Haem oxygenase-1 overexpression alters intracellular iron distribution

2012 ◽  
Vol 449 (1) ◽  
pp. 189-194 ◽  
Author(s):  
Lilibeth Lanceta ◽  
Chi Li ◽  
Augustine M. Choi ◽  
John W. Eaton
Keyword(s):  
A549 Cells ◽  
Cell Types ◽  
Receptor Expression ◽  
Protective Effects ◽  
Intracellular Iron ◽  
Ferritin Synthesis ◽  
Redox Active ◽  
Consequent Reduction ◽  
Elevated Expression ◽  
Haem Oxygenase

Induction or ectopic overexpression of HO-1 (haem oxygenase 1) protects against a wide variety of disorders. These protective effects have been variably ascribed to generation of carbon monoxide (released during cleavage of the alpha-methene bridge of haem) and/or to production of the antioxidant bilirubin. We investigated HO-1-overexpressing A549 cells and find that, as expected, HO-1-overexpressing cells are resistant to killing by hydrogen peroxide. Surprisingly, these cells have approximately twice the normal amount of intracellular iron which usually tends to amplify oxidant killing. However, HO-1-overexpressing cells contain only ~25% as much ‘loose’ (probably redox active) iron. Indeed, inhibition of ferritin synthesis [via siRNA (small interfering RNA) directed at the ferritin heavy chain] sensitizes the HO-1-overexpressing cells to peroxide killing. It appears that HO-1 overexpression leads to enhanced destruction of haem, consequent 2–3-fold induction of ferritin, and compensatory increases in transferrin receptor expression and haem synthesis. However, there is no functional haem deficiency because cellular oxygen consumption and catalase activity are similar in both cell types. We conclude that, at least in many cases, the cytoprotective effects of HO-1 induction or forced overexpression may derive from elevated expression of ferritin and consequent reduction of redox active ‘loose’ iron.

Effects of TNF-α and IL-1β on iron metabolism by A549 cells and influence on cytotoxicity

1999 ◽  
Vol 277 (2) ◽  
pp. L257-L263 ◽  
Author(s):  
Igor M. Smirnov ◽  
Kirstin Bailey ◽  
Carol H. Flowers ◽  
Ned W. Garrigues ◽  
Lewis J. Wesselius
Keyword(s):  
Cell Death ◽  
Lactate Dehydrogenase ◽  
Iron Metabolism ◽  
Iron Uptake ◽  
A549 Cells ◽  
Receptor Expression ◽  
Alveolar Cells ◽  
Lactate Dehydrogenase Release ◽  
Ferritin Synthesis ◽  
Tnf Α

Extracellular iron, which is predominantly bound by transferrin, is present in low concentrations within alveolar structures, and concentrations are increased in various pulmonary disorders. Iron accumulation by cells can promote oxidative injury. However, the synthesis of ferritin stimulated by metal exposure for intracellular iron storage is normally protective. The cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β may alter iron metabolism by alveolar cells. In this study, we assessed the effects of TNF-α and IL-1β on iron metabolism with a cell line with properties of type 2 alveolar epithelial cells (A549) exposed to non-transferrin-bound (NTBI; FeSO4) or transferrin-bound (TBI) iron. In addition, we assessed the cytotoxicity of these exposures by measuring the cell accumulation of malondialdehyde (MDA), a product of lipid peroxidation, and cell death (MTT assay and lactate dehydrogenase release). A549 cells treated with NTBI or TBI in concentrations up to 40 μM accumulated iron and synthesized predominantly L-type ferritin without accumulation of MDA or cell death. Treatment of A549 cells with TNF-α (20 ng) or IL-1β (20 ng) decreased cell transferrin-receptor expression and induced synthesis of H-type ferritin. TNF-α and IL-1β decreased the uptake of TBI; however, the uptake of NTBI was increased. Both cytokines enhanced total ferritin synthesis (H plus L types) in response to iron treatments due to enhanced synthesis of H-type ferritin. Coexposure to TNF-α and NTBI, but not to TBI, induced MDA accumulation and greater cytotoxicity (MTT and lactate dehydrogenase release) than TNF-α alone. These findings indicate that TNF-α and IL-1β modulate iron uptake by A549 cells, with differing effects on TBI and NTBI, as well as on H-ferritin synthesis. Enhanced iron uptake induced by TNF-α and NTBI was also associated with increased cytotoxicity to A549 cells.

Haem oxygenase-1: a target for dietary antioxidants

2004 ◽  
Vol 32 (6) ◽  
pp. 1003-1005 ◽  
Author(s):  
R.M. Ogborne ◽  
S.A. Rushworth ◽  
C.A. Charalambos ◽  
M.A. O'Connell
Keyword(s):  
Stress Response ◽  
Animal Models ◽  
Vascular Disease ◽  
Cell Types ◽  
Protective Role ◽  
Dietary Therapy ◽  
Protective Effects ◽  
Dietary Antioxidants ◽  
Naturally Occurring ◽  
Haem Oxygenase

HO-1 (haem oxygenase-1) is a stress-response enzyme involved in the catabolism of haem. In animal models, it plays a key protective role in vascular disease. HO-1 has anti-inflammatory effects in macrophages and is induced by a range of stimuli, including antioxidants, in various cell types. As dietary antioxidants are considered to be beneficial in vascular disease, their protective effects may occur through induction of HO-1. Emerging evidence suggests that a range of dietary and other naturally occurring antioxidants stimulate HO-1 expression in various cell types, although regulation by these compounds has not been investigated in detail. These studies suggest that HO-1 may be a target for dietary therapy in vascular disease.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

scholarly journals Human Immunodeficiency Viruses Pseudotyped with SARS-CoV-2 Spike Proteins Infect a Broad Spectrum of Human Cell Lines through Multiple Entry Mechanisms

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 953
Author(s):  
Chuan Xu ◽  
Annie Wang ◽  
Ke Geng ◽  
William Honnen ◽  
Xuening Wang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Viral Entry ◽  
Broad Spectrum ◽  
A549 Cells ◽  
Cell Types ◽  
Pseudotyped Virus ◽  
Angiotensin Converting Enzyme 2 ◽  
Human Immunodeficiency Viruses ◽  
Tyrosine Protein Kinase ◽  
Overexpressing Cell

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), enters cells through attachment to the human angiotensin converting enzyme 2 (hACE2) via the receptor-binding domain (RBD) in the surface/spike (S) protein. Several pseudotyped viruses expressing SARS-CoV-2 S proteins are available, but many of these can only infect hACE2-overexpressing cell lines. Here, we report the use of a simple, two-plasmid, pseudotyped virus system comprising a SARS-CoV-2 spike-expressing plasmid and an HIV vector with or without vpr to investigate the SARS-CoV-2 entry event in various cell lines. When an HIV vector without vpr was used, pseudotyped SARS-CoV-2 viruses produced in the presence of fetal bovine serum (FBS) were able to infect only engineered hACE2-overexpressing cell lines, whereas viruses produced under serum-free conditions were able to infect a broader range of cells, including cells without hACE2 overexpression. When an HIV vector containing vpr was used, pseudotyped viruses were able to infect a broad spectrum of cell types regardless of whether viruses were produced in the presence or absence of FBS. Infection sensitivities of various cell types did not correlate with mRNA abundance of hACE2, TMPRSS2, or TMPRSS4. Pseudotyped SARS-CoV-2 viruses and replication-competent SARS-CoV-2 virus were equally sensitive to neutralization by an anti-spike RBD antibody in cells with high abundance of hACE2. However, the anti-spike RBD antibody did not block pseudotyped viral entry into cell lines with low abundance of hACE2. We further found that CD147 was involved in viral entry in A549 cells with low abundance of hACE2. Thus, our assay is useful for drug and antibody screening as well as for investigating cellular receptors, including hACE2, CD147, and tyrosine-protein kinase receptor UFO (AXL), for the SARS-CoV-2 entry event in various cell lines.

scholarly journals Metabolic activation and colitis pathogenesis is prevented by lymphotoxin β receptor expression in neutrophils

2021 ◽  
Author(s):  
Thomas Riffelmacher ◽  
Daniel A. Giles ◽  
Sonja Zahner ◽  
Martina Dicker ◽  
Alexander Y. Andreyev ◽  
...  
Keyword(s):  
Severe Disease ◽  
Metabolic Activation ◽  
Cell Types ◽  
Receptor Expression ◽  
Neutrophil Accumulation ◽  
Functional Studies ◽  
Mitochondrial Ros ◽  
Tnf Superfamily ◽  
Β Receptor ◽  
Lymphotoxin Beta Receptor

AbstractInflammatory bowel disease is characterized by an exacerbated intestinal immune response, but the critical mechanisms regulating immune activation remain incompletely understood. We previously reported that the TNF-superfamily molecule TNFSF14 (LIGHT) is required for preventing severe disease in mouse models of colitis. In addition, deletion of lymphotoxin beta receptor (LTβR), which binds LIGHT, also led to aggravated colitis pathogenesis. Here, we aimed to determine the cell type(s) requiring LTβR and the mechanism critical for exacerbation of colitis. Specific deletion of LTβR in neutrophils (LTβRΔN), but not in several other cell types, was sufficient to induce aggravated colitis and colonic neutrophil accumulation. Mechanistically, RNA-Seq analysis revealed LIGHT-induced suppression of cellular metabolism, and mitochondrial function, that was dependent on LTβR. Functional studies confirmed increased mitochondrial mass and activity, associated with excessive mitochondrial ROS production and elevated glycolysis at steady-state and during colitis. Targeting these metabolic changes rescued exacerbated disease severity. Our results demonstrate that LIGHT signals to LTβR on neutrophils to suppress metabolic activation and thereby prevents exacerbated immune pathogenesis during colitis.

scholarly journals The Biology of Vasopressin

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 89
Author(s):  
Samantha Sparapani ◽  
Cassandra Millet-Boureima ◽  
Joshua Oliver ◽  
Kathy Mu ◽  
Pegah Hadavi ◽  
...  
Keyword(s):  
Parental Behavior ◽  
Cell Types ◽  
G Protein Coupled Receptors ◽  
Receptor Expression ◽  
Evolutionarily Conserved ◽  
Terrestrial Environments ◽  
Intracellular Vesicles ◽  
G Protein Coupled ◽  
Neuropsychiatric Conditions ◽  
Vasopressin Synthesis

Vasopressins are evolutionarily conserved peptide hormones. Mammalian vasopressin functions systemically as an antidiuretic and regulator of blood and cardiac flow essential for adapting to terrestrial environments. Moreover, vasopressin acts centrally as a neurohormone involved in social and parental behavior and stress response. Vasopressin synthesis in several cell types, storage in intracellular vesicles, and release in response to physiological stimuli are highly regulated and mediated by three distinct G protein coupled receptors. Other receptors may bind or cross-bind vasopressin. Vasopressin is regulated spatially and temporally through transcriptional and post-transcriptional mechanisms, sex, tissue, and cell-specific receptor expression. Anomalies of vasopressin signaling have been observed in polycystic kidney disease, chronic heart failure, and neuropsychiatric conditions. Growing knowledge of the central biological roles of vasopressin has enabled pharmacological advances to treat these conditions by targeting defective systemic or central pathways utilizing specific agonists and antagonists.

scholarly journals Application of Humanized Zebrafish Model in the Suppression of SARS-CoV-2 Spike Protein Induced Pathology by Tri-Herbal Medicine Coronil via Cytokine Modulation

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5091
Author(s):  
Acharya Balkrishna ◽  
Siva Kumar Solleti ◽  
Sudeep Verma ◽  
Anurag Varshney
Keyword(s):  
Herbal Medicine ◽  
High Performance ◽  
Normal Skin ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Spike Protein ◽  
Protective Effects ◽  
Cell Degeneration ◽  
Zebrafish Model ◽  
Tnf Α

Zebrafish has been a reliable model system for studying human viral pathologies. SARS-CoV-2 viral infection has become a global chaos, affecting millions of people. There is an urgent need to contain the pandemic and develop reliable therapies. We report the use of a humanized zebrafish model, xeno-transplanted with human lung epithelial cells, A549, for studying the protective effects of a tri-herbal medicine Coronil. At human relevant doses of 12 and 58 µg/kg, Coronil inhibited SARS-CoV-2 spike protein, induced humanized zebrafish mortality, and rescued from behavioral fever. Morphological and cellular abnormalities along with granulocyte and macrophage accumulation in the swim bladder were restored to normal. Skin hemorrhage, renal cell degeneration, and necrosis were also significantly attenuated by Coronil treatment. Ultra-high-performance liquid chromatography (UHPLC) analysis identified ursolic acid, betulinic acid, withanone, withaferine A, withanoside IV–V, cordifolioside A, magnoflorine, rosmarinic acid, and palmatine as phyto-metabolites present in Coronil. In A549 cells, Coronil attenuated the IL-1β induced IL-6 and TNF-α cytokine secretions, and decreased TNF-α induced NF-κB/AP-1 transcriptional activity. Taken together, we show the disease modifying immunomodulatory properties of Coronil, at human equivalent doses, in rescuing the pathological features induced by the SARS-CoV-2 spike protein, suggesting its potential use in SARS-CoV-2 infectivity.

scholarly journals Effect of nitric oxide on expression of transferrin receptor and ferritin and on cellular iron metabolism in K562 human erythroleukemia cells

Blood ◽  
1995 ◽  
Vol 85 (10) ◽  
pp. 2962-2966 ◽  
Author(s):  
R Oria ◽  
L Sanchez ◽  
T Houston ◽  
MW Hentze ◽  
FY Liew ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Iron Metabolism ◽  
Transferrin Receptor ◽  
Regulatory Protein ◽  
Inhibitory Effect ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Intracellular Iron ◽  
Cellular Iron ◽  
Erythroleukemia Cells

Nitric oxide (NO) is known to increase the affinity of the intracellular iron-regulatory protein (IRP) for iron-response elements (IREs) in transferrin receptor and ferritin mRNAs, suggesting that it may act as a regulator of cellular iron metabolism. In this study, exogenous NO produced by adding the NO-generator S-nitroso-N-acetyl penicillamine gave a dose-dependent upregulation of transferrin receptor expression by K562 erythroleukemia cells and increased levels of transferrin receptor mRNA. NO did not affect the affinity of transferrin binding by the transferrin receptor. NO alone did not alter intracellular ferritin levels, but it did abrogate the inhibitory effect of the iron chelator desferrioxamine and potentiated the stimulatory effect of additional iron. NO also caused some increase in ferritin mRNA levels, which might mask any IRP-/IRE-mediated inhibitory effect of NO on ferritin translation. Although NO did not affect net iron uptake, it increased release of iron from K562 cells pulsed previously with 59Fe, and subcellular fractionation showed that it also increased the proportion of intracellular iron bound to ferritin. These findings provide direct evidence that NO can affect cellular iron metabolism and suggest that NO produced in vivo by activated bone marrow macrophages might affect erythropoiesis.

scholarly journals Pregnancy-enhanced Ca2+ responses to ATP in uterine artery endothelial cells is due to greater capacitative Ca2+ entry rather than altered receptor coupling

2006 ◽  
Vol 190 (2) ◽  
pp. 373-384 ◽  
Author(s):  
Shannon M Gifford ◽  
Fu-Xian Yi ◽  
Ian M Bird
Keyword(s):  
Endothelial Cells ◽  
Uterine Artery ◽  
Purinergic Receptor ◽  
Cell Types ◽  
P2y Receptors ◽  
Receptor Expression ◽  
Receptor Subtype ◽  
Initial Transient ◽  
Receptor Coupling ◽  
Specific Variation

Uterine artery endothelial cells (UAEC) derived from pregnant (P-UAEC) and nonpregnant (NP-UAEC) ewes retain pregnancy-specific differences in cell signaling as well as vasodilator production through passage 4. In particular, when P- and NP-UAEC are stimulated with ATP over a 2.5 min recording period, they exhibit similar initial transient peaks in the intracellular free Ca2+ concentration ([Ca2+]i), but the P-UAEC show a heightened sustained phase. In order to establish whether thiswas due to an altered subclass of purinergic receptor (P2), both the dose dependencyof [Ca2+]i responses to ADP and UTP and the profile of purinergic receptor expression are determined in NP- and P-UAEC. Our findings indicate that while several isoforms of P2X and P2Y receptors are present, it is P2Y2 that is responsible for the ATP-induced initial transient peak in both cell types. We also characterized several key components of the ATP-induced Ca2+ signaling cascade, including the inositol 1,4,5-trisphosphate receptor and G-proteins, but could not confirm any pregnancy-specific variation in the protein expression that correlated with pregnancy-specific differences in prolonged Ca2+ signaling. We thus investigated whether such a difference may be inherent to the cell itself rather than specific to the purinergic receptor-signaling pathway. Using thapsigargin (Tg), we were able to demonstrate that the initial Tg-sensitive intracellular pool of Ca2+is nearly identical with the capacity in both cell types, but the P-UAEC is nonetheless capable of greater capacitative Ca2+ entry (CCE) than NP-UAEC. Furthermore, CCE induced by Tg could be dramatically inhibited by 2-aminoethoxydiphenyl borate, suggesting a role for store-operated channels in the ATP-induced [Ca2+]i response. We conclude that changes at the level of capacitative entry mechanisms rather than switching of receptor subtype or coupling to phospholipase C underlies pregnancy adaptation of UAEC at the level of Ca2+signaling.

Fibronectin is overproduced by keloid fibroblasts during abnormal wound healing

1989 ◽  
Vol 9 (4) ◽  
pp. 1642-1650
Author(s):  
M Babu ◽  
R Diegelmann ◽  
N Oliver
Keyword(s):  
Wound Healing ◽  
State Level ◽  
Cell Types ◽  
Relative Increase ◽  
Receptor Expression ◽  
Glucocorticoid Treatment ◽  
Fibronectin Receptor ◽  
Coordinate Regulation ◽  
Extracellular Matrix Components ◽  
Keloid Fibroblasts

Wound healing in certain individuals leads to the development of keloid tumors which exhibit abnormal collagen metabolism and an increased abundance of extracellular matrix components. Comparison of fibronectin levels in fibroblasts derived from keloids and normal dermis revealed a relative increase in intracellular and extracellular fibronectin in the keloid-derived cells. While fibronectin was similarly processed, compartmentalized, and degraded by both cell types, fibronectin biosynthesis was found to be accelerated as much as fourfold in keloid fibroblasts due to a corresponding increase in the amount of accumulated fibronectin mRNA. These changes account for the elevated steady-state level of the molecule in keloid fibroblasts and suggest that increased fibronectin in keloid lesions is due to overproduction by the wound-healing fibroblasts. Glucocorticoid treatment stimulated fibronectin biosynthesis in both normal and keloid fibroblasts. However, the amount of stimulation was less for the keloid-derived cells, indicating a limitation on maximal rates of fibronectin biosynthesis. These observations suggest that separate mechanisms act to control basal and maximal rates of fibronectin production. Biosynthesis of the 140-kilodalton fibronectin receptor was also found to be increased in keloid fibroblasts, suggesting some level of coordinate regulation for fibronectin and fibronectin receptor expression.

Sign in / Sign up

Export Citation Format

Share Document