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Dias da Rocha MA, Saint Aroman M, Mengeaud V, Carballido F, Doat G, Coutinho A, Bagatin E. Unveiling the Nuances of Adult Female Acne: A Comprehensive Exploration of Epidemiology, Treatment Modalities, Dermocosmetics, and the Menopausal Influence. Int J Womens Health 2024; 16:663-678. [PMID: 38650835 PMCID: PMC11034510 DOI: 10.2147/ijwh.s431523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/15/2024] [Indexed: 04/25/2024] Open
Abstract
Previously considered a skin disease exclusively affecting adolescents, characterized by inflammatory and non-inflammatory skin lesions, acne vulgaris is now increasingly observed in adult life, including post-menopause. Today, adult female acne (AFA) is a common chronic inflammatory disease of the pilosebaceous unit, with polymorphic lesions presenting as open or closed comedones, papules, pustules, and even nodules or cysts, often with the presence of sequelae. AFA may persist from adolescence or manifest de novo in adulthood. Its etiology is multifactorial, involving genetic, hormonal, dietary, and environmental factors, yet still incompletely understood. Increased sebum production, keratinocyte hyper-proliferation, inflammation, and reduced diversity of Cutibacterium acnes strains are the underlying disease mechanisms. During menopausal transition, a relative increase in androgen levels occurs, just as estrogens begin to decline, which can manifest itself as acne. Whereas most AFA exhibit few acne lesions with normo-androgenic serum levels, baseline investigations including androgen testing panel enable associated comorbidities to be eliminated, such as polycystic ovarian syndrome, congenital adrenal hyperplasia, or tumors. Another interesting feature is AFA's impact on quality of life, which is greater than in adolescents, being similar to other chronic diseases like asthma. The therapeutic approach to AFA depends on its severity and associated features. This review investigates the intricate facets of AFA, with a specific focus on incidence rates, treatment modalities, and the curious impact of menopause. Utilizing insights from contemporary literature and scientific discussions, this article seeks to advance our understanding of AFA, offering new perspectives to shape clinical practices and improve patient outcomes.
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Affiliation(s)
| | - Markéta Saint Aroman
- Corporate Medical Direction Dermocosmetics Care & Personal Care, Pierre Fabre, Toulouse, France
| | - Valérie Mengeaud
- Laboratoires Dermatologiques Ducray, Pierre Fabre Dermo-Cosmétique, Lavaur, France
| | - Fabienne Carballido
- Laboratoires Dermatologiques A-Derma, Pierre Fabre Dermo-Cosmétique, Lavaur, France
| | - Gautier Doat
- Laboratoires Dermatologiques Avène, Pierre Fabre Dermo-Cosmétique, Lavaur, France
| | - Ana Coutinho
- Laboratorios Pierre Fabre do Brasil LTDA, Rio de Janeiro, Brazil
| | - Edileia Bagatin
- Department of Dermatology, Universidade Federal de São Paulo, São Paulo, Brazil
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Lopes-Nunes J, Simões P, Moreira D, Leandro K, Nobre RJ, Pereira de Almeida L, Campello MPC, Oliveira MC, Paulo A, Coutinho A, Melo AM, Tomaz C, Cruz C. RNA-based liposomes for oral cancer: From biophysical characterization to biological evaluation. Int J Biol Macromol 2024; 259:129157. [PMID: 38199539 DOI: 10.1016/j.ijbiomac.2023.129157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024]
Abstract
Oral cancer incidence and mortality are increasing over time. The most common therapies for oral cancers are surgery and radiotherapy, either used alone or combined, and immunotherapy can be also an option. Although there are several therapeutic options, none of them are completely effective, and in addition, there are numerous associated side effects. To overcome these limitations, researchers have been trying to reduce these drawbacks by using drug delivery systems that carry drugs for specific delivery to cancer cells. For that purpose, RNA-coated liposomes to selectively deliver the ligands C8 (acridine orange derivative) and dexamethasone to oral cancer cells were produced, characterized, and biologically evaluated. Firstly, the RNA structure and binding interaction with ligands (C8 and dexamethasone) were evaluated by circular dichroism (CD), thermal difference spectroscopy (TDS), nuclear magnetic resonance (NMR) and fluorescence titrations. The biophysical assays evidenced the formation of an RNA hairpin and duplex structure. Moreover, steady-state and time-resolved fluorescence intensity and anisotropy experiments show that C8 forms a complex with RNA and adopts an open conformation upon RNA binding. Then, RNA-coated liposomes were characterized by dynamic light scattering, and diameters near 160 nm were observed. Time-resolved anisotropy measurements of C8 loaded in RNA-functionalized liposomes indicate the co-existence of free C8 in solution (inside the liposome) and C8 bound to RNA at the external liposome surface. The RNA-functionalized liposomes loaded with C8 or dexamethasone mediated a significant reduction in the cell viability of malignant UPCI-SCC-154 cells while maintaining viable non-malignant NHDF cells. Additionally, the liposomes were able to internalize the cells, with higher uptake by the malignant cell line. Overall, the results obtained in this work can contribute to the development of new drug delivery systems based on RNA-coated liposomes.
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Affiliation(s)
- Jéssica Lopes-Nunes
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Pedro Simões
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - David Moreira
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Kevin Leandro
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Rui Jorge Nobre
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal; Viral Vectors for Gene Transfer Core Facility, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, 3030-789 16 Coimbra, Portugal
| | - Luís Pereira de Almeida
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal; CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal; Viral Vectors for Gene Transfer Core Facility, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal
| | - Maria Paula Cabral Campello
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
| | - Maria Cristina Oliveira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
| | - António Paulo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal; Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
| | - Ana Coutinho
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Ana M Melo
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Cândida Tomaz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal; Departamento de Química, Universidade da Beira Interior, Rua Marquês de Ávila e Bolama, 6201-001 Covilhã, Portugal
| | - Carla Cruz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal; Departamento de Química, Universidade da Beira Interior, Rua Marquês de Ávila e Bolama, 6201-001 Covilhã, Portugal.
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3
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Morán‐Lalangui M, Coutinho A, Prieto M, Fedorov A, Pérez‐Gil J, Loura LMS, García‐Álvarez B. Exploring protein-protein interactions and oligomerization state of pulmonary surfactant protein C (SP-C) through FRET and fluorescence self-quenching. Protein Sci 2024; 33:e4835. [PMID: 37984447 PMCID: PMC10731621 DOI: 10.1002/pro.4835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023]
Abstract
Pulmonary surfactant (PS) is a lipid-protein complex that forms films reducing surface tension at the alveolar air-liquid interface. Surfactant protein C (SP-C) plays a key role in rearranging the lipids at the PS surface layers during breathing. The N-terminal segment of SP-C, a lipopeptide of 35 amino acids, contains two palmitoylated cysteines, which affect the stability and structure of the molecule. The C-terminal region comprises a transmembrane α-helix that contains a ALLMG motif, supposedly analogous to a well-studied dimerization motif in glycophorin A. Previous studies have demonstrated the potential interaction between SP-C molecules using approaches such as Bimolecular Complementation assays or computational simulations. In this work, the oligomerization state of SP-C in membrane systems has been studied using fluorescence spectroscopy techniques. We have performed self-quenching and FRET assays to analyze dimerization of native palmitoylated SP-C and a non-palmitoylated recombinant version of SP-C (rSP-C) using fluorescently labeled versions of either protein reconstituted in different lipid systems mimicking pulmonary surfactant environments. Our results reveal that doubly palmitoylated native SP-C remains primarily monomeric. In contrast, non-palmitoylated recombinant SP-C exhibits dimerization, potentiated at high concentrations, especially in membranes with lipid phase separation. Therefore, palmitoylation could play a crucial role in stabilizing the monomeric α-helical conformation of SP-C. Depalmitoylation, high protein densities as a consequence of membrane compartmentalization, and other factors may all lead to the formation of protein dimers and higher-order oligomers, which could have functional implications under certain pathological conditions and contribute to membrane transformations associated with surfactant metabolism and alveolar homeostasis.
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Affiliation(s)
- Mishelle Morán‐Lalangui
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Ana Coutinho
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
- Department of Chemistry and BiochemistryFaculty of Sciences, University of LisbonLisbonPortugal
| | - Manuel Prieto
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Alexander Fedorov
- iBB Institute for Bioengineering and Bioscience, IST, Universidade de LisboaLisbonPortugal
- Associate Lab i4HB, Institute for Health and Bioeconomy at IST, Universidade de LisboaLisbonPortugal
| | - Jesús Pérez‐Gil
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
| | - Luís M. S. Loura
- Department of Chemistry, Coimbra Chemistry Centre, Institute of Molecular Sciences (CQC‐IMS)University of CoimbraCoimbraPortugal
- CNC Centre for Neuroscience and Cell Biology, University of CoimbraCoimbraPortugal
- Faculty of PharmacyUniversity of CoimbraCoimbraPortugal
| | - Begoña García‐Álvarez
- Department of Biochemistry and Molecular BiologyFaculty of Biology, Complutense UniversityMadridSpain
- Research Institute “Hospital 12 de Octubre (imas12)”MadridSpain
- Department of Biochemistry and Molecular BiologyFaculty of Chemistry, Complutense UniversityMadridSpain
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Dias S, Pinto SN, Silva-Herdade AS, Cavaco M, Neves V, Tavares L, Oliveira M, Andreu D, Coutinho A, Castanho MARB, Veiga AS. Quantitative Imaging of the Action of vCPP2319, an Antimicrobial Peptide from a Viral Scaffold, against Staphylococcus aureus Biofilms of a Clinical Isolate. ACS Infect Dis 2023; 9:1889-1900. [PMID: 37669146 PMCID: PMC10580319 DOI: 10.1021/acsinfecdis.3c00195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 09/07/2023]
Abstract
The formation of biofilms is a common virulence factor that makes bacterial infections difficult to treat and a major human health problem. Biofilms are bacterial communities embedded in a self-produced matrix of extracellular polymeric substances (EPS). In this work, we show that vCPP2319, a polycationic peptide derived from the capsid protein of Torque teno douroucouli virus, is active against preformed Staphylococcus aureus biofilms produced by both a reference strain and a clinical strain isolated from a diabetic foot infection, mainly by the killing of biofilm-embedded bacteria. The direct effect of vCPP2319 on bacterial cells was imaged using atomic force and confocal laser scanning microscopy, showing that the peptide induces morphological changes in bacterial cells and membrane disruption. Importantly, vCPP2319 exhibits low toxicity toward human cells and high stability in human serum. Since vCPP2319 has a limited effect on the biofilm EPS matrix itself, we explored a combined effect with α-amylase (EC 3.2.1.1), an EPS matrix-degrading enzyme. In fact, α-amylase decreases the density of S. aureus biofilms by 2.5-fold. Nonetheless, quantitative analysis of bioimaging data shows that vCPP2319 partially restores biofilm compactness after digestion of the polysaccharides, probably due to electrostatic cross-bridging of the matrix nucleic acids, which explains why α-amylase fails to improve the antibacterial action of the peptide.
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Affiliation(s)
- Susana
A. Dias
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Sandra N. Pinto
- iBB-Institute
for Bioengineering and Biosciences and Associate Laboratory i4HB −
Institute for Health and Bioeconomy at Department of Bioengineering, Instituto Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana S. Silva-Herdade
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Marco Cavaco
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Vera Neves
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Luís Tavares
- CIISA
− Centro de Investigação Interdisciplinar em
Sanidade Animal, Faculdade de Medicina Veterinária, Universidade
de Lisboa, Av. da Universidade
Técnica, 1300-477 Lisboa, Portugal
- Laboratório
Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Manuela Oliveira
- CIISA
− Centro de Investigação Interdisciplinar em
Sanidade Animal, Faculdade de Medicina Veterinária, Universidade
de Lisboa, Av. da Universidade
Técnica, 1300-477 Lisboa, Portugal
- Laboratório
Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - David Andreu
- Department
of Medicine and Life Sciences, Pompeu Fabra
University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Ana Coutinho
- iBB-Institute
for Bioengineering and Biosciences and Associate Laboratory i4HB −
Institute for Health and Bioeconomy at Department of Bioengineering, Instituto Superior Técnico, Universidade de
Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Departamento
de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Miguel A. R. B. Castanho
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Ana Salomé Veiga
- Instituto
de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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Laranjo Tinoco C, Coutinho A, Cardoso A, Araújo AS, Matos R, Anacleto S, Mota P. Efficacy and safety of fluoroless ureteroscopy and retrograde intrarenal surgery for the treatment of urolithiasis: A comparative study. Actas Urol Esp 2023; 47:535-542. [PMID: 37207987 DOI: 10.1016/j.acuroe.2023.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/22/2023] [Accepted: 03/26/2023] [Indexed: 05/21/2023]
Abstract
INTRODUCTION Ureteroscopy (URS) and retrograde intrarenal surgery (RIRS) are traditionally guided by fluoroscopy, but the risks of exposure to ionizing radiation may present a matter of concern for patients and urologists. The aim of this study was to evaluate the efficacy and safety of fluoroless URS and RIRS compared with conventional fluoroscopy-guided procedures for the treatment of ureteral and renal stones. MATERIAL AND METHODS Patients treated with URS or RIRS for urolithiasis between August 2018 and December 2019 were retrospectively evaluated and grouped according to the use of fluoroscopy. Data was collected from individual patient records. The main outcomes were stone-free rate (SFR) and complications, compared between the fluoroscopy and fluoroless groups. A subgroup analysis by type of procedure (URS and RIRS) and a multivariate analysis to identify predictors of residual stones were conducted. RESULTS A total of 231 patients met the inclusion criteria: 120 (51.9%) in the conventional fluoroscopy group and 111 (48.1%) in the fluoroless group. No significant differences were found between groups regarding SFR (82.5% vs 90.1%, p=.127) or postoperative complication rate (35.0% vs 31.5%, p=.675). In the subgroup analysis these variables did not present significant differences, regardless of the procedure considered. In the multivariate analysis the fluoroless technique was not an independent predictor of residual lithiasis (OR 0.991; 95% IC 0.407-2.411; p=.983), when adjusted for procedure type, stone size and stone number. CONCLUSION URS and RIRS can be done without fluoroscopic guidance in selected cases, without affecting the efficacy or safety of the procedure.
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Affiliation(s)
| | - A Coutinho
- Urology Department, Hospital de Braga, Braga, Portugal
| | - A Cardoso
- Urology Department, Hospital de Braga, Braga, Portugal
| | - A S Araújo
- Urology Department, Hospital de Braga, Braga, Portugal
| | - R Matos
- Urology Department, Hospital de Braga, Braga, Portugal
| | - S Anacleto
- Urology Department, Hospital de Braga, Braga, Portugal
| | - P Mota
- Urology Department, Hospital de Braga, Braga, Portugal; School of Medicine, University of Minho, Braga, Portugal; Centro Clínico Académico (2CA-Braga), Braga, Portugal
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Silva Cunha P, Antunes DO, Laranjo S, Coutinho A, Abecasis J, Oliveira MM. Case report: Mutation in NPPA gene as a cause of fibrotic atrial myopathy. Front Cardiovasc Med 2023; 10:1149717. [PMID: 37363091 PMCID: PMC10285104 DOI: 10.3389/fcvm.2023.1149717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023] Open
Abstract
Early-onset atrial fibrillation (AF) can be the manifestation of a genetic atrial myopathy. However, specific genetic identification of a mutation causing atrial fibrosis is rare. We report a case of a young patient with an asymptomatic AF, diagnosed during a routine examination. The cardiac MRI revealed extensive atrial fibrosis and the electrophysiology study showed extensive areas of low voltage. The genetic investigation identified a homozygous pathogenic variant in the NPPA gene in the index case and the presence of the variant in heterozygosity in both parents.
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Affiliation(s)
- Pedro Silva Cunha
- Arrhythmology, Pacing and Electrophysiology Unit, Cardiology Service, Santa Marta Hospital, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
- Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Cardiovascular Department, Hospital Lusíadas Lisboa, Lisbon, Portugal
| | - Diana Oliveira Antunes
- Genetics Department, Hospital Dona Estefânia, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
- GenoMed Diagnóstico Medicina Molecular, Instituto de Medicina Molecular, Lisbon, Portugal
| | - Sérgio Laranjo
- Arrhythmology, Pacing and Electrophysiology Unit, Cardiology Service, Santa Marta Hospital, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
- NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Ana Coutinho
- GenoMed Diagnóstico Medicina Molecular, Instituto de Medicina Molecular, Lisbon, Portugal
| | - João Abecasis
- Cardiovascular Department, Hospital Lusíadas Lisboa, Lisbon, Portugal
- NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Mário Martins Oliveira
- Arrhythmology, Pacing and Electrophysiology Unit, Cardiology Service, Santa Marta Hospital, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
- Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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Oliveira B, Barros P, Dores M, Rosa G, Cabrita M, Coutinho A. Erectile dysfunction in young people with type I diabetes: Prevalence, comorbidities and therapeutic response. EUR UROL SUPPL 2022. [DOI: 10.1016/s2666-1683(22)02069-9] [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: 11/05/2022] Open
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8
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Dias SA, Pinto SN, Silva-Herdade AS, Cheneval O, Craik DJ, Coutinho A, Castanho MARB, Henriques ST, Veiga AS. A designed cyclic analogue of gomesin has potent activity against Staphylococcus aureus biofilms. J Antimicrob Chemother 2022; 77:3256-3264. [PMID: 36171717 DOI: 10.1093/jac/dkac309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/18/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Infections caused by bacterial biofilms are very difficult to treat. The use of currently approved antibiotics even at high dosages often fails, making the treatment of these infections very challenging. Novel antimicrobial agents that use distinct mechanisms of action are urgently needed. OBJECTIVES To explore the use of [G1K,K8R]cGm, a designed cyclic analogue of the antimicrobial peptide gomesin, as an alternative approach to treat biofilm infections. METHODS We studied the activity of [G1K,K8R]cGm against biofilms of Staphylococcus aureus, a pathogen associated with several biofilm-related infections. A combination of atomic force and real-time confocal laser scanning microscopies was used to study the mechanism of action of the peptide. RESULTS The peptide demonstrated potent activity against 24 h-preformed biofilms through a concentration-dependent ability to kill biofilm-embedded cells. Mechanistic studies showed that [G1K,K8R]cGm causes morphological changes on bacterial cells and permeabilizes their membranes across the biofilm with a half-time of 65 min. We also tested an analogue of [G1K,K8R]cGm without disulphide bonds, and a linear unfolded analogue, and found both to be inactive. CONCLUSIONS The results suggest that the 3D structure of [G1K,K8R]cGm and its stabilization by disulphide bonds are essential for its antibacterial and antibiofilm activities. Moreover, our findings support the potential application of this stable cyclic antimicrobial peptide to fight bacterial biofilms.
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Affiliation(s)
- Susana A Dias
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz 1649-028 Lisboa, Portugal
| | - Sandra N Pinto
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana S Silva-Herdade
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz 1649-028 Lisboa, Portugal
| | - Olivier Cheneval
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072 Australia
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072 Australia
| | - Ana Coutinho
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.,Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande 1749-016 Lisboa, Portugal
| | - Miguel A R B Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz 1649-028 Lisboa, Portugal
| | - Sónia T Henriques
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072 Australia.,School of Biomedical Sciences, Queensland University of Technology, Translational Research Institute, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Brisbane, QLD, 4102 Australia
| | - Ana Salomé Veiga
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz 1649-028 Lisboa, Portugal
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Claro B, González-Freire E, Granja JR, Garcia-Fandiño R, Gallová J, Uhríková D, Fedorov A, Coutinho A, Bastos M. Partition of antimicrobial D-L-α-cyclic peptides into bacterial model membranes. Biochim Biophys Acta Biomembr 2022; 1864:183729. [PMID: 34506796 DOI: 10.1016/j.bbamem.2021.183729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/30/2021] [Accepted: 08/11/2021] [Indexed: 11/29/2022]
Abstract
Fluorescence spectroscopy is used to characterize the partition of three second-generation D,L-α-cyclic peptides to two lipid model membranes. The peptides have proven antimicrobial activity, particularly against Gram positive bacteria, and the model membranes are formed of either with 1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DMPG) or its mixture with 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), at a molar ratio of (1:1). The peptide's intrinsic fluorescence was used in the Steady State and/or Time Resolved Fluorescence Spectroscopy experiments, showing that the peptides bind to the membranes, and the extent of their partition is thereof quantified. The peptide-induced membrane leakage was followed using an encapsulated fluorescent dye. Overall, the partition is mainly driven by electrostatics, but also involves hydrophobic interactions. The introduction of a hydrocarbon tail in one of the residues of the parent peptide, CPR, adjacent to the tryptophan (Trp) residue, significantly improves the partition of the modified peptides, CPRT10 and CPRT14, to both membrane systems. Further, we show that the length of the tail is the main distinguishing factor for the extension of the partition process. The parent peptide induces very limited leakage, at odds with the peptides with tail, that promote fast leakage, increasing in most cases with peptide concentration, and being almost complete for the highest peptide concentration and negatively charged membranes. Overall, the results help the unravelling of the antimicrobial action of these peptides and are well in line with their proven high antimicrobial activity.
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Affiliation(s)
- Bárbara Claro
- CIQUP, Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Eva González-Freire
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Juan R Granja
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Rebeca Garcia-Fandiño
- CIQUP, Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal; Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Jana Gallová
- Faculty of Pharmacy, Comenius University in Bratislava, 832 32 Bratislava, Slovak Republic
| | - Daniela Uhríková
- Faculty of Pharmacy, Comenius University in Bratislava, 832 32 Bratislava, Slovak Republic
| | - Aleksander Fedorov
- iBB - Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- iBB - Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; Department of Chemistry and Biochemistry, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
| | - Margarida Bastos
- CIQUP, Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
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10
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Díaz-García C, Renart ML, Poveda JA, Giudici AM, González-Ros JM, Prieto M, Coutinho A. Probing the Structural Dynamics of the Activation Gate of KcsA Using Homo-FRET Measurements. Int J Mol Sci 2021; 22:ijms222111954. [PMID: 34769384 PMCID: PMC8584343 DOI: 10.3390/ijms222111954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/18/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
The allosteric coupling between activation and inactivation processes is a common feature observed in K+ channels. Particularly, in the prokaryotic KcsA channel the K+ conduction process is controlled by the inner gate, which is activated by acidic pH, and by the selectivity filter (SF) or outer gate, which can adopt non-conductive or conductive states. In a previous study, a single tryptophan mutant channel (W67 KcsA) enabled us to investigate the SF dynamics using time-resolved homo-Förster Resonance Energy Transfer (homo-FRET) measurements. Here, the conformational changes of both gates were simultaneously monitored after labelling the G116C position with tetramethylrhodamine (TMR) within a W67 KcsA background. At a high degree of protein labeling, fluorescence anisotropy measurements showed that the pH-induced KcsA gating elicited a variation in the homo-FRET efficiency among the conjugated TMR dyes (TMR homo-FRET), while the conformation of the SF was simultaneously tracked (W67 homo-FRET). The dependence of the activation pKa of the inner gate with the ion occupancy of the SF unequivocally confirmed the allosteric communication between the two gates of KcsA. This simple TMR homo-FRET based ratiometric assay can be easily extended to study the conformational dynamics associated with the gating of other ion channels and their modulation.
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Affiliation(s)
- Clara Díaz-García
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Maria Lourdes Renart
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
- Correspondence: (M.L.R.); (A.C.)
| | - José Antonio Poveda
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Ana Marcela Giudici
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - José M. González-Ros
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Manuel Prieto
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: (M.L.R.); (A.C.)
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11
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Scanavachi G, Coutinho A, Fedorov AA, Prieto M, Melo AM, Itri R. Lipid Hydroperoxide Compromises the Membrane Structure Organization and Softens Bending Rigidity. Langmuir 2021; 37:9952-9963. [PMID: 34374545 DOI: 10.1021/acs.langmuir.1c00830] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lipid hydroperoxides are key mediators of diseases and cell death. In this work, the structural and dynamic perturbations induced by the hydroperoxidized POPC lipid (POPC-OOH) in fluid POPC membranes, at both 23 and 37 °C, were addressed using advanced small-angle X-ray scattering (SAXS) and fluorescence methodologies. Notably, SAXS reveals that the hydroperoxide group decreases the lipid bilayer bending rigidity. This alteration disfavors the bilayer stacking and increases the swelling in-between stacked bilayers. We further investigated the changes in the apolar/polar interface of hydroperoxide-containing membranes through time-resolved fluorescence/anisotropy experiments of the probe TMA-DPH and time-dependent fluorescence shifts of Laurdan. A shorter mean fluorescence lifetime for TMA-DPH was obtained in enriched POPC-OOH membranes, revealing a higher degree of hydration near the membrane interface. Moreover, a higher microviscosity near TMA-DPH and lower order are predicted for these oxidized membranes, at variance with the usual trend of variation of these two parameters. Finally, the complex relaxation process of Laurdan in pure POPC-OOH membranes also indicates a higher membrane hydration and viscosity in the close vicinity of the -OOH moiety. Altogether, our combined approach reveals that the hydroperoxide group promotes alterations in the membrane structure organization, namely, at the level of membrane order, viscosity, and bending rigidity.
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Affiliation(s)
- Gustavo Scanavachi
- Institute of Physics, University of São Paulo, São Paulo 05508-090, Brazil
| | - Ana Coutinho
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
- Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa 1749-016, Portugal
- Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Alexander Andreevich Fedorov
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Manuel Prieto
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Ana M Melo
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa 1049-001, Portugal
| | - Rosangela Itri
- Institute of Physics, University of São Paulo, São Paulo 05508-090, Brazil
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Peixoto R, Coutinho A, Weschenfelder R, Prolla G, da Rocha Filho D, Andrade A, Rego J, Dos Santos Fernandes G, Crosara Teixeira M, Hoff P, Costa e Silva M, Dienstmann R, Riechelmann R. P-47 5-fluorouracil bolus use in infusional regimens among oncologists: A survey by Brazilian Group of Gastrointestinal Tumors. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.05.102] [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: 11/17/2022] Open
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13
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Lopes-de-Campos D, Pereira-Leite C, Fontaine P, Coutinho A, Prieto M, Sarmento B, Jakobtorweihen S, Nunes C, Reis S. Interface-Mediated Mechanism of Action-The Root of the Cytoprotective Effect of Immediate-Release Omeprazole. J Med Chem 2021; 64:5171-5184. [PMID: 33847502 DOI: 10.1021/acs.jmedchem.1c00251] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Omeprazole is usually administered under an enteric coating. However, there is a Food and Drug Administration-approved strategy that enables its release in the stomach. When locally absorbed, omeprazole shows a higher efficacy and a cytoprotective effect, whose mechanism was still unknown. Therefore, we aimed to assess the effect of the absorption route on the gastric mucosa. 2D and 3D models of dipalmitoylphosphatidylcholine (DPPC) at different pH values (5.0 and 7.4) were used to mimic different absorption conditions. Several experimental techniques, namely, fluorescence studies, X-ray scattering methodologies, and Langmuir monolayers coupled with microscopy, X-ray diffraction, and infrared spectroscopy techniques, were combined with molecular dynamics simulations. The results showed that electrostatic and hydrophobic interactions between omeprazole and DPPC rearranged the conformational state of DPPC. Omeprazole intercalates among DPPC molecules, promoting domain formation with untilted phospholipids. Hence, the local release of omeprazole enables its action as a phospholipid-like drug, which can reinforce and protect the gastric mucosa.
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Affiliation(s)
- Daniela Lopes-de-Campos
- LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal
| | - Catarina Pereira-Leite
- LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal
| | - Philippe Fontaine
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, BP48, 91192 Gif-sur-Yvette, France
| | - Ana Coutinho
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal.,Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Bruno Sarmento
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.,IINFACTS, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Instituto Universitário de Ciências da Saúde, 4585-116 Gandra, Portugal
| | - Sven Jakobtorweihen
- Institute of Thermal Separation Processes, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Cláudia Nunes
- LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal
| | - Salette Reis
- LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal
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14
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Sousa T, Bernardes N, Coutinho A, Prieto M, Melo AM. Effects of the Flanking polyQ Regions and Membrane Physical Properties on Huntingtin Binding to Lipid Vesicles. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.446] [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: 11/26/2022] Open
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15
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Bernier SC, Millette MA, Roy S, Cantin L, Coutinho A, Salesse C. Structural information and membrane binding of truncated RGS9-1 Anchor Protein and its C-terminal hydrophobic segment. Biochim Biophys Acta Biomembr 2021; 1863:183566. [PMID: 33453187 DOI: 10.1016/j.bbamem.2021.183566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/22/2020] [Accepted: 01/10/2021] [Indexed: 01/19/2023]
Abstract
Visual phototransduction takes place in photoreceptor cells. Light absorption by rhodopsin leads to the activation of transducin as a result of the exchange of its GDP for GTP. The GTP-bound ⍺-subunit of transducin then activates phosphodiesterase (PDE), which in turn hydrolyzes cGMP leading to photoreceptor hyperpolarization. Photoreceptors return to the dark state upon inactivation of these proteins. In particular, PDE is inactivated by the protein complex R9AP/RGS9-1/Gβ5. R9AP (RGS9-1 anchor protein) is responsible for the membrane anchoring of this protein complex to photoreceptor outer segment disk membranes most likely by the combined involvement of its C-terminal hydrophobic domain as well as other types of interactions. This study thus aimed to gather information on the structure and membrane binding of the C-terminal hydrophobic segment of R9AP as well as of truncated R9AP (without its C-terminal domain, R9AP∆TM). Circular dichroism and infrared spectroscopic measurements revealed that the secondary structure of R9AP∆TM mainly includes ⍺-helical structural elements. Moreover, intrinsic fluorescence measurements of native R9AP∆TM and individual mutants lacking one tryptophan demonstrated that W79 is more buried than W173 but that they are both located in a hydrophobic environment. This method also revealed that membrane binding of R9AP∆TM does not involve regions near its tryptophan residues, while infrared spectroscopy validated its binding to lipid vesicles. Additional fluorescence measurements showed that the C-terminal segment of R9AP is membrane embedded. Maximum insertion pressure and synergy data using Langmuir monolayers suggest that interactions with specific phospholipids could be involved in the membrane binding of R9AP∆TM.
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Affiliation(s)
- Sarah C Bernier
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Marc-Antoine Millette
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Sarah Roy
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Line Cantin
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada
| | - Ana Coutinho
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Department of Chemistry and Biochemistry, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Christian Salesse
- CUO-Recherche, Centre de recherche du CHU de Québec and Département d'ophtalmologie, Faculté de Médecine, and Regroupement Stratégique PROTEO, Université Laval, Québec, Québec, Canada.
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16
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Giudici AM, Díaz-García C, Renart ML, Coutinho A, Prieto M, González-Ros JM, Poveda JA. Tetraoctylammonium, a Long Chain Quaternary Ammonium Blocker, Promotes a Noncollapsed, Resting-Like Inactivated State in KcsA. Int J Mol Sci 2021; 22:ijms22020490. [PMID: 33419017 PMCID: PMC7825302 DOI: 10.3390/ijms22020490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/28/2020] [Accepted: 01/01/2021] [Indexed: 02/06/2023] Open
Abstract
Alkylammonium salts have been used extensively to study the structure and function of potassium channels. Here, we use the hydrophobic tetraoctylammonium (TOA+) to shed light on the structure of the inactivated state of KcsA, a tetrameric prokaryotic potassium channel that serves as a model to its homologous eukaryotic counterparts. By the combined use of a thermal denaturation assay and the analysis of homo-Förster resonance energy transfer in a mutant channel containing a single tryptophan (W67) per subunit, we found that TOA+ binds the channel cavity with high affinity, either with the inner gate open or closed. Moreover, TOA+ bound at the cavity allosterically shifts the equilibrium of the channel's selectivity filter conformation from conductive to an inactivated-like form. The inactivated TOA+-KcsA complex exhibits a loss in the affinity towards permeant K+ at pH 7.0, when the channel is in its closed state, but maintains the two sets of K+ binding sites and the W67-W67 intersubunit distances characteristic of the selectivity filter in the channel resting state. Thus, the TOA+-bound state differs clearly from the collapsed channel state described by X-ray crystallography and claimed to represent the inactivated form of KcsA.
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Affiliation(s)
- Ana Marcela Giudici
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Instituto de Biología Molecular y Celular (IBMC), Universidad Miguel Hernández, E-03202 Elche, Spain; (A.M.G.); (M.L.R.)
| | - Clara Díaz-García
- Institute for Bioengineering and Bioscience (IBB), Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (A.C.); (M.P.)
| | - Maria Lourdes Renart
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Instituto de Biología Molecular y Celular (IBMC), Universidad Miguel Hernández, E-03202 Elche, Spain; (A.M.G.); (M.L.R.)
| | - Ana Coutinho
- Institute for Bioengineering and Bioscience (IBB), Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (A.C.); (M.P.)
- Departamento de Química e Bioquímica, Faculty of Sciences, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- Institute for Bioengineering and Bioscience (IBB), Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (A.C.); (M.P.)
| | - José M. González-Ros
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Instituto de Biología Molecular y Celular (IBMC), Universidad Miguel Hernández, E-03202 Elche, Spain; (A.M.G.); (M.L.R.)
- Correspondence: (J.M.G.-R.); (J.A.P.); Tel.: +34-966-658-757 (J.M.G.-R.); +34-966-658-466 (J.A.P.)
| | - José Antonio Poveda
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Instituto de Biología Molecular y Celular (IBMC), Universidad Miguel Hernández, E-03202 Elche, Spain; (A.M.G.); (M.L.R.)
- Correspondence: (J.M.G.-R.); (J.A.P.); Tel.: +34-966-658-757 (J.M.G.-R.); +34-966-658-466 (J.A.P.)
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17
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Coutinho A, Georgescu V, Coutanceau C, Redoules D, Sanchez F, Beltrão FC. 17129 Comparative analysis of clinical benefits provided by two facial daily care regimens with the antioxidants ascorbyl glucoside and tocopheryl glucoside for 8 weeks in Brazilian women. J Am Acad Dermatol 2020. [DOI: 10.1016/j.jaad.2020.06.858] [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: 10/22/2022]
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18
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Coutinho A, Beltrao FC, Borotra N, Touya SB, Duplan H, Laure Gaudry A, Jamin CJ, Genies C, Feital A. 18708 Comparative pharmacokinetic evaluation of delivery of three different vitamin C molecules in target tissues: Ascorbyl glucoside, nanoencapsulated vitamin C, and acid ascorbic. J Am Acad Dermatol 2020. [DOI: 10.1016/j.jaad.2020.06.964] [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: 10/22/2022]
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Pinto SN, Dias SA, Cruz AF, Mil-Homens D, Fernandes F, Valle J, Andreu D, Prieto M, Castanho MARB, Coutinho A, Veiga AS. The mechanism of action of pepR, a viral-derived peptide, against Staphylococcus aureus biofilms. J Antimicrob Chemother 2020; 74:2617-2625. [PMID: 31127270 PMCID: PMC6736180 DOI: 10.1093/jac/dkz223] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [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: 12/28/2018] [Revised: 04/06/2019] [Accepted: 04/23/2019] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES To investigate the mechanism of action at the molecular level of pepR, a multifunctional peptide derived from the Dengue virus capsid protein, against Staphylococcus aureus biofilms. METHODS Biofilm mass, metabolic activity and viability were quantified using conventional microbiology techniques, while fluorescence imaging methods, including a real-time calcein release assay, were employed to investigate the kinetics of pepR activity at different biofilm depths. RESULTS Using flow cytometry-based assays, we showed that pepR is able to prevent staphylococcal biofilm formation due to a fast killing of planktonic bacteria, which in turn resulted from a peptide-induced increase in the permeability of the bacterial membranes. The activity of pepR against pre-formed biofilms was evaluated through the application of a quantitative live/dead confocal laser scanning microscopy (CLSM) assay. The results show that the bactericidal activity of pepR on pre-formed biofilms is dose and depth dependent. A CLSM-based assay of calcein release from biofilm-embedded bacteria was further developed to indirectly assess the diffusion and membrane permeabilization properties of pepR throughout the biofilm. A slower diffusion and delayed activity of the peptide at deeper layers of the biofilm were quantified. CONCLUSIONS Overall, our results show that the activity of pepR on pre-formed biofilms is controlled by its diffusion along the biofilm layers, an effect that can be counteracted by an additional administration of peptide. Our study sheds new light on the antibiofilm mechanism of action of antimicrobial peptides, particularly the importance of their diffusion properties through the biofilm matrix on their activity.
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Affiliation(s)
- Sandra N Pinto
- Centro de Química-Física Molecular e IN, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal.,iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal
| | - Susana A Dias
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal
| | - Ana F Cruz
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal
| | - Dalila Mil-Homens
- iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal
| | - Fabio Fernandes
- Centro de Química-Física Molecular e IN, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal.,iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal
| | - Javier Valle
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Barcelona, Spain
| | - David Andreu
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Barcelona, Spain
| | - Manuel Prieto
- Centro de Química-Física Molecular e IN, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal.,iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal
| | - Miguel A R B Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular e IN, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal.,iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais Lisboa, Portugal.,Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande Lisboa, Portugal
| | - Ana Salomé Veiga
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal
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Dessein H, Duflot N, Romano A, Opio C, Pereira V, Mola C, Kabaterene N, Coutinho A, Dessein A. Correction to: Genetic algorithms identify individuals with high risk of severe liver disease caused by schistosomes. Hum Genet 2020; 139:833. [DOI: 10.1007/s00439-020-02181-z] [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: 11/27/2022]
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Dessein H, Duflot N, Romano A, Opio C, Pereira V, Mola C, Kabaterene N, Coutinho A, Dessein A. Genetic algorithms identify individuals with high risk of severe liver disease caused by schistosomes. Hum Genet 2020; 139:821-831. [PMID: 32277285 DOI: 10.1007/s00439-020-02160-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/28/2020] [Indexed: 02/06/2023]
Abstract
Schistosomes induce severe hepatic disease, which is fatal in 2-10% of cases, mortality being higher in cases of co-infection with HBV or HCV. Hepatic disease occurs as a consequence of the chronic inflammation caused by schistosome eggs trapped in liver sinusoids. In certain individuals, the repair process leads to a massive accumulation of fibrosis in the periportal spaces. We and others have shown that genetic variants play a crucial role in disease progression from mild to severe fibrosis and explain why hepatic fibrosis progresses rapidly in certain subjects only. We will review here published findings concerning the strategies that have been used in the analysis of hepatic fibrosis in schistosome-infected individuals, the genetic variants that have associated with fibrosis, and variants in new pathways crucial for fibrosis progression. Together, these studies show that the development of fibrosis is under the tight genetic control of various common variants with moderate effects. This polygenic control has made it possible to develop models that identify schistosome-infected individual at risk of severe hepatic disease. We discuss the performances and limitations of these models.
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Affiliation(s)
- Hélia Dessein
- BILHI Genetics, 60 Avenue André Roussin, 13016, Marseille, France
- UMR_S906-Génétique Et Immunologie Des Maladies Parasitaires, Aix Marseille Université-INSERM, Marseille, France
| | - Nicolas Duflot
- BILHI Genetics, 60 Avenue André Roussin, 13016, Marseille, France
- UMR_S906-Génétique Et Immunologie Des Maladies Parasitaires, Aix Marseille Université-INSERM, Marseille, France
| | - Audrey Romano
- BILHI Genetics, 60 Avenue André Roussin, 13016, Marseille, France
- UMR_S906-Génétique Et Immunologie Des Maladies Parasitaires, Aix Marseille Université-INSERM, Marseille, France
| | - Christopher Opio
- Department of Medicine, Mulago Hospital, Makerere University College of Health Sciences, Kampala, Uganda
| | - Valeria Pereira
- Instituto Aggeu Magalhães, Fiocruz, Fundaçao Oswaldo Cruz, Av. Professor Moraes Rego, S/N Cidade Universitária, Recife, PE, 50740-465, Brazil
| | - Carla Mola
- Instituto Aggeu Magalhães, Fiocruz, Fundaçao Oswaldo Cruz, Av. Professor Moraes Rego, S/N Cidade Universitária, Recife, PE, 50740-465, Brazil
| | - Narcis Kabaterene
- Vector Control Division Uganda, Ministry of Health, Queen's Ln, Kampala, Uganda
| | - Ana Coutinho
- Fundação Oswaldo Cruz Rio de Janeiro, Av. Brasil, 4365, Rio de Janeiro, RJ, 21040-360, Brazil
| | - Alain Dessein
- BILHI Genetics, 60 Avenue André Roussin, 13016, Marseille, France.
- UMR_S906-Génétique Et Immunologie Des Maladies Parasitaires, Aix Marseille Université-INSERM, Marseille, France.
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Gomes AC, Barbosa PS, Coutinho A, Cruz I, Carmo-Fonseca M, Lopes LR. Whole-genome DNA sequencing: The key to detecting a sarcomeric mutation in a ‘false genotype-negative’ family with hypertrophic cardiomyopathy. Revista Portuguesa de Cardiologia (English Edition) 2020. [DOI: 10.1016/j.repce.2019.03.015] [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: 10/23/2022] Open
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Díaz-García C, Hornos F, Giudici AM, Cámara-Artigas A, Luque-Ortega JR, Arbe A, Rizzuti B, Alfonso C, Forwood JK, Iovanna JL, Gómez J, Prieto M, Coutinho A, Neira JL. Human importin α3 and its N-terminal truncated form, without the importin-β-binding domain, are oligomeric species with a low conformational stability in solution. Biochim Biophys Acta Gen Subj 2020; 1864:129609. [PMID: 32234409 DOI: 10.1016/j.bbagen.2020.129609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/13/2020] [Accepted: 03/26/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Eukaryotic cells have a continuous transit of macromolecules between the cytoplasm and the nucleus. Several carrier proteins are involved in this transport. One of them is importin α, which must form a complex with importin β to accomplish its function, by domain-swapping its 60-residue-long N terminus. There are several human isoforms of importin α; among them, importin α3 has a particularly high flexibility. METHODS We studied the conformational stability of intact importin α3 (Impα3) and its truncated form, where the 64-residue-long, N-terminal importin-β-binding domain (IBB) has been removed (ΔImpα3), in a wide pH range, with several spectroscopic, biophysical, biochemical methods and with molecular dynamics (MD). RESULTS Both species acquired native-like structure between pH 7 and 10.0, where Impα3 was a dimer (with an apparent self-association constant of ~10 μM) and ΔImpα3 had a higher tendency to self-associate than the intact species. The acquisition of secondary, tertiary and quaternary structure, and the burial of hydrophobic patches, occurred concomitantly. Both proteins unfolded irreversibly at physiological pH, by using either temperature or chemical denaturants, through several partially folded intermediates. The MD simulations support the presence of these intermediates. CONCLUSIONS The thermal stability of Impα3 at physiological pH was very low, but was higher than that of ΔImpα3. Both proteins were stable in a narrow pH range, and they unfolded at physiological pH populating several intermediate species. GENERAL SIGNIFICANCE The low conformational stability explains the flexibility of Impα3, which is needed to carry out its recognition of complex cargo sequences.
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Affiliation(s)
- Clara Díaz-García
- iBB- Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Felipe Hornos
- IDIBE, Universidad Miguel Hernández, 03202 Elche, Alicante, Spain
| | | | - Ana Cámara-Artigas
- Departamento de Química y Física, Research Center CIAIMBITAL, Universidad de Almería- ceiA3, 04120 Almería, Spain
| | - Juan Román Luque-Ortega
- Centro de Investigaciones Biológicas Margarita Salas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Arantxa Arbe
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU), Materials Physics Center (MPC), 20018 San Sebastián, Spain
| | - Bruno Rizzuti
- CNR-NANOTEC, Licryl-UOS Cosenza and CEMIF.Cal, Department of Physics, University of Calabria, Via P. Bucci, Cubo 31 C, 87036 Arcavacata di Rende, Cosenza, Italy
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas Margarita Salas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Juan L Iovanna
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13288 Marseille, France
| | - Javier Gómez
- IDIBE, Universidad Miguel Hernández, 03202 Elche, Alicante, Spain
| | - Manuel Prieto
- iBB- Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Ana Coutinho
- iBB- Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1649-004 Lisboa, Portugal
| | - José L Neira
- IDIBE, Universidad Miguel Hernández, 03202 Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos, Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009 Zaragoza, Spain.
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Abstract
IntroductionSleep paralysis (SP) is relatively frequent condition, occurring either at sleep onset or sleep offset. It occurs at least once in a lifetime in 40–50% of normal subjects. During SP, the patient experiences gross motor paralysis, while the sensory system is clear. Hypnogogic and hypnopompic hallucinations are common. This experience might be interpreted as a spiritual phenomenon in several cultures, each one with different interpretations and attributions.ObjectiveThe authors revisit the clinical presentation of sleep paralysis and how this sleep disorder is seen from a cultural perspective.AimsTo describe several cultural interpretations of SP.MethodsA literature review of the theme is shortly surveyed.ResultsIt is very common during an episode of SP sensing the presence of menacing intruders in one's bedroom. Supernatural accounts of this hallucinated intruder are common across cultures. It has been traditionally labeled “ghost oppression” among the Chinese. In the Abruzzo region (Italy), the supernatural interpretation of the phenomena is called the Pandafeche attack. One study found that nearly half (48%) of the participants from the general Egyptian population believed their SP to be caused by the Jinn, a spirit-like creature. In Southwest Nigeria, Ogun Oru is a traditional explanation for nocturnal neuropsychiatric disturbances. The characteristics of the ‘a dead body climbed on top of me’ phenomenon suggest that is identical to sleep paralysis and a frequent experience among Mexican adolescents.ConclusionsDepending on the etiological interpretations of SP, which is largely culturally determined, patients react to the event in specific ways.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Pereira-Leite C, Jamal SK, Almeida JP, Coutinho A, Prieto M, Cuccovia IM, Nunes C, Reis S. Neutral Diclofenac Causes Remarkable Changes in Phosphatidylcholine Bilayers: Relevance for Gastric Toxicity Mechanisms. Mol Pharmacol 2020; 97:295-303. [DOI: 10.1124/mol.119.118299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
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Díaz-García C, Lourdes Renart M, Giudici AM, António Poveda J, Manuel González-Ros J, Nuno Berberan-Santos M, Coutinho A, Prieto M. Conformational Plasticity of the KcsA Channel from Advanced Time-Resolved Homo-FRET Methodologies. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.244] [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: 10/25/2022] Open
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Neira JL, Díaz-García C, Prieto M, Coutinho A. The C-terminal SAM domain of p73 binds to the N terminus of MDM2. Biochim Biophys Acta Gen Subj 2019; 1863:760-770. [DOI: 10.1016/j.bbagen.2019.01.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/25/2019] [Accepted: 01/31/2019] [Indexed: 01/10/2023]
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Da Silva ES, Moura NMM, Coutinho A, Dražić G, Teixeira BMS, Sobolev NA, Silva CG, Neves MGPMS, Prieto M, Faria JL. β-Cyclodextrin as a Precursor to Holey C-Doped g-C 3 N 4 Nanosheets for Photocatalytic Hydrogen Generation. ChemSusChem 2018; 11:2681-2694. [PMID: 29975819 DOI: 10.1002/cssc.201801003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/19/2018] [Indexed: 05/15/2023]
Abstract
A green, template-free and easy-to-implement strategy was developed to access holey g-C3 N4 (GCN) nanosheets doped with carbon. The protocol involves heating dicyandiamide with β-cyclodextrin (βCD) prior to polymerization. The local symmetry of the GCN skeleton is broken, yielding CxGCN (x corresponds to the initial amount of βCD used) with pores and a distorted structure. The electronic, emission, optical and textural properties of the best-performing material, C2GCN, were significantly modified as compared to bulk GCN. The spectroscopic and luminescent features of C2GCN show the characteristic π-π* electronic transition of GCN, accompanied by much stronger n-π* electronic transitions owing to the porous and distorted network. These new electronic transitions, along with the presence of additional carbon synergistically contributed to enhanced visible light absorption and restrained recombination of electron-hole pairs. Steady-state and time-resolved photoluminescence showed an effective quench of the fluorescence emission, accompanied by a decrease of fluorescence lifetime of C2GCN (2.20 ns) in comparison with GCN (5.85 ns), owing to the delocalization of electron and holes to new recombination centers. The photocatalytic activity of C2GCN was attributed to efficient charge carrier separation and improved visible-light absorbing ability. As result, C2GCN exhibited ∼5 times higher photocatalytic H2 generation under visible light than bulk GCN.
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Affiliation(s)
- Eliana S Da Silva
- Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal
| | - Nuno M M Moura
- QOPNA, Department of Chemistry, Universidade de Aveiro, 3810-193, Aveiro, Portugal
| | - Ana Coutinho
- CQFM-IN and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal
| | - Goran Dražić
- Department of Materials Chemistry, National Institute of Chemistry, 1000, Ljubljana, Slovenia
| | - Bruno M S Teixeira
- Physics Department and i3N, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Nikolai A Sobolev
- Physics Department and i3N, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Cláudia G Silva
- Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal
| | - M Graça P M S Neves
- QOPNA, Department of Chemistry, Universidade de Aveiro, 3810-193, Aveiro, Portugal
| | - Manuel Prieto
- CQFM-IN and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
| | - Joaquim L Faria
- Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal
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Videira MAM, Lobo SAL, Silva LSO, Palmer DJ, Warren MJ, Prieto M, Coutinho A, Sousa FL, Fernandes F, Saraiva LM. Staphylococcus aureushaem biosynthesis and acquisition pathways are linked through haem monooxygenase IsdG. Mol Microbiol 2018; 109:385-400. [DOI: 10.1111/mmi.14060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Marco A. M. Videira
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Oeiras Portugal
| | - Susana A. L. Lobo
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Oeiras Portugal
- iBET, Instituto de Biologia Experimental e Tecnológica; Oeiras Portugal
| | - Liliana S. O. Silva
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Oeiras Portugal
| | - David J. Palmer
- School of Biosciences; University of Kent, Giles Lane; Canterbury UK
| | - Martin J. Warren
- School of Biosciences; University of Kent, Giles Lane; Canterbury UK
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico; Universidade de Lisboa; Lisboa Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico; Universidade de Lisboa; Lisboa Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências; Universidade de Lisboa; Lisboa Portugal
| | - Filipa L. Sousa
- Department of Ecogenomics and Systems Biology; University of Vienna; Vienna Austria
| | - Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico; Universidade de Lisboa; Lisboa Portugal
- Research Unit on Applied Molecular Biosciences−Rede de Química e Tecnologia (UCIBIO-REQUIMTE), Departamento de Química, Faculdade de Ciências e Tecnologia; Universidade Nova de Lisboa; Caparica Portugal
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Oeiras Portugal
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Peixoto R, Riechelmann R, Prolla G, Weschenfelder R, Rego J, Dos Santos Fernandes G, Pereira G, de Oliveira M, da Rocha Filho D, Coutinho A. Treatment choices in metastatic colorectal cancer according to sidedness and RAS/BRAF status: A national survey by the Brazilian Group of Gastrointestinal Tumors (GTG). Ann Oncol 2018. [DOI: 10.1093/annonc/mdy151.264] [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: 11/13/2022] Open
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Sarmento MJ, Coutinho A, Fedorov A, Prieto M, Fernandes F. Membrane Order Is a Key Regulator of Divalent Cation-Induced Clustering of PI(3,5)P 2 and PI(4,5)P 2. Langmuir 2017; 33:12463-12477. [PMID: 28961003 DOI: 10.1021/acs.langmuir.7b00666] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although the evidence for the presence of functionally important nanosized phosphorylated phosphoinositide (PIP)-rich domains within cellular membranes has accumulated, very limited information is available regarding the structural determinants for compartmentalization of these phospholipids. Here, we used a combination of fluorescence spectroscopy and microscopy techniques to characterize differences in divalent cation-induced clustering of PI(4,5)P2 and PI(3,5)P2. Through these methodologies we were able to detect differences in divalent cation-induced clustering efficiency and cluster size. Ca2+-induced PI(4,5)P2 clusters are shown to be significantly larger than the ones observed for PI(3,5)P2. Clustering of PI(4,5)P2 is also detected at physiological concentrations of Mg2+, suggesting that in cellular membranes, these molecules are constitutively driven to clustering by the high intracellular concentration of divalent cations. Importantly, it is shown that lipid membrane order is a key factor in the regulation of clustering for both PIP isoforms, with a major impact on cluster sizes. Clustered PI(4,5)P2 and PI(3,5)P2 are observed to present considerably higher affinity for more ordered lipid phases than the monomeric species or than PI(4)P, possibly reflecting a more general tendency of clustered lipids for insertion into ordered domains. These results support a model for the description of the lateral organization of PIPs in cellular membranes, where both divalent cation interaction and membrane order are key modulators defining the lateral organization of these lipids.
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Affiliation(s)
- Maria J Sarmento
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. , 182 23 Prague, Czech Republic
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- Departamento de Química e Bioquímica, FCUL, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Aleksander Fedorov
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , Campus da Caparica, 2829-516 Caparica, Portugal
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Galukande M, Nakaggwa F, Busisa E, Sekavuga Bbaale D, Nagaddya T, Coutinho A. Long term post PrePex male circumcision outcomes in an urban population in Uganda: a cohort study. BMC Res Notes 2017; 10:522. [PMID: 29084559 PMCID: PMC5663120 DOI: 10.1186/s13104-017-2845-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/23/2017] [Indexed: 11/12/2022] Open
Abstract
Objective The objective of this study was to determine the long term adverse events profile at least a year after safe male circumcision. Results A cohort study, investigating patients who had undergone a non surgical circumcision procedure called Prepex. The study variables included scar appearance and sexual experiences. Clients were contacted for a phone interview and data were collected using a questionnaire, for some, a physical examination was done. We obtained ethical committee approval. Data from 304 out of a possible 625 men were analyzed, the rest was lost to follow up. The follow up period was 12–24 months. The mean age was 28 years. Up to 97% were satisfied with the penile scar appearance and the absence of pain. There was no keloids formation, though one developed a hypertrophic scar. Participants reported improved sexual intercourse enjoyment (post circumcision). Up to 17% resumed sexual intercourse before the 6-week long mandatory abstinence period. The average self-reported healing time was 4.7 weeks. There was a high level of scar appearance satisfaction, there was no keloids formation. There was a perceived improvement of sexual enjoyment after circumcision. Trial registration ClinicalTrials. Gov Identifier: NCT02245126 (Date of registration: September 19, 2014)
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Affiliation(s)
- M Galukande
- International Hospital Kampala, P.O. Box 8177, Kampala, Uganda.
| | - F Nakaggwa
- International Health Sciences University, Kampala, Uganda
| | - E Busisa
- International Hospital Kampala, P.O. Box 8177, Kampala, Uganda
| | - D Sekavuga Bbaale
- Infectious Disease Institute, Makerere University Kampala, Kampala, Uganda
| | - T Nagaddya
- International Health Sciences University, Kampala, Uganda
| | - A Coutinho
- Infectious Disease Institute, Makerere University Kampala, Kampala, Uganda
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Gameiro J, Jorge S, Silveira C, Godinho I, Pereira M, Coutinho A, Tavares J, Nogueira E, Fortes MA, Lopes JA, Gomes da Costa A. SP032GENETIC TESTING IN ADULT NEPHROTIC SYNDROME: A PERTINENT ISSUE? Nephrol Dial Transplant 2017. [DOI: 10.1093/ndt/gfx138.sp032] [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: 11/12/2022] Open
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Amaro M, Šachl R, Jurkiewicz P, Coutinho A, Prieto M, Hof M. Time-resolved fluorescence in lipid bilayers: selected applications and advantages over steady state. Biophys J 2016; 107:2751-2760. [PMID: 25517142 DOI: 10.1016/j.bpj.2014.10.058] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/23/2014] [Accepted: 10/29/2014] [Indexed: 01/23/2023] Open
Abstract
Fluorescence methods are versatile tools for obtaining dynamic and topological information about biomembranes because the molecular interactions taking place in lipid membranes frequently occur on the same timescale as fluorescence emission. The fluorescence intensity decay, in particular, is a powerful reporter of the molecular environment of a fluorophore. The fluorescence lifetime can be sensitive to the local polarity, hydration, viscosity, and/or presence of fluorescence quenchers/energy acceptors within several nanometers of the vicinity of a fluorophore. Illustrative examples of how time-resolved fluorescence measurements can provide more valuable and detailed information about a system than the time-integrated (steady-state) approach will be presented in this review: 1), determination of membrane polarity and mobility using time-dependent spectral shifts; 2), identification of submicroscopic domains by fluorescence lifetime imaging microscopy; 3), elucidation of membrane leakage mechanisms from dye self-quenching assays; and 4), evaluation of nanodomain sizes by time-resolved Förster resonance energy transfer measurements.
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Affiliation(s)
- Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Radek Šachl
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Piotr Jurkiewicz
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Ana Coutinho
- Centre for Molecular Chemistry and Physics and Instituto de Nanociência e Nanotecnologia, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal; Departamento Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Manuel Prieto
- Centre for Molecular Chemistry and Physics and Instituto de Nanociência e Nanotecnologia, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic.
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Maia L, Coutinho A, Carvalho I, Baptista B, Carneiro L. Religious and spiritual implication in the assessment and management of bipolar disorder. Eur Psychiatry 2016. [DOI: 10.1016/j.eurpsy.2016.01.285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
IntroductionReligion/spirituality and medicine have been related in one way or another sense the beginning of our know History. Patients’ beliefs, values and practices influence the way disease is perceived and managed. In order to provide adequate care the physician must have proper knowledge of the patients’ spiritual/religious context, otherwise it may fall prey to errors of diagnostic, inappropriate management and subsequent poor compliance.ObjectivesTo present the case of an adult male (a preacher whose beliefs include mediunity) with delusional ideation of mystical content and mood elation, identified during a religious ceremony.AimsQuestioning the frontier between spiritual/religious beliefs and psychopathology.MethodsA case report is presented and a literature review of the theme is shortly surveyed.ResultsThe case reports to a 53 years old man, who during a religious ceremony presented himself with agitation and disinhibition, removing all his cloths and living the church naked. Additionally it was identified the presence of insomnia, heteroaggressiveness, accelerated speech, mood elation and delusional ideation of mystical and megalomaniac content. Several studies demonstrate the importance of acknowledging the religious/spiritual beliefs of patients. This knowledge allows the psychiatry to correctly identify the existing psychopathology and organize an appropriate intervention plan for the patient.ConclusionsSpiritual and religious beliefs’ influence the way disease is perceiver and managed. Physician should collect a brief spiritual story of the patient and learn about the different religious/spiritual beliefs and practices of their community, in order to understand the full dimension of the individual illness.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Perestrelo J, Mota D, Coutinho A, Santos M, Lapa G. Implications of immunity and inflammation in schizophrenia and related psychotic disorders. Eur Psychiatry 2016. [DOI: 10.1016/j.eurpsy.2016.01.2163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
IntroductionIntricate interactions between the immune system and the brain might have important etiological and therapeutic implications for neuropsychiatric brain disorders. A probable association between schizophrenia and the immune system was postulated over a century ago, and is supported by epidemiological and genetic studies pointing to links with infection and inflammation.ObjectiveTo describe some important areas of research regarding immune response in schizophrenia and related psychotic disorders and discuss potential mechanisms and therapeutic implications of these findings.AimsAssociations between immune response, inflammation and schizophrenia and related psychotic disorders are reviewed.MethodsA literature review of the theme is surveyed. Several articles were search on MEDLINE with the keywords: schizophrenia, psychosis, inflammation, immunity, infection.ResultsSchizophrenia is a multifactorial disease. It is associated with multiple genetic loci that confer risk, in addition to developmental and postnatal risk factors. Antipsychotic-naive first-episode psychosis and acute psychotic relapse seems to be associated with increased serum concentrations of interleukin 6 and other proinflammatory cytokines, which are normalized after remission of symptoms with antipsychotic treatment.ConclusionsInflammation and immune dysfunction might contribute to cognitive, negative, and positive symptoms in schizophrenia. Identification of specific inflammatory pathways for neuropsychiatric symptoms would provide novel targets for therapeutic intervention.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Sarmento MJ, Pinto SN, Coutinho A, Prieto M, Fernandes F. Accurate quantification of inter-domain partition coefficients in GUVs exhibiting lipid phase coexistence. RSC Adv 2016. [DOI: 10.1039/c6ra13170k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Giant unilamellar vesicles (GUVs) with phase coexistence allow for the recovery of inter-domain partition coefficients (Kp) of fluorescent molecules through comparison of fluorescence intensities in each phase.
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Affiliation(s)
- M. J. Sarmento
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology
- Instituto Superior Técnico
- University of Lisbon
- Lisbon
- Portugal
| | - S. N. Pinto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology
- Instituto Superior Técnico
- University of Lisbon
- Lisbon
- Portugal
| | - A. Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology
- Instituto Superior Técnico
- University of Lisbon
- Lisbon
- Portugal
| | - M. Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology
- Instituto Superior Técnico
- University of Lisbon
- Lisbon
- Portugal
| | - F. Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology
- Instituto Superior Técnico
- University of Lisbon
- Lisbon
- Portugal
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Porto F, Coutinho A, Pinto A, Gualano B, Duran F, Prando S, Ono C, Spindola L, de Oliveira M, do Vale P, Nitrini R, Buchpiguel C, Brucki S. Effects of aerobic training on cognition and brain glucose metabolism in subjects with MCI. J Neurol Sci 2015. [DOI: 10.1016/j.jns.2015.08.192] [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: 11/28/2022]
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Sousa T, Castro RE, Pinto SN, Coutinho A, Lucas SD, Moreira R, Rodrigues CMP, Prieto M, Fernandes F. Deoxycholic acid modulates cell death signaling through changes in mitochondrial membrane properties. J Lipid Res 2015; 56:2158-71. [PMID: 26351365 DOI: 10.1194/jlr.m062653] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Indexed: 12/21/2022] Open
Abstract
Cytotoxic bile acids, such as deoxycholic acid (DCA), are responsible for hepatocyte cell death during intrahepatic cholestasis. The mechanisms responsible for this effect are unclear, and recent studies conflict, pointing to either a modulation of plasma membrane structure or mitochondrial-mediated toxicity through perturbation of mitochondrial outer membrane (MOM) properties. We conducted a comprehensive comparative study of the impact of cytotoxic and cytoprotective bile acids on the membrane structure of different cellular compartments. We show that DCA increases the plasma membrane fluidity of hepatocytes to a minor extent, and that this effect is not correlated with the incidence of apoptosis. Additionally, plasma membrane fluidity recovers to normal values over time suggesting the presence of cellular compensatory mechanisms for this perturbation. Colocalization experiments in living cells confirmed the presence of bile acids within mitochondrial membranes. Experiments with active isolated mitochondria revealed that physiologically active concentrations of DCA change MOM order in a concentration- and time-dependent manner, and that these changes preceded the mitochondrial permeability transition. Importantly, these effects are not observed on liposomes mimicking MOM lipid composition, suggesting that DCA apoptotic activity depends on features of mitochondrial membranes that are absent in protein-free mimetic liposomes, such as the double-membrane structure, lipid asymmetry, or mitochondrial protein environment. In contrast, the mechanism of action of cytoprotective bile acids is likely not associated with changes in cellular membrane structure.
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Affiliation(s)
- Tânia Sousa
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Rui E Castro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Sandra N Pinto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal Departamento de Química e Bioquímica, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Susana D Lucas
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Rui Moreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Cecília M P Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
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Phillips S, Graham J, Coutinho A, Racicot M, Beauchamp C. Does egg vitrification displace the first polar body - meiotic spindle axis? Fertil Steril 2015. [DOI: 10.1016/j.fertnstert.2015.07.596] [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: 11/25/2022]
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Rodrigues F, Coutinho A, Cardoso C. Correlation of causal factors that influence construction safety performance: A model. Work 2015; 51:721-30. [DOI: 10.3233/wor-152030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Moraes-Fontes M, Costa N, Santos C, Coutinho A, Fesel C. FRI0016 IGE as a Biomarker of Regulatory T Cell Activity in Autoimmune Diseases. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.2543] [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: 11/03/2022]
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Melo AM, Fedorov A, Prieto M, Coutinho A. Exploring homo-FRET to quantify the oligomer stoichiometry of membrane-bound proteins involved in a cooperative partition equilibrium. Phys Chem Chem Phys 2015; 16:18105-17. [PMID: 24722583 DOI: 10.1039/c4cp00060a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The establishment of protein-protein interactions between membrane-bound proteins is associated with several biological functions and dysfunctions. Here, an analytical framework that uses energy homo transfer to directly probe quantitatively the oligomerization state of membrane-bound proteins engaged in a three-state cooperative partition is presented. Briefly, this model assumes that monomeric protein molecules partition into the bilayer surface and reversibly assemble into oligomers with k subunits. A general equation relating the overall steady-state fluorescence anisotropy of the sample to its fractional labeling was derived by considering explicitly that the anisotropy of mixed oligomers containing i-labeled monomers is inversely proportional to the number of labeled subunits per oligomer (Runnels and Scarlata limit). This method was very robust in describing the electrostatic interaction of Alexa Fluor 488 fluorescently labeled lysozyme (Lz-A488) with phosphatidylserine-containing membranes. The pronounced decrease detected in the fluorescence anisotropy of Lz-A488 always correlated with the system reaching a high membrane surface density of the protein (at a low lipid-to-protein (L/P) molar ratio). The occurrence of energy homo transfer-induced fluorescence depolarization was further confirmed by measuring the anisotropy decays of Lz-A488 under these conditions. A global analysis of the steady-state anisotropy data obtained under a wide range of experimental conditions (variable anionic lipid content of the liposomes, L/P molar ratios and protein fractional labeling) confirmed that membrane-bound Lz-A488 assembled into oligomeric complexes, possibly with a stoichiometry of k = 6 ± 1. This study illustrates that even in the presence of a coupled partition-oligomerization equilibrium, steady-state anisotropy measurements provide a simple and reliable tool to monitor the self-assembly of membrane-bound proteins.
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Affiliation(s)
- Ana M Melo
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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Fernandes F, Coutinho A, Prieto M, Loura LMS. Electrostatically driven lipid-protein interaction: Answers from FRET. Biochim Biophys Acta 2015; 1848:1837-48. [PMID: 25769805 DOI: 10.1016/j.bbamem.2015.02.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/23/2015] [Indexed: 12/13/2022]
Abstract
Electrostatics govern the association of a large number of proteins with cellular membranes. In some cases, these proteins present specialized lipid-binding modules or membrane targeting domains while in other cases association is achieved through nonspecific interaction of unstructured clusters of basic residues with negatively charged lipids. Given its spatial resolution in the nanometer range, Förster resonance energy transfer (FRET) is a powerful tool to give insight into protein-lipid interactions and provide molecular level information which is difficult to retrieve with other spectroscopic techniques. In this review we present and discuss the basic formalisms of both hetero- and homo-FRET pertinent to the most commonly encountered problems in lipid-protein interaction studies and highlight some examples of implementations of different FRET methodologies to characterize lipid/protein systems in which electrostatic interactions play a crucial role. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís M S Loura
- Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal.
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Sarmento MJ, Coutinho A, Prieto M, Fernandes F. Analysis of PI(4,5)P2 Lateral Organization at the Plasma Membrane of Living Cells Through FRET. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.1873] [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: 10/24/2022] Open
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46
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Sousa TPMD, Castro RE, Pinto SN, Coutinho A, Lucas SD, Moreira R, Rodrigues CM, Prieto M, Fernandes F. The Cytotoxic Bile Acid DCA Modulates Apoptotic Signalling through Alteration of Mitochondrial Membrane Properties. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.1342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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47
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Melo AM, Fedorov A, Prieto M, Coutinho A. Oligomer Stoichiometry of Membrane-Bound Proteins Involved in a Cooperative Partition Equilibrium: A Homo-FRET Study. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.545] [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: 11/24/2022] Open
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Sousa T, Coutinho A, Banerjee S, Castro R, Youle R, Rodrigues C, Prieto M, Fernandes F. Binding of Pro-Apoptotic Protein Bax to Cytoprotective UDCA and TUDCA. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.3313] [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: 11/30/2022] Open
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Abstract
Fluorescence correlation spectroscopy (FCS) is a powerful method to investigate molecular interactions based on the variation of diffusion properties at the single-molecule level. This technique allows studying quantitatively the interaction of fluorescently labeled proteins/peptides with lipid vesicles. Here, we describe how to acquire and analyze FCS partition data in order to accurately determine the protein/peptide partition coefficients between the aqueous and lipid phases. It is shown that the recovery of unbiased partition coefficients from FCS partition curves (fractional amplitude of the bound species versus lipid concentration) requires considering explicitly the Poissonian loading of the lipid vesicles with the fluorescently labeled protein in order to account for the variable liposome brightness in each sample. Additionally, the impact of a trace amount of a fluorescent non-binding component on the partition curves determined by FCS is also discussed.
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Affiliation(s)
- Ana M Melo
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisbon, Portugal
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Melo AM, Loura LMS, Fernandes F, Villalaín J, Prieto M, Coutinho A. Electrostatically driven lipid-lysozyme mixed fibers display a multilamellar structure without amyloid features. Soft Matter 2014; 10:840-850. [PMID: 24651998 DOI: 10.1039/c3sm52586d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Understanding the interactions between anionic lipid membranes and amyloidogenic proteins/peptides is key to elucidate the molecular mechanisms underlying the membrane-driven amyloid fiber formation. Here, hen egg-white lysozyme was used as a model protein to test whether this same process also occurs with non-amyloidogenic lipid-binding proteins/peptides. A complementary set of biophysical techniques was employed to study the structure and dynamics of the lipid-lysozyme mixed fibers produced at a low lipid/protein molar ratio that have been proposed earlier to present "amyloid-like" characteristics. The multilamellar architecture of these elongated mesoscopic structures was established by performing time-resolved Förster resonance energy transfer measurements, at both bulk (ensemble) and single-fiber level. The predominantly oligomeric lysozyme and phospholipids were both found to display significantly decreased lateral mobility when embedded in these mixed fibers. Notably, two-photon microscopy of Laurdan revealed that a pronounced membrane surface dehydration/increased molecular interfacial packing was produced exclusively in these elongated mixed supramolecular fibers present in the highly polymorphic samples. Infrared spectroscopic studies of lysozyme in these samples further showed that this protein did not exhibit a rich β-sheet structure characteristic of amyloid fibrils. These results support the conclusion that negatively charged lipid membranes do not have the general ability to trigger amyloid fibril formation of non-amyloidogenic proteins.
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Affiliation(s)
- Ana M Melo
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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