Objective To investigate whether desferoxamine (DFO) preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α (HIF- 1α) and erythropoietin ...Objective To investigate whether desferoxamine (DFO) preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α (HIF- 1α) and erythropoietin (EPO) in vivo and in vitro. Methods Rat model of cerebral ischemia was established by middle cerebral artery occlusion with or without DFO administration. Infarct size was examined by TTC staining, and the neurological severity score was evaluated according to published method. Cortical neurons were cultured under ischemia stress which was mimicked by oxygen-glucose deprivation (OGD), and the neuron damage was assessed by MTT assay. Immunofluorescent staining was employed to detect the expressions of HIF-1 and EPO. Results The protective effect induced by DFO (decreasing the infarction volume and ameliorating the neurological function) appeared at 2 d after administration ofDFO (post-DFO), lasted until 7 d and disappeared at 14 d (P 〈 0.05); the most effective action was observed at 3 d post-DFO. DFO induced tolerance of cultured neurons against OGD: neuronal viability was increased 23%, 34%, 40%, 48% and 56% at 8 h, 12 h, 24 h, 36 h, and 48 h, respectively, post-DFO (P 〈 0.05). Immunofluorescent staining found that HIF-1 α and EPO were upregulated in the neurons of rat brain at 3 d and 7 d post-DFO; increase of HIF-1 α and EPO appeared in cultured cortex neurons at 36 h and 48 h post-DFO. Conclusion DFO induced tolerance against focal cerebral ischemia in rats, and exerted protective effect on OGD cultured cortical neurons. DFO significant induced the expression of HIF- 1 α and EPO both in vivo and in vitro. DFO preconditioning can protect against cerebral ischemia, which may be associated with the synthesis of HIF- 1 α and EPO.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
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
We examined the effect of blocking the erythropoietin (Epo) signaling using an anti-Epo antibody, soluble form of Epo receptor (sEpoR) capable of binding to Epo or EpoR antagonist, and proved to be effective against x...We examined the effect of blocking the erythropoietin (Epo) signaling using an anti-Epo antibody, soluble form of Epo receptor (sEpoR) capable of binding to Epo or EpoR antagonist, and proved to be effective against xenografts of female reproductive organ malignancies and of cancer cell lines in nude mice. We transfected seven cancer cell lines of various origins to express constitutively active sEpoR, and examined their tumorigenesis in nude mice. Suppression of the tumor growth, decrease in viable and proliferating cells and reduction of vascular density were seen individually in all xenografts of transfected cell lines compared with the controls. Quantitative RT-PCR analyses showed that expression levels of Epo, EpoR, ?1A-adrenaline receptor (?1A-ADR) and muscalinic acetylcholine receptor subunit 3 mRNAs (m3-AchR) were higher in the majority of the wild-type xenografts than in the corresponding cell lines except for A549. In some of the transfected xenografts, EpoR, ?1A-ADR and m3-AchR mRNAs were down-regulated. Western blot analyses revealed that the constitutively activated ERK1/2MAPK was discernible in the majority of non-transfected cell lines and was reduced in the transfected cell lines. However, it was regained after exposure to acetylcholine and/or noradrenaline. These findings suggest that constitutively active sEpoR can effectively destroy the xenografts but signals from the autonomic neurotransmitters of the host produced under stress may interfere with this antitumor activity.展开更多
Chinese tonifying herbs, which are classified into four functional categories (namely, Yang, Qi, Yin, Blood) are commonly used for restoring normal body function and the prevention of diseases. To explore cell-based b...Chinese tonifying herbs, which are classified into four functional categories (namely, Yang, Qi, Yin, Blood) are commonly used for restoring normal body function and the prevention of diseases. To explore cell-based biological markers for Blood-enriching Chinese herbs, we investigate the effect of 11 commonly used Blood-enriching herbs on erythropoietin (EPO) production in HepG2 cells. Herbs for nourishing Yin were tested for determining the specificity of Blood-enriching herbs in inducing EPO production. In addition, the effects of Blood-enriching herbs on nitric oxide (NO) production in both HepG2 cells and human umbilical vein endothelial cells (HUVECs) were also investigated. The results indicated that methanolic extracts of Blood-enriching herbs (but not Yin-nourishing herbs) showed characteristic pharmacological activity in inducing EPO production in HepG2 cells and NO release in HUVECs. The experimental findings, therefore, support the use of cell-based EPO production and NO release as biological markers for Blood-enriching Chinese tonifying herbs.展开更多
Recent studies have found that erythropoietin promotes the recovery of neurological function after traumatic brain injury.However,the precise mechanism of action remains unclea r.In this study,we induced moderate trau...Recent studies have found that erythropoietin promotes the recovery of neurological function after traumatic brain injury.However,the precise mechanism of action remains unclea r.In this study,we induced moderate traumatic brain injury in mice by intrape ritoneal injection of erythro poietin for 3 consecutive days.RNA sequencing detected a total of 4065 differentially expressed RNAs,including 1059 mRNAs,92 microRNAs,799 long non-coding RNAs,and 2115circular RNAs.Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses revealed that the coding and non-coding RNAs that were differentially expressed after traumatic brain injury and treatment with erythropoietin play roles in the axon guidance pathway,Wnt pathway,and MAPK pathway.Constructing competing endogenous RNA networks showed that regulatory relationship between the differentially expressed non-coding RNAs and mRNAs.Because the axon guidance pathway was repeatedly enriched,the expression of Wnt5a and Ephb6,key factors in the axonal guidance pathway,was assessed.Ephb6 expression decreased and Wnt5a expression increased after traumatic brain injury,and these effects were reversed by treatment with erythro poietin.These findings suggest that erythro poietin can promote recove ry of nerve function after traumatic brain injury through the axon guidance pathway.展开更多
AIM:Anaemia caused by acute upper gastrointestinal bleeding is treated with blood transfusion or iron,but patients usually face a two-month recovery period from post- haemorrhage anaemia.This prospective,randomised,op...AIM:Anaemia caused by acute upper gastrointestinal bleeding is treated with blood transfusion or iron,but patients usually face a two-month recovery period from post- haemorrhage anaemia.This prospective,randomised,open, pilot study was designed to investigate whether recombinant human erythropoietin(Epoetin)therapy accelerate haematocrit increase in the post-bleeding recovery period. METHODS:We studied hospitalised patients admitted because of acute ulcer bleeding or haemorrhagic gastritis, who had a haematocrit of 27-33% and did not receive blood transfusions.One day after the endoscopic confirmation of cessation of bleeding,they were randomised either to erythropoietin(20 000 IU Epoetin alfa subcutaneously,on days 0,4 and 6)plus iron(100 mg im,on days 1-6,(G_1)or iron only(G_2).Haematocdt was measured on days 0,6,14, 30,45,and 60,respectively. RESULTS:One patient from G_1 and two from G_2 were lost to follow-up.Therefore,14 and 13 patients from G_1 and G_2 respectively were analysed.Demographic characteristics,serum iron,ferritin,total iron binding capacity,reticulocytes,and haernatoait were not significantly different at entry to the study. Median reticulocyte counts were significantly different between groups on day six(G_1:4.0,3.0-6.4 vs G_2:3.5,2.1-4.4%, P=0.03)and median haematocrit on day fourteen [G_1:35.9, 30.7-41.0 vs G_2:32.5,29.5-37.0%(median,range),P=0.04]. CONCLUSION:Erythropoietin administration significantly accelerates correction of anemia after acute ulcer bleeding. The haematocrit gain is equivalent to one unit of transfused blood two weeks after the bleeding episode.展开更多
Objective: This study compares hemoglobin and erythropoietin levels in patients with polycythemia vera and secondary polycythemia. Study Design: A retrospective cross-sectional study evaluating the serum erythropoieti...Objective: This study compares hemoglobin and erythropoietin levels in patients with polycythemia vera and secondary polycythemia. Study Design: A retrospective cross-sectional study evaluating the serum erythropoietin and hemoglobin levels in patients with polycythemia vera and secondary polycythemia. This study was performed simultaneously in Texas state of the U.S. and Fars Province in Iran. Methods: Hemoglobin, hematocrit and erythropoietin test results were collected from patients aged 19 to 75 years who were diagnosed with polycythemia vera and secondary polycythemia. Patients records with history of thrombocythemia, congestive heart failure, dyspnea, anemia and pregnant woman were excluded from study. Patients in each decade of life were examined in separate groups, so that changes in hemoglobin related to aging did not affect the research results. Results: 75% of the patients were men, and 25% were women. A total of 1580 patients were analyzed in this study. 57.3% of patients in UTMB and 38.8 patients in Iran have hemoglobin level above 17 mg/dl. 74% of patients in UTMB and 88% of patients in Iran have erythropoietin below 10 IU/mL. Polycythemia in UTMB was more common in people over 50 and in Iran in patients under 50 years old. The serum hemoglobin and erythropoietin levels in patients with polycythemia vera were not significantly different in compare to secondary polycythemia patients. Data showed that there were 84 polycythemia patients per 100,000 people. The results of this study in UTMB and Iran showed that 4.5% and 7%, respectively, of patients with polycythemia had a positive JAK2 test. Conclusion: Low erythropoietin levels may not be helpful in differentiating polycythemia vera from secondary polycythemia. .展开更多
Objective: In this study, we aimed to investigate umbilical cord blood CD33 and erythropoietin (EPO) levels of pregnants with abnormal umbilical and uterine artery doppler waveforms and to compare with normal pregnanc...Objective: In this study, we aimed to investigate umbilical cord blood CD33 and erythropoietin (EPO) levels of pregnants with abnormal umbilical and uterine artery doppler waveforms and to compare with normal pregnancies. Materials and Methods: Total 40 pregnant women were included in this study. Of these 40 women, while 20 patients had abnormal umbilical and uterine artery doppler waveforms, the other 20 patients had normal umbilical and uterine artery doppler waveforms. After the delivery, blood samples were taken from umbilical artery of double clemped umbilical cord for blood gas parameters, EPO and CD33 levels. Sociodemographic findings, antepartum, intrapartum test results, labor and delivery characteristics and newborn examination results were recorded. Blood gas parameters, EPO and CD33 levels between groups were analyzed. Mann-Whitney U test and t-test were used as statistical methods. Results: There were no differences between parity, gestational ages and newborn weights of the groups. Cord blood CD33 and EPO levels of group with abnormal umbilical and uterine artery doppler waveforms were significantly higher than group with normal umbilical and uterine artery doppler waveforms (p < 0.01). Conclusion: Pathology on doppler screen shows to us a connection between chronic hypoxemia and abnormal on doppler screen. Preference of high blood CD33 levels for cord blood transplantation especially during last years can also be used with preference of cord blood with abnormal doppler findings.展开更多
文摘Objective To investigate whether desferoxamine (DFO) preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α (HIF- 1α) and erythropoietin (EPO) in vivo and in vitro. Methods Rat model of cerebral ischemia was established by middle cerebral artery occlusion with or without DFO administration. Infarct size was examined by TTC staining, and the neurological severity score was evaluated according to published method. Cortical neurons were cultured under ischemia stress which was mimicked by oxygen-glucose deprivation (OGD), and the neuron damage was assessed by MTT assay. Immunofluorescent staining was employed to detect the expressions of HIF-1 and EPO. Results The protective effect induced by DFO (decreasing the infarction volume and ameliorating the neurological function) appeared at 2 d after administration ofDFO (post-DFO), lasted until 7 d and disappeared at 14 d (P 〈 0.05); the most effective action was observed at 3 d post-DFO. DFO induced tolerance of cultured neurons against OGD: neuronal viability was increased 23%, 34%, 40%, 48% and 56% at 8 h, 12 h, 24 h, 36 h, and 48 h, respectively, post-DFO (P 〈 0.05). Immunofluorescent staining found that HIF-1 α and EPO were upregulated in the neurons of rat brain at 3 d and 7 d post-DFO; increase of HIF-1 α and EPO appeared in cultured cortex neurons at 36 h and 48 h post-DFO. Conclusion DFO induced tolerance against focal cerebral ischemia in rats, and exerted protective effect on OGD cultured cortical neurons. DFO significant induced the expression of HIF- 1 α and EPO both in vivo and in vitro. DFO preconditioning can protect against cerebral ischemia, which may be associated with the synthesis of HIF- 1 α and EPO.
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.
文摘We examined the effect of blocking the erythropoietin (Epo) signaling using an anti-Epo antibody, soluble form of Epo receptor (sEpoR) capable of binding to Epo or EpoR antagonist, and proved to be effective against xenografts of female reproductive organ malignancies and of cancer cell lines in nude mice. We transfected seven cancer cell lines of various origins to express constitutively active sEpoR, and examined their tumorigenesis in nude mice. Suppression of the tumor growth, decrease in viable and proliferating cells and reduction of vascular density were seen individually in all xenografts of transfected cell lines compared with the controls. Quantitative RT-PCR analyses showed that expression levels of Epo, EpoR, ?1A-adrenaline receptor (?1A-ADR) and muscalinic acetylcholine receptor subunit 3 mRNAs (m3-AchR) were higher in the majority of the wild-type xenografts than in the corresponding cell lines except for A549. In some of the transfected xenografts, EpoR, ?1A-ADR and m3-AchR mRNAs were down-regulated. Western blot analyses revealed that the constitutively activated ERK1/2MAPK was discernible in the majority of non-transfected cell lines and was reduced in the transfected cell lines. However, it was regained after exposure to acetylcholine and/or noradrenaline. These findings suggest that constitutively active sEpoR can effectively destroy the xenografts but signals from the autonomic neurotransmitters of the host produced under stress may interfere with this antitumor activity.
文摘Chinese tonifying herbs, which are classified into four functional categories (namely, Yang, Qi, Yin, Blood) are commonly used for restoring normal body function and the prevention of diseases. To explore cell-based biological markers for Blood-enriching Chinese herbs, we investigate the effect of 11 commonly used Blood-enriching herbs on erythropoietin (EPO) production in HepG2 cells. Herbs for nourishing Yin were tested for determining the specificity of Blood-enriching herbs in inducing EPO production. In addition, the effects of Blood-enriching herbs on nitric oxide (NO) production in both HepG2 cells and human umbilical vein endothelial cells (HUVECs) were also investigated. The results indicated that methanolic extracts of Blood-enriching herbs (but not Yin-nourishing herbs) showed characteristic pharmacological activity in inducing EPO production in HepG2 cells and NO release in HUVECs. The experimental findings, therefore, support the use of cell-based EPO production and NO release as biological markers for Blood-enriching Chinese tonifying herbs.
基金supported by the National Natural Science Foundation of China,No.81771355the Natural Science Foundation of Chongqing Science and Technology Bureau,Nos.CSTC2015jcyjA10096,cstc2021jcyj-msxmX0262(all to ZL)。
文摘Recent studies have found that erythropoietin promotes the recovery of neurological function after traumatic brain injury.However,the precise mechanism of action remains unclea r.In this study,we induced moderate traumatic brain injury in mice by intrape ritoneal injection of erythro poietin for 3 consecutive days.RNA sequencing detected a total of 4065 differentially expressed RNAs,including 1059 mRNAs,92 microRNAs,799 long non-coding RNAs,and 2115circular RNAs.Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses revealed that the coding and non-coding RNAs that were differentially expressed after traumatic brain injury and treatment with erythropoietin play roles in the axon guidance pathway,Wnt pathway,and MAPK pathway.Constructing competing endogenous RNA networks showed that regulatory relationship between the differentially expressed non-coding RNAs and mRNAs.Because the axon guidance pathway was repeatedly enriched,the expression of Wnt5a and Ephb6,key factors in the axonal guidance pathway,was assessed.Ephb6 expression decreased and Wnt5a expression increased after traumatic brain injury,and these effects were reversed by treatment with erythro poietin.These findings suggest that erythro poietin can promote recove ry of nerve function after traumatic brain injury through the axon guidance pathway.
文摘AIM:Anaemia caused by acute upper gastrointestinal bleeding is treated with blood transfusion or iron,but patients usually face a two-month recovery period from post- haemorrhage anaemia.This prospective,randomised,open, pilot study was designed to investigate whether recombinant human erythropoietin(Epoetin)therapy accelerate haematocrit increase in the post-bleeding recovery period. METHODS:We studied hospitalised patients admitted because of acute ulcer bleeding or haemorrhagic gastritis, who had a haematocrit of 27-33% and did not receive blood transfusions.One day after the endoscopic confirmation of cessation of bleeding,they were randomised either to erythropoietin(20 000 IU Epoetin alfa subcutaneously,on days 0,4 and 6)plus iron(100 mg im,on days 1-6,(G_1)or iron only(G_2).Haematocdt was measured on days 0,6,14, 30,45,and 60,respectively. RESULTS:One patient from G_1 and two from G_2 were lost to follow-up.Therefore,14 and 13 patients from G_1 and G_2 respectively were analysed.Demographic characteristics,serum iron,ferritin,total iron binding capacity,reticulocytes,and haernatoait were not significantly different at entry to the study. Median reticulocyte counts were significantly different between groups on day six(G_1:4.0,3.0-6.4 vs G_2:3.5,2.1-4.4%, P=0.03)and median haematocrit on day fourteen [G_1:35.9, 30.7-41.0 vs G_2:32.5,29.5-37.0%(median,range),P=0.04]. CONCLUSION:Erythropoietin administration significantly accelerates correction of anemia after acute ulcer bleeding. The haematocrit gain is equivalent to one unit of transfused blood two weeks after the bleeding episode.
文摘Objective: This study compares hemoglobin and erythropoietin levels in patients with polycythemia vera and secondary polycythemia. Study Design: A retrospective cross-sectional study evaluating the serum erythropoietin and hemoglobin levels in patients with polycythemia vera and secondary polycythemia. This study was performed simultaneously in Texas state of the U.S. and Fars Province in Iran. Methods: Hemoglobin, hematocrit and erythropoietin test results were collected from patients aged 19 to 75 years who were diagnosed with polycythemia vera and secondary polycythemia. Patients records with history of thrombocythemia, congestive heart failure, dyspnea, anemia and pregnant woman were excluded from study. Patients in each decade of life were examined in separate groups, so that changes in hemoglobin related to aging did not affect the research results. Results: 75% of the patients were men, and 25% were women. A total of 1580 patients were analyzed in this study. 57.3% of patients in UTMB and 38.8 patients in Iran have hemoglobin level above 17 mg/dl. 74% of patients in UTMB and 88% of patients in Iran have erythropoietin below 10 IU/mL. Polycythemia in UTMB was more common in people over 50 and in Iran in patients under 50 years old. The serum hemoglobin and erythropoietin levels in patients with polycythemia vera were not significantly different in compare to secondary polycythemia patients. Data showed that there were 84 polycythemia patients per 100,000 people. The results of this study in UTMB and Iran showed that 4.5% and 7%, respectively, of patients with polycythemia had a positive JAK2 test. Conclusion: Low erythropoietin levels may not be helpful in differentiating polycythemia vera from secondary polycythemia. .
文摘Objective: In this study, we aimed to investigate umbilical cord blood CD33 and erythropoietin (EPO) levels of pregnants with abnormal umbilical and uterine artery doppler waveforms and to compare with normal pregnancies. Materials and Methods: Total 40 pregnant women were included in this study. Of these 40 women, while 20 patients had abnormal umbilical and uterine artery doppler waveforms, the other 20 patients had normal umbilical and uterine artery doppler waveforms. After the delivery, blood samples were taken from umbilical artery of double clemped umbilical cord for blood gas parameters, EPO and CD33 levels. Sociodemographic findings, antepartum, intrapartum test results, labor and delivery characteristics and newborn examination results were recorded. Blood gas parameters, EPO and CD33 levels between groups were analyzed. Mann-Whitney U test and t-test were used as statistical methods. Results: There were no differences between parity, gestational ages and newborn weights of the groups. Cord blood CD33 and EPO levels of group with abnormal umbilical and uterine artery doppler waveforms were significantly higher than group with normal umbilical and uterine artery doppler waveforms (p < 0.01). Conclusion: Pathology on doppler screen shows to us a connection between chronic hypoxemia and abnormal on doppler screen. Preference of high blood CD33 levels for cord blood transplantation especially during last years can also be used with preference of cord blood with abnormal doppler findings.