Hypoxia-inducible factor 1alpha and vascular endothelial growth factor in Glioblastoma Multiforme:a systematic review going beyond pathologic implications

Glioblastoma multiforme(GBM)is an aggressive primary brain tumor characterized by extensive heterogeneity and vascular proliferation.Hypoxic conditions in the tissue microenvironment are considered a pivotal player leading tumor progression.Specifically,hypoxia is known to activate inducible factors,such as hypoxia-inducible factor 1alpha(HIF-1α),which in turn can stimulate tumor neo-angiogenesis through activation of various downward mediators,such as the vascular endothelial growth factor(VEGF).Here,we aimed to explore the role of HIF-1α/VEGF immunophenotypes alone and in combination with other prognostic markers or clinical and image analysis data,as potential biomarkers of GBM prognosis and treatment efficacy.We performed a systematic review(Medline/Embase,and Pubmed database search was completed by 16th of April 2024 by two independent teams;PRISMA 2020).We evaluated methods of immunoassays,cell viability,or animal or patient survival methods of the retrieved studies to assess unbiased data.We used inclusion criteria,such as the evaluation of GBM prognosis based on HIF-1α/VEGF expression,other biomarkers or clinical and imaging manifestations in GBM related to HIF-1α/VEGF expression,application of immunoassays for protein expression,and evaluation of the effectiveness of GBM therapeutic strategies based on HIF-1α/VEGF expression.We used exclusion criteria,such as data not reporting both HIF-1αand VEGF or prognosis.We included 50 studies investigating in total 1319 GBM human specimens,18 different cell lines or GBM-derived stem cells,and 6 different animal models,to identify the association of HIF-1α/VEGF immunophenotypes,and with other prognostic factors,clinical and macroscopic data in GBM prognosis and therapeutic approaches.We found that increased HIF-1α/VEGF expression in GBM correlates with oncogenic factors,such as miR-210-3p,Oct4,AKT,COX-2,PDGF-C,PLDO3,M2 polarization,or ALK,leading to unfavorable survival.Reduced HIF-1α/VEGF expression correlates with FIH-1,ADNP,or STAT1 upregulation,as well as with clinical manifestations,like epileptogenicity,and a favorable prognosis of GBM.Based on our data,HIF-1αor VEGF immunophenotypes may be a useful tool to clarify MRI-PET imaging data distinguishing between GBM tumor progression and pseudoprogression.Finally,HIF-1α/VEGF immunophenotypes can reflect GBM treatment efficacy,including combined first-line treatment with histone deacetylase inhibitors,thimerosal,or an active metabolite of irinotecan,as well as STAT3 inhibitors alone,and resulting in a favorable tumor prognosis and patient survival.These data were supported by a combination of variable methods used to evaluate HIF-1α/VEGF immunophenotypes.Data limitations may include the use of less sensitive detection methods in some cases.Overall,our data support HIF-1α/VEGF’s role as biomarkers of GBM prognosis and treatment efficacy.

Hypoxia-inducible factor-1αin myocardial infarction

Hypoxia-inducible factor 1(HIF1)has a crucial function in the regulation of oxygen levels in mammalian cells,especially under hypoxic conditions.Its importance in cardiovascular diseases,particularly in cardiac ischemia,is because of its ability to alleviate cardiac dysfunction.The oxygen-responsive subunit,HIF1α,plays a crucial role in this process,as it has been shown to have cardioprotective effects in myocardial infarction through regulating the expression of genes affecting cellular survival,angiogenesis,and metabolism.Furthermore,HIF1αexpression induced reperfusion in the ischemic skeletal muscle,and hypoxic skin wounds in diabetic animal models showed reduced HIF1αexpression.Increased expression of HIF1αhas been shown to reduce apoptosis and oxidative stress in cardiomyocytes during acute myocardial infarction.Genetic variations in HIF1αhave also been found to correlate with altered responses to ischemic cardiovascular disease.In addition,a link has been established between the circadian rhythm and hypoxic molecular signaling pathways,with HIF1αfunctioning as an oxygen sensor and circadian genes such as period circadian regulator 2 responding to changes in light.This editorial analyzes the relationship between HIF1αand the circadian rhythm and highlights its significance in myocardial adaptation to hypoxia.Understanding the changes in molecular signaling pathways associated with diseases,specifically cardiovascular diseases,provides the opportunity for innovative therapeutic interventions,especially in low-oxygen environments such as myocardial infarction.

电针调控HIF-1α/VEGF信号通路对类风湿性关节炎模型踝关节病理学改变的影响

目的探讨电针通过调控HIF-1α/VEGF信号通路活性对类风湿性关节炎(RA)大鼠踝关节病理损伤的影响。方法选取50只SD大鼠,随机分为Sham组(空白对照)、RA组(大鼠构建RA模型)、电针组(RA组大鼠给予电针治疗)、CAY10585组(RA大鼠腹腔内注射HIF-1α/VEGF信号通路抑制剂)、电针+CAY10585组(电针组大鼠腹腔注射HIF-1α/VEGF信号通路抑制剂),每组10只。模型建立后观察各组大鼠基本形态;8周后处死大鼠,比较治疗后大鼠踝关节直径;取大鼠踝关节行HE染色,观察整体病理形态及踝关节病理特征(滑膜细胞增殖、细胞侵蚀、血管翳形成、炎性细胞浸润、骨侵蚀)病理评分;酶联免疫吸附法(ELISA)检测5组大鼠血清炎性因子肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)水平;Western-blot检测大鼠踝关节组织内软骨基质因子Ⅱ型胶原(CollagenⅡ)、C端肽(CTXⅡ)、Ⅱ型胶原C前肽(CPⅡ)蛋白表达。结果与Sham组比较,RA模型建立可以上调大鼠踝关节直径,踝关节滑膜细胞增殖、细胞侵蚀、血管翳形成、炎性细胞浸润、骨侵蚀病理评分,血清炎性因子(TNF-α、IL-6)水平均明显提升(P<0.05),关节滑膜上皮复层出现增生、间质水肿以及炎性细胞浸润的现象;电针干预可以下调大鼠踝关节直径、踝关节滑膜细胞增殖、细胞侵蚀、血管翳形成、炎性细胞浸润、骨侵蚀病理评分,血清炎性因子(TNF-α、IL-6)水平(P<0.05),同时踝关节病理形态明显得到缓解;CAY10585干预再次增加RA大鼠病理形态,破骨细胞明显增加,骨质出现侵蚀、溶解骨层及炎性细胞浸润的现象,踝关节直径、踝关节滑膜细胞增殖、细胞侵蚀、血管翳形成、炎性细胞浸润、骨侵蚀病理评分,血清炎性因子(TNF-α、IL-6)水平再次提升(P<0.05);电针干预可以逆转CAY10585组大鼠趋势,再次下调大鼠踝关节直径、踝关节滑膜细胞增殖、细胞侵蚀、血管翳形成、炎性细胞浸润、骨侵蚀病理评分(P<0.05);与Sham组比较,RA组大鼠踝关节组织内CTXⅡ表达提升,CollagenⅡ、CPⅡ表达降低(P<0.05);电针干预可以下调CTXⅡ表达,上调CollagenⅡ、CPⅡ、HIF-1α、VEGF表达(P<0.05);CAY10585干预则体现出相反趋势,再次上调CTXⅡ表达,下调CollagenⅡ、CPⅡ、HIF-1α、VEGF表达(P<0.05);电针干预可以逆转CAY10585组大鼠软骨基质及HIF-1α、VEGF表达(P<0.05)。结论电针治疗可以改善RA大鼠踝关节的病理学表现,降低炎性反应,保护软骨损伤,其分子机制可能与激活HIF-1α/VEG信号通路有关。

热应激对从江香猪十二指肠黏膜结构、HIF-1及其相关蛋白表达的影响

旨在研究热应激(heat stress,HS)对从江香猪十二指肠黏膜屏障结构的影响,同时跟踪检测低氧诱导因子-1(hypoxia inducible factor-1,HIF-1)的表达特征及调控机制。试验选取24头育肥期从江香猪,随机分为6组,除对照组(Con),其余5组进行不同时间热应激处理(6、12、24、48、72 h),试验过程中检测从江香猪直肠温度和呼吸频率,试验结束时采集各组从江香猪十二指肠。苏木精-伊红染色(HE)和阿利新蓝-过碘酸雪夫反应(AB-PAS)观察各组十二指肠组织结构和杯状细胞数量变化;TUNEL染色检测十二指肠细胞凋亡率;实时荧光定量(qRTPCR)、蛋白免疫印迹(Western blot)和免疫组织化学分别检测紧密连接相关蛋白、HIF-1及其上游调控因子HSP90和PHD-2的表达变化。结果显示,与对照组相比,热应激可使从江香猪直肠温度和呼吸频率明显升高,肠绒毛高度下降,隐窝深度增加,绒腺比降低,闭合蛋白(Occludin)和紧密连接蛋白1(ZO-1)表达水平呈时间依赖性下降,杯状细胞数量增多。TUNEL检测结果显示,HS处理72 h后,十二指肠上皮细胞凋亡率显著上升(P<0.001)。免疫组织化学、qRT-PCR和Western blot对HIF-1α、HSP90和PHD-2的表达进行检测,结果显示,相较于对照组,HS处理72 h后十二指肠黏膜上皮HIF-1αmRNA和蛋白表达量随HS时间延长而增加;HSP90阳性细胞在对照组和热应激组中均集中于黏膜上皮,其表达趋势与HIF-1α一致;PHD-2表达特征与HSP90相反,其表达强度在HS组中明显减弱,且随HS时间增加,PHD-2 mRNA和蛋白水平均呈时间依赖性下降。以上结果说明,HS可引起十二指肠上皮细胞凋亡,损伤十二指肠黏膜屏障;HIF-1的表达升高与十二指肠细胞凋亡密切相关,且可能同时受HSP90和PHD-2调控。

Association of hypoxia-inducible factor-1α (HIF1α) 1772C/T genepolymorphism with susceptibility to renal cell carcinoma/prostatecancer

In this study,we used a meta-analysis method to evaluate the relationship between hypoxia-inducible factor-1α(HIF1α)1772C/T gene polymorphism(rs 11549465)and renal cell carcinoma(RCC)/prostate cancer risk.We searched for relevant studies(before March 1,2019)on Cochrane Library,Embase,and PubMed.Studies meeting the inclusion criteria were recruited into this meta-analysis.The outcome of dichotomous data was showed in the way of odds ratios(OR),and 95%confidence intervals(CI)were also counted.In this investigation,there was no association between HIF1α1772C/T gene polymorphism and susceptibility to RCC in Caucasians,Asians as well as overall populations.In addition,HIF1α1772C/T gene polymorphism was not found to be relevant to the survival in RCC.Interestingly,the T allele was relevant to prostate cancer risk in all populations,but not in Caucasians and Asians.However,the TT genotype and the CC genotype were not related to prostate cancer susceptibility in Asian,Caucasian,and all populations.In conclusion,the T allele of the HIF1α1772C/T gene polymorphism was related to prostate cancer risk in the overall populations.

原发性肝癌患者血清HIF-1α、TK1、γ-GT水平与TACE治疗预后的关系

目的探索血清缺氧诱导因子-1α(HIF-1α)、胸苷激酶1(TK1)、γ-谷氨酰转移酶(γ-GT)对原发性肝癌患者经肝动脉导管化疗栓塞术(TACE)治疗预后的预测价值。方法选取2019年10月至2022年10月接受TACE治疗的172例原发性肝癌患者作为癌症组,同期选择156例健康体检者作为对照组。采用酶联免疫吸附法(ELISA)检测血清HIF-1α、TK1水平,采用全自动分析仪检测血清γ-GT水平;分析血清HIF-1α、TK1、γ-GT水平与患者临床病理特征的关系;对原发性肝癌患者TACE治疗后预后不良的影响因素进行单因素及多因素分析;受试者工作特征(ROC)曲线分析血清HIF-1α、TK1、γ-GT检测对原发性肝癌患者TACE治疗后预后不良的预测价值。结果癌症组患者血清HIF-1α、TK1、γ-GT水平高于对照组(P<0.001),患者血清HIF-1α、TK1、γ-GT水平与血管侵犯、肿瘤直径及病灶数目相关(P<0.05或0.001);血清HIF-1α、TK1、γ-GT是患者预后不良的影响因素(P<0.05或0.001);血清HIF-1α、TK1、γ-GT联合预测患者预后不良的ROC曲线下面积(AUC)显著大于HIF-1α单独预测的AUC(Z=2.712,P=0.007),TK1单独预测的AUC(Z=3.642,P<0.001),γ-GT单独预测的AUC(Z=3.347,P<0.001)。结论原发性肝癌患者TACE治疗后血清HIF-1α、TK1、γ-GT水平升高,联合检测其水平对患者预后不良具有较好的预测价值。

Effects of hypoxia-inducible factor-1α silencing on the proliferation of CBRH-7919 hepatoma cells

AIM:To study the effects of hypoxia-inducible factor1α(HIF-1α) silencing on the proliferation of hypoxic CBRH-7919 rat hepatoma cells.METHODS:The CBRH-7919 rat hepatoma cell line was used in this study and the hypoxic model was constructed using CoCl2.The HIF-1α-specific RNAi sequences were designed according to the gene coding sequence of rat HIF-1α obtained from GeneBank.The secondary structure of the HIF-1α gene sequence was analyzed using RNA draw software.The small interfering RNA(siRNA) transfection mixture was produced by mixing the siRNA and Lipofectamine2000TM,and transfected into the hypoxic hepatoma cells.Real time reverse transcription-polymerase chain reaction(RTPCR) and Western blotting assay were used to detect the expression levels of mRNA and protein.HIF-1α and vascular endothelial growth factor(VEGF) mRNA was determined using real time RT-PCR;the protein expression levels of AKT,p-AKT,p21 and cyclinD1 were determined using Western blotting.The proliferation of hepatoma cells was observed using the methyl thiazolyl tetrazolium(MTT) assay and the bromodeoxyuridine(BrdU) incorporation cell proliferation assay.RESULTS:Under induced hypoxia,the viability of the hepatoma cells reached a minimum at 800 μmol/L CoCl2;the viability of the cells was relatively high at CoCl2 concentrations between 100 μmol/L and 200 μmol/L.Under hypoxia,the mRNA and protein expression levels of HIF-1α and VEGF were significantly higher than that of hepatoma cells that were cultured in normaxia.HIF-1α-specific RNAi sequences were successfully transfected into hepatoma cells.The transfection of specific siRNAs significantly inhibited the mRNA and protein expression levels of HIF-1α and VEGF,along with the protein expression levels of p-AKT and cyclinD1;the protein expression of p21 was significantly increased,and there was no significant difference in the expression of AKT.The MTT assay showed that the amount of hepatoma cells in S phase in the siRNA transfection group was obviously smaller than that in the control group;in the siRNA transfection group,the amount of hepatoma cells in G1 phase was more than that in the control group.The BrdU incorporation assay showed that the number of BrdU positive hepatoma cells in the siRNA transfection group was less than that in the control group.The data of the MTT assay and BrdU incorporation assay suggested that HIF-1α silencing using siRNAs significantly inhibited the proliferation of hepatoma cells.CONCLUSION:Hypoxia increases the expression of HIF-1α,and HIF-1α silencing significantly inhibits the proliferation of hypoxic CBRH-7919 rat hepatoma cells.

Early expressions of hypoxia-inducible factor 1alpha and vascular endothelial growth factor increase the neuronal plasticity of activated endogenous neural stem cells after focal cerebral ischemia

Endogenous neural stem cells become ＂activated＂ after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry and western blot analysis. We also evaluated the chronological changes of neural stem cells by 5-bromo-2′-deoxyuridine（BrdU） incorporation. Hypoxia-inducible factor-1α expression was initially increased from 1 hour after ischemic injury, followed by vascular endothelial growth factor expression. Hypoxia-inducible factor-1α immunoreactivity was detected in the ipsilateral cortical neurons of the infarct core and peri-infarct area. Vascular endothelial growth factor immunoreactivity was detected in bilateral cortex, but ipsilateral cortex staining intensity and numbers were greater than the contralateral cortex. Vascular endothelial growth factor immunoreactive cells were easily found along the peri-infarct area 12 hours after focal cerebral ischemia. The expression of nestin increased throughout the microvasculature in the ischemic core and the peri-infarct area in all experimental rats after 24 hours of ischemic injury. Nestin immunoreactivity increased in the subventricular zone during 12 hours to 3 days, and prominently increased in the ipsilateral cortex between 3–7 days. Nestin-labeled cells showed dual differentiation with microvessels near the infarct core and reactive astrocytes in the peri-infarct area. BrdU-labeled cells were increased gradually from day 1 in the ipsilateral subventricular zone and cortex, and numerous BrdU-labeled cells were observed in the peri-infarct area and non-lesioned cortex at 3 days. BrdU-labeled cells rather than neurons, were mainly co-labeled with nestin and GFAP. Early expressions of hypoxia-inducible factor-1α and vascular endothelial growth factor after ischemia made up the microenvironment to increase the neuronal plasticity of activated endogenous neural stem cells. Moreover, neural precursor cells after large-scale cortical injury could be recruited from the cortex nearby infarct core and subventricular zone.

miR-519d-3p靶向HIF-1α抑制高糖诱导的人视网膜微血管内皮细胞功能障碍及血管生成

目的:明确miR-519d-3p对高糖诱导的人视网膜微血管内皮细胞(HRMEC)功能障碍与血管生成的影响,并阐明其对低氧诱导因子-1α(HIF-1α)的调控机制。方法:通过5、30mmol/L葡萄糖分别诱导HRMEC建立正常(NG)和高糖(HG)细胞模型。将HRMEC分为对照组(HG细胞模型转染阴性对照模拟物)、甘露醇组(对照组加入25mmol/L甘露醇)、miR-519d-3p过表达组(HG细胞模型转染miR-519d-3p模拟物)、miR-519d-3p联合HIF-1α过表达组(HG细胞模型共转染miR-519d-3p模拟物和HIF-1α过表达载体)。实时荧光定量PCR法检测各组miR-519d-3p的表达情况。Western blotting法检测各组HIF-1α蛋白的表达情况。荧光素酶报告基因实验检测miR-519d-3p和HIF-1α的结合位点情况。CCK-8法检测各组细胞增殖情况。Hoechst 33342染色法检测各组细胞凋亡情况。ELISA法检测各组细胞外液炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6蛋白的表达情况。小管形成实验检测各组新生毛细血管管腔样结构形成情况。结果:与NG相比,HG细胞模型中miR-519d-3p表达显著减少,而HIF-1α蛋白表达显著增加(均P<0.01)。与对照组比较,miR-519d-3p过表达组中HIF-1α蛋白表达显著降低(P<0.01)。miR-519d-3p中“CGUGAAA”序列可以与HIF-1α3'-非编码区(3'-UTR)中“GCACUUU”序列特异性结合。与对照组比较,miR-519d-3p过表达组细胞24、48、72h吸光度值均显著增加,细胞凋亡率显著减少,细胞外液TNF-α、IL-1β、IL-6浓度均显著减少,新生毛细血管管腔样结构数量显著减少(均P<0.01)。与miR-519d-3p过表达组比较,miR-519d-3p联合HIF-1α过表达组细胞24、48、72h吸光度值均显著减少,细胞凋亡率显著增加,细胞外液TNF-α、IL-1β、IL-6浓度均显著增加,新生毛细血管管腔样结构数量显著增加(均P<0.01)。对照组和甘露醇组中上述各指标比较无差异(均P>0.05)。结论:高糖诱导HRMEC模型中miR-519d-3p表达下调,而HIF-1α蛋白表达上调。HIF-1α是miR-519d-3p的靶基因,miR-519d-3p靶向HIF-1α增加细胞增殖并降低细胞凋亡和炎症反应,从而减轻高糖诱导的HRMEC功能障碍并抑制血管生成。

Lysyl oxidase and hypoxia-inducible factor 1α: biomarkers of gastric cancer

BACKGROUND Gastric cancer(GC) is one of the main causes of cancer mortality worldwide.Recent studies on tumor microenvironments have shown that tumor metabolism exerts a vital role in cancer progression.AIM To investigate whether lysyl oxidase(LOX) and hypoxia-inducible factor 1α(HIF1α) are prognostic and predictive biomarkers in GC.METHODS A total of 80 tissue and blood samples were collected from 140 patients admitted to our hospital between August 2008 and March 2012. Immunohistochemical staining was performed to measure the expression of LOX and HIF1α in tumor and adjacent tissues collected from patients with GC. Real-time quantitative reverse transcription polymerase chain reaction(qRT-PCR) analysis was used to detect the mRNA expression levels of LOX and HIF1α in patients with GC. In addition, single-factor analysis was applied to analyze the relationship between LOX, HIF1α and prognosis of GC.RESULTS Immunohistochemical staining suggested that the expression levels of LOX and HIF1α increased in tumor tissues from patients with GC. QRT-PCR analysis indicated that mRNA expression of LOX and HIF1α was also upregulated in tumor tissues, which was in accordance with the above results. We also detected expression of these two genes in blood samples. The expression level of LOX and HIF1α was higher in patients with GC than in healthy controls. Additional analysis showed that the expression level of LOX and HIF1α was related to the clinicopathological characteristics of GC. Expression of LOX and HIF1α increased with the number of lymph node metastases, deeper infiltration depth and later tumor–node–metastasis stages. Single-factor analysis showed that high expression of LOX and HIF1α led to poor prognosis of patients with GC.CONCLUSION LOX and HIF1α can be used as prognostic and predictive biomarkers for GC.

The hypoxia-inducible factor-1α activates ectopic production of fibroblast growth factor 23 in tumor-induced osteomalacia

Tumor-induced osteomalacia （TIO） is a rare paraneoplastic syndrome in which ectopic production of fibroblast growth factor 23 （FGF23） by non-malignant mesenchymal tumors causes phosphate wasting and bone fractures. Recent studies have implicated the hypoxia-inducible factor-la （HIF-la） in other phosphate wasting disorders caused by elevated FGF23, including X-linked hypophosphatemic rickets and autosomal dominant hypophosphatemia. Here we provide evidence that HIF-la mediates aberrant FGF23 in TIO by transcriptionally activating its promoter. Immunohistochemical studies in phosphaturic mesenchymal tumors resected from patients with documented TIO showed that HIF-la and FGF23 were co-localized in spindle- shaped cells adjacent to blood vessels. Cultured tumor tissue produced high levels of intact FGF23 and demonstrated increased expression of HIF-la protein. Transfection of MC3T3-E1 and Saos-2 cells with a HIF-la expression construct induced the activity of a FGF23 reporter construct. Prior treatment of tumor organ cultures with HIF-la inhibitors decreased HIF-la and FGF23 protein accumulation and inhibited HIF-la-induced luciferase reporter activity in transfected cells. Chromatin immunoprecipitation assays confirmed binding to a HIF-la consensus sequence within the proximal FGF23 promoter, which was eliminated by treatment with a HIF-la inhibitor. These results show for the first time that HIF-la is a direct transcriptional activator of FGF23 and suggest that upregulation of HIF-la activity in TIO contributes to the aberrant FGF23 production in these patients.

Effect of lentiviral vector-mediated overexpression of hypoxia-inducible factor 1 alpha delivered by pluronic F-127 hydrogel on brachial plexus avulsion in rats

Brachial plexus avulsion often results in massive motor neuron death and severe functional deficits of target muscles. However, no satisfactory treatment is currently available. Hypoxia-inducible factor 1α is a critical molecule targeting several genes associated with ischemia-hypoxia damage and angiogenesis. In this study, a rat model of brachial plexus avulsion-reimplantation was established, in which C5–7 ventral nerve roots were avulsed and only the C6 root reimplanted. Different implants were immediately injected using a microsyringe into the avulsion-reimplantation site of the C6 root post-brachial plexus avulsion. Rats were randomly divided into five groups: phosphate-buffered saline, negative control of lentivirus, hypoxia-inducible factor 1α(hypoxia-inducible factor 1α overexpression lentivirus), gel(pluronic F-127 hydrogel), and gel + hypoxia-inducible factor 1α(pluronic F-127 hydrogel + hypoxia-inducible factor 1α overexpression lentivirus). The Terzis grooming test was performed to assess recovery of motor function. Scores were higher in the hypoxia-inducible factor 1α and gel +hypoxia-inducible factor 1α groups(in particular the gel + hypoxia-inducible factor 1α group) compared with the phosphate-buffered saline group. Electrophysiology, fluorogold retrograde tracing, and immunofluorescent staining were further performed to investigate neural pathway reconstruction and changes of neurons, motor endplates, and angiogenesis. Compared with the phosphate-buffered saline group, action potential latency of musculocutaneous nerves was markedly shortened in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor1α groups. Meanwhile, the number of fluorogold-positive cells and ChAT-positive neurons, neovascular area(labeled by CD31 around av ulsed sites in ipsilateral spinal cord segments), and the number of motor endplates in biceps brachii(identified by α-bungarotoxin) were all visibly increased, as well as the morphology of motor endplate in biceps brachil was clear in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor 1α groups. Taken together, delivery of hypoxia-inducible factor 1α overexpression lentiviral vectors mediated by pluronic F-127 effectively promotes spinal root regeneration and functional recovery post-brachial plexus avulsion. All animal procedures were approved by the Institutional Animal Care and Use Committee of Guangdong Medical University, China.

Extracellular vesicles from hypoxia-preconditioned mesenchymal stem cells alleviates myocardial injury by targeting thioredoxininteracting protein-mediated hypoxia-inducible factor-1αpathway

BACKGROUND Extracellular vesicles(EVs)derived from hypoxia-preconditioned(HP)mesenchymal stem cells(MSCs)have better cardioprotective effects against myocardial infarction(MI)in the early stage than EVs isolated from normoxic(NC)-MSCs.However,the cardioprotective mechanisms of HP-EVs are not fully understood.AIM To explore the cardioprotective mechanism of EVs derived from HP MSCs.METHODS We evaluated the cardioprotective effects of HP-EVs or NC-EVs from mouse adipose-derived MSCs(ADSCs)following hypoxia in vitro or MI in vivo,in order to improve the survival of cardiomyocytes(CMs)and restore cardiac function.The degree of CM apoptosis in each group was assessed by the terminal deoxynucleotidyl transferase dUTP nick end-labeling and Annexin V/PI assays.MicroRNA(miRNA)sequencing was used to investigate the functional RNA diversity between HP-EVs and NC-EVs from mouse ADSCs.The molecular mechanism of EVs in mediating thioredoxin-interacting protein(TXNIP)was verified by the dual-luciferase reporter assay.Co-immunoprecipitation,western blotting,and immunofluorescence were performed to determine if TXNIP is involved in hypoxia-inducible factor-1 alpha(HIF-1α)ubiquitination and degradation via the chromosomal region maintenance-1(CRM-1)-dependent nuclear transport pathway.RESULTS HP-EVs derived from MSCs reduced both infarct size(necrosis area)and apoptotic degree to a greater extent than NC-EVs from CMs subjected to hypoxia in vitro and mice with MI in vivo.Sequencing of EV-associated miRNAs showed the upregulation of 10 miRNAs predicted to bind TXNIP,an oxidative stress-associated protein.We showed miRNA224-5p,the most upregulated miRNA in HP-EVs,directly combined the 3’untranslated region of TXNIP and demonstrated its critical protective role against hypoxia-mediated CM injury.Our results demonstrated that MI triggered TXNIP-mediated HIF-1αubiquitination and degradation in the CRM-1-mediated nuclear transport pathway in CMs,which led to aggravated injury and hypoxia tolerance in CMs in the early stage of MI.CONCLUSION The anti-apoptotic effects of HP-EVs in alleviating MI and the hypoxic conditions of CMs until reperfusion therapy may partly result from EV miR-224-5p targeting TXNIP.

Clinicopathological and Prognostic Significance of Hypoxia-inducible Factor-1 alpha in Lung Cancer: a Systematic Review with Meta-analysis

Hypoxia-inducible factor-1 alpha（HIF-1α） plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a meta-analysis was implemented to further understand the prognostic role of HIF-1α in lung cancer. The relationship between HIF-1α and the clinicopathological characteristics and prognosis of lung cancer were investigated by a meta-analysis. Pub Med and Embase were searched from their inception to January 2015 for observational studies. Fixed-effects or random-effects meta-analyses were used to calculate odds ratios and 95% confidence intervals of different comparisons. A total of 20 studies met the criteria. The results showed that HIF-1α expression in lung cancer tissues was significantly higher than that in normal lung tissues. Expression of HIF-1α in patients with squamous cell carcinoma was significantly higher than that of patients with adenocarcinomas. Similarly, non-small cell lung cancer（NSCLC） patients had higher HIF-1α expression than small cell lung cancer（SCLC） patients. Moreover, lymph node metastasized tissues had higher HIF-1α expression than non-lymph node metastasized tissues. A high level HIF-1α expression was well correlated with the expression of vascular endothelial growth factor and epidermal growth factor receptor in the NSCLC. Notably, NSCLC or SCLC patients with positive HIF-1α expression in tumor tissues had lower overall survival rate than patients with negative HIF-1α expression. It was suggested that HIF-1α expression may be a prognostic biomarker and a potential therapeutic target for lung cancer.

基于HIF-1信号通路基因变化探讨COPD肺血管病变的发生机制

目的以慢性阻塞性肺疾病(COPD)动物模型为基础,探索COPD肺血管病变发生发展与低氧诱导因子(HIF)-1复合信号通路的关系。方法将30只SD雄性大鼠随机分为正常组10只,模型组20只,模型组后续分为造模6 w组与造模12 w组。以香烟烟雾暴露结合鼻腔滴入内毒素法建立COPD模型,收集正常组、造模6、12 w组肺组织,q-聚合酶链反应(PCR)法检测COPD模型造模后不同时间点HIF-1复合通路关键基因HIF-1α、热休克蛋白(HSP)90、血管内皮生长因子(VEGF)、诱导型一氧化氮合酶(iNOS)及内皮素(ET)-1 mRNA表达。结果与正常组相比,COPD模型组黏膜下存在明显的炎细胞浸润,肺泡壁变薄或断裂引起部分肺泡扩大融合形成肺大泡,肺血管也显示出不同程度增生,管壁增厚或管腔变形,微血管数量明显增多。与正常组相比,造模6、12 w后肺组织中HIF-1α、HSP90、VEGF、ET-1 mRNA表达显著上调(P<0.05,P<0.01),且造模12 w后肺组织中HIF-1α、VEGF、iNOS mRNA表达与造模6 w时相比显著上调(P<0.05)。与造模6 w时相比,造模12 w后肺组织中HSP90、ET-1 mRNA表达无显著差异(P>0.05)。与正常组相比,肺组织中iNOS mRNA表达在造模6 w时无显著差异(P>0.05),造模12 w后肺组织中iNOS mRNA表达显著上调(P>0.05)。结论COPD肺血管病变的发生发展与HIF-1复合信号通路的表达相关,且严重程度与造模时长呈正相关。

Expression of hypoxia-inducible factor 1 alpha and oligodendrocyte lineage gene-1 in cultured brain slices after oxygen-glucose deprivation

Oligodendrocyte lineage gene-1 expressed in oligodendrocytes may trigger the repair of neuronal myelin impairment, and play a crucial role in myelin repair. Hypoxia-inducible factor la, a transcription factor, is of great significance in premature infants with hypoxic-ischemic brain damage There is little evidence of direct regulatory effects of hypoxia-inducible factor le on oligodendrocyte lineage gene-l. In this study, brain slices of Sprague-Dawley rats were cultured and subjected to oxygen-glucose deprivation. Then, slices were transfected with hypoxia-inducible factor la or oligodendrocyte lineage gene-1. The expression levels of hypoxia-inducible factor la and oligodendrocyte lineage gene-1 were significantly up-regulated in rat brains prior to transfection, as detected by immunohistochemical staining. Eight hours after transfection of slices with hypoxia-inducible factor la, oligodendrocyte lineage gene-1 expression was upregulated, and reached a peak 24 hours after transfection. Oligodendrocyte lineage gene-1 transfection induced no significant differences in hypoxia-inducible factor la levels in rat brain tissues with oxygen-glucose deprivation. These experimental findings indicate that hypoxia-inducible factor la can regulate oligodendrocyte lineage gene-1 expression in hypoxic brain tissue, thus repairing the neural impairment.

Hypoxia-inducible factor-1α–mediated upregulation of CD99 promotes the proliferation of placental mesenchymal stem cells by regulating ERK1/2

BACKGROUND As human placenta-derived mesenchymal stem cells(hP-MSCs)exist in a physiologically hypoxic microenvironment,various studies have focused on the influence of hypoxia.However,the underlying mechanisms remain to be further explored.AIM The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs.METHODS A hypoxic cell incubator(2.5%O2)was used to mimic a hypoxic microenvironment.Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs.The cell cycle was profiled by flow cytometry.Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing.CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction.Small interfering RNA-mediated hypoxia-inducible factor 1α(HIF-1α)or CD99 knockdown of hP-MSCs,luciferase reporter assays,and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis.Protein expression was assayed by western blotting;immunofluorescence assays were conducted to evaluate changes in expression levels.RESULTS Hypoxia enhanced hP-MSC proliferation,increased the expression of cyclin E1,cyclin-dependent kinase 2,and cyclin A2,and decreased the expression of p21.Under hypoxia,CD99 expression was increased by HIF-1α.CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation.CONCLUSION Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.

Increased hypoxia-inducible factor 1alpha expression in rat brain tissues in response to aging

The present study observed changes in rat neural cells at various ages （3, 18, 24, and 30 months）. With age, neural cells became large and were sparsely arranged, and the number of Nissl bodies decreased. In addition, hypoxia-inducible factor 1α expression increased with increasing age in hippocampal CA1 and CA3 regions, motor cortex, and the first subfolium, especially from 3 to 18 months. In the open-field test, grid crossing decreased with increasing age, especially from 18 months. The number of rearings reached a peak in the 18 months group, and then subsequently decreased. The results suggested that hypoxia-inducible factor 1α played an important role in the nervous system aging process.

Correlation between the Expression of Aquaporin 1 and Hypoxia-inducible Factor 1 in Breast Cancer Tissues

The correlation between aquaporin 1 （AQP1） and hypoxia-inducible factor 1 （HIF 1） in breast cancer tissues was preliminarily studied. In 155 cases of breast cancer, the expression levels of AQP1 were detected by immunohistochemisty in HIFl-positive group or HIFl-negative group, and the correlation between AQP1 and HIF1 was analyzed. The overexpression of AQP1 and HIF1 were observed in 155 cases of breast cancer tissues. The expression level of AQP1 in HIFl-positive group was significantly higher than that in HIFl-negative group. The positive expression rate of AQP1 was 296.55±24.67 and 168.37±37.53 in HIFl-positive group and HIFl-negative group respectively with the difference being very significant between them （P〈0.001）. It was concluded that AQP1 was overexpressed in the HIFl-positive group and there were some correlations between AQP1 and HIF1, suggesting they interact each other and regulate the oncogenesis of breast cancer.

Effects of hypoxia-inducible factor 1 on ischemic cerebrovascular disease

Hypoxia-inducible factor 1, a nuclear transcription factor, is induced by hypoxia. Hypoxia-inducible factor 1, a heterodimeric DNA-binding protein, is composed of hypoxia-inducible factor 1α and hypoxia-inducible factor 1βsubunits, which are family members of the basic helix-loop-helix-PER, ARNT, SIM （PAS） protein. O2 concentration regulates hypoxia-inducible factor 1 activity via this subunit. Hypoxia-inducible factor 1α plays a major role in response to hypoxia and transcriptional activation, as well as in the target gene specificity of the DNA enhancer. Hypoxia-inducible factor 1β cannot be induced by hypoxia. This effect may be due to hypoxia-inducible factor 1 stability and activated conformation due to dimerization. Previous studies have shown that hypoxia-inducible factor 1 mRNA expression increases in the penumbra following ischemia/hypoxia. Hypoxia-inducible factor 1 plays an important role in brain tissue injury after ischemia by affecting a series of target genes, elevating tolerance to hypoxia, and ensuring survival of neural cells. This article summarizes the structure, function, expression, regulatory mechanisms, biological effects, and significance of hypoxia-inducible factor 1 in patients with ischemic cerebrovascular disease. As a transcriptional activator, hypoxia- inducible factor 1 plays a key role in hypoxic responses by stabilizing the internal environment. It also has been shown to regulate the expression of several genes. The regulatory effects of hypoxia-inducible factor 1 in patients with ischemic cerebrovascular disease have been described. The present review re-examined the concept of brain protection at the level of gene regulation.