS)was lower(P<0.05).Conclusion:Using mannitol combined with glycerol fructose can achieve better treatment effect by significantly improving the problem of brain edema.

脑水肿(Cerebral edema)的治疗

脑水肿是由于多种病因引起的脑细胞水肿而致的脑体积增大,颅内压增高,常危及生命。治疗原则一、去除病因,切断继续的诱发因素。二、降低颅内压力,保持脑组织的灌注压。三、改善脑缺氧及脑代谢障碍。治疗方案在治疗原发病的基础上,消除脑水肿与降低颅内压的基本方法是减少脑容积、脑脊液量、脑减压及改善脑循环(CBF)等。(一)减少脑容积此方案列为首选。1.脱水治疗(1)脱水原则①患者血压必须维持在80~90/50~60mmHg以上,肾功能良好;②脱水程度恰到好处,如两眼稍下陷,眼球张力减低,压之稍软,皮肤仍保持弹性。

Over hydration in diabetic ketoacidosis may increase the risk of cerebral edema in children

Objectives Over-hydration in diabetic ketoacidosis(DKA) may increase the risk of cerebral edema in children.Methods We have organized a prospective descriptive cohort study of 38pediatric patients aged 1month to 14years,who were diagnosed with DKA with 41episodes of diabetic ketoacidosis,presented to the pediatric emergency department at the First Affiliated Hospital of Xinjiang Medical University from January 2010to February 2012.This study was approved by the Ethics Committee of The First Affiliated Hospital of Xinjiang Medical University.Results The magnitude presentation of the percentile 25%-70% was in the ratio of 5.6%(3.4%-8.2%)(6.1±4).So there was no clinical and biochemical assessment variation needed.These both of the variations,all of the diabetic ketoacidosis patient approached.Further all the patient variations were not correlated with the amplitude of variation and magnitude presentation and did not affect the fluid concentration and the quantity of the fluid was 47.8mL / kg(36.556.3) in the first 12hours.Conclusion For the conclusion of the exact parameters and the magnitude variations of the fluid in the patients of diabetic ketoacidosis,all of the conformations need study on the larger scale.

Influence of rotating magnetic field on cerebral infarction volume, cerebral edema and free radicals metabolism after cerebral ischemia/reperfusion injury in rats

BACKGROUND: It has shown that magnetic field can improve blood circulation, decrease blood viscosity, inhibit free radicals, affect Ca2+ flow in nerve cells, control inflammatory and immunological reaction, and accelerate nerve cell regeneration. In addition, protective effect of magnetic field, which acts as an iatrophysics, on ischemic brain tissues has been understood gradually. OBJECTIVE: To investigate the effects of rotating magnetic field (RMF) on volume of cerebral infarction, cerebral edema and metabolism of free radicals in rats after cerebral ischemia/reperfusion injury. DESIGN: Randomized controlled animal study. SETTING: Rehabilitation Center of disabled children, Liaoniang; Department of Rehabilitation, the Second Affiliated Hospital, China Medical University; Department of Rehabilitation Physiotherapy, the First Affiliated Hospital, China Medical University. MATERIALS: A total of 70 healthy Wistar rats aged 18-20 weeks of both genders were selected and randomly divided into 3 groups: sham operation group with 12 rats, control group with 20 rats and treatment group with 38 rats. The treatment group included 4 time points: immediate reperfusion with 6 ones, 6-hour reperfusion with 20 ones, 12-hour reperfusion with 6 ones and 18-hour reperfusion with 6 rats. Main instruments were detailed as follows: magnetic head of rotating magnetic device was 6 cm in diameter; magnetic induction intensity at the surface of magnetic head was 0.25 T in silence; the maximal magnetic induction intensity was 0.09 T at the phase of rotation; the average rotating speed was 2500 r per minute. METHODS: The experiment was carried out in the China Medical University in March 2003. Focal cerebral ischemic animal models were established with modified Longa’s method. Operation was the same in the sham operation, but the thread was inserted as 10 mm. Neurologic impairment was assessed with 5-rating method to screen out cases. Those survivals with grade 1 and grade 2 after ischemia for 2 hours and reperfusion for 24 hours were included in the control group and treatment group. Those in the sham operation group and control group were not treated with RMF. Magnetic head was directed towards the head of rats of the treatment group, and the magnetic head was about 7 mm from skin, treated for 15 minutes. The rats were decapitated to take out brains at 24 hours after reperfusion in each group. Water content of brain and volume of cerebral infarction were assessed with wet-dry weight method and TTC staining, respectively. Activity of superoxide dismutase (SOD), content of malondialdehyde (MDA) and change of brain histomorphology in brain tissue of ischemic side were analyzed. MAIN OUTCOME MEASURES: ① Volume of cerebral infarction and changes of water content in brain; ② measurements of SOD and MDA contents in brain tissue of rats in all groups. RESULTS: A total of 70 qualified animals were involved in the final analysis after rejecting the death and unqualified animal models. ① Water content of brain: Water content of brain in the treatment was less than that in the control group at any time point except the immediate time point, and cerebral edema was relieved [(2.48±0.22)%, (2.32±0.19)%, (2.23±0.36)%, (2.91±0.44)%, P < 0.05]. In addition, there were no significant differences among 6-hour, 12-hour and 18-hour reperfusion groups (P > 0.05). ② Volume of cerebral infarction: The absolute volume of cerebral infarction in the treatment group was smaller than that in the control group [(128.21±15.05), (171.22±40.50) mm3, t =2.438, P < 0.05], and the relative volume of cerebral infarction was smaller than that in the control group [(20.22±1.44)%, (25.17±3.85)%, t =2.95, P < 0.05]. ③ Contents of SOD and MDA in brain tissues: Compared with the control group, the SOD content in the brain tissue in the treatment group increased [(54.54±3.85), (69.52±5.88) kNU/g, t =5.568, P < 0.05], while the MDA content decreased [(0.85±0.06), (1.03±0.09) μmol/g, t =4.076, P < 0.05]. ④ General morphological observation: General morphology manifested that the edema was distinct in the right cerebral hemisphere in the control group, showing fat-like white, shallow anfractuosity, flat gyria, brittle tissue and easy to break up. The edema of right cerebral hemisphere was light and surface was hyperaemia in the treatment group. CONCLUSION: RMF may improve anti-oxidative ability of brain tissue of rats with acute focal cerebral ischemia/reperfusion injury and reduce volume of cerebral infarction and degrees of cerebral edema.

Risk factors and predictive model of cerebral edema after road traffic accidents-related traumatic brain injury

Purpose:Cerebral edema(CE)is the main secondary injury following traumatic brain injury(TBI)caused by road traffic accidents(RTAs).It is challenging to be predicted timely.In this study,we aimed to develop a prediction model for CE by identifying its risk factors and comparing the timing of edema occurrence in TBI patients with varying levels of injuries.Methods:This case-control study included 218 patients with TBI caused by RTAs.The cohort was divided into CE and non-CE groups,according to CT results within 7 days.Demographic data,imaging data,and clinical data were collected and analyzed.Quantitative variables that follow normal distribution were presented as mean±standard deviation,those that do not follow normal distribution were presented as median(Q1,Q3).Categorical variables were expressed as percentages.The Chi-square test and logistic regression analysis were used to identify risk factors for CE.Logistic curve fitting was performed to predict the time to secondary CE in TBI patients with different levels of injuries.The efficacy of the model was evaluated using the receiver operator characteristic curve.Results:According to the study,almost half(47.3%)of the patients were found to have CE.The risk factors associated with CE were bilateral frontal lobe contusion,unilateral frontal lobe contusion,cerebral contusion,subarachnoid hemorrhage,and abbreviated injury scale(AIS).The odds ratio values for these factors were 7.27(95%confidence interval(CI):2.08-25.42,p=0.002),2.85(95%CI:1.11-7.31,p=0.030),2.62(95%CI:1.12-6.13,p=0.027),2.44(95%CI:1.25-4.76,p=0.009),and 1.5(95%CI:1.10-2.04,p=0.009),respectively.We also observed that patients with mild/moderate TBI(AIS≤3)had a 50%probability of developing CE 19.7 h after injury(χ^(2)=13.82,adjusted R2=0.51),while patients with severe TBI(AIS>3)developed CE after 12.5 h(χ^(2)=18.48,adjusted R2=0.54).Finally,we conducted a receiver operator characteristic curve analysis of CE time,which showed an area under the curve of 0.744 and 0.672 for severe and mild/moderate TBI,respectively.Conclusion:Our study found that the onset of CE in individuals with TBI resulting from RTAs was correlated with the severity of the injury.Specifically,those with more severe injuries experienced an earlier onset of CE.These findings suggest that there is a critical time window for clinical intervention in cases of CE secondary to TBI.

Reversible leukoencephalopathy with seizures:a case of severe high-altitude cerebral edema

Background Acute high-altitude illness(AHAI)refers to a series of syndromes including acute mountain sickness(AMS),high-altitude pulmonary edema(HAPE)and high-altitude cerebral edema(HACE).Among these,HACE is a severe and potentially life-threatening condition that can occur when individuals ascend to high altitudes.It is often characterized by ataxia,confusion,and altered mental status.Without appropriate treatment,HACE can rapidly progress to coma,but seizures are infrequent in occurrence.Case presentation Here,we report a severe HACE patient with coma and status epilepticus.The patient is a 23-year-old male who was visiting Lhasa for the first time.He initially experienced headaches and dizziness on the first day,and then he was found in coma with limb convulsions on the next day.Immediate medical attention was sought,and brain CT and MRI scans showed reversible white matter lesions,especially in the corpus callosum and subcortical white matter.Although the lesions disappeared on T1 and T2 sequences,microbleeds were observed on the SWI sequence.After treatment with tracheal intubation,glucocorticoids and hyperbaric oxygen,the cerebral edema has resolved and the clinical symptoms improved,the patient has no seizures anymore.Conclusions HACE typically follows AMS and poses a significant risk to life.Clinical manifestations mainly include ataxia,alterations of behavior,and impaired consciousness,with severe cases progressing to coma.Seizures,though rarely observed,may occur.Imaging shows reversible white matter lesions,with microbleeds being a significant and persistent imaging marker over time.Administration of glucocorticoids plays a crucial role in treatment.Despite experiencing seizures,this patient did not experienced any further episodes once his condition improved.

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

NRF1-mediated microglial activation triggers high-altitude cerebral edema

High-altitude cerebral edema(HACE)is a potentially fatal encephalopathy associated with a time-dependent exposure to the hypobaric hypoxia of altitude.The formation of HACE is affected by both vasogenic and cytotoxic edema.The over-activated microglia potentiate the damage of blood-brain barrier(BBB)and exacerbate cytotoxic edema.In light with the activation of microglia in HACE,we aimed to investigate whether the over-activated microglia were the key turning point of acute mountain sickness to HACE.In in vivo experiments,by exposing mice to hypobaric hypoxia(7000 m above sea level)to induce HACE model,we found that microglia were activated and migrated to blood vessels.Microglia depletion by PLX5622 obviously relieved brain edema.In in vitro experiments,we found that hypoxia induced cultured microglial activation,leading to the destruction of endothelial tight junction and astrocyte swelling.Up-regulated nuclear respiratory factor 1(NRF1)accelerated pro-inflammatory factors through transcriptional regulation on nuclearfactorkappa B p65(NF-kB p65)and mitochondrial transcription factorA(TFAM)in activated microglia under hypoxia.NRF1 also up-regulated phagocytosis by transcriptional regulation on caveolin-1(CAV-1)and adaptorrelated protein complex 2 subunit beta(AP2B1).The present study reveals a new mechanism in HACE:hypoxia over-activates microglia through up-regulation of NRF1,which both induces inflammatory response through transcriptionally activating NF-kB p65 and TFAM,and enhances phagocytic function through up-regulation of CAV-1 and AP2B1;hypoxia-activatedmicroglia destroy the integrity of BBB and release pro-inflammatory factors that eventually induce HACE.

Effect of ischemic postconditioning on cerebral edema and the AQP4 expression following hypoxic-eschemic brain damage in neonatal rats

Background:A rat model for neonatal hypoxic-ischemic brain damage(HIBD)was established to observe the effect of ischemic postconditioning(IPostC)on cerebral edema and the AQP4 expression following HIBD and to verily the neuroprotection of IPostC and the relationship between changes of AQP4 expression and cerebral edema.Methods:Water content was measured with dry-wet method,and AQP4 transcription and the protein expression of the lesions were detected with real-time PCR and immunohistochemistry staining,respectively.Results:Within 6-48 hours,the degree of ipsilateral cerebral edema was significantly lower in IPostC-15 s/15 s group than in HIBD group.Similar to the HIBD group,the AQP4 transcription and expression in the IPostC group showed a downward and then upward trend.But the expression was still more evident in the HIBD group than in the IPostC-15 s/15 s group.From 24 to 48 hours,IPostC-15 s/15 s decreased the slowing down expression of AQP4.Conclusion:IPostC has neuroprotective effect on neonatal rats with HIBD and it may relieve cerebral edema by regulating the expression of AQP4.

Effect of dexamethasone by local treatment on cerebral edema and serum myelin basic protein after brain injury in rabbits

To explore the effect of dexamethasone by local treatment on cerebral edema and brain damage after brain injury. Methods: Twenty-two rabbits were classified into 2 groups, Group A (the control group, n=11) and Group B (the treated group, n=11). An rabbit brain contusion model was made by bone windowplasty by extradural hitting. Group B was treated by local infiltrating and spraying of dexamethasone at equidistance to lesions. Group A was given normal saline in the same way as Group B. The changes of moisture in brain tissues and serum myelin basic protein (MBP) were observed. Results: The percentage of water content in damaged hemisphere in Group A and Group B was 81.75 %± 0.56 % and 79.45 %± 0.52 % respectively. There was a significant difference between the 2 groups (P< 0.05 ). The normal level of MBP was 1.66 μg/L± 0.71 μg/L, while the value of MBP in Group A and Group B were 5.98 μg/L± 2.08 μg/L and 3.15 μg/L± 1.09 μg/L separately. The level of MBP in Group A and Group B were higher than normal level and there was also a significant difference between Group A and Group B (P< 0.05 ). Conclusions: The results of our study showed that the brain moisture and MBP in serum were increased after brain injury while reduced after treatment with dexamethasone. It is demonstrated that local treatment of brain injury with dexamethasone has an obvious therapeutic effect on cerebral edema and serum MBP.

Topical application of adipose tissuederived mesenchymal stem cells(ADMSCs)reduced cerebral edema in experimental traumatic brain injury(TBI)-a preliminary study

Background:Our previous studies showed that topical application of mesenchymal stem cells(MSCs)improved functional recovery in rat traumatic brain injury(TBI)model,and hypoxic precondition further enhanced the therapeutic effects of MSCs.There was no previous study on the attenuation of cerebral edema by MSCs.We investigated whether topical application of normoxic and hypoxic MSCs could reduce cerebral edema in an experimental TBI model.Methods:Two million normoxic(N=24)and hypoxic(N=24)MSCs were applied topically to exposed the cerebral cortex in a controlled cortical impact(CCI)model.The MSCs were fixed in position with fibrin glue.No treatment was given to control animals(TBI only:n=24).After surgery,four animals in each group were sacrificed daily(day 1 to day 6)for edema evaluation.Normal animals without TBI were used as reference(n=4).The expressions of GFAP,AQP4,and MMP9 were also investigated by immunofluorescence staining and RT-PCR at day 3.Results:The edema peaked within 3 days after TBI.Compared with the control,hypoxic MSCs reduced brain water content significantly(p<0.05).Both hypoxic and normoxic MSCs downregulated the expression of MMP9 and normalized AQP4 distribution to astrocyte end feet.Conclusion:Our preliminary study showed that topical application of hypoxic MSCs suppressed both vasogenic and cytotoxic edema formation.

De novo mutation of NAXE(APOAIBP)-related early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1:A case report

BACKGROUND Early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1(PEBEL1)is a rare autosomal recessive severe neurometabolic disease.The aim of this study was to investigate the clinical characteristics and genetic pathogenicity of PEBEL1 caused by rare NAXE(or APOA1BP)-related defects.CASE SUMMARY The patient was a girl aged 2 years and 10 mo.She was hospitalized due to walking disorder for>40 d.The clinical manifestations were ataxia,motor function regression,hypotonia,and eyelid ptosis.Within 1 mo of hospitalization,she developed sigh breathing,respiratory failure,cerebellar edema and brain hernia,and finally she died.Changes were found in cranial imaging,including cerebellar edema accompanied by symmetrical myelopathy.Through whole exome sequencing,we detected NAXE compound heterozygous variation(NM 144772.3)c.733A>C(p.Lys245Gln,dbSNP:rs770023429)and novel variation c.370G>T(p.Gly124Cys)in the germline gene.The clinical features and core phenotypes of this case were consistent with 18 previously reported cases of PEBEL1.CONCLUSION This is the first case of NAXE-related PEBEL1 with severe clinical phenotype in China' Mainland.The p.Gly124Cys mutation discovered in this case has enriched the pathogenic variation spectrum of NAXE.

Gene interference regulates aquaporin-4 expression in swollen tissue of rats with cerebral ischemic edema Correlation with variation in apparent diffusion coefficient

To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 pL shRNA- aquaporin-4 （control group） or siRNA- aquaporin-4 solution （1：800） （RNA interference group） into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25- 6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5 4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson＇s correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient （r = -0.806, P 〈 0.01）. These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracelfular edema with time-effectiveness. Moreover, diffusion-weighted MRI can accurately detect intracellular edema.

Relationship between AQP4 expression and DWI of the cerebral ischemic edema in rats

Objective: To study the correlation between aquaporin-4 ( AQP4) expression and diffusion-weighted imaging ( DWI) in the process of ischemic brain edema for the molecular biologic mechanism of DWI. Methods: A total of 34 Wistar rats were divided into 8 groups randomly: Non-operated group (n = 4) , sham-operated group (n = 6) , and operated group, receiving right middle cerebral artery occlusion ( MCAO) for 15 and 30 min, and 1,3,6 and 24 h respectively (6 subgroups, n =4). All groups were imaged with DWI and T2WI. The apparent diffusion coefficient (ADC) , relevant density (rd) and relevant area (rs) of hyperintensity of the lesions on DWI and T2WI were measured. Relevant ADC (rADC) , relevant area of immunohistochemical staining for AQP4 (rS) , optical density of AQP4 hybridization (a) were calculated. After that the animals were sacrificed and perfused at different time intervals, correlations between DWI, ADC, and AQP4 expression (rS, a) in ischemic tissue was made. Results: There was a significant correlation between rS and a ( r = 0. 949 ). The abnormal high intensity was found in DWI of the ipsilateral MAC territory at 15 min after MCAO. The ADC value decreased quickly within 1 h after MCAO, the rd and rs of DWI increased rapidly and the expression of AQP4 increased quickly, too. However, there was no change on the T2WI. In the period of time (15 min - 1 h) , the AQP4 expression( a) had a strong relation to the rd and rs( r = 0. 914, 0. 895). With the progress of the time, the ADC value of MCAO decreased further to (2.1±0.6)×10-4 mm2/s at 3 h, and then followed an increased slowly till 24 h, but the rd and the rs as well as the expression of AQP4 continuously increased during the stage. The T2WI detected the lesion at the average time (1.4 h) after MCAO, and the rs of T2WI was less than that of DWI at the same time in the same layer (P < 0.05). Conclusion: The results imply that high expression of AQP4 may play a key role in ischemic brain edema. It is, certainly, one of the important reasons of the DWI molecular biologic mechanism in the cerebral ischemia.

Induced neural stem cells regulate microglial activation through Akt-mediated upregulation of CXCR4 and Crry in a mouse model of closed head injury

Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and repair.We previously reported that induced neural stem cells can modulate the behavior of activated microglia via CXCL12/CXCR4 signaling,influencing their activation such that they can promote neurological recovery.However,the mechanism of CXCR4 upregulation in induced neural stem cells remains unclear.In this study,we found that nuclear factor-κB activation induced by closed head injury mouse serum in microglia promoted CXCL12 and tumor necrosis factor-αexpression but suppressed insulin-like growth factor-1 expression.However,recombinant complement receptor 2-conjugated Crry(CR2-Crry)reduced the effects of closed head injury mouse serum-induced nuclear factor-κB activation in microglia and the levels of activated microglia,CXCL12,and tumor necrosis factor-α.Additionally,we observed that,in response to stimulation(including stimulation by CXCL12 secreted by activated microglia),CXCR4 and Crry levels can be upregulated in induced neural stem cells via the interplay among CXCL12/CXCR4,Crry,and Akt signaling to modulate microglial activation.In agreement with these in vitro experimental results,we found that Akt activation enhanced the immunoregulatory effects of induced neural stem cell grafts on microglial activation,leading to the promotion of neurological recovery via insulin-like growth factor-1 secretion and the neuroprotective effects of induced neural stem cell grafts through CXCR4 and Crry upregulation in the injured cortices of closed head injury mice.Notably,these beneficial effects of Akt activation in induced neural stem cells were positively correlated with the therapeutic effects of induced neural stem cells on neuronal injury,cerebral edema,and neurological disorders post–closed head injury.In conclusion,our findings reveal that Akt activation may enhance the immunoregulatory effects of induced neural stem cells on microglial activation via upregulation of CXCR4 and Crry,thereby promoting induced neural stem cell–mediated improvement of neuronal injury,cerebral edema,and neurological disorders following closed head injury.

Blood-letting punctures at twelve Jing-Well points of the hand can treat cerebral ischemia in a similar manner to mannitol

A rat model of middle cerebral artery permanent occlusion was established using the modified Longa method. Successfully established model animals were treated by blood-letting puncture at twelve Jing-Well points of the hand, and/or by injecting mannitol into the caudal vein twice daily. Brain tissue was collected at 24, 48 and 72 hours after modeling, and blood was collected through the retinal vein before Evans blue was injected, approximately 1 hour prior to harvesting of brain tissue. Results showed that Evans blue leakage into brain tissue and serum nitric oxide synthase activity were significantly increased in model rats. Treatment with blood-letting punctures at twelve Jing-Well points of the hand and/or injection of mannitol into the caudal vein reduced the amount of Evans blue leakage into the brain tissue and serum nitric oxide synthase activity to varying degrees. There was no significant difference between single treatment and combined treatment. Experimental findings indicate that blood-letting punctures at twelve Jing-Well points of the hand can decrease blood-brain barrier permeability and serum nitric oxide synthase activity in rats following middle cerebral artery occlusion, and its effect is similar to that of mannitol injection alone and Jing-Well points plus mannitol injection.