scholarly journals Intrauterine Exposure to Cadmium Reduces HIF-1 DNA-Binding Ability in Rat Fetal Kidneys

Toxics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 53 ◽  
Author(s):  
Tania Jacobo-Estrada ◽  
Mariana Cardenas-Gonzalez ◽  
Mitzi Santoyo-Sánchez ◽  
Frank Thevenod ◽  
Olivier Barbier
Keyword(s):  
Dna Binding ◽  
Kidney Development ◽  
Protein Extraction ◽  
Hypoxia Inducible Factor ◽  
Isotonic Saline ◽  
Mrna Levels ◽  
Vegf Mrna ◽  
Binding Ability ◽  
Protein Levels ◽  
Cd Exposure

During embryonic development, some hypoxia occurs due to incipient vascularization. Under hypoxic conditions, gene expression is mainly controlled by hypoxia-inducible factor 1 (HIF-1). The activity of this transcription factor can be altered by the exposure to a variety of compounds; among them is cadmium (Cd), a nephrotoxic heavy metal capable of crossing the placenta and reaching fetal kidneys. The goal of the study was to determine Cd effects on HIF-1 on embryonic kidneys. Pregnant Wistar rats were exposed to a mist of isotonic saline solution or CdCl2 (DDel = 1.48 mg Cd/kg/day), from gestational day (GD) 8 to 20. Embryonic kidneys were obtained on GD 21 for RNA and protein extraction. Results show that Cd exposure had no effect on HIF-1α and prolyl hydroxylase 2 protein levels, but it reduced HIF-1 DNA-binding ability, which was confirmed by a decrease in vascular endothelial growth factor (VEGF) mRNA levels. In contrast, the protein levels of VEGF were not changed, which suggests the activation of additional regulatory mechanisms of VEGF protein expression to ensure proper kidney development. In conclusion, Cd exposure decreases HIF-1-binding activity, posing a risk on renal fetal development.

Effects of hyperoxia on VEGF, its receptors, and HIF-2α in the newborn rat lung

2003 ◽  
Vol 285 (1) ◽  
pp. L161-L168 ◽  
Author(s):  
Gayle E. Hosford ◽  
David M. Olson
Keyword(s):  
Hypoxia Inducible Factor ◽  
Treated Group ◽  
Receptor Protein ◽  
Vegf Receptor ◽  
Mrna Levels ◽  
Signaling System ◽  
Vegf Mrna ◽  
Receptor System ◽  
Protein Levels ◽  
Vegf Signaling

Signaling through the hypoxia inducible factor (HIF)-VEGF-VEGF receptor system (VEGF signaling system) leads to angiogenesis and epithelial cell proliferation and is a key mechanism regulating alveolarization in lungs of newborn rats. Hyperoxia exposure (>95% O2 days 4–14) arrests lung alveolarization and may do so through suppression of the VEGF signaling system. Lung tissue mRNA levels of HIF-2α and VEGF increased from days 4–14 in normoxic animals, but hyperoxia suppressed these increases. Levels of HIF-2α and VEGF mRNA were correlated in the air but not the O2-treated group, suggesting that the low levels of HIF-2α observed at high O2 concentrations are not stimulating VEGF expression. VEGF164 protein levels increased with developmental age, and with hyperoxia to day 9, but continuing hyperoxia decreased levels by day 12. VEGFR1 and VEGFR2 mRNA expression also increased in air-exposed animals, and these, too, were significantly decreased by hyperoxia by day 9 and day 12, respectively. Receptor protein levels did not increase with development; however, O2 did decrease protein to less than air values. Hyperoxic suppression of VEGF signaling from days 9–14 may be one mechanism by which alveolarization is arrested.

Cytokines induce HIF-1 DNA binding and the expression of HIF-1-dependent genes in cultured rat enterocytes

2003 ◽  
Vol 284 (3) ◽  
pp. G373-G384 ◽  
Author(s):  
Marion Scharte ◽  
Xiaonan Han ◽  
Daniel J. Bertges ◽  
Mitchell P. Fink ◽  
Russell L. Delude
Keyword(s):  
Dna Binding ◽  
Epithelial Cells ◽  
Hypoxia Inducible Factor ◽  
Adaptation To Hypoxia ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Vegf Mrna ◽  
Hypoxic Conditions ◽  
Steady State Levels ◽  
Aldolase A

Cellular adaptation to hypoxia depends, in part, on the transcription factor hypoxia-inducible factor-1 (HIF-1). Normoxic cells exposed to an inflammatory milieu often manifest phenotypic changes, such as increased glycolysis, that are reminiscent of those observed in hypoxic cells. Accordingly, we investigated the effects of cytomix, a mixture containing IFN-γ, TNF, and IL-1β on the expression of HIF-1-dependent proteins under normoxic and hypoxic conditions. Incubation of intestine-derived epithelial cells (IEC-6) under 1% O2increased HIF-1 DNA binding and expression of aldolase A, enolase-1, and VEGF mRNA. Incubation of normoxic cells with cytomix for 48 h also markedly increased HIF-1 DNA binding and expression of mRNAs for these proteins. Incubation of hypoxic cells with cytomix did not inhibit HIF-1 DNA binding or upregulation of HIF-1-dependent genes in response to hypoxia. Neither cytomix nor hypoxia increased steady-state levels of HIF-1α mRNA. Incubation of IEC-6 cells with cytomix induced nitric oxide (NO·) biosynthesis, which was blocked if the cultures containedl- NG-(1-iminoethyl)lysine hydrochloride (l-NIL). Treatment with l-NIL, however, failed to significantly alter aldolase A, enolase-1, and VEGF mRNA levels in normoxic cytomix-treated cells. Proinflammatory cytokines activate the HIF-1 pathway and increase expression of glycolytic genes in nontransformed rat intestinal epithelial cells, largely through an NO·-independent mechanism.

scholarly journals Inhibitor of DNA Binding 1 Is Induced during Kidney Ischemia-Reperfusion and Is Critical for the Induction of Hypoxia-Inducible Factor-1α

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Dan Wen ◽  
Yan-Fang Zou ◽  
Yao-Hui Gao ◽  
Qian Zhao ◽  
Yin-Yin Xie ◽  
...  
Keyword(s):  
Dna Binding ◽  
Ischemia Reperfusion ◽  
Hypoxia Inducible Factor ◽  
Kidney Injury ◽  
Mrna Levels ◽  
Hypoxia Inducible Factor 1 ◽  
Renal Tubular ◽  
Inhibitor Of Dna Binding

In this study, rat models of acute kidney injury (AKI) induced by renal ischemia-reperfusion (I/R) and HK-2 cell models of hypoxia-reoxygenation (H/R) were established to investigate the expression of inhibitor of DNA binding 1 (ID1) in AKI, and the regulation relationship between ID1 and hypoxia-inducible factor 1 alpha (HIF-1α). Through western blot, quantitative real-time PCR, immunohistochemistry, and other experiment methods, the induction of ID1 after renal I/R in vivo was observed, which was expressed mainly in renal tubular epithelial cells (TECs). ID1 expression was upregulated in in vitro H/R models at both the protein and mRNA levels. Via RNAi, it was found that ID1 induction was inhibited with silencing of HIF-1α. Moreover, the suppression of ID1 mRNA expression could lead to decreased expression and transcription of HIF-1αduring hypoxia and reoxygenation. In addition, it was demonstrated that both ID1 and HIF-1αcan regulate the transcription of twist. This study demonstrated that ID1 is induced in renal TECs during I/R and can regulate the transcription and expression of HIF-1α.

Hypoxia Inducible Factor-1α Is over Expressed in CLL B Cells Because of an Impaired Proteasome Pathway Associated with Defective Interaction with von Hippel-Landau Protein.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2115-2115 ◽  
Author(s):  
Yean K. Lee ◽  
Ann K. Strege ◽  
Nancy D. Bone ◽  
Linda E. Wellik ◽  
D. A. Chan ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Nuclear Extract ◽  
Degradation Pathway ◽  
Mrna Levels ◽  
Apoptosis Resistance ◽  
Vegf Mrna ◽  
Prolyl Hydroxylases

Abstract We have found that CLL B cells spontaneously secrete vascular endothelial growth factor (VEGF) and that a VEGF autocrine pathway can induce apoptosis resistance in these cells. Recently, we also found that hypoxia-inducible factor-1 alpha (HIF-1α) is highly expressed in CLL B cells. Since this protein is a potent transcription factor for the induction of VEGF, we were interested in further definition of HIF-1α regulation and its function in CLL B cells. CLL blood B cells overexpress HIF-1α protein but not mRNA for HIF-1α compared to normal blood and splenic B cells. Immunohistochemistry (IHC) showed that circulating blood CLL B cells and a subset of CLL marrow cells uniformly express HIF. Hypoxic conditions (i.e., 1% O2) did not increase the protein levels of HIF-1α nor mRNA for HIF-1α in CLL B cells, indicating that the high HIF-1α protein level is due to post-translation modification. Blockade of signaling pathways known to increase HIF-1α levels also did not alter the high levels of HIF-1α in CLL B cells. IHC and nuclear extraction assay demonstrated that HIF-1α was predominantly located in the CLL B cell nucleus. In addition, the nuclear extract when immunoprecipitated for HIF-1α was shown to be complexed with the co-activator p300, indicating that HIF-1α is transcriptionally active. Co-immunoprecipitation assay showed that HIF-1α from CLL B cells does not associate and form a complex with von Hippel-Landau protein tumor suppressor (pVHL), indicating that the proteasome dependent degradation pathway for HIF-1α protein in CLL B cells is dysfunctional. Using immunoblot or IHC methods, we were unable to detect pVHL protein in CLL B cells; however, we were able to use immunoprecipitation of CLL B cell lysates to demonstrate there is pVHL in CLL B cells. Prolyl hydroxylases (PHD 1, 2, and 3) are negative regulators for HIF-1α via hydroxylation of amino acid prolines in the oxygen degradation domain (ODD) which permits interaction with pVHL. RT-PCR results revealed that there is a subset of CLL patients who had ≥ 50% reduction of PHD 1 and 3 mRNA levels. However using a hydroxylation specific polyclonal antibody we found that HIF-1α from CLL B cells is indeed hydroxylated. Finally, silencing of HIF-1α by RNA interference in CLL B cells was associated with a selective decrease in VEGF mRNA levels but not VEGF-R1, Mcl-1 and prolyl hydroxylases (PHD 1–3) other downstream target genes of HIF-1α. These data show that the high endogenous HIF-1α levels in CLL B cells are due to a defect in HIF-1α degradation via the proteosomal pathway. We believe that this abnormality is linked to the autocrine VEGF pathway in CLL B cells and ultimately results in increases in their apoptotic resistance. Inhibition of HIF-1α levels may be of therapeutic benefit to CLL patients.

scholarly journals Stathmin, a Microtubule Regulatory Protein, Is Associated with Hypoxia-Inducible Factor-1α Levels in Human Endometrial and Endothelial Cells

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2413-2418 ◽  
Author(s):  
Mikihiro Yoshie ◽  
Eri Miyajima ◽  
Satoru Kyo ◽  
Kazuhiro Tamura
Keyword(s):  
Endothelial Cells ◽  
Menstrual Cycle ◽  
Regulatory Protein ◽  
Hypoxia Inducible Factor ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Endometrial Cells ◽  
Protein Levels

Local hypoxia that occurs during menstruation triggers angiogenesis that is crucial for cyclical remodeling of the endometrium during the menstrual cycle. Hypoxia is thought to be important for the expression of vascular endothelial growth factor (VEGF) via its transcriptional factor, hypoxia inducible factor (HIF)-1α, in the endometrium. The activation of the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway may modulate HIF-1α protein levels. Stathmin, a microtubule regulatory protein, was expressed in the stroma, glandular epithelium, and vascular endothelium in human endometrium. In this study, we examined a possible role of stathmin in hypoxia-induced HIF-1α and VEGF expression in primary isolated and immortalized human endometrial stromal cells, glandular epithelial cells, and human umbilical venous endothelial cells (HUVEC). Knocking down stathmin expression using small interfering RNA caused microtubule stabilization and inhibited hypoxia-induced VEGF mRNA expression via the reduction of HIF-1α protein levels in endometrial cells and HUVEC. Treatment of the cells with a PI3K inhibitor, wortmannin, inhibited the expression of VEGF mRNA and the accumulation of HIF-1α protein. Silencing of stathmin expression repressed the activation (phosphorylation) of Akt in endometrial cells and HUVEC. These results suggest that endometrial stathmin is linked to HIF-1α protein accumulation and VEGF expression through the PI3K/Akt signaling pathway and may be involved in regeneration of the endometrium during the menstrual cycle in human uterine cells.

scholarly journals Oxygen regulation of the epithelial Na channel in the collecting duct

2011 ◽  
Vol 300 (2) ◽  
pp. F412-F424 ◽  
Author(s):  
Russell F. Husted ◽  
Hongyan Lu ◽  
Rita D. Sigmund ◽  
John B. Stokes
Keyword(s):  
Kinase Activity ◽  
Collecting Duct ◽  
Hypoxia Inducible Factor ◽  
Na Channel ◽  
Mrna Levels ◽  
Apical Surface ◽  
Amp Kinase ◽  
Na Transport ◽  
Protein Levels ◽  
Epithelial Na Channel

The Po2 within the kidney changes dramatically from cortex to medulla. The present experiments examined the effect of changing Po2 on epithelial Na channel (ENaC)-mediated Na transport in the collecting duct using the mpkCCD-c14 cell line. Decreasing ambient O2 concentration from 20 to 8% decreased ENaC activity by 40%; increasing O2 content to 40% increased ENaC activity by 50%. The O2 effect required several hours to develop and was not mimicked by the acid pH that developed in monolayers incubated in low-O2 medium. Corticosteroids increased ENaC activity at each O2 concentration; there was no interaction. The pathways for O2 and steroid regulation of ENaC are different since O2 did not substantially affect Sgk1, α-ENaC, Gilz, or Usp2–45 mRNA levels, genes involved in steroid-mediated ENaC regulation. The regulation of ENaC activity by these levels of O2 appears not to be mediated by changes in hypoxia-inducible factor-1α or -2α activity or a change in AMP kinase activity. Changes in O2 concentration had minimal effect on α- or γ-ENaC mRNA and protein levels; there were moderate effects on β-ENaC levels. However, 40% O2 induced substantially greater total β- and γ-ENaC on the apical surface compared with 8% O2; both subunits demonstrated a greater increase in the mature forms. The α-ENaC subunit was difficult to detect on the apical surface, perhaps because our antibodies do not recognize the major mature form. These results identify a mechanism of ENaC regulation that may be important in different regions of the kidney and in responses to changes in dietary NaCl.

scholarly journals Electroacupuncture on ST36 and GB39 Acupoints Inhibits Synovial Angiogenesis via Downregulating HIF-1α/VEGF Expression in a Rat Model of Adjuvant Arthritis

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Zhu ◽  
Chengguo Su ◽  
Yuzhou Chen ◽  
Xinyu Hao ◽  
Jianzhen Jiang
Keyword(s):  
Synovial Tissue ◽  
Rat Model ◽  
Adjuvant Arthritis ◽  
Hypoxia Inducible Factor ◽  
Sprague Dawley ◽  
Vegf Expression ◽  
Vegf Mrna ◽  
Real Time Quantitative Pcr ◽  
Protein Levels ◽  
Cd34 Expression

Introduction. The hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) play a key role in synovial angiogenesis in rheumatoid arthritis (RA). Therefore, this study aimed to test the hypothesis that electroacupuncture (EA) may inhibit RA synovial angiogenesis via HIF-1α/VEGF expression. Methods. Sprague-Dawley rats were randomly distributed to 4 groups: control, adjuvant arthritis (AA), AA+electroacupuncture (AA+EA), and AA+sham EA groups. AA model was induced by injection of Freund's complete adjuvant in bilateral hind footpad. 3 days after injection, EA was delivered to the acupoints Zusanli (ST 36) and Xuanzhong (GB 39) once every two days for a total of 8 times in the AA+EA group, while sham EA treatment was applied in the AA+sham EA group. The arthritis score, paw volume, and H&E staining for each animal were measured. CD34 expression in synovial tissue of ankle joint was observed by immunohistochemistry. HIF-1α and VEGF mRNA and protein levels in synovial tissue were determined by real-time quantitative PCR and Western blot, respectively. Results. Compared with rats in AA group, EA stimulation significantly decreased arthritis scores, paw volume, and pathological damage of synovial tissues. Moreover, EA markedly suppressed the synovial angiogenesis of AA rats, as evidenced by reduced CD34 positive expression. Furthermore, EA significantly reduced HIF-1α and VEGF mRNA and protein levels in synovial of AA rats. Finally, the CD34 expression in synovial tissue was positively correlated with HIF-1α and VEGF protein levels. Conclusion. EA on ST36 and GB39 acupoints can effectively inhibit synovial angiogenesis in the AA rat model via downregulating HIF-1α/VEGF expression.

scholarly journals SDHC Promoter Methylation, a Novel Pathogenic Mechanism in Parasympathetic Paragangliomas

2017 ◽  
Vol 103 (1) ◽  
pp. 295-305 ◽  
Author(s):  
Cristóbal Bernardo-Castiñeira ◽  
Nuria Valdés ◽  
Marta I Sierra ◽  
Inés Sáenz-de-Santa-María ◽  
Gustavo F Bayón ◽  
...  
Keyword(s):  
Copy Number ◽  
Messenger Rna ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Cluster Assembly ◽  
Iron Sulfur Cluster ◽  
Genetic Event ◽  
Protein Levels ◽  
First Case ◽  
Vhl Protein

Abstract Context Germline mutations in the succinate dehydrogenase A, B, C, and D genes (collectively, SDHx) predispose to the development of paragangliomas (PGLs) arising at the parasympathetic or sympathetic neuroendocrine systems. SDHx mutations cause absence of tumoral immunostaining for SDHB. However, negative SDHB immunostaining has also been found in a subset of PGLs that lack SDHx mutations. Settings Here, we report the comprehensive molecular characterization of one such a tumor of parasympathetic origin compared with healthy paraganglia and other PGLs with or without SDHx mutations. Results Integration of multiplatform data revealed somatic SDHC methylation and loss of the 1q23.3 region containing the SDHC gene. This correlated with decreased SDHC messenger RNA (mRNA) and protein levels. Furthermore, another genetic event found affected the VHL gene, which showed a decreased DNA copy number, associated with low VHL mRNA levels, and an absence of VHL protein detected by immunohistochemistry. In addition, the tumor displayed a pseudohypoxic phenotype consisting in overexpression of the hypoxia-inducible factor (HIF)-1α and miR-210, as well as downregulation of the iron-sulfur cluster assembly enzyme (ISCU) involved in SDHB maturation. This profile resembles that of SDHx- or VHL-mutated PGLs but not of PGLs with decreased VHL copy number, pointing to SDHC rather than VHL as the pathogenic driver. Conclusions Collectively, these findings demonstrate the potential importance of both the SDHC epigenomic event and the activation of the HIF-1α/miR-210/ISCU axis in the pathogenesis of SDHx wild-type/SDHB-negative PGLs. To our knowledge, this is the first case of a sporadic parasympathetic PGL that carries silencing of SDHC, fulfilling the two-hit Knudson’s model for tumorigenesis.

scholarly journals Inhibitory Effect of the Noncamptothecin Topoisomerase I Inhibitor LMP-400 on Female Mice Models and Human Pheochromocytoma Cells

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4094-4104 ◽  
Author(s):  
Jan Schovanek ◽  
Petra Bullova ◽  
Yasin Tayem ◽  
Alessio Giubellino ◽  
Robert Wesley ◽  
...  
Keyword(s):  
Topoisomerase I ◽  
Hypoxia Inducible Factor ◽  
Human Tumor ◽  
Inhibitory Effect ◽  
Mrna Levels ◽  
Topoisomerase I Inhibitor ◽  
Female Mice ◽  
Topoisomerase 1 ◽  
Protein Levels

Metastatic pheochromocytoma continues to be an incurable disease, and treatment with conventional cytotoxic chemotherapy offers limited efficacy. In the present study, we evaluated a novel topoisomerase I inhibitor, LMP-400, as a potential treatment for this devastating disease. We found a high expression of topoisomerase I in human metastatic pheochromocytoma, providing a basis for the evaluation of a topoisomerase 1 inhibitor as a therapeutic strategy. LMP-400 inhibited the cell growth of established mouse pheochromocytoma cell lines and primary human tumor tissue cultures. In a study performed in athymic female mice, LMP-400 demonstrated a significant inhibitory effect on tumor growth with two drug administration regimens. Furthermore, low doses of LMP-400 decreased the protein levels of hypoxia-inducible factor 1 (HIF-1α), one of a family of factors studied as potential metastatic drivers in these tumors. The HIF-1α decrease resulted in changes in the mRNA levels of HIF-1 transcriptional targets. In vitro, LMP-400 showed an increase in the growth-inhibitory effects in combination with other chemotherapeutic drugs that are currently used for the treatment of pheochromocytoma. We conclude that LMP-400 has promising antitumor activity in preclinical models of metastatic pheochromocytoma and its use should be considered in future clinical trials.

Increased expression of HIF-1α, nNOS, and VEGF in the cerebral cortex of anemic rats

2007 ◽  
Vol 292 (1) ◽  
pp. R403-R414 ◽  
Author(s):  
Anya T. McLaren ◽  
Philip A. Marsden ◽  
C. David Mazer ◽  
Andrew J. Baker ◽  
Duncan J. Stewart ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Hypoxia Inducible Factor ◽  
Hemoglobin Concentration ◽  
Mrna Levels ◽  
Cortical Cells ◽  
Neuronal Marker ◽  
Protein Levels ◽  
Axonal Projections ◽  
Endothelial Growth Factor ◽  
Vegf Protein

This study tested the hypothesis that specific hypoxic molecules, including hypoxia-inducible factor-1α (HIF-1α), neuronal nitric oxide synthase (nNOS), and vascular endothelial growth factor (VEGF), are upregulated within the cerebral cortex of acutely anemic rats. Isoflurane-anesthetized rats underwent acute hemodilution by exchanging 50% of their blood volume with pentastarch. Following hemodilution, mean arterial pressure and arterial PaO2 values did not differ between control and anemic rats while the hemoglobin concentration decreased to 57 ± 2 g/l. In anemic rats, cerebral cortical HIF-1α protein levels were increased, relative to controls (1.7 ± 0.5-fold, P < 0.05). This increase was associated with an increase in mRNA levels for VEGF, erythropoietin, CXCR4, iNOS, and nNOS ( P < 0.05 for all), but not endothelial NOS. Cerebral cortical nNOS and VEGF protein levels were increased in anemic rats, relative to controls (2.0 ± 0.2- and 1.5 ± 0.4-fold, respectively, P < 0.05 for both). Immunohistochemistry demonstrated increased HIF-1α and VEGF staining in perivascular regions of the anemic cerebral cortex and an increase in the number of nNOS-positive cerebral cortical cells (3.2 ± 1.0-fold, P < 0.001). The nNOS-positive cells costained with the neuronal marker, Neu-N, but not with the astrocytic marker glial fibrillary acidic protein (GFAP). These nNOS-positive neurons frequently sent axonal projections toward cerebral blood vessels. Conversely, VEGF immunostaining colocalized with both neuronal (NeuN) and astrocytic markers (GFAP). In conclusion, acute normotensive, normoxemic hemodilution increased the levels of HIF-1α protein and mRNA for HIF-1-responsive molecules. nNOS and VEGF protein levels were also increased within the cerebral cortex of anemic rats at clinically relevant hemoglobin concentrations.

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