Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)...Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.展开更多
Background:Circular RNAs(circRNAs)have been recognized as significant regulators of pulmonary hypertension(PH);however,the differential expression and function of circRNAs in different vascular cells under hypoxia rem...Background:Circular RNAs(circRNAs)have been recognized as significant regulators of pulmonary hypertension(PH);however,the differential expression and function of circRNAs in different vascular cells under hypoxia remain unknown.Here,we identified co-differentially expressed circRNAs and determined their putative roles in the proliferation of pulmonary artery smooth muscle cells(PASMCs),pulmonary microvascular endothelial cells(PMECs),and pericytes(PCs)under hypoxia.Methods:Whole transcriptome sequencing was performed to analyze the differential expression of circRNAs in three different vascular cell types.Bioinformatic analysis was used to predict their putative biological function.Quantitative real-time polymerase chain reaction,Cell Counting Kit-8,and EdU Cell Proliferation assays were carried out to determine the role of circular postmeiotic segregation 1(circPMS1)as well as its potential sponge mechanism in PASMCs,PMECs,and PCs.Results:PASMCs,PMECs,and PCs exhibited 16,99,and 31 differentially expressed circRNAs under hypoxia,respectively.CircPMS1 was upregulated in PASMCs,PMECs,and PCs under hypoxia and enhanced the proliferation of vascular cells.CircPMS1may upregulate DEP domain containing 1(DEPDC1)and RNA polymerase II subunit D expression by targeting microRNA-432-5p(miR-432-5p)in PASMCs,upregulate MAX interactor 1(MXI1)expression by targeting miR-433-3p in PMECs,and upregulate zinc finger AN1-type containing 5(ZFAND5)expression by targeting miR-3613-5p in PCs.Conclusions:Our results suggest that circPMS1 promotes cell proliferation through the miR-432-5p/DEPDC1 or miR-432-5p/POL2D axis in PASMCs,through the miR-433-3p/MXI1 axis in PMECs,and through the miR-3613-5p/ZFAND5 axis in PCs,which provides putative targets for the early diagnosis and treatment of PH.展开更多
Hypoxia-inducible factor 1(HIF1)has a crucial function in the regulation of oxygen levels in mammalian cells,especially under hypoxic conditions.Its importance in cardiovascular diseases,particularly in cardiac ischem...Hypoxia-inducible factor 1(HIF1)has a crucial function in the regulation of oxygen levels in mammalian cells,especially under hypoxic conditions.Its importance in cardiovascular diseases,particularly in cardiac ischemia,is because of its ability to alleviate cardiac dysfunction.The oxygen-responsive subunit,HIF1α,plays a crucial role in this process,as it has been shown to have cardioprotective effects in myocardial infarction through regulating the expression of genes affecting cellular survival,angiogenesis,and metabolism.Furthermore,HIF1αexpression induced reperfusion in the ischemic skeletal muscle,and hypoxic skin wounds in diabetic animal models showed reduced HIF1αexpression.Increased expression of HIF1αhas been shown to reduce apoptosis and oxidative stress in cardiomyocytes during acute myocardial infarction.Genetic variations in HIF1αhave also been found to correlate with altered responses to ischemic cardiovascular disease.In addition,a link has been established between the circadian rhythm and hypoxic molecular signaling pathways,with HIF1αfunctioning as an oxygen sensor and circadian genes such as period circadian regulator 2 responding to changes in light.This editorial analyzes the relationship between HIF1αand the circadian rhythm and highlights its significance in myocardial adaptation to hypoxia.Understanding the changes in molecular signaling pathways associated with diseases,specifically cardiovascular diseases,provides the opportunity for innovative therapeutic interventions,especially in low-oxygen environments such as myocardial infarction.展开更多
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
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
AIM:To examine the relevance of hypoxia inducible factor(HIF-1)and nitric oxide(NO)on the preservation of fatty liver against cold ischemia-reperfusion injury(IRI). METHODS:We used an isolated perfused rat liver model...AIM:To examine the relevance of hypoxia inducible factor(HIF-1)and nitric oxide(NO)on the preservation of fatty liver against cold ischemia-reperfusion injury(IRI). METHODS:We used an isolated perfused rat liver model and we evaluated HIF-1αin steatotic and non-steatotic livers preserved for 24 h at 4℃in University of Wisconsin and IGL-1 solutions,and then subjected to 2 h of normothermic reperfusion.After normoxic reperfusion,liver enzymes,bile production,bromosulfophthalein clearance,as well as HIF-1αand NO[endothelial NO synthase(eNOS)activity and nitrites/nitrates]were also measured.Other factors associated with the higher susceptibility of steatotic livers to IRI,such as mitochondrial damage and vascular resistance were evaluated. RESULTS:A significant increase in HIF-1αwas found in steatotic and non-steatotic livers preserved in IGL-1 after cold storage.Livers preserved in IGL-1 showed a significant attenuation of liver injury and improvement in liver function parameters.These benefits were enhanced by the addition of trimetazidine(an antiischemic drug),which induces NO and eNOS activation, to IGL-1 solution.In normoxic reperfusion,the presence of NO favors HIF-1αaccumulation,promoting also the activation of other cytoprotective genes,such as hemeoxygenase-1. CONCLUSION:We found evidence for the role of the HIF-1α/NO system in fatty liver preservation,especially when IGL-1 solution is used.展开更多
AIM: To study at what temperature the oxygen carried by the perfusate meets liver requirements in a model of organ perfusion. METHODS: in this study, we correlated hypoxia induciblefactor(Hi F)-1α expression to the p...AIM: To study at what temperature the oxygen carried by the perfusate meets liver requirements in a model of organ perfusion. METHODS: in this study, we correlated hypoxia induciblefactor(Hi F)-1α expression to the perfusion temperature and the hepatic oxygen uptake in a model of isolated perfused rat liver. Livers from Wistar rats were perfused for 6 h with an oxygenated medium at 10, 20, 30 and 37 ℃. Oxygen uptake was measured by an oxygen probe; lactate dehydrogenase activity, lactate release and glycogen were measured spectrophotometrically; bile flow was gravitationally determined; p H of the perfusate was also evaluated; Hi F-1α m RNA and protein expression were analyzed by real time-polymerase chain reaction and ELi SA, respectively. RESULTS: Livers perfused at 10 and 20 ℃ showed no difference in lactate dehydrogenase release after 6 h of perfusion(0.96 ± 0.23 vs 0.93 ± 0.09 m U/min per g) and had lower hepatic damage as compared to 30 and 37 ℃(5.63 ± 0.76 vs 527.69 ± 45.27 m U/min per g, respectively, P s < 0.01). After 6 h, tissue ATP was significantly higher in livers perfused at 10 and 20 ℃than in livers perfused at 30 and 37 ℃(0.89 ± 0.06 and 1.16 ± 0.05 vs 0.57 ± 0.09 and 0.33 ± 0.08 nmol/mg, respectively, P s < 0.01). No sign of hypoxia was observed at 10 and 20 ℃, as highlighted by low lactate release respect to livers perfused at 30 and 37 ℃(121.4 ± 12.6 and 146.3 ± 7.3 vs 281.8 ± 45.3 and 1094.5 ± 71.7 nmol/m L, respectively, P s < 0.02), and low relative Hi F-1α m RNA(0.40 ± 0.08 and 0.20 ± 0.03 vs 0.60 ± 0.20 and 1.47 ± 0.30, respectively, P s < 0.05) and protein(3.72 ± 0.16 and 3.65 ± 0.06 vs 4.43 ± 0.41 and 6.44 ± 0.82, respectively, P s < 0.05) expression.CONCLUSION: Livers perfused at 10 and 20 ℃ show no sign of liver injury or anaerobiosis, in contrast to livers perfused at 30 and 37 ℃.展开更多
Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain...Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by ir- radiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving frac- tion. EGFP-LC3 plasmid was stably transfected into cells to monitor autopbagic processes. Western blotting was used to evaluate the protein expression levels of HIF-lα, c-Jun, phosphorylated c-Jun, Be- clin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phos- phorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Be- clin 1 expression, instead of HIF-1α, could be blocked by SP600125 （a specific inhibitor of c-Jun NH2- terminal kinase）, followed by suppression of autophagy. Under hypoxia, combined treatment of irradia- tion and chloroquine （a potent autophagy inhibitor） significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclinl expression may be considered as a target to reverse the radioresistance in cancer cells.展开更多
Background Increasing research suggests that mitochondrial defect plays a major role in pulmonary hypertension(PH) pathogenesis. Mitochondrial dynamics and quality control have a central role in the maintenance of the...Background Increasing research suggests that mitochondrial defect plays a major role in pulmonary hypertension(PH) pathogenesis. Mitochondrial dynamics and quality control have a central role in the maintenance of the cell proliferation and apoptosis balance. However, the molecular mechanism underlying of this balance is still unknown. Methods To clarify the biological effects of hypoxic air exposure and hypoxia-inducible factor-1α(HIF-1α) on pulmonary arterial smooth muscle cell(PASMC) and pulmonary arterial hypertension rats, the cells were cultured in a hypoxic chamber under oxygen concentrations. Cell viability, reactive oxygen species level, cell death, mitochondrial morphology, mitochondrial membrane potential, mitochondrial function and mitochondrial biosynthesis, as well as fission-and fusion-related proteins, were measured under hypoxic conditions. In addition, rats were maintained under hypoxic conditions, and the right ventricular systolic pressure, right ventricular hypertrophy index and right ventricular weight/body weight ratio were examined and recorded. Further, we assessed the role of HIF-1α in the development and progression of PH using HIF-1α gene knockdown using small interfering RNA transfection. Mdivi-1 treatment was performed before hypoxia to inhibit dynamin-related protein 1(Drp1). Results We found that HIF-1α expression was increased during hypoxia, which was crucial for hypoxia-induced mitochondrial dysfunction and hypoxia-stimulated PASMCs proliferation and apoptosis. We also found that targeting mitochondrial fission Drp1 by mitochondrial division inhibitor Mdivi-1 was effective in PH model rats. The results showed that mitochondrial dynamics were involved in the pulmonary vascular remodeling under hypoxia in vivo and in vitro. Furthermore, HIF-1α also modulated mitochondrial dynamics in pulmonary vascular remodeling under hypoxia through directly regulating the expression of Drp1. Conclusions In conclusion, our data suggests that abnormal mitochondrial dynamics could be a marker for the early diagnosis of PH and monitoring disease progression. Further research is needed to study the signaling pathways that govern mitochondrial fission/fusion in PH.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
AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were ...AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were detected in human CRC tissues by immunohistochemistry and quantitative realtime polymerase chain reaction(q RT-PCR). SW480 and HT-29 cells were exposed to normoxia or hypoxia. Protein and m RNA levels of HIF-1α and MTH-1 were analyzed by western blotting and q RT-PCR, respectively. In order to determine the effect of HIF-1α on the expression of MTH-1 and the amount of 8-oxodeoxyguanosine triphosphate(d GTP) in SW480 and HT-29 cells, HIF-1α was silenced with small interfering RNA(si RNA). Growth studies were conducted on cells with HIF-1α inhibition using a xenograft tumor model. Finally, MTH-1 protein was detected by western blotting in vivo.RESULTS: High MTH-1 m RNA expression was detected in 64.2% of cases(54/84), and this was significantly correlated with tumor stage(P = 0.023) and size(P = 0.043). HIF-1α protein expression was correlated significantly with MTH-1 expression(R = 0.640; P < 0.01) in human CRC tissues. Hypoxic stress induced m RNA and protein expression of MTH-1 in SW480 and HT-29 cells. Inhibition of HIF-1α by si RNA decreased the expression of MTH-1 and led to the accumulation of 8-oxo-d GTP in SW480 and HT-29 cells. In the in vivo xenograft tumor model, expression of MTH-1 was decreased in the HIF-1α si RNA group, and the tumor volume was much smaller than that in the mock si RNA group.CONCLUSION: MTH-1 expression in CRC cells was upregulated via HIF-1α in response to hypoxic stress, emphasizing the crucial role of HIF-1α-induced MTH-1 in tumor growth.展开更多
BACKGROUND:Hepatic hypoxia-inducible factor-1(HIF-1) is activated in the progression of hepatocellular carcinoma (HCC).This study aimed to investigate the dynamic alterations of HIF-1αand its gene expression so as to...BACKGROUND:Hepatic hypoxia-inducible factor-1(HIF-1) is activated in the progression of hepatocellular carcinoma (HCC).This study aimed to investigate the dynamic alterations of HIF-1αand its gene expression so as to explore the relationship between HIF-1αexpression and hepatocarcinogenesis at the early stage of HCC. METHODS:A hepatoma model was made with 2-fluorenyl- acetamide(2-FAA)in male Sprague-Dawley rats.Morphological changes of rat hepatocytes were assessed pathologically (HE staining).The dynamic expression of hepatic and circulating HIF-1αwas quantitatively analyzed by ELISA. The gene fragments of hepatic HIF-1αmRNA were amplified by RT-PCR and confirmed by sequencing.The cellular distribution of hepatic HIF-1αexpression was confirmed by immunohistochemistry. RESULTS:Histological examination confirmed granulelike degeneration to atypical hyperplasia and HCC development in rat hepatocytes and progressive increases in the levels of hepatic and circulating HIF-1αand its gene expression during the course.The levels of HIF-1α expression in the liver and blood of rats with hepatoma were significantly higher than those in normal ratsand those with degeneration.Immunohistochemical analysis confirmed the positive expression and hepatocyte distribution of HIF-1αin the development of rat hepatoma. A positive relationship was found between HIF-1α expression in the liver and blood(P<0.01). CONCLUSIONS:The above observations support the hypothesis that the overexpression of HIF-1αand its gene are closely associated with the malignant transformation of hepatocytes and play an important role at the stage of hepatocarcinogenesis.展开更多
BACKGROUND： Neural stem cell （NSC） survival is closely associated with cell apoptosis in ischemic-hypoxic regions following transplantation. Numerous studies have revealed that X-box binding protein 1 （XBP1） is a...BACKGROUND： Neural stem cell （NSC） survival is closely associated with cell apoptosis in ischemic-hypoxic regions following transplantation. Numerous studies have revealed that X-box binding protein 1 （XBP1） is a transcription factor during endoplasmic reticulum unfolded protein response and is essential for cell survival, differentiation, and anti-apoptotic effects. OBJECTIVE： To determine the effects of the XBP1 gene on NSC proliferation and apoptosis under hypoxic conditions following XBP1 gene transfection into rat embryonic hippocampal NSCs using recombinant adenovirus vector. DESIGN, TIME AND SETTING： In vitro experiments were performed at the Laboratory of Cell Biology of Jilin University and Laboratory of Proteomics, Department of Neurology, Jilin University China from September 2008 to November 2009. MATERIALS： Recombinant adenovirus package XBP1 gene and Ad-XBPl-enhanced green fluorescent protein plasmid （Guangzhou Easywin BioMed Technology, China）, rabbit anti-XBP1 and its target gene estrogen receptor degradation-enhancing a-mannosidase-like protein （EDEM） glucose-regulated protein 78 （GRP78）, anti-apoptotic molecule Bcl-2 and proapoptotic molecule Bax polyclonal antibody （Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA）, and COCI2 （Sigma, St. Louis, MO, USA） were used in the present study. METHODS： Hippocampi from embryonic, Sprague Dawley rats on gestational day 16 were harvested for NSC isolation and cloning, followed by immunofluorescence for Nestin and sub-culturing. The recombinant adenovirus Ad-XBPl-enhanced green fluorescent protein plasmid was transfected into rat embryonic hippocampal NSCs, and then CoCl2 was applied to induce hypoxia. MAIN OUTCOME MEASURES： Cell quantification and 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide colorimetric assay were utilized to detect proliferation in XBPl-transfected NSCs for 7 consecutive days. Western blot assay was utilized to quantify XBP1 GRP78, EDEM, Bcl-2, and Bax expression. Flow cytometry was used to measure apoptosis. RESULTS： NSC proliferation was significantly enhanced following XBP1 gene transfection （P 〈 0.05）. Under hypoxic conditions, GRP78, EDEM, and Bcl-2 levels increased, but Bax levels decreased. In addition, NSC apoptosis decreased following transfection （P 〈 0.05）. CONCLUSION： The XBP1 gene was successfully transfected into rat embryonic hippocampal NSCs using a recombinant adenovirus vector. NSC proliferation following transfection, as well as anti-apoptotic effects under hypoxia, was significantly increased.展开更多
基金supported by the Fujian Minimally Invasive Medical Center Foundation,No.2128100514(to CC,CW,HX)the Natural Science Foundation of Fujian Province,No.2023J01640(to CC,CW,ZL,HX)。
文摘Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.
基金Central University Basic Research Fund of China,Grant/Award Number:22120220562National Natural Science Foundation of China,Grant/Award Number:81870044+1 种基金Natural Science Foundation of Shanghai,Grant/Award Number:201409004100 and 21ZR1453800Shanghai Pulmonary Hospital,Grant/Award Number:FKLY20005 and fkzr2320。
文摘Background:Circular RNAs(circRNAs)have been recognized as significant regulators of pulmonary hypertension(PH);however,the differential expression and function of circRNAs in different vascular cells under hypoxia remain unknown.Here,we identified co-differentially expressed circRNAs and determined their putative roles in the proliferation of pulmonary artery smooth muscle cells(PASMCs),pulmonary microvascular endothelial cells(PMECs),and pericytes(PCs)under hypoxia.Methods:Whole transcriptome sequencing was performed to analyze the differential expression of circRNAs in three different vascular cell types.Bioinformatic analysis was used to predict their putative biological function.Quantitative real-time polymerase chain reaction,Cell Counting Kit-8,and EdU Cell Proliferation assays were carried out to determine the role of circular postmeiotic segregation 1(circPMS1)as well as its potential sponge mechanism in PASMCs,PMECs,and PCs.Results:PASMCs,PMECs,and PCs exhibited 16,99,and 31 differentially expressed circRNAs under hypoxia,respectively.CircPMS1 was upregulated in PASMCs,PMECs,and PCs under hypoxia and enhanced the proliferation of vascular cells.CircPMS1may upregulate DEP domain containing 1(DEPDC1)and RNA polymerase II subunit D expression by targeting microRNA-432-5p(miR-432-5p)in PASMCs,upregulate MAX interactor 1(MXI1)expression by targeting miR-433-3p in PMECs,and upregulate zinc finger AN1-type containing 5(ZFAND5)expression by targeting miR-3613-5p in PCs.Conclusions:Our results suggest that circPMS1 promotes cell proliferation through the miR-432-5p/DEPDC1 or miR-432-5p/POL2D axis in PASMCs,through the miR-433-3p/MXI1 axis in PMECs,and through the miR-3613-5p/ZFAND5 axis in PCs,which provides putative targets for the early diagnosis and treatment of PH.
基金Supported by Croatian Ministry of Science and Education,Josip Juraj Strossmayer University of Osijek,Faculty of Dental Medicine and Health,Osijek,Croatia,No.IP7-FDMZ-2023West-Siberian Science and Education Center,Government of Tyumen District,Decree of 20.11.2020,No.928-rpMinistry of Science and Higher Education,No.FMEN 2022-0009.
文摘Hypoxia-inducible factor 1(HIF1)has a crucial function in the regulation of oxygen levels in mammalian cells,especially under hypoxic conditions.Its importance in cardiovascular diseases,particularly in cardiac ischemia,is because of its ability to alleviate cardiac dysfunction.The oxygen-responsive subunit,HIF1α,plays a crucial role in this process,as it has been shown to have cardioprotective effects in myocardial infarction through regulating the expression of genes affecting cellular survival,angiogenesis,and metabolism.Furthermore,HIF1αexpression induced reperfusion in the ischemic skeletal muscle,and hypoxic skin wounds in diabetic animal models showed reduced HIF1αexpression.Increased expression of HIF1αhas been shown to reduce apoptosis and oxidative stress in cardiomyocytes during acute myocardial infarction.Genetic variations in HIF1αhave also been found to correlate with altered responses to ischemic cardiovascular disease.In addition,a link has been established between the circadian rhythm and hypoxic molecular signaling pathways,with HIF1αfunctioning as an oxygen sensor and circadian genes such as period circadian regulator 2 responding to changes in light.This editorial analyzes the relationship between HIF1αand the circadian rhythm and highlights its significance in myocardial adaptation to hypoxia.Understanding the changes in molecular signaling pathways associated with diseases,specifically cardiovascular diseases,provides the opportunity for innovative therapeutic interventions,especially in low-oxygen environments such as myocardial infarction.
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.
基金Supported by The Ministerio de de Sanidad y Consumo(PI081988)CIBER-EHD,Instituto Carlos Ⅲ,Madrid and Ministerio de Asuntos Exteriores y de Cooperación Internacionales(A/020255/08 and A/02987/09),Madrid
文摘AIM:To examine the relevance of hypoxia inducible factor(HIF-1)and nitric oxide(NO)on the preservation of fatty liver against cold ischemia-reperfusion injury(IRI). METHODS:We used an isolated perfused rat liver model and we evaluated HIF-1αin steatotic and non-steatotic livers preserved for 24 h at 4℃in University of Wisconsin and IGL-1 solutions,and then subjected to 2 h of normothermic reperfusion.After normoxic reperfusion,liver enzymes,bile production,bromosulfophthalein clearance,as well as HIF-1αand NO[endothelial NO synthase(eNOS)activity and nitrites/nitrates]were also measured.Other factors associated with the higher susceptibility of steatotic livers to IRI,such as mitochondrial damage and vascular resistance were evaluated. RESULTS:A significant increase in HIF-1αwas found in steatotic and non-steatotic livers preserved in IGL-1 after cold storage.Livers preserved in IGL-1 showed a significant attenuation of liver injury and improvement in liver function parameters.These benefits were enhanced by the addition of trimetazidine(an antiischemic drug),which induces NO and eNOS activation, to IGL-1 solution.In normoxic reperfusion,the presence of NO favors HIF-1αaccumulation,promoting also the activation of other cytoprotective genes,such as hemeoxygenase-1. CONCLUSION:We found evidence for the role of the HIF-1α/NO system in fatty liver preservation,especially when IGL-1 solution is used.
基金Supported by Grant from Fondazione Cariplo,No.2011-0439
文摘AIM: To study at what temperature the oxygen carried by the perfusate meets liver requirements in a model of organ perfusion. METHODS: in this study, we correlated hypoxia induciblefactor(Hi F)-1α expression to the perfusion temperature and the hepatic oxygen uptake in a model of isolated perfused rat liver. Livers from Wistar rats were perfused for 6 h with an oxygenated medium at 10, 20, 30 and 37 ℃. Oxygen uptake was measured by an oxygen probe; lactate dehydrogenase activity, lactate release and glycogen were measured spectrophotometrically; bile flow was gravitationally determined; p H of the perfusate was also evaluated; Hi F-1α m RNA and protein expression were analyzed by real time-polymerase chain reaction and ELi SA, respectively. RESULTS: Livers perfused at 10 and 20 ℃ showed no difference in lactate dehydrogenase release after 6 h of perfusion(0.96 ± 0.23 vs 0.93 ± 0.09 m U/min per g) and had lower hepatic damage as compared to 30 and 37 ℃(5.63 ± 0.76 vs 527.69 ± 45.27 m U/min per g, respectively, P s < 0.01). After 6 h, tissue ATP was significantly higher in livers perfused at 10 and 20 ℃than in livers perfused at 30 and 37 ℃(0.89 ± 0.06 and 1.16 ± 0.05 vs 0.57 ± 0.09 and 0.33 ± 0.08 nmol/mg, respectively, P s < 0.01). No sign of hypoxia was observed at 10 and 20 ℃, as highlighted by low lactate release respect to livers perfused at 30 and 37 ℃(121.4 ± 12.6 and 146.3 ± 7.3 vs 281.8 ± 45.3 and 1094.5 ± 71.7 nmol/m L, respectively, P s < 0.02), and low relative Hi F-1α m RNA(0.40 ± 0.08 and 0.20 ± 0.03 vs 0.60 ± 0.20 and 1.47 ± 0.30, respectively, P s < 0.05) and protein(3.72 ± 0.16 and 3.65 ± 0.06 vs 4.43 ± 0.41 and 6.44 ± 0.82, respectively, P s < 0.05) expression.CONCLUSION: Livers perfused at 10 and 20 ℃ show no sign of liver injury or anaerobiosis, in contrast to livers perfused at 30 and 37 ℃.
基金supported by the National Natural Science Foundation of China(No.81201779)
文摘Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncol- ogy. The hypoxia-inducible factor （HIF）-lα plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by ir- radiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving frac- tion. EGFP-LC3 plasmid was stably transfected into cells to monitor autopbagic processes. Western blotting was used to evaluate the protein expression levels of HIF-lα, c-Jun, phosphorylated c-Jun, Be- clin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phos- phorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Be- clin 1 expression, instead of HIF-1α, could be blocked by SP600125 （a specific inhibitor of c-Jun NH2- terminal kinase）, followed by suppression of autophagy. Under hypoxia, combined treatment of irradia- tion and chloroquine （a potent autophagy inhibitor） significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclinl expression may be considered as a target to reverse the radioresistance in cancer cells.
基金supported by the National Natural Science Foundation of China (No. 81673858, No. 81704062, No. 30500644)the Science and Technology Project of Traditional Chinese Medicine in Hunan (No. 2009045, No. 2012027)the Program for National Center for Clinical Medicine for Geriatric Diseases (Ministry of Science and Technology)
文摘Background Increasing research suggests that mitochondrial defect plays a major role in pulmonary hypertension(PH) pathogenesis. Mitochondrial dynamics and quality control have a central role in the maintenance of the cell proliferation and apoptosis balance. However, the molecular mechanism underlying of this balance is still unknown. Methods To clarify the biological effects of hypoxic air exposure and hypoxia-inducible factor-1α(HIF-1α) on pulmonary arterial smooth muscle cell(PASMC) and pulmonary arterial hypertension rats, the cells were cultured in a hypoxic chamber under oxygen concentrations. Cell viability, reactive oxygen species level, cell death, mitochondrial morphology, mitochondrial membrane potential, mitochondrial function and mitochondrial biosynthesis, as well as fission-and fusion-related proteins, were measured under hypoxic conditions. In addition, rats were maintained under hypoxic conditions, and the right ventricular systolic pressure, right ventricular hypertrophy index and right ventricular weight/body weight ratio were examined and recorded. Further, we assessed the role of HIF-1α in the development and progression of PH using HIF-1α gene knockdown using small interfering RNA transfection. Mdivi-1 treatment was performed before hypoxia to inhibit dynamin-related protein 1(Drp1). Results We found that HIF-1α expression was increased during hypoxia, which was crucial for hypoxia-induced mitochondrial dysfunction and hypoxia-stimulated PASMCs proliferation and apoptosis. We also found that targeting mitochondrial fission Drp1 by mitochondrial division inhibitor Mdivi-1 was effective in PH model rats. The results showed that mitochondrial dynamics were involved in the pulmonary vascular remodeling under hypoxia in vivo and in vitro. Furthermore, HIF-1α also modulated mitochondrial dynamics in pulmonary vascular remodeling under hypoxia through directly regulating the expression of Drp1. Conclusions In conclusion, our data suggests that abnormal mitochondrial dynamics could be a marker for the early diagnosis of PH and monitoring disease progression. Further research is needed to study the signaling pathways that govern mitochondrial fission/fusion in PH.
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.
基金Supported by The National Natural Science Foundation of ChinaNo.81330013 and No.81272078 to Yang H+2 种基金No.81270451 to Xiao WDthe Program for Changjiang Scholars and Innovative Research Team in UniversitiesNo.13051 to Yang H
文摘AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were detected in human CRC tissues by immunohistochemistry and quantitative realtime polymerase chain reaction(q RT-PCR). SW480 and HT-29 cells were exposed to normoxia or hypoxia. Protein and m RNA levels of HIF-1α and MTH-1 were analyzed by western blotting and q RT-PCR, respectively. In order to determine the effect of HIF-1α on the expression of MTH-1 and the amount of 8-oxodeoxyguanosine triphosphate(d GTP) in SW480 and HT-29 cells, HIF-1α was silenced with small interfering RNA(si RNA). Growth studies were conducted on cells with HIF-1α inhibition using a xenograft tumor model. Finally, MTH-1 protein was detected by western blotting in vivo.RESULTS: High MTH-1 m RNA expression was detected in 64.2% of cases(54/84), and this was significantly correlated with tumor stage(P = 0.023) and size(P = 0.043). HIF-1α protein expression was correlated significantly with MTH-1 expression(R = 0.640; P < 0.01) in human CRC tissues. Hypoxic stress induced m RNA and protein expression of MTH-1 in SW480 and HT-29 cells. Inhibition of HIF-1α by si RNA decreased the expression of MTH-1 and led to the accumulation of 8-oxo-d GTP in SW480 and HT-29 cells. In the in vivo xenograft tumor model, expression of MTH-1 was decreased in the HIF-1α si RNA group, and the tumor volume was much smaller than that in the mock si RNA group.CONCLUSION: MTH-1 expression in CRC cells was upregulated via HIF-1α in response to hypoxic stress, emphasizing the crucial role of HIF-1α-induced MTH-1 in tumor growth.
基金supported by grants-in-aid from the 333 Project(No.2007099)Project of the Health Department,Jiangsu Province,China(H200523)
文摘BACKGROUND:Hepatic hypoxia-inducible factor-1(HIF-1) is activated in the progression of hepatocellular carcinoma (HCC).This study aimed to investigate the dynamic alterations of HIF-1αand its gene expression so as to explore the relationship between HIF-1αexpression and hepatocarcinogenesis at the early stage of HCC. METHODS:A hepatoma model was made with 2-fluorenyl- acetamide(2-FAA)in male Sprague-Dawley rats.Morphological changes of rat hepatocytes were assessed pathologically (HE staining).The dynamic expression of hepatic and circulating HIF-1αwas quantitatively analyzed by ELISA. The gene fragments of hepatic HIF-1αmRNA were amplified by RT-PCR and confirmed by sequencing.The cellular distribution of hepatic HIF-1αexpression was confirmed by immunohistochemistry. RESULTS:Histological examination confirmed granulelike degeneration to atypical hyperplasia and HCC development in rat hepatocytes and progressive increases in the levels of hepatic and circulating HIF-1αand its gene expression during the course.The levels of HIF-1α expression in the liver and blood of rats with hepatoma were significantly higher than those in normal ratsand those with degeneration.Immunohistochemical analysis confirmed the positive expression and hepatocyte distribution of HIF-1αin the development of rat hepatoma. A positive relationship was found between HIF-1α expression in the liver and blood(P<0.01). CONCLUSIONS:The above observations support the hypothesis that the overexpression of HIF-1αand its gene are closely associated with the malignant transformation of hepatocytes and play an important role at the stage of hepatocarcinogenesis.
文摘BACKGROUND： Neural stem cell （NSC） survival is closely associated with cell apoptosis in ischemic-hypoxic regions following transplantation. Numerous studies have revealed that X-box binding protein 1 （XBP1） is a transcription factor during endoplasmic reticulum unfolded protein response and is essential for cell survival, differentiation, and anti-apoptotic effects. OBJECTIVE： To determine the effects of the XBP1 gene on NSC proliferation and apoptosis under hypoxic conditions following XBP1 gene transfection into rat embryonic hippocampal NSCs using recombinant adenovirus vector. DESIGN, TIME AND SETTING： In vitro experiments were performed at the Laboratory of Cell Biology of Jilin University and Laboratory of Proteomics, Department of Neurology, Jilin University China from September 2008 to November 2009. MATERIALS： Recombinant adenovirus package XBP1 gene and Ad-XBPl-enhanced green fluorescent protein plasmid （Guangzhou Easywin BioMed Technology, China）, rabbit anti-XBP1 and its target gene estrogen receptor degradation-enhancing a-mannosidase-like protein （EDEM） glucose-regulated protein 78 （GRP78）, anti-apoptotic molecule Bcl-2 and proapoptotic molecule Bax polyclonal antibody （Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA）, and COCI2 （Sigma, St. Louis, MO, USA） were used in the present study. METHODS： Hippocampi from embryonic, Sprague Dawley rats on gestational day 16 were harvested for NSC isolation and cloning, followed by immunofluorescence for Nestin and sub-culturing. The recombinant adenovirus Ad-XBPl-enhanced green fluorescent protein plasmid was transfected into rat embryonic hippocampal NSCs, and then CoCl2 was applied to induce hypoxia. MAIN OUTCOME MEASURES： Cell quantification and 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide colorimetric assay were utilized to detect proliferation in XBPl-transfected NSCs for 7 consecutive days. Western blot assay was utilized to quantify XBP1 GRP78, EDEM, Bcl-2, and Bax expression. Flow cytometry was used to measure apoptosis. RESULTS： NSC proliferation was significantly enhanced following XBP1 gene transfection （P 〈 0.05）. Under hypoxic conditions, GRP78, EDEM, and Bcl-2 levels increased, but Bax levels decreased. In addition, NSC apoptosis decreased following transfection （P 〈 0.05）. CONCLUSION： The XBP1 gene was successfully transfected into rat embryonic hippocampal NSCs using a recombinant adenovirus vector. NSC proliferation following transfection, as well as anti-apoptotic effects under hypoxia, was significantly increased.
