Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on o...Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on oxygen glucose deprivation-induced hypoxia inducible factor-1α expression.In this study,we hypothesized that DL-3-n-butylphthalide can protect against oxygen glucose deprivation-induced injury of newborn rat brain microvascular endothelial cells by means of upregulating hypoxia inducible factor-1α expression.MTT assay and Hoechst staining results showed that DL-3-n-butylphthalide protected brain microvascular endothelial cells against oxygen glucose deprivation-induced injury in a dose-dependent manner.Western blot and immunofluorescent staining results further confirmed that the protective effect was related to upregulation of hypoxia inducible factor-1α.Real-time RT-PCR reaction results showed that DL-3-n-butylphthalide reduced apoptosis by inhibiting downregulation of pro-apoptotic gene caspase-3 mRNA expression and upregulation of apoptosis-executive protease bcl-2 mRNA expression;however,DL-3-n-butylphthalide had no protective effects on brain microvascular endothelial cells after knockdown of hypoxia inducible factor-1α by small interfering RNA.These findings suggest that DL-3-n-butylphthalide can protect brain microvascular endothelial cells against oxygen glucose deprivation-induced injury by upregulating bcl-2 expression and downregulating caspase-3 expression though hypoxia inducible factor-1α pathway.展开更多
Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with ne...Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.展开更多
BACKGROUND: Excessive alcohol consumption can result in multiple organ injury, of which alcoholic liver disease (ALD) is the most common. With economic development and improvement of living standards, the incidence of...BACKGROUND: Excessive alcohol consumption can result in multiple organ injury, of which alcoholic liver disease (ALD) is the most common. With economic development and improvement of living standards, the incidence of diseases caused by alcohol abuse has been increasing in China, although its pathogenesis remains obscure. The aim of this study was to investigate the role of hypoxia in chronic ALD. METHODS: Twenty-eight male Sprague-Dawley rats were randomized into a control group (n=12) with a normal history and an experimental group (n=16) fed with 10 ml/ kg of 56% (vol/vol) ethanol once per day by gastric lavage for 24 weeks. At 24 weeks, blood samples were collected and then the rats were killed. Liver samples were frozen at -80 ℃ and used for RT-PCR; other liver samples were obtained for immunohistochemical staining. RESULTS: When the period of alcohol consumption increased, the positive rate of expression of hypoxia- inducible factor-1 alpha (HIF-1α) mRNA was more significantly elevated in the liver of the alcohol group than in the control group (P≤0.05). The HIF-1α protein located in the cytoplasm was seldom expressed in the control group, but significantly in the alcohol group (P≤0.01). CONCLUSION: HIF-1α mRNA expression was activated by ethanol-induced injury in this study, suggesting that hypoxia is involved in the underlying mechanism of ALD.展开更多
AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B(PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia. METHODS: Esophageal carcinoma cell lin...AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B(PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia. METHODS: Esophageal carcinoma cell lines Eca109 and TE13 were cultured under hypoxia environment, and the protein, m RNA and activity levels of hypoxia inducible factor-1 alpha(HIF-1α), glucose transporter 1, hexokinase-Ⅱ, phosphofructokinase 2 and lactate dehydrogenase-A were determined. Supernatant lactic acid concentrations were also detected. The PI3K/AKT signaling pathway was then inhibited with wortmannin, and the effects of hypoxia on the expression or activities of HIF-1α, associated glycolytic enzymes and lactic acid concentrations were observed. Esophageal carcinoma cells were then transfected with interference plasmid with HIF-1α-targeting si RNA to assess impact of the high expression of HIF-1α on glycolysis.RESULTS: HIF-1α is highly expressed in the esophageal carcinoma cell lines tested, and with decreasing levels of oxygen, the expression of HIF-1α and the associated glycolytic enzymes and the extracellular lactic acid concentration were enhanced in the esophageal carcinoma cell lines Eca109 and TE13. In both normoxia and hypoxic conditions, the level of glycolytic enzymesand the secretion of lactic acid were both reduced by wortmannin. The expression and activities of glycolytic enzymes and the lactic acid concentration in cells were reduced by inhibiting HIF-1α, especially the decreasing level of glycolysis was significant under hypoxic conditions.CONCLUSION: The PI3K/AKT pathway and HIF-1α are both involved in the process of glycolysis in esophageal cancer cells.展开更多
In this study, a rat vascular dementia model was established by permanent bilateral common carotid arterial occlusion. Rats were intraperitoneally injected with puerarin 3 days before modeling, for 45 successive days....In this study, a rat vascular dementia model was established by permanent bilateral common carotid arterial occlusion. Rats were intraperitoneally injected with puerarin 3 days before modeling, for 45 successive days. Results demonstrated that in treated animals hippocampal structures were clear, nerve cells arranged neatly, and cytoplasm was rich in Nissl bodies. The number of cells positive for hypoxia inducible factor-1 alpha, erythropoietin and endothelial nitric oxide synthase was reduced; and the learning and memory abilities of rats were significantly improved. Our experimental findings indicate that puerarin can significantly improve learning and memory in a vascular dementia model, and that the underlying mechanism may be associated with the regulation of the expression of hypoxia inducible factor-1 alpha.展开更多
Hypoxia-inducible factor-1 alpha（HIF-1α） plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a m...Hypoxia-inducible factor-1 alpha（HIF-1α） plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a meta-analysis was implemented to further understand the prognostic role of HIF-1α in lung cancer. The relationship between HIF-1α and the clinicopathological characteristics and prognosis of lung cancer were investigated by a meta-analysis. Pub Med and Embase were searched from their inception to January 2015 for observational studies. Fixed-effects or random-effects meta-analyses were used to calculate odds ratios and 95% confidence intervals of different comparisons. A total of 20 studies met the criteria. The results showed that HIF-1α expression in lung cancer tissues was significantly higher than that in normal lung tissues. Expression of HIF-1α in patients with squamous cell carcinoma was significantly higher than that of patients with adenocarcinomas. Similarly, non-small cell lung cancer（NSCLC） patients had higher HIF-1α expression than small cell lung cancer（SCLC） patients. Moreover, lymph node metastasized tissues had higher HIF-1α expression than non-lymph node metastasized tissues. A high level HIF-1α expression was well correlated with the expression of vascular endothelial growth factor and epidermal growth factor receptor in the NSCLC. Notably, NSCLC or SCLC patients with positive HIF-1α expression in tumor tissues had lower overall survival rate than patients with negative HIF-1α expression. It was suggested that HIF-1α expression may be a prognostic biomarker and a potential therapeutic target for lung cancer.展开更多
BACKGROUND： Hypoxia inducible factor-1 alpha （HIF-1 （x） and erythropoietin（EPO）, possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tol...BACKGROUND： Hypoxia inducible factor-1 alpha （HIF-1 （x） and erythropoietin（EPO）, possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tolerance （IT）. OBJECTIVE：To observe the neuroprotective effect of cerebral ischemic preconditioning（IPC） of rats, and the expression and mechanism of HIF-1α and target gene erythropoietin in the brain tissue following the formation of cerebral IT. DESIGN ： A randomized and controlled observation SETTING： Department of Neurology, the Affiliated Hospital of Medical College, Qingdao University MATERIALS： Totally 84 enrolled adult healthy male Wistar rats of clean grade, weighing 250 to 300 g, were provided by the Animal Experimental Department, Tongji Medical College of Huazhong University of Science and Technology. Ready-to-use SABC reagent kit and rabbit anti-rat HIF-1α monoclonal antibody were purchased from Boshide Bioengineering Co.Ltd （Wuhan）; Rabbit anti-rat EPO monoclonal antibody was purchased from Santa Cruz Company （USA）. METHODS： This experiment was carried out in the Department of Anatomy, Medical College, Qingdao University during March 2005 to March 2006. ① The 84 rats were divided into 3 groups by a lot： IPC group （n=40）, sham-operation group （n=40） and control group （n=4）. In the IPC group, middle cerebral artery was occluded for 2 hours respectively on the 1^st, 3^rd, 7^th, 14^th and 21^st days of the reperfusion following 10-minute preischemia was made using a modified middle cerebral artery second suture method from Zea-Longa. The rats were sacrificed 22 hours after reperfusion in the end of middle cerebral artery occlusion （MCAO）. That was to say, after 10-minute preischemia, suture was exited to the extemal carotid artery and embedded subcutaneously. Middle cerebral artery was occluded again to form the second reperfusion at the set time point after reperfusion. Twenty-two hours later, rats were sacrificed; In the sham-operation group,the preischemia was substituted by sham-operation（only common carotid artery and crotch were exposed, and MCAO by suture was omitted）, and the other procedures were the same as those in the IPC group. In the control group, rats were given sham-operation twice at an interval of one day, and they were sacrificed 24 hours after the second sham-operation. ② Brain tissue was taken from the rats in each group. Cerebral infarction area of each layer was measured with TTC staining, and total cerebral infarction volume （The total cerebral infarction area of each layerxinterspace ） was calculated. After brain tissue was stained by haematoxylin-esoin （HE）, the form of nerve cells was observed under an optical microscope, and the expressions of HIF-1α（and EPO protein in the brain tissue were detected with immunohistochemical method. MAIN OUTCOME MEASURES： ①Cerebral infarction volume;②form of nerve cell; ③ the expression of HIF-1α and EPO protein in the brain tissue. RESULTS：Totally 84 rats were enrolled in the experiment. The dead rats were randomly supplied during the experiment, and finally 84 rats entered the stage of result analysis. ① Detection of cerebral infarction volume of rats in each group： Cerebral infarction volume in the IPC group was significantly smaller than that in the sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively [（161.2±6.9） mm^3 vs （219.9±11.2） mm^3, （134.9±9.0） mm^3 vs （218.6±13.0） mm^3, （142.9±13.7） mm^3 vs （221.3±14.2） mm^3, t=-8.924, 10.587,7.947, P〈 0.01]. ② Observation of nerve cell form of brain tissue： HE staining showed that the ischemic degree, range and cerebral edema degree of IPC group were significantly milder than those of sham-operation group. ③ The expressions of HIF-1α and EPO protein in cerebral cortex and hippocampus ： The expression of HIF-1αof IPC group was significantly higher than that of sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively （125.93±3.79 vs 117.65±5.60, 140.63±4.64 vs 119.33±4.26, 131.15±2.74 vs 107.60±3.89, t=2.449, 6.763,9.899,P 〈 0.05-0.01）. The expression of EPO of IPC group was significantly higher than that of sham-operation group on the 3^rd and 7^th days after perfusion respectively （141.68±3.29 vs 126.33±4.51, 138.88±2.59 vs 125.58±6.18,t=5.499,3.970, P〈 0.05）. CONCLUSION ： ①IPC can protect the never cells in rat brain and the best time to onset of cerebral IT induced by IPC is 1 to 7 days after reperfusion. ② Neuroprotective effect of cerebral IT might be related to the expression of HIF-1α and its target gene EPO.展开更多
AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for pati...AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for patients with gastric cancer(Gc).METHODS Hypoxia is a critical factor that shapes the Gc microenvironment. In previous reports, we have demonstrated that P4 HB is a potential target of HIF-1α. In the present study, gene expression profiling interactive analysis(GEPIA) was used to analyze the relationship between P4 HB and hypoxia-associated genes. To this end, 428 Gc tissue samples were used to analyze the expression of HIF-1α and P4 HB via immunohistochemical staining. Patient samples were classified as having weak-expression or over-expression both in terms of HIF-1α and P4 HB. Correlations between biomarkers and clinicopathological factors were analyzed to predict survival. RESULTS P4 HB demonstrated a positive correlation with hypoxiaassociated genes(P < 0.05). HIF-1α and P4 HB overexpression have a significant correlation with TNM staging(χ2 = 23.32, P = 0.00; χ2 = 65.64, P = 0.00) and peritoneum cavity metastasis(χ2 = 12.67, P = 0.00; χ2 = 39.29, P = 0.00). In univariate analysis, patients with a high HIF-1α expression trend had a shorter disease-free survival(DFS: 44.80 mo vs 22.06 mo) and overall survival(OS: 49.58 mo vs 39.92 mo). P4 HB overexpression reflected similar results: patients with over-expression of P4 HB had a shorter survival time than those with weak-expression(DFS: 48.03 mo vs 29.64 mo, OS: 52.48 mo vs 36.87 mo). Furthermore, HIF-1α is also a clinicopathological predictor of dismal prognosis according to multivariate analysis(DFS, 95%c I: 0.52-0.88, P < 0.00; OS, 95%c I: 0.50-0.85, P < 0.00). However, P4 HB was meaningful in DFS(95%c I: 0.58-1.00, P < 0.05) but not in OS(95%c I: 0.72-1.23, P > 0.05).CONCLUSION Overexpression of HIF-1α and P4 HB is associated with poor prognosis in patients with Gc. Thus, these genes may be potential prognostic biomarker candidates in GC.展开更多
We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis fac...We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.展开更多
OBJECTIVE:To evaluate the effect of Fuzi Lizhong decoction(附子理中汤)on intestinal flora,serum inflammatory factors,and hypoxia inducible factor-1α(HIF-1α)in patients with colorectal cancer associated with spleen a...OBJECTIVE:To evaluate the effect of Fuzi Lizhong decoction(附子理中汤)on intestinal flora,serum inflammatory factors,and hypoxia inducible factor-1α(HIF-1α)in patients with colorectal cancer associated with spleen and kidney Yang deficiency.METHODS:A total of 100 patients diagnosed with advanced colorectal cancer were randomly divided into two groups:a control group(CON,50)and a Traditional Chinese Medicine(TCM)group(n=50).The control group received treatment with the Capecitabine+Oxaliplatin(CAPEOX)regimen,while the TCM group received the same regimen along with Fuzi Lizhong decoction for six weeks.Changes in intestinal flora were assessed before and after six weeks in both groups.Serum markers,including HIF-1α,vascular endothelial growth factor(VEGF),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α),were measured using enzyme-linked immunosorbent assay.Adverse reactions,clinical efficacy,and TCM syndrome efficacy were also monitored.RESULTS:After six weeks,the levels of Lactobacillus and Bifidobacterium were significantly higher,while the levels of Enterobacter and Enterococcus were significantly lower in the TCM group compared to the control group(P<0.05).Serum levels of HIF-1α,VEGF,IL-6,and TNF-αwere also significantly reduced in the TCM group compared to the control group(P<0.05).Additionally,the incidence of adverse reactions was lower,and the clinical efficacy was higher in the TCM group compared to the control group(P<0.05).CONCLUSION:Fuzi Lizhong decoction effectively improves intestinal microbiota composition,reduces inflammatory factors and HIF-1αexpression,alleviates chemotherapy-related adverse reactions,enhances clinical efficacy,and may inhibit tumor growth in patients with colorectal cancer.展开更多
BACKGROUND Hypoxia-inducible factor 1α(HIF-1α)plays a crucial role in the prognosis of breast cancer,but the current evidence remains inconclusive.AIM To provide comprehensive evidence about the correlation of alter...BACKGROUND Hypoxia-inducible factor 1α(HIF-1α)plays a crucial role in the prognosis of breast cancer,but the current evidence remains inconclusive.AIM To provide comprehensive evidence about the correlation of altered HIF-1αexpression with overall survival(OS)and disease-free survival(DFS)in breast cancer patients.METHODS A systematic search was conducted in PubMed,Embase,and Web of Science databases to collect relevant articles that were published before April 8,2024.A meta-analysis was used to assess the impact of altered HIF-1αexpression on the OS and DFS of breast cancer patients.Subgroup and sensitivity analyses were also performed in this meta-analysis.RESULTS This meta-analysis included 40 studies.The average percentage of breast cancer patients with high HIF-1αexpression was 39.6%.The overall meta-analysis results demonstrated that high HIF-1αexpression is strongly linked to poor outcomes in patients of breast cancer.Compared with low HIF-1αexpression,the overall hazard ratio for OS in patients with high HIF-1αexpression was 1.47[95%confidence interval(CI):1.29-1.69],and the overall hazard ratio for DFS was 1.82(95%CI:1.56-2.12).Furthermore,both OS[1.18(95%CI:1.01-1.38)]and DFS[1.79(95%CI:1.03-3.11)]were markedly shorter in triple-negative breast cancer cases with high HIF-1αexpression.Subgroup analysis revealed that the antibody used to detect HIF-1αexpression affected only the correlation linking HIF-1αexpression to DFS in breast cancer patients(P=0.0004).Furthermore,the sensitivity analysis demonstrates that the overall conclusions of the meta-analysis were unaffected by the removal of individual studies.CONCLUSION Compared to patients with low HIF-1αexpression,those with high expression level had shorter OS and DFS.However,the prognostic significance of high HIF-1αexpression varies across molecularly stratified breast cancer cohorts needs to be further elucidated.展开更多
BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its...BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.展开更多
Objective: To investigate the specific mechanism of hypoxia-inducible factor 1 alpha (HIF-1α) in the regulation of human sperm apoptosis, and to provide a new theoretical reference and scientific basis for the diagno...Objective: To investigate the specific mechanism of hypoxia-inducible factor 1 alpha (HIF-1α) in the regulation of human sperm apoptosis, and to provide a new theoretical reference and scientific basis for the diagnosis and treatment of asthenospermia and other related conditions. Methods: Semen samples were categorized into the normal group and asthenospermia group based on sperm motility criteria. HIF-1α interfering agent cobalt chloride (CoCl2) and guanylate cyclase activator (Lificiguat, YC-1) were added respectively, with a control group established accordingly. Sperm motility (using anterior viability rate as an index), apoptosis level, ATP level, mitochondrial membrane potential, and reactive oxygen species (ROS) level were measured. The expression levels of HIF-1α, p-PI3K, and Bcl-2 in the samples were analyzed using Western blotting. Results: Following CoCl2 treatment, there was a significant increase in sperm apoptosis compared to the normal control group (12.51% ± 2.50% VS 11.15% ± 2.42%);additionally, sperm motility (45.34% ± 3.37% VS 51.36% ± 11.68%), ATP production (11.51 ± 2.87 nM/µL VS 14.99 ± 2.83 nM/µL), ROS levels, and mitochondrial membrane potential all decreased significantly (all P α and p-PI3K increased significantly while Bcl-2 expression decreased (all P α in the YC-1 treatment group were decreased, and the expression level of Bcl-2 was increased (all P α can influence human sperm apoptosis and motility through the PI3K signaling pathway.展开更多
BACKGROUND Hypoxia in oral cancer promotes tumoral invasion by inducing epithelial-mesenchymal transition,leading to aggressive tumor progression.AIM To characterize the expression of hypoxia-inducible factor 1-alpha(...BACKGROUND Hypoxia in oral cancer promotes tumoral invasion by inducing epithelial-mesenchymal transition,leading to aggressive tumor progression.AIM To characterize the expression of hypoxia-inducible factor 1-alpha(HIF-1α)at the invasive tumor front(ITF)in comparison to tumor islands(TI)in oral squamous cell carcinoma(OSCC)and to explore its relationship with E-cadherin and Vimentin expression.METHODS Thirty-eight cases of OSCC and five cases of normal oral mucosa(NOM)were included in this study.The ITF was identified based on the region and immune expression of AE1/AE3.Immunohistochemistry was performed to assess the expression of HIF-1α,Vimentin,and E-cadherin.The immunostaining was analyzed using an immunoreactive score,and the results were illustrated using immunofluorescence.RESULTS HIF-1αexpression was significantly higher in the TI region compared to the ITF region(P=0.0134).Additionally,a significant difference was observed between TI and NOM(P=0.0115).In the ITF regions,HIF-1αexpression showed a significant correlation with Vimentin expression,with higher levels of HIF-1αassociated with increased Vimentin expression(P=0.017).CONCLUSION Based on the results of this study,HIF-1αappears to play a distinct role in OSCC tumor progression,underscoring the importance of exploring hypoxia-driven changes in cellular phenotype at the ITF of OSCC.Further research is needed to better understand their impact on OSCC prognosis.展开更多
Objective MicroRNA-1(miR-1)aggravates myocardial ischemia–reperfusion(I/R)injury,whereas insulin-like growth factor-1(IGF-1)maintains cardiomyocyte homeostasis.In this study,the aim is to investigate whether miR-1 ca...Objective MicroRNA-1(miR-1)aggravates myocardial ischemia–reperfusion(I/R)injury,whereas insulin-like growth factor-1(IGF-1)maintains cardiomyocyte homeostasis.In this study,the aim is to investigate whether miR-1 can exacerbate I/R injury through the regulation of IGF-1.Methods The infarct area,lactate dehydrogenase,miR-1 level,and apoptosis level were examined in the Langendorff isolated rat I/R model.The hypoxia–reoxygenation model of rat cardiacmyocytes and H9c2 cells were developed to determine the levels of miR-1,IGF-1 mRNA,and IGF-1 protein.Furthermore,the dual-luciferase assay was used to verify the relationship between miR-1 and IGF-1.Results Overexpression of miR-1 increased the level of apoptosis and decreased the IGF-1 expression.However,inhibition of miR-1 expression decreased the level of apoptosis,alleviated the degree of injury,and increased the IGF-1 expression.Overexpression of IGF-1 also reduced the degree of cellular damage and level of apoptosis caused by the overexpression of miR-1.When IGF-1 was knocked down,myocardial cells displayed more severe damage and a higher apoptosis level,even with decreased levels of miR-1.Conclusion miR-1 promotes apoptosis and aggravates I/R injury by downregulating IGF-1.展开更多
OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-...OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-inducible factor-1α(HIF-1α)and pyruvate kinase M2(PKM2)signaling pathway,along with the glycolysis metabolism pathway.METHODS:The animals were divided into the following groups:Model,Control,dapagliflozin,SHT low-dose,SHT medium-dose,and SHT high-dose.We assessed 24-hour urine protein(24 h-UTP)levels,urinary albuminto-creatinine ratio,and regularly monitored fasting blood glucose during the treatment period.After treatment,we examined renal tissue structure,renal function(urea nitrogen,uric acid,creatinine,cystatin C,β2-microglobulin),and glycolysis in renal macrophages.Additionally,we observed macrophage polarization in renal tissue and measured inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10,monocyte chemoattractant protein-1)to assess the immunoinflammatory status of the renal tissue.Finally,we investigated the expression of the HIF-1α/PKM2 signaling pathway in macrophages to explore its role in the glycolysis process.RESULTS:SHT shows a beneficial effect in treating DKD by reducing 24 h-UTP,regulating blood glucose levels,improving renal tissue structure,protecting renal function,inhibiting macrophage glycolysis,reducing macrophage transformation to the M1 state,and suppressing the expression of the HIF-1α/PKM2 signaling pathway.CONCLUSION:SHT may exert renoprotective effects by inhibiting macrophage glycolysis via the HIF-1α/PKM2 signaling pathway.This inhibition decreases macrophage M1 polarization and reduces immunoinflammatory injury in the renal tissue of DKD mice.展开更多
BACKGROUND Hepatic ischemia reperfusion(HIR)injury is a major complication affecting various major liver surgeries,including liver transplantation.Aprepitant(APRE),a neurokinin-1 receptor antagonist,is commonly used a...BACKGROUND Hepatic ischemia reperfusion(HIR)injury is a major complication affecting various major liver surgeries,including liver transplantation.Aprepitant(APRE),a neurokinin-1 receptor antagonist,is commonly used as an antiemetic to prevent chemotherapy-induced nausea and vomiting.AIM To assess the potential protective effect of APRE against HIR-induced liver injury via targeting the nucleotide-binding oligomerization domain-,leucine-rich repeat-,and pyrin domain-containing receptor 3/interleukin(IL)-1beta signaling pathway.METHODS Six groups of adult male Wistar albino rats were divided as follows:Sham group,Sham/APRE10 group(APRE 10 mg/kg),HIR group,HIR/APRE5 group(APRE 5 mg/kg),HIR/APRE10 group(APRE 10 mg/kg),and HIR/APRE20 group(APRE 20 mg/kg).Serum alanine transaminase,aspartate transaminase,liver malondialdehyde,total antioxidant capacity levels,as well as IL-6,sirtuin 1(Sirt1),caspase-3,cleaved caspase-3,and tumor necrosis factor alpha biomarkers,were evaluated.Hepatic specimens were examined histopathologically and immunohistochemically for nuclear factor erythroid-2-related factor 2(Nrf2)immunoexpression.RESULTS HIR resulted in hepatic damage,as evidenced by histopathological changes and a significant increase in serum alanine transaminase,aspartate transaminase,hepatic malondialdehyde,caspase-3,and tumor necrosis factor alpha levels.Additionally,there were significant increases in hepatic total antioxidant capacity and reductions in IL-6 and cleaved caspase-3 protein levels,as demonstrated by Western blot analysis,along with enhanced immunoexpression of Sirt1 and Nrf2.APRE has significantly reduced various parameters of oxidative stress,inflammation,and apoptosis,and a significant increase in liver Nrf2 immunoexpression,leading to a significant improvement in the histopathological changes.CONCLUSION In conclusion,targeting the Sirt1/Nrf2 signaling pathway,as demonstrated by APRE in our model,could present a promising therapeutic target to protect against HIR-induced liver injury during major liver surgeries.展开更多
BACKGROUND： Hypoxia-inducible factor-1 （HIF-1） accumulates under conditions of hypoxia. HIF-1α target genes have pleiotropic effects on neurogenesis, neuroprotection and angiogenesis in the brain. OBJECTIVE： To i...BACKGROUND： Hypoxia-inducible factor-1 （HIF-1） accumulates under conditions of hypoxia. HIF-1α target genes have pleiotropic effects on neurogenesis, neuroprotection and angiogenesis in the brain. OBJECTIVE： To investigate whether a recombinant adenovirus carrying HIF-1α can increase the expression of HIF-I a in vivo and thus promote angiogenesis and neurogenesis in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING： The randomized, controlled experiment was performed at the Department of Neurobiology, Third Military Medical University of Chinese PLA from September 2006 to October 2007. MATERIALS： 68 healthy adult male Sprague-Dawley （SD） rats, weighing 230-250 g, were used. HIF-I a antibody was purchased from Wuhan Boster Company. Vascular endothelial growth factor （VEGF） antibody was purchased from Santa Cruz Biotech Company. METHODS： All 68 rats were induced with a transient middle cerebral artery occlusion （MCAO）, according to the method of intra-luminal vascular occlusion. 54 rats, in which MCAO was successfully induced, were randomly divided into adenovirus （Ad） group and recombinant adenovirus with HIF-1α gene （Ad-HIF-1α ） group （27 rats for each group）. Rats were injected with 10 μL Ad （Ad group） or Ad-HIF-1α （Ad-HIF-1α group） into the lateral ventricle, 1 day after MCAO induction. MAIN OUTCOME MEASURES： Reverse transcription polymerase chain reaction was used to measure the expression of HIF-1α and of VEGF. Immunohistochemistry was used to detect the localization of HIF-1α, VEGF and factor Ⅷ in ischemic penumbra. Rat newborn nerve cells were labeled with 5-bromodeoxyuridine （BrdU） after ischemia. BrdU/neurofilament 200 （NF200） and BrdU/glial fibrillary acidic protein （GFAP） double labeled immunofluorescent histochemistry was used to identify the differentiation of newborn cells. Neurological function was evaluated using the modified neurological severity score （NSS）. RESULTS： Compared with Ad, Ad-HIF-1α enhanced the expression of HIF-1α and VEGF （P 〈 0.01）. The numbers of factor VIII, BrdU, BrdU/NF200 and BrdU/GFAP positive cells were increased significantly （P 〈 0.01） in the Ad-HIF-I a group compared to the Ad group. Levels of HIF-1α and VEGF mRNA in the Ad-HIF-1α group were enhanced compared with those in the Ad group. NSS scores of the Ad-HIF-1α group were superior to those of the Ad group at days 7, 14, 21, and 28 after MCAO （P 〈 0.05）. CONCLUSION： HIF-1α gene therapy can increase angiogenesis and neurogenesis, and thus improve neurological function following cerebral ischemia in rats.展开更多
BACKGROUND： Numerous studies have shown that transient ischemic preconditioning induces cerebral ischemic tolerance. However, the underlying mechanisms of endogenous protection following ischemic preconditioning rema...BACKGROUND： Numerous studies have shown that transient ischemic preconditioning induces cerebral ischemic tolerance. However, the underlying mechanisms of endogenous protection following ischemic preconditioning remain unclear. OBJECTIVE： To dynamically measure erythropoietin and hypoxia-inducible factor-1α （HIF-1α） mRNA and protein expression at various times following preconditioning, and to investigate effects of erythropoietin and HIF-1α on cerebral ischemic tolerance in a model of focal ischemia/reperfusion established using the twice suture method. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Institute of Anatomy, Medical College, Qingdao University, China from March 2006 to March 2007. MATERIALS： Rabbit anti-rat HIF-1α monoclonal antibody and biotinylated goat anti-rabbit IgG （Boster, China）, rabbit anti-rat erythropoietin monoclonal antibody （Santa Cruz Biotechnology, USA）, and one-step RT-PCR kit （Qiagen, Germany） were used in this study. METHODS： A total of 99 healthy, male, Wistar rats were randomly assigned to three groups： sham surgery （n = 9）, non-ischemic preconditioning （n = 45）, and ischemic preconditioning （n = 45）. In the ischemic preconditioning group, rat models of pre-ischemia-reperfusion-ischemia-reperfusion were established by occluding the left middle cerebral artery using the twice suture method. In the non-ischemic preconditioning group, pre-ischemia was replaced by sham surgery. Subsequently, the ischemic preconditioning and non-ischemic preconditioning groups were equally divided into five subgroups according to time of first reperfusion, including 1-, 3-, 7-, 14-, and 21-day subgroups. The sham surgery group received the sham surgery twice. MAIN OUTCOME MEASURES： HIF-la and erythropoietin protein expression was measured in the cerebral cortex, corpus striatum, and hippocampus of the ischemic hemisphere. HIF-1α and erythropoietin mRNA expression were determined in the frontal and parietal cortex of the ischemic hemisphere. RESULTS： （1） Intergroup comparison： compared with the non-ischemic preconditioning group, HIF-1α protein expression significantly increased in the rat cerebral cortex, corpus striatum, and hippocampus in the ischemic hemisphere at 1,3, and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05 or P 〈 0.01）. Erythropoietin protein expression significantly increased in the cerebral cortex, corpus striatum, and hippocampus, as well as HIF-1α and erythropoietin mRNA expression in the frontal and parietal cortex in the ischemic hemisphere, at 3 and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05）. （2） Temporal expression： HIF-1α protein expression in the rat cerebral cortex, corpus striatum, and hippocampus, as well as HIF-la mRNA expression in the frontal and parietal cortex, in the ischemic hemisphere increased at 3 days, and gradually decreased from 7 days following reperfusion in the ischemic preconditioning group. Temporal erythropoietin protein and mRNA expression was consistent with HIF-1α protein expression. （3） Correlation： erythropoietin mRNA expression positively correlated with HIF-1α mRNA expression （r= 0.737, P 〈 0.01）. CONCLUSION： Ischemic preconditioning induced cerebral ischemic tolerance. Pre-ischemiainduced increase in endogenous HIF-1αexpression, as well as its target gene erythropoietin, participated in the formation of cerebral ischemic tolerance.展开更多
基金supported by the National Natural Science Foundation of China,No.30471917 and 30770766
文摘Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on oxygen glucose deprivation-induced hypoxia inducible factor-1α expression.In this study,we hypothesized that DL-3-n-butylphthalide can protect against oxygen glucose deprivation-induced injury of newborn rat brain microvascular endothelial cells by means of upregulating hypoxia inducible factor-1α expression.MTT assay and Hoechst staining results showed that DL-3-n-butylphthalide protected brain microvascular endothelial cells against oxygen glucose deprivation-induced injury in a dose-dependent manner.Western blot and immunofluorescent staining results further confirmed that the protective effect was related to upregulation of hypoxia inducible factor-1α.Real-time RT-PCR reaction results showed that DL-3-n-butylphthalide reduced apoptosis by inhibiting downregulation of pro-apoptotic gene caspase-3 mRNA expression and upregulation of apoptosis-executive protease bcl-2 mRNA expression;however,DL-3-n-butylphthalide had no protective effects on brain microvascular endothelial cells after knockdown of hypoxia inducible factor-1α by small interfering RNA.These findings suggest that DL-3-n-butylphthalide can protect brain microvascular endothelial cells against oxygen glucose deprivation-induced injury by upregulating bcl-2 expression and downregulating caspase-3 expression though hypoxia inducible factor-1α pathway.
基金supported by grants from VA merit awards(BX3401 and RX2090)
文摘Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.
文摘BACKGROUND: Excessive alcohol consumption can result in multiple organ injury, of which alcoholic liver disease (ALD) is the most common. With economic development and improvement of living standards, the incidence of diseases caused by alcohol abuse has been increasing in China, although its pathogenesis remains obscure. The aim of this study was to investigate the role of hypoxia in chronic ALD. METHODS: Twenty-eight male Sprague-Dawley rats were randomized into a control group (n=12) with a normal history and an experimental group (n=16) fed with 10 ml/ kg of 56% (vol/vol) ethanol once per day by gastric lavage for 24 weeks. At 24 weeks, blood samples were collected and then the rats were killed. Liver samples were frozen at -80 ℃ and used for RT-PCR; other liver samples were obtained for immunohistochemical staining. RESULTS: When the period of alcohol consumption increased, the positive rate of expression of hypoxia- inducible factor-1 alpha (HIF-1α) mRNA was more significantly elevated in the liver of the alcohol group than in the control group (P≤0.05). The HIF-1α protein located in the cytoplasm was seldom expressed in the control group, but significantly in the alcohol group (P≤0.01). CONCLUSION: HIF-1α mRNA expression was activated by ethanol-induced injury in this study, suggesting that hypoxia is involved in the underlying mechanism of ALD.
基金Supported by the National Natural Science Foundation of China,No.30800511
文摘AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B(PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia. METHODS: Esophageal carcinoma cell lines Eca109 and TE13 were cultured under hypoxia environment, and the protein, m RNA and activity levels of hypoxia inducible factor-1 alpha(HIF-1α), glucose transporter 1, hexokinase-Ⅱ, phosphofructokinase 2 and lactate dehydrogenase-A were determined. Supernatant lactic acid concentrations were also detected. The PI3K/AKT signaling pathway was then inhibited with wortmannin, and the effects of hypoxia on the expression or activities of HIF-1α, associated glycolytic enzymes and lactic acid concentrations were observed. Esophageal carcinoma cells were then transfected with interference plasmid with HIF-1α-targeting si RNA to assess impact of the high expression of HIF-1α on glycolysis.RESULTS: HIF-1α is highly expressed in the esophageal carcinoma cell lines tested, and with decreasing levels of oxygen, the expression of HIF-1α and the associated glycolytic enzymes and the extracellular lactic acid concentration were enhanced in the esophageal carcinoma cell lines Eca109 and TE13. In both normoxia and hypoxic conditions, the level of glycolytic enzymesand the secretion of lactic acid were both reduced by wortmannin. The expression and activities of glycolytic enzymes and the lactic acid concentration in cells were reduced by inhibiting HIF-1α, especially the decreasing level of glycolysis was significant under hypoxic conditions.CONCLUSION: The PI3K/AKT pathway and HIF-1α are both involved in the process of glycolysis in esophageal cancer cells.
文摘In this study, a rat vascular dementia model was established by permanent bilateral common carotid arterial occlusion. Rats were intraperitoneally injected with puerarin 3 days before modeling, for 45 successive days. Results demonstrated that in treated animals hippocampal structures were clear, nerve cells arranged neatly, and cytoplasm was rich in Nissl bodies. The number of cells positive for hypoxia inducible factor-1 alpha, erythropoietin and endothelial nitric oxide synthase was reduced; and the learning and memory abilities of rats were significantly improved. Our experimental findings indicate that puerarin can significantly improve learning and memory in a vascular dementia model, and that the underlying mechanism may be associated with the regulation of the expression of hypoxia inducible factor-1 alpha.
文摘Hypoxia-inducible factor-1 alpha（HIF-1α） plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a meta-analysis was implemented to further understand the prognostic role of HIF-1α in lung cancer. The relationship between HIF-1α and the clinicopathological characteristics and prognosis of lung cancer were investigated by a meta-analysis. Pub Med and Embase were searched from their inception to January 2015 for observational studies. Fixed-effects or random-effects meta-analyses were used to calculate odds ratios and 95% confidence intervals of different comparisons. A total of 20 studies met the criteria. The results showed that HIF-1α expression in lung cancer tissues was significantly higher than that in normal lung tissues. Expression of HIF-1α in patients with squamous cell carcinoma was significantly higher than that of patients with adenocarcinomas. Similarly, non-small cell lung cancer（NSCLC） patients had higher HIF-1α expression than small cell lung cancer（SCLC） patients. Moreover, lymph node metastasized tissues had higher HIF-1α expression than non-lymph node metastasized tissues. A high level HIF-1α expression was well correlated with the expression of vascular endothelial growth factor and epidermal growth factor receptor in the NSCLC. Notably, NSCLC or SCLC patients with positive HIF-1α expression in tumor tissues had lower overall survival rate than patients with negative HIF-1α expression. It was suggested that HIF-1α expression may be a prognostic biomarker and a potential therapeutic target for lung cancer.
基金the Scientific andTechnological DevelopmentProgram of Qingdao City, No.No.05-1-NS-73
文摘BACKGROUND： Hypoxia inducible factor-1 alpha （HIF-1 （x） and erythropoietin（EPO）, possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tolerance （IT）. OBJECTIVE：To observe the neuroprotective effect of cerebral ischemic preconditioning（IPC） of rats, and the expression and mechanism of HIF-1α and target gene erythropoietin in the brain tissue following the formation of cerebral IT. DESIGN ： A randomized and controlled observation SETTING： Department of Neurology, the Affiliated Hospital of Medical College, Qingdao University MATERIALS： Totally 84 enrolled adult healthy male Wistar rats of clean grade, weighing 250 to 300 g, were provided by the Animal Experimental Department, Tongji Medical College of Huazhong University of Science and Technology. Ready-to-use SABC reagent kit and rabbit anti-rat HIF-1α monoclonal antibody were purchased from Boshide Bioengineering Co.Ltd （Wuhan）; Rabbit anti-rat EPO monoclonal antibody was purchased from Santa Cruz Company （USA）. METHODS： This experiment was carried out in the Department of Anatomy, Medical College, Qingdao University during March 2005 to March 2006. ① The 84 rats were divided into 3 groups by a lot： IPC group （n=40）, sham-operation group （n=40） and control group （n=4）. In the IPC group, middle cerebral artery was occluded for 2 hours respectively on the 1^st, 3^rd, 7^th, 14^th and 21^st days of the reperfusion following 10-minute preischemia was made using a modified middle cerebral artery second suture method from Zea-Longa. The rats were sacrificed 22 hours after reperfusion in the end of middle cerebral artery occlusion （MCAO）. That was to say, after 10-minute preischemia, suture was exited to the extemal carotid artery and embedded subcutaneously. Middle cerebral artery was occluded again to form the second reperfusion at the set time point after reperfusion. Twenty-two hours later, rats were sacrificed; In the sham-operation group,the preischemia was substituted by sham-operation（only common carotid artery and crotch were exposed, and MCAO by suture was omitted）, and the other procedures were the same as those in the IPC group. In the control group, rats were given sham-operation twice at an interval of one day, and they were sacrificed 24 hours after the second sham-operation. ② Brain tissue was taken from the rats in each group. Cerebral infarction area of each layer was measured with TTC staining, and total cerebral infarction volume （The total cerebral infarction area of each layerxinterspace ） was calculated. After brain tissue was stained by haematoxylin-esoin （HE）, the form of nerve cells was observed under an optical microscope, and the expressions of HIF-1α（and EPO protein in the brain tissue were detected with immunohistochemical method. MAIN OUTCOME MEASURES： ①Cerebral infarction volume;②form of nerve cell; ③ the expression of HIF-1α and EPO protein in the brain tissue. RESULTS：Totally 84 rats were enrolled in the experiment. The dead rats were randomly supplied during the experiment, and finally 84 rats entered the stage of result analysis. ① Detection of cerebral infarction volume of rats in each group： Cerebral infarction volume in the IPC group was significantly smaller than that in the sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively [（161.2±6.9） mm^3 vs （219.9±11.2） mm^3, （134.9±9.0） mm^3 vs （218.6±13.0） mm^3, （142.9±13.7） mm^3 vs （221.3±14.2） mm^3, t=-8.924, 10.587,7.947, P〈 0.01]. ② Observation of nerve cell form of brain tissue： HE staining showed that the ischemic degree, range and cerebral edema degree of IPC group were significantly milder than those of sham-operation group. ③ The expressions of HIF-1α and EPO protein in cerebral cortex and hippocampus ： The expression of HIF-1αof IPC group was significantly higher than that of sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively （125.93±3.79 vs 117.65±5.60, 140.63±4.64 vs 119.33±4.26, 131.15±2.74 vs 107.60±3.89, t=2.449, 6.763,9.899,P 〈 0.05-0.01）. The expression of EPO of IPC group was significantly higher than that of sham-operation group on the 3^rd and 7^th days after perfusion respectively （141.68±3.29 vs 126.33±4.51, 138.88±2.59 vs 125.58±6.18,t=5.499,3.970, P〈 0.05）. CONCLUSION ： ①IPC can protect the never cells in rat brain and the best time to onset of cerebral IT induced by IPC is 1 to 7 days after reperfusion. ② Neuroprotective effect of cerebral IT might be related to the expression of HIF-1α and its target gene EPO.
基金Supported by Liaoning S and T Project,No.2015020269Doctor fund of Liaoning Province Cancer Hospital and Institute,No.Z1410
文摘AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for patients with gastric cancer(Gc).METHODS Hypoxia is a critical factor that shapes the Gc microenvironment. In previous reports, we have demonstrated that P4 HB is a potential target of HIF-1α. In the present study, gene expression profiling interactive analysis(GEPIA) was used to analyze the relationship between P4 HB and hypoxia-associated genes. To this end, 428 Gc tissue samples were used to analyze the expression of HIF-1α and P4 HB via immunohistochemical staining. Patient samples were classified as having weak-expression or over-expression both in terms of HIF-1α and P4 HB. Correlations between biomarkers and clinicopathological factors were analyzed to predict survival. RESULTS P4 HB demonstrated a positive correlation with hypoxiaassociated genes(P < 0.05). HIF-1α and P4 HB overexpression have a significant correlation with TNM staging(χ2 = 23.32, P = 0.00; χ2 = 65.64, P = 0.00) and peritoneum cavity metastasis(χ2 = 12.67, P = 0.00; χ2 = 39.29, P = 0.00). In univariate analysis, patients with a high HIF-1α expression trend had a shorter disease-free survival(DFS: 44.80 mo vs 22.06 mo) and overall survival(OS: 49.58 mo vs 39.92 mo). P4 HB overexpression reflected similar results: patients with over-expression of P4 HB had a shorter survival time than those with weak-expression(DFS: 48.03 mo vs 29.64 mo, OS: 52.48 mo vs 36.87 mo). Furthermore, HIF-1α is also a clinicopathological predictor of dismal prognosis according to multivariate analysis(DFS, 95%c I: 0.52-0.88, P < 0.00; OS, 95%c I: 0.50-0.85, P < 0.00). However, P4 HB was meaningful in DFS(95%c I: 0.58-1.00, P < 0.05) but not in OS(95%c I: 0.72-1.23, P > 0.05).CONCLUSION Overexpression of HIF-1α and P4 HB is associated with poor prognosis in patients with Gc. Thus, these genes may be potential prognostic biomarker candidates in GC.
基金a grant from the Science and Technology Department of Jilin Province,No. 200705172
文摘We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.
基金Supported by the Guangxi Natural Science Foundation“Controllable Synthesis of Ordered Mesoporous Seafoam-Loaded g-C3N4 Gomposites and Their Mechanism of Adsorption-Photocatalytic Degradation of Antidepressants in Water Bodies”(2017GXNSFBA198216)the Open Fund for the Director of Guangxi Key Laboratory of Spatial Information and Geographic Information“Geographic Spatial Analysis of Regional Urinary Tract Stone Disease”(19-185-10-04)。
文摘OBJECTIVE:To evaluate the effect of Fuzi Lizhong decoction(附子理中汤)on intestinal flora,serum inflammatory factors,and hypoxia inducible factor-1α(HIF-1α)in patients with colorectal cancer associated with spleen and kidney Yang deficiency.METHODS:A total of 100 patients diagnosed with advanced colorectal cancer were randomly divided into two groups:a control group(CON,50)and a Traditional Chinese Medicine(TCM)group(n=50).The control group received treatment with the Capecitabine+Oxaliplatin(CAPEOX)regimen,while the TCM group received the same regimen along with Fuzi Lizhong decoction for six weeks.Changes in intestinal flora were assessed before and after six weeks in both groups.Serum markers,including HIF-1α,vascular endothelial growth factor(VEGF),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α),were measured using enzyme-linked immunosorbent assay.Adverse reactions,clinical efficacy,and TCM syndrome efficacy were also monitored.RESULTS:After six weeks,the levels of Lactobacillus and Bifidobacterium were significantly higher,while the levels of Enterobacter and Enterococcus were significantly lower in the TCM group compared to the control group(P<0.05).Serum levels of HIF-1α,VEGF,IL-6,and TNF-αwere also significantly reduced in the TCM group compared to the control group(P<0.05).Additionally,the incidence of adverse reactions was lower,and the clinical efficacy was higher in the TCM group compared to the control group(P<0.05).CONCLUSION:Fuzi Lizhong decoction effectively improves intestinal microbiota composition,reduces inflammatory factors and HIF-1αexpression,alleviates chemotherapy-related adverse reactions,enhances clinical efficacy,and may inhibit tumor growth in patients with colorectal cancer.
基金Supported by the Henan Province Medical Science and Technology Tackling Plan Joint Construction Project,No.LHGJ20220684Zhengzhou University Tianjian Advanced Biomedical Laboratory Funding Project,No.BS20240101.
文摘BACKGROUND Hypoxia-inducible factor 1α(HIF-1α)plays a crucial role in the prognosis of breast cancer,but the current evidence remains inconclusive.AIM To provide comprehensive evidence about the correlation of altered HIF-1αexpression with overall survival(OS)and disease-free survival(DFS)in breast cancer patients.METHODS A systematic search was conducted in PubMed,Embase,and Web of Science databases to collect relevant articles that were published before April 8,2024.A meta-analysis was used to assess the impact of altered HIF-1αexpression on the OS and DFS of breast cancer patients.Subgroup and sensitivity analyses were also performed in this meta-analysis.RESULTS This meta-analysis included 40 studies.The average percentage of breast cancer patients with high HIF-1αexpression was 39.6%.The overall meta-analysis results demonstrated that high HIF-1αexpression is strongly linked to poor outcomes in patients of breast cancer.Compared with low HIF-1αexpression,the overall hazard ratio for OS in patients with high HIF-1αexpression was 1.47[95%confidence interval(CI):1.29-1.69],and the overall hazard ratio for DFS was 1.82(95%CI:1.56-2.12).Furthermore,both OS[1.18(95%CI:1.01-1.38)]and DFS[1.79(95%CI:1.03-3.11)]were markedly shorter in triple-negative breast cancer cases with high HIF-1αexpression.Subgroup analysis revealed that the antibody used to detect HIF-1αexpression affected only the correlation linking HIF-1αexpression to DFS in breast cancer patients(P=0.0004).Furthermore,the sensitivity analysis demonstrates that the overall conclusions of the meta-analysis were unaffected by the removal of individual studies.CONCLUSION Compared to patients with low HIF-1αexpression,those with high expression level had shorter OS and DFS.However,the prognostic significance of high HIF-1αexpression varies across molecularly stratified breast cancer cohorts needs to be further elucidated.
基金the National Natural Science Foundation of China,No.30671041the National Basic Research Program of China(973 Program),No. 2005CB623902
文摘BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.
文摘Objective: To investigate the specific mechanism of hypoxia-inducible factor 1 alpha (HIF-1α) in the regulation of human sperm apoptosis, and to provide a new theoretical reference and scientific basis for the diagnosis and treatment of asthenospermia and other related conditions. Methods: Semen samples were categorized into the normal group and asthenospermia group based on sperm motility criteria. HIF-1α interfering agent cobalt chloride (CoCl2) and guanylate cyclase activator (Lificiguat, YC-1) were added respectively, with a control group established accordingly. Sperm motility (using anterior viability rate as an index), apoptosis level, ATP level, mitochondrial membrane potential, and reactive oxygen species (ROS) level were measured. The expression levels of HIF-1α, p-PI3K, and Bcl-2 in the samples were analyzed using Western blotting. Results: Following CoCl2 treatment, there was a significant increase in sperm apoptosis compared to the normal control group (12.51% ± 2.50% VS 11.15% ± 2.42%);additionally, sperm motility (45.34% ± 3.37% VS 51.36% ± 11.68%), ATP production (11.51 ± 2.87 nM/µL VS 14.99 ± 2.83 nM/µL), ROS levels, and mitochondrial membrane potential all decreased significantly (all P α and p-PI3K increased significantly while Bcl-2 expression decreased (all P α in the YC-1 treatment group were decreased, and the expression level of Bcl-2 was increased (all P α can influence human sperm apoptosis and motility through the PI3K signaling pathway.
基金Supported by Comisión Sectorial de Investigación Científica(CSIC-Research Group 88180)The Agencia Nacional de Investigación e Innovación/Sistema Nacional de Investigadores(ANII/SNI)The Programa de Desarrollo de las Ciencias Básicas(PEDECIBA),Uruguay.
文摘BACKGROUND Hypoxia in oral cancer promotes tumoral invasion by inducing epithelial-mesenchymal transition,leading to aggressive tumor progression.AIM To characterize the expression of hypoxia-inducible factor 1-alpha(HIF-1α)at the invasive tumor front(ITF)in comparison to tumor islands(TI)in oral squamous cell carcinoma(OSCC)and to explore its relationship with E-cadherin and Vimentin expression.METHODS Thirty-eight cases of OSCC and five cases of normal oral mucosa(NOM)were included in this study.The ITF was identified based on the region and immune expression of AE1/AE3.Immunohistochemistry was performed to assess the expression of HIF-1α,Vimentin,and E-cadherin.The immunostaining was analyzed using an immunoreactive score,and the results were illustrated using immunofluorescence.RESULTS HIF-1αexpression was significantly higher in the TI region compared to the ITF region(P=0.0134).Additionally,a significant difference was observed between TI and NOM(P=0.0115).In the ITF regions,HIF-1αexpression showed a significant correlation with Vimentin expression,with higher levels of HIF-1αassociated with increased Vimentin expression(P=0.017).CONCLUSION Based on the results of this study,HIF-1αappears to play a distinct role in OSCC tumor progression,underscoring the importance of exploring hypoxia-driven changes in cellular phenotype at the ITF of OSCC.Further research is needed to better understand their impact on OSCC prognosis.
基金supported by the National Natural Science Foundation of China(81473453,81673800)the Projects of International Science and Technology Cooperation in Henan(182102410084).
文摘Objective MicroRNA-1(miR-1)aggravates myocardial ischemia–reperfusion(I/R)injury,whereas insulin-like growth factor-1(IGF-1)maintains cardiomyocyte homeostasis.In this study,the aim is to investigate whether miR-1 can exacerbate I/R injury through the regulation of IGF-1.Methods The infarct area,lactate dehydrogenase,miR-1 level,and apoptosis level were examined in the Langendorff isolated rat I/R model.The hypoxia–reoxygenation model of rat cardiacmyocytes and H9c2 cells were developed to determine the levels of miR-1,IGF-1 mRNA,and IGF-1 protein.Furthermore,the dual-luciferase assay was used to verify the relationship between miR-1 and IGF-1.Results Overexpression of miR-1 increased the level of apoptosis and decreased the IGF-1 expression.However,inhibition of miR-1 expression decreased the level of apoptosis,alleviated the degree of injury,and increased the IGF-1 expression.Overexpression of IGF-1 also reduced the degree of cellular damage and level of apoptosis caused by the overexpression of miR-1.When IGF-1 was knocked down,myocardial cells displayed more severe damage and a higher apoptosis level,even with decreased levels of miR-1.Conclusion miR-1 promotes apoptosis and aggravates I/R injury by downregulating IGF-1.
基金National Natural Science Foundation of China:Basic Research on the Mechanism of Organ Immune Damage and the Diagnosis and Treatment of Integrated Traditional Chinese and Western Medicine(No.32141005)。
文摘OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-inducible factor-1α(HIF-1α)and pyruvate kinase M2(PKM2)signaling pathway,along with the glycolysis metabolism pathway.METHODS:The animals were divided into the following groups:Model,Control,dapagliflozin,SHT low-dose,SHT medium-dose,and SHT high-dose.We assessed 24-hour urine protein(24 h-UTP)levels,urinary albuminto-creatinine ratio,and regularly monitored fasting blood glucose during the treatment period.After treatment,we examined renal tissue structure,renal function(urea nitrogen,uric acid,creatinine,cystatin C,β2-microglobulin),and glycolysis in renal macrophages.Additionally,we observed macrophage polarization in renal tissue and measured inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10,monocyte chemoattractant protein-1)to assess the immunoinflammatory status of the renal tissue.Finally,we investigated the expression of the HIF-1α/PKM2 signaling pathway in macrophages to explore its role in the glycolysis process.RESULTS:SHT shows a beneficial effect in treating DKD by reducing 24 h-UTP,regulating blood glucose levels,improving renal tissue structure,protecting renal function,inhibiting macrophage glycolysis,reducing macrophage transformation to the M1 state,and suppressing the expression of the HIF-1α/PKM2 signaling pathway.CONCLUSION:SHT may exert renoprotective effects by inhibiting macrophage glycolysis via the HIF-1α/PKM2 signaling pathway.This inhibition decreases macrophage M1 polarization and reduces immunoinflammatory injury in the renal tissue of DKD mice.
文摘BACKGROUND Hepatic ischemia reperfusion(HIR)injury is a major complication affecting various major liver surgeries,including liver transplantation.Aprepitant(APRE),a neurokinin-1 receptor antagonist,is commonly used as an antiemetic to prevent chemotherapy-induced nausea and vomiting.AIM To assess the potential protective effect of APRE against HIR-induced liver injury via targeting the nucleotide-binding oligomerization domain-,leucine-rich repeat-,and pyrin domain-containing receptor 3/interleukin(IL)-1beta signaling pathway.METHODS Six groups of adult male Wistar albino rats were divided as follows:Sham group,Sham/APRE10 group(APRE 10 mg/kg),HIR group,HIR/APRE5 group(APRE 5 mg/kg),HIR/APRE10 group(APRE 10 mg/kg),and HIR/APRE20 group(APRE 20 mg/kg).Serum alanine transaminase,aspartate transaminase,liver malondialdehyde,total antioxidant capacity levels,as well as IL-6,sirtuin 1(Sirt1),caspase-3,cleaved caspase-3,and tumor necrosis factor alpha biomarkers,were evaluated.Hepatic specimens were examined histopathologically and immunohistochemically for nuclear factor erythroid-2-related factor 2(Nrf2)immunoexpression.RESULTS HIR resulted in hepatic damage,as evidenced by histopathological changes and a significant increase in serum alanine transaminase,aspartate transaminase,hepatic malondialdehyde,caspase-3,and tumor necrosis factor alpha levels.Additionally,there were significant increases in hepatic total antioxidant capacity and reductions in IL-6 and cleaved caspase-3 protein levels,as demonstrated by Western blot analysis,along with enhanced immunoexpression of Sirt1 and Nrf2.APRE has significantly reduced various parameters of oxidative stress,inflammation,and apoptosis,and a significant increase in liver Nrf2 immunoexpression,leading to a significant improvement in the histopathological changes.CONCLUSION In conclusion,targeting the Sirt1/Nrf2 signaling pathway,as demonstrated by APRE in our model,could present a promising therapeutic target to protect against HIR-induced liver injury during major liver surgeries.
基金Key Program of Chongqing Municipal Health Bureau,No. 06-01-020
文摘BACKGROUND： Hypoxia-inducible factor-1 （HIF-1） accumulates under conditions of hypoxia. HIF-1α target genes have pleiotropic effects on neurogenesis, neuroprotection and angiogenesis in the brain. OBJECTIVE： To investigate whether a recombinant adenovirus carrying HIF-1α can increase the expression of HIF-I a in vivo and thus promote angiogenesis and neurogenesis in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING： The randomized, controlled experiment was performed at the Department of Neurobiology, Third Military Medical University of Chinese PLA from September 2006 to October 2007. MATERIALS： 68 healthy adult male Sprague-Dawley （SD） rats, weighing 230-250 g, were used. HIF-I a antibody was purchased from Wuhan Boster Company. Vascular endothelial growth factor （VEGF） antibody was purchased from Santa Cruz Biotech Company. METHODS： All 68 rats were induced with a transient middle cerebral artery occlusion （MCAO）, according to the method of intra-luminal vascular occlusion. 54 rats, in which MCAO was successfully induced, were randomly divided into adenovirus （Ad） group and recombinant adenovirus with HIF-1α gene （Ad-HIF-1α ） group （27 rats for each group）. Rats were injected with 10 μL Ad （Ad group） or Ad-HIF-1α （Ad-HIF-1α group） into the lateral ventricle, 1 day after MCAO induction. MAIN OUTCOME MEASURES： Reverse transcription polymerase chain reaction was used to measure the expression of HIF-1α and of VEGF. Immunohistochemistry was used to detect the localization of HIF-1α, VEGF and factor Ⅷ in ischemic penumbra. Rat newborn nerve cells were labeled with 5-bromodeoxyuridine （BrdU） after ischemia. BrdU/neurofilament 200 （NF200） and BrdU/glial fibrillary acidic protein （GFAP） double labeled immunofluorescent histochemistry was used to identify the differentiation of newborn cells. Neurological function was evaluated using the modified neurological severity score （NSS）. RESULTS： Compared with Ad, Ad-HIF-1α enhanced the expression of HIF-1α and VEGF （P 〈 0.01）. The numbers of factor VIII, BrdU, BrdU/NF200 and BrdU/GFAP positive cells were increased significantly （P 〈 0.01） in the Ad-HIF-I a group compared to the Ad group. Levels of HIF-1α and VEGF mRNA in the Ad-HIF-1α group were enhanced compared with those in the Ad group. NSS scores of the Ad-HIF-1α group were superior to those of the Ad group at days 7, 14, 21, and 28 after MCAO （P 〈 0.05）. CONCLUSION： HIF-1α gene therapy can increase angiogenesis and neurogenesis, and thus improve neurological function following cerebral ischemia in rats.
基金the Scientific and Technological Development Program of Qingdao City, No.05-1-NS-73
文摘BACKGROUND： Numerous studies have shown that transient ischemic preconditioning induces cerebral ischemic tolerance. However, the underlying mechanisms of endogenous protection following ischemic preconditioning remain unclear. OBJECTIVE： To dynamically measure erythropoietin and hypoxia-inducible factor-1α （HIF-1α） mRNA and protein expression at various times following preconditioning, and to investigate effects of erythropoietin and HIF-1α on cerebral ischemic tolerance in a model of focal ischemia/reperfusion established using the twice suture method. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Institute of Anatomy, Medical College, Qingdao University, China from March 2006 to March 2007. MATERIALS： Rabbit anti-rat HIF-1α monoclonal antibody and biotinylated goat anti-rabbit IgG （Boster, China）, rabbit anti-rat erythropoietin monoclonal antibody （Santa Cruz Biotechnology, USA）, and one-step RT-PCR kit （Qiagen, Germany） were used in this study. METHODS： A total of 99 healthy, male, Wistar rats were randomly assigned to three groups： sham surgery （n = 9）, non-ischemic preconditioning （n = 45）, and ischemic preconditioning （n = 45）. In the ischemic preconditioning group, rat models of pre-ischemia-reperfusion-ischemia-reperfusion were established by occluding the left middle cerebral artery using the twice suture method. In the non-ischemic preconditioning group, pre-ischemia was replaced by sham surgery. Subsequently, the ischemic preconditioning and non-ischemic preconditioning groups were equally divided into five subgroups according to time of first reperfusion, including 1-, 3-, 7-, 14-, and 21-day subgroups. The sham surgery group received the sham surgery twice. MAIN OUTCOME MEASURES： HIF-la and erythropoietin protein expression was measured in the cerebral cortex, corpus striatum, and hippocampus of the ischemic hemisphere. HIF-1α and erythropoietin mRNA expression were determined in the frontal and parietal cortex of the ischemic hemisphere. RESULTS： （1） Intergroup comparison： compared with the non-ischemic preconditioning group, HIF-1α protein expression significantly increased in the rat cerebral cortex, corpus striatum, and hippocampus in the ischemic hemisphere at 1,3, and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05 or P 〈 0.01）. Erythropoietin protein expression significantly increased in the cerebral cortex, corpus striatum, and hippocampus, as well as HIF-1α and erythropoietin mRNA expression in the frontal and parietal cortex in the ischemic hemisphere, at 3 and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05）. （2） Temporal expression： HIF-1α protein expression in the rat cerebral cortex, corpus striatum, and hippocampus, as well as HIF-la mRNA expression in the frontal and parietal cortex, in the ischemic hemisphere increased at 3 days, and gradually decreased from 7 days following reperfusion in the ischemic preconditioning group. Temporal erythropoietin protein and mRNA expression was consistent with HIF-1α protein expression. （3） Correlation： erythropoietin mRNA expression positively correlated with HIF-1α mRNA expression （r= 0.737, P 〈 0.01）. CONCLUSION： Ischemic preconditioning induced cerebral ischemic tolerance. Pre-ischemiainduced increase in endogenous HIF-1αexpression, as well as its target gene erythropoietin, participated in the formation of cerebral ischemic tolerance.
