ObjectiveTo observe the effects of A549 cells under hypoxicconditions on the migration of human umbilical vein endothelial cells (HUVECs) and microvascular formation. MethodsAfter cultured for 24 h in normoxia condition(21% O2),hypoxia condition (2% O2),and anaerobic condition (0% O2),respectively,morphology of A549 cells was observed with inverted phase contrast microscope,proliferation was detected by MTT assay,and intracellular hypoxia-inducible factor-1α (HIF-1α) protein was detected by immunocyto-chemical technique,for determining whether the hypoxia model is successful. Then A549 cells' supernatant in the normoxic group,the hypoxia group and HUVECs culture medium were taken to intervene HUVECs. The migration of HUVECs was observed with cell scratch test,pseudopodia formation of HUVECs was observed with microfilament green fluorescent staining method,and blood vessel formation was observed with three-dimensional culture techniques in vitro. ResultsCompared with the normoxic group,the growth of A549 cells was better in the hypoxia group with more proliferation,and was poor in the anaerobic group with decreased number of cells. A549 cells in the hypoxia group and the anaerobic group both expressed HIF-1α protein,which was more obvious in the anaerobic group. Compared with the HUVECs supernatant intervention group,the hypoxia supernatant intervention group and the normoxic supernatant intervention group both had varying degrees of migration,pseudopodia structure formation and vascular lumen sample structure formation,which were more obvious in the former group. ConclusionA549 cells in hypoxic environment grow very well,proliferated significantly,but anaerobic environment is not conducive to the growth of A549 cells which found to be apoptosis. A549 cells in hypoxic environment can promote HUVECs migration,pseudopodia formation and angiogenesis.
Objective To investigate the expressions of hypoxia-inducible factor-1α (HIF-1α) and caudal homeobox gene 2 (CDX2) in colorectal adenocarcinoma, and the relationships between them and the clinicopathologic factor of colorectal adenocarcinoma. Methods The expressions of HIF-1α and CDX2 were detected by immunohistochemistry in 62 specimens of colorectal adenocarcinoma and 20 specimens of normal colorectal mucosa tissue. The correlation between the expressions of HIF-1α and CDX2 was analyzed by Spearman rank correlation analysis. Results The positive rates of HIF-1α expression in normal colorectal mucosa tissue and colorectal adenocarcinoma were 5.0% （1/20） and 62.9% （39/62）, CDX2 were 95.0% （19/20） and 69.4% （43/62）, the differences of positive rate between different tissues were significant （Plt;0.05）. In colorectal adenocarcinoma, the expression of HIF-1α or CDX2 was related to tumor differentiation, lymph node metastasis, and Dukes staging (Plt;0.05). There was a negative correlation between HIF-1α and CDX2 expressions in colorectal adenocarcinoma （r=－0.293 2，Plt;0.05）. Conclusions The up-regulation of HIF-1α and down-regulation of CDX2 may be involved in the genesis of colorectal adenocarcinoma， and there is a negative correlation between the two kinds of protein. HIF-1α may participate in modulation of CDX2 expression and lead to accelerate the progression of colorectal carcinoma.
Objective To summarize the advance of bioenergetic metabolic mechanisms of cancer cell. Methods Literatures about the recent studies on the bioenergetic metabolic mechanisms of cancer cell were reviewed.Results Cancer cells required a steady source of metabolic energy in order to continue their uncontrolled growth and proliferation. Accelerated uptake of glucose and glycolysis was one of the biochemical characteristics of hypoxia cancer cells. Glucose transport and metabolism were essential for the survival of tumor cells, leading to poor prognosis. Conclusions The studies on relationships between hypoxia-inducible genes and cancer have come a new understanding of the bioenergetic metabolic mechanisms of cancer cell, become new and important supplementary means of diagnosis and treatment of cancer, and enhanced existing strategies so that the treatment could be more rationally applied and personalized for cancer patients.
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.
Objective To construct the responsive plasmid PTRE-HIF-1αof Tet-on gene expression system and examine its expression. Methods RT-nested PCR was performed on the total RNA extracted from hypoxia HepG2 cells to obtain the cDNA of HIF-1α, which was inserted into the responsive plasmid PTRE2hyg. DNA sequencing was performed after the recombinant of responsive plasmid PTRE-HIF-1α was identified by endonuclease digestion. This recombinant vector was transfected into HepG2Tet-on cells by means of liposome and its expression was examined by RT-PCR and Western blot under the control of deoxycycline. Results The amplified products were confirmed as the cDNA of HIF-1α by DNA sequencing. The responsive plasmid PTRE-HIF-1α verified by edonuclease digestion, was capable of expression in HepG2Tet-on cells and could be controlled by deoxycycline. Conclusion The responsive plasmid PTRE-HIF-1α of Tet-on expression system is constructed successfully, and it can express under the regulation of deoxycycline in the HepG2Tet-on cells.
Objective To investigate the preventive effect of simvastatin，a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor，on hypoxic pulmonary hypertension and the relation between it and the angiotensin Ⅱ receptor-1（AT1R） expression in pulmonary arteriole.Methods Thirty male Sprague-Drawley rats were randomly allocated into three groups：a control group，a hypoxic group and a simvastatin preventive group.The animal model of hypoxic pulmonary hypertension was established by exposing the rats to normobaric hypoxic condition（8 h×6 d×3 w），and the preventive group were treated with simvastatin 10 mg/kg before hypoxic processing while the control and hypoxic groups were treated with sodium chloride.The mean pulmonary pressure（mPAP），serum cholesterol concentration，right ventricular hypertrophy index [RV/（LV+S）]，percentage of the wall thickness in the external diameter（WT%），percentage of the wall area in the total vascular area（WA%），and the AT1R expression in pulmonary arterioles were measured.Results When compared with the hypoxic group，in the preventive group，the mPAP and RV/（LV+S）obviously reduced [（22.6±3.86）mm Hg vs （29.3±2.27）mm Hg，（25.13±0.75）% vs （33.18±1.58）%，Plt;0.01 respectively]，the indices of wall thickness of rat pulmonary arteriole and area also decreased significantly [WT%：（15.98±1.96）% vs （25.14±1.85）%；WA%：（54.60±3.94）% vs 74.77±4.52）%；Plt;0.01 respectively]，and the positive degree of AT1R still lessened noticeably（1.23±0.09 vs 1.57±0.13，Plt;0.01）.All of the indices above in the hypoxic group increased markedly compared with the control group（Plt;0.01 respectively）.However，the differences of serum cholesterol among three groups were not significant（Pgt;0.05）.Conclusions Simvastatin can suppress the expression of AT1R in pulmonary vessel and prevent hypoxic pulmonary hypertension.
Objective To investigate the influence of hypoxic preconditioning on pulmonary structure of rats exposed to simulated high altitude hypoxia and to explore the role of hypoxia inducible factor-1α（HIF-1α）.Methods Fifty-six Wistar rats were randomly divided into 7 groups(n=8 in each group),ie,a normal control group(N group)，an acute hypoxic control group(H0 group)，an acute hypoxic group(H1 group)，a 3 000 m hypoxic preconditioning group(C3.0 group)，a 3 000 m hypoxic preconditioning + acute hypoxic group (C3.1 group)，a 5 000 m hypoxic preconditioning group(C5.0 group)，and a 5 000 m hypoxic preconditioning + acute hypoxic group(C5.1 group).After treated with hypoxic preconditioning，the animals were exposed to simulated altitude of 6 000 m for 24 hours.Then the protein and mRNA expression of HIF-1α in lung of N，H0，C3.0 and C5.0 groups were assessed by Western blot and RT-PCR，respectively.The lung structure in N，H1，C3.1 and C5.1 groups was observed by light microscope and electron microscope.Results Pulmonary interstitial edema was apparently observed in H1 group，while significantly relieved in two hypoxic preconditioning groups.HIF-1α protein was not detected in rat lungs by Western blot analysis.Compared to N group，the levels of HIF-1α mRNA significantly increased in C3.0 group and C5.0 group(both Plt;0.01).Conclusions Hypoxic preconditioning can relieve hypoxic pulmonary interstitial edema and increase HIF-1α mRNA expression in rat lungs.HIF-1 may be involved in the process of hypoxic preconditioning in rat lungs.
睡眠过程中反复出现呼吸暂停造成的间歇低氧是阻塞性睡眠呼吸暂停低通气综合征( OSAHS) 的主要病理生理学特点, 它能够导致自主神经, 特别是交感神经兴奋性异常增高[1] , 后者可能是OSAHS合并心血管疾病包括高血压、充血性心力衰竭、心肌梗死以及心律失常的主要危险因素之一[2,3] 。现将慢性间歇低氧( chronic intermittent hypoxia,CIH) 所致交感神经异常兴奋的相关研究作一综述。
Objective To investigate the effects of matrine on cell proliferation and expression of connective tissue growth factor( CTGF) and hypoxia inducible factor-1α( HIF-1α) of human lung fibroblast ( WRC-5) in normoxia ( 21% O2, 74% N2 , 5% CO2 ) and hypoxia ( 1% O2, 94% N2 , 5% CO2 )conditions. Methods MRC-5 cells were cultured and divided into differrent groups interfered with different dose of Matrine ( final concentration of 0 ～3. 2 mmol / L) in normoxia or hypoxia for 24 h. Cells were dividedinto 8 groups according to culture conditions, ie. normoxiagroup( N0 group) , normoxia + matrine 0. 2 mmol / L group( N0. 2 group) , normoxia + matrine 0. 4 mmol / L group( N0. 4 group) , normoxia + matrine 0. 8 mmol / L group( N0. 8 group) , hypoxia group( H0 group) , hypoxia + matrine 0. 2 mmol /L group( H0. 2 group) , hypoxia +matrine 0. 4 mmol /L group( H0. 4 group) , and hypoxia + matrine 0. 8 mmol / L group( H0. 8 group) . The MTT assay was used to measure the cell proliferation activity. Western-blot assay was used to examine the expression of CTGF and HIF-1α. Results Hypoxia promoted the cell proliferation in all groups( P lt;0. 05) .Matrine inhibited the proliferation of WRC-5 cells in a concentration-dependent manner in hypoxia or normoxia conditions( P lt;0. 05) . The expression of CTGF andHIF-1αwas lower in normoxia and higher in hypoxia( P lt;0. 01) . Matrine inhibited the expression of CTGF and HIF-1αin a concentration-dependent manner in hypoxiaand normoxia( P lt;0. 05) . Conclusion Matrine can inhibit the cell proliferation and the expression of CTGF and HIF-1αof WRC-5 cells in normoxia and hypoxia in a concentration-dependent manner.
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.