Objective To observe the influence of the expression of CD18 on the neutrophile and the leukocyte adhesion to retinal vascular endothelium by hypoxia-inducible factor-1 alpha (HIF-1alpha;) in early diabetic retinopathy rats. Methods Male Sprague-Dawley rats received intraperitoneal injection of streptozotocin to induce diabetes model. 18 diabetic rats were divided into 3 groups randomly after 2 months of diabetes induction, including diabetic group (group B), HIF-1alpha; anti-sense oligonucleotides (ASODN) injection group (group C) and HIF-1alpha; sense oligonucleotides (SODN) injection group (group D), the age and weigh matched health rats were chosen as control group (group A), with 6 rats in each group. Then group A and B rats received 5% glucose solution caudalis veins injection, group C and group D rats received HIF-1alpha; ASODN and HIF-1alpha; SODN caudalis veins injection, respectively(025 mg/kg).The level of CD18 on the neutrophil isolated from the peripheral blood was measured by flow cytometry. Retinal leukostasis was quantified with acridine orange leukocyte fluorography. Results The percentage of CD18 positive neutrophil cell was（44.93plusmn;3.60）% in group B，（18.66plusmn;1.52）% in group A，（31.66plusmn;4.72）% in group C，（51.00plusmn;5.66）% in group D. Compared with each other groups，the differences are statistically significant （F=42.46, Plt;0.001）. The number of positive staining cells of retinal leukocyte was （46.16plusmn;10.68）in group A，（133.83plusmn;20.43）in group B,（99.83plusmn;9.28）in group C，（121.33plusmn;10.23） in group C. Compared group B with group C，the number of positive staining cells raised about 2.89 times；compared group B with group C and D，the differences are statistically significant （P=0.12，95% confidence interval -3.69~28.69）. Conclusions In vivo, HIF-1alpha; can decreased the expression of CD18 on neutrophils from diabetic ratsprime; peripheral blood and the collection of retinal leukostasis in the diabetic animals. HIF-1alpha; may serve as a therapeutic target for the treatment and/or prevention of early diabetic retinopathy. （Chin J Ocul Fundus Dis，2008，24：268-271）
Objective To investigate the expression of hypoxia inducible factor 1α (HIF-1α) protein and the activation of phosphoinositid 3-kinase/Akt (PI3K/Akt) signal ing pathway in neurons under hypoxia ischemia condition,and to elucidate the role of PI3K/Akt on HIF-1α regulation in the developing neurons after hypoxia ischemia brain damage(HIBD). Methods Fifty-six SD rats aged 10 days were randomly divided into normal control group (n=12), sham operationgroup (n=12), experimental group (n=24), wortmannin treated group (n=4) and DMSO/PBS treated group (n=4). In theexperimental group, the rats were anesthetized with ethylether. The right common carotid artery was exposed and l igated. Then, they were exposed to hypoxia in a normobaric chamber filled with 8% oxygen and 92% nitrogen for 2.5 hours. In the sham control group, the right common carotid artery was exposed but was not l igated or exposed hypoxia. In the normal control group, the rats recevied no further processing. For wortmannin treated group and DMSO/PBS treated group, the rats received intraventricular injection of wortmannin or DMSO/PBS 30 minutes before hypoxia ischemia. The brain tissues were harvested from the rats in the normal control, sham operation and experimental groups at 4, 8 and 24 hours after hypoxia ischemia, but in the wortmannin and DMSO/PBS treated groups only at 4 hours. The HIF-1α protein expression and Akt protein expression were detected with immunohistochemistry method. HIF-1α, Akt and p-Akt protein expression were measured by Western blot analysis. Results In the experimental group, the HIF-1α expression was significantly increased at 4 hours after operation, reached the peak level at 8 hours, and began to decrease at 24 hours. The p-Akt protein was significantly increased at 4 hours, and began to decrease at 8 hours. However, the expression levels of HIF-1α and p-Akt protein in the normal control group were extremely low at each time point. So, the expression levels of HIF-1α in the experimental group was significantly higher than that in the normal control groups (P lt; 0.01), the expression of p-Akt protein in the experimental group at 4 and 8 hours was significant higher than that in the normal control group (P lt; 0.05). The change of Akt protein in the experimental group was not time-dependent, and no significant difference was evident when compared with that of the normal control group (P gt; 0.05). Using wortmannin, the PI3K/Akt specific inhibitor, HIF-1α protein expression was significantly decreased when compared with the DMSO/PBS treated group and experimental group (P lt; 0.01). Conclusion These results suggested that the HIBD of neonatal rats may activate PI3K/Akt signal ing pathway and further induce the expression of HIF-1α, indicating PI3K/Akt signal ing pathway and HIF-1α could be a potential target for treatment of neonatal HIBD.
The intervention therapy targeting vascular endothelial growth factor (VEGF) has become a specific and effective method for the treatment of diabetic retinopathy (DR). However, some patients did not respond or responded poorly to anti-VEGF therapy, and its effects of eliminating edema and improving vision appear to be unstable in the same patient. Hypoxia-inducible factor-1α (HIF-1α), an important upstream transcriptional regulator of VEGF, is an oxygen concentration-sensitive protein expressed in tissues under hypoxia. It can simultaneously target many downstream target genes except VEGF, such as placental growth factor and angiopoietin-like protein 4, to cause blood-retinal barrier damage and neovascularization, and thus participate in various pathological changes of DR to promote the occurrence and development of DR. Therefore, direct intervention of HIF-1α or targeting one or more downstream target genes regulated by HIF-1α to treat DR may have better efficacy. In the future, the development of effective and safe HIF inhibitors or anti-VEGF with HIF-1α other target gene inhibitors may have broader clinical application prospects.
Objective To elucidate whether glucose transporters-4 （GLUT-4） takes part in glucose uptake of mesenchymal stem cells （MSCs） and whether Akt gene improves translocation and expression of GLUT-4 in MSCs under hypoxic environment ex vivo. Methods MSCs, transfected by Akt gene and no, were cultured with normoxia (5% CO2) or hypoxia (94%N2, 1%O2 and 5% CO2) at 37 ℃ for 8 h. Glucose uptake was assayed by using radiation isotope 2-［3H］-deoxy-Dglucose (3H-G) and the expression of GLUT-4 protein and mRNA was assayed by immunocytochemistry, Western blot and RT-PCR, respectively. Results ①3 H-G intake of MSCs was significantly increased in hypoxiatransfection group than that in hypoxia-non-transfection 〔（1.39±0.13） fold, P＜0.05〕, but which was lower than that in normoxia-non-transfection group, P＜0.05. ②GLUT-4 was expressed by MSCs under any conditions. Compared with normoxia-non-transfection group, hypoxia decreased the expressions of GLUT-4 mRNA and protein significantly (P＜0.05). ③Compared with hypoxianontransfection group, the expression of GLUT-4 〔mRNA（1.756±0.152） fold, total protein in cell （1.653±0.312） fold, protein in plasma membrane （2.041±0.258） fold〕 was increased in hypoxia-transfection group significantly (P＜0.05), but which was lower than that in normoxianontransfection group (P＜0.05). ④There was significantly positive relation between 3H-G intake and GLUT-4 protein expression in plasma membrane (r=0.415, P=0.001).Conclusion GLUT-4 may take part in glucose uptake of MSCs, and the capability of Akt gene to improve MSCs anti-hypoxia may be finished by its role in increasing the expression and translocation of GLUT-4.
ObjectiveTo objectively evaluate the effect and safety of naloxone for the treatment of moderate and severe neonatal hypoxia-ischemic encephalopathy (HIE). MethodsResearch articles published from inception to June 2015 on Cochrane library, PubMed, Web of science, Chinese Science and Technology Journal Full-text Database, Digital Full-text Journal Database and Chinese Journal Full-text Database were searched, which were relevant to naloxone in the treatment of moderate and severe neonatal HIE. And two authors extracted information via standardized data extraction form and assessed the quality of included studies independently. RevMan 5.2 software was used for Meta-analysis. ResultsAt last, 20 randomized controlled trials (involving 1 519 neonates; 783 in the treatment group and 736 in the control group) were included. The results of meta-analysis showed that the effect of naloxone for moderate and severe HIE was significantly superior to the control group[OR=5.07, 95%CI (3.61, 7.12), P < 0.000 01]. The neurobehavioral scores in neonates treated by naloxone after 5, 7, 10, and 14 days were higher than those in the control group[WMD=6.61 points, 95%CI (5.70, 7.51) points, P < 0.000 01; WMD=4.27 points, 95%CI (2.63, 5.91) points, P < 0.000 01; WMD=2.40 points, 95%CI (1.47, 3.34) points, P < 0.000 01; WMD=2.58 points, 95%CI (1.00, 4.16) points, P=0.001], respectively; while the neurobehavioral scores after 3-day treatment between the two groups had no statistically difference[WMD=0.00 points, 95%CI(-0.76, 0.77) points, P=0.99]. What's more, the disappeared time of clinical symptoms and signs (breathing improvement time, recovery time, convulsions disappearance time, and signs disappearance time) in naloxone group was superior to the control groups[WMD=-3.78 hours, 95%CI (-6.93, -0.64) hours, P=0.02; WMD=-9.66 hours, 95%CI (-14.25, -5.06) hours, P < 0.001; WMD=-2.81 hours, 95%CI (-5.28, -0.35) hours, P=0.03; WMD=-1.02 days, 95%CI (-1.84, -0.20) days, P=0.01], respectively. ConclusionsNaloxone has certain therapeutic on moderate and severe HIE. Further high-quality randomized controlled trials should be carried out to provide more reliable evidence.
To review the role of hypoxia inducible factor 1α (HIF-1α) in hypoxic-ischemic injury and its repair, and to analyze the possible mechanisms. Methods Recent l iterature on HIF-1α and its role in hypoxic-ischemic injury was reviewed and analyzed. Results HIF-1α was involved in the hypoxic-ischemic injury of various organs or tissues and their repair processes. Conclusion HIF-1α has a potential to treat common cl inical hypoxic-ischemic injuries and has a promisingfuture for appl ication.
Objective To investigate the dynamic expression of small ubiquitin-related modifiers-1 ( SUMO-1) in lung tissue in different phases of rat model of hypoxic pulmonary hypertension( HPH) .Methods Forty Wistar rats were randomly divided into 5 groups, and exposed to normoxia or to normobaric intermittent hypoxia for 3, 7, 14 or 21 days, respectively. Mean pulmonary arterial pressure( mPAP) , right ventricle hypertrophy index ( RVHI) , and the ratio of the vessel wall area to the total area( WA% ) weremeasured. RT-PCR and in situ hybridization were used to determine the mRNA expression of SUMO-1.Immunohistochemistry and Western blot were used to determine the protein expression of SUMO-1. Results The hypoxic rats developed pulmonary vascular remodeling in pulmonary arterioles after 7 days of hypoxia,with WA% and mPAP significantly higher than those in the normal control. Pulmonary vascular remodeling aggravated with much higherWA% and mPAP afer 14 days of hypoxia, and reached the peak afer 21 days of hypoxia. SUMO-1 mRNA and protein expression markedly increased after 3 days of hypoxia, and reached peak after 14 days. After 21 days of hypoxia, SUMO-1 mRNA expression weakened but still higher than that in the normal control ( P lt; 0. 05) , and SUMO-1 protein expression remained stable. SUMO-1 mRNA and protein expression were positively correlated with mPAP, WA% and RVHI( all P lt; 0. 01) . Conclusion SUMO-1 is transcriptionally induced in lung tissue under chronic hypoxia, and thus involves in the pathogenesis of HPH.
Objective To investigate the relationship between the expression of hypoxia inducible factor 1α (HIF-1α) and the neuron apoptosis during a hypoxia ischemia brain damage and explore the role of HIF1α in regulating the neuron apoptosis and repairing the brain damaged by hypoxia and ischemia. Methods Forty SD rats aged 10 days were randomly divided into the experiment group and the control group, with 20 rats in each group. In the experimental group, the rats were anesthetized with ethylether. The right common carotid artery was exposed and ligated. Then, they were exposed to hypoxia ina normobaric chamber filled with 8% oxygen and 92% nitrogen for 2.5 hours. In the control group, the right common carotid artery was exposed but was not ligated or exposed to hypoxia. The brain tissues were harvested from the rats in the both groups at 4, 8, 24, 48 and 72 hours after the hypoxia and ischemia, and fromthe rats in the control group at the same time points. The HIF-1α protein expression and the cleaved caspase 3 (CC3) protein expression were detected with the immunohistochemistry method. The apoptosis cells were detected with the TUNEL staining method. Results In the experimental group, the HIF-1α expression was significantly increased at 4 hours after operation, at the peak level at 8 hours, and began to decrease at 24 hours. The CC3 protein was expressed at 4 hours after operation, and was slightly expressed at 8 hours, but was significantly increased at 24 hours; the higher levels were maintained at 48 and 72 hours. However, in the control group, both the expression levels of HIF-1α and the CC3 protein were extremely low. So, the expression levels of HIF-1α andthe CC3 protein were significantly higher in the experimental group than in the control group (P＜0.01). The TUNEL staining showed that in the experimentalgroup the positive cells were significantly increased after the hypoxia and ischemia, with a peak level at 72 hours after the hypoxia and ischemia; however, in the control group there were few positive cells.TUNEL positive cells in the experimental group were significantly more than that in the control group(P＜0.01).ConclusionThe expression tendency of HIF-1α is completely different from that of CC3.HIF-1α may have a protective role in regulating the neuron apoptosis in the neonatal hypoxia-ischemia brain damage and may promote the repairing and rebuilding process in the brain that was damaged by hypoxia and ischemia.
Objective To investigate the expression pattern of hypoxia-inducible factor 1α (HIF-1α) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. Methods A total of 66 SD rats (female or male) with weight (250 ± 20) g were randomly divided into 3 groups: normal control group (group A, n=6), pseudo injury group (group B, n=6), and spinal cord injury (SCI) group (group C, n=54). In group A, no treatment was given as normal control. In groupB, only laminectomy was appl ied. In group C, laminectomy was appl ied and static compression model of SCI was built at T10 level. The expression of HIF-1α was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with l ight staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of gl ial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-1α was poorly expressed in group A and increased a l ittle in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of gangl ion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then decl ined. At 14 days, it appeared only in a small amount of gangl ion cells of white matter. There was no significant difference in the number of HIF-1α positive cells between groups A and B (t=1.325, P=0.137). The number of HIF-1α positive cells at each time point in group C was more than those in groups A and B (P lt; 0.05), and there were significant differences between all time points in group C (P lt; 0.05). Conclusion The expression of HIF-1α increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation. MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope. ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups. ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.