Neuroprotective effects of meloxicam on transient brain ischemia in rats:the two faces of anti-inflammatory treatments

The inflammato ry response plays an important role in neuroprotection and regeneration after ischemic insult.The use of non-ste roidal anti-inflammatory drugs has been a matter of debate as to whether they have beneficial or detrimental effects.In this context,the effects of the anti-inflammatory agent meloxicam have been scarcely documented after stro ke,but its ability to inhibit both cyclooxygenase isoforms(1 and 2) could be a promising strategy to modulate postischemic inflammation.This study analyzed the effect of meloxicam in a transient focal cerebral ischemia model in rats,measuring its neuroprotective effect after 48 hours and 7 days of reperfusion and the effects of the treatment on the glial scar and regenerative events such as the generation of new progenitors in the subventricular zone and axonal sprouting at the edge of the damaged area.We show that meloxicam’s neuroprotective effects remained after 7 days of reperfusion even if its administration was restricted to the two first days after ischemia.Moreover,meloxicam treatment modulated glial scar reactivity,which matched with an increase in axonal sprouting.However,this treatment decreased the formation of neuronal progenitor cells.This study discusses the dual role of anti-inflammatory treatments after stro ke and encourages the careful analysis of both the neuroprotective and the regenerative effects in preclinical studies.

Transplantation of X-box-binding protein-1 gene-modified neural stem cells in the lateral ventricle of brain ischemia rats

X-box-binding protein-1 （XBP-1） is an essential transcription factor in endoplasmic reticulum stress In this study, XBP-1 gene-transfected neural stem cells （NSCs） were transplanted into lesion sites to ensure stability and persistent expression of XBP-1, resulting in the exertion of anti-apoptotic effects. Simultaneously, XBP-1 gene transfection promotes the survival and differentiation of transplanted NSCs. Results from this study demonstrated that survival, proliferation and differentiation of XBP-1 g^ne-modified NSCs were enhanced when compared to unmodified NSCs at 28 days post-transplantation （P 〈 0.05）. A diminished number of apoptotic neural cells increased Bcl-2 expression and reduced Bax expression, and were observed in the ischemic region of the XBP-1-NSCs group （P 〈 0.05）. These results indicated that modification of the XBP-1 gene enhances the survival and migration of NSCs in vivo and decreases the occurrence of apoptosis.

Pathological verification of corticospinal tract Wallerian degeneration in a rat model of brain ischemia

Although neuroimaging is commonly utilized to study Wallerian degeneration, it cannot display Wallerian degeneration early after brain injury. In the present study, we attempted to examine pathologically the process of Wallerian degeneration early after brain injury. Cerebral peduncle demyelination was observed at 3 weeks post brain ischemia, followed by demyelination in the cervical enlargement at 6 weeks. Anterograde tracing of the corticospinal tract with biotinylated dextran amine showed that following serious neurologic deficit, the tracing of the corticospinal tract of the intemal capsule, cerebral peduncle, and cervical enlargement indicated serious Wallerian degeneration.

Magnetic resonance imaging tracing of transplanted bone marrow mesenchymal stem cells in a rat model of cardiac arrest-induced global brain ischemia

BACKGROUND： Numerous studies have shown that magnetic resonance imaging （MRI） can detect survival and migration of super paramagnetic iron oxide-labeled stem cells in models of focal cerebral infarction. OBJECTIVE： To observe distribution of bone marrow mesenchymal stem cells （BMSCs） in a rat model of global brain ischemia following cardiac arrest and resuscitation, and to investigate the feasibility of tracing iron oxide-labeled BMSCs using non-invasive MRI. DESIGN, TIME AND SETTING： The randomized, controlled, molecular imaging study was performed at the Linbaixin Medical Research Center, Second Affiliated Hospital, Sun Yat-sen University, and the Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, China from October 2006 to February 2009. MATERIALS： A total of 40 clean, Sprague Dawley rats, aged 6 weeks and of either gender, were supplied by the Experimental Animal Center, Sun Yat-sen University, China, for isolation of BMSCs. Feridex （iron oxide）, Gyroscan Inetra 1.5T MRI system, and cardiopulmonary resuscitation device were used in this study. METHODS： A total of 30 healthy, male Sprague Dawiey rats, aged 6 months, were used to induce ventricular fibrillation using alternating current. After 8 minutes, the rats underwent 6-minute chest compression and mechanical ventilation, followed by electric defibrillation, to establish rat models of global brain ischemia due to cardiac arrest and resuscitation. A total of 24 successful models were randomly assigned to Feridex-labeled and non-labeled groups （n = 12 for each group）. At 2 hours after resuscitation, 5 ×10^8 Feridex-labeled BMSCs, with protamine sulfate as a carrier, and 5 ×10^6 non-labeled BMSCs were respectively transplanted into both groups of rats through the right carotid artery （cells were harvested in 1 mL phosphate buffered saline）. MAIN OUTCOME MEASURES： Feridex-labeled BMSCs were observed by Prussian blue staining and electron microscopy. Signal intensity, celluar viability, and proliferative capacity of BMSCs were measured using MRI, Trypan blue test, and M-IT assay, respectively. Distribution of transplanted cells was observed in rats utilizing MRI and Prussian blue staining prior to and 1, 3, 7, and 14 days after transplantation. RESULTS： Prussian blue staining displayed many blue granules in the Feridex-labeled BMSCs. High density of iron granules was observed in the cytoplasm under electron microscopy. According to MRI results, and compared with the non-labeled group, the signal intensity was decreased in the Feridex-labeled group （P 〈 0.05）. The decrease was most significant in the 50 pg/mL Feridex-labeled group （P 〈 0.01）. There were no significant differences in celluar viability and proliferation of BMSCs between the Feridex-labeled and non-labeled groups after 1 week （P 〉 0.05）. Low-signal lesions were detected in the rat hippocampus and temporal cortex at 3 days after transplantation. The low-signal lesions were still detectable at 14 days, and positively stained cells were observed in the hippocampus and temporal cortex using Prussian blue staining. There were no significant differences in signal intensity in the non-labeled group. CONCLUSION： BMSC transplantation traversed the blood-brain barrier and distributed into vulnerable zones in a rat model of cardiac arrest-induced global brain ischemia. MRI provided a non-invasive method to in vivo dynamically and spatially trace Feridex-labeled BMSCs after transplantation.

Phosphorylation of tau protein over time in rats subjected to transient brain ischemia

Transient brain ischemia has been shown to induce hyperphosphorylation of the micro- tubule-associated protein tau. To further determine the mechanisms underlying these processes, we investigated the interaction between tau, glycogen synthase kinase （GSK）-313 and protein phos- phatase 2A. The results confirmed that tau protein was dephosphorylated during brain ischemia; in addition, the activity of GSK-3β was increased and the activity of protein phosphatase 2A was de- creased. After reperfusion, tau protein was hyperphosphorylated, the activity of GSK-3β was de- creased and the activity of protein phosphatase 2A remained low. Importantly, the interaction of tau with GSK-3β and protein phosphatase 2A was altered during ischemia and reperfusion. Lithium chloride could affect tau phosphorylation by regulating the interaction of tau with GSK-3β and pro- tein phosphatase 2A, and improve learning and memory ability of rats after transient brain ischemia. The present study demonstrated that it was the interaction of tau with GSK-3β and protein phos- phatase 2A, rather than their individual activities, that dominates the phosphorylation of tau in tran- sient brain ischemia. Hyperphosphorylated tau protein may play an important role in the evolution of brain injury in ischemic stroke. The neuroprotective effects of lithium chloride partly depend on the inhibition of tau phosphorylation during transient brain ischemia.

Protective effects of combined Astragalus membranaceus and magnesium ions on global brain ischemia

The traditional Chinese herb Astragalus membranaceus is a well-known treatment for neurological diseases and is considered to exhibit anti-dementia properties.This study investigated the synergistic effects of magnesium ions and Astragalus membranaceus on global brain ischemia in rats.4＇-6-diamidino-2-phenylindole staining demonstrated that the number of living neurons was significantly greater in the rat hippocampus after administration of a combination of Astragalus membranaceus and magnesium,compared with a vehicle group,an Astragalus membranaceus alone group,and a magnesium alone group.Western blot assay revealed that cleaved Caspase-3 protein expression was significantly reduced in the rat hippocampus in the combined Astragalus membranaceus and magnesium group compared with the Astragalus membranaceus alone group and the magnesium alone group.The results suggested that the combination of Astragalus membranaceus and magnesium exhibits a stronger neuroprotective effect on global brain ischemia in rats compared with Astragalus membranaceus or magnesium alone.This effect was associated with decreased Caspase-3 expression.

Increased expression of receptor for advanced glycation end-products worsens focal brain ischemia in diabetic rats

A rat model of diabetes mellitus was induced by a high fat diet, followed by focal brain ischemia induced using the thread method after 0.5 month. Immunohistochemistry showed that expression of receptor for advanced glycation end-products was higher in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Western blot assay revealed increased phosphorylated c-Jun N-terminal kinase expression, and unchanged phosphorylated extracellular signal-regulated protein kinase protein expression in the ischemic cortex of diabetic rats compared with non-diabetic rats with brain ischemia. Additionally, phosphorylated p38 mitogen-activated protein kinase protein was not detected in any rats in the two groups. Severity of limb hemiplegia was worse in diabetic rats with brain ischemia compared with ischemia alone rats. The results suggest that increased expression of receptor for advanced glycation end-products can further activate the c-Jun N-terminal kinase pathway in mitogen-activated protein kinase, thereby worsening brain injury associated with focal brain ischemia in diabetic rats.

Protection of 3'-methoxy-puerarin against focal brain ischemia and its association with c-fos expression

The present study established a rat model of focal brain ischemia by occlusion of the middle cerebral artery covered with FeCl3, and investigated the protective effect of 3＇-methoxy-puerarin. Hippocampal and cortical c-fos gene expression was determined using in situ hybridization. Results showed that 3＇-methoxy-puerarin reduced neurological deficit scores, cerebral infarcted zone and water content of brain tissues, dramatically increased the activity of catalase and glutathione peroxidase in the ischemia zone of the hippocampus, increased the activity of catalase in the cortex, decreased lipid peroxide and lactic acid contents in the hippocampus and cerebral cortex, and down-regulated c-fos gene expression in brain ischemic rats. Results demonstrated that 3＇-methoxy-puerarin exhibited cerebroprotective effects against focal brain ischemia, which involved c-fos gene expression.

Editor's Choice——Acupuncture and neural regeneration after brain ischemia

Acupuncture at acupoints can improve the functions of distal organs. Neuropathological studies have shown that electroacupuncture can significantly reduce the infarct volume, and improve the proportions of injured corpus striatum cells and residual cortical cells. Acupuncture-like sense stimulation can activate various conduction pathways that induce changes in nervous system activities.

Swimming Performance: A Strategy to Evaluate Motor Dysfunction after Brain Ischemia in Mice

We have previously reported that sequential common artery sectioning (SCAS) in mice produces a reproducible pattern of mortality, extensive brain damage and a wide range of measurable neurobehavioral alterations that include motor incoordination and forelimb flexion. The present study describes a comprehensive method to assess motor functional outcome after brain ischemia produced by SCAS using swimming behavior. We found that after the second artery occlusion the time for completion of the swimming task significantly increased and the swimming pattern alterations observed in the ischemic mice showed no evidence of recovery (up to 96 h). We view the swimming performance strategy described here as a sensitive, simple and economic procedure to assess motor performance after brain ischemia.

The Influence of Remote Ischemic Conditioning on Focal Brain Ischemia in Rats

Despite obvious progress in the treatment of acute forms of ischemic stroke, the risk of this condition remains unacceptably high. Brain infarction in the middle cerebral artery basin occurs in patients with atherosclerosis. The onset of the brain infarction is facilitated by the cessation of circulation (embolism) in conditions of insufficient collateral circulation. The extent of the infarct zone is determined by neuronal death and impaired microcirculation. The development of new methods for effective targeted restorative stroke therapy is crucial for restorative treatment and reducing the risk of mortality after stroke. Remote ischemic conditioning (RIC) is an approach to limiting reperfusion injury in the ischemic region of the brain after focal ischemia. One of the most commonly used in vivo models in stroke studies is the filament model of Middle Cerebral Artery Occlusion (MCAO) in rats. In our experiment, it was performed for 30 min (J. Koizumi) with subsequent 48-hour reperfusion. Within the first 24 hours after the start of reperfusion several short episodes of ischemia in low limbs were induced. After 48 hours of reperfusion the brains were harvested and stained with TTC. Then we evaluated the effect of RIC within 24 hours ex vivo in rats’ brains, as well as syndecan-1 plasma concentration. Infarct area was assessed by means of Image-Pro program with statistical analysis. Infarct volumes in the model group (31.97% ± 2.5%) were significantly higher compared to the values in the RIC group 48 hours after ischemia-reperfusion (13.6% ± 1.3%) (*P < 0.05). A significant reduction in the area of infarction after RIC is likely due to the effect on the regulation of collateral blood flow in the ischemia area. On the second day after ischemia-reperfusion, tissue swelling was reduced in the RIC group compared to the model group. Analysis of the average concentration of Syndecan-1 revealed the difference between model and RIC groups. Syndecan-1, endothelial glycocalyx protein, might be the regulator which performs vascular control of the interaction with inflammatory cell and is responsible for mediate effect of remote ischemic conditioning on the restriction of ischemic-reperfusion injury.

Effects of Moxibustion Pretreating on SOD and MDA in the Rat of Global Brain Ischemia

Objective: To probe into the mechanism of moxibustion preconditioning in preventive brain-protecting effect. Methods: The global brain ischemia rat model was developed by blocking 4 arteries. Seventy-eight Wistar male rats were randomly divided into 5 groups: a normal control group, a sham-operation group, a brain ischemia group, a brain ischemia preconditioning group, a moxibustion pretreating group. The brains in the 5 groups were taken at 24 h, 48 h, and 72 h after operation respectively. Superoxide dismulase (SOD) activity was determined with xanthine oxidase method and malondialdehyde (MDA) content with thiobarbituric acid method. Results: After the operation, in the moxibustion preconditioning group, SOD activity significantly increased, especially 24 h after moxibustion preconditioning; and MDA content decreased, with a very significant difference as compared with that of the cerebral ischemia group (P<0.01). Conclusion: Moxibustion preconditioning protects the ischemic and anoxic brain tissue by increasing the activity of endogenous antioxidase.

Naoxintong dose effects on inflammatory factor expression in the rat brain following focal cerebral ischemia

BACKGROUND： Certain components of tetramethylpyrazine, a traditional Chinese medicine, exhibit protective effects against brain injury. OBJECTIVE： To investigate the effects of different Naoxintong doses on expression of nuclear factor-kappa B （ kB）, interleukin-6, tumor necrosis factor-α, and complement 3 in rats following focal cerebral ischemia. DESIGN, TIME AND SETTING： The randomized experiment was performed at the Laboratory of Neurology, Second Hospital of Hebei Medical University from June 2004 to June 2006. MATERIALS： A total of 150 adult, healthy, male, Sprague Dawley rats, weighing 280-320g, were selected. Naoxintong powder （mainly comprising szechwan lovage rhizome, milkvetch root, danshen root, and radix angelicae sinensis） was obtained from Buchang Pharmacy Co., Ltd. in Xianyang City of Shanxi Province of China, lot number 040608. METHODS： The rats were randomly assigned into sham operation, saline, high-dose Naoxintong, moderate-dose Naoxintong, and low-dose Naoxintong groups, with 30 rats in each group. Rat models of middle cerebral artery occlusion were established using the suture method, with the exception of the sham operation group. Rats in the high-dose, moderate-dose and low-dose Naoxintong groups received 4, 2, and 1 g/kg Naoxintong respectively, by gavage. Rats in the saline group were treated with 1 mL saline by gavage All rats were administered by gavage at 5 and 23 hours following surgery, and subsequently, once per day. MAIN OUTCOME MEASURES： At 6, 24, 48, 72 hours, and 7 days following model establishment, brain water content was measured. Histopathological changes in brain tissues were detected using hematoxylin-eosin staining. Expression of nuclear factor- kB, interleukin-6, tumor necrosis factor- α, and complement 3 was examined by immunohistochemistry. RESULTS： A total of 150 rats were included in the final analysis with no loss. Brain water content was significantly increased in the ischemic hemisphere of rats from the saline, as well as the high-dose, moderate-dose, and low-dose Naoxintong groups at 24 hours, which reached a peak at 48 hours. At 6, 24, 48, 72 hours, and 7 days, brain water content was greater in the ischemic hemisphere of rats from the saline, as well as the high-dose, moderate-dose, and low-dose Naoxintong groups, compared with the sham operation group （P 〈 0.05）. At 24 and 48 hours, brain water content was reduced in the high-dose and moderate-dose Naoxintong groups, compared to the saline and low-dose Naoxintong groups （P 〈 0.05）. In the saline, as well as high-dose, moderate-dose, and low-dose Naoxintong groups, neuronal edema was observed at 6 hours surrounding the ischemic sites. Inflammatory cells appeared at 24 hours, reached a peak at 48 hours, and gradually diminished. A small amount of glial cell proliferation and neuronal degeneration were observed in the hippocampus at 72 hours following infarction. Microglial proliferation and aggregation were detected at 7 days after infarction. Expression of nuclear factor- kB, interleukin-6, tumor necrosis factor-α, and complement 3 was significantly less in the high-dose, moderate-dose, and low-dose Naoxintong groups, compared to the sham operation group （P 〈 0.05）. Expression of the above-mentioned inflammatory cytokines was lower in rat brain tissues of the high-dose Naoxintong group, compared to the low-dose Naoxintong group （P 〈 0.05）. CONCLUSION： High-dose Naoxintong and moderate-dose Naoxintong significantly alleviated rat brain edema and decreased expression of nuclear factor-kB, interleukin-6, tumor necrosis factor-α, and complement 3 in brain tissues. The protective effect of high-dose Naoxintong was most significant.

Systemic delivery of microRNA for treatment of brain ischemia

Brain ischemia is the second leading cause of death and the third leading cause of disability in the world.Systemic delivery of microRNA,a class of molecules that regulate the expression of cellular proteins associated with angiogenesis,cell growth,proliferation and differentiation,holds great promise for the treatment of brain ischemia.However,their therapeutic efficacy has been hampered by poor delivery efficiency of microRNA.We report herein a platform technology based on microRNA nanocapsules,which enables their effective delivery to the disease sites in the brain.Exemplified by microRNA-21,intravenous injection of the nanocapsules into a rat model of cerebral ischemia could effectively ameliorate the infarct volume,neurological deficit and histopathological severity.

Met-Controlled Allosteric Module of Neural Generation as A New Therapeutic Target in Rodent Brain Ischemia

Objective To investigate a Met-controlled allosteric module(AM)of neural generation as a potential therapeutic target for brain ischemia.Methods We selected Markov clustering algorithm(MCL)to mine functional modules in the related target networks.According to the topological similarity,one functional module was predicted in the modules of baicalin(BA),jasminoidin(JA),cholic acid(CA),compared with I/R model modules.This functional module included three genes:Inppl1,Met and Dapk3(IMD).By gene ontology enrichment analysis,biological process related to this functional module was obtained.This functional module participated in generation of neurons.Western blotting was applied to present the compound-dependent regulation of IMD.Co-immunoprecipitation was used to reveal the relationship among the three members.We used IF to determine the number of newborn neurons between compound treatment group and ischemia/reperfusion group.The expressions of vascular endothelial growth factor(VEGF)and matrix metalloproteinase 9(MMP-9)were supposed to show the changing circumstances for neural generation under cerebral ischemia.Results Significant reduction in infarction volume and pathological changes were shown in the compound treatment groups compared with the I/R model group(P<0.05).Three nodes in one novel module of IMD were found to exert diverse compound-dependent ischemic-specific excitatory regulatory activities.An anti-ischemic excitatory allosteric module(AME)of generation of neurons(AME-GN)was validated successfully in vivo.Newborn neurons increased in BJC treatment group(P<0.05).The expression of VEGF and MMP-9 decreased in the compound treatment groups compared with the I/R model group(P<0.05).Conclusions AME demonstrates effectiveness of our pioneering approach to the discovery of therapeutic target.The novel approach for AM discovery in an effort to identify therapeutic targets holds the promise of accelerating elucidation of underlying pharmacological mechanisms in cerebral ischemia.

Gap junction communication involved in brain protection following focal ischemia and reperfusion in rats

BACKGROUND： Studies have suggested that gap junctions not only modulate the fate of the neocortex, but are also involved in maintaining homeostasis in the mature brain. However, the neuroprotective effects of gap junction communication following brain ischemic injury remain poorly understood. OBJECTIVE： To investigate the neuroprotective effects and possible mechanisms of gap junction communication following focal ischemia and reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the School of Basic Medical Sciences of Lanzhou University between June 2007 and May 2008. MATERIALS： Rabbit polyclonal anti-connexin 43 （Cx43） and gap junction blocking agent octanol were purchased from Sigma, USA; mouse monoclonal anti-rat glial fibrillary acidic protein （GFAP） was provided by Santa Cruz, USA; mouse monoclonal anti-rat CD11 b was produced by Abcam, England. METHODS： A total of 52 adult, male, Sprague Dawley rats were randomly assigned to three groups： sham-operated （n = 12）, vehicle control （n = 20）, and octanol-treated （n = 20）. Brain ischemia and reperfusion were induced by transient middle cerebral artery occlusion （MCAO） in vehicle control and octanol-treated groups, while no MCAO was administered to the sham-operated group. In the octanol-treated group, 5 mmol/kg octanol was dissolved in dimethyl sulfoxide （0.005% v/v） and was intraperitoneally injected 30 minutes prior to ischemic onset. Sham-operated and vehicle groups received equivalent volumes of dimethyl sulfoxide. MAIN OUTCOME MEASURES： Infarct volumes in ipsilateral striatum after MCAO were measured using cresyl violet dye; GFAP, CD11 b, and Cx43 expression in the ipsilateral striatum following MCAO were detected by immunohistochemistry; Western blot analysis was employed to determine Cx43 and GFAP expression. RESULTS： At 1 and 3 days following MCAO and reperfusion, ipsilateral striatum infarct volumes in the octanol group were significantly greater than in the vehicle group （P 〈 0.05）. There was no infarction in the sham-operated group. Cx43 and GFAP expression in the ipsilateral striatum of the octanol group was remarkably decreased compared with the vehicle group （P 〈 0.05）, and expression in the sham-operated group was less than in the other two groups （P 〈 0.05）. In the octanol-treated group, CD11 b expression was significantly increased compared with the vehicle group （P 〈 0.05）, and there were less CD11 b-immunoreactive cells in the sham-operated group compared with the other two groups （P 〈 0.05）. CONCLUSION： The pretreatment of blocking gap junction aggravated brain injury following MCAO. These results were possibly due to reduced astrocyte proliferation and activation, as well as reduced inflammatory response via activated microglia.

Pretreatment with candesartan protects brain against ischemia in normotensive rats

Objective Angiotensin Ⅱ (Ang-Ⅱ) increases NADPH oxidase activity and stimulates the production of reactive oxygen species (ROS) including superoxide anion through Ang Ⅱ AT1-receptor (AT1-R) activation. ROS is involved in various pathological processes in brain ischemia. We investigated whether the AT1-R blocker (ARB) candesartan can protect normotensive rats against brain ischemia. Methods After 2-week pretreatment with candesartan, rats were subjected to 2 hours middle cerebral artery occlusion-reperfusion (MCAO-R) and 24 hours later, the infarct volume, iNOS, and eNOS mRNA in the internal carotid artery was recorded and compared. Results Candesartan pretreatment reduced cerebral ischemia and oxidative brain damage after MCAO-R in normotensive rats, resulting in a decreased cortical infarct volume [0.5 mg/kg candesartan, (46.8±13.2)mm3; 1.0 mg/kg candesartan, (19.3±15.3)mm3 vs. control, (111.7±14.3)mm3; P<0.05, P<0.01, respectively]. Candesartan pretreatment increased the eNOS mRNA level in the internal carotid artery. Conclusion In normotensive rats exposed to MCAO-R, candesartan protectes against brain ischemia. This effect may represent a significant therapeutic advantage and may induce end-organ protection even at normal blood pressure.

Effects of “Nourishing Liver and Kidney” Acupuncture Therapy on Expression of Brain Derived Neurotrophic Factor and Synaptophysin after Cerebral Ischemia Reperfusion in Rats

The aim of the present study was to investigate the effect of ＂nourishing liver and kidney＂ acupuncture therapy on motor and cognitive deficits,and the underlying mechanism following cerebral ischemia-reperfusion（I/R） via increasing the expression of brain derived neurotrophic factor（BDNF） and synaptophysin（SYN） in the hippocampus.Healthy adult male SD rats were randomly divided into sham operation group（n=51）,model group（n=51）,acupuncture group（n=51） and acupuncture control group（n=51）.The middle cerebral I/R model was established.Acupunctures were performed in the acupuncture group and acupuncture control group at acupoints of Taixi（K103）,Taichong（ST09） of both sides,for 30 min once daily every morning.The animals in the sham operation group and model group were conventionally fed in the cage,without any intervention therapy.The rats of each group were assessed with modified neurological severity scores（m NSS）.The expression of BDNF and SYN in the hippocampus was detected by immunohistochemical SP method and the synaptic structure in hippocampus area was assessed morphologically and quantitatively at the 3rd,7th and 14 th day.The Morris water Maze（MWM） test was used to evaluate the rats＇ learning and memory abilities on the 15 th day after acupuncture.The animals in the acupuncture control group and sham operation group presented no neurological deficit.In the acupuncture group,the nerve functional recovery was significantly better than that in the model group at the 7th and 14 th day after modeling.The average MWM escape latency in the acupuncture group was shorter than that in the model group at the 3rd,4th and 5th day.The number of crossings of the platform quadrant in the acupuncture group was significantly more than that in the model group.At the each time point,the expression levels of BDNF and SYN in the hippocampal regions increased significantly in the model group as compared with the sham operation group and the acupuncture control group.In the acupuncture group,the expression levels of BDNF at the 7th and 14 th day increased more significantly than those in the model group.In the acupuncture group,the expression levels of SYN at the each time point increased more significantly than those in the model group.The post-synaptic density（PSD） was significantly increased and the synapse cleft width was narrowed in the acupuncture group as compared with other groups.The synaptic curvatures were improved obviously in the acupuncture group in contrast to the model group.It was concluded that the ＂nourishing liver and kidney＂ acupuncture therapy has positive effects on behavioral recovery,as well as learning and memory abilities,probably by promoting the expression of BDNF and SYN,and synaptic structure reconstruction in the ipsilateral hippocampus after I/R in rats.The ＂nourishing liver and kidney＂ acupuncture therapy can promote the functional recovery in rats after cerebral ischemia injury.

Inhibition of chemokine-like factor 1 improves bloodbrain barrier dysfunction in rats following focal cerebral ischemia

OBJECTIVE To investigate the role of chemokine-like factor 1(CKLF1),a novel C-C chemokine,on brain-blood barrier(BBB)integrity in rat focal cerebral ischemia and reperfusion model.METHODS Antibodies against CKLF1 was applied to the rightcerebral ventricle immediately after transient middle cerebral artery occlusion.Brain water content,Evans blue leakage and the expression of aquaporin-4(AQP-4),matrix metalloproteinase-9(MMP-9),zonula occludens-1(ZO-1)and occludin were measured.RESULTS After treatment with antiCKLF1 antibody,brain water content and Evans blue leakage in ipsilateral hemisphere were decreased in a dose-dependent manner at 24 h after reperfusion,but not changed in contralateral hemisphere.Anti-CKLF1 antibody reduced the expression of AQP-4 and MMP-9,and upregulated the expression of ZO-1 and Occludin.These results suggest that CKLF1 is involved in BBB disruption after reperfusion.CONCLUSION Inhibition of CKLF1 protects against cerebral ischemia by maintaining BBB integrity,possibly via inhibiting the expression of AQP-4 and MMP-9,and increasing the expression of tight junction protein.

Influence of hypoxia-inducible factor 1-alpha on neuronal apoptosis in a rat model of hypoxia-or hypoxia-ischemia-induced brain injury

BACKGROUND： In addition to neuroprotective genes, the targeted genes of hypoxia-inducible factor 1α （HIF-1α） include pro-apoptotic genes. However, the influence of HIF-1α on neuronal apoptosis in hypoxia-ischemia remains poorly understood. OBJECTIVE： To investigate the relationship between HIF-1α expression and neuronal apoptosis in hypoxia or hypoxia-ischemia brain injury and to determine the role of HIF-1α in regulating neuronal apoptosis. DESIGN, TIME AND SETTING： A randomized, controlled animal experiment was performed at the Laboratory of Children Neurology of Sichuan University between May 2006 and May 2007. MATERIALS： In situ cell death detected kit was provided by Roche, USA; rabbit anti-mouse HIF-1α polyclonal antibody was purchased from Santa Cruz Biotechnologies, USA; rabbit anti-mouse cleaved caspase-3 polyclonal antibody was purchased from Chemicon, USA. METHODS： A total of 36 Sprague Dawley rats aged 10 days were randomly assigned to 3 groups： sham-surgery, hypoxia, and hypoxia-ischemia, with 12 rats per group. The rats were treated at 3 time points： 4, 8, and 24 hours, with 4 rats per time point. In the hypoxia-ischemia group, the right common carotid artery was exposed and permanently ligated through a midline cervical incision. A 2.5-hour exposure to hypoxia （8% O2/92% N2） was used to induce hypoxia-ischemia injury. In the hypoxia group, rats were exposed to hypoxia without ligation of the common carotid artery. In the sham-surgery group, the common carotid artery was exposed without ligation or hypoxia. MAIN OUTCOME MEASURES： Histopathological changes, HIF-1α and activated caspase-3 protein expression, integrated optical density of positive cells, and apoptosis-positive cells. RESULTS： Hematoxylin and eosin staining showed that neuronal degeneration and edema was most prominent at 24 hours after hypoxia-ischemia. HIF-1α protein expression was significantly upregulated at 4 hours, peaked at 8 hours, and decreased at 24 hours after hypoxia or hypoxia-ischemia. HIF-1α protein expression was significant greater in the hypoxia and hypoxia-ischemia groups compared with the sham-surgery group （P 〈 0.01）. Activated caspase-3 protein expression began to increase at 4 and 8 hours following hypoxia or hypoxia-ischemia and was significantly upregulated at 24 hours. Activated caspase-3 protein expression remained at low levels in the sham controls compared with the hypoxia and hypoxia-ischemia groups （P〈 0.01）. TUNEL staining showed that the number of apoptotic cells significantly increased at 24 hours after hypoxia or hypoxia-ischemia. In addition, HIF-1α protein expression was greater in the hypoxia group compared with the hypoxia-ischemia group at the same time point （P 〈 0.05）. However, activated caspase-3 expression and the number of TUNEL-positive cells were less in the hypoxia group compared with the hypoxia-ischemia group at the same time point （P〈 0.05）. CONCLUSION： HIF-1α played a neuroprotective role following hypoxia-ischemia brain injury.