ObjectiveTo investigate the role of PI3K/Akt/HIF-1αsignaling pathway in bleomycin-induced pulmonary fibrosis in mice. MethodsFifty-six C57BL/6 mice were randomly divided into a control group and a bleomycin (BLM) group.The pulmonary fibrosis model was induced by single intratracheal instillation of BLM(2.5 mg/kg) in the BLM group.Similarly, 0.9% saline was instilled directly into the trachea in the control group.Then all mice were sacrificed on 21st day.The lungs were collected for morphometric analysis with HE and Masson staining.The degree of pulmonary fibrosis was evaluated with Ashcroft score and content of hydroxyproline.The activity of PI3K/Akt/HIF-1αsignaling pathway and pro-surfactant protein C (Pro-SPC) were measured by Western blot.The level of collagen3 mRNA was assessed with quantitative real time PCR analysis.Collagen3 protein and numbers of apoptosis cells were observed with immuno-histochemistry. ResultsIt was exhibited that the thickening alveolar septa, accumulation of inflammatory cells, and fibrous obliteration in the BLM group but not in the control group.There was a significant difference in Ashcroft score and hydryoproline content in the BLM group.Meanwhile, the activity of PI3K/Akt/HIF-1αsignaling pathway was up-regulated and the protein of Pro-SPC was decreased in the BLM group.It was revealed that the numbers of apoptosis cells, expressions of Collagen3 protein and mRNA were increased in the BLM group. ConclusionAberrant activity of PI3K/Akt/HIF-1αsignaling pathway may aggravate the pulmonary fibrogenesis.
ObjectiveTo summarize the research progress of the regulation effect of hypoxia inducible factor (HIF) on intervertebral disc. MethodsThe domestic and foreign related literature about the regulation effect of HIF on intervertebral disc was reviewed, summarized, and analyzed. ResultsHIF is a key transcription factor that is in response to hypoxia by cells, which is widely distributed in tissues and organs, including intervertebral disc. Hypoxia inducible factor is expressed highest in the nucleus pulposus which has the lowest oxygen concentration in the intervertebral disc. The effects of HIF include the regulation of nucleus pulposus differentiation and development, maintenance of the survival, energy metabolism, and anabolism of nucleus pulposus cells, and maintenance of the stability of extracellular matrix. ConclusionHIF plays a vital role in the development and differentiation of intervertebral disc and maintenance of physiological function, which may become a target for the research of the mechanism and the treatment of intervertebral disc degeneration.
Objective To investigate the expression of telomerase reverse transcriptase (TERT) and cell apoptosis in neonatal rats with hypoxia ischemia brain damage (HIBD). Methods A total of 42 7-day-old SD rats (12-18 g, male or female) were randomly allocated into sham-operation group (n=6) and hypoxia-ischemia (HI) group (n=36). In HI group, the rats were anesthetized with ethylether. The right common carotid artery (CCA) was exposed and permanently l igated with a 7-0silk suture through a midl ine cervical incision. A duration of 2.5 hours of hypoxia (8%O2 / 92%N2) was used to produce HIBD model. For sham-operation group, the CCA was exposed without l igation or hypoxia. The brain tissues were harvested at 4, 8, 12, 24, 48, and 72 hours after completion of an HI insult. The expressions of TERT and CC3 were detected by immunohistochemical staining. The apoptosis cells were detected with TUNEL staining method. Results The expression of TERT was increased at 4 hours after HI injury, significantly increased at 24-48 hours and then decreased at 72 hours. The expression of CC3 was increased at 4 hours after HI injury, significantly increased at 24 hours and still maintained high expression at 48 hours and 72 hours. However, in the sham-operation group, both the expressions of TERT and CC3 were extremely low. The expression of TERT and CC3 were higher in the HI group than in the sham-operation group at different time points, and the differences were significant (P lt; 0.05). The TUNEL staining showed that the positive cells in hippocampus and cortical areas were increased at 4 hours after HI injury, significantly increased at 24-48 hours and maintained a high level at 72 hours. However, there was few positive cells in the sham-operation group. There were significant differences between the HI group and the sham-operation group at different time points (P lt; 0.05). Conclusion TERT could be induced by HI in neonatal rats, and might have a protective role in regulating the cell apoptosis in the neonatal HIBD.
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 effects and mechanism of 17β-estradiol on the retinal neovasularization in rats with oxygen-induced retinopathy (OIR). MethodsA total of 48 SD rats were randomly divided into control group A, control group B, experimental group A and experimental group B with 12 rats in each group. The rats in control group A and experimental group A received a hypodermic injection of 0.1 ml PBS, and the rats in control group B and experimental group B group received an a hypodermic injection of 0.1 ml 17β-estradiol. At postnatal day 7 (P7) and P14, the mRNA expression of vascular endothelial growth factor (VEGF) and Hypoxia-inducible factor (HIF) -1α in the retina were measured by real-time polymerase chain reaction (RTPCR). At P14, endothelial cell nuclei breaking through the internal limiting membrane were counted after staining with hematoxylin and eosin (HE), and the protein expression of VEGF was measured after immunohistochemical staining. The changes of retinal ultrastructure were observed by transmission electron microscopy. ResultsAt P14, the difference of the number of endothelial cell nuclei among four groups was statistically significant(F=10.7, P＜0.05). The number of endothelial cell nuclei in experimental group A was increased greater than that in control group A (P＜0.05) and experimental group B(q=5.16，P＜0.05). But there was no difference between control group A and experimental group B (q=0.25，P＞0.05). The difference of VEGF protein expression among the four groups was statistically significant (P＜0.05). Comparing experimental group A with control group A, B and experimental group B, the difference was statistically significant (P＜0.05). In experimental group A there was ganglion cell swelling, pale staining cytoplasm and mitochondria vacuolizationin, while these were normal in other three groups. At P7 and P14, the differences of VEGF and HIF-1 mRNA expression among four groups were statistically significant(F=14.7,16.1, 13.4, 17.5; P=0.001, 0.005, 0.003, 0.009). At P7, the VEGF mRNA expression in control group B was more than that in control group A (q=5.22, P＜0.05). The VEGF mRNA expression in experimental group B was more than that in experimental group A (q=4.32, P＜0.05). At P14, the VEGF mRNA expression in control group B was more than that in control group A (q=3.72, P＜0.05), but there was no difference of HIF-1 mRNA expression between two groups. The VEGF and HIF-1 mRNA expression in experimental group B were both decreased more than those in experimental group A (q=5.12, 4.08;P＜0.05). Conclusions 17β-estradiol has the effect of two way regulation in VEGF mRNA, which increases VEGF expression in retina under hyperoxic conditions so as to develop the vascular system; which reduces VEGF and HIF-1α expression so as to prevent pathologic neovascularization under hypoxic conditions. It provides some protection from the damage of retinal neovascularization.
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.
Objective To design and construct the eukaryotic expressed vector of suicide genes, which contained 5 copies of hypoxia-responsive element (5HRE), promoter of alpha-fetoprotein gene (AFPp） and nitroreductase from Escherichia coli. Methods The constructing processes were as follows: ①The design of primer: Suicide genes of NTR in the Escherichia coli, which contained 6his-tag gene (6his-tag), were cloned by overlapping PCR. ②The construction of 5HRE: The single strand of synthetized HRE oligonucleotide was annealed, and 5HRE was constructed by multiple recombinant clone. ③The recombination of NTR gene, 5HRE, AFPp and pIRES2-EGFP: pIRES2-EGFP, which had removed the instant early promoter of cytomegalovirus, was recombined with NTR gene, 5HRE, AFPp. In this way, the eukaryotic expressed vector of pIRES2-EGFP-5HRE-AFPp-NTR, which carried NTR gene, 5HRE, AFPp was finally constructed. Results NTR gene, which contained the fusion of 684-base pair and 6his-tag gene, was cloned successfully, and its sequence was coincident with the result published by Genbank. A 221-base pair of 5HRE was also constructed, which was in accordance with the expected sequences. The integrity of the eukaryotic expressed vector was verified by restriction enzyme digestion and DNA sequence analysis, respectively. Conclusion The eukaryotic expressed vector of pIRES2-EGFP-5HRE-AFPp-NTR is successfully constructed, which may be used for its further investigation in vitro.
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 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.
ObjectiveTo summarize the regulating mechanism of microRNA in tumor microenvironment. MethodThe literatures about the studies on the mechanism regulated by microRNA for tumor microenvironment were reviewed according to the results searched from PubMed in recent years. ResultsmicroRNA might be participated in regulation of tumor microenvironment factors such as hypoxia-inducible factor, tumor associated fibroblasts, extracellular matrix, which leaded to a change in biological behavior of tumor cells by reforming the microenviroment. ConclusionsmicroRNA has been participated in regulating many factors of tumor microenvironment. The change of neoplastic microenvironment has been recognized to play a critical role in the development of cancer. Therefore revealing microRNA mechanism for tumor microenvironment could not only help exploring the biological behavior of tumor cells, but also come an important insight for new means of diagnosis and treatment of cancer.