scholarly journals Obesity and Oral Contraceptives Synergistically Increase Thrombotic Risk By Downregulating Protein S

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4237-4237
Author(s):  
Lekha Thangada ◽  
Manoj Kumar ◽  
Satish Sekhar Pilli ◽  
Rinku Majumder
Keyword(s):  
Oral Contraceptives ◽  
Cobalt Chloride ◽  
Conflicts Of Interest ◽  
Hypoxia Inducible Factor ◽  
Protein S ◽  
Immunoblot Analysis ◽  
Thrombotic Risk ◽  
Hypoxia Inducible Factor 1 ◽  
Two Factors ◽  
Major Producer

Abstract Background: The increased thrombotic effects of estrogen-based oral contraceptives and obesity have been documented independently. However, obesity and oral contraceptives combined are associated with a far greater thrombotic risk, but we have a poor understanding of the mechanism of this greater effect. Increasingly, women are using oral contraceptives, and the national obesity rate has been skyrocketing. Thus, it is imperative to explain how obesity and oral contraceptives work together to significantly elevate thrombotic risk. We know that hypoxia-inducible factor 1-ɑ (HIF-1ɑ) and the estrogen receptor (Erɑ) bind to the promoter of the Protein S gene; binding occurs at sites within ~450 nucleotides of each other, and the two transcription factors downregulate Protein S expression independently. We hypothesize that the two factors, by binding the promoter simultaneously, synergistically downregulate Protein S to a degree much greater than the downregulation mediated by each factor separately. Aims: The goal of this project is determining whether estrogen and obesity-induced hypoxia work synergistically to downregulate Protein S transcription and increase thrombotic risk. Methods: We measured the effects of obesity and oral contraceptives on hepatocarcinoma (HEP G2) cells because the liver is the major producer of Protein S. Estrogen of varying concentrations (25-150 μM) was used to mimic the effects of oral contraceptives, and cobalt chloride of varying concentrations (25-150 μM) was used to stimulate hypoxia and HIF-1ɑ expression. Cells were exposed to estrogen only, cobalt chloride only, and estrogen and cobalt chloride together for 24 hours, after which the cells were harvested and subjected to q-PCR and immunoblot blot analyses to measure Protein S transcription and protein expression. Although cobalt chloride is a reliable inducer of hypoxia and HIF-1ɑ expression, we also performed hypoxia experiments by incubating cells in a chamber with varying O 2 concentrations (20%, 15%, 10%, 5%, 1%). Results and Conclusions: Immunoblot analysis of cells treated with either CoCl 2 and estrogen supplementation revealed a ~20% reduction in Protein S levels compared to control conditions and a more significant reduction in (~60%) Protein S expression in cells treated with estrogen and CoCl 2 together. These results supported our hypothesis that obesity and estrogen-based contraceptives increase thrombotic risk by downregulating anticoagulant Protein S transcription and subsequently decreasing Protein S level. Disclosures No relevant conflicts of interest to declare.

Up-regulation of hypoxia-inducible factor-1 alpha by cobalt chloride prevents hearing loss in noise-exposed mice

2011 ◽  
Vol 31 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Jong Woo Chung ◽  
Jung-Eun Shin ◽  
Kwang Woo Han ◽  
Joong Ho Ahn ◽  
Young-Jin Kim ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cobalt Chloride ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1

Copper-dependent and -independent hypoxia-inducible factor-1 regulation of gene expression

Metallomics ◽  
2014 ◽  
Vol 6 (10) ◽  
pp. 1889-1893 ◽  
Author(s):  
Zhen Zhang ◽  
Liying Qiu ◽  
Chen Lin ◽  
Hong Yang ◽  
Haiying Fu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cobalt Chloride ◽  
Regulation Of Gene Expression ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1

HIF-1 mediated expression of BNIP3 by cobalt chloride is Cu-dependent, but the expression of IGF-2 is Cu-independent.

scholarly journals HIF-1 regulates hypoxia- and insulin-induced expression of apelin in adipocytes

2007 ◽  
Vol 293 (6) ◽  
pp. E1590-E1596 ◽  
Author(s):  
Alexander J. Glassford ◽  
Patrick Yue ◽  
Ahmad Y. Sheikh ◽  
Hyung J. Chun ◽  
Shirin Zarafshar ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
Cobalt Chloride ◽  
Hypoxia Inducible Factor ◽  
Metabolic Responses ◽  
Quantitative Real Time Pcr ◽  
Mouse Embryonic Fibroblasts ◽  
Embryonic Fibroblasts ◽  
Targeted Deletion ◽  
Hypoxia Inducible Factor 1

Apelin, a novel peptide with significant cardioactive properties, is upregulated by insulin in adipocytes. However, the mechanism by which insulin promotes apelin production is unknown. Hypoxia-inducible factor-1 (HIF-1), a heterodimeric transcription factor involved in the angiogenic and metabolic responses to tissue hypoxia, has been shown to be activated by insulin in various settings. We therefore hypothesized that HIF-1 regulates insulin-mediated apelin expression in adipocytes. 3T3-L1 cells were differentiated into adipocytes in culture. For experiments, serum-starved 3T3-L1 cells were exposed to insulin and/or a 1% O2 environment. Apelin expression was assessed using quantitative real-time PCR and ELISA. To directly assess the role of HIF-1 in apelin production, we differentiated mouse embryonic fibroblasts (MEFs) containing a targeted deletion of the HIF-1α gene into adipocytes and measured their response to insulin and hypoxia. Apelin expression in mature 3T3-L1 adipocytes was increased significantly by insulin and was attenuated by pharmacological inhibition of insulin signaling. Exposure of cells to either hypoxia or the chemical HIF activators cobalt chloride (CoCl2) and dimethyloxaloylglycine (DMOG) resulted in significant upregulation of apelin, consistent with a role for HIF in apelin induction. Moreover, hypoxia-, CoCl2-, DMOG-, and insulin-induced apelin expression were all attenuated in differentiated HIF-1α-deficient MEFs. In summary, in cultured 3T3-L1 adipocytes and differentiated MEFs, HIF-1 appears to be involved in hypoxia- and insulin-induced apelin expression.

Effect of second- and third-generation oral contraceptives on the protein C system in the absence or presence of the factor VLeiden mutation: a randomized trial

Blood ◽  
2004 ◽  
Vol 103 (3) ◽  
pp. 927-933 ◽  
Author(s):  
Jeanet M. Kemmeren ◽  
Ale Algra ◽  
Joost C. M. Meijers ◽  
Guido Tans ◽  
Bonno N. Bouma ◽  
...  
Keyword(s):  
Oral Contraceptives ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Third Generation ◽  
Double Blind Trial ◽  
Double Blind ◽  
Thrombotic Risk ◽  
Apc Resistance ◽  
Plausible Mechanism

AbstractA plausible mechanism to explain thrombotic risk differences associated with the use of second- and third-generation oral contraceptives (OCs), particularly in carriers of factor VLeiden, is still lacking. In a double-blind trial, 51 women without and 35 women with factor VLeiden were randomized to either a second- (30 μg ethinylestradiol/150 μg levonorgestrel) or third- (30 μg ethinylestradiol/150 μg desogestrel) generation OC. After 2 cycles of use and a wash-out of 2 cycles, the participants continued with the corresponding progestagen-only preparation. Hemostatic variables that probe the activity of the anticoagulant protein C system were determined. Compared with levonorgestrel, desogestrel-containing OCs significantly decreased protein S and increased activated protein C (APC) resistance in both groups. OCs with desogestrel had the most pronounced effects in carriers of factor VLeiden. Progestagen-only preparations caused changes of anticoagulant parameters opposite to those of combined OCs, which in a number of cases were more pronounced with levonorgestrel. Our data show that progestagens in combined OCs counteract the thrombotic effect of the estrogen component. The higher thrombotic risk associated with third-generation OCs compared with second-generation OCs may be explained by the fact that desogestrel appeared less antithrombotic than levonorgestrel, especially in women with factor VLeiden. (Blood. 2004;103:927-933)

The Potential Role of Galectin-1 in Hypoxia Induced AML Cell Differentiation through C/EBPαa Transcription Regulation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3120-3120
Author(s):  
Meng Zhao ◽  
Xu-Yun Zhao ◽  
Shi-Hua Liao ◽  
Ke-Wen Zhao ◽  
Li-Shun Wang ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Conflicts Of Interest ◽  
Hypoxia Inducible Factor ◽  
Luciferase Assay ◽  
Hypoxia Inducible Factor 1 ◽  
Morphological Criteria ◽  
Interfering Rna ◽  
Simulated Hypoxia ◽  
Mild Hypoxia

Abstract Abstract 3120 Poster Board III-57 Recently we reported that cobalt chloride-simulated hypoxia and mild hypoxia could induce the differentiation of human acute myeloid leukemic (AML) cells probably through hypoxia inducible factor-1 alpha (HIF-1αa) independent of its transcription activity. In this study, we used differential gel electrophoresis to compare the HIF-1αa regulated proteins between conditional induction and absence of HIF-1αa protein in U937T cells. Among all the up-regulated proteins indentified, the mRNA and protein level of galectin-1 was most remarkably changed. Knockdown of galectin-1 partially blocked the differentiation induced by HIF-1αa overexpression in U937T cells as assessed by morphological criteria and differentiation associated-antigens. Notably, reduced expression of C/EBPαa, a critical transcription factor for granulocyte differentiation, could inhibit the up-regulation of galectin-1 induced by HIF-1αa, and inducible expression of C/EBPαa in U937T cells also increased galectin-1 expression. Furthermore, by using the luciferase assay and chromatin immunoprecipitation we localized the binding site of C/EBPαa in the promoter of galectin-1. Finally the role of galectin-1 during chloride-simulated hypoxia and mild hypoxia was addressed by decreasing the expression of galectin-1 with small interfering RNA. Taken together, these results conclude that galectin-1 is required for hypoxia triggered C/EBPαa dependent AML cell differentiation. Disclosures No relevant conflicts of interest to declare.

Naturally Occurring Anticoagulants and Their Association With Thromboembolism In Patients With β-Thalassemia Major

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4792-4792
Author(s):  
Sadia Sultan ◽  
Syed Mohammed Irfan ◽  
Rozina Zeeshan
Keyword(s):  
Protein C ◽  
Complete Blood Count ◽  
Conflicts Of Interest ◽  
Protein S ◽  
Thrombotic Risk ◽  
C Protein ◽  
Positive Correlation ◽  
The Mean ◽  
And Control

Introduction Hypercoagulopathy and thromboembolic manifestations are being increasing acknowledged in transfusion dependent thalassemics; both intermedia and major. Studies in preceding decade have shown that hemostatic alterations including natural anticoagulant deficiency obligate thalassemic for thromboembolism. The aim of our study is to determine the status of natural anticoagulants and their association with thromboembolism during follow up. Method This is a prospective case-control study, during which 40 cases and 30 controls were registered between Jan 2009 to Dec 2009. Complete blood count, protein C, protein S, antithrombin, serum ferritin, liver function test; HbsAg and Anti HCV were determined. Patients were followed till 30th June 2012 for thromboembolic disease. Data was entered and analyzed using SPSS version 17. The results were expressed as mean ± SD for quantitative variables and qualitative variables are presented as frequency & percentages. Student‘t’ test was applied for the comparison of means. We also computed spearman correlation at 5% level of significance to identify relationship between the deficiency of natural anticoagulants with maternal characteristics, hematological parameters and biochemical markers. Chi- square test was applied for correlation of prothrombotic markers with hepatitis B & C. Results The mean age of patients and control was 12.30±5.5 and 13.39±4.5 years respectively. There were 21 males and 19 females in patient group. The mean protein C, protein S and antithrombin in patients and control were 58.25±22.5 versus 110.67±22.60 (P<0.001), 67.90±19.58 versus 98.70±21.54 and 89.73±18.09 versus 104.0±10.98 (P<0.001) respectively. Protein C was exceedingly deficient in 65% followed by protein S & antithrombin in 35% and 20% respectively. Protein S deficiency revealed positive correlation with protein C deficiency and hemoglobin ≤ 8 gm% was correlated with antithrombin deficiency(P<0.05). No positive correlation of prothrombotic markers were established with others parameters evaluated. Till June 2012, 7 patients were lost to follow up and 2 died owing to cardiac failure. Of the 31 patients in regular follow up none has experienced thromboembolism both clinically and radiologically. Conclusion Decremented prothrombotic markers, primarily protein C, are implicated in elevated thrombotic risk in TM patients. However we did not encounter thromboembolism in our patients during follow up. We recommend prothrombotic screening and prophylactic anticoagulation in high risk group: bed bound splenectomized, cardiopulmonary complications and post operative. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Desferrioxamine induces erythropoietin gene expression and hypoxia- inducible factor 1 DNA-binding activity: implications for models of hypoxia signal transduction

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3610-3615 ◽  
Author(s):  
GL Wang ◽  
GL Semenza
Keyword(s):  
Signal Transduction ◽  
Dna Binding ◽  
Cobalt Chloride ◽  
De Novo ◽  
Hypoxia Inducible Factor ◽  
Binding Activity ◽  
Ferrous Ammonium Sulfate ◽  
Hypoxia Inducible Factor 1 ◽  
Dna Binding Activity ◽  
Hep3b Cells

Abstract Erythropoietin (EPO) gene transcription is activated in kidney cells in vivo and in Hep3B cells exposed to hypoxia or cobalt chloride. Hypoxia- inducible factor 1 (HIF-1) is a nuclear factor that binds to the hypoxia-inducible enhancer of the EPO gene at a site that is required for transcriptional activation. HIF-1 DNA-binding activity is induced by hypoxia or cobalt chloride treatment of Hep3B cells. We report that treatment of Hep3B cells with desferrioxamine (DFX) induced HIF-1 activity and EPO RNA expression with kinetics similar to the induction of HIF-1 by hypoxia or cobalt chloride. Induction by each of these stimuli was inhibited by cycloheximide, indicating a requirement for de novo protein synthesis. DFX appears to induce HIF-1 by chelating iron as induction was inhibited by coadministration of ferrous ammonium sulfate. DFX administration to mice transiently increased EPO RNA levels in the kidney. As previously shown for hypoxia and cobalt treatment, DFX also induced HIF-1 activity in non-EPO-producing cells, suggesting the existence of a common hypoxia signal-transduction pathway leading to HIF-1 induction in different cell types.

scholarly journals Constitutive Expression of Hypoxia Inducible Factor Downregulates the Anticoagulant Protein S in a Unique Chuvash Polycythemia Population with Erythrocytosis

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4259-4259
Author(s):  
Devin Melancon ◽  
Verima Pereira ◽  
Victor R. Gordeuk ◽  
Rinku Majumder
Keyword(s):  
Total Protein ◽  
Research Funding ◽  
Hypoxia Inducible Factor ◽  
Vascular Complications ◽  
Constitutive Expression ◽  
Protein S ◽  
Thrombotic Risk ◽  
Free Protein ◽  
Hepcidin Expression ◽  
Vascular Abnormalities

Abstract Background: Chuvash polycythemia is a hematological disorder present worldwide but endemic to the Chuvash population, a Turkish ethnic group in Russia. The disorder is caused by a homozygous germline mutation (R200W) in the von Hippel Lindau gene (1,2). This mutation impairs binding of pVHL to hypoxia-inducible factor 1-alpha (HIF-1a); lack of this interaction prevents degradation of HIF-1a (2,3). The resultant upregulation of HIF-1a, even in a normal oxygen state, increases the activity of erythropoietin, thereby causing polycythemia (2,3). Affected individuals experience increased rates of arterial and venous thrombosis unrelated to the increased concentration of hemoglobin (4,5). Aims: To determine whether upregulation of HIF-1a in Chuvash polycythemia individuals causes a decreased level of the antithrombotic Protein S. A decreased level of Protein S may explain the increased risks of thrombotic events and vascular abnormalities in the Chuvash population. Methods: Enzyme-linked immunosorbent assays (ELISA) were performed to measure total Protein S concentration in Chuvash and control plasma. Immunoblotting was performed to confirm the ELISA measurements. Additional assays to measure free Protein S and thrombin generation assays with and without Protein S will be performed to determine whether Chuvash plasma has low free Protein S and whether Protein S supplementation will improve the thrombotic phenotypes. Results: Total Protein S concentration measured by ELISA was lower in Chuvash individuals compared with controls. In addition, we have completed immunoblotting of seven Chuvash samples and three control samples. Our results indicated that Chuvash plasma had lower amounts of Protein S compared with the controls. Immunoblotting of additional Chuvash samples is in progress, and we are planning to measure the free Protein S in Chuvash samples. Conclusion: Our preliminary results suggest a decreased level of total Protein S in individuals with Chuvash polycythemia. Because an increased hemoglobin concentration does not increase the rates of thromboembolic events in this population, our finding of a reduced amount of anticoagulant Protein S may explain the hypercoagulability that Chuvash individuals experience. References  Gordeuk, V.R., et al., Chuvash polycythemia VHLR200W mutation is associated with down-regulation of hepcidin expression. Blood, 2011. 118(19): p. 5278-82. Gordeuk, V.R., et al., Congenital disorder of oxygen sensing: association of the homozygous Chuvash polycythemia VHL mutation with thrombosis and vascular abnormalities but not tumors. Blood, 2004. 103(10): p. 3924-32. Gordeuk, V.R. and J.T. Prchal, Vascular complications in Chuvash polycythemia. Semin Thromb Hemost, 2006. 32(3): p. 289-94. Sergueeva, A., et al., Prospective study of thrombosis and thrombospondin-1 expression in Chuvash polycythemia. Haematologica, 2017. 102(5): p. e166-e169. Gordeuk, V.R., N.S. Key, and J.T. Prchal, Re-evaluation of hematocrit as a determinant of thrombotic risk in erythrocytosis. Haematologica, 2019. 104(4): p. 653-658. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy.

scholarly journals Desferrioxamine induces erythropoietin gene expression and hypoxia- inducible factor 1 DNA-binding activity: implications for models of hypoxia signal transduction

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3610-3615 ◽  
Author(s):  
GL Wang ◽  
GL Semenza
Keyword(s):  
Signal Transduction ◽  
Dna Binding ◽  
Cobalt Chloride ◽  
De Novo ◽  
Hypoxia Inducible Factor ◽  
Binding Activity ◽  
Ferrous Ammonium Sulfate ◽  
Hypoxia Inducible Factor 1 ◽  
Dna Binding Activity ◽  
Hep3b Cells

Erythropoietin (EPO) gene transcription is activated in kidney cells in vivo and in Hep3B cells exposed to hypoxia or cobalt chloride. Hypoxia- inducible factor 1 (HIF-1) is a nuclear factor that binds to the hypoxia-inducible enhancer of the EPO gene at a site that is required for transcriptional activation. HIF-1 DNA-binding activity is induced by hypoxia or cobalt chloride treatment of Hep3B cells. We report that treatment of Hep3B cells with desferrioxamine (DFX) induced HIF-1 activity and EPO RNA expression with kinetics similar to the induction of HIF-1 by hypoxia or cobalt chloride. Induction by each of these stimuli was inhibited by cycloheximide, indicating a requirement for de novo protein synthesis. DFX appears to induce HIF-1 by chelating iron as induction was inhibited by coadministration of ferrous ammonium sulfate. DFX administration to mice transiently increased EPO RNA levels in the kidney. As previously shown for hypoxia and cobalt treatment, DFX also induced HIF-1 activity in non-EPO-producing cells, suggesting the existence of a common hypoxia signal-transduction pathway leading to HIF-1 induction in different cell types.

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