The source of heme for vascular heme oxygenase I: heme uptake in rat aorta

2004 ◽  
Vol 82 (4) ◽  
pp. 209-217 ◽  
Author(s):  
Loc Bui ◽  
Kimberly Rish ◽  
Kinga Jaronczyk ◽  
Stephane Bourque ◽  
Brian E McLaughlin ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Heme Oxygenase ◽  
Plasma Proteins ◽  
De Novo ◽  
Soluble Guanylyl Cyclase ◽  
Rat Aorta ◽  
Aortic Tissue ◽  
Heme Uptake

During the last decade, heme oxygenase (HO) and carbon monoxide (CO) have garnered substantial research interest in terms of cell and organ regulation, especially as they bear on the central nervous system, organ transplantation, and the cardiovascular system. While the enzymatic mechanism, substrates, and products of HO are well known, it is not clear whether the cardiovascular system derives its supply of the heme substrate through de novo synthesis or uptake from the extracellular milieu. The objective of the present study was to test the latter possibility in rat aorta and to determine the influence of plasma proteins that bind heme in vivo, viz. hemopexin and albumin. Aortic tissue was exposed to [14C]heme in vitro, and the concentration and time dependence of heme uptake was assessed. The presence of hemopexin or albumin in the incubation medium dramatically decreased heme uptake by the aorta. Heme uptake by aortic tissue was not altered after induction of HO-1, which would be expected to increase tissue heme demand. In summary, the rat, isolated aorta was capable of obtaining heme from its external milieu, but this was obtunded in the presence of the plasma proteins hemopexin or albumin. For normal physiological situations, heme uptake may not be a usual source of substrate for vascular HO and hemoenzymes such as nitric oxide synthase, soluble guanylyl cyclase, and cyclooxygenase.Key words: heme uptake, vasculature, heme oxygenase, hemopexin.

scholarly journals Heme proteins mediate the conversion of nitrite to nitric oxide in the vascular wall

2008 ◽  
Vol 295 (2) ◽  
pp. H499-H508 ◽  
Author(s):  
Wael F. Alzawahra ◽  
M. A. Hassan Talukder ◽  
Xiaoping Liu ◽  
Alexandre Samouilov ◽  
Jay L. Zweier
Keyword(s):  
Nitric Oxide ◽  
Heme Proteins ◽  
Soluble Guanylyl Cyclase ◽  
Vascular Wall ◽  
Rat Aorta ◽  
No Production ◽  
Paramagnetic Resonance ◽  
Physiological Importance

Nitric oxide (NO) has been shown to be the endothelium-derived relaxing factor (EDRF), and its impairment contributes to a variety of cardiovascular disorders. Recently, it has been recognized that nitrite can be an important source of NO; however, questions remain regarding the activity and mechanisms of nitrite bioactivation in vessels and its physiological importance. Therefore, we investigated the effects of nitrite on in vivo hemodynamics in rats and in vitro vasorelaxation in isolated rat aorta under aerobic conditions. Studies were performed to determine the mechanisms by which nitrite is converted to NO. In anesthetized rats, nitrite dose dependently decreased both systolic and diastolic blood pressure with a threshold dose of 10 μM. Similarly, nitrite (10 μM-2 mM) caused vasorelaxation of aortic rings, and NO was shown to be the intermediate factor responsible for this activity. With the use of electrochemical as well as electron paramagnetic resonance (EPR) spectroscopy techniques NO generation was measured from isolated aortic vessels following nitrite treatment. Reduction of nitrite to NO was blocked by heating the vessel, suggesting that an enzymatic process is involved. Organ chamber experiments demonstrated that aortic relaxation induced by nitrite could be blocked by both hemoglobin and soluble guanylyl cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ). In addition, both electrochemical and EPR spin-trapping measurements showed that ODQ inhibits nitrite-mediated NO production. These findings thus suggest that nitrite can be a precursor of EDRF and that sGC or other heme proteins inhibited by ODQ catalyze the reduction of nitrite to NO.

The source of heme for vascular heme oxygenase II: de novo heme biosynthesis in rat aorta

2004 ◽  
Vol 82 (4) ◽  
pp. 218-224 ◽  
Author(s):  
Kinga Jaronczyk ◽  
Loc Bui ◽  
Jonathan M Soong ◽  
Brian E McLaughlin ◽  
Gerald S Marks ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Heme Oxygenase ◽  
De Novo ◽  
Aminolevulinic Acid ◽  
Soluble Guanylyl Cyclase ◽  
Rat Aorta ◽  
Heme Biosynthesis ◽  
Activity Levels ◽  
Sprague Dawley ◽  
Prosthetic Group

Heme is an essential prosthetic group or substrate for many proteins, including hemoglobin, and hemo enzymes such as nitric oxide synthase, soluble guanylyl cyclase, and heme oxygenase (HO). HO is responsible for the breakdown of heme into equimolar amounts of biliverdin, iron, and carbon monoxide, the latter of which is thought to play a role in the regulation of vascular tone. It is not clear whether the source of heme for cardiovascular functions is derived from uptake from the extracellular milieu or synthesis. In this study, we tested the hypothesis that blood vessels obtain their supply of heme for HO through de novo synthesis. Adult male Sprague–Dawley rat aorta was incubated at 37 °C in Krebs' solution with 1 µM [14C]δ-aminolevulinic acid (ALA). [14C]ALA uptake was linear for about 30 min and reached a plateau at approximately 100 min. The radioactivity was incorporated into porphyrins and heme as determined by esterification of 14C-labelled metabolites and thin-layer chromatography. The first and rate-limiting step of heme biosynthesis is catalyzed by ALA synthase (ALA-S), the activity of which was determined in rat aorta using a radiometric assay, ~250 nmol·(g wet mass)–1·h–1. Inducing HO-1 in rat aorta with S-nitroso-N-acetyl penicil la mine (500 µM) did not increase ALA-S activity as compared with basal activity levels of the enzyme. It appears that there is a sufficient amount of heme available under basal ALA-S activity conditions to meet the increased demand for heme resulting from HO-1 induction. These observations indicate that the complete enzymatic pathway for de novo heme biosynthesis resides in rat aorta and furthermore indicate that de novo heme synthesis is capable of supplying a substantial portion of the heme substrate for HO in the aorta.Key words: heme biosynthesis, vasculature, carbon monoxide, heme oxygenase, δ-aminolevulinic acid synthase.

Purification of the Antihemophilic Factor by Gel Filtration on Agarose

1969 ◽  
Vol 22 (03) ◽  
pp. 577-583 ◽  
Author(s):  
M.M.P Paulssen ◽  
A.C.M.G.B Wouterlood ◽  
H.L.M.A Scheffers
Keyword(s):  
Factor Viii ◽  
Plasma Proteins ◽  
Large Scale ◽  
Gel Filtration ◽  
Large Scale Preparation ◽  
Scale Preparation ◽  
Antihemophilic Factor

SummaryFactor VIII can be isolated from plasma proteins, including fibrinogen by chromatography on agarose. The best results were obtained with Sepharose 6B. Large scale preparation is also possible when cryoprecipitate is separated by chromatography. In most fractions containing factor VIII a turbidity is observed which may be due to the presence of chylomicrons.The purified factor VIII was active in vivo as well as in vitro.

Cardiovascular Effects of Micromeria graeca (L.) Benth. ex Rchb in Normotensive and Hypertensive Rats

2020 ◽  
Vol 20 (8) ◽  
pp. 1253-1261
Author(s):  
Mourad Akdad ◽  
Mohamed Eddouks
Keyword(s):  
Blood Pressure ◽  
Cardiovascular System ◽  
Arterial Blood Pressure ◽  
Antihypertensive Activity ◽  
Computer Assisted ◽  
Hypertensive Rats ◽  
Vasorelaxant Effect ◽  
Arterial Blood

Aims: The present study was performed in order to analyze the antihypertensive activity of Micromeria graeca (L.) Benth. ex Rchb. Background: Micromeria graeca (L.) Benth. ex Rchb is an aromatic and medicinal plant belonging to the Lamiaceae family. This herb is used to treat various pathologies such as cardiovascular disorders. Meanwhile, its pharmacological effects on the cardiovascular system have not been studied. Objective: The present study aimed to evaluate the effect of aqueous extract of aerial parts of Micromeria graeca (AEMG) on the cardiovascular system in normotensive and hypertensive rats. Methods: In this study, the cardiovascular effect of AEMG was evaluated using in vivo and in vitro investigations. In order to assess the acute effect of AEMG on the cardiovascular system, anesthetized L-NAME-hypertensive and normotensive rats received AEMG (100 mg/kg) orally and arterial blood pressure parameters were monitored during six hours. In the sub-chronic study, rats were orally treated for one week, followed by blood pressure assessment during one week of treatment. Blood pressure was measured using a tail-cuff and a computer-assisted monitoring device. In the second experiment, isolated rat aortic ring pre-contracted with Epinephrine (EP) or KCl was used to assess the vasorelaxant effect of AEMG. Results: Oral administration of AEMG (100 mg/kg) provoked a decrease of arterial blood pressure parameters in hypertensive rats. In addition, AEMG induced a vasorelaxant effect in thoracic aortic rings pre-contracted with EP (10 μM) or KCl (80 mM). This effect was attenuated in the presence of propranolol and methylene blue. While in the presence of glibenclamide, L-NAME, nifedipine or Indomethacin, the vasorelaxant effect was not affected. Conclusion: This study showed that Micromeria graeca possesses a potent antihypertensive effect and relaxes the vascular smooth muscle through β-adrenergic and cGMP pathways.

scholarly journals Heme Oxygenase-1 Deficiency and Oxidative Stress: A Review of 9 Independent Human Cases and Animal Models

2021 ◽  
Vol 22 (4) ◽  
pp. 1514 ◽  
Author(s):  
Akihiro Yachie
Keyword(s):  
Oxidative Stress ◽  
Animal Models ◽  
Heme Oxygenase ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Pharmacological Intervention ◽  
Heme Oxygenase 1 ◽  
Inflammatory Reactions

Since Yachie et al. reported the first description of human heme oxygenase (HO)-1 deficiency more than 20 years ago, few additional human cases have been reported in the literature. A detailed analysis of the first human case of HO-1 deficiency revealed that HO-1 is involved in the protection of multiple tissues and organs from oxidative stress and excessive inflammatory reactions, through the release of multiple molecules with anti-oxidative stress and anti-inflammatory functions. HO-1 production is induced in vivo within selected cell types, including renal tubular epithelium, hepatic Kupffer cells, vascular endothelium, and monocytes/macrophages, suggesting that HO-1 plays critical roles in these cells. In vivo and in vitro studies have indicated that impaired HO-1 production results in progressive monocyte dysfunction, unregulated macrophage activation and endothelial cell dysfunction, leading to catastrophic systemic inflammatory response syndrome. Data from reported human cases of HO-1 deficiency and numerous studies using animal models suggest that HO-1 plays critical roles in various clinical settings involving excessive oxidative stress and inflammation. In this regard, therapy to induce HO-1 production by pharmacological intervention represents a promising novel strategy to control inflammatory diseases.

Computational study for suppression of CD25/IL-2 interaction

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Moein Dehbashi ◽  
Zohreh Hojati ◽  
Majid Motovali-bashi ◽  
Mazdak Ganjalikhani-Hakemi ◽  
Akihiro Shimosaka ◽  
...  
Keyword(s):  
Small Molecules ◽  
Cancer Progression ◽  
Immune Escape ◽  
De Novo ◽  
Computational Study ◽  
Treg Cells ◽  
Homology Search ◽  
Small Interfering Rnas

AbstractCancer recurrence presents a huge challenge in cancer patient management. Immune escape is a key mechanism of cancer progression and metastatic dissemination. CD25 is expressed in regulatory T (Treg) cells including tumor-infiltrating Treg cells (TI-Tregs). These cells specially activate and reinforce immune escape mechanism of cancers. The suppression of CD25/IL-2 interaction would be useful against Treg cells activation and ultimately immune escape of cancer. Here, software, web servers and databases were used, at which in silico designed small interfering RNAs (siRNAs), de novo designed peptides and virtual screened small molecules against CD25 were introduced for the prospect of eliminating cancer immune escape and obtaining successful treatment. We obtained siRNAs with low off-target effects. Further, small molecules based on the binding homology search in ligand and receptor similarity were introduced. Finally, the critical amino acids on CD25 were targeted by a de novo designed peptide with disulfide bond. Hence we introduced computational-based antagonists to lay a foundation for further in vitro and in vivo studies.

scholarly journals EXTH-51. ANTI-INVASIVE EFFICACY AND SURVIVAL BENEFIT OF THE YAP-TEAD INHIBITOR VERTEPORFIN IN PRECLINICAL GLIOBLASTOMA MODELS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii98-ii98
Author(s):  
Anne Marie Barrette ◽  
Alexandros Bouras ◽  
German Nudelman ◽  
Zarmeen Mussa ◽  
Elena Zaslavsky ◽  
...  
Keyword(s):  
Survival Benefit ◽  
De Novo ◽  
Epithelial Mesenchymal Transition ◽  
Intraperitoneal Administration ◽  
Standard Of Care ◽  
Tumor Burden ◽  
Mesenchymal Transition ◽  
Protein Levels

Abstract Glioblastoma (GBM) remains an incurable disease, in large part due to its malignant infiltrative spread, and current clinical therapy fails to target the invasive nature of tumor cells in disease progression and recurrence. Here, we use the YAP-TEAD inhibitor Verteporfin to target a convergence point for regulating tumor invasion/metastasis and establish the robust anti-invasive therapeutic efficacy of this FDA-approved drug and its survival benefit across several preclinical glioma models. Using patient-derived GBM cells and orthotopic xenograft models (PDX), we show that Verteporfin treatment disrupts YAP/TAZ-TEAD activity and processes related to cell adhesion, migration and epithelial-mesenchymal transition. In-vitro, Verteporfin impairs tumor migration, invasion and motility dynamics. In-vivo, intraperitoneal administration of Verteporfin in mice with orthotopic PDX tumors shows consistent drug accumulation within the brain and decreased infiltrative tumor burden, across three independent experiments. Interestingly, PDX tumors with impaired invasion after Verteporfin treatment downregulate CDH2 and ITGB1 adhesion protein levels within the tumor microenvironment. Finally, Verteporfin treatment confers survival benefit in two independent PDX models: as monotherapy in de-novo GBM and in combination with standard-of-care chemoradiation in recurrent GBM. These findings indicate potential therapeutic value of this FDA-approved drug if repurposed for GBM patients.

scholarly journals Unraveling the In Vivo Protein Corona

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 132
Author(s):  
Johanna Simon ◽  
Gabor Kuhn ◽  
Michael Fichter ◽  
Stephan Gehring ◽  
Katharina Landfester ◽  
...  
Keyword(s):  
Plasma Proteins ◽  
Ex Vivo ◽  
Protein Corona ◽  
Blood Proteins ◽  
Therapeutic Application ◽  
Complex Situation ◽  
Ex Vivo Approach ◽  
In Vivo Administration

Understanding the behavior of nanoparticles upon contact with a physiological environment is of urgent need in order to improve their properties for a successful therapeutic application. Most commonly, the interaction of nanoparticles with plasma proteins are studied under in vitro conditions. However, this has been shown to not reflect the complex situation after in vivo administration. Therefore, here we focused on the investigation of magnetic nanoparticles with blood proteins under in vivo conditions. Importantly, we observed a radically different proteome in vivo in comparison to the in vitro situation underlining the significance of in vivo protein corona studies. Next to this, we found that the in vivo corona profile does not significantly change over time. To mimic the in vivo situation, we established an approach, which we termed “ex vivo” as it uses whole blood freshly prepared from an animal. Overall, we present a comprehensive analysis focusing on the interaction between nanoparticles and blood proteins under in vivo conditions and how to mimic this situation with our ex vivo approach. This knowledge is needed to characterize the true biological identity of nanoparticles.

scholarly journals PAICS contributes to gastric carcinogenesis and participates in DNA damage response by interacting with histone deacetylase 1/2

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Nan Huang ◽  
Chang Xu ◽  
Liang Deng ◽  
Xue Li ◽  
Zhixuan Bian ◽  
...  
Keyword(s):  
Dna Damage ◽  
Histone Deacetylase ◽  
Dna Damage Response ◽  
De Novo ◽  
Dna Damage Repair ◽  
Histone Deacetylase 1 ◽  
Damage Repair ◽  
Damage Response

AbstractPhosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an essential enzyme involved in de novo purine biosynthesis, is connected with formation of various tumors. However, the specific biological roles and related mechanisms of PAICS in gastric cancer (GC) remain unclear. In the present study, we identified for the first time that PAICS was significantly upregulated in GC and high expression of PAICS was correlated with poor prognosis of patients with GC. In addition, knockdown of PAICS significantly induced cell apoptosis, and inhibited GC cell growth both in vitro and in vivo. Mechanistic studies first found that PAICS was engaged in DNA damage response, and knockdown of PAICS in GC cell lines induced DNA damage and impaired DNA damage repair efficiency. Further explorations revealed that PAICS interacted with histone deacetylase HDAC1 and HDAC2, and PAICS deficiency decreased the expression of DAD51 and inhibited its recruitment to DNA damage sites by impairing HDAC1/2 deacetylase activity, eventually preventing DNA damage repair. Consistently, PAICS deficiency enhanced the sensitivity of GC cells to DNA damage agent, cisplatin (CDDP), both in vitro and in vivo. Altogether, our findings demonstrate that PAICS plays an oncogenic role in GC, which act as a novel diagnosis and prognostic biomarker for patients with GC.

Hippokampale Estrogensynthese und synaptische Plastizität

e-Neuroforum ◽  
2007 ◽  
Vol 13 (4) ◽  
Author(s):  
Lars Fester ◽  
Janine Prange-Kiel ◽  
Gabriele M. Rune
Keyword(s):  
De Novo ◽  
Synaptische Plastizität

ZusammenfassungUnsere Untersuchungen der letzten Jahre haben gezeigt, dass nicht das Ovar die Quelle für Estrogen induzierte synaptische Plastizität im Hippokampus ist, sondern dieses aus dem Hippokampus selber stammt und haben damit einen Paradigmawechsel eingeleitet, der Estrogen als Neuromodulator unabhängig vom Geschlecht identifiziert. Hippokampale Neurone von Ratten beiderlei Geschlechts sind in der Lage, aus Cholesterol Estrogene de novo zu synthetisieren. Diese hippokampale Estrogensynthese ist sowohl für den Erhalt von Spinesynapsen in vivo als auch in vitro essenziell. Die Hemmung der Estrogensynthese zieht einen Synapsenverlust nach sich und Langzeitpotenzierung ist nicht mehr induzierbar. Die Effekte von hippokampalem Estrogen sind auto-/parakriner Natur, die über die bekannten Estrogenrezeptor-Subtypen, ERα und ERβ, vermittelt werden. Die Regulation der hippokampalen Estrogensynthese erfolgt über GnRH und erklärt die Korrelation der Spinesynapsendichte mit dem weiblichen genitalen Zyklus, die für den Hippokampus spezifisch ist.

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