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
The role of the hypoxia-inducible factor(HIF)subunits 1α and 2α in response to hypoxia is well established in lungepithelial cells,whereas little is known about HIF-3α with respect to transcriptional and translatio...The role of the hypoxia-inducible factor(HIF)subunits 1α and 2α in response to hypoxia is well established in lungepithelial cells,whereas little is known about HIF-3α with respect to transcriptional and translational regulation by hy-poxia.HIF-3α and HIF-1α are two similar but distinct basic helix-loop-helix-PAS proteins,which have been postulatedto activate hypoxia responsive genes in response to hypoxia.Here,we used quantitative real time RT-PCR and immu-noblotting to determine the activation of HIF-3α vs.HIF-1α by hypoxia.HIF-3α was strongly induced by hypoxia(1%O_2)both at the level of protein and mRNA due to an increase in protein stability and transcriptional activation,whereasHIF-1α protein and mRNA levels enhanced transiently and then decreased because of a reduction in its mRNA stabilityin A549 cells,as measured on mRNA and protein levels.Interestingly,HIF-3α and HIF-1α exhibited strikingly similarresponses to a variety of activating or inhibitory pharmacological agents.These results demonstrate that HIF-3α is ex-pressed abundantly in lung epithelial cells,and that the transcriptional induction of HIF-3α plays an important role in theresponse to hypoxia in vitro.Our findings suggest that HIF-3α,as a member of the HIF system,is complementary ratherthan redundant to HIF-1α induction in protection against hypoxic damage in alveolar epithelial cells.展开更多
DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-bu...DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-butylphthalide action by various means.We used hydrogen peroxide to induce injury to PC12cells and RAW264.7 cells to mimic neuronal oxidative stress injury in stroke in vitro and examined the effects of DI-3-n-butylphthalide.We found that DI-3-nbutylphthalide pretreatment markedly inhibited the reduction in viability and reactive oxygen species production in PC12 cells caused by hydrogen peroxide and inhibited cell apoptosis.Furthermore,DI-3-n-butylphthalide pretreatment inhibited the expression of the pro-apoptotic genes Bax and Bnip3.DI-3-nbutylphthalide also promoted ubiquitination and degradation of hypoxia inducible factor 1α,the key transcription factor that regulates Bax and Bnip3 genes.These findings suggest that DI-3-n-butylphthalide exhibits a neuroprotective effect on stroke by promoting hypoxia inducible factor-1α ubiquitination and degradation and inhibiting cell apoptosis.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a malignant tumor that occurs in the liver.Its onset is latent,and it shows high heterogeneity and can readily experience intrahepatic metastasis or systemic metastasis,which...BACKGROUND Hepatocellular carcinoma(HCC)is a malignant tumor that occurs in the liver.Its onset is latent,and it shows high heterogeneity and can readily experience intrahepatic metastasis or systemic metastasis,which seriously affects patients’quality of life.Numerous studies have shown that hypoxia inducible factor1α(HIF-1α)plays a significant role in the occurrence and development of tumors,as it promotes the formation of intratumoral vessels and plays a key role in their metastasis and invasion.Some studies have reported that caspase-3,which is induced by various factors,is involved in the apoptosis of tumor cells.AIM To investigate the expression of caspase-3 and HIF-1αand their relationship to the prognosis of patients with primary HCC complicated by pathological changes of hemorrhage and necrosis.METHODS A total of 88 patients with HCC complicated by pathological changes of hemorrhage and necrosis who were treated at our hospital from January 2017 to December 2019 were selected.The expression of caspase-3 and HIF-1αin HCC and paracancerous tissues from these patients was assessed.RESULTS The positive expression rate of caspase-3 in HCC tissues was 27.27%,which was significantly lower than that in the paracancerous tissues(P<0.05),while the positive expression rate of HIF-1αwas 72.73%,which was significantly higher than that in the paracancerous tissues(P<0.05).The positive expression rates for caspase-3 in tumor node metastasis(TNM)stage III and lymph node metastasis tissues were 2.78%and 2.50%,respectively,which were significantly lower than those in TNM stage I-II and non-lymph node metastasis tissues(P<0.05).The positive expression rates of HIF-1αin TNM stage III,lymph node metastasis,and portal vein tumor thrombus tissues were 86.11%,87.50%,and 88.00%,respectively,and these values were significantly higher than those in TNM stage I-II,non-lymph node metastasis,and portal vein tumor thrombus tissues(P<0.05).The expression of caspase-3 and HIF-1αin HCC tissues were negatively correlated(rs=−0.426,P<0.05).The median overall survival time of HCC patients was 18.90 mo(95%CI:17.20–19.91).The results of the Cox proportional risk regression model analysis showed that TNM stage,portal vein tumor thrombus,lymph node metastasis,caspase-3 expression,and HIF-1αexpression were the factors influencing patient prognosis(P<0.05).CONCLUSION The expression of caspase-3 decreases and HIF-1αincreases in HCC tissues complicated by pathological changes of hemorrhage and necrosis,and these are related to clinicopathological features and prognosis.展开更多
Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α...Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α present antileishmanial properties.Methods:The leishmanicidal effect of drugs was evaluated in mouse macrophages and Balb/c mouse model for cutaneous leishmaniosis.Results:Resveratrol and CdCl_2 reduced the parasite load [IC50,(27.3±2.25) μM and(24.8±0.95) μM,respectively].The IC50 value of echinomycin was(22.7±7.36) nM and mimosine did not alter the parasite load in primary macrophages.The macrophage viability IC50 values for resveratrol,echinomycin and CdCl_2 and mimosine were >40 μM,>100 nM,> 200 μM and>2 000 μM,respectively.In vivo no differences between cutaneous lesions from control,resveratrol-and echinomycin-treated Balb/c mice were detected.Conclusions:Resveratrol,echinomycin and CdCl_2 reduce parasite survival in vitro.The HIF-1α targeting pharmacological drugs require further study to more fully determine their anti-Leishmania potential and their role in therapeutic strategies.展开更多
BACKGROUND The occurrence and development of acute liver failure(ALF)is closely related to a series of inflammatory reactions,such as the production of reactive oxygen species(ROS).Hypoxia inducible factor 1α(HIF-1α...BACKGROUND The occurrence and development of acute liver failure(ALF)is closely related to a series of inflammatory reactions,such as the production of reactive oxygen species(ROS).Hypoxia inducible factor 1α(HIF-1α)is a key factor that regulates oxygen homeostasis and redox,and the stability of HIF-1αis related to the ROS level regulated by Sirtuin(Sirt)family.The activation of Sirt1 will lead to a powerful antioxidant defense system and therapeutic effects in liver disease.However,little is known about the relationship between HIF-1αand Sirt1 in the process of ALF and the molecular mechanism.AIM To investigate whether HIF-1αmay be a target of Sirt1 deacetylation and what the effects on ALF are.METHODS Mice were administrated lipopolysaccharide(LPS)/D-gal and exposed to hypoxic conditions as animal model,and resveratrol was used as an activator of Sirt1.The cellular model was established with L02 cells stimulated by LPS.N-acetyl-Lcysteine was used to remove ROS,and the expression of Sirt1 was inhibited by nicotinamide.Western blotting was used to detect Sirt1 and HIF-1αactivity and related protein expression.The possible signaling pathways involved were analyzed by immunofluorescent staining,co-immunoprecipitation,dihydroethidium staining,and Western blotting.RESULTS Compared with mice stimulated with LPS alone,the expression of Sirt1 decreased,the level of HIF-1αacetylation increased in hypoxic mice,and the levels of carbonic anhydrase 9 and Bcl-2-adenovirus E1B interacting protein 3 increased significantly,which was regulated by HIF-1α,indicating an increase of HIF-1αactivity.Under hypoxia,the down-regulation of Sirt1 activated and acetylated HIF-1αin L02 cells.The inhibition of Sirt1 significantly aggravated this effect and the massive production of ROS.The regulation of ROS was partly through peroxisome proliferatoractivated receptor alpha or AMP-activated protein kinase.Resveratrol,a Sirt1 activator,effectively relieved ALF aggravated by hypoxia,the production of ROS,and cell apoptosis.It also induced the deacetylation of HIF-1αand inhibited the activity of HIF-1α.CONCLUSION Sirt1 may have a protective effect on ALF by inducing HIF-1α deacetylation to reduce ROS.展开更多
BACKGROUND Ischemia-reperfusion injury(IRI) is a major risk associated with liver surgery and transplantation,and its pathological mechanism is complex.Interleukin-1 receptor antagonist(IL-1ra) can protect the liver f...BACKGROUND Ischemia-reperfusion injury(IRI) is a major risk associated with liver surgery and transplantation,and its pathological mechanism is complex.Interleukin-1 receptor antagonist(IL-1ra) can protect the liver from IRI.However,the regulatory mechanism of IL-1ra expression is still unclear.AIM To identify the mechanism that could protect the liver in the early stage of IRI.METHODS To screen the key genes in hepatic IRI,we performed RNA sequencing and gene enrichment analysis on liver tissue from mice with hepatic IRI.Subsequently,we verified the expression and effect of IL-1ra in hepatic IRI.We also used promoter mutagenesis and chromatin immunoprecipitation assay to search for the transcriptional regulatory sites of hypoxia-inducible factor(HIF)-1α.Finally,to explore the protective mechanism of ischemic preconditioning(IP),we examined the expression of HIF-1α and IL-1ra after IP.RESULTS We identified IL-1ra as a key regulator in hepatic IRI.The expression of IL-1ra was significantly upregulated after hepatic IRI both in vivo and in vitro.Furthermore,we found that HIF-1αregulated Il-1ra transcription in response to hypoxia.Increased HIF-1α accumulation promoted IL-1ra expression,whereas inhibition of HIF-1α exhibited the opposite effect.We also confirmed a predominant role for hypoxia response element in the regulation of Il1ra transcription by HIF-1αactivation.Of note,we demonstrated that IP protects against hepatic IRI by inducing IL-1ra expression,which is mediated through HIF-1α.CONCLUSION We demonstrated that ischemia or hypoxia leads to increased expression of IL-1ra through HIF-1α.Importantly,IP protects the liver from IRI via the HIF-1α–IL-1ra pathway.展开更多
Objective To investigate the expression of hypoxia inducible factor 1 alpha (HIF 1α) and inducible nitric oxide synthase (iNOS) genes in rats’ pulmonary arteries in different phases of hypoxia induced pulmonary ...Objective To investigate the expression of hypoxia inducible factor 1 alpha (HIF 1α) and inducible nitric oxide synthase (iNOS) genes in rats’ pulmonary arteries in different phases of hypoxia induced pulmonary hypertension development Methods Models of chronic hypoxic pulmonary hypertension rat were duplicated by intermittent hypoxia Mean pulmonary arterial pressure (mPAP) was measured by right heart catheterization HIF 1α and iNOS messenger ribonucleic acid (mRNA) were detected by in situ hybridization HIF 1α and iNOS protein were measured by immunohistochemical analysis Results Expression of HIF 1α protein was upregulated in pulmonary arterial tunica intimae of all hypoxic rats In pulmonary arterial tunica media, the level of HIF 1α protein was markedly upregulated at days 3 and 7 of hypoxia ( P 【0 01), then tended to restore at 14 days and 21 days HIF 1α mRNA levels in pulmonary arteries of rats began to increase significantly at day 14 of hypoxia ( P 【0 01) Expression of iNOS mRNA and protein in pulmonary arteries of rats were upregulated by hypoxia for 3 days ( P 【0 01), then reached its peak and maitained the same level while the extension of hypoxia Linear correlation analysis showed that iNOS protein was associated with both mean pulmonary arterial pressure ( r =0 74, P 【0 01) and hypoxic pulmonary vascular remodeling ( r =0 78, P 【0 01), whereas the inverse was associated with HIF 1α protein ( r =-0 52, P 【0 01) Conclusions HIF 1α and iNOS are both involved in the pathogenesis of hypoxia induced pulmonary hypertension in rat HIF 1α protein may upregulate the expression of iNOS gene by transcriptional activation; in addition, iNOS protein may inhibit the expression of HIF 1α protein展开更多
Background Transcription factors hypoxia inducible factor 1α (HIF 1α) and endothelial PAS domain protein 1 (EPAS1) promote the transcription of vascular endothelial growth factor (VEGF). VEGF enhances angiogen...Background Transcription factors hypoxia inducible factor 1α (HIF 1α) and endothelial PAS domain protein 1 (EPAS1) promote the transcription of vascular endothelial growth factor (VEGF). VEGF enhances angiogenesis and vascular permeability of tumours, which promotes tumour growth and facilitates entry of cancer cells into blood circulation and metastasizing. This study examined whether HIF 1α and EPAS1 stimulated angiogenesis through activation of VEGF in human pancreatic carcinoma. Methods Specimens from pancreatic carcinoma and healthy parts of same pancreas were taken from 60 patients. Real time quantitative reverse transcription polymerase chain reaction estimated expression of HIF 1α, EPAS1, and VEGF mRNAs. Western blotting and immunohistochemical, streptavidin peroxidase method assessed expression of HIF 1α, EPAS1, and VEGF proteins. Microvessel density (MVD) was assessed. Results Highly significant increases in expression of EPAS1, VEGF, and MVD were found in pancreatic carcinoma tissue but not in normal pancreatic tissue: VEGF at mRNA and protein levels (t=17.32, P=-0.0001; t=98.41, P=0.0001); EPAS1 protein level (t=22.51, P=0.0001). Expression of HIF la was similar in pancreatic carcinoma and normal pancreatic tissues at both mRNA and protein levels. Significant correlations were observed between EPAS1 and VEGF (r=0.736, P=0.0041), between VEGF and MVD (r=0.858, P=0.0001), and between EPAS1 and MVD (r=0.641, P=0.0003). No significant correlations were observed between HIF la and VEGF, or between HIF 1α and MVD. MVD and expression of EPAS1 and VEGF were significantly related with TNM staging, so was EPASI and VEGF with size of tumour. Conclusions EPAS1 and VEGF, but not HIFla, are overexpressed in pancreatic carcinoma. The expression of EPAS1 is correlated with that of VEGF and MVD. EPAS1 may be involved in the angiogenesis of pancreatic carcinoma by upregulating the expression of VEGE Targeting EPAS1 may be a new method of antiangiogenic tumour therapy for pancreatic carcinoma.展开更多
Cells are endowed with a defensive mechanism against hypoxia, namely hypoxia-inducible factor (HIF) andhypoxia-responsive element (HRE). Under hypoxic conditions, activation of HIF leads to expression of a variety...Cells are endowed with a defensive mechanism against hypoxia, namely hypoxia-inducible factor (HIF) andhypoxia-responsive element (HRE). Under hypoxic conditions, activation of HIF leads to expression of a variety of adaptive genes with HRE in a coordinated manner. The amount of HIF is regulated principally by the rate of degradation through post-translational modification by prolyl hydroxylases. Experimental studies utilizing HIF stimulating agents have been effective in a variety of kidney disease models, demonstrating that the HIF-HRE pathway is a promising target of future therapeutic approaches.展开更多
Background Growing evidence from population and clinic based studies showed that obstructive sleep apnea (OSA) and its characterizing chronic intermittent hypoxia (IH) were independently associated with the develo...Background Growing evidence from population and clinic based studies showed that obstructive sleep apnea (OSA) and its characterizing chronic intermittent hypoxia (IH) were independently associated with the development of type 2 diabetes mellitus.However,the pathogenesis by which OSA induces glucose metabolic disorders is not clear.We determined changes in pancreatic β cell mass and the mammalian target of rapamycin (mTOR)/hypoxia inducible factor 1 (HIF-1)/ vascular endothelial growth factor A (VEGF-A) pathway following IH exposure.Methods A controlled gas delivery system regulated the flow of nitrogen and oxygen into a customized cage housing mice during the experiment.Twenty-four male wild C57BL/6J mice were either exposed to IH (n=12) or intermittent air as a control (n=12) for 56 days.Mice were anaesthetized and sacrificed after exposure,pancreas samples were dissected for immunofluorescent staining.Insulin and DAPI staining labelled islet β cells.Insulin positive area and β cell number per islet were measured.P-S6,HIF-1α and VEGF-A staining were performed to detect the activation of mTOR/HIF-1NEGF-A pathway.Results After eight weeks of IH exposure,insulin positive area increased by an average of 18.5% (P 〈0.05).The β cell number per islet increased (92 vs.55,respectively for IH and the control groups,P 〈0.05) with no change in the size of individual β cells.Islet expression of HIF-1α and VEGF-A were higher in IH group than control group,and percentage of p-S6 positive β cell also increased after IH exposure (16.8% vs.4.6% respectively for IH and the control groups,P 〈0.05).Conclusion The number of pancreatic β cells increased as did the activity of the mTOR/HIF-1NEGF-A pathway after exposure to IH.展开更多
Acute myocardial ischaemia is a common acute .disease and a common cause of sudden death.However, it is difficult to diagnose in patients who died within 6 hours after the onset of myocardial ischaemia. The occurrence...Acute myocardial ischaemia is a common acute .disease and a common cause of sudden death.However, it is difficult to diagnose in patients who died within 6 hours after the onset of myocardial ischaemia. The occurrence of sudden cardiac death often has pathological basis of primary heart diseases, which may lead to a series of changes in metabolism and gene expression.1 Recent research found that hypoxia inducible factor 1 alpha (HIF-1α) is a sensitive marker of hypoxia; its gene expression is upregulated within several minutes after acute myocardial ischaemia, followed by the upregulation of its protein and its expression will remain high if the inducement continues. Its expression in nonhypoxic cardiac muscle is very low. This characteristic may be used to differentiate hypoxic factors from nonhypoxic factors, and help to judge the cause of death. This study explored the expression of HIF-1α in hypoxic cardiac muscle by establishing an acute myocardial ischaemia model in mice, and observed its dynamic changes to provide reference for analysing causes of death within 48 hours after death.展开更多
Cobalt is one of the main components of metal hip prostheses and cobalt nanoparticles(CoNPs)produced from wear cause inflammation,bone lyses and cytotoxicity at high concentrations.Cobalt ions mimic hypoxia in the pre...Cobalt is one of the main components of metal hip prostheses and cobalt nanoparticles(CoNPs)produced from wear cause inflammation,bone lyses and cytotoxicity at high concentrations.Cobalt ions mimic hypoxia in the presence of normal oxygen levels,and activate hypoxic signalling by stabilising hypoxia inducible transcription factor 1α(HIF1α).This study aimed to assess in vitro the functional role of HIF1αin CoNP induced cellular cytotoxicity.HIF1α,lysosomal pH,tumour necrosis factorαand interleukin 1βexpression were analysed in THP-1 macrophages treated with CoNP(0,10 and 100μg/mL).HIF1αknock out assays were performed using small interfering RNA to assess the role of HIF1αin CoNP-induced cytotoxicity.Increasing CoNP concentration increased lysosomal activity and acidity in THP-1 macrophages.Higher doses of CoNP significantly reduced cell viability,stimulated caspase 3 activity and apoptosis.Reducing HIF1αactivity increased the pro-inflammatory activity of tumour necrosis factorαand interleukin 1β,but had no significant impact on cellular cytotoxicity.This suggests that whilst CoNP promotes cytotoxicity and cellular inflammation,the apoptotic mechanism is not dependent on HIF1α.展开更多
Objective To understand the effects of clock gene BMAL1 and HIF-1α(Hypoxia inducible factor-1α)on proliferation,migration and sensitivity to radiotherapy of nasopharyngeal carcinoma cells HONE1.At the same time,whet...Objective To understand the effects of clock gene BMAL1 and HIF-1α(Hypoxia inducible factor-1α)on proliferation,migration and sensitivity to radiotherapy of nasopharyngeal carcinoma cells HONE1.At the same time,whether the biological clock gene BMAL1 can affect the expression of HIF-1αprotein was investigated.It will lay the foundation for further study on the correlation between clock gene BMAL1 and HIF pathway.Methods BMAL1 gene overexpression and interference lentivirus and HIF-1αgene interference lentivirus were constructed respectively,and were transfected into nasopharyngeal carcinoma cells HONE1.Western blot was used to verify the establishment of overexpressed and knockdown BMAL1 cell lines and HIF-1αgene knockdown cell line,and to investigate the expression of HIF-1αprotein in overexpressed and knockdown BMAL1 cell lines.CCK-8 cell proliferation test and scratch test were used to analyze the proliferation and migration ability of cells.Cell apoptosis after radiotherapy was analyzed by flow cytometry.The effects of BMAL1 and HIF-1αon the sensitivity of HONE1 radiotherapy in nasopharyngeal carcinoma cells after X-ray irradiation at different doses(0Gy,2Gy,4Gy,6Gy)were detected by clone formation assay.Results The overexpression of BMAL1 gene and lentivirus interference were constructed to effectively up regulate and down regulate the expression of BMAL1 protein in nasopharyngeal carcinoma cells HONE1.Meanwhile,HIF-1αgene interference lentivirus was constructed to effectively down-regulate the expression of HIF-1αprotein in nasopharyngeal carcinoma cell line HONE1,and successfully screen out stable nasopharyngeal carcinoma cell lines.Western blot results showed that overexpression of BMAL1 gene could inhibit the expression of HIF-1αprotein in HONE1 of nasopharyngeal carcinoma cells,while knockdown of BMAL1 gene promoted the expression of HIF-1αprotein in HONE1 of nasopharyngeal carcinoma cells(P<0.05).CCK-8 cell proliferation and scratch test showed that overexpression of BMAL1 gene or knockdown of HIF-1αgene could inhibit the proliferation and migration of HONE1 cells(P<0.05).Flow cytometry results showed that after 8Gy irradiation for 72 h,the apoptosis rate of BMALl gene overexpression group was higher than that of the overexpression control group,similarly,the apoptosis rate of HIF-1αgene knockdown group was higher than that of the knockdown control group(P<0.05).After X-ray irradiation at different doses(0Gy,2Gy,4Gy,6Gy),clon-formation experiment showed that the clon-formation rate and cell survival fraction of BMALl overexpression group or HIF-1αknockdown group were lower than those of negative control group(P<0.05).Sigmaplot analysis showed that the D0,Dq and SF2 of the BMAL1 overexpression group or HIF-1αknockdown group were lower than those of the negative control group,and the radiosensitization ratios were 1.381 and 1.063,respectively.Conclusion Overexpression of BMAL1 gene can inhibit the proliferation and migration of nasopharyngeal carcinoma cell line HONE1,increase apoptosis after radiotherapy and improve radiosensitivity.Knock down HIF-1αGene can inhibit the proliferation and migration of nasopharyngeal carcinoma cell line HONE1,increase apoptosis after radiotherapy and improve radiosensitivity.In nasopharyngeal carcinoma cells HONE1,overexpression of BMAL1 gene can inhibit the expression of HIF-1αprotein while knockdown of BMAL1 gene can promote the expression of HIF-1αprotein.展开更多
Objective: To study the role of the expression of nerve growth factor inducible protein B gene (NGFI-B) in striatum in the pathogenesis of levodopa-induced dyskinesias (LID). Methods: The rat model of LID was tr...Objective: To study the role of the expression of nerve growth factor inducible protein B gene (NGFI-B) in striatum in the pathogenesis of levodopa-induced dyskinesias (LID). Methods: The rat model of LID was treated with SCH 23390(1 mg/kg ip,a dopamine D1 antagonist) and haloperidol (1 mg/kg ip,a dopanfme D2 antagonist) respectively. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the expression of NGFI-B mRNA in stiiatam and the behavior changes were observed. Resuits: After treatment with SCH23390, abnormal involuntary movement (AIM) in LID rats was decreased ( P 〈 0.05 ) and the expression of NGFI-B mRNA in striatum did not change significantly. After treatment with haloperidol, the changes of AIM in LID rats were not significant and the expression of NGFI-B mRNA was increased significantly( P 〈 0.01). Conclusion: LID is associated with over-expression of NGFI-B in striatum. Abnormal activity in the direct pathway and the basal ganglia circuit could be involved in the occurrence of LID.展开更多
Perinatal complications,such as asphyxia,can cause brain injuries that are often associated with subsequent neurological deficits,such as cerebral palsy or mental retardation.The mechanisms of perinatal brain injury a...Perinatal complications,such as asphyxia,can cause brain injuries that are often associated with subsequent neurological deficits,such as cerebral palsy or mental retardation.The mechanisms of perinatal brain injury are not fully understood,but mitochondria play a prominent role not only due to their central function in metabolism but also because many proteins with apoptosis-related functions are located in the mitochondrion.Among these proteins,apoptosis-inducing factor has already been shown to be an important factor involved in neuronal cell death upon hypoxia-ischemia,but a better understanding of the mechanisms behind these processes is required for the development of more effective treatments during the early stages of perinatal brain injury.In this review,we focus on the molecular mechanisms of hypoxic-ischemic encephalopathy,specifically on the importance of apoptosis-inducing factor.The relevance of apoptosis-inducing factor is based not only because it participates in the caspase-independent apoptotic pathway but also because it plays a crucial role in mitochondrial energetic functionality,especially with regard to the maintenance of electron transport during oxidative phosphorylation and in oxidative stress,acting as a free radical scavenger.We also discuss all the different apoptosis-inducing factor isoforms discovered,focusing especially on apoptosis-inducing factor 2,which is only expressed in the brain and the functions of which are starting now to be clarified.Finally,we summarized the interaction of apoptosis-inducing factor with several proteins that are crucial for both apoptosis-inducing factor functions(prosurvival and pro-apoptotic)and that are highly important in order to develop promising therapeutic targets for improving outcomes after perinatal brain injury.展开更多
BACKGROUND: Therapeutic angiogenesis has opened up new pathway for the treatment of ischemic cerebrovascular disease in recent years. The exploration of the effect of vascular endothelial growth factor (VEGF) on in...BACKGROUND: Therapeutic angiogenesis has opened up new pathway for the treatment of ischemic cerebrovascular disease in recent years. The exploration of the effect of vascular endothelial growth factor (VEGF) on inducing angiogenesis following ischemia/reperfusion injury can provide better help for the long-term treatment of cerebrovascular disease in clinic. OBJECTIVE: To observe the effect of VEGF on inducing angiogenesis following focal cerebral ischemia /reperfusion injury in rabbits through the angiogenesis of microvessels reflected by the expression of the factors of vascular pseudohemophilia. DESIGN: A randomized controlled animal tria SETTNG: Department of Medical Imaging, Second Hospital of Hebei Medical University MATERIALS: Sixty-five healthy male New Zealand rabbits of clean degree, weighing (2.6±0.2) kg, aged 4.5-5 months, were used. The polyclonal antibody against vascular pseudohemophilia (Beijing Zhongshan Company), recombinant VEGF165 (Peprotech Company, USA), biotinylated second antibody and ABC compound (Wuhan Boster Company) were applied. METHODS: The experiments were carried out in the Laboratory of Neuromolecular Imaging and Neuropathy, Second Hospital of Hebei Medical University from May to August in 2005. (1) The rabbits were randomly divided into three groups: sham-operated group (n=15), control group (n=25) and VEGF-treated group (n=-25). In the control group and VEGF-treated group, models were established by middle cerebral artery occlusion (MCAO) induced focal cerebral ischemia/reperfusion. In the VEGF-treated group, VEGF165 (2.5 mg/L) was stereotactically injected into the surrounding regions of the infarcted sites immediately after the 2-hour ischemia/reperfusion; Saline of the same dosage was injected in the control group. But the rabbits in the sham-operated group were only drilled but not administrated. (2) The experimental indexes were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment respectively, 3 rabbits in the sham-operated group and 5 in the control group and VEGF-treated group were observed at each time point. The brain tissues in the surrounding regions of the infarcted sites were collected. The positive expressions of the factors of vascular pseudohemophilia in vascular endothelial cells were analyzed with immunohistochemical method. The microvessels in unit statistical field were counted with the imaging analytical software. MAIN OUTCOME MEASURES: The changes of microvascular density in the brain tissue and the positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of the infarcted sites were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment. RESULTS: All the 65 New Zealand rabbits were involved in the analysis of results without deletion. Changes of the number of microvessels at different time points in each group: There were no obvious changes at different time points in the sham-operated group. The numbers of microvessels at 7 and 14 days were obviously more in the control group than in the sham-operated group [(6.0±1.1), (9.0±0.9) microvessels; (3.0±1.1), (3.0±1.1) microvessels; P〈 0.05-0.01], and those at 3, 7, 14 and 28 days were obviously more in the VEGF-treated group than in the control group [(8.3±2.0), (13.4±1.4), (15.5±2.3), (6.8± 1.0) microvessels; (3.4±0.6), (6.0±1.1), (9.0±0.9), (3.2±0.8) microvessels; P 〈 0.01]. (2) Positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of infarcted sites: There were no obvious changes at different time points in the sham-operated group. In the control group, the changing law of the expressions was the same as that for the number of microvessels that the expression began to mildly increase at 7 days, reached the peak value at 14 days, and began to reduce at 28 days. In the VEGF-treated group, the expression was obviously increased at 3 days, also reached the peak value at 14 days, and reduced to the normal level at 70 days, but the expressions were obviously stronger than those in the control group at the same time points. CONCLUSION: Angiogenesis can be obviously induced in rabbits after the focal cerebral ischemia/reperfusion injury is treated with VEGF for 18 days.展开更多
The defining neuropathological feature of Parkinson's disease (PD) is the loss of nigrostriatal dopaminergic (DA) projections. This results in striatal dopamine levels and a biochemical reduction of movement diso...The defining neuropathological feature of Parkinson's disease (PD) is the loss of nigrostriatal dopaminergic (DA) projections. This results in striatal dopamine levels and a biochemical reduction of movement disorders, such as a tremor at rest, rigidity of the limbs, bradykinesia, and postural instability (Kim et al., 2011; Kim et al., 2012; Burke and O'Malley, 2013; Leem et al., 2014; Namet al., 2014).展开更多
Introduction Thrombosis is the formation of a blood clot in a blood vessel. When thrombosis happens in the brain,it would cause stroke; when happens in the heart,it would cause heart attack. If a thrombus breaks and t...Introduction Thrombosis is the formation of a blood clot in a blood vessel. When thrombosis happens in the brain,it would cause stroke; when happens in the heart,it would cause heart attack. If a thrombus breaks and travels to the lung,it would展开更多
BACKGROUND: Receptors for tumor necrosis factor related apoptosis inducing ligand (TRAIL) include death receptor 4, death receptor 5, decoy receptor 1, and decoy receptor 2. Activation of death receptor 4 and 5 sel...BACKGROUND: Receptors for tumor necrosis factor related apoptosis inducing ligand (TRAIL) include death receptor 4, death receptor 5, decoy receptor 1, and decoy receptor 2. Activation of death receptor 4 and 5 selectively kills tumor cells. OBJECTIVE: To detect TRAIL receptor expression in glioblastoma by immunohistochemistry and RT-PCR, and to compare this expression to that in normal brain tissue. DESIGN: Observational analysis. SETTING: Department of Pathology, the First Affiliated Hospital of Zhengzhou University; Henan Tumor Pathology Key Laboratory. PARTICIPANTS: Twenty-five patients (17 males and 8 females) who received glioblastoma resection were selected from the Fifth Affiliated Hospital of Zhengzhou University, between September 2003 to June 2004. All glioblastoma samples were diagnosed pathologically. Twenty patients (12 males and 8 females) with craniocerebral injury who received normal brain tissue resection were selected in the same time period. There were no significant differences in sex and age between glioblastoma patients or between craniocerebral injury patients (P 〉 0.05). All patients and appropriate relatives provided informed consent, and this study was approved by the local research ethics committee. METHODS: Polyclonal antibody against TRAIL receptors and an immunohistochemical kit (batch number: 200502) were purchased from Boster Company, Wuhan. Immunohistochemistry: Expression of death receptor 4, death receptor 5, decoy receptor l, and decoy receptor 2 were observed in both glioblastoma and normal brain tissue. The experiment was performed according to the kit instructions, and positive staining was brown-yellow. Assessment: There were no positive signals (-); weakly positive signals, positive cells 〈 25% (+); weakly positive signals, positive cells 25%-50% (++); strongly positive signals, positive cells 50%-75% (+++); strongly positive signals, positive cells 〉 75% (++++). Evaluation: Expression levels of TRAIL receptors were estimated in both normal brain tissue and glioblastoma. Expression of decoy receptor 1 and decoy receptor 2 mRNA in glioblastoma were detected by reverse transcription polymerase chain reaction, and expression of decoy receptor in glioblastoma was estimated. MAIN OUTCOME MEASURES: Comparison of death receptor and decoy receptor protein expression between glioblastoma and normal brain tissue; decoy receptor mRNA expression in glioblastoma. RESULTS: Death receptor protein expression was strongly positive (+++) in glioblastoma, while it was weakly positive (+, ++) in normal brain tissue. Therefore, expression rate of death receptor protein in the glioblastoma was significantly higher than that in the normal brain tissue (.~ 2 = 18.48, 23.03, P 〈 0.01). Decoy receptor protein expression in the glioblastoma was significantly lower than that in the normal brain tissue ( x2 = 6.65, 18.76, P 〈 0.01). The level of decoy receptor mRNA expression in glioblastoma was significantly higher than those of protein expression ( x 2 = 9.82, 10.09, P〈 0.01). CONCLUSION: High expression of death receptor and low expression of decoy receptor are frequently observed in glioblastoma, suggesting that TRAIL receptor genes show an anti-tumor and expressive response during the initiation and development of the tumor. There are significant differences in decoy receptor expression between normal brain tissue and glioblastoma, suggesting that the restricted expression of decoy receptor in glioblastoma is regulated at the post-transcriptional level.展开更多
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.
文摘The role of the hypoxia-inducible factor(HIF)subunits 1α and 2α in response to hypoxia is well established in lungepithelial cells,whereas little is known about HIF-3α with respect to transcriptional and translational regulation by hy-poxia.HIF-3α and HIF-1α are two similar but distinct basic helix-loop-helix-PAS proteins,which have been postulatedto activate hypoxia responsive genes in response to hypoxia.Here,we used quantitative real time RT-PCR and immu-noblotting to determine the activation of HIF-3α vs.HIF-1α by hypoxia.HIF-3α was strongly induced by hypoxia(1%O_2)both at the level of protein and mRNA due to an increase in protein stability and transcriptional activation,whereasHIF-1α protein and mRNA levels enhanced transiently and then decreased because of a reduction in its mRNA stabilityin A549 cells,as measured on mRNA and protein levels.Interestingly,HIF-3α and HIF-1α exhibited strikingly similarresponses to a variety of activating or inhibitory pharmacological agents.These results demonstrate that HIF-3α is ex-pressed abundantly in lung epithelial cells,and that the transcriptional induction of HIF-3α plays an important role in theresponse to hypoxia in vitro.Our findings suggest that HIF-3α,as a member of the HIF system,is complementary ratherthan redundant to HIF-1α induction in protection against hypoxic damage in alveolar epithelial cells.
文摘DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-butylphthalide action by various means.We used hydrogen peroxide to induce injury to PC12cells and RAW264.7 cells to mimic neuronal oxidative stress injury in stroke in vitro and examined the effects of DI-3-n-butylphthalide.We found that DI-3-nbutylphthalide pretreatment markedly inhibited the reduction in viability and reactive oxygen species production in PC12 cells caused by hydrogen peroxide and inhibited cell apoptosis.Furthermore,DI-3-n-butylphthalide pretreatment inhibited the expression of the pro-apoptotic genes Bax and Bnip3.DI-3-nbutylphthalide also promoted ubiquitination and degradation of hypoxia inducible factor 1α,the key transcription factor that regulates Bax and Bnip3 genes.These findings suggest that DI-3-n-butylphthalide exhibits a neuroprotective effect on stroke by promoting hypoxia inducible factor-1α ubiquitination and degradation and inhibiting cell apoptosis.
基金Supported by Research Project for Jiangxi Educational Department,No.180086.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a malignant tumor that occurs in the liver.Its onset is latent,and it shows high heterogeneity and can readily experience intrahepatic metastasis or systemic metastasis,which seriously affects patients’quality of life.Numerous studies have shown that hypoxia inducible factor1α(HIF-1α)plays a significant role in the occurrence and development of tumors,as it promotes the formation of intratumoral vessels and plays a key role in their metastasis and invasion.Some studies have reported that caspase-3,which is induced by various factors,is involved in the apoptosis of tumor cells.AIM To investigate the expression of caspase-3 and HIF-1αand their relationship to the prognosis of patients with primary HCC complicated by pathological changes of hemorrhage and necrosis.METHODS A total of 88 patients with HCC complicated by pathological changes of hemorrhage and necrosis who were treated at our hospital from January 2017 to December 2019 were selected.The expression of caspase-3 and HIF-1αin HCC and paracancerous tissues from these patients was assessed.RESULTS The positive expression rate of caspase-3 in HCC tissues was 27.27%,which was significantly lower than that in the paracancerous tissues(P<0.05),while the positive expression rate of HIF-1αwas 72.73%,which was significantly higher than that in the paracancerous tissues(P<0.05).The positive expression rates for caspase-3 in tumor node metastasis(TNM)stage III and lymph node metastasis tissues were 2.78%and 2.50%,respectively,which were significantly lower than those in TNM stage I-II and non-lymph node metastasis tissues(P<0.05).The positive expression rates of HIF-1αin TNM stage III,lymph node metastasis,and portal vein tumor thrombus tissues were 86.11%,87.50%,and 88.00%,respectively,and these values were significantly higher than those in TNM stage I-II,non-lymph node metastasis,and portal vein tumor thrombus tissues(P<0.05).The expression of caspase-3 and HIF-1αin HCC tissues were negatively correlated(rs=−0.426,P<0.05).The median overall survival time of HCC patients was 18.90 mo(95%CI:17.20–19.91).The results of the Cox proportional risk regression model analysis showed that TNM stage,portal vein tumor thrombus,lymph node metastasis,caspase-3 expression,and HIF-1αexpression were the factors influencing patient prognosis(P<0.05).CONCLUSION The expression of caspase-3 decreases and HIF-1αincreases in HCC tissues complicated by pathological changes of hemorrhage and necrosis,and these are related to clinicopathological features and prognosis.
基金supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo,Conselho Nacional de Desenvolvimento Científico e Tecnologico (NO.2009/10771-9)Coordenacao de Aperfeicoamento de Pessoal de Nível Superior (NO.301052/2009-3),Brazil
文摘Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α present antileishmanial properties.Methods:The leishmanicidal effect of drugs was evaluated in mouse macrophages and Balb/c mouse model for cutaneous leishmaniosis.Results:Resveratrol and CdCl_2 reduced the parasite load [IC50,(27.3±2.25) μM and(24.8±0.95) μM,respectively].The IC50 value of echinomycin was(22.7±7.36) nM and mimosine did not alter the parasite load in primary macrophages.The macrophage viability IC50 values for resveratrol,echinomycin and CdCl_2 and mimosine were >40 μM,>100 nM,> 200 μM and>2 000 μM,respectively.In vivo no differences between cutaneous lesions from control,resveratrol-and echinomycin-treated Balb/c mice were detected.Conclusions:Resveratrol,echinomycin and CdCl_2 reduce parasite survival in vitro.The HIF-1α targeting pharmacological drugs require further study to more fully determine their anti-Leishmania potential and their role in therapeutic strategies.
基金Supported by National Natural Science Foundation of China,No. 82070609
文摘BACKGROUND The occurrence and development of acute liver failure(ALF)is closely related to a series of inflammatory reactions,such as the production of reactive oxygen species(ROS).Hypoxia inducible factor 1α(HIF-1α)is a key factor that regulates oxygen homeostasis and redox,and the stability of HIF-1αis related to the ROS level regulated by Sirtuin(Sirt)family.The activation of Sirt1 will lead to a powerful antioxidant defense system and therapeutic effects in liver disease.However,little is known about the relationship between HIF-1αand Sirt1 in the process of ALF and the molecular mechanism.AIM To investigate whether HIF-1αmay be a target of Sirt1 deacetylation and what the effects on ALF are.METHODS Mice were administrated lipopolysaccharide(LPS)/D-gal and exposed to hypoxic conditions as animal model,and resveratrol was used as an activator of Sirt1.The cellular model was established with L02 cells stimulated by LPS.N-acetyl-Lcysteine was used to remove ROS,and the expression of Sirt1 was inhibited by nicotinamide.Western blotting was used to detect Sirt1 and HIF-1αactivity and related protein expression.The possible signaling pathways involved were analyzed by immunofluorescent staining,co-immunoprecipitation,dihydroethidium staining,and Western blotting.RESULTS Compared with mice stimulated with LPS alone,the expression of Sirt1 decreased,the level of HIF-1αacetylation increased in hypoxic mice,and the levels of carbonic anhydrase 9 and Bcl-2-adenovirus E1B interacting protein 3 increased significantly,which was regulated by HIF-1α,indicating an increase of HIF-1αactivity.Under hypoxia,the down-regulation of Sirt1 activated and acetylated HIF-1αin L02 cells.The inhibition of Sirt1 significantly aggravated this effect and the massive production of ROS.The regulation of ROS was partly through peroxisome proliferatoractivated receptor alpha or AMP-activated protein kinase.Resveratrol,a Sirt1 activator,effectively relieved ALF aggravated by hypoxia,the production of ROS,and cell apoptosis.It also induced the deacetylation of HIF-1αand inhibited the activity of HIF-1α.CONCLUSION Sirt1 may have a protective effect on ALF by inducing HIF-1α deacetylation to reduce ROS.
基金the National Natural Science Foundation of China,No.81670600.
文摘BACKGROUND Ischemia-reperfusion injury(IRI) is a major risk associated with liver surgery and transplantation,and its pathological mechanism is complex.Interleukin-1 receptor antagonist(IL-1ra) can protect the liver from IRI.However,the regulatory mechanism of IL-1ra expression is still unclear.AIM To identify the mechanism that could protect the liver in the early stage of IRI.METHODS To screen the key genes in hepatic IRI,we performed RNA sequencing and gene enrichment analysis on liver tissue from mice with hepatic IRI.Subsequently,we verified the expression and effect of IL-1ra in hepatic IRI.We also used promoter mutagenesis and chromatin immunoprecipitation assay to search for the transcriptional regulatory sites of hypoxia-inducible factor(HIF)-1α.Finally,to explore the protective mechanism of ischemic preconditioning(IP),we examined the expression of HIF-1α and IL-1ra after IP.RESULTS We identified IL-1ra as a key regulator in hepatic IRI.The expression of IL-1ra was significantly upregulated after hepatic IRI both in vivo and in vitro.Furthermore,we found that HIF-1αregulated Il-1ra transcription in response to hypoxia.Increased HIF-1α accumulation promoted IL-1ra expression,whereas inhibition of HIF-1α exhibited the opposite effect.We also confirmed a predominant role for hypoxia response element in the regulation of Il1ra transcription by HIF-1αactivation.Of note,we demonstrated that IP protects against hepatic IRI by inducing IL-1ra expression,which is mediated through HIF-1α.CONCLUSION We demonstrated that ischemia or hypoxia leads to increased expression of IL-1ra through HIF-1α.Importantly,IP protects the liver from IRI via the HIF-1α–IL-1ra pathway.
文摘Objective To investigate the expression of hypoxia inducible factor 1 alpha (HIF 1α) and inducible nitric oxide synthase (iNOS) genes in rats’ pulmonary arteries in different phases of hypoxia induced pulmonary hypertension development Methods Models of chronic hypoxic pulmonary hypertension rat were duplicated by intermittent hypoxia Mean pulmonary arterial pressure (mPAP) was measured by right heart catheterization HIF 1α and iNOS messenger ribonucleic acid (mRNA) were detected by in situ hybridization HIF 1α and iNOS protein were measured by immunohistochemical analysis Results Expression of HIF 1α protein was upregulated in pulmonary arterial tunica intimae of all hypoxic rats In pulmonary arterial tunica media, the level of HIF 1α protein was markedly upregulated at days 3 and 7 of hypoxia ( P 【0 01), then tended to restore at 14 days and 21 days HIF 1α mRNA levels in pulmonary arteries of rats began to increase significantly at day 14 of hypoxia ( P 【0 01) Expression of iNOS mRNA and protein in pulmonary arteries of rats were upregulated by hypoxia for 3 days ( P 【0 01), then reached its peak and maitained the same level while the extension of hypoxia Linear correlation analysis showed that iNOS protein was associated with both mean pulmonary arterial pressure ( r =0 74, P 【0 01) and hypoxic pulmonary vascular remodeling ( r =0 78, P 【0 01), whereas the inverse was associated with HIF 1α protein ( r =-0 52, P 【0 01) Conclusions HIF 1α and iNOS are both involved in the pathogenesis of hypoxia induced pulmonary hypertension in rat HIF 1α protein may upregulate the expression of iNOS gene by transcriptional activation; in addition, iNOS protein may inhibit the expression of HIF 1α protein
文摘Background Transcription factors hypoxia inducible factor 1α (HIF 1α) and endothelial PAS domain protein 1 (EPAS1) promote the transcription of vascular endothelial growth factor (VEGF). VEGF enhances angiogenesis and vascular permeability of tumours, which promotes tumour growth and facilitates entry of cancer cells into blood circulation and metastasizing. This study examined whether HIF 1α and EPAS1 stimulated angiogenesis through activation of VEGF in human pancreatic carcinoma. Methods Specimens from pancreatic carcinoma and healthy parts of same pancreas were taken from 60 patients. Real time quantitative reverse transcription polymerase chain reaction estimated expression of HIF 1α, EPAS1, and VEGF mRNAs. Western blotting and immunohistochemical, streptavidin peroxidase method assessed expression of HIF 1α, EPAS1, and VEGF proteins. Microvessel density (MVD) was assessed. Results Highly significant increases in expression of EPAS1, VEGF, and MVD were found in pancreatic carcinoma tissue but not in normal pancreatic tissue: VEGF at mRNA and protein levels (t=17.32, P=-0.0001; t=98.41, P=0.0001); EPAS1 protein level (t=22.51, P=0.0001). Expression of HIF la was similar in pancreatic carcinoma and normal pancreatic tissues at both mRNA and protein levels. Significant correlations were observed between EPAS1 and VEGF (r=0.736, P=0.0041), between VEGF and MVD (r=0.858, P=0.0001), and between EPAS1 and MVD (r=0.641, P=0.0003). No significant correlations were observed between HIF la and VEGF, or between HIF 1α and MVD. MVD and expression of EPAS1 and VEGF were significantly related with TNM staging, so was EPASI and VEGF with size of tumour. Conclusions EPAS1 and VEGF, but not HIFla, are overexpressed in pancreatic carcinoma. The expression of EPAS1 is correlated with that of VEGF and MVD. EPAS1 may be involved in the angiogenesis of pancreatic carcinoma by upregulating the expression of VEGE Targeting EPAS1 may be a new method of antiangiogenic tumour therapy for pancreatic carcinoma.
文摘Cells are endowed with a defensive mechanism against hypoxia, namely hypoxia-inducible factor (HIF) andhypoxia-responsive element (HRE). Under hypoxic conditions, activation of HIF leads to expression of a variety of adaptive genes with HRE in a coordinated manner. The amount of HIF is regulated principally by the rate of degradation through post-translational modification by prolyl hydroxylases. Experimental studies utilizing HIF stimulating agents have been effective in a variety of kidney disease models, demonstrating that the HIF-HRE pathway is a promising target of future therapeutic approaches.
文摘Background Growing evidence from population and clinic based studies showed that obstructive sleep apnea (OSA) and its characterizing chronic intermittent hypoxia (IH) were independently associated with the development of type 2 diabetes mellitus.However,the pathogenesis by which OSA induces glucose metabolic disorders is not clear.We determined changes in pancreatic β cell mass and the mammalian target of rapamycin (mTOR)/hypoxia inducible factor 1 (HIF-1)/ vascular endothelial growth factor A (VEGF-A) pathway following IH exposure.Methods A controlled gas delivery system regulated the flow of nitrogen and oxygen into a customized cage housing mice during the experiment.Twenty-four male wild C57BL/6J mice were either exposed to IH (n=12) or intermittent air as a control (n=12) for 56 days.Mice were anaesthetized and sacrificed after exposure,pancreas samples were dissected for immunofluorescent staining.Insulin and DAPI staining labelled islet β cells.Insulin positive area and β cell number per islet were measured.P-S6,HIF-1α and VEGF-A staining were performed to detect the activation of mTOR/HIF-1NEGF-A pathway.Results After eight weeks of IH exposure,insulin positive area increased by an average of 18.5% (P 〈0.05).The β cell number per islet increased (92 vs.55,respectively for IH and the control groups,P 〈0.05) with no change in the size of individual β cells.Islet expression of HIF-1α and VEGF-A were higher in IH group than control group,and percentage of p-S6 positive β cell also increased after IH exposure (16.8% vs.4.6% respectively for IH and the control groups,P 〈0.05).Conclusion The number of pancreatic β cells increased as did the activity of the mTOR/HIF-1NEGF-A pathway after exposure to IH.
基金National Natural Science Foundation of China(No.30500610)
文摘Acute myocardial ischaemia is a common acute .disease and a common cause of sudden death.However, it is difficult to diagnose in patients who died within 6 hours after the onset of myocardial ischaemia. The occurrence of sudden cardiac death often has pathological basis of primary heart diseases, which may lead to a series of changes in metabolism and gene expression.1 Recent research found that hypoxia inducible factor 1 alpha (HIF-1α) is a sensitive marker of hypoxia; its gene expression is upregulated within several minutes after acute myocardial ischaemia, followed by the upregulation of its protein and its expression will remain high if the inducement continues. Its expression in nonhypoxic cardiac muscle is very low. This characteristic may be used to differentiate hypoxic factors from nonhypoxic factors, and help to judge the cause of death. This study explored the expression of HIF-1α in hypoxic cardiac muscle by establishing an acute myocardial ischaemia model in mice, and observed its dynamic changes to provide reference for analysing causes of death within 48 hours after death.
文摘Cobalt is one of the main components of metal hip prostheses and cobalt nanoparticles(CoNPs)produced from wear cause inflammation,bone lyses and cytotoxicity at high concentrations.Cobalt ions mimic hypoxia in the presence of normal oxygen levels,and activate hypoxic signalling by stabilising hypoxia inducible transcription factor 1α(HIF1α).This study aimed to assess in vitro the functional role of HIF1αin CoNP induced cellular cytotoxicity.HIF1α,lysosomal pH,tumour necrosis factorαand interleukin 1βexpression were analysed in THP-1 macrophages treated with CoNP(0,10 and 100μg/mL).HIF1αknock out assays were performed using small interfering RNA to assess the role of HIF1αin CoNP-induced cytotoxicity.Increasing CoNP concentration increased lysosomal activity and acidity in THP-1 macrophages.Higher doses of CoNP significantly reduced cell viability,stimulated caspase 3 activity and apoptosis.Reducing HIF1αactivity increased the pro-inflammatory activity of tumour necrosis factorαand interleukin 1β,but had no significant impact on cellular cytotoxicity.This suggests that whilst CoNP promotes cytotoxicity and cellular inflammation,the apoptotic mechanism is not dependent on HIF1α.
基金supported in part by grants from the National Natural Science Foundation of China under grant number 82060556,81560437the Department of Science and Technology,Guizhou Province,under grant number[2018]2755+3 种基金the Ordinary Colleges and Universities Youth Science and Technology Talent Growth Project,Guizhou Province,under grant number[2021]187The Health Commission Science and Technology Fund,Guizhou Provincial under grant number gzwkj2021-050Guizhou Medical University 2021 National Foundation Cultivation Project[20NSP041]the Hospital-level Science and Technology Project of Guizhou Cancer Hospital under grant number YJ2019-33.
文摘Objective To understand the effects of clock gene BMAL1 and HIF-1α(Hypoxia inducible factor-1α)on proliferation,migration and sensitivity to radiotherapy of nasopharyngeal carcinoma cells HONE1.At the same time,whether the biological clock gene BMAL1 can affect the expression of HIF-1αprotein was investigated.It will lay the foundation for further study on the correlation between clock gene BMAL1 and HIF pathway.Methods BMAL1 gene overexpression and interference lentivirus and HIF-1αgene interference lentivirus were constructed respectively,and were transfected into nasopharyngeal carcinoma cells HONE1.Western blot was used to verify the establishment of overexpressed and knockdown BMAL1 cell lines and HIF-1αgene knockdown cell line,and to investigate the expression of HIF-1αprotein in overexpressed and knockdown BMAL1 cell lines.CCK-8 cell proliferation test and scratch test were used to analyze the proliferation and migration ability of cells.Cell apoptosis after radiotherapy was analyzed by flow cytometry.The effects of BMAL1 and HIF-1αon the sensitivity of HONE1 radiotherapy in nasopharyngeal carcinoma cells after X-ray irradiation at different doses(0Gy,2Gy,4Gy,6Gy)were detected by clone formation assay.Results The overexpression of BMAL1 gene and lentivirus interference were constructed to effectively up regulate and down regulate the expression of BMAL1 protein in nasopharyngeal carcinoma cells HONE1.Meanwhile,HIF-1αgene interference lentivirus was constructed to effectively down-regulate the expression of HIF-1αprotein in nasopharyngeal carcinoma cell line HONE1,and successfully screen out stable nasopharyngeal carcinoma cell lines.Western blot results showed that overexpression of BMAL1 gene could inhibit the expression of HIF-1αprotein in HONE1 of nasopharyngeal carcinoma cells,while knockdown of BMAL1 gene promoted the expression of HIF-1αprotein in HONE1 of nasopharyngeal carcinoma cells(P<0.05).CCK-8 cell proliferation and scratch test showed that overexpression of BMAL1 gene or knockdown of HIF-1αgene could inhibit the proliferation and migration of HONE1 cells(P<0.05).Flow cytometry results showed that after 8Gy irradiation for 72 h,the apoptosis rate of BMALl gene overexpression group was higher than that of the overexpression control group,similarly,the apoptosis rate of HIF-1αgene knockdown group was higher than that of the knockdown control group(P<0.05).After X-ray irradiation at different doses(0Gy,2Gy,4Gy,6Gy),clon-formation experiment showed that the clon-formation rate and cell survival fraction of BMALl overexpression group or HIF-1αknockdown group were lower than those of negative control group(P<0.05).Sigmaplot analysis showed that the D0,Dq and SF2 of the BMAL1 overexpression group or HIF-1αknockdown group were lower than those of the negative control group,and the radiosensitization ratios were 1.381 and 1.063,respectively.Conclusion Overexpression of BMAL1 gene can inhibit the proliferation and migration of nasopharyngeal carcinoma cell line HONE1,increase apoptosis after radiotherapy and improve radiosensitivity.Knock down HIF-1αGene can inhibit the proliferation and migration of nasopharyngeal carcinoma cell line HONE1,increase apoptosis after radiotherapy and improve radiosensitivity.In nasopharyngeal carcinoma cells HONE1,overexpression of BMAL1 gene can inhibit the expression of HIF-1αprotein while knockdown of BMAL1 gene can promote the expression of HIF-1αprotein.
文摘Objective: To study the role of the expression of nerve growth factor inducible protein B gene (NGFI-B) in striatum in the pathogenesis of levodopa-induced dyskinesias (LID). Methods: The rat model of LID was treated with SCH 23390(1 mg/kg ip,a dopamine D1 antagonist) and haloperidol (1 mg/kg ip,a dopanfme D2 antagonist) respectively. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the expression of NGFI-B mRNA in stiiatam and the behavior changes were observed. Resuits: After treatment with SCH23390, abnormal involuntary movement (AIM) in LID rats was decreased ( P 〈 0.05 ) and the expression of NGFI-B mRNA in striatum did not change significantly. After treatment with haloperidol, the changes of AIM in LID rats were not significant and the expression of NGFI-B mRNA was increased significantly( P 〈 0.01). Conclusion: LID is associated with over-expression of NGFI-B in striatum. Abnormal activity in the direct pathway and the basal ganglia circuit could be involved in the occurrence of LID.
基金the Swedish Research Council(2018-02667)the National Natural Science Foundation of China(31761133015,U1704281,81901335)+3 种基金the Swedish Childhood Cancer Foundation(PR2018-0082)Swedish Governmental Grants to Scientists Working in Health Care(ALFGBG-717791)the Swedish Brain Foundation(FO2018-0034)the Chinese Scholarship Council to TL(201707040025)and to YX(201507040082)。
文摘Perinatal complications,such as asphyxia,can cause brain injuries that are often associated with subsequent neurological deficits,such as cerebral palsy or mental retardation.The mechanisms of perinatal brain injury are not fully understood,but mitochondria play a prominent role not only due to their central function in metabolism but also because many proteins with apoptosis-related functions are located in the mitochondrion.Among these proteins,apoptosis-inducing factor has already been shown to be an important factor involved in neuronal cell death upon hypoxia-ischemia,but a better understanding of the mechanisms behind these processes is required for the development of more effective treatments during the early stages of perinatal brain injury.In this review,we focus on the molecular mechanisms of hypoxic-ischemic encephalopathy,specifically on the importance of apoptosis-inducing factor.The relevance of apoptosis-inducing factor is based not only because it participates in the caspase-independent apoptotic pathway but also because it plays a crucial role in mitochondrial energetic functionality,especially with regard to the maintenance of electron transport during oxidative phosphorylation and in oxidative stress,acting as a free radical scavenger.We also discuss all the different apoptosis-inducing factor isoforms discovered,focusing especially on apoptosis-inducing factor 2,which is only expressed in the brain and the functions of which are starting now to be clarified.Finally,we summarized the interaction of apoptosis-inducing factor with several proteins that are crucial for both apoptosis-inducing factor functions(prosurvival and pro-apoptotic)and that are highly important in order to develop promising therapeutic targets for improving outcomes after perinatal brain injury.
文摘BACKGROUND: Therapeutic angiogenesis has opened up new pathway for the treatment of ischemic cerebrovascular disease in recent years. The exploration of the effect of vascular endothelial growth factor (VEGF) on inducing angiogenesis following ischemia/reperfusion injury can provide better help for the long-term treatment of cerebrovascular disease in clinic. OBJECTIVE: To observe the effect of VEGF on inducing angiogenesis following focal cerebral ischemia /reperfusion injury in rabbits through the angiogenesis of microvessels reflected by the expression of the factors of vascular pseudohemophilia. DESIGN: A randomized controlled animal tria SETTNG: Department of Medical Imaging, Second Hospital of Hebei Medical University MATERIALS: Sixty-five healthy male New Zealand rabbits of clean degree, weighing (2.6±0.2) kg, aged 4.5-5 months, were used. The polyclonal antibody against vascular pseudohemophilia (Beijing Zhongshan Company), recombinant VEGF165 (Peprotech Company, USA), biotinylated second antibody and ABC compound (Wuhan Boster Company) were applied. METHODS: The experiments were carried out in the Laboratory of Neuromolecular Imaging and Neuropathy, Second Hospital of Hebei Medical University from May to August in 2005. (1) The rabbits were randomly divided into three groups: sham-operated group (n=15), control group (n=25) and VEGF-treated group (n=-25). In the control group and VEGF-treated group, models were established by middle cerebral artery occlusion (MCAO) induced focal cerebral ischemia/reperfusion. In the VEGF-treated group, VEGF165 (2.5 mg/L) was stereotactically injected into the surrounding regions of the infarcted sites immediately after the 2-hour ischemia/reperfusion; Saline of the same dosage was injected in the control group. But the rabbits in the sham-operated group were only drilled but not administrated. (2) The experimental indexes were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment respectively, 3 rabbits in the sham-operated group and 5 in the control group and VEGF-treated group were observed at each time point. The brain tissues in the surrounding regions of the infarcted sites were collected. The positive expressions of the factors of vascular pseudohemophilia in vascular endothelial cells were analyzed with immunohistochemical method. The microvessels in unit statistical field were counted with the imaging analytical software. MAIN OUTCOME MEASURES: The changes of microvascular density in the brain tissue and the positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of the infarcted sites were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment. RESULTS: All the 65 New Zealand rabbits were involved in the analysis of results without deletion. Changes of the number of microvessels at different time points in each group: There were no obvious changes at different time points in the sham-operated group. The numbers of microvessels at 7 and 14 days were obviously more in the control group than in the sham-operated group [(6.0±1.1), (9.0±0.9) microvessels; (3.0±1.1), (3.0±1.1) microvessels; P〈 0.05-0.01], and those at 3, 7, 14 and 28 days were obviously more in the VEGF-treated group than in the control group [(8.3±2.0), (13.4±1.4), (15.5±2.3), (6.8± 1.0) microvessels; (3.4±0.6), (6.0±1.1), (9.0±0.9), (3.2±0.8) microvessels; P 〈 0.01]. (2) Positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of infarcted sites: There were no obvious changes at different time points in the sham-operated group. In the control group, the changing law of the expressions was the same as that for the number of microvessels that the expression began to mildly increase at 7 days, reached the peak value at 14 days, and began to reduce at 28 days. In the VEGF-treated group, the expression was obviously increased at 3 days, also reached the peak value at 14 days, and reduced to the normal level at 70 days, but the expressions were obviously stronger than those in the control group at the same time points. CONCLUSION: Angiogenesis can be obviously induced in rabbits after the focal cerebral ischemia/reperfusion injury is treated with VEGF for 18 days.
文摘The defining neuropathological feature of Parkinson's disease (PD) is the loss of nigrostriatal dopaminergic (DA) projections. This results in striatal dopamine levels and a biochemical reduction of movement disorders, such as a tremor at rest, rigidity of the limbs, bradykinesia, and postural instability (Kim et al., 2011; Kim et al., 2012; Burke and O'Malley, 2013; Leem et al., 2014; Namet al., 2014).
基金supported by the National Science Foundation CAREER Award CBET-0133775 and CBET-0754158,REU grant,and graduate fellowship from the CUNY
文摘Introduction Thrombosis is the formation of a blood clot in a blood vessel. When thrombosis happens in the brain,it would cause stroke; when happens in the heart,it would cause heart attack. If a thrombus breaks and travels to the lung,it would
基金Key Program of Tenth Five-Year Plan and the 211 Key Subject Construction Foundation, No. 2002-2
文摘BACKGROUND: Receptors for tumor necrosis factor related apoptosis inducing ligand (TRAIL) include death receptor 4, death receptor 5, decoy receptor 1, and decoy receptor 2. Activation of death receptor 4 and 5 selectively kills tumor cells. OBJECTIVE: To detect TRAIL receptor expression in glioblastoma by immunohistochemistry and RT-PCR, and to compare this expression to that in normal brain tissue. DESIGN: Observational analysis. SETTING: Department of Pathology, the First Affiliated Hospital of Zhengzhou University; Henan Tumor Pathology Key Laboratory. PARTICIPANTS: Twenty-five patients (17 males and 8 females) who received glioblastoma resection were selected from the Fifth Affiliated Hospital of Zhengzhou University, between September 2003 to June 2004. All glioblastoma samples were diagnosed pathologically. Twenty patients (12 males and 8 females) with craniocerebral injury who received normal brain tissue resection were selected in the same time period. There were no significant differences in sex and age between glioblastoma patients or between craniocerebral injury patients (P 〉 0.05). All patients and appropriate relatives provided informed consent, and this study was approved by the local research ethics committee. METHODS: Polyclonal antibody against TRAIL receptors and an immunohistochemical kit (batch number: 200502) were purchased from Boster Company, Wuhan. Immunohistochemistry: Expression of death receptor 4, death receptor 5, decoy receptor l, and decoy receptor 2 were observed in both glioblastoma and normal brain tissue. The experiment was performed according to the kit instructions, and positive staining was brown-yellow. Assessment: There were no positive signals (-); weakly positive signals, positive cells 〈 25% (+); weakly positive signals, positive cells 25%-50% (++); strongly positive signals, positive cells 50%-75% (+++); strongly positive signals, positive cells 〉 75% (++++). Evaluation: Expression levels of TRAIL receptors were estimated in both normal brain tissue and glioblastoma. Expression of decoy receptor 1 and decoy receptor 2 mRNA in glioblastoma were detected by reverse transcription polymerase chain reaction, and expression of decoy receptor in glioblastoma was estimated. MAIN OUTCOME MEASURES: Comparison of death receptor and decoy receptor protein expression between glioblastoma and normal brain tissue; decoy receptor mRNA expression in glioblastoma. RESULTS: Death receptor protein expression was strongly positive (+++) in glioblastoma, while it was weakly positive (+, ++) in normal brain tissue. Therefore, expression rate of death receptor protein in the glioblastoma was significantly higher than that in the normal brain tissue (.~ 2 = 18.48, 23.03, P 〈 0.01). Decoy receptor protein expression in the glioblastoma was significantly lower than that in the normal brain tissue ( x2 = 6.65, 18.76, P 〈 0.01). The level of decoy receptor mRNA expression in glioblastoma was significantly higher than those of protein expression ( x 2 = 9.82, 10.09, P〈 0.01). CONCLUSION: High expression of death receptor and low expression of decoy receptor are frequently observed in glioblastoma, suggesting that TRAIL receptor genes show an anti-tumor and expressive response during the initiation and development of the tumor. There are significant differences in decoy receptor expression between normal brain tissue and glioblastoma, suggesting that the restricted expression of decoy receptor in glioblastoma is regulated at the post-transcriptional level.