Effects of Carvedilol on Cardiomyocyte Apoptosis and Gene Expression In Vivo after Ischemia-Reperfusion in Rats

The effects of carvedilol on cardiomyocyte apoptosis and expression of bcl-2. bax genes following ischemia (0. 5 h) and reperfusion (48 h) in vivo and the possible biological mechanism of carvedilol inhibiting cardiomyocyte apoptosis were studied. The left anterior descending artery in Wistar rats were ligated to establish ischemia-reperfusion (I/R) models. The model animals were divided into two groups: I/R group, the model rats not subject to other treatments except ischemia-reperfusion (n= 8); carvedilol-treated group (n= 8), I/R model rats treated with carvedilol. Eight rats in the sham-operated group were subjected to only experimental open operation. The number of apoptotic cardiomyocyte was determined by TUNEL staining. Immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to detect the expression of bcl-2 and bax genes. Image processing system was used to quantitatively dispose the positive metric substances of both immuno-histochemistry and ISHH through the average optical density (OD) value. The results showed that the number of the apoptotic cells were 36. 18±9 (I/R group) . 0-1 (sham-operated group) and 9. 5± 3 (carvedilol-treated group) in each visual field respectively with the difference being very significant among the groups (P<0. 001). The OD values of bcl-2 protein in sham-operated group, I/R group and carvedilol-treated group were 0. 14±0. 01, 0. 08±0. 02 and 0. 15±0. 03, respectively. The OD values of bcl-2 mRNA in sham-operated group, I/R group and carvedilol-treated group were 0. 08± 0. 01, 0. 06±0. 01 and 0. 09±0. 01, respectively. There was no significant difference between carvedilol-treated group and I/R group (P>0. 05). The OD values of bax protein in I/R group, sham-operated and carvedilol-treated-treated group were 0. 13±0. 02, 0. 07±0. 01, 0. 06±0. 01, respectively. There was very significant difference between carvedilol-treated group and I/R group (P <0. 01). Bcl-2/bax ratio was 1. 07±0. 14 (I/R group), 1. 28±0. 16 (sham-operated group), 2. 5 ±0. 26 (carvedilol-treated group) respectively with the difference being very significant between carvedilol-treated group and I/R group (P<0. 05). It was indicated that carvedilol could inhibit cardiomyocyte apoptosis following ischemia and reperfusion, which was related to the increased bcl-2/ bax ratio due to inhibition of bax gene expression.

Picroside Ⅱ down-regulates matrix metalloproteinase-9 expression following cerebral ischemia/reperfusion injury in rats

Studies have shown that Picroside Ⅱ attenuates inflammatory reactions following brain ischemia through the inhibition of the TLR-4-NF-KB signal transduction pathway, and ameliorates cerebral edema through the reduction of aquaporin-4 expression. Matrix metalloproteinase-9 （MMP-9）, located downstream of the TLR-4-NF-KB signal transduction pathway, can degrade the neurovascular matrix, damage the blood-brain barrier to induce cerebral edema, and directly result in neuronal apoptosis and brain injury, Therefore, the present study further observed MMP-9 expression in the brain tissues of rats with cerebral ischemia/reperfusion injury following Picroside Ⅱ treatment. Results demonstrated that Picroside Ⅱ significantly reduced MMP-9 expression in ischemic brain tissues, as well as neuronal apoptosis and brain infarct volume, suggesting Picroside Ⅱ exhibits neuroprotection by down-regulating MMP-9 expression and inhibiting cell apoptosis.

Potential targets for protecting against hippocampal cell apoptosis after transient cerebral ischemiareperfusion injury in aged rats

Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial proteins in hippocampal cell apoptosis after transient cerebral ischemia-reperfusion injury in aged rats using a comparative proteomics strategy. Our exper-imental results show that the aged rat brain is sensitive to ischemia-reperfusion injury and that transient ischemia led to cell apoptosis in the hippocampus and changes in memory and cognition of aged rats. Differential proteomics analysis suggested that this phenomenon may be mediated by mitochondrial proteins associated with energy metabolism and apoptosis in aged rats. This study provides potential drug targets for the treatment of transient cerebral isch-emia-reperfusion injury.

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.

Transretinoic acid inhibits rats gastric epithelial dysplasia induced by N-methyi-N-nitro-N-nitrosoguanidine:influences on cell apoptosis and expression of its regulatory genes

INTRODUCTIONGastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach [1].In the stomach ,like any other segment of the gut ,it is defined as an unequivocal non-invasive epithelial change[2,3].The observation of gastric dysplasia as a cancerous lesion was recognized over a century ago ,but it is only after the advent of gastroscopy that its clinical significance has been stressed[4-7].

Expression of Arginyl-tRNA Synthetase in Rats with Focal Cerebral Ischemia

Aminoacyl-tRNA syntheses （AARS） can catalyze the adenosine triphosphate （ATP）-dependent acylation of their cognate tRNA（s） with a specific amino acid. They can be seen as an index to reflect the energy metabolic rate of ischemic brain cells in ischemic penumbra. This study ex- amined the relationship between arginyl-tRNA synthetase （ArgRS）, one of the AARS, and cerebral ischemia in rats. The model of middle cerebral artery occlusion （MCAO） was established in rats. The expression levels of ArgRS protein and mRNA were detected in rat brain tissues at different time points following MCAO by Western blotting and RT-PCR, respectively. The results showed that the MCAO model was successfully established. Western blotting and RT-PCR analysis revealed that the ArgRS protein and mRNA were expressed in brain cells in both ischemic and normal penumbra tissues. The expression levels of ArgRS protein and mRNA peaked at 6 h after MCAO and decreased gradually. At 24 h, the expression levels of ArgRs protein and mRNA in ischemic penumbral tissues were lower than those in normal tissues. The expression levels of ArgRS mRNA and protein in ischemic penumbra var- ied with ischemic time, suggesting that the energy metabolism of brain cells in penumbra changed dy- namically after ischemia to ensure the endogenous self-protection of the body. The brain oxygen supply should be improved as soon as possible, especially within 6-12 h after ischemia, so as to meet the de- mand for energy metabolism in ischemic penumbra and make sure the cell structure remains stable.

ARGININE VASOPRESSIN GENE EXPRESSION IN SUPRAOPTIC NUCLEUS AND PARAVENTRICULAR NUCLEUS OF HYPOTHALAMOUS FOLLOWING CEREBRAL ISCHEMIA AND REPERFUSION

Background. Our previous studies indicated that the increased arginine vasopressin(AVP) in ischemic brain regions of gerbils could exacerbate the ischemic brain edema. This experiments is further clarify the relation between AVP and cerebral ischemia at the molecular level. Methods. The contents of AVP, AVP mRNA, AVP immunoreactive(ir) neurons in supraoptic nucleus(SON) and paraventricular nucleus(PVN) after cerebral ischemia and reperfusion were respectively determined by radioimmunoassay(RIA), immunocytochemistry(ⅡC), situ hybridization and computed image pattern analysis. Results. The contents of AVP in SON, PVN were increased, and the AVP ir positive neurons in SON and PVN were also significantly increased as compared with the controls after ischemia and reperfusion. And there were very light staining of AVP ir positive neurons in the other brain areas such as suprachiasmatic nucleus (SC) and periventricular hypothalamic nucleus (PE), but these have no significant changes as compared with the controls. During different periods of cerebral ischemia (30～120 min) and reperfusion (30 min), AVP mRNA expression in SON and PVN were more markedly increased than the controls. Conclusions. The transcription of AVP gene elevated, then promoting synthesis and release of AVP in SON, PVN. Under the specific condition of cerebral ischemia and reperfusion, the activity and contents of central AVP increased abnormally is one of the important factors which causes ischemia brain damage.

Analysis of differentially expressed genes related to cerebral ischaemia in young rats based on the Gene Expression Omnibus database

BACKGROUND The incidence rate of cerebral infarction in young people is increasing day by day,the age of onset tends to be younger,and its internal pathogenesis and mechanism are very complicated,which leads to greater difficulties in treatment.Therefore,it is essential to analyze the key pathway that affects the onset of cerebral infarction in young people from the perspective of genetics.AIM To compare the differentially expressed genes in the brain tissue of young and aged rats with middle cerebral artery occlusion and to analyse their effect on the key signalling pathway involved in the development of cerebral ischaemia in young rats.METHODS The Gene Expression Omnibus 2R online analysis tool was used to analyse the differentially expressed genes in the GSE166162 dataset regarding the development of cerebral ischaemia in young and aged groups of rats.DAVID 6.8 software was further used to filter the differentially expressed genes.These genes were subjected to Gene Ontology(GO)function analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis to determine the key gene pathway that affects the occurrence of cerebral ischaemia in young rats.RESULTS Thirty-five differentially expressed genes(such as Igf2,Col1a2,and Sfrp1)were obtained;73 GO enrichment analysis pathways are mainly involved in biological processes such as drug response,amino acid stimulation response,blood vessel development,various signalling pathways,and enzyme regulation.They are involved in molecular functions such as drug binding,protein binding,dopamine binding,metal ion binding,and dopamine neurotransmitter receptor activity.KEGG pathway enrichment analysis showed a significantly enriched pathway:The cyclic adenosine monophosphate(c-AMP)signalling pathway.CONCLUSION The c-AMP signalling pathway might be the key pathway in the intervention of cerebral infarction in young people.

Inosine inhibits apoptosis and cytochrome C mRNA expression in rat neurons after cerebral ischemia/reperfusion

BACKGROUND: It has been demonstrated that adenosine can induce glial cell to release cytochrome C, enhance expression of apoptotic gene bax, inhibit anti-apoptotic gene bcl-2, and activate caspase-3 to apoptosis; Whereas inosine can inhibit neuronal apoptosis which is similar to bcl-2. OBJECTIVE: To observe the effects of inosine on neuronal apoptosis and expression of cytochrome C mRNA in rats after focal cerebral ischemia/reperfusion, and analyze the pathway of its neuroprotective effect. DESIGN: A randomised controlled animal trial. SETTINGS: Department of Neurology, Rongcheng Second People's Hospital; Department of Neurology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Sixty-eight rats, weighing 230-280 g and clean grade, were used. TdT-mediated dUTP-biotin nick end labeling (TUNEL) and cytochrome C mRNA in situ hybridization kits and DAB staining kit were purchased from Wuhan Boster Biological Co., Ltd.; Inosine injection [200 mg (2 mL) each] from Qingdao First Pharmaceutical Factory. METHODS: The experiment was accomplished in the animal experimental center in Tongji Medical College of Huazhong University of Science and Technology from December 2003 to June 2005. ① Sixty-four rats were made into focal ischemia by middle cerebral artery occlusion (MCAO) with a nylon monofilament suture. The successfully induced rats were assigned to inosine group (n =32) and model group (n =32) at random. Rats in the inosine group were intraperitoneally administrated with inosine in dose of 100 mg/kg preoperatively, twice a day, 7 days in all. The rats in the control group were injected with the same dose of saline solution by the similar way preoperatively. Each group was randomized into ischemia /reperfusion 2, 6, 12, 24 hours, 2, 3, 7 and 14 days subgroups consisted of 4 rats. The other 4 rats were taken as the sham-operated group, the rats were given the same treatment except for not introduced the filament into the external carotid artery stump, and brain tissue was removed at 2 hours of reperfusion. ② In situ hybridization was performed to examine the expression of cytochrome C mRNA while TUNEL staining was made to characterize apoptosis. ③ The t test was used to compare the difference of measurement data. MAIN OUTCOME MEASURES: ① Neuronal apoptosis in the different regions of the ischemic brain tissue; ② Expression of cytochrome C mRNA in the different regions at different time points after MCAO. RESULTS: All the 68 rats were involved in the analysis of results. ① Neuronal apoptosis: A small number of TUNEL-positive cells were detected in the sham-operated brain and non-ischemic brain. The number of apoptotic cells in the ischemic cortex peaked at 24 hours of reperfusion [(72.00±1.98) cells] and that in the striatum peaked at 2 days [(94.75±3.57) cells], then decreased to the level of sham-operated group at 14 days. Inosine could reduce apoptotic cells from 12 hours to 7 days of reperfusion as compared with the model group (t =6.19-26.67, P < 0.01). ② Cytochrome C mRNA expression: There was weak expression of cytochrome C mRNA in both sham-operated brain and contralateral brain. Cytochrome C was detected at 2 hours of reperfusion in ischemic brain [(25.75±3.50), (39.75±2.49) cells], and strongly increased to a peak at 12 hours and 24 hours of reperfusion in cortex and striatum [(122.50±6.69), (119.25±5.12) cells], respectively. Furthermore, inosine could significantly decrease cytochrome C expression in cortex at 12 hours to 14 days of reperfusion after ischemic reperfusion and that in striatum at 12 hours to 3 days (t =8.67-43.26, P < 0.01). CONCLUSION: Inosine can exert a neuroprotective effect by inhibiting apoptosis and cytochrome C mRNA expression.

Effect of calcitonin gene-related peptide and nerve growth factor on spatial learning and memory abilities of rats following focal cerebral ischemia/reperfusion

BACKGROUND: Calcitonin gene-related peptide (CGRP) and nerve growth actor (NGF) cam improve spatial learning and memory abilities of rats with cerebral ischemia/reperfusion; however, the effect of combination of them on relieving learning and memory injury following cerebral ischemia/reperfusion should be further studied. OBJECTIVE: To study the effects of exogenous CGRP and NGF on learning and memory abilities of rats with focal cerebral ischemia/reperfusion. DESIGN: Randomized controlled animal study. SETTING: Department of Neurosurgery, the Second Hospital of Xiamen; Department of Neurosurgery, the Second Affiliated Hospital of China Medical University; Department of Neurobiology, Basic Medical College of China Medical University. MATERIALS: A total of 30 healthy male SD rats, aged 8 weeks, of clean grade, weighing 250-300 g, were provided by Experimental Animal Department of China Medical University. All rats were randomly divided into sham-operation group, ischemia/reperfusion group and treatment group with 10 in each group. The main reagents were detailed as the follows: 100 g/L chloral hydrate, 0.5 mL CGRP (2 mg/L, Sigma Company, USA), and NGF (1× 106 U/L, 0.5 mL, Siweite Company, Dalian). METHODS: The experiment was carried out in the Department of Neurobiology, Basic Medical College of China Medical University from February to July 2005. Rat models of middle cerebral artery occlusion were established by method of occlusion, 2 hours after that rats were anesthetized and the thread was slightly drawn out for 10 mm under direct staring to perform reperfusion. Rats in the ischemia/reperfusion group received intraperitoneal injection of 1 mL saline via the abdomen at two hours later, while rats in the treatment group at 2 hours later received intraperitoneal injection of 2 mg/L CGRP (0.5 mL) and 1×106 U/L NGF (0.5 mL) once a day for 10 successive days. First administration was accomplished within 15 minutes after ischemia/reperfusion. Rats in the sham-operation group were separated of the vessels without occlusion or administration. The neural function was evaluated with Zea Longa 5-grade scale. Animals with the score of one, two and three points received Morris water-maze test to measure searching time on platform (omitting platform-escaping latency). Meanwhile, leaning and memory abilities of animals were reflected through testing times of passing through platform per minute. MAIN OUTCOME MEASURES: Experimental results of omitting platform-escaping latency and spatial probe. RESULTS: Three and two rats in the ischemia/reperfusion group and treatment group respectively were not in accordance with the criteria in the process, and the rest were involved in the final analysis. ① Comparisons of platform-escaping latency during Morris water-maze test in all the three groups: Ten days after modeling, the platform-escaping latency in the ischemia/reperfusion group was obviously longer than that in sham-operation group (P < 0.01), and was significantly shorter than that in the treatment group (P < 0.01). ② Comparisons of times of passing through platform in all the three groups: Times of passing through platform were remarkably less in the ischemia/reperfusion group than those in the sham-operation group [(1.79±0.39), (4.30±0.73) times/minute, P < 0.01], and those were markedly more in the treatment group than the ischemia/reperfusion group [(3.16±1.03), (1.79±0.39) times/minute, P < 0.01]. CONCLUSION: CGRP and NGF are capable of ameliorating the abilities of spatial learning and memory in MCAO rats, which indicates that CGRP and NGF can protect ischemic neurons.

Electro-acupuncture for STAT3 expression and nuclear translocation in hippocampal tissues of rats following cerebral ischemia/reperfusion

BACKGROUND: It has been found in recent years that STAT3 widely distributes in nervous system, including hippocampal CA1-3 region, dentate gyrus and cerebral neocortex, etc. Ischemic brain injury can cause the release of some cytokines and growth factors, while electro-acupuncture may have multi-level, multi-channel and multi-target protective and interventional effects on ischemic brain injury. OBJECTIVE: To observe the effects of electro-acupuncture on STAT3 expression and nuclear translocation in hippocampal CA1 region of rat models of brain ischemia/reperfusion. DESIGN: Randomized and controlled observation. SETTING: Staff Room of Acupuncture and Moxibustion, Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine; Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Seventy-two healthy SD rats, of clean degree and either gender, weighing (200±20) g, were provided by the Experimental Animal Center of Hubei College of Traditional Chinese Medicine. STAT3 monoclonal antibody was purchased from Santa Cruz Company, USA, and G-6805 electro-acupuncture instrument was purchased from Shanghai Medical Electronic Instruments Factory. METHODS: This experiment was carried out in the comprehensive laboratory of Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine between September 2005 and February 2006. Seventy-two rats were randomly divided into 4 groups: ① control group(n =6): Untouched. ② Sham-operation group (n =18): Artery was isolated, but without inserting thread bolt.③ Model group (n =24): Rat models of local brain ischemia/reperfusion were established with modified suture occlusion. ④Electro-acupuncture group (n =24): Dazhui and bilateral Neiguan points were selected for electro-acupuncture treatment. No. 28 acupuncture needle of 3.33 cm was used in the treatment. A G-6085 electro-acupuncture instrument with continuous wave, frequency of 120 times/min, intensity of 1 mA, 30 min/time, was used. Acupuncture was conducted firstly at ischemia/reperfusion 3 hours, then once every 12 hours. STAT3 positive nuclear translocation in hippocampal CA1 region of rats was observed with immunohistochemical method at 24, 48 and 72 hours after brain ishcemia/reperfusion, and then STAT3 positive cells were counted. MAIN OUTCOME MEASURES: STAT3 positive cells and nuclear translocation in hippocampal CA1 region of rats in each group. RESULTS: All the 72 rats were involved in the result analysis. ①In the control group and sham-operation group, STAT3 positive cells with light cytoplasm and nucleus were decreased , and nuclear translocation was not found. ② In the model group, STAT3 positive cells were mostly found in the cytoplasm of the hippocampal CA1 region at the ischemic side of rats after ischemia/reperfusion 24 hours. They were significantly more than those in the sham-operation group and control group [(18.00±2.68), (9.00±1.35), (8.00±1.22) cells/ mm2, P < 0.01], but cells with nuclear reaction were fewer; At ischemia/reperfusion 48 and 72 hours, STAT3 positive cells were increased, and they were significantly more than those of sham-operation group [(25.00±3.23), (35.00±3.52) cells/mm2, (13.00±1.93), (12.00±1.24) cells/mm2, P < 0.01]. Positive cells with nuclear reaction were found dark-stained. ③At ischemia/reperfusion 24, 48 and 72 hours, STAT3 positive cells were strongly expressed in hippocampal CA1 region at ischemic side of rats of electro-acupuncture group, and they were significantly more than those of model group [(25±3.52), (50±6.31), (75±8.09) cells/mm2, P < 0.01]. STAT3 positive cells were gradually enhanced with time, and considerable STAT3 nuclear positive reaction cells were found. CONCLUSION: Electro-acupuncture can activate STAT3 protein expression in hippocampal tissue of rats with local brain ischemia/reperfusion, promote STAT3 nuclear translocation and function its neuroprotective effect.

Effects of phycocyanin on apoptosis and expression of superoxide dismutase in cerebral ischemia reperfusion injury

BACKGROUND ： The application of exogenous antioxidant is always the focus in the prevention and treatment of cerebral ischemia. Phycocyanin has the effects against oxidation and inflammation, but its role in the pathophysiological process of cerebral ischemia reperfusion injury still needs further investigation. OBJECTIVE： To observe the effects of phycocyanin on the expression of superoxide dismutase （SOD） apoptosis and form of the nerve cells in rats after cerebral ischemia reperfusion injury. DESIGN： A randomized control animal experiment SETTING ： Institute of Cerebrovascular Disease, Medical School Hospital of Qingdao University MATERIALS： Fifty-two healthy adult male Wistar rats of clean degree, weighing 220-260 g, were used. Phycocyanin was provided by the Institute of Oceanology, Chinese Academy of Sciences. METHODS： The experiments were carried out in Shangdong Key Laboratory for Prevention and Treatment of Brain Diseases from May to December 2005. ① All the rats were divided into three groups according to the method of random number table： sham-operated group （n=4）, control group （n=24） and treatment group （n=24）. Models of middle cerebral artery occlusion/reperfusion （MCAO/R） were established by the introduction of thread through external and internal carotid arteries in the control group and treatment group. After 1-hour ischemia and 2-hour reperfusion, rats in the treatment group were administrated with gastric perfusion of phy- cocyanin suspension （0.1 mg/g）, and those in the control group were given saline of the same volume, and no treatment was given to the rats in the sham-operated group. ②The samples were removed and observed at ischemia for 1 hour and reperfusion for 6 and 12 hours and 1, 3, 7 and 14 days respectively in the control group and treatment group, 4 rats for each time point, and those were removed at 1 day postoperatively in the sham-operated group. Forms of the nerve cells were observed with toluidine blue staining. Apoptosis after cerebral ischemia reperfusion was detected with TUNEL technique. SOD expression was detected with immunohistochemical technique.③ The intergroup difference was compared with the ttest. MAIN OUTCOME MEASURES： The apoptosis of the nerve cells and SOD expression were mainly observed in each group. RESULTS： Finally, 52 rats were involved in the analysis of results. ① Number of apoptotic cells： In the sham-operated group, a few apoptotic cells could be observed in brain tissue. The apoptotic cells at each time point in the control group and treatment group were obviously more than those in the sham-operated group （P 〈 0.05）. In the treatment group, the numbers of apoptotic cells at 12 hours, 1 and 3 days after reperfusion were significantly fewer than those in the control group, and those at 6 hours, 7 and 14 days were similar to those in the control group. ② Number of SOD positive cells： In the sham-operated group, there was weak expression of SOD in brain tissue, and the positive cells were extremely few, the positive cells at each time point were significantly more in the control group and treatment group than in the sham-operated group （P 〈 0.05）. In the treatment group, the numbers of positive cells at 6 and 12 hours, 1 and 3 days after reperfusion were significantly fewer than those in the control group, and those at 7-14 days were similar to those in the control group. ③ Cellular forms： In the control group, the karyopyknosis occurred in the nerve cells, which were irregularly distributed, nucleolus disappeared, and some scattered cell fragments were observed. The forms of the nerve cells in the treatment group were generally normal. CONCLUSION ： Phycocyanin plays a neuroprotective role in cerebral ischemia reperfusion injury by activating the SOD expression and inhibiting apoptosis.

Let-7a gene knockdown protects against cerebral ischemia/reperfusion injury

The micro RNA（mi RNA） let-7 was one of the first mi RNAs to be discovered, and is highly conserved and widely expressed among species. let-7 expression increases in brain tissue after cerebral ischemia/reperfusion injury; however, no studies have reported let-7 effects on nerve injury after cerebral ischemia/reperfusion injury. To investigate the effects of let-7 gene knockdown on cerebral ischemia/reperfusion injury, we established a rat model of cerebral ischemia/reperfusion injury. Quantitative reverse transcription-polymerase chain reaction demonstrated that 12 hours after cerebral ischemia/reperfusion injury, let-7 expression was up-regulated, peaked at 24 hours, and was still higher than that in control rats after 72 hours. Let-7 gene knockdown in rats suppressed microglial activation and inflammatory factor release, reduced neuronal apoptosis and infarct volume in brain tissue after cerebral ischemia/reperfusion injury. Western blot assays and luciferase assays revealed that mitogen-activated protein kinase phosphatase-1（MKP1） is a direct target of let-7. Let-7 enhanced phosphorylated p38 mitogen-activated protein kinase（MAPK） and c-Jun N-terminal kinase（JNK） expression by down-regulating MKP1. These findings suggest that knockdown of let-7 inhibited the activation of p38 MAPK and JNK signaling pathways by up-regulating MKP1 expression, reduced apoptosis and the inflammatory reaction, and exerted a neuroprotective effect following cerebral ischemia/reperfusion injury.

CHANGES OF ENDOTHELIN－1 GENE EXPRESSION IN RAT BRAINS DURING ISCHEMIA AND ISCHEMIC REPERFUSION

Objective. The experiment was designed to study the association of cerebral ischemia and reperfusion with endothelin- 1 (ET- 1) gene expression of rat brains and time-dependent changes of ET- 1 gene expression during cerebral ischemia.Materials and methods. Thirty- three male SD rats were divided into dot blot hybridization(n = 27) and in silu hybridization groups(n= 6). The focal cerebral ischemia and reperfusion models were made with suture embolism of middle cerebral artery. Dot blot hybridization groups were redivided into control and ischemic subgroups (ischemia for 0. 5 , 1 , 1. 5 , 3 , 6 , 12 , 24 , 48 and 72 h respectively). In situ hybridization groups were redivided into ischemia and reperfusion groups. After 24 h ischemia and 24 h reperfusion,ET1 gene expressions were investigated with in situ hybridization and the resuhs were analyzed with IBAS 2000 Image Analysis System.Results. Dot blot hybridization showed that ET-1 mRNA of cerebral cortex and caudate- putamen was increased at 6 h of ischemia and reached peak at 24 h (3. 9 and 3. 7 fold respectively) ,and at 72 h of ischemia it remained at high levels(3. 5 and 2. 1 fold respectively). In silu hybridization showed that the levels of ET- 1 mRNA of cerebral cortex and caudate-putamen were also markedly increased both in 24 h ischemia and 24 h reperfusion groups (P<0. 01 , P<0. 05 respectively) .Conclusions. ET-1 gene expression in focal ischemic brain tissue were markedly and progressively increased during cerebral ischemia and reperfusion and downregulation of ET- 1 gene expression may be a new approach to the treatment of ischemic cerebrovascular diseases.

Effects of L-Tetrahydropalmatine on the Expressions of bcl-2 and bax in Rat after Acute Global Cerebral Ischemia and Reperfusion

To investigate the effects of L-Tetrahydropalmatine (L-THP) on the expressions of bcl-2, bax and neuronal apoptosis after cerebral ischemia and reperfusion, 60 Wistars rats were randomly divided into 3 groups: sham-operation group (group S, n = 20), ischemic-reperfusion group treated with saline (group I, n=20) and ischemia-reperfusion group treated with L-THP (group T, n=20) .The rat model of global cerebral ischemia and reperfusion was induced by Pulsinelli's four-vessel occlusion method. The expression of bcl-2 and bax mRNA was detected by in situ hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). The number of apoptotic neurons was examined by terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method. Compared with group S, the expression of bcl-2 and bax mRNA in group I was increased significantly (P<0.01), and the number of apoptotic neurons increased either (P< 0.01). After L-THP treatment, the expression of bcl-2 mRNA was up-regulated (P<0.01) and that of bax mRNA was down-regulated (P<0.01); the number of apoptotic neurons was decreased (P<0.01). Our results indicated that bcl-2 may suppress apoptosis and bax promote apoptosis after cerebral ischemia and reperfusion. L-THP could ameliorate cerebral ischemia and reperfusion damage by reducing the apoptosis through regulating bcl-2 and bax.

Effect of adenovirus-mediated gene transfer of Olig1 on oligodendrocyte differentiation and remyelination in a rat model of focal cerebral ischemia

BACKGROUND： The transcription factor Oligl is required for oligodendrocyte maturation and demyelinated lesion repair, and is a key regulator of myelinogenesis following ischemia. OBJECTIVE： To examine the efficacy of intraventricular injection of a recombinant adenovirus-expressing Oligl gene （Ad5-Oligl-eGFP） on oligodendrocyte maturation and myelin repair following focal cerebral ischemia. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Neurology, Beijing Friendship Hospital Affiliated to Capital Medical University from January 2007 to March 2008. MATERIALS： Adenovirus and a recombinant adenovirus containing Oiigl gene （Ad5-Oligl） were provided by Vector Gene Technology, China. METHODS： All 50 rats were induced by middle cerebral artery occlusion. A total of 46 rats were successfully induced and were subsequently randomly assigned to a adenovirus （Ad5） group and recombinant adenovirus-expression Oligl gene （Ad5-Oligl） group, with 23 rats per group. One day after middle cerebral artery occlusion, either Ad5-Oligl-eGFP or Ad5-eGFP （10 μL, 2.3 ×10^11/mL） was injected into the lateral ventricle on the ischemic hemisphere. MAIN OUTCOME MEASURES： Adenovirus-mediated Oligl gene expression in vitro and in vivo was measured by reverse transcription-polymerase chain reaction and immunofluorescence, respectively. Myelin basic protein （MBP） levels were evaluated by Western Blot, immunostaining, and electron microscopy. RESULTS： Exogenous Oligl expression was measured at the periventricular zone of the lateral ventricle 1 day after Ad5-Oligl injection. In the Ad5-Oligl-treated group, MBP protein levels and average intensity of MBP-immunoreactivity （-ir） increased 28 days after middle cerebral artery occlusion, compared with the control group （P 〈 0.01, P 〈 0.05）. Furthermore, myelinated axonal numbers markedly increased following Ad5-Oligl treatment. CONCLUSION： The present data suggested that Ad5-Oligl gene therapy increased MBP expression and the number of remyelinating axons following cerebral ischemia.

Effect of cluster needling at scalp acupoints on differential protein expression in rat brain tissue after acute focal cerebral ischemia

Objective:To explore the function of cluster needling at scalp points therapy on regulating differential protein's expression at different time points in middle cerebral artery occlusion(MCAO)model rats.Methods:Fifty-four rats were divided into three groups randomly and 18 rats in each group.The groups respectively were the model group(group M,n=18),cluster needling at scalp points group(group C,n=18),false operation group(group F,n=18).Each group was then assigned in three subgroups,including 24-h,7-day,and 14-day subgroups.Six rats in each subgroup.Acupuncture at Baihui(GV20)and 2 points beside Baihui,which was 3 e4 mm away from the midline.Longa score was used to evaluated neurological effects.Proteomics methods were used to identify differentially expression proteins with a standard of fold change greater than 1.5 and P<.05 at different times.Results:1.Nerve function scoring:The nerve function scores at 7 and 14 days decreased in group C,which showed better neural function than group M(P<.05).2.Fold change in proteins:Group M showed932 differentially expressed proteins compared with group F,and among them,414 proteins showed significant changes in expression after acupuncture.The expression levels of Cdc42 and GFAP were increased,and Mag,Shank2,and MBP levels were decreased.In the Gene Ontology analysis,the cellular component consisted of the terms cytoplasm,cytoskeleton,lysosome,and plasma membrane.The main related biological processes were cellecell signaling,protein transport,aging,and cell adhesion.Many synaptic and metabolic pathways were found by KEGG analysis.Conclusion:Cluster needling at scalp acupoints can improve the nerve function score and improve dyskinesia in MCAO model rats.Cluster needling at scalp acupoints can regulate the expression of 414 proteins,including Cdc42,GFAP,Mag,Shank2,and MBP,which are related to cerebral ischemia.The differential proteins are major concentration in cytoplasm,cytoskeleton,lysosomes,and plasma membrane,participate in cellecell signaling,protein transport,aging,and cell adhesion,and act through multiple synaptic and metabolic pathways to exert their biological functions.

MicroRNAs: a novel promising therapeutic target for cerebral ischemia/reperfusion injury?

To determine the molecular mechanism of cerebral ischemia/reperfusion injury, we examined the micro RNA（mi RNA） expression profile in rat cortex after focal cerebral ischemia/reperfusion injury using mi RNA microarrays and bioinformatic tools to systematically analyze Gene Ontology（GO） function classifications, as well as the signaling pathways of genes targeted by these differentially expressed mi RNAs. Our results show significantly changed mi RNA expression profiles in the reperfusion period after focal cerebral ischemia, with a total of 15 mi RNAs up-regulated and 44 mi RNAs down-regulated. Target genes of these differentially expressed mi RNAs were mainly involved in metabolic and cellular processes, which were identified as hub nodes of a mi RNA-GO-network. The most correlated pathways included D-glutamine and D-glutamate metabolism, the renin-angiotensin system, peroxisomes, the PPAR signaling pathway, SNARE interactions in vesicular transport, and the calcium signaling pathway. Our study suggests that mi RNAs play an important role in the pathological process of cerebral ischemia/reperfusion injury. Understanding mi RNA expression and function may shed light on the molecular mechanism of cerebral ischemia/reperfusion injury.

Effect of basic fibroblast growth factor and danshen on bcl-2 and p53 mRNA expression in the brain of rats exposed to repeated, high, positive acceleration (+Gz)

BACKGROUND： Both animal experiments and clinical studies have shown that basic fibroblast growth factor （bFGF） and danshen （Salvia miltiorrhiza） can exhibit protective effects on ischemia-reperfusion cerebral injury. OBJECTIVE： To test whether bFGF and danshen can protect cerebral injury induced by exposure to repeated, high, positive acceleration （＋Gz） in an animal model and to analyze the possible mechanisms. DESIGN, TIME AND SETTING： Randomized controlled animal study. The experiment was performed at the Research Center for Molecular Biology, Air-force General Hospital of Chinese PLA from April to August 2000. MATERIALS： A total of 20 clean grade, healthy, Sprague Dawley rats of both genders, weighing （200 ± 15） g, were provided by our experimental animal center. Rats were randomly divided into 5 groups： the control group, ＋Gz exposure group, bFGF group, danshen group, and saline group, with 4 animals per group. bFGF （Beijing Bailuyuan Biotechnology Co. Ltd.） and danshen solution （Shanghai Zhongxi Pharmaceutical Co. Ltd.） were used. METHODS： All rats were fixed on a rotary arm of a centrifugal apparatus （2 m in radius） with their heads oriented towards the center of the apparatus. Except for rats in the control group, the value of ＋Gz exposure was ＋14 Gz with an acceleration rate of 1.5 G/s. The peak force lasted for 45 seconds. ＋Gz exposure was performed three times with intervals of 30 minutes. Rats in the control group received the same ＋Gz procedure, but the G value was ＋1 Gz. Rats in bFGF group and danshen group were intraperitoneally injected with 100 μg/kg bFGF or 15 g/kg danshen solution, respectively, at 30 minutes prior to centrifugation and immediately after centrifugation. Rats in saline group were injected with the same volume of saline. Six hours after exposure, rats were decapitated. One hemisphere was preserved in liquid nitrogen for RNA extraction and the other was processed for apoptosis detection. MAIN OUTCOME MEASURES： mRNA levels of bcl-2 and p53 were measured by semi-quantitative reverse-transcription polymerase chain reaction. Apoptotic cell death was detected by terminal deoxynuleotidyl transferase-mediated dUTP nick end labeling. RESULTS： Changes in mRNA expression of bcl-2 and p53 and apoptotic cells were observed in rat brain six hours after repeated ＋Gz exposures, bFGF and danshen were able block the changes of bcl-2 and p53 expression and inhibit apoptotic cell death. CONCLUSION： The data suggest that apoptosis and changes in bcl-2 and p53 expression in the rat brain can be induced by repeated ＋Gz exposures. Apoptosis is, therefore, one of the molecular mechanisms of brain damage induced by repeated ＋Gz exposures, bFGF and danshen were of the equal potency in preventing brain injury induced by repeated ＋Gz exposures.

EFFECT OF RADIX SALVIAE MILTIORRHIZAE ON THE GENE EXPRESSION OF NITRIC OXIDE SYNTHASE IN ISCHEMIC RAT BRAINS

The effect of Radix Salviae Miltiorrhizae (RSM) on the gene expression of nitric oxide synthase (NOS) in rat brains during ischemia was studied with in situ hybridization and the results were analyzed with IBAS 2000 Image Analysis System. It was found that NOS gene expression of cerebral cortex and caudate-putamen was markedly increased in 24 hours in ischemia group (P