Hypoxia activates the hypoxia-inducible factor-1α/vascular endothelial growth factor pathway in a prostatic stromal cell line:A mechanism for the pathogenesis of benign prostatic hyperplasia

Background The development of benign prostatic hyperplasia(BPH)is closely related to hypoxia in the prostatic stroma,and the hypoxia-inducible factor-1α/vascular endothelial growth factor(HIF-1α/VEGF)pathway has been shown to significantly activate in response to hypoxia.The underlying mechanism for activation of this pathway in the pathogenesis of BPH remains unclear.Materials and methods We constructed HIF-1αoverexpression and knockdown BPH stromal(WPMY-1)and epithelial(BPH-1)cell lines,which were cultured under different oxygen conditions(hypoxia,normoxia,and hypoxia+HIF-1αinhibitor).Quantitative real-time polymerase chain reaction(qPCR)and Western blotting were applied to detect the expression of the HIF-1α/VEGF pathway.Cell proliferation and apoptosis were analyzed by Cell Counting Kit-8 and flow cytometry.We used the miRWalk 2.0 database and Western blotting to predict the potential miRNA that selectively targets the HIF-1α/VEGF pathway,and verified the prediction by qPCR and dual-luciferase assays.Results In a BPH stromal cell line(WPMY-1),the expression of VEGF was in accordance with HIF-1αlevels,elevated in the overexpression cells and decreased in the knockdown cells.Hypoxia-induced HIF-1αoverexpression,which could be reversed by a HIF-1αinhibitor.Moreover,the HIF-1αinhibitor significantly depressed cellular proliferation and promoted apoptosis in hypoxic conditions,assessed by Cell Counting Kit-8 and flow cytometry.However,in the BPH epithelial cell line(BPH-1),the expression level of HIF-1αdid not influence the expression of VEGF.Finally,a potential miRNA,miR-17-5p,regulating the HIF-1α/VEGF pathway was predicted from the miRWalk 2.0 database and Western blotting,and verified by qPCR and dual-luciferase assay.Conclusions In hypoxia,activation of the HIF-1α/VEGF pathway plays a crucial role in regulating cell proliferation in a BPH stromal cell line.Regulation by miR-17-5p may be the potential mechanism for the activation of this pathway.Regulation of this pathway may be involved in the pathogenesis of BPH.

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.

Transforming growth factor-β1 and vascular endothelial growth factor levels in senile acute myeloid leukemia and correlation with prognosis

BACKGROUND Acute myeloid leukemia(AML)is a disease in which immature hematopoietic cells accumulate in the bone marrow and continuously expand,inhibiting hematopoiesis.The treatment and prognosis of this disease have always been unsatisfactory.AIM To investigate the correlation between vascular endothelial growth factor(VEGF)and transforming growth factor-β1(TGFβ1)expression and prognosis in older adults with AML.METHODS This study enrolled 80 patients with AML(AML group),including 36 with complete response(AML-CR),23 with partial response(AML-PR),and 21 with no response(AML-NR).The expression levels of VEGF and TGFβ1 were detected by reverse transcription polymerase chain reaction in bone marrow mononuclear cells isolated from 56 healthy controls.Kaplan-Meier analysis was performed to assess overall survival(OS)and progression-or disease-free survival(DFS).Prognostic risk factors were analyzed using a Cox proportional hazards model.RESULTS The AML group showed a VEGF level of 2.68±0.16.VEGF expression was lower in patients with AML-CR than those with AML-PR or AML-NR(P<0.05).TGFβ1 expression in the AML group was 0.33±0.05.Patients with AML-CR showed a higher TGFβ1 expression than those with AML-PR or AML-NR(P<0.05).VEGF and TGFβ1 expression in patients with AML was significantly correlated with the counts of leukocytes,platelets,hemoglobin,and peripheral blood immature cells(P<0.05);Kaplan-Meier survival analysis revealed that patients with high TGFβ1 expression had better OS and DFS than those with low TGFβ1 expression(P<0.05),whereas patients with low VEGF levels showed better OS and DFS than those with high VEGF levels(P<0.05).VEGF,TGFβ1,and platelet count were identified by the Cox proportional hazards model as independent risk factors for OS(P<0.05),while VEGF,TGFβ1,and white blood cell count were independent risk factors for DFS(P<0.05).CONCLUSION Decreased VEGF expression and increased TGFβ1 expression in patients with AML provide valuable references for determining and individualizing clinical treatment strategies.

Phosphatase and tensin homology deleted in chromosome 10,hypoxia-inducible factor-1 alpha gene expression in colorectal adenoma and adenocarcinoma and their relation to vascular endothelial growth factor protein expression

To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.

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.

Expression of hypoxia-inducible factor la and vascular endothelial growth factor in hepatocellular carcinoma: Impact on neovascularization and survival

AIM: To study the expression of hypoxia-inducible factor 1α(HIF-1α) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and the impact on neovascularization and survival. METHODS: Expressions of HIF-1α, VEGF and microvessel density (MVD) are studied through immunohistochemistry in 36 cases of HCC and the corresponding paraneoplastic tissue and 6 cases of normal liver tissue. The relationship of the expressions of HIF-1α and VEGF with the clinicopathological data and survival are analyzed. RESULTS: The positive rate of VEGF in HCC was 32/36, which is significantly higher than that in paraneoplastic tissue and normal liver tissue (P<0.05). The expression of HIF-1aaaaaa in HCC tissue is 24/36, also higher than that in paraneoplastic tissue and normal liver tissue (P<0.05). The expression of VEGF and HIF-1α in HCC with microscopic venous invasion is significantly higher than that in HCC without microscopic venous invasion (P<0.05). Spearman correlation analysis does not only show the expression of HIF-1α as correlated with the expression of VEGF (rs = 0.459, P<0.01), but it also shows the expression of HIF-1α and VEGF as correlated with MVD (rs=0.412 and 0.336, respectively, P<0.05). The differences of the survival rates among VEGF positive group and VEGF negative group are significant (P<0.05), whereas the differences of the survival rates among the HIF-1α negative group and positive group are not significant (P>0.05). CONCLUSION: HIF-1α plays important roles in neovascularization in HCC possibly through regulation of VEGF transcription.

Vascular endothelial growth factor A, secreted in response to transforming growth factor-β1 under hypoxic conditions, induces autocrine effects on migration of prostate cancer cells

Hypoxia and transforming growth factor-β1 （TGF-β1） increase vascular endothelial growth factor A （VEGFA） expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines （HPV7 and RWPE1） and prostate cancer cell lines （DU 145 and PC3）. Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor （ALK5） kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor （VEGFR） 1 （Fit-l） and 2 （FIk-I/KDR）. Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERKI/2） in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.

The Effect of Simvastatin on mRNA Expression of Transforming Growth Factor-β1,Bone Morphogenetic Protein-2 and Vascular Endothelial Growth Factor in Tooth Extraction Socket

Aim To determine the effect of local simvastatin application on the mRNA expression level of transforming growth factor-β1 （TGF-β1）, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） in the tooth sockets of rat. Methodology Forty-eight male Wistar rats were randomly divided into experimental and control groups （n=24）. Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The expression of TGF-β1, BMP-2 and VEGF mRNA was determined by in situ hybridization in the tooth extraction socket at five days, one week, two weeks and four weeks after implantation. Results The fusiform stroma cells in the tooth extraction socket began to express TGF-β1, BMP-2 and VEGF mRNA in both experimental and control groups from one week after tooth extraction until the end of experiment. The expression of TGF-131 and BMP-2 mRNA in the experimental group was significantly up-regulated after one, two and four weeks, and expression of VEGF mRNA was significantly increased after one and two weeks compared with that in the control group. Conclusion The findings indicate that local administration of simvastatin can influence alveolar bone remodeling by regulating the expression of a school of growth factors which are crucial to osteogenesis in the tooth extraction socket.

Elevated levels of interleukin-1β, interleukin-6, tumor necrosis factor-α and vascular endothelial growth factor in patients with knee articular cartilage injury

BACKGROUND Inflammatory cytokines play a vital role in the occurrence of osteoarticular injury and inflammation. Whether inflammation-associated factors interleukin-1β(IL- 1β), IL-6, tumor necrosis factor-α(TNF-α) and vascular endothelial growth factor (VEGF) are involved in the pathogenesis of keen articular cartilage injury remains poorly understood. AIM To measure the levels of inflammatory factors [IL-1β, IL-6, TNF-α and VEGF] in patients with knee articular cartilage injury. METHODS Fifty-five patients with knee articular cartilage injury were selected as patient groups, who were divided into three grades [mild (n = 20), moderate (n = 19) and severe (n = 16)] according to disease severity and X-ray examinations. Meanwhile, 30 healthy individuals who underwent physical examination were selected as the control group. The levels of IL-1β, IL-6, TNF-α and VEGF were measured by ELISA and immunohistochemical staining. RESULTS Compared with the control group, patient groups displayed significantly higher levels of IL-1β, IL-6, TNF-α and VEGF, and the extent of increase was directly proportional to the severity of injury (P < 0.05). In addition, the number of cells with positive staining of IL-1β, IL-6, TNF-α and VEGF in the synovial membrane were significantly increased, along with increased disease severity (P < 0.05). After treatment, the scores of visual analogue scale and the Western Ontario and McMaster University of Orthopaedic Index in patient groups were 2.26 ± 1.13 and 15.56 ± 7.12 points, respectively, which were significantly lower than those before treatment (6.98 ± 1.32 and 49.48 ± 8.96). Correlation analysis suggested that IL-1β and TNF-α were positively correlated with VEGF. CONCLUSION IL-1β, IL-6, TNF-α and VEGF levels are increased in patients with knee articular cartilage injury, and are associated with the disease severity, indicating they might play an important role in the occurrence and development of knee articular cartilage injury. Furthermore, therapeutically targeting them might be a novel approach for the treatment of keen articular cartilage injury.

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.

Apelin and vascular endothelial growth factor are associated with mobilization of endothelial progenitor cells after acute myocardial infarction

This study was designed to determine the levels of early endothelial progenitor cells （EPCs）, apelin, vascu- lar endothelial growth factor （VEGF） and stromal cell-derived growth factor-1 （SDF-1） after acute myocardial infarction （AMI）, and to investigate the relationships between these cytokines and early EPCs. Early EPCs, de- fined as CD133＋, KDR＋, and CD34~ cells, were quantified by flow cytometry. The levels of early EPCs and those cytokines in AMI patients were significantly different from those with coronary artery disease or controls （P 〈 0.05）. Plasma apelin levels were inversely correlated with Gensini score and early EPCs （both P 〈 0.01）. Early EPCs, VEGF and SDF-1 showed different patterns of changes in AMI patients during the first 24 h. The trend in the change of early EPCs was proportionally correlated with that of VEGF （P 〈 0.05）. AMI patients exhibited in- creased early EPCs with remarkably decreased apelin levels and enhanced VEGF levels.

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.

Expression of Nerve Growth Factor and Hypoxia Inducible Factor-1α and Its Correlation with Angiogenesis in Non-Small Cell Lung Cancer

Summary： In order to investigate the expression of nerve growth factor （NGF） and hypoxia inducible factor-1α （HIF-1α） and its correlation with angiogenesis in non-small cell lung cancer （NSCLC）, paraffin-embedded tissue blocks from 20 patients with NSCLC were examined. Twenty corresponding para-cancerous lung tissue specimens were obtained to serve as a control. The expression of NGF, HIF-1α, and vascular endothelial growth factor （VEGF） in the NSCLC tissues was detected by using immunohistochemistry. The microvascular density （MVD） was determined by CD31 staining. The resuits showed that the expression levels ofNGF, HIF-1α and VEGF in the NSCLC tissues were remarkably higher than those in the para-cancerous lung tissues （P〈0.05）. There was significant difference in the MVD between the NSCLC tissues （9.19±1.43） and para-cancerous lung tissues （2.23±1.19） （P〈0.05）. There were positive correlations between NGF and VEGF, between HIF-1α and VEGF, and between NGF and HIF-1α in NSCLC tissues, with the spearman correlation coefficient being 0.588, 0.519 and 0.588, respectively. In NSCLC tissues, the MVD had a positive correlation with the three factors （P〈0.05）. Theses results suggest that NGF and HIF-1α are synergically involved in the angiogenesis of NSCLC.

Hypoxia-inducible factor-1 alpha regulates the role of vascular endothelial growth factor on pulmonary arteries of rats with hypoxia-induced pulmonary hypertension

Background Hypoxia-inducible factor-1α (HIF-1α) is one of the pivotal mediators in the response of lungs to decreased oxygen availability, and increasingly has been implicated in the pathogenesis of pulmonary hypertension. Vascular endothelial growth factor (VEGF), a downstream target gene of HIF-1α, plays an important role in the pathogenesis of hypoxic pulmonary hypertension and hypoxic pulmonary artery remodelling. In this study, we investigated the dynamic expression of HIF-1α and VEGF in pulmonary artery of rats with hypoxia-induced pulmonary hypertension. Methods Forty male Wistar rats were exposed to hypoxia for 0, 3, 7, 14 or 21 days. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricle hypertrophy index (RVHI) were estimated. Lungs were inflated and fixed for in situ hybridisation and immunohistochemistry. Results mPAP values were significantly higher than the control values after 7days of hypoxia [(18.4±0.4) mmHg, P<0.05]. RVHI developed significantly after 14 days of hypoxia. Expression of HIF-1α protein increased in pulmonary arterial tunica intima of all hypoxic rats. In pulmonary arterial tunica media, HIF-1α protein was markedly increased by day 3 (0.20±0.02, P<0.05), reached the peak by day 7, then declined after day 14 of hypoxia. HIF-1α mRNA increased significantly after day 14 of hypoxia (0.20±0.02, P<0.05). VEGF protein began to increase markedly after day 7 of hypoxia, reaching its peak around day 14 of hypoxia (0.15±0.02, P<0.05). VEGF mRNA began to increase after day 7 of hypoxia, then remained more or less stable from day 7 onwards. VEGF mRNA is located mainly in tunica intima and tunica media, whereas VEGF protein is located predominantly in tunica intima. Linear analysis showed that HIF-1α mRNA, VEGF and mPAP were correlated with hypoxic pulmonary artery remodelling. HIF-1α mRNA was positively correlated with VEGF mRNA and protein (P<0.01). Conclusion HIF-1α and VEGF are both involved in the pathogenesis of hypoxia-induced pulmonary hypertension in rats.

Hyperbaric oxygen intervention on expression of hypoxia-inducible factor-1 α and vascular endothelial growth factor in spinal cord injury models in rats

Background Hyperbaric oxygen （HBO） intervention is a main therapeutic method and the curative effect has been certified for spinal cord injury （SCI）, but the mechanisms of the neuroprotective effect of HBO on SCI remain elusive. This study aimed to observe the change in expression of hypoxia-inducible factor-1α （HIF-1α） and vascular endothelial growth factor （VEGF） after SCI at different time points and to investigate the neuroprotective mechanism of HBO on SCI in rats.

Tongxinluo Inhibits Cyclooxygenase-2, Inducible Nitric Oxide Synthase, Hypoxia-inducible Factor-2α/Vascular Endothelial Growth Factor to Antagonize Injury in Hypoxia-stimulated Cardiac Microvascular Endothelial Cells

Background： Endothelial dysflinction is considered as the initiating process and pathological basis of cardiovascnlar disease. Cyclooxygenase-2 （COX-2） and prostacyclin synthase （PGIS）, inducible nitric oxide synthase （iNOS） and endothelial NOS （eNOS） are key enzymes with opposing actions in inflammation and oxidative stress, which are believed to be the major driver of endothelial dysfunction. And in hypoxia （Hx）, Hx-inducible factor （HIF）-1α and HIF-2α are predominantly induced to activate vascular endothelial growth factor （VEGF）, restllting in abnormal proliferation. Whether and how Tongxinluo （TXL） modulates COX-2, PGIS, iNOS, eNOS, HIF-1α, HIF-2α, and VEGF in Hx-stimulated human cardiac microvascular endothelial cells （HCM ECs） have not been clarified. Methods： HCMEC were treated with CoCl2 to mimic Hx and the mRNA expressions of COX-2, PGIS, iNOS, eNOS, HIF-1α, HIF-2α. and VEGF were first confirmed, and then their mRNA expression and protein content as well as the cell pathological alterations were evaluated for TXL treatment with different concentrations, In addition, the effector molecular of inflammation prostaglandin E2 （PGE2） and the oxidative marker nitrotyrosine （NT） was adopted to reflect HCMEC in.jury. Results： Hx could induce time-dependent increase of COX-2, iNOS, HIF-2α, and VEGF in HCMEC. Based on the Hx-induced increase, TXL could mainly decrease COX-2, iNOS, HIF-2α, and VEGF in a concentration-dependent manner, with limited effect on the increase of PGIS and eNOS. Their protein contents verified the mRNA expression changes, which was consistent with the cell morphological alterations. Furthermore, high dose TXL could inhibit the Hx-induced increase of PG E, and NT contents, attenuating the inflammatory and oxidative injury. Conclusions： TXL could inhibit inflammation-related COX-2, oxidative stress-related iNOS, and H IF-2α/VEGF to antagonize Hx-induced HCMEC injury.

Effect of acetyl L-carnitine on human retinal pigment epithelium-19 cells in hypoxic conditions

AIM:To investigate the effect of acetyl-L-carnitine(ALCAR)on cell viability,morphological integrity,and vascular endothelial growth factor(VEGF)expression in human retinal pigment epithelium(ARPE-19)cells using a hypoxic model.METHODS:In the first set of experiments,the optimal CoCl_(2) dose was determined by exposing ARPE-19 cell cultures to different concentrations.To evaluate the effect of ALCAR on cell viability,five groups of ARPE-19 cell culture were established that included a control group,a sham group(200μM CoCl_(2)),and groups that received 1,10 and 100 mM doses of ALCAR combined with 200μM CoCl_(2),respectively.The cell viability was measured by MTT assay.The morphological characteristics of cells were observed by an inverted phase contrast microscope.The levels of VEGF and HIF-1α secretion by ARPE-19 cells were detected by enzyme linked immunosorbent assay(ELISA)assay.RESULTS:ARPE-19 cells were exposed to different doses of CoCl_(2) in order to create a hypoxia model.Nevertheless,when exposed to a concentration of 200μM CoCl_(2),a notable decrease in viability to 83% was noted.ALCAR was found to increase the cell viability at 1 mM and 10 mM concentrations,while the highest concentration(100 mM)did not have an added effect.The cell viability was found to be significantly higher in the groups treated with a concentration of 1 mM and 10 mM ALCAR compared to the Sham group(P=0.041,P=0.019,respectively).The cell viability and morphology remained unaffected by the greatest dose of ALCAR(100 mM).The administration of 10 mM ALCAR demonstrated a statistically significant reduction in the levels of VEGF and HIF-1α compared with the Sham group(P=0.013,P=0.033,respectively).CONCLUSION:The findings from the current study indicate that ALCAR could represent a viable therapeutic option with the potential to open up novel treatment pathways for retinal diseases,particular relevance for age-related macular degeneration(AMD).However,to fully elucidate ALCAR’s application potential in retinal diseases,additional investigation is necessary to clearly define the exact mechanisms involved.

Lichong decoction inhibits micro-angiogenesis by reducing the expressions of hypoxia inducible factor-1αand vascular endothelial growth factor in hysteromyoma mouse model

OBJECTIVE:To investigate the efficacy of Lichong decoction(LD)from Traditional Chinese Medicine,on micro-angiogenesis in a mouse model of hysteromyoma.METHODS:A mouse model of hysteromyoma was developed by orthotopic intrauterine injection of primary human myoma cells isolated from patients from the Beijing Obstetrics and Gynecology Hospital into CB-17 Scid mice.Mice were administered high-dose LD,low-dose LD,mifepristone or water(control)daily by gavage for 4 weeks.Uterine diameter and coefficient(uterine weight/body weight)were measured.Uterine morphology was assessed by light microscopy(hematoxylin and eosin)and transmission electron microscopy.Serum levels of estradiol,progesterone,follicle-stimulating hormone and luteinizing hormone(LH)were measured by enzyme-linked immunosorbent assay.Uterine protein expression of hypoxia inducible factor(HIF)-1α,CD31 and proliferating cell nuclear antigen(PCNA)was detected by immunohistochemistry.VEGF and HIF-1αm RNAs were quantified by RT-PCR.RESULTS:High-dose LD,low-dose LD and mifepristone reduced uterine diameter and coefficient,and attenuated the morphologic abnormalities associated with hysteromyoma.High-dose LD,low-dose LD and mifepristone inhibited hysteromyoma-induced micro-angiogenesis,as evidenced by a decrease in the number of new microvessels co-immunostaining for CD31 and PCNA(P<0.01).High-dose LD and mifepristone lowered serum levels of estradiol,progesterone and LH(P<0.05).High-dose LD,low-dose LD and mifepristone down-regulated HIF-1αm RNA and protein expressions and VEGF m RNA expression(P<0.01).CONCLUSION:The inhibition of hysteromyoma by LD may involve reductions in HIF-1αand VEGF expression and suppression of micro-angiogenesis.

Expression levels and significance of hypoxia inducible factor-1 alpha and vascular endothelial growth factor in human colorectal adenocarcinoma

Background Hypoxia-inducible factor 1 (HIF-1), a transcription factor, is overexpressed in common human cancers and their metastases. This study aimed at determining the expression levels of HIF-1α and vascular endothelial growth factor (VEGF) in SW480 cells and in colorectal adenocarcinoma tissue and ascertaining whether HIF-1α and VEGF play important roles in tumor angiogenesis. Methods HIF-1α mRNA expression was analyzed using in situ hybridization and RT-PCR. HIF-1α and VEGF protein were detected in SW480 cells and colorectal adenomas and adenocarcinomas by immunohistochemistry using streptavidin/peroxidase (SP). Western blot was used to detect HIF-1α protein extracted from SW480 cells. Microvessel density (MVD) in colorectal carcinomas was determined by anti-CD_ 34 immunostaining in colorectal carcinomas. Results Optical density values representing HIF-1α mRNA expression levels were found to be significantly higher in SW480 cells in hypoxic conditions than in cells under normoxic conditions (P<0.05) or in hypoxic conditions but treated with genistein (P<0.05). The levels of HIF-1α and VEGF protein expression in SW480 cells were significantly higher in the hypoxia group than in the normoxia group (P<0.01, P<0.05, respectively) and hypoxia/genistein group (P<0.01, P<0.05, respectively). The positive expression rates of HIF-1α mRNA changed dramatically when comparing colorectal adenomas with adenocarcinomas of different Dukes’ stages (P<0.05). HIF-1α mRNA was also expressed at higher levels in adenocarcinomas than that in adenomas (P<0.01). HIF-1α protein expression correlated significantly with VEGF protein expression and MVD.Conclusions Hypoxia induces the expression of HIF-1α and VEGF in colorectal adenocarcinomas. HIF-1α may play an important role in angiogenesis and tumor progression by regulating the expression of VEGF in human colorectal carcinomas.

Construction of recombinant adenovirus co-expression vector carrying the human transforming growth factor-β1 and vascular endothelial growth factor genes and its effect on anterior cruciate ligament fibroblasts

Background Remodeling of the anterior cruciate ligament （ACL） graft usually takes longer than expected. Gene therapy offers a radical different approach to remodeling of the graft. In this study, the internal ribosome entry site （IRES） sequence was used to construct a new recombinant adenovirus which permits co-expression of transforming growth factor-β1 （TGFβ1） and vascular endothelial growth factor 165 （VEGF165） genes （named Ad-VEGF165-IRES-TGFβ1）. We investigated the effects of the new adenovirus on the migration of and matrix synthesis by ACL fibroblasts. Methods Adenoviral vector containing TGFβ1 and VEGF165 genes was constructed. ACL fibroblasts were obtained from New Zealand white rabbits. After ACL fibroblasts were exposed to Ad-VEGF165-IRES-TGFβ1, the expression of VEGF165 and TGFβ1 proteins were assessed by enzyme-linked immunosorbent assay （ELISA） and Western blotting analysis. Bioassay of VEGF165 and TGFβ1 proteins were assessed by Western blotting analysis. Proliferation and migration of ACL fibroblasts were assessed by in vitro wound closure assay. Gene expression of collagen type Ⅰ, collagen type Ⅲ, and fibronectin mRNA among matrix markers were assessed by real-time PCR. Results The results showed the successful construction of a recombinant co-expression adenovirus vector containing TGFβ1 and VEGF165 genes. Co-expression of TGFβ1 and VEGF165 can induce relatively rapid and continuous proliferation of ACL fibroblasts and high gene expression of collagen type Ⅰ, collagen type Ⅲ, and fibronectin mRNA among matrix markers. Conclusion Co-expression of TGFβ1 and VEGF165 genes has more powerful and efficient effects on the migration of and matrix synthesis by ACL fibroblasts.