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Rocha MC, Nucci C, Brito MA, Achkar R, Fontão-Wendel R, Fachini R, Wendel S. INTERFERÊNCIA DO DARATUMUMAB (DARA) NOS TESTES PRÉ-TRANSFUSIONAIS: OPTIMIZAÇÃO DO TRATAMENTO DAS HEMÁCIAS COM DITIOTREITOL (DTT) DE BAIXA CONCENTRAÇÃO PARA REDUÇÃO DO TEMPO DE EXECUÇÃO. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Fontão-Wendel R, Dias L, Achkar R, Scuracchio P, Souto R, Farias C, Pagani FM, Brito MA, Fachini R, Wendel S. MANEJO DE PACIENTES COM REFRATARIEDADE PLAQUETÁRIA: 20 ANOS DE EXPERIÊNCIA. Hematol Transfus Cell Ther 2022. [DOI: 10.1016/j.htct.2022.09.720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Figueira I, Garcia G, Pimpão RC, Terrasso AP, Costa I, Almeida AF, Tavares L, Pais TF, Pinto P, Ventura MR, Filipe A, McDougall GJ, Stewart D, Kim KS, Palmela I, Brites D, Brito MA, Brito C, Santos CN. Correction to: Polyphenols journey through blood-brain barrier towards neuronal protection. Sci Rep 2021; 11:17112. [PMID: 34408218 PMCID: PMC8373959 DOI: 10.1038/s41598-021-96179-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- I Figueira
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - G Garcia
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - R C Pimpão
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - A P Terrasso
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - I Costa
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - A F Almeida
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - L Tavares
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - T F Pais
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156, Oeiras, Portugal
| | - P Pinto
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Escola Superior Agrária, Instituto Politécnico de Santarém, Qta do Galinheiro, Santarém, Portugal
| | - M R Ventura
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal
| | - A Filipe
- Medical Department, Grupo Tecnimede, 2710-089, Sintra, Portugal
| | - G J McDougall
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK
| | - D Stewart
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK.,Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, Scotland, UK.,NIBIO, Norwegian Institute of Bioeconomy Research, Pb 115, NO-1431, Ås, Norway
| | - K S Kim
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street Park 256, Baltimore, MD, 21287, USA
| | - I Palmela
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - D Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - M A Brito
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - C Brito
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - C N Santos
- Instituto de Tecnologia Quı́mica e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal. .,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.
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4
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Figueira I, Garcia G, Pimpão RC, Terrasso AP, Costa I, Almeida AF, Tavares L, Pais TF, Pinto P, Ventura MR, Filipe A, McDougall GJ, Stewart D, Kim KS, Palmela I, Brites D, Brito MA, Brito C, Santos CN. Polyphenols journey through blood-brain barrier towards neuronal protection. Sci Rep 2017; 7:11456. [PMID: 28904352 PMCID: PMC5597593 DOI: 10.1038/s41598-017-11512-6] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 08/08/2017] [Indexed: 01/03/2023] Open
Abstract
Age-related complications such as neurodegenerative disorders are increasing and remain cureless. The possibility of altering the progression or the development of these multifactorial diseases through diet is an emerging and attractive approach with increasing experimental support. We examined the potential of known bioavailable phenolic sulfates, arising from colonic metabolism of berries, to influence hallmarks of neurodegenerative processes. In silico predictions and in vitro transport studies across blood-brain barrier (BBB) endothelial cells, at circulating concentrations, provided evidence for differential transport, likely related to chemical structure. Moreover, endothelial metabolism of these phenolic sulfates produced a plethora of novel chemical entities with further potential bioactivies. Pre-conditioning with phenolic sulfates improved cellular responses to oxidative, excitotoxicity and inflammatory injuries and this attenuation of neuroinflammation was achieved via modulation of NF-κB pathway. Our results support the hypothesis that these small molecules, derived from dietary (poly)phenols may cross the BBB, reach brain cells, modulate microglia-mediated inflammation and exert neuroprotective effects, with potential for alleviation of neurodegenerative diseases.
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Affiliation(s)
- I Figueira
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - G Garcia
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - R C Pimpão
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - A P Terrasso
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - I Costa
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - A F Almeida
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - L Tavares
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - T F Pais
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156, Oeiras, Portugal
| | - P Pinto
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Escola Superior Agrária, Instituto Politécnico de Santarém, Qta do Galinheiro, Santarém, Portugal
| | - M R Ventura
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal
| | - A Filipe
- Medical Department, Grupo Tecnimede, 2710-089, Sintra, Portugal
| | - G J McDougall
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, United Kingdom
| | - D Stewart
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, United Kingdom.,Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, Scotland, United Kingdom.,NIBIO, Norwegian Institute of Bioeconomy Research, Pb 115, NO-1431, Ås, Norway
| | - K S Kim
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street Park 256, Baltimore, MD21287, USA
| | - I Palmela
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - D Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - M A Brito
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - C Brito
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - C N Santos
- Instituto de Tecnologia Quı́mica e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República, EAN, 2781-901, Oeiras, Portugal. .,Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.
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Falcão AS, Bellarosa C, Fernandes A, Brito MA, Silva RFM, Tiribelli C, Brites D. Role of multidrug resistance-associated protein 1 expression in the in vitro susceptibility of rat nerve cell to unconjugated bilirubin. Neuroscience 2007; 144:878-88. [PMID: 17141959 DOI: 10.1016/j.neuroscience.2006.10.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 10/10/2006] [Accepted: 10/14/2006] [Indexed: 12/26/2022]
Abstract
Nerve cell injury by unconjugated bilirubin (UCB) has been implicated in brain damage during neonatal hyperbilirubinemia, particularly in the preterm newborn. Recently, it was shown that UCB is a substrate for the multidrug resistance-associated protein 1 (Mrp1), an ATP-dependent efflux pump, which may decrease UCB intracellular levels. To obtain a further insight into the role of Mrp1 in the increased vulnerability of immature cells to UCB, we evaluated the mRNA and the protein levels of Mrp1 throughout differentiation in primary cultures of rat neurons and astrocytes. Furthermore, in order to provide supportive evidence for the role of Mrp1 in the protection of nerve cells from UCB-induced effects, we evaluated cell susceptibility to UCB when Mrp1 was inhibited with MK571 ((E)-3-[[[3-[2-(7-chloro-2-quinolinyl) ethenyl]phenyl]-[[3-dimethylamino)-3-oxopropyl]thio]methyl]thio]-propanoic acid). The results are the first to demonstrate that Mrp1 is expressed in neurons and that both mRNA and protein levels of Mrp1 increase with cell differentiation. Additionally, inhibition of Mrp1 was associated with an increase in UCB toxic effects, namely cell death, cell dysfunction, and secretion of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, as well as of glutamate. These results point to a novel role of Mrp1 in the susceptibility of premature babies to UCB encephalopathy, and provide a startup point for the development of a new therapeutic strategy.
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Affiliation(s)
- A S Falcão
- Centro de Patogénese Molecular-UBMBE, Faculdade de Farmácia, University of Lisbon, Avenida Professor Gama Pinto, 1649-003 Lisbon, Portugal
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Silva RFM, Falcão AS, Fernandes A, Gordo AC, Brito MA, Brites D. Dissociated primary nerve cell cultures as models for assessment of neurotoxicity. Toxicol Lett 2006; 163:1-9. [PMID: 16257146 DOI: 10.1016/j.toxlet.2005.09.033] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Revised: 09/21/2005] [Accepted: 09/22/2005] [Indexed: 10/25/2022]
Abstract
Exogenous and endogenous neurotoxins may have poisoning effects on living organisms. Neurotoxic signs can result from human intoxication by substances present in natural ecosystems as pollutants, such as inorganic mercury, cadmium, manganese and lead, or by abnormal accumulation of endogenous compounds, as bilirubin. Dissociated primary nerve cell cultures are powerful models that can be used to evaluate the responses of target cells at the cellular and molecular levels to the deleterious effects of neurotoxic substances. Primary cultures of nerve cells are prepared from either fetal (neurons) or 2-day-old (macroglia and microglia) rat brains, cultured with specific media. Cells can then be used to evaluate the neurotoxic effects of a particular substance. By using cells with different days-in-culture it is possible to mimic and evaluate developmental-related modifications. These modifications can comprise morphological changes, cell death by necrosis (release of lactate dehydrogenase, LDH) and apoptosis (nuclear fragmentation), altered neurotransmission (impaired uptake or increased release of glutamate), neuroinflammation (enhanced cytokine production) and the generation of oxidative damage (formation of reactive oxygen species and disruption of glutathione metabolism). Here we describe the methods for nerve cell cultures, as well as some of the procedures that can be used to assess neuronal and glial cytotoxicity induced by different neurotoxins.
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Affiliation(s)
- R F M Silva
- Centro de Patogénese Molecular (UBMBE), Faculdade de Farmácia da Universidade de Lisboa, Av. Forças Armadas, 1600-083 Lisboa, Portugal.
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Abstract
Unconjugated bilirubin increasingly binds to erythrocytes as the bilirubin-to-albumin molar ratio exceeds unity, leading to toxic manifestations that can culminate in cell lysis. Our previous studies showed that bilirubin induces the release of lipids from erythrocyte membranes. In the present work, those studies were extended in order to characterize the alterations of membrane lipid composition and evaluate whether bilirubin leads to a loss of phospholipid asymmetry. To this end, human erythrocytes were incubated with several bilirubin-to-albumin molar ratios (0.5 to 5), and cholesterol as well as the total and the individual classes of phospholipids were determined. To detect erythrocytes with phosphatidylserine at the outer surface, the number of annexin V-positive cells was determined following incubation with bilirubin, fixing its molar ratio to albumin at 3. The results demonstrate profound changes in erythrocyte membrane composition, including modified cholesterol and phospholipid content. The release of membrane cholesterol, as well as of total and individual classes of phospholipids at molar ratios > or = 1, indicates that damage of erythrocytes may occur in severely ill jaundiced neonates. The loss of the inner-located phospholipids, phosphatidylethanolamine and phosphatidylserine, points to a redistribution of phospholipids in the membrane bilayer. This was confirmed by the exposure of phosphatidylserine at the outer cell surface. In conclusion, this study demonstrates that bilirubin induces loss of membrane lipids and externalization of phosphatidylserine in human erythrocytes. These features may facilitate hemolysis and erythrophagocytosis, thus contributing to enhanced bilirubin production and anemia during severe neonatal hyperbilirubinemia.
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Affiliation(s)
- M A Brito
- Centro de Patogénese Molecular, Faculdade de Farmácia, University of Lisbon, Portugal
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Brito MA, Malheiros SV, Meirelles NC, Brites D. Effect of bilirubin on toxicity induced by trifluoperazine, dibucaine and praziquantel to erythrocytes. Life Sci 2001; 69:863-77. [PMID: 11488400 DOI: 10.1016/s0024-3205(01)01171-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Unconjugated bilirubin (UCB), like trifluoperazine (TFP), dibucaine (DBC) and praziquantel (PZQ), induces erythrocyte morphological changes, lysis and lipid exfoliation. In the present study we determined whether TFP, DBC and PZQ toxicity to erythrocytes was potentiated or reverted by UCB. Human erythrocytes were either treated or non-treated with 34.2 micromol/L UCB for 10 min prior to the incubation with toxic concentrations of TFP (0.12 mmol/L), DBC (1.5 mmol/L) or PZQ (3.0 mmol/L), for 1 h (37 degrees C). Studies of toxic effects included morphological analysis of erythrocytes, evaluation of hemoglobin release and loss of membrane lipids. Although UCB has an echinocytogenic effect, its co-incubation with TFP or PZQ did not alter the stomatocytogenic effect of the drug but enhanced DBC-induced stomatocytosis. Cell fusion was a common feature in experiments with DBC. Injurious effect of DBC to erythrocytes was potentiated by UCB as manifested by a marked increase in hemolysis (171%, p<0.05), and in elution of membrane cholesterol (73%, p<0.01) and phospholipids (123%, p<0.01). In opposite, toxic events produced by TFP and PZQ to erythrocytes were not aggravated by UCB. Interestingly, UCB prevented the loss of membrane cholesterol by PZQ (-36%, p<0.01), as well as that of phospholipids by TFP (-28%, p<0.05). These findings indicate that UCB potentiates DBC injury to erythrocytes, while protects membrane lipid elution by PZQ and TFP. Therefore, the relation of the benefits and risks of the administration of DBC to jaundiced patients should be carefully considered.
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Affiliation(s)
- M A Brito
- Centro de Patogénese Molecular, Faculdade de Farmácia, University of Lisbon, Portugal
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Brito MA, Brondino CD, Moura JJ, Brites D. Effects of Bilirubin Molecular Species on Membrane Dynamic Properties of Human Erythrocyte Membranes: A Spin Label Electron Paramagnetic Resonance Spectroscopy Study. Arch Biochem Biophys 2001; 387:57-65. [PMID: 11368184 DOI: 10.1006/abbi.2000.2210] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Unconjugated bilirubin is a neurotoxic pigment that interacts with membrane lipids. In this study we used electron paramagnetic resonance and the spin labels 5-, 7-, 12-, and 16-doxyl-stearic acid (DSA) to evaluate the depth of the hydrocarbon chain at which interaction of bilirubin preferentially occurs. In addition, we used different pH values to determine the molecular species involved. Resealed right-side-out ghosts were incubated (1-60 min) with bilirubin (3.4-42.8 microM) at pH 7.0, 7.4, and 8.0. Alterations of membrane dynamic properties were maximum after 15 min of incubation with 8.6 microM bilirubin at pH 7.4 and were accompanied by a significant release of phospholipids. Interestingly, concentrations of bilirubin up to 42.8 microM and longer incubations resulted in the elution of cholesterol and further increased that of phospholipids while inducing less structural alterations. Variation of the pH values from 8.0 to 7.4 and 7.0, under conditions of maximum perturbation, led to a change from an increased to a diminished polarity sensed by 5-DSA. Conversely, a progressive enhancement in fluidity was reported by 7-DSA, followed by 12- and 16-DSA. These results indicate that bilirubin while enhancing membrane lipid order at C-5 simultaneously has disordering effects at C-7. Furthermore, recovery of membrane dynamics after 15 min of bilirubin exposure along with the release of lipids is compatible with a membrane adaptive response to the insult. In addition, our data provide evidence that uncharged diacid is the species primarily interacting with the membrane as perturbation is favored by acidosis, a condition frequently associated with hyperbilirubinemia in premature and severely ill infants.
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Affiliation(s)
- M A Brito
- Centro de Patogénese Molecular, Faculdade de Farmácia, Universidade de Lisboa, Portugal
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Rodrigues CM, Solá S, Brito MA, Brondino CD, Brites D, Moura JJ. Amyloid beta-peptide disrupts mitochondrial membrane lipid and protein structure: protective role of tauroursodeoxycholate. Biochem Biophys Res Commun 2001; 281:468-74. [PMID: 11181071 DOI: 10.1006/bbrc.2001.4370] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria have been implicated in the cytotoxicity of amyloid beta-peptide (A beta), which accumulates as senile plaques in the brain of Alzheimer's disease patients. Tauroursodeoxycholate (TUDC) modulates cell death, in part, by preventing mitochondrial membrane perturbation. Using electron paramagnetic resonance spectroscopy analysis of isolated mitochondria, we tested the hypothesis that A beta acts locally in mitochondrial membranes to induce oxidative injury, leading to increased membrane permeability and subsequent release of caspase-activating factors. Further, we intended to determine the role of TUDC at preventing A beta-induced mitochondrial membrane dysfunction. The results demonstrate oxidative injury of mitochondrial membranes during exposure to A beta and reveal profound structural changes, including modified membrane lipid polarity and disrupted protein mobility. Cytochrome c is released from the intermembrane space of mitochondria as a consequence of increased membrane permeability. TUDC, but not cyclosporine A, almost completely abrogated A beta-induced perturbation of mitochondrial membrane structure. We conclude that A beta directly induces cytochrome c release from mitochondria through a mechanism that is accompanied by profound effects on mitochondrial membrane redox status, lipid polarity, and protein order. TUDC can directly suppress A beta-induced disruption of the mitochondrial membrane structure, suggesting a neuroprotective role for this bile salt.
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Affiliation(s)
- C M Rodrigues
- Centro de Patogénese Molecular, Faculdade de Farmácia, University of Lisbon, 1600-083 Lisbon, Portugal
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Abstract
Trifluoperazine (TFP) is a potent antipsychotic agent, dibucaine (DBC) is a local anaesthetic and praziquantel (PZQ) is a highly effective agent against schistosomiasis. The present work was conducted to (i) investigate the cytotoxic effects of TFP, DBC and PZQ on human erythrocyte membranes; and (ii) compare the alterations induced by the cationic drugs (TFP and DBC) with those induced by the uncharged compound (PZQ), in an attempt to have a better insight on the pathways of each drug-membrane interaction. The erythrocyte morphological alterations induced by sublytic concentrations of TFP, DBC and PZQ were evaluated by scanning electron microscopy and expressed quantitatively by the morphological index. Haemolysis and release of membrane lipids (phospholipids and cholesterol) produced by selected concentrations of TFP, DBC and PZQ, were compared with those resulting from the corresponding triple concentrations of each drug. Our results showed that the uncharged molecule of PZQ induces the same morphological alterations (stomatocytosis) as the cationic drugs TFP and DBC. Haemolysis was shown to vary with the drug used and to be concentration-dependent, with values approximately 10-fold more elevated for TFP and DBC than for PZQ, which revealed a maximum of 6% haemolysis for the highest concentration tested. Different concentration-response curves were obtained for lipid elution, although the profiles of cholesterol and phospholipids released were similar for all drugs. Nevertheless, at a fixed rate of 50% haemolysis, TFP induced a approximately 2-fold increment in the elution of cholesterol when compared with that produced by DBC (P<0. 05). The different effects induced by TFP, DBC and PZQ on erythrocyte morphology, haemolysis and lipid exfoliation are related to the physical and chemical characteristics of each compound. These results suggest that distinct cell membrane interaction pathways lead to drug-specific mechanisms of cytotoxicity.
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Affiliation(s)
- S V Malheiros
- Department of Biochemistry, Institute of Biology, State University of Campinas, SP, Campinas, Brazil
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Abstract
BACKGROUND Neonatal hyperbilirubinaemia remains one of the most common clinical conditions requiring therapeutic intervention. Nevertheless, reliable indicators of bilirubin toxicity are still missing. This prompted us to investigate (a) the progression of cytotoxic events produced by increasing concentrations of bilirubin; (b) the relevance of the membrane lipid package on bilirubin binding to erythrocytes; and (c) the reliability of chloroform extraction compared with albumin extraction to evaluate erythrocyte-bound bilirubin and cytotoxicity. MATERIALS AND METHODS Morphological alterations, free bilirubin, erythrocyte-bound bilirubin (albumin- and chloroform-extractable), haemolysis and membrane-released lipids, were determined in human erythrocytes at 4 degrees C or 37 degrees C, after 4 h incubation at pH 7.4, with increasing molar ratios of bilirubin to albumin (0.5-5). The reversibility of cytotoxicity by albumin washing was assessed by morphological analysis. RESULTS Decreased free bilirubin, lower erythrocyte-bound bilirubin concentration by albumin extraction (superficial/non-aggregated bilirubin) and higher values by chloroform extraction (deep/aggregated bilirubin) were observed for 37 degrees C vs. 4 degrees C, at molar ratios > 1. Echinocytosis increased with bilirubin concentration and temperature and was not fully reversed by albumin washing. Haemolysis was already significant at a molar ratio of 1, and was enhanced by temperature at molar ratios 3 and 5 (P < 0.01). The loss of membrane lipids was remarkable at molar ratios > or = 0.5, both at 4 degrees C and 37 degrees C (P < 0.01), although correlation with bilirubin concentration was only significant at 37 degrees C (r = 0.971; P < 0.01). CONCLUSIONS These results suggest that increased lipid fluidity and high bilirubin concentrations promote membrane bilirubin translocation and toxicity. They also show that albumin is not able to displace the bilirubin located deeply or aggregated within the membrane, which in turn is removed by chloroform. Accordingly, chloroform-extractable rather than albumin-extractable bilirubin is a more accurate parameter to assess erythrocyte-bound bilirubin during severe hyperbilirubinaemia.
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Affiliation(s)
- M A Brito
- University of Lisbon, Lisbon, Portugal, and; University of Trieste, Trieste, Italy
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13
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Abstract
The long-term histologic effects of CO2 laser resurfacing previously were unknown. Prior investigations have clearly defined the photothermal effect. Collagen shrinkage as a reaction to increased tissue temperature between 60 and 70 degrees C has also been previously described. Twenty-two patients completed a 1-year study in which biopsy specimens from the upper lip were taken preoperatively and 6 weeks, 6 months, and 1 year after CO2 laser resurfacing. Trichrome stains and Verhoeff-van Gieson stains were used to demonstrate tissue collagen and tissue elastin. Neocollagenesis beginning at 6 weeks and progressively increasing at 6 months and 1 year was clearly demonstrated. Neoelastogenesis showed significant increases at 6 months and 1 year. It is hypothesized that the additive effects of initial collagen shrinkage and the long-term effect of neocollagenesis and neoelastogenesis are the significant factors contributing to the long-lasting and excellent results of CO2 laser skin resurfacing.
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Affiliation(s)
- G J Rosenberg
- Division of Plastic Surgery, University of Florida, Gainesville, USA.
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14
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Silva R, Mata LR, Gulbenkian S, Brito MA, Tiribelli C, Brites D. Inhibition of glutamate uptake by unconjugated bilirubin in cultured cortical rat astrocytes: role of concentration and pH. Biochem Biophys Res Commun 1999; 265:67-72. [PMID: 10548492 DOI: 10.1006/bbrc.1999.1646] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The molecular basis of bilirubin toxicity to nerve cell function is still unclear. Since astrocytes are the main transporters of synaptically released glutamate and impaired glutamate uptake results in neuronal death, we investigated the effect of unconjugated bilirubin (UCB) on [(3)H]glutamate uptake in cultured rat astrocytes and the role of bilirubin ionization on toxicity. Astrocytes were incubated for 5-15 min, with UCB concentrations from 17 to 342 microM and UCB/albumin molar ratios of 0.2-3.0, at pH 7.0, 7.4, and 8.0. Exposure of astrocytes for 15 min to 85.5 microM UCB and 28.5 microM albumin resulted in a 63.1% decrease of glutamate uptake (p < 0.01). Interestingly, the effect demonstrated to be correlated with the UCB/albumin molar ratio (r = -0.986, p < 0.01) and a significant decrease was observed for a UCB/albumin molar ratio as low as 0.8. Inhibition of glutamate transport was also pH-dependent as it occurred at 7.4 (p < 0.05) and 8.0 (p < 0.01), but not at 7.0, suggesting that the monoanionic species of UCB accounted for the inhibition. These findings indicate that UCB, and more precisely the monoanionic species, impairs a crucial function of astrocytes such as glutamate transport and support a potential role of astrocyte function in the pathogenesis of UCB-related brain damage (kernicterus).
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Affiliation(s)
- R Silva
- Molecular Pathogenesis Center, Faculty of Pharmacy, University of Lisbon, Lisbon, 1649-19, Portugal
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15
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Martínez-Martínez FJ, Padilla-Martínez II, Brito MA, Geniz ED, Rojas RC, Saavedra JBR, Höpfl H, Tlahuextl M, Contreras R. Three-center intramolecular hydrogen bonding in oxamide derivatives. NMR and X-ray diffraction study. ACTA ACUST UNITED AC 1998. [DOI: 10.1039/a704640e] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Abstract
Morphology and membrane lipid composition of erythrocytes from neonates (jaundiced and healthy) and adults (before and after incubation with bilirubin) were studied. The morphological index, expressing the relative proportions of the different stages of cell distortion, and the membrane cholesterol, phospholipids and cholesterol/phospholipids molar ratio, were determined. In jaundiced neonates a significant increase in the morphological index (P < 0.01) was found. After incubation with bilirubin, adult erythrocytes also showed an increase in the morphological index (P < 0.01). Hemolysis occurred under these conditions, and the red cell ghosts obtained (vesicles) showed a rounded morphology. Higher cholesterol/phospholipid ratio and lower phospholipid content were found in jaundiced neonates compared with healthy babies (P < 0.05) and adults (P < 0.01), as well as in the cells (P < 0.05) and vesicles (P < 0.01) obtained after bilirubin incubation. Bilirubin cytotoxicity may occur in a stepwise manner: deposition of bilirubin in membrane produces echinocytosis, which is followed by disintegration of the lipid bilayer with loss of phospholipids from the membrane.
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Affiliation(s)
- M A Brito
- Centro de Metabolismos e Genética da Faculdade de Farmáeia da Universidade de Lisboa, Portugal
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17
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Scerpella EG, Fatmi AA, Brito MA. Bacterial pericarditis and cardiac tamponade in patients infected with human immunodeficiency virus type 1: case report and review. Clin Infect Dis 1995; 21:1518-9. [PMID: 8749656 DOI: 10.1093/clinids/21.6.1518] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- E G Scerpella
- Department of Medicine, University of Miami School of Medicine, Florida, USA
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