Neonatal hypoxic-ischemic encephalopathy(HIE)is a significant cause of disability in children.Improving brain function and accelerating neurological recovery may require a combination of neuroprotective and pro-regene...Neonatal hypoxic-ischemic encephalopathy(HIE)is a significant cause of disability in children.Improving brain function and accelerating neurological recovery may require a combination of neuroprotective and pro-regenerative treatments at different stages of HIE.While the first hours after the neonatal insult are the most critical period for neuroprotection,the existence of secondary and tertiary mechanisms of brain injury offers the possibility of preventing delayed neurodegeneration in the subsequent days,weeks,or months(Levison et al.,2022).展开更多
Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral ...Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral blood pressure.While NO is catalyzed by various nitric oxide synthase(NOS)isoforms,the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear.Therefore,this study aims to investigate the regu-latory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation.Methods:Forty healthy male Sprague–Dawley(SD)rats were randomly divided into four groups:Control group(NG-nitro-D-arginine methyl ester,D-NAME),L-NAME group(non-selective NOS inhibitor,NG-nitro-L-arginine methyl ester),AG group(in-ducible NOS inhibitor group,aminoguanidine),and 7-NI group(neurological NOS in-hibitor,7-nitroindazole).Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia[15%O2,2200 m a.sl.,582 mmHg(76.5 kPa),Xining,China]using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics in vivo.Serum NO concentra-tions and blood gas analysis were measured.Results:Under normoxia,mean arterial pressure and total peripheral vascular resist-ance were increased,and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups.During hypoxia,pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups.Conclusions:This compensatory mechanism activated by inducible NOS and en-dothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress.It plays a crucial role in alleviating hypoxia-induced pulmonary arte-rial hypertension.展开更多
Hypoxic pulmonary hypertension(HPH)is a pathophysiological state characterized by diverse clinical symptoms resulting from structural and functional changes in pulmonary vessels induced by hypoxic stimuli,leading to i...Hypoxic pulmonary hypertension(HPH)is a pathophysiological state characterized by diverse clinical symptoms resulting from structural and functional changes in pulmonary vessels induced by hypoxic stimuli,leading to increased pulmonary artery pressure.展开更多
The challenge of protecting the brain resides in the unique characteristics of neurons,as they are postmitotic,long-lived,excitable,and polarized cells with long and fragile axons and dendrites.The complexity of the m...The challenge of protecting the brain resides in the unique characteristics of neurons,as they are postmitotic,long-lived,excitable,and polarized cells with long and fragile axons and dendrites.The complexity of the multiple potential cell death pathways further complicates this issue.In addition,the immature brain is prone to a“cell death continuum,”which involves intricate molecular interconnections between cell death processes.展开更多
BACKGROUND Emerging evidence indicates that hypoxic preconditioning boosts the antioxidant and anti-apoptotic capacities of mesenchymal stem cell-derived exosomes;however,the specific mechanisms remain incompletely el...BACKGROUND Emerging evidence indicates that hypoxic preconditioning boosts the antioxidant and anti-apoptotic capacities of mesenchymal stem cell-derived exosomes;however,the specific mechanisms remain incompletely elucidated.This study explored the impact of hypoxia-preconditioned mesenchymal stem cell-derived exosomes(hypo-Exos)vs normoxic counterparts on the apoptotic response in cardiomyocytes triggered by oxidative stress.AIM To determine whether and how hypoxic preconditioning augments the cardioprotective efficacy of hypo-Exos against oxidative stress-induced cardiomyocyte apoptosis.METHODS H9C2 cardiomyocytes were treated with hydrogen peroxide(H2O2)to induce oxidative injury.Assessments of cell viability,oxidative biomarkers,and apoptotic activity were conducted to evaluate the therapeutic efficacy of hypo-Exos and normoxic counterparts.High-throughput sequencing was performed to identify potential target microRNAs(miRNAs).Luciferase reporter assays were conducted to confirm selected miRNAs binding to target genes.Hypo-Exos loaded with selected miRNAs antagomirs or negative controls were administered to H2O2-treated H9C2 cells to validate the downstream signaling pathways involved.RESULTS Hypo-Exos significantly enhanced cell viability,reduced oxidative stress,and inhibited apoptosis of cardiomyocytes.Hypoxic preconditioning significantly increased the expression of exosomal miR-486-5p,which directly targeted the phosphatase and tensin homolog.Additionally,hypo-Exos markedly activated the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)pathway.Moreover,deletion of miR-486-5p in hypo-Exos counteracted the anti-apoptotic effects and suppressed PI3K/Akt pathway activation.CONCLUSION Hypoxic preconditioning augments anti-apoptotic properties of exosomes,primarily via miR-486-5p upregulation,which mediates its function by modulating the phosphatase and tensin homolog/PI3K/Akt axis.展开更多
Pulmonary hypertension(PH)is a pulmonary vascular disease caused by multiple etiologies,characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure,which can lead to severe cardiova...Pulmonary hypertension(PH)is a pulmonary vascular disease caused by multiple etiologies,characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure,which can lead to severe cardiovascular complications.The third type of PH,hypoxic pulmonary hypertension(HPH)caused by chronic lung disease and/or hypoxia,has complex and incomplete pathological mechanism.Current clinical treatment for HPH primarily focus on alleviating symptoms,with limited effectiveness in improving pulmonary vascular remodeling(PVR).Recent studies by various scholars have indicated that certain traditional Chinese medicine(TCM)monomers,extracts,and formulations can inhibit multiple signaling pathways,thereby suppressing pulmonary vascular remodeling and demonstrating favorable efficacy against HPH.This article reviews the pathogenesis of HPH,including pulmonary arterial wall thickening,immune inflammation,and thrombogenesis,and discusses the latest research advancements regarding the pharmacodynamic mechanisms of TCM in treating HPH.展开更多
Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions....Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions.However,the effects of glutathione on fish under hypoxic stress remain poorly understood.This study aimed to investigate the impact of glutathione on gill tissue damage in fish under hypoxic stress and explore the underlying mechanisms.Methods Six experimental diets with varying glutathione concentrations.The actual glutathione levels in these diets,measured by high-performance liquid chromatography,were 0.00,145.95,291.90,437.85,583.80,and 729.75 mg/kg,respectively.Fish were fed these diets for 70 d,after which a 96-h hypoxic stress experiment was conducted.The experiment was set up with normoxic and hypoxic groups,in which the dissolved oxygen in the group was 6 mg/L,and that in the group was 1 mg/L.Results This research revealed that glutathione could enhance the growth performance and antioxidant capability of juvenile grass carp while mitigating the structural damage to gill tissues induced by hypoxia stress.Mechanistic investigations further indicated that glutathione mitigated hypoxia-induced oxidative injury in gill tissues and improved their antioxidant capacity.In addition,glutathione attenuated gill apoptosis induced by hypoxia stress.Glutathione also inhibited the initiation,nucleation,elongation,and degradation phases of autophagy,thereby attenuating hypoxia-induced gill autophagy.Moreover,glutathione was found to alleviate hypoxia-induced endoplasmic reticulum stress(ERS)in gills,a response potentially linked to the suppression of PERK,IRE1,and ATF6 signaling pathways.Finally,based on the ROS and PC contents in gill tissue,the optimum glutathione supplementation levels for juvenile grass carp under hypoxia stress were 437.10 and 495.00 mg/kg,respectively.Conclusions In conclusion,our experimental results demonstrated the effectiveness of glutathione in alleviating gill tissue damage caused by hypoxic stress.This study confirms the feasibility and effectiveness of dietary glutathione addition to alleviate hypoxic stress in fish.展开更多
Purpose: Normobaric hypoxia(NH) is a frequent strategy for training under hypoxic conditions that can be administered through different equipment, including face masks or hypoxic chambers/tents. Nonetheless, the versa...Purpose: Normobaric hypoxia(NH) is a frequent strategy for training under hypoxic conditions that can be administered through different equipment, including face masks or hypoxic chambers/tents. Nonetheless, the versatility of administration methods may influence the outcomes.Methods: Web of Science, Scopus, SPORTDiscus and Pub Med/MEDLINE were searched to identify studies assessing the effect of NH administered by face mask or chamber/tent equipment on maximal oxygen uptake( VO2max) after a training period. An overall meta-analysis and sub-analysis of total program session volume(low, moderate, high), participants' training level(trained, active, sedentary), and the severity of hypoxia(moderate, severe) were conducted to explore the effects of the NH-administration system.Results: Eighteen studies were included. Compared with normoxia, NH showed a moderate global improvement in VO2max(standardized mean difference [SMD] = 0.74;p = 0.06), favoring the chamber/tent(SMD = 1.30;p< 0.01) over the face mask. Sub-analysis showed a very large effect in support of the hypoxic chamber/tent among sedentary individuals and training programs with a high volume of sessions. Severe hypoxia did not yield conclusive findings in VO2max improvements, although the chamber/tent proved more effective(SMD = 1.42;p< 0.01) than the face mask under moderate hypoxia.Conclusions: Chambers/tents may slightly accentuate the benefit of NH on aerobic performance, particularly in participants with limited training experience following a high volume of sessions under moderate hypoxia.However, the variability of sub-analysis factors(session volume, participants' training level, and methodological approaches) between studies using each type of hypoxia-generating equipment may influence this result.展开更多
Exosomes derived from hypoxic endometrial epithelial cells are pivotal in cellular communication and tissue repair,offering new perspectives on reproductive health.This manuscript highlights the study by Zhang et al,w...Exosomes derived from hypoxic endometrial epithelial cells are pivotal in cellular communication and tissue repair,offering new perspectives on reproductive health.This manuscript highlights the study by Zhang et al,which investigates the effects of miR-214-5p and miR-21-5p in hypoxic cell-derived exosomes on human umbilical cord mesenchymal stem cells.The study reveals that low levels of these microRNAs activate the signal transducer and activator of transcription 3 signaling pathway,enhancing human umbilical cord mesenchymal stem cell migration and differentiation.These findings provide novel insights into therapeutic strategies for improving endometrial health and addressing infertility linked to thin endometrium.展开更多
BACKGROUND： It has been previously shown that hyperbaric oxygen may promote proliferation of neural stem cells and reduce death of endogenous neural stem cells （NSCs）. OBJECTIVE： To explore the effects of hyperbar...BACKGROUND： It has been previously shown that hyperbaric oxygen may promote proliferation of neural stem cells and reduce death of endogenous neural stem cells （NSCs）. OBJECTIVE： To explore the effects of hyperbaric oxygen on the differentiation of hypoxic/ischemic brain-derived NSCs into neuron-like cells and compare with high-concentration oxygen and high pressure. DESIGN, TIME AND SETTING： An in vitro contrast study, performed at Laboratory of Neurology, Central South University between January and May 2006. MATERIALS： A hyperbaric oxygen chamber （YLC 0.5/1A） was provided by Wuhan Shipping Design Research Institute; mouse anti-rat microtubule-associated protein 2 monoclonal antibody by Jingmei Company, Beijing; mouse anti-rat glial fibrillary acidic protein monoclonal antibody by Neo Markers, USA; mouse anti-rat galactocerebroside monoclonal antibody by Santa Cruz Biotechnology Inc., USA; and goat anti-mouse fluorescein isothiocyanate-labeled secondary antibody by Wuhan Boster Bioengineering Co., Ltd., China. METHODS： Brain-derived NSCs isolated from brain tissues of neonatal Sprague Dawley rats were cloned and passaged, and assigned into five groups： normal control, model, high-concentration oxygen, high pressure, and hyperbaric oxygen groups. Cells in the four groups, excluding the normal control group, were incubated in serum-containing DMEM/F12 culture medium. Hypoxic/ischemic models of NSCs were established in an incubator comprising 93% N2, 5% 002, and 2% 02. Thereafter, cells were continuously cultured as follows： compressed air （0.2 MPa, 1 hour, once a day） in the high pressure group, compressed air ＋ a minimum of 80% 02 in the hyperbaric oxygen group, and a minimum of 80% Q2 in the high-concentration oxygen group. Cells in the normal control and model groups were cultured as normal. MAIN OUTCOME MEASURES： At day 7 after culture, glial fibrillary acidic protein, microtubule-associated protein 2, and galactocerebroside immunofluorescence staining were examined to observe differentiation and calculate the percentage of NSCs differentiating into neuron-like cells or neuroglia-like cells. RESULTS： Neuron-like cells or neuroglia-like cells were visualized in all five groups. There were no significant differences in the percentage of differentiating cells between the hyperbaric oxygen group and the normal control group （P 〉 0.05）. The percentage of NSCs differentiating into neuron-like cells in the hyperbaric oxygen group was significantly greater than model, high-concentration oxygen, and high pressure groups; however, the percentage differentiating into neuroglia-like cells was significantly lower （P 〈 0.01 ）. CONCLUSION： Hyperbaric oxygen promotes the differentiation of brain-derived neural stem cells into neuron-like cells but inhibits differentiation into neuroglia-like cells. Furthermore, the efficacy of hyperbaric oxygen is superior to high-concentration oxygen and high pressure.展开更多
BACKGROUND: Hepatocyte apoptosis is a severe form of cell death after hepatic ischemia-reperfusion injury (HIRI), and its relief is an important issue in liver transplantation. Hypoxic preconditioning (HP) is consider...BACKGROUND: Hepatocyte apoptosis is a severe form of cell death after hepatic ischemia-reperfusion injury (HIRI), and its relief is an important issue in liver transplantation. Hypoxic preconditioning (HP) is considered to have protective effects on HIRI. This study was designed to explore the impact of HP on apoptosis and its possible mechanism during orthotopic liver autotransplantation. METHODS: A modified orthotopic liver autotransplantation model was used to simulate HIRI. Sprague-Dawley rats were randomly divided into normal control, autotransplantation (AT) and HP groups. The HP group was subjected to an 8% oxygen atmosphere for 90 minutes before surgery. At 1, 6 and 24 hours after surgery, the rats were killed and their liver tissue was sampled to assess the expression of Bcl-2 protein. The samples were subjected to blood chemistry study, morphological study under a light or transmission electron microscope, and quantitative study of mitochondria. RESULTS: The serum levels of ALT and AST in the HP group were lower than those in the AT group at 1, 6 and 24 hours after orthotopic liver autotransplantation (P < 0.05). Bcl-2 protein expression was increased in the HP group at each measurement point (P < 0.05). Light microscopy showed that hepatic injury in the AT group was much more severe than in the HP group. Hepatocytes in the AT group showed typical apoptosis signs under a transmission electron microscope. The ultrastructural appearance of hepatocytes in the HP group was much better than in the AT group, and the area, perimeter and diameter of the mitochondria were smaller in the HP group than in the AT group (P < 0.05). CONCLUSIONS: Hepatocytes sense and respond to decreased tissue oxygenation. Stimulation by HP relieves apoptosis by upregulating expression of Bcl-2 protein and its protection of mitochondria after orthotopic liver autotransplantation.展开更多
In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebr...In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition, the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and ＂crawling method＂, respectively. Compared with control group （cerebral ischemia-reperfusion without hypoxic preconditioning）, the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group （cerebral ischemiareperfusion with hypoxie preconditioning）, both P〈0.05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.展开更多
Previous studies have demonstrated the protective effect of hypoxic preconditioning on acute cerebral infarction, but the mechanisms underlying this protection remain unclear. To investigate the protective mechanisms ...Previous studies have demonstrated the protective effect of hypoxic preconditioning on acute cerebral infarction, but the mechanisms underlying this protection remain unclear. To investigate the protective mechanisms of hypoxic preconditioning in relation to its effects on angiogenesis, we in- duced a photochemical model of cerebral infarction in an inbred line of mice （BALB/c）. Mice were then exposed to hypoxic preconditioning 30 minutes prior to model establishment. Results showed significantly increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra at 24 and 72 hours post infarction, mainly in neurons and vascular endothelial cells. Hypoxic preconditioning increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra and the expression of vascular endothelial growth factor was positively related to that of CD31. Moreover, hypoxic preconditioning reduced the infarct volume and improved neu- rological function in mice. These findings indicate that the protective role of hypoxic preconditioning in acute cerebral infarction may possibly be due to an increase in expression of vascular endothelial growth factor and CD31 in the ischemic penumbra, which promoted angiogenesis.展开更多
Background： Vascular endothelial growth factor A （VEGFA） can induce endothelial cell proliferation, promote cell migration, and inhibit apoptosis. These processes play key roles in physiological blood vessel format...Background： Vascular endothelial growth factor A （VEGFA） can induce endothelial cell proliferation, promote cell migration, and inhibit apoptosis. These processes play key roles in physiological blood vessel formation and pathological angiogenesis. Methods： In this study, we examined VEGFA gene expression in the heart, liver, and kidney of Tibetan pigs （-I-P）, Yorkshire pigs that migrated to high altitudes （YH）, and Yorkshire pigs that lived at low altitudes （YL）. We used PCR and Sanger sequencing to screen for single nucleotide polymorphisms （SNPs） in 5＇-flanking DNA and exons of the VEGFA gene. Quantitative real-time PCR and western blots were used to measure expression levels and PCR products were sequenced. Results： Results showed that the VEGFA mRNA and protein expression in heart, liver and kidney of TP was higher than that in YH and YL. In addition, the mRNA sequence of the pig VEGFA gene was conserved among pig breeds, and only five SNPs were found in the 5＇-flanking region of the VEGFA gene, the allele frequency distributions of the 5 SNPs were not significantly different between the TP, Yorkshire （YL）, and Diannan small-ear （DN） pig populations. Conclusion： In conclusion, the Tibetan pig showed high tissues, which suggests that the VEGFA gene may play a levels of VEGFA gene expression in several hypoxic major functional role in hypoxic adaptation.展开更多
To investigate the effects of hypoxic exercise training on microRNA （miRNA） expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic s...To investigate the effects of hypoxic exercise training on microRNA （miRNA） expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic sedentary group （N, n=10） and a hypoxic exercise training group （H, n=10）. After four weeks, measurements were taken of body weight, body length, fat mass, serum lipid concentration, miRNAs differentially expressed in rat liver, and gene and protein expression levels of perexisome proliferator activated receptor a （PPARα）, fatty acid synthetase （FAS）, and carnitine palmitoyl transferase 1A （CPTIA） in rat liver. Body weight, Lee＇s index, fat mass, fat/weight ratio, and serum levels of total cholesterol （TC） and high density lipoprotein cholesterol （HDL-C） were all significantly lower in the H group than in the N group （P〈0.01）. Six miRNAs expressed significantly differently in the liver （P〈0.05）. Specifically, expression levels of miR-378b were significantly lower in the H group than in the N group （P〈0.05）. Compared with the normoxic sedentary group, hypoxic exercise training resulted in a lower ratio of FAS mRNA to CPTIA mRNA （P〈0.05）, as well as lower CPT1A protein levels （P〈0.01）, while a higher ratio of FAS to CPT1A protein levels （P〈0.01） was observed. In conclusion, hypoxic training may elevate the resistance of high fat diet induced obesity in rats by reducing the expression of miR-378b, and decrease the fatty acid mitochondrial oxidation in obese rat livers by decreasing the protein expression of CPTIA and increasing the protein expression ratio of FAS/CPTIA.展开更多
Hypoxic preconditioning refers to the exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that results in increased resistance to a subsequent episode of severe hypoxia/ischemia. In t...Hypoxic preconditioning refers to the exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that results in increased resistance to a subsequent episode of severe hypoxia/ischemia. In this article, we review recent research based on a mouse model of repeated exposure to autohypoxia. Pre-exposure markedly increases the tolerance to or protection against hypoxic insult, and preserves the cellular structure of the brain. Furthermore, the hippocampal activity amplitude and frequency of electroencephalogram, latency of cortical somatosensory-evoked potential and spinal somatosensory-evoked potential progressively decrease, while spatial learning and memory improve. In the brain, detrimental neurochemicals such as free radicals are down-regulated, while beneficial ones such as adenosine are up-regulated. Also, antihypoxia factor（s） and gene（s） are activated. We propose that the tolerance and protective effects depend on energy conservation and plasticity triggered by exposure to hypoxia via oxygen-sensing transduction pathways and hypoxia-inducible factor-initiated cascades. A potential path for further research is the development of devices and pharma-ceuticals acting on antihypoxia factor（s） and gene（s） for the prevention and treatment of hypoxia and related syndromes.展开更多
Background:Tibetan chickens,a unique native breed in the Qinghai-Tibet Plateau of China,possess a suite of adaptive features that enable them to tolerate the high-altitude hypoxic environment.Increasing evidence sugge...Background:Tibetan chickens,a unique native breed in the Qinghai-Tibet Plateau of China,possess a suite of adaptive features that enable them to tolerate the high-altitude hypoxic environment.Increasing evidence suggests that long non-coding RNAs(lncRNAs)and microRNAs(miRNAs)play roles in the hypoxic adaptation of high-altitude animals,although their exact involvement remains unclear.Results:This study aimed to elucidate the global landscape of mRNAs,lncRNAs,and miRNAs using transcriptome sequencing to construct a regulatory network of competing endogenous RNAs(ceRNAs)and thus provide insights into the hypoxic adaptation of Tibetan chicken embryos.In total,354 differentially expressed genes(DE genes),389 differentially expressed lncRNAs(DE lncRNAs),and 73 differentially expressed miRNAs(DE miRNAs)were identified between Tibetan chickens(TC)and control Chahua chickens(CH).GO and KEGG enrichment analysis revealed that several important DE miRNAs and their target DE lncRNAs and DE genes are involved in angiogenesis(including blood vessel development and blood circulation)and energy metabolism(including glucose,carbohydrate,and lipid metabolism).The ceRNA network was then constructed with the predicted DE gene-DE miRNA-DE lncRNA interactions,which further revealed the regulatory roles of these differentially expressed RNAs during hypoxic adaptation of Tibetan chickens.Conclusions:Analysis of transcriptomic data revealed several key candidate ceRNAs that may play high-priority roles in the hypoxic adaptation of Tibetan chickens by regulating angiogenesis and energy metabolism.These results provide insights into the molecular mechanisms of hypoxic adaptation regulatory networks from the perspective of coding and non-coding RNAs.展开更多
BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to profile gene expression patterns involved in hypoxic precondi...BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to profile gene expression patterns involved in hypoxic preconditioning and probable mechanism at the level of gene expression. METHODS: Hepatocytes were divided into 2 groups: control group and hypoxic preconditioning group. Biotinlabeled cRNA from the control group and the hypoxic preconditioning group was hybridized by oligonucleotide microarray. Genes that were significantly associated with hypoxic preconditioning were filtered, and validated at the level of transcript expression. RESULTS: Forty-three genes with significantly altered expression patterns were discovered and most of them had not been previously reported. Among these genes,genes encoding superoxide dismutase 2 (SOD2)and interleukin 10 (IL-10) in the hypoxic preconditioning group were confirmed to be up-regulated with real-time quantitative PCR. CONCLUSIONS: Many cytokines are involved in hypoxic preconditioning and protect hepatocytes from hypoxiareoxygenation injury, and the increase of oxygen freeradical scavengers and anti-inflammatory factors may play a key role in this phenomenon. Diverse signal pathways are probably involved.展开更多
Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy. However, the specific brain networks implicated in neonatal cases rema...Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy. However, the specific brain networks implicated in neonatal cases remain poorly understood. In this study, we recruited 14 termborn infants with mild hypoxic ischemic encephalopathy and 14 term-born infants with severe hypoxic ischemic encephalopathy from Changzhou Children's Hospital, China. Resting-state functional magnetic resonance imaging data showed efficient small-world organization in whole-brain networks in both the mild and severe hypoxic ischemic encephalopathy groups. However, compared with the mild hypoxic ischemic encephalopathy group, the severe hypoxic ischemic encephalopathy group exhibited decreased local efficiency and a low clustering coefficient. The distribution of hub regions in the functional networks had fewer nodes in the severe hypoxic ischemic encephalopathy group compared with the mild hypoxic ischemic encephalopathy group. Moreover, nodal efficiency was reduced in the left rolandic operculum, left supramarginal gyrus, bilateral superior temporal gyrus, and right middle temporal gyrus. These results suggest that the topological structure of the resting state functional network in children with severe hypoxic ischemic encephalopathy is clearly distinct from that in children with mild hypoxic ischemic encephalopathy, and may be associated with impaired language, motion, and cognition. These data indicate that it may be possible to make early predictions regarding brain development in children with severe hypoxic ischemic encephalopathy, enabling early interventions targeting brain function. This study was approved by the Regional Ethics Review Boards of the Changzhou Children's Hospital(approval No. 2013-001) on January 31, 2013. Informed consent was obtained from the family members of the children. The trial was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR1800016409) and the protocol version is 1.0.展开更多
The effects of hypoxic preconditioning (HP) on the functions of myocardial mitochondria and ATP content were studiedin the rat. Rats were exposed to a simulated altitude of 4000m (with a barometric pressure of 43 kPa)...The effects of hypoxic preconditioning (HP) on the functions of myocardial mitochondria and ATP content were studiedin the rat. Rats were exposed to a simulated altitude of 4000m (with a barometric pressure of 43 kPa) for 1d. The myocardialmitochondrial respiratory function was determined with the Clark type O2 electrode, mitochondrial membrane fluidity (MMF) wasassayed with fluorescence polarizative method, and the myocardial content of ATP, ADP and AMP were measured with high performance liquid chromatography. It was found that after the administration of HP, the ATP content was increased from 31.89±2.42/mg·g-1 to 60. 55±3.52/mg·g-1 (P<0.01 ), mitochondrial respiratory control rate (RGR) was increased from 1.84 ±0.58 to4. 55 ± 0. 32 (P<0.01), MMF was significantly increased (P< 0.05) and the activities of FO F1 -ATPase and Na+ -K+ -ATPasewere increased by 66% and 25%, respectively. It is concluded that HP is efficacious to improve myocardial energy metabolismthrough the mechanism of the increase of mitochondrial membrane fluidity and the improvement of mitochondrial respiratory function.展开更多
基金supported by Fundação de AmparoàPesquisa do Estado do Rio de Janeiro(FAPERJ,E-26/010.002160/2019,E-26/203.227/2017,E-260003/001177/2020,and E-26/201.279/2021)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq,313757/2020-8,311188/2023-0)(to PMPC).
文摘Neonatal hypoxic-ischemic encephalopathy(HIE)is a significant cause of disability in children.Improving brain function and accelerating neurological recovery may require a combination of neuroprotective and pro-regenerative treatments at different stages of HIE.While the first hours after the neonatal insult are the most critical period for neuroprotection,the existence of secondary and tertiary mechanisms of brain injury offers the possibility of preventing delayed neurodegeneration in the subsequent days,weeks,or months(Levison et al.,2022).
基金This work was supported by the National Natural Science Foundation of China(grant numbers 81560301 and 81160012)the Natural Science Foundation of Qinghai Province(grant number 2022-ZJ-905)‘2022 Qinghai Province Kunlun Talents High-end Innovation and Entrepreneurship Talents’Outstanding Talent Project.
文摘Background:Under hypoxia,exaggerated compensatory responses may lead to acute mountain sickness.The excessive vasodilatory effect of nitric oxide(NO)can lower the hypoxic pulmonary vasoconstriction(HPV)and peripheral blood pressure.While NO is catalyzed by various nitric oxide synthase(NOS)isoforms,the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear.Therefore,this study aims to investigate the regu-latory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation.Methods:Forty healthy male Sprague–Dawley(SD)rats were randomly divided into four groups:Control group(NG-nitro-D-arginine methyl ester,D-NAME),L-NAME group(non-selective NOS inhibitor,NG-nitro-L-arginine methyl ester),AG group(in-ducible NOS inhibitor group,aminoguanidine),and 7-NI group(neurological NOS in-hibitor,7-nitroindazole).Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia[15%O2,2200 m a.sl.,582 mmHg(76.5 kPa),Xining,China]using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics in vivo.Serum NO concentra-tions and blood gas analysis were measured.Results:Under normoxia,mean arterial pressure and total peripheral vascular resist-ance were increased,and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups.During hypoxia,pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups.Conclusions:This compensatory mechanism activated by inducible NOS and en-dothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress.It plays a crucial role in alleviating hypoxia-induced pulmonary arte-rial hypertension.
基金supported by General Program of the Natural Science Foundation of Hebei Province(No.H2024110033,China).
文摘Hypoxic pulmonary hypertension(HPH)is a pathophysiological state characterized by diverse clinical symptoms resulting from structural and functional changes in pulmonary vessels induced by hypoxic stimuli,leading to increased pulmonary artery pressure.
基金supported by grants from the Swiss National Science Foundation(310030-182332 and 310030L-208141)(to JP)。
文摘The challenge of protecting the brain resides in the unique characteristics of neurons,as they are postmitotic,long-lived,excitable,and polarized cells with long and fragile axons and dendrites.The complexity of the multiple potential cell death pathways further complicates this issue.In addition,the immature brain is prone to a“cell death continuum,”which involves intricate molecular interconnections between cell death processes.
基金the Precision Medical Center of Nanfang Hospital,with the informed consent of all participants and approved by the Medical Ethics Committee of the hospital(Approval No.NFEC-202110-K17-01).
文摘BACKGROUND Emerging evidence indicates that hypoxic preconditioning boosts the antioxidant and anti-apoptotic capacities of mesenchymal stem cell-derived exosomes;however,the specific mechanisms remain incompletely elucidated.This study explored the impact of hypoxia-preconditioned mesenchymal stem cell-derived exosomes(hypo-Exos)vs normoxic counterparts on the apoptotic response in cardiomyocytes triggered by oxidative stress.AIM To determine whether and how hypoxic preconditioning augments the cardioprotective efficacy of hypo-Exos against oxidative stress-induced cardiomyocyte apoptosis.METHODS H9C2 cardiomyocytes were treated with hydrogen peroxide(H2O2)to induce oxidative injury.Assessments of cell viability,oxidative biomarkers,and apoptotic activity were conducted to evaluate the therapeutic efficacy of hypo-Exos and normoxic counterparts.High-throughput sequencing was performed to identify potential target microRNAs(miRNAs).Luciferase reporter assays were conducted to confirm selected miRNAs binding to target genes.Hypo-Exos loaded with selected miRNAs antagomirs or negative controls were administered to H2O2-treated H9C2 cells to validate the downstream signaling pathways involved.RESULTS Hypo-Exos significantly enhanced cell viability,reduced oxidative stress,and inhibited apoptosis of cardiomyocytes.Hypoxic preconditioning significantly increased the expression of exosomal miR-486-5p,which directly targeted the phosphatase and tensin homolog.Additionally,hypo-Exos markedly activated the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)pathway.Moreover,deletion of miR-486-5p in hypo-Exos counteracted the anti-apoptotic effects and suppressed PI3K/Akt pathway activation.CONCLUSION Hypoxic preconditioning augments anti-apoptotic properties of exosomes,primarily via miR-486-5p upregulation,which mediates its function by modulating the phosphatase and tensin homolog/PI3K/Akt axis.
基金supported by the Special Funds for the Central Government to Guide Local Science and Technology Development(No.246Z7704G,China)National Natural Science Foundation of China(No.H2024110033,China).
文摘Pulmonary hypertension(PH)is a pulmonary vascular disease caused by multiple etiologies,characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure,which can lead to severe cardiovascular complications.The third type of PH,hypoxic pulmonary hypertension(HPH)caused by chronic lung disease and/or hypoxia,has complex and incomplete pathological mechanism.Current clinical treatment for HPH primarily focus on alleviating symptoms,with limited effectiveness in improving pulmonary vascular remodeling(PVR).Recent studies by various scholars have indicated that certain traditional Chinese medicine(TCM)monomers,extracts,and formulations can inhibit multiple signaling pathways,thereby suppressing pulmonary vascular remodeling and demonstrating favorable efficacy against HPH.This article reviews the pathogenesis of HPH,including pulmonary arterial wall thickening,immune inflammation,and thrombogenesis,and discusses the latest research advancements regarding the pharmacodynamic mechanisms of TCM in treating HPH.
基金financially supported by the Sichuan Science and Technology Program(2024YFNH0016,2024NSFSC2072)the earmarked fund for CARS(CARS-45)+2 种基金the National Science Fund for Distinguished Young Scholars of China(32425056)the National Key Research and Development Program of China(2023YFD2400600)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15)。
文摘Background Environmental hypoxia is a common phenomenon in aquaculture,which causes gill tissue injury in fish.Glutathione(GSH)is a vital antioxidant in animal tissues,and its levels decrease under hypoxic conditions.However,the effects of glutathione on fish under hypoxic stress remain poorly understood.This study aimed to investigate the impact of glutathione on gill tissue damage in fish under hypoxic stress and explore the underlying mechanisms.Methods Six experimental diets with varying glutathione concentrations.The actual glutathione levels in these diets,measured by high-performance liquid chromatography,were 0.00,145.95,291.90,437.85,583.80,and 729.75 mg/kg,respectively.Fish were fed these diets for 70 d,after which a 96-h hypoxic stress experiment was conducted.The experiment was set up with normoxic and hypoxic groups,in which the dissolved oxygen in the group was 6 mg/L,and that in the group was 1 mg/L.Results This research revealed that glutathione could enhance the growth performance and antioxidant capability of juvenile grass carp while mitigating the structural damage to gill tissues induced by hypoxia stress.Mechanistic investigations further indicated that glutathione mitigated hypoxia-induced oxidative injury in gill tissues and improved their antioxidant capacity.In addition,glutathione attenuated gill apoptosis induced by hypoxia stress.Glutathione also inhibited the initiation,nucleation,elongation,and degradation phases of autophagy,thereby attenuating hypoxia-induced gill autophagy.Moreover,glutathione was found to alleviate hypoxia-induced endoplasmic reticulum stress(ERS)in gills,a response potentially linked to the suppression of PERK,IRE1,and ATF6 signaling pathways.Finally,based on the ROS and PC contents in gill tissue,the optimum glutathione supplementation levels for juvenile grass carp under hypoxia stress were 437.10 and 495.00 mg/kg,respectively.Conclusions In conclusion,our experimental results demonstrated the effectiveness of glutathione in alleviating gill tissue damage caused by hypoxic stress.This study confirms the feasibility and effectiveness of dietary glutathione addition to alleviate hypoxic stress in fish.
基金supported by the Andalusian FEDER Operational Program [B-CTS-374-UGR20 and C-SEJ-015-UGR23]the Spanish Ministry of Science,Innovation and Universities [PGC2018-097388-BI00-MCI/AEI/FEDER,UE]。
文摘Purpose: Normobaric hypoxia(NH) is a frequent strategy for training under hypoxic conditions that can be administered through different equipment, including face masks or hypoxic chambers/tents. Nonetheless, the versatility of administration methods may influence the outcomes.Methods: Web of Science, Scopus, SPORTDiscus and Pub Med/MEDLINE were searched to identify studies assessing the effect of NH administered by face mask or chamber/tent equipment on maximal oxygen uptake( VO2max) after a training period. An overall meta-analysis and sub-analysis of total program session volume(low, moderate, high), participants' training level(trained, active, sedentary), and the severity of hypoxia(moderate, severe) were conducted to explore the effects of the NH-administration system.Results: Eighteen studies were included. Compared with normoxia, NH showed a moderate global improvement in VO2max(standardized mean difference [SMD] = 0.74;p = 0.06), favoring the chamber/tent(SMD = 1.30;p< 0.01) over the face mask. Sub-analysis showed a very large effect in support of the hypoxic chamber/tent among sedentary individuals and training programs with a high volume of sessions. Severe hypoxia did not yield conclusive findings in VO2max improvements, although the chamber/tent proved more effective(SMD = 1.42;p< 0.01) than the face mask under moderate hypoxia.Conclusions: Chambers/tents may slightly accentuate the benefit of NH on aerobic performance, particularly in participants with limited training experience following a high volume of sessions under moderate hypoxia.However, the variability of sub-analysis factors(session volume, participants' training level, and methodological approaches) between studies using each type of hypoxia-generating equipment may influence this result.
基金the National Natural Science Foundation of China,No.82170406 and No.81970238the Royal Society United Kingdom,No.IEC\NSFC\201094.
文摘Exosomes derived from hypoxic endometrial epithelial cells are pivotal in cellular communication and tissue repair,offering new perspectives on reproductive health.This manuscript highlights the study by Zhang et al,which investigates the effects of miR-214-5p and miR-21-5p in hypoxic cell-derived exosomes on human umbilical cord mesenchymal stem cells.The study reveals that low levels of these microRNAs activate the signal transducer and activator of transcription 3 signaling pathway,enhancing human umbilical cord mesenchymal stem cell migration and differentiation.These findings provide novel insights into therapeutic strategies for improving endometrial health and addressing infertility linked to thin endometrium.
文摘BACKGROUND： It has been previously shown that hyperbaric oxygen may promote proliferation of neural stem cells and reduce death of endogenous neural stem cells （NSCs）. OBJECTIVE： To explore the effects of hyperbaric oxygen on the differentiation of hypoxic/ischemic brain-derived NSCs into neuron-like cells and compare with high-concentration oxygen and high pressure. DESIGN, TIME AND SETTING： An in vitro contrast study, performed at Laboratory of Neurology, Central South University between January and May 2006. MATERIALS： A hyperbaric oxygen chamber （YLC 0.5/1A） was provided by Wuhan Shipping Design Research Institute; mouse anti-rat microtubule-associated protein 2 monoclonal antibody by Jingmei Company, Beijing; mouse anti-rat glial fibrillary acidic protein monoclonal antibody by Neo Markers, USA; mouse anti-rat galactocerebroside monoclonal antibody by Santa Cruz Biotechnology Inc., USA; and goat anti-mouse fluorescein isothiocyanate-labeled secondary antibody by Wuhan Boster Bioengineering Co., Ltd., China. METHODS： Brain-derived NSCs isolated from brain tissues of neonatal Sprague Dawley rats were cloned and passaged, and assigned into five groups： normal control, model, high-concentration oxygen, high pressure, and hyperbaric oxygen groups. Cells in the four groups, excluding the normal control group, were incubated in serum-containing DMEM/F12 culture medium. Hypoxic/ischemic models of NSCs were established in an incubator comprising 93% N2, 5% 002, and 2% 02. Thereafter, cells were continuously cultured as follows： compressed air （0.2 MPa, 1 hour, once a day） in the high pressure group, compressed air ＋ a minimum of 80% 02 in the hyperbaric oxygen group, and a minimum of 80% Q2 in the high-concentration oxygen group. Cells in the normal control and model groups were cultured as normal. MAIN OUTCOME MEASURES： At day 7 after culture, glial fibrillary acidic protein, microtubule-associated protein 2, and galactocerebroside immunofluorescence staining were examined to observe differentiation and calculate the percentage of NSCs differentiating into neuron-like cells or neuroglia-like cells. RESULTS： Neuron-like cells or neuroglia-like cells were visualized in all five groups. There were no significant differences in the percentage of differentiating cells between the hyperbaric oxygen group and the normal control group （P 〉 0.05）. The percentage of NSCs differentiating into neuron-like cells in the hyperbaric oxygen group was significantly greater than model, high-concentration oxygen, and high pressure groups; however, the percentage differentiating into neuroglia-like cells was significantly lower （P 〈 0.01 ）. CONCLUSION： Hyperbaric oxygen promotes the differentiation of brain-derived neural stem cells into neuron-like cells but inhibits differentiation into neuroglia-like cells. Furthermore, the efficacy of hyperbaric oxygen is superior to high-concentration oxygen and high pressure.
基金supported by grants from the Health Bureau(H200770)Technology Bureau(BS2005038)of Jiangsu Province,China
文摘BACKGROUND: Hepatocyte apoptosis is a severe form of cell death after hepatic ischemia-reperfusion injury (HIRI), and its relief is an important issue in liver transplantation. Hypoxic preconditioning (HP) is considered to have protective effects on HIRI. This study was designed to explore the impact of HP on apoptosis and its possible mechanism during orthotopic liver autotransplantation. METHODS: A modified orthotopic liver autotransplantation model was used to simulate HIRI. Sprague-Dawley rats were randomly divided into normal control, autotransplantation (AT) and HP groups. The HP group was subjected to an 8% oxygen atmosphere for 90 minutes before surgery. At 1, 6 and 24 hours after surgery, the rats were killed and their liver tissue was sampled to assess the expression of Bcl-2 protein. The samples were subjected to blood chemistry study, morphological study under a light or transmission electron microscope, and quantitative study of mitochondria. RESULTS: The serum levels of ALT and AST in the HP group were lower than those in the AT group at 1, 6 and 24 hours after orthotopic liver autotransplantation (P < 0.05). Bcl-2 protein expression was increased in the HP group at each measurement point (P < 0.05). Light microscopy showed that hepatic injury in the AT group was much more severe than in the HP group. Hepatocytes in the AT group showed typical apoptosis signs under a transmission electron microscope. The ultrastructural appearance of hepatocytes in the HP group was much better than in the AT group, and the area, perimeter and diameter of the mitochondria were smaller in the HP group than in the AT group (P < 0.05). CONCLUSIONS: Hepatocytes sense and respond to decreased tissue oxygenation. Stimulation by HP relieves apoptosis by upregulating expression of Bcl-2 protein and its protection of mitochondria after orthotopic liver autotransplantation.
文摘In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition, the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and ＂crawling method＂, respectively. Compared with control group （cerebral ischemia-reperfusion without hypoxic preconditioning）, the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group （cerebral ischemiareperfusion with hypoxie preconditioning）, both P〈0.05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.
基金supported by the National Natural Science Foundation of China,No.30870854the Natural Science Foundation of Beijing,No.7111003the Natural Science Foundation of Shandong Province,No.ZR2010HM029
文摘Previous studies have demonstrated the protective effect of hypoxic preconditioning on acute cerebral infarction, but the mechanisms underlying this protection remain unclear. To investigate the protective mechanisms of hypoxic preconditioning in relation to its effects on angiogenesis, we in- duced a photochemical model of cerebral infarction in an inbred line of mice （BALB/c）. Mice were then exposed to hypoxic preconditioning 30 minutes prior to model establishment. Results showed significantly increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra at 24 and 72 hours post infarction, mainly in neurons and vascular endothelial cells. Hypoxic preconditioning increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra and the expression of vascular endothelial growth factor was positively related to that of CD31. Moreover, hypoxic preconditioning reduced the infarct volume and improved neu- rological function in mice. These findings indicate that the protective role of hypoxic preconditioning in acute cerebral infarction may possibly be due to an increase in expression of vascular endothelial growth factor and CD31 in the ischemic penumbra, which promoted angiogenesis.
基金supported by the National Major Special Project on New Varieties Cultivation for Transgenic Organisms (2016ZX08009-003-006)the National Key Technology R&D Program (2012BAD03B03)the Program for Changjiang Scholar and Innovation Research Team in University (IRT1191)
文摘Background： Vascular endothelial growth factor A （VEGFA） can induce endothelial cell proliferation, promote cell migration, and inhibit apoptosis. These processes play key roles in physiological blood vessel formation and pathological angiogenesis. Methods： In this study, we examined VEGFA gene expression in the heart, liver, and kidney of Tibetan pigs （-I-P）, Yorkshire pigs that migrated to high altitudes （YH）, and Yorkshire pigs that lived at low altitudes （YL）. We used PCR and Sanger sequencing to screen for single nucleotide polymorphisms （SNPs） in 5＇-flanking DNA and exons of the VEGFA gene. Quantitative real-time PCR and western blots were used to measure expression levels and PCR products were sequenced. Results： Results showed that the VEGFA mRNA and protein expression in heart, liver and kidney of TP was higher than that in YH and YL. In addition, the mRNA sequence of the pig VEGFA gene was conserved among pig breeds, and only five SNPs were found in the 5＇-flanking region of the VEGFA gene, the allele frequency distributions of the 5 SNPs were not significantly different between the TP, Yorkshire （YL）, and Diannan small-ear （DN） pig populations. Conclusion： In conclusion, the Tibetan pig showed high tissues, which suggests that the VEGFA gene may play a levels of VEGFA gene expression in several hypoxic major functional role in hypoxic adaptation.
基金Project supported by the Science Foundation for the Youth of China Institute of Sport Science （CISS） （No. 13-19）
文摘To investigate the effects of hypoxic exercise training on microRNA （miRNA） expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic sedentary group （N, n=10） and a hypoxic exercise training group （H, n=10）. After four weeks, measurements were taken of body weight, body length, fat mass, serum lipid concentration, miRNAs differentially expressed in rat liver, and gene and protein expression levels of perexisome proliferator activated receptor a （PPARα）, fatty acid synthetase （FAS）, and carnitine palmitoyl transferase 1A （CPTIA） in rat liver. Body weight, Lee＇s index, fat mass, fat/weight ratio, and serum levels of total cholesterol （TC） and high density lipoprotein cholesterol （HDL-C） were all significantly lower in the H group than in the N group （P〈0.01）. Six miRNAs expressed significantly differently in the liver （P〈0.05）. Specifically, expression levels of miR-378b were significantly lower in the H group than in the N group （P〈0.05）. Compared with the normoxic sedentary group, hypoxic exercise training resulted in a lower ratio of FAS mRNA to CPTIA mRNA （P〈0.05）, as well as lower CPT1A protein levels （P〈0.01）, while a higher ratio of FAS to CPT1A protein levels （P〈0.01） was observed. In conclusion, hypoxic training may elevate the resistance of high fat diet induced obesity in rats by reducing the expression of miR-378b, and decrease the fatty acid mitochondrial oxidation in obese rat livers by decreasing the protein expression of CPTIA and increasing the protein expression ratio of FAS/CPTIA.
基金supported by grants from the National Natural Science Foundation of China (3967087, 81060212, and 81160244)the Beijing Natural Science Foundation (7962009)+2 种基金the China Postdoctoral Science Foundation (20080430851)the Science Foundation of Shandong Province, China (ZR2010HM029)the Inner Mongolia Science Foundation (2010BS1104)
文摘Hypoxic preconditioning refers to the exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that results in increased resistance to a subsequent episode of severe hypoxia/ischemia. In this article, we review recent research based on a mouse model of repeated exposure to autohypoxia. Pre-exposure markedly increases the tolerance to or protection against hypoxic insult, and preserves the cellular structure of the brain. Furthermore, the hippocampal activity amplitude and frequency of electroencephalogram, latency of cortical somatosensory-evoked potential and spinal somatosensory-evoked potential progressively decrease, while spatial learning and memory improve. In the brain, detrimental neurochemicals such as free radicals are down-regulated, while beneficial ones such as adenosine are up-regulated. Also, antihypoxia factor（s） and gene（s） are activated. We propose that the tolerance and protective effects depend on energy conservation and plasticity triggered by exposure to hypoxia via oxygen-sensing transduction pathways and hypoxia-inducible factor-initiated cascades. A potential path for further research is the development of devices and pharma-ceuticals acting on antihypoxia factor（s） and gene（s） for the prevention and treatment of hypoxia and related syndromes.
基金supported by the National Natural Science Foundation of China(31972532)the China Agricultural Research System(CARS-40-K05)the Innovation Base Cu。
文摘Background:Tibetan chickens,a unique native breed in the Qinghai-Tibet Plateau of China,possess a suite of adaptive features that enable them to tolerate the high-altitude hypoxic environment.Increasing evidence suggests that long non-coding RNAs(lncRNAs)and microRNAs(miRNAs)play roles in the hypoxic adaptation of high-altitude animals,although their exact involvement remains unclear.Results:This study aimed to elucidate the global landscape of mRNAs,lncRNAs,and miRNAs using transcriptome sequencing to construct a regulatory network of competing endogenous RNAs(ceRNAs)and thus provide insights into the hypoxic adaptation of Tibetan chicken embryos.In total,354 differentially expressed genes(DE genes),389 differentially expressed lncRNAs(DE lncRNAs),and 73 differentially expressed miRNAs(DE miRNAs)were identified between Tibetan chickens(TC)and control Chahua chickens(CH).GO and KEGG enrichment analysis revealed that several important DE miRNAs and their target DE lncRNAs and DE genes are involved in angiogenesis(including blood vessel development and blood circulation)and energy metabolism(including glucose,carbohydrate,and lipid metabolism).The ceRNA network was then constructed with the predicted DE gene-DE miRNA-DE lncRNA interactions,which further revealed the regulatory roles of these differentially expressed RNAs during hypoxic adaptation of Tibetan chickens.Conclusions:Analysis of transcriptomic data revealed several key candidate ceRNAs that may play high-priority roles in the hypoxic adaptation of Tibetan chickens by regulating angiogenesis and energy metabolism.These results provide insights into the molecular mechanisms of hypoxic adaptation regulatory networks from the perspective of coding and non-coding RNAs.
基金This study was supported by a grant from Shanghai Technology and Science Commission Foundation (No. 024107010).
文摘BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to profile gene expression patterns involved in hypoxic preconditioning and probable mechanism at the level of gene expression. METHODS: Hepatocytes were divided into 2 groups: control group and hypoxic preconditioning group. Biotinlabeled cRNA from the control group and the hypoxic preconditioning group was hybridized by oligonucleotide microarray. Genes that were significantly associated with hypoxic preconditioning were filtered, and validated at the level of transcript expression. RESULTS: Forty-three genes with significantly altered expression patterns were discovered and most of them had not been previously reported. Among these genes,genes encoding superoxide dismutase 2 (SOD2)and interleukin 10 (IL-10) in the hypoxic preconditioning group were confirmed to be up-regulated with real-time quantitative PCR. CONCLUSIONS: Many cytokines are involved in hypoxic preconditioning and protect hepatocytes from hypoxiareoxygenation injury, and the increase of oxygen freeradical scavengers and anti-inflammatory factors may play a key role in this phenomenon. Diverse signal pathways are probably involved.
基金supported by the Jiangsu Maternal and Child Health Research Project of China,No.F201612(to HXL)Changzhou Science and Technology Support Plan of China,No.CE20165027(to HXL)+1 种基金Changzhou City Planning Commission Major Science and Technology Projects of China,No.ZD201515(to HXL)Changzhou High Level Training Fund for Health Professionals of China,No.2016CZBJ028(to HXL)
文摘Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy. However, the specific brain networks implicated in neonatal cases remain poorly understood. In this study, we recruited 14 termborn infants with mild hypoxic ischemic encephalopathy and 14 term-born infants with severe hypoxic ischemic encephalopathy from Changzhou Children's Hospital, China. Resting-state functional magnetic resonance imaging data showed efficient small-world organization in whole-brain networks in both the mild and severe hypoxic ischemic encephalopathy groups. However, compared with the mild hypoxic ischemic encephalopathy group, the severe hypoxic ischemic encephalopathy group exhibited decreased local efficiency and a low clustering coefficient. The distribution of hub regions in the functional networks had fewer nodes in the severe hypoxic ischemic encephalopathy group compared with the mild hypoxic ischemic encephalopathy group. Moreover, nodal efficiency was reduced in the left rolandic operculum, left supramarginal gyrus, bilateral superior temporal gyrus, and right middle temporal gyrus. These results suggest that the topological structure of the resting state functional network in children with severe hypoxic ischemic encephalopathy is clearly distinct from that in children with mild hypoxic ischemic encephalopathy, and may be associated with impaired language, motion, and cognition. These data indicate that it may be possible to make early predictions regarding brain development in children with severe hypoxic ischemic encephalopathy, enabling early interventions targeting brain function. This study was approved by the Regional Ethics Review Boards of the Changzhou Children's Hospital(approval No. 2013-001) on January 31, 2013. Informed consent was obtained from the family members of the children. The trial was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR1800016409) and the protocol version is 1.0.
文摘The effects of hypoxic preconditioning (HP) on the functions of myocardial mitochondria and ATP content were studiedin the rat. Rats were exposed to a simulated altitude of 4000m (with a barometric pressure of 43 kPa) for 1d. The myocardialmitochondrial respiratory function was determined with the Clark type O2 electrode, mitochondrial membrane fluidity (MMF) wasassayed with fluorescence polarizative method, and the myocardial content of ATP, ADP and AMP were measured with high performance liquid chromatography. It was found that after the administration of HP, the ATP content was increased from 31.89±2.42/mg·g-1 to 60. 55±3.52/mg·g-1 (P<0.01 ), mitochondrial respiratory control rate (RGR) was increased from 1.84 ±0.58 to4. 55 ± 0. 32 (P<0.01), MMF was significantly increased (P< 0.05) and the activities of FO F1 -ATPase and Na+ -K+ -ATPasewere increased by 66% and 25%, respectively. It is concluded that HP is efficacious to improve myocardial energy metabolismthrough the mechanism of the increase of mitochondrial membrane fluidity and the improvement of mitochondrial respiratory function.
