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1.
Arch Biochem Biophys ; 746: 109741, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37689256

ABSTRACT

Intercellular communication plays a crucial role in cancer, as well as other diseases, such as inflammation, tissue degeneration, and neurological disorders. One of the proteins responsible for this, are connexins (Cxs), which come together to form a hemichannel. When two hemichannels of opposite cells interact with each other, they form a gap junction (GJ) channel, connecting the intracellular space of these cells. They allow the passage of ions, reactive oxygen and nitrogen species (RONS), and signaling molecules from the interior of one cell to another cell, thus playing an essential role in cell growth, differentiation, and homeostasis. The importance of GJs for disease induction and therapy development is becoming more appreciated, especially in the context of oncology. Studies have shown that one of the mechanisms to control the formation and disruption of GJs is mediated by lipid oxidation pathways, but the underlying mechanisms are not well understood. In this study, we performed atomistic molecular dynamics simulations to evaluate how lipid oxidation influences the channel properties of Cx26 hemichannels, such as channel gating and permeability. Our results demonstrate that the Cx26 hemichannel is more compact in the presence of oxidized lipids, decreasing its pore diameter at the extracellular side and increasing it at the amino terminus domains, respectively. The permeability of the Cx26 hemichannel for water and RONS molecules is higher in the presence of oxidized lipids. The latter may facilitate the intracellular accumulation of RONS, possibly increasing oxidative stress in cells. A better understanding of this process will help to enhance the efficacy of oxidative stress-based cancer treatments.


Subject(s)
Lipid Metabolism , Molecular Dynamics Simulation , Cell Communication , Cell Cycle , Cell Differentiation
2.
Arch Biochem Biophys ; 717: 109136, 2022 03 15.
Article in English | MEDLINE | ID: mdl-35085576

ABSTRACT

It is well established that lipid aldehydes (LAs) are able to increase the permeability of cell membranes and induce their rupture. However, it is not yet clear how LAs are distributed in phase-separated membranes (PSMs), which are responsible for the transport of selected molecules and intracellular signaling. Thus, we investigate here the distribution of LAs in a PSM by coarse-grained molecular dynamics simulations. Our results reveal that LAs derived from mono-unsaturated lipids tend to accumulate at the interface between the liquid-ordered/liquid-disordered domains, whereas those derived from poly-unsaturated lipids remain in the liquid-disordered domain. These results are important for understanding the effects caused by oxidized lipids in membrane structure, properties and organization.


Subject(s)
Aldehydes/chemistry , Cell Membrane , Cell Membrane Permeability , Lipids/chemistry , Molecular Conformation , Molecular Dynamics Simulation , Phase Transition
3.
Plant Dis ; 106(5): 1330-1333, 2022 May.
Article in English | MEDLINE | ID: mdl-34854758

ABSTRACT

Maize striate mosaic virus (MSMV; genus Mastrevirus) was recently reported in maize plants in Brazil and also detected by metagenomic analyses in the corn leafhopper, Dalbulus maidis (DeLong & Wolcott). Although these findings suggested that D. maidis is a potential vector, no transmission studies have been performed. Here, we tested the transmission of MSMV by D. maidis from field-collected infected plants and plants infected with MSMV via leafhopper-mediated transmission in the laboratory; all plants were confirmed positive for MSMV by PCR. In each one of three transmission replicates, aviruliferous D. maidis nymphs and adults were confined together on a source plant during a 4-day acquisition access period (AAP) and subsequently transferred to healthy maize seedlings (10 individuals per test plant) in a series of 4-day inoculation access periods (IAPs). We also tested transmission by the corn aphid, Rhopalosiphum maidis (Fitch) and by mechanical inoculation of healthy maize seedlings. Only D. maidis transmitted MSMV, with overall transmission rates of 29.4 and 39.5% on field-collected infected plants and 18.5% on infected plants in laboratory. D. maidis transmitted MSMV until the third (8 to 12 days after the AAP) or fourth successive IAP (12 to 16 days), with gradual loss in transmission efficiency and rate of viruliferous insects over time, suggesting a persistent but nonpropagative mode of transmission. Infected test plants showed mottling symptoms with mild chlorotic streaks and height reduction. This is the first report of transmission of a mastrevirus by D. maidis, facilitating the completion of Koch's postulate for MSMV.


Subject(s)
Aphids , Geminiviridae , Animals , Brazil , Metagenomics , Zea mays
4.
J Chem Inf Model ; 61(6): 2857-2868, 2021 06 28.
Article in English | MEDLINE | ID: mdl-34080860

ABSTRACT

Lipid oxidation is associated with several inflammatory and neurodegenerative diseases, but many questions to unravel its effects on biomembranes are still open due to the complexity of the topic. For instance, recent studies indicated that phase-separated domains can have a significant effect on membrane function. It is reported that domain interfaces are "hot spots" for pore formation, but the underlying mechanisms and the effect of oxidation-induced phase separation on membranes remain elusive. Thus, to evaluate the permeability of the membrane coexisting of liquid-ordered (Lo) and liquid-disordered (Ld) domains, we performed atomistic molecular dynamics simulations. Specifically, we studied the membrane permeability of nonoxidized or oxidized homogeneous membranes (single-phase) and at the Lo/Ld domain interfaces of heterogeneous membranes, where the Ld domain is composed of either oxidized or nonoxidized lipids. Our simulation results reveal that the addition of only 1.5% of lipid aldehyde molecules at the Lo/Ld domain interfaces of heterogeneous membranes increases the membrane permeability, whereas their addition at homogeneous membranes does not have any effect. This study is of interest for a better understanding of cancer treatment methods based on oxidative stress (causing among others lipid oxidation), such as plasma medicine and photodynamic therapy.


Subject(s)
Lipid Bilayers , Molecular Dynamics Simulation , Cell Membrane , Humans , Lipid Metabolism , Membrane Microdomains , Oxidation-Reduction
5.
Arch Biochem Biophys ; 695: 108548, 2020 11 30.
Article in English | MEDLINE | ID: mdl-32828794

ABSTRACT

Biological membranes are under constant attack of free radicals, which may lead to lipid nitro-oxidation, producing a complex mixture of nitro-oxidized lipids that are responsible for structural and dynamic changes on the membrane. Despite the latter, nitro-oxidized lipids are also associated with several inflammatory and neurodegenerative diseases, the underlying mechanisms of which remain elusive. We perform atomistic molecular dynamics simulations using several isomers of nitro-oxidized lipids to study their effect on the structure and permeability of the membrane, as well as the interaction between the mixture of these products in the phospholipid membrane environment. Our results show that the stereo- and positional isomers have a stronger effect on the properties of the membrane composed of oxidized lipids compared to that containing nitrated lipids. Nevertheless, nitrated lipids lead to three-fold increase in water permeability compared to oxidized lipids. In addition, we show that in a membrane consisting of combined nitro-oxidized lipid products, the presence of oxidized lipids protects the membrane from transient pores. Is well stablished that plasma application and photodynamic therapy produces a number of oxidative species used to kill cancer cells, through membrane damage induced by nitro-oxidative stress. This study is important to elucidate the mechanisms and the molecular level properties involving the reactive species produced during that cancer therapies.


Subject(s)
Lipid Bilayers/chemistry , Molecular Dynamics Simulation , Nitrates/chemistry , Phospholipids/chemistry , Oxidation-Reduction
6.
Bioorg Med Chem Lett ; 30(20): 127469, 2020 10 15.
Article in English | MEDLINE | ID: mdl-32768650

ABSTRACT

The pentacyclic triterpene 3ß,6ß,16ß-tri-hydroxilup-20(29)-ene is a natural product produced by the Brazilian medicinal plant Combretum leprosum. Its cytotoxicity has been previously reported against breast cancer cell lines. The low water solubility of this natural product, that hampers its bioavailability, motivated the investigation of a new nanoparticle formulation containing the triterpene in order to improve its bioactivity. The triterpene was encapsulated in polycaprolactone (PCL) polymer by nanoprecipitation, producing homogenic nanoparticles with nanometer sizes (122.7 ± 2.06 nm), which were characterized by FT-IR, SEM imaging and DSC. The cytotoxicity (MTT method) of the nanoparticle containing the triterpene 1, besides the free natural product and the nanoparticle control (without 1), was assayed against three human tumor cell lines [human colon carcinoma line (HCT116), prostate (PC3) and glioblastoma (SNB19)] and the normal epithelial embryo kidney human cell line (Hek293T). The nanocarrier produced a significative effect in the cytotoxicity of the natural product in the nanoformulation (IC50 0.11-0.26 µg mL-1) when compared with its free form (IC50 1.07-1.44 µg mL-1). Additionally, higher selectivity of the triterpene to the tumor cells was found when it was encapsulated (SI 1.92-4.54) than in its free form (SI 0.42-0.56). In this case, the nanoencapsulated triterpene was more selective to PC3 (SI 3.33) and SNB19 (SI 4.54) tumor cells.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Biological Products/pharmacology , Combretum/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Biological Products/chemistry , Biological Products/isolation & purification , Capsules , Cell Line , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Plant Leaves/chemistry , Structure-Activity Relationship
7.
J Adv Nurs ; 76(12): 3473-3482, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32989824

ABSTRACT

AIMS: To identify clinical symptoms and nursing interventions for stem cell therapy in autoimmune diseases. DESIGN: This is a retrospective, cross-sectional study. METHODS: This study was undertaken with patients diagnosed with type 1 diabetes or multiple sclerosis, undergoing autologous haematopoietic stem cell transplantation from January 2004 - December 2018. Data were registered in a questionnaire, taken during the conditioning regimen comprising cyclophosphamide and rabbit anti-thymocyte globulin. Descriptive statistics and Fisher's exact test were used for data analysis. RESULTS: There were 68 and 23 patients in the multiple sclerosis and type 1 diabetes groups respectively. Skin rash, nausea, vomiting and fever were more frequent and diverse in the type 1 diabetes group. Steroids were used as prophylaxis for anti-thymocyte globulin-associated allergic reactions in 97% of multiple sclerosis patients. Most of the identified symptoms and nursing interventions were more associated with one or other disease group (p < .05) and were more frequent in the type 1 diabetes group. CONCLUSION: Patients with autoimmune diseases who underwent stem cell therapy present differences in their repertoire of adverse events and require disease-specific nursing actions. IMPACT: Our results may enable nurses to establish transplant and disease-specific guidelines to improve prevention and management of adverse events and therefore optimize patient care and therapeutic success.


Subject(s)
Autoimmune Diseases , Hematopoietic Stem Cell Transplantation , Autoimmune Diseases/therapy , Cross-Sectional Studies , Humans , Retrospective Studies , Transplantation, Autologous , Treatment Outcome
8.
J Clin Densitom ; 22(3): 420-428, 2019.
Article in English | MEDLINE | ID: mdl-30100221

ABSTRACT

Anthropomorphic measures among type 1 diabetic patients are changing as the obesity epidemic continues. Excess fat mass may impact bone density and ultimately fracture risk. We studied the interaction between bone and adipose tissue in type 1 diabetes subjects submitted to two different clinical managements: (I) conventional insulin therapy or (II) autologous nonmyeloablative hematopoietic stem-cell transplantation (AHST). The study comprised 3 groups matched by age, gender, height and weight: control (C = 24), type 1 diabetes (T1D = 23) and type 1 diabetes treated with AHST (T1D-AHST = 9). Bone mineral density (BMD) and trabecular bone score (TBS) were assessed by dual X-ray absorptiometry (DXA). 1H Magnetic resonance spectroscopy was used to assess bone marrow adipose tissue (BMAT) in the L3 vertebra, and abdominal magnetic resonance imaging was used to assess intrahepatic lipids (IHL), visceral (VAT) and subcutaneous adipose tissue (SAT). Individuals conventionally treated for T1D were more likely to be overweight (C = 23.8 ± 3.7; T1D = 25.3 ± 3.4; T1D-AHST = 22.5 ± 2.2 Kg/m2; p > 0.05), but there was no excessive lipid accumulation in VAT or liver. Areal BMD of the three groups were similar at all sites; lumbar spine TBS (L3) was lower in type 1 diabetes (p < 0.05). Neither SAT nor VAT had any association with bone parameters. Bone marrow adipose tissue (BMAT) lipid profiles were similar among groups. BMAT saturated lipids were associated with cholesterol, whereas unsaturated lipids had an association with IGF1. Overweight and normal weight subjects with type 1 diabetes have normal areal bone density, but lower trabecular bone scores. Adipose distribution is normal and BMAT volume is similar to controls, irrespective of clinical treatment.


Subject(s)
Adipose Tissue/diagnostic imaging , Bone Marrow/diagnostic imaging , Diabetes Mellitus, Type 1/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Absorptiometry, Photon , Adult , Body Composition , Bone Density , Bone Remodeling , Bone and Bones , Brazil , Cancellous Bone/diagnostic imaging , Case-Control Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 1/therapy , Female , Hematopoietic Stem Cell Transplantation , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Intra-Abdominal Fat/diagnostic imaging , Lipid Metabolism , Liver/diagnostic imaging , Liver/metabolism , Male , Middle Aged , Proton Magnetic Resonance Spectroscopy , Subcutaneous Fat/diagnostic imaging , Transplantation, Autologous , Young Adult
9.
J Nat Prod ; 81(4): 825-837, 2018 04 27.
Article in English | MEDLINE | ID: mdl-29537263

ABSTRACT

Withanolides constitute a valuable class of bioactive natural products because some members of the class are known to exhibit cytotoxic activity and also induce a cytoprotective heat-shock response. In order to understand the relationship between their structures and these dual bioactivities of the withanolide scaffold, we obtained 25 analogues of withaferin A (WA) and withanolide D (WD) including 17 new compounds by semisynthesis involving chemical and microbial transformations. Hitherto unknown 16ß-hydroxy analogues of WA and WD were prepared by their reaction with triphenylphosphine/iodine, providing unexpected 5ß-hydroxy-6α-iodo analogues (iodohydrins) followed by microbial biotransformation with Cunninghamella echinulata and base-catalyzed cyclization of the resulting 16ß-hydroxy iodohydrins. Evaluation of these 25 withanolide analogues for their cytotoxicity and heat-shock-inducing activity (HSA) confirmed the known structure-activity relationships for WA-type withanolides and revealed that WD analogues were less active in both assays compared to their corresponding WA analogues. The 5ß,6ß-epoxide moiety of withanolides contributed to their cytotoxicity but not HSA. Introduction of a 16ß-OAc group to 4,27-di- O-acetyl-WA enhanced cytotoxicity and decreased HSA, whereas introduction of the same group to 4- O-acetyl-WD decreased both activities.


Subject(s)
Biological Products/pharmacology , Cytotoxins/pharmacology , Heat-Shock Response/drug effects , Withanolides/pharmacology , Cell Line , Cell Line, Tumor , HEK293 Cells , Humans , Iodine/metabolism , Organophosphorus Compounds/metabolism , Sarcoma, Ewing/drug therapy , Structure-Activity Relationship
10.
J Environ Manage ; 166: 294-308, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26517278

ABSTRACT

Hydraulic, sanitary, and sulfide control conditions of inverted siphons, particularly in large wastewater systems, can be substantially improved by continuous air injection in the base of the inclined rising branch. This paper presents a simplified approach that was developed for the two-phase flow of the rising branch using the energy equation for a steady pipe flow, based on the average fluid fraction, observed slippage between phases, and isothermal assumption. As in a conventional siphon design, open channel steady uniform flow is assumed in inlet and outlet chambers, corresponding to the wastewater hydraulic characteristics in the upstream and downstream sewers, and the descending branch operates in steady uniform single-phase pipe flow. The proposed approach is tested and compared with data obtained in an experimental siphon setup with two plastic barrels of different diameters operating separately as in a single-barrel siphon. Although the formulations developed are very simple, the results show a good adjustment for the set of the parameters used and conditions tested and are promising mainly for sanitary siphons with relatively moderate heights of the ascending branch.


Subject(s)
Waste Management/methods , Hydrodynamics , Models, Theoretical , Sewage , Sulfides , Waste Management/instrumentation , Wastewater/chemistry
12.
Clin Sci (Lond) ; 128(2): 111-20, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25116724

ABSTRACT

Autologous haematopoietic stem-cell transplantation (AHSCT) has been experimented as a treatment in patients affected by severe forms of multiple sclerosis (MS) who failed to respond to standard immunotherapy. The rationale of AHSCT is to 'reboot' the immune system and reconstitute a new adaptive immunity. The aim of our study was to identify, through a robust and unbiased transcriptomic analysis, any changes of gene expression in T-cells potentially underlying the treatment effect in patients who underwent non-myeloablative AHSCT for treatment of MS. We evaluated by microarray DNA-chip technology the gene expression of peripheral CD4+ and CD8+ T-cell subsets sorted from patients with MS patients before AHSCT, at 6 months, 1 year and 2 years after AHSCT and from healthy control subjects. Hierarchical clustering analysis revealed that reconstituted CD8+ T-cells of MS patients at 2 years post-transplantation, aggregated together with healthy controls, suggesting a normalization of gene expression in CD8+ cells post-therapy. When we compared the gene expression in MS patients before and after therapy, we detected a large number of differentially expressed genes (DEG) in both CD8+ and CD4+ T-cell subsets at all time points after transplantation. We catalogued the biological function of DEG and we selected 27 genes known to be involved in immune function for accurate quantification of gene expression by real-time PCR. The analysis confirmed and extended with quantitative data, a number of significant changes in both the CD4+ and CD8+ T-cells subsets from MS post-transplant. Notably, CD8+ T-cells revealed more extensive changes in the expression of genes involved in effector immune responses.


Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Sclerosis/therapy , Adaptive Immunity/genetics , Adult , CD4-Positive T-Lymphocytes , Female , Gene Expression Profiling , Gene Expression Regulation , Humans , Male , Middle Aged , Multiple Sclerosis/genetics , Multiple Sclerosis/immunology
13.
J Nat Prod ; 78(11): 2738-47, 2015 Nov 25.
Article in English | MEDLINE | ID: mdl-26539727

ABSTRACT

Anteaglonialides A-F (1-6), bearing a spiro[6-(tetrahydro-7-furanyl)cyclohexane-1,2'-naphtho[1,8-de][1,3]-dioxin]-10-one skeleton, three new spirobisnaphthalenes, palmarumycins CE1-CE3 (7-9), nine known palmarumycin analogues, palmarumycins CP5 (10), CP4a (11), CP3 (12), CP17 (13), CP2 (14), and CP1 (15), CJ-12,371 (16), 4-O-methyl CJ-12,371 (17), and CP4 (18), together with a possible artifact, 4a(5)-anhydropalmarumycin CE2 (8a), and four known metabolites, O-methylherbarin (19), herbarin (20), herbaridine B (21), and hyalopyrone (22), were encountered in a cytotoxic extract of a potato dextrose agar culture of Anteaglonium sp. FL0768, an endophytic fungus of the sand spikemoss, Selaginella arenicola. The planar structures and relative configurations of the new metabolites 1-9 were elucidated by analysis of extensive spectroscopic data, and the absolute configuration of 1 was determined by the modified Mosher's ester method. Application of the modified Mosher's ester method combined with the NOESY data resulted in revision of the absolute configuration previously proposed for 10. Co-occurrence of 1-6 and 7-18 in this fungus led to the proposal that the anteagloniolides may be biogenetically derived from palmarumycins. Among the metabolites encountered, anteaglonialide F (6) and known palmarumycins CP3 (12) and CP1 (15) exhibited strong cytotoxic activity against the human Ewing's sarcoma cell line CHP-100, with IC50 values of 1.4, 0.5, and 1.6 µM, respectively.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Naphthalenes/isolation & purification , Selaginellaceae/chemistry , Spiro Compounds/isolation & purification , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Ascomycota/chemistry , Drug Screening Assays, Antitumor , Endophytes/chemistry , Florida , Humans , Inhibitory Concentration 50 , Microbial Sensitivity Tests , Molecular Structure , Naphthalenes/chemistry , Naphthalenes/pharmacology , Naphthoquinones , Nuclear Magnetic Resonance, Biomolecular , Spiro Compounds/chemistry , Spiro Compounds/pharmacology
14.
Chem Biodivers ; 12(3): 432-42, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25766916

ABSTRACT

The cytotoxic activities of extracts (50 µg/ml) from 48 fungal strains, recovered from sediments of Pecém's offshore port terminal (Northeast coast of Brazil), against HCT-116 colon cancer cell lines were investigated. The most promising extract was obtained from strain BRF082, identified as Dichotomomyces cejpii by phylogenetic analyses of partial RPB2 gene sequence. Thus, it was selected for bioassay-guided isolation of the cytotoxic compounds. Large-scale fermentation of BRF082 in potato dextrose broth, followed by chromatographic purification of the bioactive fractions from the liquid medium, yielded gliotoxin (4) and its derivatives acetylgliotoxin G (3), bis(dethio)bis(methylsulfanyl)gliotoxin (1), acetylgliotoxin (5), 6-acetylbis(dethio)bis(methylsulfanyl)gliotoxin (2), besides the quinazolinone alkaloid fiscalin B. All isolated compounds were tested for their cytotoxicities against the tumor cell lines HCT-116, revealing 4 and 3 as the most cytotoxic ones (IC50 0.41 and 1.06 µg/ml, resp.).


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biological Products/chemistry , Biological Products/pharmacology , Fungi/chemistry , Geologic Sediments/microbiology , Antineoplastic Agents/isolation & purification , Biological Products/isolation & purification , Brazil , Colonic Neoplasms/drug therapy , Fungi/genetics , Gliotoxin/analogs & derivatives , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , HCT116 Cells , Humans , Indoles/chemistry , Indoles/isolation & purification , Indoles/pharmacology , Phylogeny , Quinazolines/chemistry , Quinazolines/isolation & purification , Quinazolines/pharmacology
15.
Carbohydr Polym ; 330: 121740, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38368119

ABSTRACT

Cellulose cryogels are promising eco-friendly materials that exhibit low density, high porosity, and renewability. However, the applications of these materials are limited by their lower mechanical and water resistance compared to petrochemical-based lightweight materials. In this work, nanocelluloses were functionalized with cationic and anionic groups, and these nanomaterials were combined to obtain strong and water-resilient cryogels. To prepare the cryogels, anionic and cationic micro- and nanofibrils (CNFs) were produced at three different sizes and combined in various weight ratios, forming electrostatic complexes. The complex phase was concentrated by centrifugation and freeze-dried. Porous and open cellular structures were assembled in all compositions tested (porosity >90 %). Compressive testing revealed that the most resistant cryogels (1.7 MPa) were obtained with equivalent amounts of negatively and positively charged CNFs with lengths between 100 and 1200 nm. The strength at this condition was achieved as CNF electrostatic complexes assembled in thick cells, as observed by synchrotron X-ray tomography. In addition to mechanical strength, electrostatic complexation provided remarkable structural stability in water for the CNF cryogels, without compromising their biodegradability. This route by electrostatic complexation is a practical strategy to combine and concentrate nanocelluloses to tailor biodegradable lightweight materials with high strength and wet stability.

16.
Biomolecules ; 13(7)2023 06 27.
Article in English | MEDLINE | ID: mdl-37509079

ABSTRACT

The potential of cold atmospheric plasma (CAP) in biomedical applications has received significant interest, due to its ability to generate reactive oxygen and nitrogen species (RONS). Upon exposure to living cells, CAP triggers alterations in various cellular components, such as the cell membrane. However, the permeation of RONS across nitrated and oxidized membranes remains understudied. To address this gap, we conducted molecular dynamics simulations, to investigate the permeation capabilities of RONS across modified cell membranes. This computational study investigated the translocation processes of less hydrophilic and hydrophilic RONS across the phospholipid bilayer (PLB), with various degrees of oxidation and nitration, and elucidated the impact of RONS on PLB permeability. The simulation results showed that less hydrophilic species, i.e., NO, NO2, N2O4, and O3, have a higher penetration ability through nitro-oxidized PLB compared to hydrophilic RONS, i.e., HNO3, s-cis-HONO, s-trans-HONO, H2O2, HO2, and OH. In particular, nitro-oxidation of PLB, induced by, e.g., cold atmospheric plasma, has minimal impact on the penetration of free energy barriers of less hydrophilic species, while it lowers these barriers for hydrophilic RONS, thereby enhancing their translocation across nitro-oxidized PLB. This research contributes to a better understanding of the translocation abilities of RONS in the field of plasma biomedical applications and highlights the need for further analysis of their role in intracellular signaling pathways.


Subject(s)
Hydrogen Peroxide , Oxygen , Hydrogen Peroxide/metabolism , Reactive Oxygen Species/metabolism , Cell Membrane/metabolism , Oxygen/metabolism , Molecular Dynamics Simulation , Reactive Nitrogen Species/metabolism , Phospholipids/metabolism
17.
Pediatr Pulmonol ; 58(3): 727-737, 2023 03.
Article in English | MEDLINE | ID: mdl-36382503

ABSTRACT

OBJECTIVE: There have been conflicting reports on the relationship between asthma and COVID-19 severity. This study aimed to compare the risk of death among children with asthma and healthy peers hospitalized due to COVID-19. METHODS: We carried out an analysis of all pediatric patients 2-19 years of age with asthma and COVID-19 registered in Influenza Epidemiological Surveillance Information System-Gripe, a Brazilian nationwide surveillance database, between February 2020 and March 2022. The primary outcome was time to death, which was evaluated considering discharge as a competitive risk using the cumulative incidence function. RESULTS: Among 30,405 hospitalized children with COVID-19, 21,340 (70.2%) had no comorbidities, 6444 (21.2%) had comorbidities other than asthma, 2165 (7.1%) had asthma, and 465 (1.5%) had asthma with other comorbidities. The estimated probability of a fatal outcome for each group was 4.1%, 14.9%, 2.1%, and 10.7%, respectively. After adjustment, children with asthma had a 60% reduction in the hazard of death than healthy peers (hazard ratio [HR] = 0.39, 95% confidence interval [CI], 0.29-0.53, p < 0.0001). Among children with asthma and no other comorbidities, two covariates were independently associated with in-hospital mortality, age ≥12 years, HR = 4.0, 95% CI, 2.5-6.4), and low oxygen saturation at admission (HR = 2.3, 95% CI, 1.4-3.2). CONCLUSION: Children with asthma and no comorbidities had a lower risk of death compared with healthy peers after controlling for clinical and demographic confounding factors.


Subject(s)
Asthma , COVID-19 , Humans , Child , Adolescent , COVID-19/epidemiology , Brazil/epidemiology , SARS-CoV-2 , Asthma/epidemiology , Comorbidity , Hospitalization
18.
Redox Biol ; 57: 102503, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36228438

ABSTRACT

Gap junctions (GJs), essential structures for cell-cell communication, are made of two hemichannels (commonly called connexons), one on each adjacent cell. Found in almost all cells, GJs play a pivotal role in many physiological and cellular processes, and have even been linked to the progression of diseases, such as cancer. Modulation of GJs is under investigation as a therapeutic strategy to kill tumor cells. Furthermore, GJs have also been studied for their key role in activating anti-cancer immunity and propagating radiation- and oxidative stress-induced cell death to neighboring cells, a process known as the bystander effect. While, gap junction (GJ)-based therapeutic strategies are being developed, one major challenge has been the paradoxical role of GJs in both tumor progression and suppression, based on GJ composition, cancer factors, and tumoral context. Therefore, understanding the mechanisms of action, regulation, and the dual characteristics of GJs in cancer is critical for developing effective therapeutics. In this review, we provide an overview of the current understanding of GJs structure, function, and paradoxical pro- and anti-tumoral role in cancer. We also discuss the treatment strategies to target these GJs properties for anti-cancer responses, via modulation of GJ function.

19.
Pharmaceuticals (Basel) ; 16(1)2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36678552

ABSTRACT

Alzheimer's Disease (AD) is characterized by a progressive cholinergic neurotransmission imbalance, with a decrease of acetylcholinesterase (AChE) activity followed by a significant increase of butyrylcholinesterase (BChE) in the later AD stages. BChE activity is also crucial for the development of Aß plaques, the main hallmarks of this pathology. Moreover, systemic copper dyshomeostasis alters neurotransmission leading to AD. In the search for structures targeting both events, a set of novel 6-benzamide purine nucleosides was synthesized, differing in glycone configuration and N7/N9 linkage to the purine. Their AChE/BChE inhibitory activity and metal ion chelating properties were evaluated. Selectivity for human BChE inhibition required N9-linked 6-deoxy-α-d-mannosylpurine structure, while all three tested ß-d-derivatives appeared as non-selective inhibitors. The N9-linked l-nucleosides were cholinesterase inhibitors except the one embodying either the acetylated sugar or the N-benzyl-protected nucleobase. These findings highlight that sugar-enriched molecular entities can tune bioactivity and selectivity against cholinesterases. In addition, selective copper chelating properties over zinc, aluminum, and iron were found for the benzyl and acetyl-protected 6-deoxy-α-l-mannosyl N9-linked purine nucleosides. Computational studies highlight molecular conformations and the chelating molecular site. The first dual target compounds were disclosed with the perspective of generating drug candidates by improving water solubility.

20.
Anal Bioanal Chem ; 400(4): 1153-9, 2011 May.
Article in English | MEDLINE | ID: mdl-21437775

ABSTRACT

Recent advances in the control of molecular engineering architectures have allowed unprecedented ability of molecular recognition in biosensing, with a promising impact for clinical diagnosis and environment control. The availability of large amounts of data from electrical, optical, or electrochemical measurements requires, however, sophisticated data treatment in order to optimize sensing performance. In this study, we show how an information visualization system based on projections, referred to as Projection Explorer (PEx), can be used to achieve high performance for biosensors made with nanostructured films containing immobilized antigens. As a proof of concept, various visualizations were obtained with impedance spectroscopy data from an array of sensors whose electrical response could be specific toward a given antibody (analyte) owing to molecular recognition processes. In addition to discussing the distinct methods for projection and normalization of the data, we demonstrate that an excellent distinction can be made between real samples tested positive for Chagas disease and Leishmaniasis, which could not be achieved with conventional statistical methods. Such high performance probably arose from the possibility of treating the data in the whole frequency range. Through a systematic analysis, it was inferred that Sammon's mapping with standardization to normalize the data gives the best results, where distinction could be made of blood serum samples containing 10(-7) mg/mL of the antibody. The method inherent in PEx and the procedures for analyzing the impedance data are entirely generic and can be extended to optimize any type of sensor or biosensor.


Subject(s)
Biosensing Techniques/methods , Leishmaniasis/diagnosis , Antibodies, Protozoan/blood , Antigens, Protozoan , Chagas Disease/diagnosis , Electric Impedance , Nanostructures
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