Oxidative status of platelets in normal and thalassemic blood

2004 ◽  
Vol 92 (11) ◽  
pp. 1052-1059 ◽  
Author(s):  
Johnny Amer ◽  
Eitan Fibach

SummaryChronic platelet activation may be involved in thromboembolic complications, a leading cause of morbidity and mortality in β-thalassemia. Oxidative stress, with the generation of reactive oxygen species (ROS), is suspected to play a role in the pathophysiology of thalassemia and cardiovascular disorders. In the present study, we adapted flow cytometric techniques to measure oxidative state markers, ROS generation and reduced glutathione (GSH) content in platelets. Our results show that platelets obtained from β-thalassemic patients contain higher ROS and lower GSH levels than do platelets from normal donors, indicating a state of oxidative stress. In the absence of any known inherent abnormality in thalassemia platelets, this may be attributed to continuous exposure to oxidative insults from extra-platelet sources. We found that exposure of platelets to oxidants such as hydrogen peroxide and tertbutylhydroperoxide or to the platelet activators thrombin, calcium ionophore or phorbol myristate acetate stimulated the platelets’ oxidative stress.This was also increased by plasma of thalassemia patients, and decreased following treatment of the plasma with the iron-chelator Desferoxamin. Iron and hemin, the levels of which are augmented in plasma of thalassemia patients, stimulated the platelets’ oxidative stress.The oxidative status of the platelets was also affected by red blood cells (RBC); it was higher in normal platelets incubated with thalassemic RBC than with normal RBC. Normal RBC stimulated with hydrogen peroxide had a greater effect on platelets than did unstimulated RBC.The platelets’ oxidative stress was ameliorated by antioxidants such as N-acetyl-L-cysteine and vitamin C. Our findings indicate that in thalassemia, platelets undergo a state of oxidative stress, leading to their activation and potentially to thromboembolic consequences, and suggest that this hypercoagulable state might be treated with antioxidants.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3765-3765
Author(s):  
Johnny Amer ◽  
Eitan Fibach

Abstract Thromboembolic complications, possibly involving chronic platelet activation, are an important cause of morbidity and mortality in beta-thalassemia. Oxidative stress, with the generation of reactive oxygen species (ROS), has been suspected to play a role in the pathophysiology of thalassemia and cardiovascular disorders. Previous investigations demonstrated that ROS profoundly affect platelet function and promote platelet activation. Other studies have shown that platelets themselves produce ROS upon activation. In the present study, we adapted flow cytometric techniques to measure oxidative-state markers, ROS generation and reduced glutathione (GSH), using 2′-7′-dichlorofluorescin diacetate and mercury orange, respectively, in platelets. GSH is the major intracellular antioxidant - an important scavenger of ROS. To exclude non-platelets from analysis, a two-parameter (side light scatter and forward light scatter) gate was set. The identity of the gated cells was verified by immunofluorescence staining for CD41 - a platelet-specific antigen. Using these techniques, the average Mean Fluorescence Channel (MFC) values of platelets from 46 normal donors and 22 beta-thalassemic donors were 176 ± 99 vs. 314 ± 81, respectively, for ROS and 319 ± 87 vs. 113 ± 47, respectively, for GSH. These results show that thalassemic platelets contain higher ROS and lower GSH levels than do normal platelets, indicating a state of oxidative stress. The relationship between platelet activation and oxidative status was determined by treating platelets with thrombin (0.1 U/ml), calcium ionophore (5 μM) or phorbol myristate acetate (400 ng/ml). All these treatments caused platelet activation as well as ROS generation; thalassemic platelets were more responsive than platelets from normal controls. In the absence of any known inherent abnormality in thalassemic platelets, the increased oxidative status was attributable to continuous exposure to oxidative insults from extra-platelet sources. Indeed, further investigation indicated that the oxidative status of normal platelets was increased by thalassemic plasma and was inhibited by the iron-chelator Desferoxamin. Iron and hemin, whose levels are increased in thalassemic plasma, stimulated the platelets’ oxidative stress. This was also affected by RBC: it was higher in normal platelets incubated with thalassemic RBC than when incubated with normal RBC. Normal RBC stimulated with hydrogen peroxide, a treatment which results in an elevated oxidative status, increased platelet ROS to a greater extent (3.3-fold) than did unstimulated RBC. These results suggest that thalassemic RBC, having higher than normal ROS, mediate oxidative stress in platelets directly, probably by contact or close proximity. Platelet oxidative stress was ameliorated by antioxidants such as N-acetyl-L-cysteine and vitamin C. Treatment with these agents of oxidant-stimulated platelets reduced ROS and enhanced the GSH level. The present results indicate that in thalassemia, platelets are in a state of oxidative stress, causing their chronic activation and possibly thromboembolic consequences. This situation may also prevail in other RBC anomalies, such as sickle cell anemia, Polycythemia Vera and Paroxysmal Nocturnal Hemoglobinuria, which are also associated with thromboembolic phenomena. Our findings raise the possibility of using antioxidants in addition to antithrombotic drugs as prophylactic treatment in these diseases.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2632-2632
Author(s):  
Eitan Fibach ◽  
Hussam Ghoti ◽  
Johnny Amer ◽  
Asher Winder ◽  
Eliezer Rachmilewitz

Abstract Myelodysplastic syndrome (MDS) is characterized by refractory cytopenias due to ineffective hematopoiesis. Some patients with severe anemia require multiple blood transfusions and develop iron overload. Consequently, reactive oxygen species (ROS) are generated concomitant with a decrease in cellular antioxidants such as reduced gluthatione (GSH). The generated oxidative stress contributes to cell damage, apoptosis and ineffective hematopoiesis. Using flow cytometry, we measured the oxidative state of RBC, platelets and PMN in 14 low-risk MDS patients and 25 normal donors. The results indicate that the majority of the patients had higher ROS in RBC (2.79-fold) and platelets (2.91-fold) and lower GSH in their RBC (3.4-fold) and platelets (2.1-fold) than normal (p<0.005). As for PMN, there were no significant differences in ROS, although GSH was significantly (p<0.1) lower in MDS compared with normal donors. The oxidative stress in MDS cells could be ameliorated by a short in vitro treatment with the iron-chelators deferrioxamine and deferiprone, or with the anti-oxidant N-acetylcysteine. These results suggest that the decrease in transfusion requirements with increase in platelet and PMN counts in MDS patients treated with deferrioxamine may be due to indirect antioxidant effect of the iron chelator and suggest that treatment with a combination of iron-chelators and anti-oxidants might be more effective. ROS generation and GSH content in MDS blood cells ROS generation and GSH content in MDS blood cells Effect of iron chelations and an antioxidant on the oxidative status of MDS cells Effect of iron chelations and an antioxidant on the oxidative status of MDS cells


2018 ◽  
Vol 46 (1) ◽  
Author(s):  
Nermin Isik ◽  
Ozlem Derinbay Ekici ◽  
Ceylan Ilhan ◽  
Devran Coskun

 Background: Theileriosis is a tick-borne disease caused by Theileria strains of the protozoan species. Buparvaquone is the mostly preferred drug in the treatment theileriosis, while it is safety in sheep, has not been detailed investigated. It has been hypothesized that buparvaquone may show side effects and these effects may be defined some parameters measured from blood in sheep when it is used at the recommended dose and duration. The aim of this research was to determine the effect of buparvaquone on the blood oxidative status, cardiac, hepatic and renal damage and bone marrow function markers.Materials, Methods & Results: In this study, ten adult (> 2 years) Akkaraman rams were used. Healthy rams were placed in paddocks, provided water ad libitum, and fed with appropriate rations during the experiment. Buparvaquone was ad­ministered at the dose of 2.5 mg/kg (IM) intramuscularly twice at 3-day intervals. Blood samples were obtained before (0. h, Control) and after drug administration at 0.25, 0.5, 1, 2, 3, 4 and 5 days. The blood samples were transferred to gel tubes, and the sera were removed (2000 g, 15 min). During the study, the heart rate, respiratory rate, and body temperature were measured at each sampling time. In addition, the animals were clinically observed. Plasma oxidative status mark­ers (Malondialdehyde, total antioxidant status, catalase, glutathione peroxidase, superoxide dismutase), serum cardiac (Troponin I, creatine kinase-MBmass, lactate dehydrogenase), hepatic (Alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase, total protein, albumin, globulin) and renal (Creatinine, blood urea nitrogen) damage markers and hemogram values (white blood cell, red blood cell, platelet, hemogram, hematocrit) were measured. Buparvaquone caused statistically significantly (P < 0.05) increases in the troponin I and blood urea nitrogen levels and fluctuations in alkaline phosphatase activity, but there was no any statistically significance difference determined in the other parameters.Discussion: In this study, buparvaquone was administered two times at a dose of 2.5 mg/kg (IM) at 3-day intervals. Al­though the result was not statistically significant (P > 0.05), it was determined that buparvaquone gradually increased the levels of the main oxidative stress marker, MDA, by approximately 2.8 fold. CAT and GPX levels were also found to have decreased by 2.2 fold. Buparvaquone may cause lipid peroxidation by producing free radicals. Some other antiprotozoal drugs may affect the oxidative status and may increase MDA level and decrease SOD level. In this study, MDA, which is an indicator of lipid peroxidation in vivo, was used to partially detect developing lipid peroxidation. Changes in the levels of reduced GPX and CAT enzymes could be attributed to their use in mediating the hydrogen peroxide detoxification mechanisms. The absence of significant changes in the TAS levels in this study suggests that buparvaquone may partially induce oxidative stress by producing hydrogen peroxide, but no significant changes occurred in the oxidative stress level because of the high antioxidant capacity of sheep. In this study, buparvaquone caused a statistically significant increase (P < 0.05) in the level of Tn-I, which is a marker of specific cardiac damage (P < 0.05), whereas there was no statistically (P > 0.05) significant increase in CK-MBmass. Tn-I and CK-MB levels, which are used to define heart damage in humans, have been successfully used to determine heart damage in sheep. In this research study, the statistically significant increases in Tn-I but not CK-MBmass levels could be considered indicative of mild cardiac damage.Keywords: ram, buparvaquone, safety.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 626
Author(s):  
Li Xiao ◽  
Nobuhiko Miwa

Reactive oxygen species (ROS)-induced oxidative stress in adipose tissue is associated with inflammation and the development of obesity-related metabolic disorders. The aim of this study is to investigate the effects of hydrogen nano-bubble water (HW) on ROS generation, adipogenesis, and interleukin-6 (IL-6) secretion in hydrogen peroxide (H2O2) or phorbol 12-myristate 13-acetate (PMA)-stimulated OP9 adipocytes, and three-dimensional (3D) subcutaneous adipose equivalents. Nanoparticle tracking analysis showed that fresh HW contains 1.17 × 108/mL of nano-sized hydrogen bubbles. Even after 8 to 13 months of storage, approximately half of the bubbles still remained in the water. CellROX® staining showed that HW could diminish H2O2- or PMA-induced intracellular ROS generation in human keratinocytes HaCaT and OP9 cells. We discovered that PMA could markedly increase lipid accumulation to 180% and IL-6 secretion 2.7-fold in OP9 adipocytes. Similarly, H2O2 (5 µM) also significantly stimulated lipid accumulation in OP9 cells and the 3D adipose equivalents. HW treatment significantly repressed H2O2- or PMA-induced lipid accumulation and IL-6 secretion in OP9 adipocytes and the 3D adipose equivalents. In conclusion, HW showed a possibility of repressing oxidative stress, inflammatory response, and adipogenesis at cellular/tissue levels. It can be used for preventing the development of metabolic disorders amongst obese people.


Author(s):  
JaeSang Ko ◽  
Ji-Young Kim ◽  
Min Kyung Chae ◽  
Eun Jig Lee ◽  
Jin Sook Yoon

We examined endoplasmic reticulum (ER) stress-related gene expression in orbital tissues from patients with Graves’ orbitopathy (GO) and the effects of silencing protein kinase RNA-like endoplasmic reticulum kinase (PERK) in primary orbital fibroblast cultures to demonstrate the therapeutic potential of PERK-modulating agents in GO management. The expression of ER stress related genes in orbital tissue harvested from individuals with or without GO was studied using real-time polymerase chain reaction. The role of PERK in GO pathogenesis was examined through small-interfering RNA (siRNA)-mediated silencing in cultured primary orbital fibroblasts. Intracellular reactive oxygen species (ROS) levels induced in response to cigarette smoke extract (CSE) or hydrogen peroxide were measured using 5-(and 6)-carboxy-20,70-dichlorodihydrofluorescein diacetate staining and flow cytometry. Cells were stained with Oil Red O, and adipogenesis-related transcription factor expression was evaluated through western blotting after adipogenic differentiation. PERK, activating transcription factor 4 (ATF4), and CCAAT-enhancer-binding protein (C/EBP)-homologous protein(CHOP)mRNA levels were significantly higher in GO orbital tissues than in non-GO orbital tissues. PERK silencing inhibited CSE- or hydrogen peroxide-induced ROS generation. After adipogenic differentiation, GO orbital fibroblasts revealed decreased lipid droplets and downregulation of C/EBPα, C/EBPβ, and peroxisome proliferator-activator gamma (PPARγ) in PERK siRNA-transfected cells. The orbital tissues of patients with GO were exposed to chronic ER stress and subsequently exhibited enhanced unfolded protein response (especially through the PERK pathway). PERK silencing reduced oxidative stress and adipogenesis in GO orbital fibroblasts in vitro. Our results imply that PERK-modulating agents can potentially be used to manage GO.


2020 ◽  
Author(s):  
MYUNG HEE KIM ◽  
Dae Hyun Kim ◽  
Su Geun Yang ◽  
Dae Yu Kim

Abstract Background: Oxidative damage in retinal pigmented epithelium (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of TPP-Niacin against the hydrogen peroxide (H2O2)-induced oxidative stress to RPE cells. Methods: The cellular viability, lactate dehydrogenase, reactive oxygen species (ROS), and mitochondrial function were determined in the retinal ARPE-19 cells under the treatment with H2O2 or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-PCR). Results: TPP-Niacin significantly improved cell viability reduction, reduced ROS generation and increased the antioxidant enzymes in H2O2-treated ARPE-19 cells. Mitochondrial dysfunction from H2O2-induced oxidative stress was also significantly diminished by the TPP-Niacin treatment, reduced generation of ROS, an ameliorated reduction of mitochondrial membrane potential (MMP) and an upregulated mitochondrial associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant associated genes (especially, HO-1 and NQO-1). Conclusion: We proved the protective effect of TPP-Niacin against H2O2-induced oxidative stress in RPE cells. TPP-Niacin is believed to have played a protective role against mitochondrial dysfunction by up-regulating antioxidant-related genes such as PGC-1α, NRF2, HO-1 and NQO-1 in RPE cells.


2010 ◽  
Vol 9 (4) ◽  
pp. 569-577 ◽  
Author(s):  
Aurélie Deveau ◽  
Amy E. Piispanen ◽  
Angelyca A. Jackson ◽  
Deborah A. Hogan

ABSTRACT Farnesol, a Candida albicans cell-cell signaling molecule that participates in the control of morphology, has an additional role in protection of the fungus against oxidative stress. In this report, we show that although farnesol induces the accumulation of intracellular reactive oxygen species (ROS), ROS generation is not necessary for the induction of catalase (Cat1)-mediated oxidative-stress resistance. Two antioxidants, α-tocopherol and, to a lesser extent, ascorbic acid effectively reduced intracellular ROS generation by farnesol but did not alter farnesol-induced oxidative-stress resistance. Farnesol inhibits the Ras1-adenylate cyclase (Cyr1) signaling pathway to achieve its effects on morphology under hypha-inducing conditions, and we demonstrate that farnesol induces oxidative-stress resistance by a similar mechanism. Strains lacking either Ras1 or Cyr1 no longer exhibited increased protection against hydrogen peroxide upon preincubation with farnesol. While we also observed the previously reported increase in the phosphorylation level of Hog1, a known regulator of oxidative-stress resistance, in the presence of farnesol, the hog1/hog1 mutant did not differ from wild-type strains in terms of farnesol-induced oxidative-stress resistance. Analysis of Hog1 levels and its phosphorylation states in different mutant backgrounds indicated that mutation of the components of the Ras1-adenylate cyclase pathway was sufficient to cause an increase of Hog1 phosphorylation even in the absence of farnesol or other exogenous sources of oxidative stress. This finding indicates the presence of unknown links between these signaling pathways. Our results suggest that farnesol effects on the Ras-adenylate cyclase cascade are responsible for many of the observed activities of this fungal signaling molecule.


2007 ◽  
Vol 75 (8) ◽  
pp. 4030-4039 ◽  
Author(s):  
Song-Ze Ding ◽  
Yutaka Minohara ◽  
Xue Jun Fan ◽  
Jide Wang ◽  
Victor E. Reyes ◽  
...  

ABSTRACT Helicobacter pylori infection is associated with altered gastric epithelial cell turnover. To evaluate the role of oxidative stress in cell death, gastric epithelial cells were exposed to various strains of H. pylori, inflammatory cytokines, and hydrogen peroxide in the absence or presence of antioxidant agents. Increased intracellular reactive oxygen species (ROS) were detected using a redox-sensitive fluorescent dye, a cytochrome c reduction assay, and measurements of glutathione. Apoptosis was evaluated by detecting DNA fragmentation and caspase activation. Infection with H. pylori or exposure of epithelial cells to hydrogen peroxide resulted in apoptosis and a dose-dependent increase in ROS generation that was enhanced by pretreatment with inflammatory cytokines. Basal levels of ROS were greater in epithelial cells isolated from gastric mucosal biopsy specimens from H. pylori-infected subjects than in cells from uninfected individuals. H. pylori strains bearing the cag pathogenicity island (PAI) induced higher levels of intracellular oxygen metabolites than isogenic cag PAI-deficient mutants. H. pylori infection and hydrogen peroxide exposure resulted in similar patterns of caspase 3 and 8 activation. Antioxidants inhibited both ROS generation and DNA fragmentation by H. pylori. These results indicate that bacterial factors and the host inflammatory response confer oxidative stress to the gastric epithelium during H. pylori infection that may lead to apoptosis.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 252
Author(s):  
Sakan Warinhomhoun ◽  
Chawanphat Muangnoi ◽  
Visarut Buranasudja ◽  
Wanwimon Mekboonsonglarp ◽  
Pornchai Rojsitthisak ◽  
...  

Five compounds including a new bisbibenzyl named dendropachol (1) and four known compounds (2–5) comprising 4,5-dihydroxy-2,3-dimethoxy-9,10-dihydrophenanthrene (2), gigantol (3), moscatilin (4) and 4,5,4′-trihydroxy-3,3′-dimethoxybibenzyl (5) were isolated from a methanolic extract of Dendrobium pachyglossum (Orchidaceae). The chemical structures of the isolated compounds were characterized by spectroscopic methods. Dendropachol (1) was investigated for its protective effects on hydrogen peroxide (H2O2)-induced oxidative stress in HaCaT keratinocytes. Compound 1 showed strong free radical scavenging compared to the positive control. For the cytoprotective effect, compound 1 increased the activities of GPx and CAT and the level of GSH but reduced intracellular reactive oxygen species (ROS) generation and accumulation. In addition, compound 1 significantly diminished the expression of p53, Bax, and cytochrome C proteins, decreased the activities of caspase-3 and caspase-9, and increased Bcl-2 protein. The results suggested that compound 1 exhibited antioxidant activities and protective effects in keratinocytes against oxidative stress induced by H2O2.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Myung Hee Kim ◽  
Do-Hun Kim ◽  
Su Geun Yang ◽  
Dae Yu Kim

Abstract Background Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. Methods The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H2O2 or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR). Results TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H2O2-treated ARPE-19 cells. Mitochondrial dysfunction from the H2O2-induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1). Conclusion We verified the protective effect of TPP-Niacin against H2O2-induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.


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