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1.
Iran J Allergy Asthma Immunol ; 22(6): 600-603, 2023 Dec 28.
Article in English | MEDLINE | ID: mdl-38477956

ABSTRACT

Chronic granulomatous disease (CGD) presents with granuloma formation and lethal infections. It is inherited in an autosomal or X-linked recessive pattern. We describe a 10-month-old patient with a fatal secondary HLH as a CGD primary manifestation. We carried out an autopsy and found noncaseating granulomas, an aspergilloma in the lung, and hemophagocytosis. We performed a DHR assay on the patient's mother and grandmother, showing a bimodal pattern conclusive of X-linked CGD. Thus, our definitive diagnosis was CGD complicated by macrophage activation syndrome. CGD is caused by phagocytes' inability to control pathogens, resulting in granulomas. Secondary HLH is a severe complication and could be characterized by the proliferation of macrophages and T lymphocytes and the production of proinflammatory cytokines. The early suspicion of this presentation helps establish a specific treatment, and the study of the carriers helps determine the etiology.


Subject(s)
Granulomatous Disease, Chronic , Lymphohistiocytosis, Hemophagocytic , Macrophage Activation Syndrome , Humans , Infant , Cytokines , Granuloma
2.
Rev. bras. cir. cardiovasc ; 37(4): 501-510, Jul.-Aug. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1394722

ABSTRACT

Abstract Introduction: Endothelial progenitor cells (EPCs) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme activity may affect the vessel wall and have a role in development of aortic aneurysms. EPCs originate from hematopoietic stem cells and can be enumerated from peripheral blood samples by flow cytometry. In this study, we aimed to evaluate the relation of EPC number and NADPH oxidase enzyme activity in the development of thoracic aortic aneurysm (TAA). Methods: Patients with TAA (n=30) and healthy individuals without TAA (control, n=10) were included in our study. Characterization and enumeration of EPC from peripheral blood samples were performed by flow cytometry with panels including markers of EPCs (CD34/CD133/CD309/CD146/CD144). Additionally, NADPH oxidase enzyme activity (capacity) was also measured by the dihydrorhodamine 123 (DHR 123) test. Results: The enumeration of EPC with CD34+/CD146+ marker showed that the number of mean EPC/106 cells was increased in the patient group (41.5/106 cells), but not in the control group (20.50/105 cells) (P<0.01). Additionally, patients with TAA presented significantly lower NADPH oxidase activity by DHR assay than healthy controls (mean stimulation index: 60.40± 7.86 and 75.10±5.21, respectively) (P<0.01). Conclusion: Our results showed that the number of EPCs is significantly higher in aortic aneurysm patients and may have a role in disease progression. The crosstalk between NADPH oxidase enzyme capacity and EPC number may be useful as a parameter to explain the clinical progression of TAA.

3.
J Immunol Methods ; 507: 113308, 2022 08.
Article in English | MEDLINE | ID: mdl-35760097

ABSTRACT

Reactive oxygen species (ROS) and the ability of immune cells to mount an oxidative burst represent an important defense during microbial invasion, but is also recognized for playing a significant role in the progression of inflammatory disorders and disease. Although neutrophils produce the strongest ROS-response, other leukocytes and their cell subsets could play a significant role. Isolation of specific cells for determining their ROS-response can affect their functionality and is laborious or hard to replicate in different settings. We have therefore established a whole blood assay, that only requires 100 µL heparinized blood and utilizes the dihydrorhodamine (DHR) 123 ROS-probe combined with cell surface antibody staining for the specific detection of ROS in several subsets of cells simultaneously using flow cytometry. Although the flow markers chosen are interchangeable with other direct conjugated and cell specific antibodies depending on the research question, we focused on neutrophils (SSChighCD16brightHLA-DRneg/low), eosinophils (SSChighCD16lowHLA-DRlow/negCD193positiveCD125positive) and monocyte subsets (SSCintermediateHLA-DRhighCD14low-positiveCD16negative-positive). As a RBC-lysis reagent we compared BD FACS Lysis Solution to the in-house prepared ammonium-chloride­potassium based ACK Lysis Buffer, that does not fix or permeabilize the immune cells. We find that ACK-lysis of stimulated and stained samples results in superior surface staining, decreased loss of cell subsets, and enhanced resolution of the DHR-signal. Compared to the other cells analyzed in healthy blood donors, neutrophils responded with the highest ROS-response to all tested stimuli (fMLP (low stimuli), E. coli, and PMA (high stimuli)), where eosinophils and the three monocyte subsets also showed an extensive ROS-response when stimulated with E. coli or PMA. Our assay provides the possibility for researchers to examine the ROS-response of specific cell subsets in specific patient groups ex vivo and could also allow the analysis of pharmacological intervention studies targeting ROS, which ultimately can advance the field of immunological research.


Subject(s)
Escherichia coli , Receptors, IgG , Escherichia coli/metabolism , Flow Cytometry/methods , HLA-DR Antigens , Humans , Monocytes , Reactive Oxygen Species/metabolism , Rhodamines
4.
Planta ; 255(3): 69, 2022 Feb 16.
Article in English | MEDLINE | ID: mdl-35174422

ABSTRACT

MAIN CONCLUSION: NBT and HE may be efficiently used for the detection of superoxide, while DCDHF-DA and DHR123 for the detection of peroxynitrite in intact barley root tips, only if PRXs and oxidoreductases are inhibited to avoid false-positive reactions. Strong peroxidase (PRX) and oxidoreductase activities were observed in the barley root tips that were markedly inhibited by NaN3. Rapid and strong nitro-blue tetrazolium chloride (NBT) reduction is associated mainly with the vital functions of root cells but not with superoxide formation. In turn, the inhibition of root surface redox activity by NaN3 strongly reduced the formation of formazan, but its slight accumulation, observed in the root elongation zone, was a result of NADPH oxidase-mediated apoplastic superoxide formation. A longer staining time period with NBT was required for the detection of antimycin A-mediated superoxide formation inside the cells. This antimycin A-induced superoxide was clearly detectable by hydroethidine (HE) after the inhibition of PRXs by NaN3, and it was restricted into the root transition zone. TEMPOL, a superoxide scavenger, strongly inhibited both NBT reduction and HE oxidation in the presence of NaN3. Similarly, the DCDHF-DA and DHR123 oxidation was markedly reduced after the inhibition of apoplastic PRXs by NaN3 and was detectable mainly in the root transition zone. This fluorescence signal was not influenced by the application of pyruvate but was strongly reduced by urea, a peroxynitrite scavenger. The presented results suggest that if the root PRXs and oxidoreductases are inhibited, both NBT and HE detect mainly superoxide, whereas both DCDHF-DA and DHR123 may be efficiently used for the detection of peroxynitrite in intact barley root tips. The inhibition of PRXs and oxidoreductases is crucial for avoiding false-positive reactions in the localization of reactive oxygen species in the intact barley root tip.


Subject(s)
Hordeum , Meristem , Oxidoreductases , Peroxidases , Reactive Oxygen Species , Superoxides
5.
Braz J Cardiovasc Surg ; 37(4): 501-510, 2022 08 16.
Article in English | MEDLINE | ID: mdl-35072395

ABSTRACT

INTRODUCTION: Endothelial progenitor cells (EPCs) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme activity may affect the vessel wall and have a role in development of aortic aneurysms. EPCs originate from hematopoietic stem cells and can be enumerated from peripheral blood samples by flow cytometry. In this study, we aimed to evaluate the relation of EPC number and NADPH oxidase enzyme activity in the development of thoracic aortic aneurysm (TAA). METHODS: Patients with TAA (n=30) and healthy individuals without TAA (control, n=10) were included in our study. Characterization and enumeration of EPC from peripheral blood samples were performed by flow cytometry with panels including markers of EPCs (CD34/CD133/CD309/CD146/CD144). Additionally, NADPH oxidase enzyme activity (capacity) was also measured by the dihydrorhodamine 123 (DHR 123) test. RESULTS: The enumeration of EPC with CD34+/CD146+ marker showed that the number of mean EPC/106 cells was increased in the patient group (41.5/106 cells), but not in the control group (20.50/105 cells) (P<0.01). Additionally, patients with TAA presented significantly lower NADPH oxidase activity by DHR assay than healthy controls (mean stimulation index: 60.40± 7.86 and 75.10±5.21, respectively) (P<0.01). CONCLUSION: Our results showed that the number of EPCs is significantly higher in aortic aneurysm patients and may have a role in disease progression. The crosstalk between NADPH oxidase enzyme capacity and EPC number may be useful as a parameter to explain the clinical progression of TAA.


Subject(s)
Aortic Aneurysm , Endothelial Progenitor Cells , Antigens, CD34 , Biomarkers , CD146 Antigen , Humans , NADPH Oxidases , Stem Cells
6.
Int Arch Allergy Immunol ; 181(7): 540-550, 2020.
Article in English | MEDLINE | ID: mdl-32512560

ABSTRACT

BACKGROUND: Chronic granulomatous disease (CGD) is a rare genetic disorder characterized by failure of phagocytic leukocytes to destroy certain microbes. We present a study on CGD patients enrolled at a single medical center concerning the infectious and noninfectious complications and genetic properties of the disease. METHODS: Icotinamide adenine dinucleotide phosphate oxidase activity and the expression of flavocytochrome b558 were measured by flow cytometry, and clinical outcomes of the patients were listed in relation to the genetic results. RESULTS: The clinical and genetic findings of 32 pediatric cases with CGD from 23 families were enrolled. Pneumonia and anemia were the most common infectious and noninfectious symptoms. Genetic analysis showed that 10 families (43.5%) carried CYBB variants and 13 families (56.5%) have autosomal recessive (AR) CGD, in which 6 families (26%) carried NCF1 variants, 4 (17.4%) carried CYBA variants, and 3 (13%) carried NCF2 variants. The median age of clinical onset was 3.3 and 48 months for patients with X-linked CGD (X-CGD) and AR-CGD, respectively. The onset of symptoms before age 1 year was 94% in X-CGD, 28.5% in AR-CGD, and 12.5% in patients with oxidase residual activity. Moreover, a de novo germline mutation at c.1415delG in CYBB (OMIM#300481) and a novel c.251_263del13bp in CYBA (OMIM#608508) were also investigated. CONCLUSIONS: Ihydrorhodamine-1,2,3 assay could not detect carrier mother in de novo case with CYBB variant. Most X-CGD patients have the onset of symptoms before age 1 year. Additionally, residual oxidase activity in AR-CGD causes a delay in onset, diagnosis, and prophylaxis. The protective role of residual activity is limited while the infection is ongoing and becoming serious.


Subject(s)
Granulomatous Disease, Chronic/diagnosis , Granulomatous Disease, Chronic/genetics , Adolescent , Age of Onset , Child , Child, Preschool , Female , Granulomatous Disease, Chronic/complications , Humans , Infant , Infections/etiology , Male , NADPH Oxidase 2/genetics , NADPH Oxidases/deficiency , NADPH Oxidases/genetics , Retrospective Studies
7.
Rev. chil. pediatr ; 91(1): 19-26, feb. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1092783

ABSTRACT

Resumen: Introducción: La enfermedad granulomatosa crónica (EGC) se caracteriza por una alteración de la función oxidativa de neutrófilos, presentando herencia ligada al cromosoma X (EGC LX) y autosómica recesiva (EGC AR). El ensayo de dihidrorodamina (DHR) es utilizado para el diagnóstico y detección de portadoras, además proporciona información sobre patrones de herencia. Objetivo: Detectar casos de EGC en niños con infecciones recurrentes y evaluar a sus familiares femeninos mediante el ensayo de DHR, para identificar portadoras y obtener información acerca de posibles patrones de herencia. Pacientes y Método: Fueron incluidos 107 pacientes (<18 años de edad) con sospecha clínica de EGC como neumonías, linfadenopatías y abscesos, remitidos por médicos de hospitales públicos, del 2014 al 2017. Además, se incluyeron seis mujeres, familiares de los niños con EGC. A las muestras de los pacientes se aplicó el ensayo DHR, expresando los resultados como índice de estimulación de neutrófilos (IE). Resultados: La mediana de edad de los pacientes fue de 3 años y 62/107 fueron varones. El IE promedio fue 39,7 ± 13,8 y 101/107 niños exhibieron un cambio completo de fluorescencia de DHR. En 2/107 niños no se observó dicho cambio (IE = 1,0), lo cual indica posible EGC LX, y un tercer niño mostró un leve cambio (IE = 4,8), compatible con EGC AR. En 5/6 mujeres se encontró un patrón bimodal, indicando un estado de portadora. Conclusiones: Fueron detectados tres casos de EGC y cinco portadoras mediante el ensayo de DHR, realizado por primera vez en Paraguay. También se obtuvo información sobre los posibles patrones de herencia, EGC LX en dos familias y un caso probable de EGC AR.


Abstract: Introduction: Chronic granulomatous disease (CGD) is characterized by an alteration of the neutrophil oxidative function. Its inheritance patterns are linked to the X chromosome (X-linked CGD) and autosomal recessive (AR CGD). The dihydrorhodamine (DHR) assay is used for the diagnosis and detection of carriers and provides information on inheritance patterns. Objective: To detect CGD cases in chil dren with recurrent infections and to evaluate their female relatives through the DHR assay to iden tify carriers and obtain information about possible inheritance patterns. Patients and Method: 107 patients (<18 years of age) with clinical suspicion of CGD such as pneumonia, lymphadenopathies, and abscesses were included, referred by physicians from public hospitals between 2014 and 2017. Six female relatives of children with CGD were also included. The DHR assay was performed on all patient samples and the results were expressed as neutrophils stimulation index (SI). Results: The median age of patients was 3 years and 62/107 of them were male. The average SI was 39.7±13.8 and a complete shift of DHR was found in 101/107 children. In 2/107 children, no DHR shift was observed (SI=1.0) indicating possible X-linked CGD, and a third child showed a slight DHR shift (SI=4.8) compatible with AR CGD. 5/6 female relatives presented a bimodal pattern, showing a carrier status. Conclusions: Three cases of CGD and five female carriers were detected through the DHR assay, being the first time that this technique was used in Paraguay. Information on the most likely inheri tance patterns, two X-linked CGD, and one AR CGD case was also obtained.


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Rhodamines/blood , Granulomatous Disease, Chronic/diagnosis , Biomarkers/blood , Inheritance Patterns , Flow Cytometry , Granulomatous Disease, Chronic/genetics , Granulomatous Disease, Chronic/blood
8.
J Clin Immunol ; 39(8): 762-775, 2019 11.
Article in English | MEDLINE | ID: mdl-31456102

ABSTRACT

PURPOSE: Chronic granulomatous disease (CGD) is the most common phagocyte defect disease. Here, we describe 114 CGD patients in our center and report a rare female infant with XL-CGD to provide a better understanding of diagnosis, treatment, and prenatal diagnosis of CGD. METHOD: Patients were diagnosed by DHR-1,2,3 flow cytometry assays and gene analysis. X chromosome inactivation analysis and gp91phox protein test were used for a female infant with XL-CGD. RESULTS: XL-CGD accounts for the majority of cases in China and results in higher susceptibility to some infections than AR-CGD. The DHR assay can help diagnose CGD quickly, and atypical results should be combined with clinical manifestations, genetic analysis, and regular follow-up. For prenatal diagnosis, both gDNA and cDNA genotypes of amniotic fluid cells should be identified, and cord blood DHR assays should be performed to identify female XL-CGD patients.


Subject(s)
Genetic Testing/statistics & numerical data , Granulomatous Disease, Chronic/diagnosis , Prenatal Diagnosis/statistics & numerical data , X Chromosome Inactivation/genetics , Amniotic Fluid/cytology , Child , Child, Preschool , China/epidemiology , Female , Flow Cytometry/statistics & numerical data , Follow-Up Studies , Granulomatous Disease, Chronic/epidemiology , Granulomatous Disease, Chronic/genetics , Humans , Infant , Male , NADPH Oxidase 2/genetics , Rhodamines/chemistry
9.
Blood Res ; 53(4): 299-306, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30588467

ABSTRACT

BACKGROUND: IgG-mediated anaphylaxis occurs after infusion of certain monoclonal antibody-based therapeutics. New in vitro tests are urgently needed to diagnose such reactions. We investigated whether allergens trigger neutrophil oxidative burst (OB) and if neutrophil OB occurs due to allergen-specific IgG (sIgG). METHODS: Neutrophil OB was measured by dihydrorhodamine 123 flow cytometry using a leukocyte suspension spiked with a very small patch of the allergen crude extract, Dermatophagoides farinae (Der f). The mean fluorescence intensity ratio of stimulated to unstimulated samples was calculated as the neutrophil oxidative index (NOI). RESULTS: The Der f-specific NOI (Der f-sNOI) showed a time-dependent increase after Der f extract addition. At 15 min activation, higher Der f-sIgG levels were associated with lower Der f-sNOI values in 31 subjects (P<0.05). This inverse relationship occurs due to the initial blocking effect of free Der f-sIgG. Additionally, neutrophil OB was nearly absent (Der f-sNOI of -1) in two cases: a subject with undetectable Der f-sIgG levels and washed leukocyte suspensions deprived of Der f-sIgG. CONCLUSION: Allergens can trigger neutrophil OB via preexisting allergen-sIgG. Neutrophil OB can be easily measured in a leukocyte suspension spiked with the allergen. This assay can be used to diagnose IgG-mediated anaphylaxis.

10.
Blood Research ; : 299-306, 2018.
Article in English | WPRIM (Western Pacific) | ID: wpr-718480

ABSTRACT

BACKGROUND: IgG-mediated anaphylaxis occurs after infusion of certain monoclonal antibody-based therapeutics. New in vitro tests are urgently needed to diagnose such reactions. We investigated whether allergens trigger neutrophil oxidative burst (OB) and if neutrophil OB occurs due to allergen-specific IgG (sIgG). METHODS: Neutrophil OB was measured by dihydrorhodamine 123 flow cytometry using a leukocyte suspension spiked with a very small patch of the allergen crude extract, Dermatophagoides farinae (Der f). The mean fluorescence intensity ratio of stimulated to unstimulated samples was calculated as the neutrophil oxidative index (NOI). RESULTS: The Der f-specific NOI (Der f-sNOI) showed a time-dependent increase after Der f extract addition. At 15 min activation, higher Der f-sIgG levels were associated with lower Der f-sNOI values in 31 subjects (P < 0.05). This inverse relationship occurs due to the initial blocking effect of free Der f-sIgG. Additionally, neutrophil OB was nearly absent (Der f-sNOI of −1) in two cases: a subject with undetectable Der f-sIgG levels and washed leukocyte suspensions deprived of Der f-sIgG. CONCLUSION: Allergens can trigger neutrophil OB via preexisting allergen-sIgG. Neutrophil OB can be easily measured in a leukocyte suspension spiked with the allergen. This assay can be used to diagnose IgG-mediated anaphylaxis.


Subject(s)
Allergens , Anaphylaxis , Dermatophagoides farinae , Flow Cytometry , Fluorescence , Immunoglobulin G , In Vitro Techniques , Leukocytes , Neutrophils , Respiratory Burst , Suspensions
11.
Biochem Pharmacol ; 143: 53-64, 2017 11 01.
Article in English | MEDLINE | ID: mdl-28728917

ABSTRACT

P-glycoprotein (P-gp), an ATP-dependent efflux pump, is linked to the development of multidrug resistance in cancer cells. However, the drug-binding sites and translocation pathways of this transporter are not yet well-characterized. We recently demonstrated the important role of tyrosine residues in regulating P-gp ATP hydrolysis via hydrogen bond formations with high affinity modulators. Since tyrosine is both a hydrogen bond donor and acceptor, and non-covalent interactions are key in drug transport, in this study we investigated the global effect of enrichment of tyrosine residues in the drug-binding pocket on the drug binding and transport function of P-gp. By employing computational analysis, 15 conserved residues in the drug-binding pocket of human P-gp that interact with substrates were identified and then substituted with tyrosine, including 11 phenylalanine (F72, F303, F314, F336, F732, F759, F770, F938, F942, F983, F994), two leucine (L339, L975), one isoleucine (I306), and one methionine (M949). Characterization of the tyrosine-rich P-gp mutant in HeLa cells demonstrated that this major alteration in the drug-binding pocket by introducing fifteen additional tyrosine residues is well tolerated and has no measurable effect on total or cell surface expression of this mutant. Although the tyrosine-enriched mutant P-gp could transport small to moderate size (<1000 Daltons) fluorescent substrates, its ability to transport large (>1000 Daltons) substrates such as NBD-cyclosporine A, Bodipy-paclitaxel and Bodipy-vinblastine was significantly decreased. This was further supported by the physico-chemical characterization of seventeen tested substrates, which revealed a negative correlation between drug transport and molecular size for the tyrosine-enriched P-gp mutant.


Subject(s)
Amino Acid Substitution , Antineoplastic Agents , Drug Design , Tyrosine/genetics , ATP Binding Cassette Transporter, Subfamily B/chemistry , ATP Binding Cassette Transporter, Subfamily B/genetics , ATP Binding Cassette Transporter, Subfamily B/metabolism , Adenosine Triphosphate/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Binding Sites , Biological Transport , Conserved Sequence , Flow Cytometry , HeLa Cells , Humans , Hydrogen Bonding , Hydrolysis , Ligands , Mutation , Species Specificity , Substrate Specificity
12.
J Clin Immunol ; 37(2): 109-112, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28035544

ABSTRACT

Chronic granulomatous disease (CGD) is an inheritable and genetically heterogeneous disease resulting from mutations in different subcomponents of the NADPH oxidase system. Mutations in the NCF2 gene account for <5% of all cases of CGD. We analyzed the clinical and laboratory findings of CGD with mutations in the NCF2 gene from amongst our cohort of CGD patients. A homozygous mutation (c.835_836delAC, p.T279fsX294), a deletion in NCF2 gene was found in two cases. In the third case, two heterozygous mutations were detected, IVS13-2A>T on one allele and c.1099C>T (p.) on the other allele. The mother of this child was a carrier for the IVS13-2A>T mutation. All three cases had colitis, and it was the initial symptom in two patients. One of the patients also developed a lung abscess due to Nocardia cyriacigeorgica.


Subject(s)
Genetic Association Studies , Genetic Predisposition to Disease , Granulomatous Disease, Chronic/diagnosis , Granulomatous Disease, Chronic/genetics , Mutation , NADPH Oxidases/genetics , Child, Preschool , DNA Mutational Analysis , Family , Genes, Recessive , Genotype , Humans , Infant , Male , Neutrophils/immunology , Neutrophils/metabolism , Radiography, Thoracic , Tomography, X-Ray Computed
13.
Acta Pharm Sin B ; 5(1): 8-24, 2015 Jan.
Article in English | MEDLINE | ID: mdl-26579420

ABSTRACT

Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage.

14.
Free Radic Biol Med ; 89: 1165-75, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26546694

ABSTRACT

Nitroxides are promising compounds for prevention of undesired protein modifications. The aim of this study was to compare the efficiency of 11 nitroxides, derivatives of 2,2,6,6-tetramethylpiperidine-1-oxide (TEMPO) and 2,2,5,5-tetramethylpirrolidine-1-oxyl (PROXYL) in prevention of nitration and oxidation of model compounds and human serum albumin (HSA). Most nitroxides were very efficient in preventing loss of fluorescein fluorescence induced by peroxynitrite (PN) (IC50 in the nanomolar range) and preventing HSA nitration. The loss of fluorescein fluorescence was demonstrated to be due to nitration. Nitroxides were more effective in prevention nitration than oxidation reactions. They showed a concentration window for preventing dihydrorhodamine (DHR) 123 oxidation but exerted a prooxidant effect at both high and low concentrations. No prooxidant effect of nitroxides was seen in prevention of DHR123 oxidation induced by SIN-1. In all essays hydrophobic nitroxides (especially 4-nonylamido-TEMPO and 3-carbamolyl-dehydroPROXYL) showed the lowest efficiency. An exception was the prevention of thiol group oxidation by PN and SIN-1 where hydrophobic nitroxides were the most effective, apparently due to binding to the protein. Nitroxides showed low toxicity to MCF-7 cells. Most nitroxides, except for the most hydrophobic ones, protected cells from the cytotoxic action of SIN-1 and SIN-1-induced protein nitration. These results point to potential usefulness of nitroxides for prevention of PN-induced oxidation and, especially, nitration.


Subject(s)
Apoptosis/drug effects , Nitrates/metabolism , Nitrogen Oxides/pharmacology , Peroxynitrous Acid/pharmacology , Reactive Nitrogen Species/metabolism , Reactive Oxygen Species/metabolism , Humans , MCF-7 Cells , Oxidation-Reduction , Sulfhydryl Compounds/chemistry , Tandem Mass Spectrometry
15.
Biochem Biophys Res Commun ; 443(2): 556-61, 2014 Jan 10.
Article in English | MEDLINE | ID: mdl-24326071

ABSTRACT

Neutrophil extracellular traps (NETs) are composed of extracellular DNA fibers with antimicrobial peptides that capture and kill microbes. NETs play a critical role in innate host defense and in autoimmune and inflammatory diseases. While the mechanism of NET formation remains unclear, reactive oxygen species (ROS) produced via activation of NADPH oxidase (Nox) are known to be an important requirement. In this study, we investigated the effect of uric acid (UA) on NET formation. UA, a well-known ROS scavenger, was found to suppress Nox-dependent ROS release in a dose-dependent manner. Low concentrations of UA significantly inhibited Nox-dependent NET formation. However, high concentrations of UA unexpectedly induced, rather than inhibited, NET formation. NETs were directly induced by UA alone in a Nox-independent manner, as revealed by experiments using control neutrophils treated with ROS inhibitors or neutrophils of patients with chronic granulomatous disease who have a congenital defect in ROS production. Furthermore, we found that UA-induced NET formation was partially mediated by NF-κB activation. Our study is the first to demonstrate the novel function of UA in NET formation and may provide insight into the management of patients with hyperuricemia.


Subject(s)
Extracellular Fluid/immunology , Granulomatous Disease, Chronic/immunology , NADPH Oxidases/immunology , Neutrophil Activation/immunology , Neutrophils/immunology , Reactive Oxygen Species/immunology , Uric Acid/pharmacology , Adult , Extracellular Fluid/drug effects , Female , Granulomatous Disease, Chronic/pathology , Humans , Male , Neutrophil Activation/drug effects , Neutrophils/drug effects , Neutrophils/pathology , Young Adult
16.
Autophagy ; 10(12): 2362-78, 2014.
Article in English | MEDLINE | ID: mdl-25551567

ABSTRACT

We investigated the role of autophagy, a controlled cellular self-digestion process, in regulating survival of neurons exposed to atypical antipsychotic olanzapine. Olanzapine induced autophagy in human SH-SY5Y neuronal cell line, as confirmed by the increase in autophagic flux and presence of autophagic vesicles, fusion of autophagosomes with lysosomes, and increase in the expression of autophagy-related (ATG) genes ATG4B, ATG5, and ATG7. The production of reactive oxygen species, but not modulation of the main autophagy repressor MTOR or its upstream regulators AMP-activated protein kinase and AKT1, was responsible for olanzapine-triggered autophagy. Olanzapine-mediated oxidative stress also induced mitochondrial depolarization and damage, and the autophagic clearance of dysfunctional mitochondria was confirmed by electron microscopy, colocalization of autophagosome-associated MAP1LC3B (LC3B henceforth) and mitochondria, and mitochondrial association with the autophagic cargo receptor SQSTM1/p62. While olanzapine-triggered mitochondrial damage was not overtly toxic to SH-SY5Y cells, their death was readily initiated upon the inhibition of autophagy with pharmacological inhibitors, RNA interference knockdown of BECN1 and LC3B, or biological free radical nitric oxide. The treatment of mice with olanzapine for 14 d increased the brain levels of autophagosome-associated LC3B-II and mRNA encoding Atg4b, Atg5, Atg7, Atg12, Gabarap, and Becn1. The administration of the autophagy inhibitor chloroquine significantly increased the expression of proapoptotic genes (Trp53, Bax, Bak1, Pmaip1, Bcl2l11, Cdkn1a, and Cdkn1b) and DNA fragmentation in the frontal brain region of olanzapine-exposed animals. These data indicate that olanzapine-triggered autophagy protects neurons from otherwise fatal mitochondrial damage, and that inhibition of autophagy might unmask the neurotoxic action of the drug.


Subject(s)
Antipsychotic Agents/pharmacology , Autophagy/drug effects , Benzodiazepines/pharmacology , Lysosomes/drug effects , Mitochondria/drug effects , Neurons/drug effects , AMP-Activated Protein Kinases/metabolism , Animals , Apoptosis/drug effects , Cell Line , Humans , Mice , Neurons/cytology , Olanzapine , Reactive Oxygen Species/metabolism
17.
Chem Biol Interact ; 206(2): 289-301, 2013 Nov 25.
Article in English | MEDLINE | ID: mdl-24125835

ABSTRACT

It is known that flavonoids possess, among others, antioxidant and antitumoral properties that depend on their molecular structure. The central objective if this study was to investigate the potential antioxidant and antiproliferative properties of the flavonol morin and its new oxovanadium(IV) complex (VOmor) that was synthesized in order to modify the morin chemical structure. Two osteoblast (UMR106 and MC3T3E1), two breast tumor (T47D and SKBR3) and breast epithelial cell lines in culture were used for the antitumoral determinations. Additionally, a comparative study of their antioxidant capacities using different radicals (DPPH, ABTS(+), OH, O2(-), ROO) was performed. Selected mechanisms of action were studied using the breast cancer cell lines. Results obtained show that morin and its complex behaved as good antioxidant agents for some of the radicals and that the complexation improved the behavior with respect to OH and O2(-) radicals being morin more effective as ROO scavenger. A considerable variation in sensitivity was observed in the breast cancer cells but non-specificity was found for the treatment of osteosarcoma. Moreover, the compounds did not affect the normal proliferation of the breast epithelial mammal cells. The mechanistic studies demonstrated that the complex did not generate reactive oxygen species in the cells (confirming the in vitro studies) and did not produce any damage of DNA. The plasmatic membrane was observed to be damaged only in the SKBR3 cell line. In contrast, the perturbation of the mitochondrial membrane potential and the activation of caspase 3/7 for the breast tumor cells revealed an apoptotic cell death process. All these results collectively suggested that VOmor complex could serve as promising pharmacologically active substance against breast cancer treatment.


Subject(s)
Antineoplastic Agents/chemistry , Antioxidants/chemistry , Coordination Complexes/chemistry , Flavonoids/chemistry , Vanadium/chemistry , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , Caspase 3/metabolism , Caspase 7/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Coordination Complexes/chemical synthesis , Electron Spin Resonance Spectroscopy , Humans , Mice , Rats , Reactive Oxygen Species/metabolism
18.
Toxicol In Vitro ; 27(8): 2305-15, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24134853

ABSTRACT

Chalcones are naturally occurring compounds with diverse pharmacological activities. Chalcones derive from the common structure: 1,3-diphenylpropenone. The present study aims to better understand the mechanistic pathways triggering chalcones anticancer effects and providing evidences that minor structural difference could lead to important difference in mechanistic effect. We selected two recently investigated chalcones (A and B) and investigated them on glioblastoma cell lines. It was found that chalcone A induced an apoptotic process (type I PCD), via the activation of caspase-3, -8 and -9. Chalcone A also increased CDK1/cyclin B ratios and decreased the mitochondrial transmembrane potential (ΔΨm). Chalcone B induced an autophagic cell death process (type II PCD), ROS-related but independent of both caspases and protein synthesis. Both chalcones increased Bax/Bcl2 ratios and decreased Ki67 and CD71 antigen expressions. The present investigation reveals that despite the close structure of chalcones A and B, significant differences in mechanism of effect were found.


Subject(s)
Antineoplastic Agents/pharmacology , Chalcones/pharmacology , Catalase/genetics , Cell Cycle/drug effects , Cell Death/drug effects , Cell Death/physiology , Cell Line, Tumor , Glutathione Peroxidase/genetics , Humans , Malondialdehyde/metabolism , Mitotic Index , Reactive Oxygen Species/metabolism , Glutathione Peroxidase GPX1
19.
J Allergy Clin Immunol ; 132(5): 1156-1163.e5, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23910690

ABSTRACT

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder of phagocytes resulting in impaired killing of bacteria and fungi. A mutation in one of the 4 genes encoding the components p22(phox), p47(phox), p67(phox), and p40(phox) of the leukocyte nicotinamide dinucleotide phosphate reduced (NADPH) oxidase leads to autosomal recessive (AR) CGD. A mutation in the CYBB gene encoding gp91(phox) leads to X-linked recessive CGD. OBJECTIVE: The aim of this study is to show the correlation between clinical, functional, and genetic data of patients with CGD from Turkey. METHODS: We report here the results of 89 patients with CGD from 73 Turkish families in a multicenter study. RESULTS: Most of the families (55%) have an AR genotype, and 38% have an X-linked genotype; patients from 5 families with a suspected AR genotype (7%) were not fully characterized. We compared patients with CGD according to the severity of NADPH oxidase deficiency of neutrophils. Patients with A22(0), A67(0) or X91(0) phenotypes with a stimulation index of 1.5 or less have early clinical presentation and younger age at diagnosis (mean, 3.2 years). However, in p47(phox)-deficient cases and in 5 other AR cases with high residual oxidase activity (stimulation index ≥ 3), later and less severe clinical presentation and older age at diagnosis (mean, 7.1 years) were found. Pulmonary involvement was the most common clinical feature, followed by lymphadenitis and abscesses. CONCLUSION: Later and less severe clinical presentation and older age at diagnosis are related to the residual NADPH oxidase activity of neutrophils and not to the mode of inheritance. CGD caused by A22(0) and A67(0) subtypes manifests as severe as the X91(0) subtype.


Subject(s)
Granulomatous Disease, Chronic/diagnosis , Granulomatous Disease, Chronic/genetics , Cause of Death , Child, Preschool , Enzyme Activation , Female , Granulomatous Disease, Chronic/complications , Granulomatous Disease, Chronic/mortality , Humans , Incidence , Infections/etiology , Male , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Neutrophils/metabolism , Sequence Analysis, DNA
20.
Free Radic Biol Med ; 53(12): 2308-17, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-23089227

ABSTRACT

Chloride anion is critical for hypochlorous acid (HOCl) production and microbial killing in neutrophil phagosomes. However, the molecular mechanism by which this anion is transported to the organelle is poorly understood. In this report, membrane-enclosed and functionally active phagosomes were isolated from human neutrophils by using opsonized paramagnetic latex microspheres and a rapid magnetic separation method. The phagosomes recovered were highly enriched for specific protein markers associated with this organelle such as lysosomal-associated membrane protein-1, myeloperoxidase (MPO), lactoferrin, and NADPH oxidase. When FITC-dextran was included in the phagocytosis medium, the majority of the isolated phagosomes retained the fluorescent label after isolation, indicative of intact membrane structure. Flow cytometric measurement of acridine orange, a fluorescent pH indicator, in the purified phagosomes demonstrated that the organelle in its isolated state was capable of transporting protons to the phagosomal lumen via the vacuolar-type ATPase proton pump (V-ATPase). When NADPH was supplied, the isolated phagosomes constitutively oxidized dihydrorhodamine 123, indicating their ability to produce hydrogen peroxide. The preparations also showed a robust production of HOCl within the phagosomal lumen when assayed with the HOCl-specific fluorescent probe R19-S by flow cytometry. MPO-mediated iodination of the proteins covalently conjugated to the phagocytosed beads was quantitatively measured. Phagosomal uptake of iodide and protein iodination were significantly blocked by chloride channel inhibitors, including CFTRinh-172 and NPPB. Further experiments determined that the V-ATPase-driving proton flux into the isolated phagosomes required chloride cotransport, and the cAMP-activated CFTR chloride channel was a major contributor to the chloride transport. Taken together, the data suggest that the phagosomal preparation described herein retains ion transport properties, and multiple chloride channels including CFTR are responsible for chloride supply to neutrophil phagosomes.


Subject(s)
Chlorides/metabolism , Neutrophils/metabolism , Phagosomes/metabolism , Biological Transport , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Halogenation , Humans , Hypochlorous Acid/metabolism , NADPH Oxidases/metabolism , Oxidation-Reduction , Peroxidase/metabolism , Vacuolar Proton-Translocating ATPases/metabolism
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