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1.
Mol Cell Proteomics ; 20: 100069, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33716169

RESUMO

The dynamic modification of specific serine and threonine residues of intracellular proteins by O-linked N-acetyl-ß-D-glucosamine (O-GlcNAc) mitigates injury and promotes cytoprotection in a variety of stress models. The O-GlcNAc transferase (OGT) and the O-GlcNAcase are the sole enzymes that add and remove O-GlcNAc, respectively, from thousands of substrates. It remains unclear how just two enzymes can be specifically controlled to affect glycosylation of target proteins and signaling pathways both basally and in response to stress. Several lines of evidence suggest that protein interactors regulate these responses by affecting OGT and O-GlcNAcase activity, localization, and substrate specificity. To provide insight into the mechanisms by which OGT function is controlled, we have used quantitative proteomics to define OGT's basal and stress-induced interactomes. OGT and its interaction partners were immunoprecipitated from OGT WT, null, and hydrogen peroxide-treated cell lysates that had been isotopically labeled with light, medium, and heavy lysine and arginine (stable isotopic labeling of amino acids in cell culture). In total, more than 130 proteins were found to interact with OGT, many of which change their association upon hydrogen peroxide stress. These proteins include the major OGT cleavage and glycosylation substrate, host cell factor 1, which demonstrated a time-dependent dissociation after stress. To validate less well-characterized interactors, such as glyceraldehyde 3-phosphate dehydrogenase and histone deacetylase 1, we turned to parallel reaction monitoring, which recapitulated our discovery-based stable isotopic labeling of amino acids in cell culture approach. Although the majority of proteins identified are novel OGT interactors, 64% of them are previously characterized glycosylation targets that contain varied domain architecture and function. Together these data demonstrate that OGT interacts with unique and specific interactors in a stress-responsive manner.


Assuntos
N-Acetilglucosaminiltransferases/metabolismo , Estresse Oxidativo , Animais , Células Cultivadas , Fibroblastos/metabolismo , Camundongos , N-Acetilglucosaminiltransferases/genética , Mapas de Interação de Proteínas , Proteômica
2.
Horm Metab Res ; 52(7): 492-499, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32542627

RESUMO

Variants of vitamin D metabolism-genes may predispose to type 2 diabetes (T2D). This study investigated the impact of these variants on disease susceptibility, Vitamin D, parathyroid hormone, C-peptide and HbA1c levels before and after cholecalciferol supplementation in patients with T2D.Twelve polymorphisms within CYP2R1, CYP27B1, DBP, VDR and CYP24A1 were genotyped in 553 T2D patients and 916 controls. In addition 65 patients receiving either cholecalciferol or placebo were analyzed during 6 months intervention and 6 months follow-up.T2D risk alleles are VDR rs7975232 "G" (pc=0.031), rs1544410 "G" (pc=0.027) and CYP2R1 rs10741657 "A" (pc=0.016). Patients with genotypes CYP27B1 rs10877012 "CC" (pc=4x10-5), DBP rs7041 "GG" (pc=0.003), rs4588 "CC" (pc = 3x10-4), CYP24A1 rs2585426 "CG" (pc=0.006) and rs2248137 "CG" (pc=0.001) showed lower 25(OH)D3 and DBP rs4588 "CC" lower 1,25(OH)2D3 levels (pc=0.005). Whereas DBP rs4588 "CC" (pc=0.009), CYP27B1 rs10877012 "AC" (pc=0.059), VDR rs7975323 "AG" (pc=0.033) and rs1544410 "GG" (pc=0.013) are associated with higher 25(OH)D3 levels at 6 months' follow-up. Significant PTH suppression was detected for CYP2R1 "AG" (pc=0.002), DBP rs4588 "CC" (pc<0.001), VDR rs110735810 "CT" (pc<0.001) and CYP24A1 rs2248137 "GG" (pc=0.021).Genetic variants of the vitamin D system predispose to type 2 diabetes and regulate - partially - vitamin D metabolism, concentrations and the vitamin D status. Vitamin D insufficiency is a T2D risk factor. The response to cholecalciferol supplementation can be measured as 25(OH)D3 increment and PTH suppression. This process is regulated by genes of the vitamin D system conferring modest T2D risk.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Deficiência de Vitamina D/genética , Vitamina D/uso terapêutico , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Colestanotriol 26-Mono-Oxigenase/genética , Estudos de Coortes , Família 2 do Citocromo P450/genética , Diabetes Mellitus Tipo 2/metabolismo , Suplementos Nutricionais , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Redes e Vias Metabólicas/genética , Pessoa de Meia-Idade , Testes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Dados Preliminares , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de Calcitriol/genética , Resultado do Tratamento , Vitamina D/metabolismo , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/metabolismo , Proteína de Ligação a Vitamina D/genética , Vitamina D3 24-Hidroxilase/genética
3.
J Am Chem Soc ; 141(30): 12121-12127, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31276394

RESUMO

We developed a method to colloidally synthesize atomically thin metal sulfides (ATMS). Unlike conventional 2D systems such as MoS2 and graphene, none of the systems developed here are inherently layered compounds nor have known layered polymorphs in their bulk forms. The synthesis proceeds via a cation-exchange reaction starting from single- and multi-layer Ag2S and going to various metal sulfides. The synthesized ATMS retain their size and shape during the cation-exchange reaction and are either single-layer or a few-layer, depending on the starting Ag2S samples. They have lateral dimensions on the order of 5-10 nm and are colloidally stabilized by Z- and L-type ligands. Here, we demonstrate the synthesis of single-layer and a few-layer ZnS, CdS, CoS2, and PbS. We find that the optical properties of these ATMS are quite distinct from the platelet or quantum-dot versions of the same metal sulfides.

4.
J Chem Phys ; 151(11): 114111, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31542005

RESUMO

Photoelectrochemical (PEC) water splitting is one of the most important approaches being investigated for solar fuel generation. In this study, we determine the maximum thermodynamic power conversion efficiencies (PCEs) of PEC water splitting two-bandgap tandem devices that produce multiple carriers per photon absorbed via Multiple Exciton Generation (MEG) or Singlet Fission (SF) and in the presence of solar concentration. Here, we employ a detailed balance thermodynamic analysis to determine the effects of top cell thickness, solar concentration, carrier multiplication, electrode overvoltage (VO), and water absorption on PEC power conversion efficiency for water splitting cells. We have found a maximum PEC power conversion efficiency of 62.9% in cells using two ideal tandem MEG absorbers with bandgaps of 0.3 and 1.2 eV at 1000-suns solar concentration and 0 overvoltage; the maximum PCE for two tandem SF absorbers under the same conditions is nearly the same at 59% with the same values for the absorption thresholds. A very interesting and important result was that, upon thinning the top cell, the range of viable bandgaps for both the top and bottom cells is extended by as much as 0.5-1 eV while still maintaining high maximum conversion efficiency (60-63%). The effects of imposing different solar concentrations from 1X to 1000X and having different tandem configurations of SF and MEG layers were also studied.

5.
Chem Biodivers ; 16(4): e1800525, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30614195

RESUMO

A natural and biocompatible extract of garlic as a support, decorated with silver nanoparticles, is a proposal to generate an effective antifungal agent against dermatophytes at low concentrations. Silver nanoparticles (AgNPs) with a diameter of 26±7 nm were synthesized and their antimycotic activity was examined against Trichophyton rubrum (T. rubrum), inhibiting 94 % of growth at a concentration of 0.08 mg ml-1 . Allium sativum (garlic) extract was also obtained (AsExt), and its MIC was 0.04 mg ml-1 . To increase the antifungal capacity of those systems, AsExt was decorated with AgNPs, obtaining AsExt-AgNPs. Using an AsExt concentration of 0.04 mg ml-1 in independent experiments with concentrations from 0.01 to 0.08 mg ml-1 of AgNPs, it was possible to inhibit T. rubrum at all AgNPs concentrations; it proves a synergistic effect between AgNPs and AsExt. Even if 1 % of the minimum inhibitory concentration of AsExt (0.0004 mg ml-1 ) is used, it was possible to inhibit T. rubrum at all concentrations of AgNPs, demonstrating the successful antimycotic activity potentiation when combining AsExt and AgNPs.


Assuntos
Antifúngicos/farmacologia , Alho/química , Nanopartículas/química , Extratos Vegetais/farmacologia , Prata/farmacologia , Trichophyton/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/isolamento & purificação , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Prata/química , Relação Estrutura-Atividade
6.
J Cross Cult Gerontol ; 34(4): 439-459, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31691072

RESUMO

BACKGROUND: The aims of this paper are to present the evolutionary development of the Community Model of Healthy Aging (CMHA) and to show the main results of the community gerontology studies framed in each of the stages of the CMHA. METHOD: The study employs a qualitative community-based participatory research approach. We also measured several biochemical parameters, social support networks, and indicators of physical and cognitive functioning. RESULTS: We identified three stages in the development of the CMHA. The first stage was informative (CMHA-I, 1994-2000) with more than 70% of the older adults participating in self-care programs for health. The second stage was formative (CMHA-F, 2001-2015) with more than 80% of older adults participating in self-care, mutual aid, and self-management programs. The third stage was emancipatory (CMHA-E, 2016-2018). In this last stage, we added resilience and generativity as basic elements to strengthen and enhance human capacities during aging, and more than 90% of older adults made optimal use of social support networks as a key strategy. CONCLUSION: Our findings suggest that the addition of resilience and generativity in the CMHA contributed to the active participation of older adults in the maintenance of functioning and the prevention and control of diseases linked to aging.


Assuntos
Participação da Comunidade , Geriatria , Envelhecimento Saudável/psicologia , Relação entre Gerações/etnologia , Resiliência Psicológica , Idoso , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Autocuidado , Apoio Social
7.
Biochem Soc Trans ; 45(1): 237-249, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28202678

RESUMO

In the 30 years, since the discovery of nucleocytoplasmic glycosylation, O-GlcNAc has been implicated in regulating cellular processes as diverse as protein folding, localization, degradation, activity, post-translational modifications, and interactions. The cell co-ordinates these molecular events, on thousands of cellular proteins, in concert with environmental and physiological cues to fine-tune epigenetics, transcription, translation, signal transduction, cell cycle, and metabolism. The cellular stress response is no exception: diverse forms of injury result in dynamic changes to the O-GlcNAc subproteome that promote survival. In this review, we discuss the biosynthesis of O-GlcNAc, the mechanisms by which O-GlcNAc promotes cytoprotection, and the clinical significance of these data.


Assuntos
Acetilglucosamina/metabolismo , Adaptação Fisiológica/fisiologia , Processamento de Proteína Pós-Traducional , Transdução de Sinais/fisiologia , Estresse Fisiológico/fisiologia , Animais , Sobrevivência Celular , Glicosilação , Humanos , Modelos Biológicos
8.
Int J Mol Sci ; 18(7)2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28714882

RESUMO

Sphingolipids are characterized by a broad range of bioactive properties. Particularly, the development of insulin resistance, a major pathophysiological hallmark of Type 2 Diabetes mellitus (T2D), has been linked to ceramide signaling. Since vitamin D supplementation may slow down T2D progression by improving glucose concentrations and insulin sensitivity, we investigated whether vitamin D supplementation impacts on plasma sphingolipid levels in T2D patients. Thus, plasma samples of 59 patients with non-insulin-requiring T2D from a placebo-controlled, randomized, and double-blind study were retrospectively analyzed. Once per week, patients received either 20 drops of Vigantol oil, corresponding to a daily dose of 1904 IU/d vitamin D (verum: n = 31), or a placebo oil consisting of medium chain triglycerides (placebo: n = 28). Blood samples were taken from all of the participants at three different time points: 1) at the beginning of the study (baseline), 2) after 6 months supplementation, and 3) after an additional 6 months of follow-up. Plasma sphingolipids were measured by high-performance liquid chromatography tandem mass spectrometry. At baseline and 6 months follow-up, no significant differences in plasma sphingolipid species were detected between the placebo and verum groups. After 6 months, vitamin D supplementation significantly enhanced plasma C18dihydroceramide (dhCer; N-stearoyl-sphinganine (d18:0/18:0)) and C18ceramide (Cer; N-stearoyl-sphingosine (d18:1/18:0)) levels were observed in the verum group compared to the placebo group. This was accompanied by significantly higher 25-hydroxyvitamin D3 (25(OH)D3) blood levels in patients receiving vitamin D compared to the placebo group. Taken together, vitamin D supplementation induced changes of the C18 chain-length-specific dhCer and Cer plasma levels in patients with T2D. The regulation of sphingolipid signaling by vitamin D may thus unravel a novel mechanism by which vitamin D can influence glucose utilization and insulin action. Whether this acts favorably or unfavorably for the progression of T2D needs to be clarified.


Assuntos
Ceramidas/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Suplementos Nutricionais , Vitamina D/uso terapêutico , Feminino , Humanos , Lisofosfolipídeos/sangue , Masculino , Pessoa de Meia-Idade , Esfingosina/análogos & derivados , Esfingosina/sangue
9.
J Immunol ; 193(5): 2118-26, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25063864

RESUMO

The mechanisms behind destruction of the adrenal glands in autoimmune Addison's disease remain unclear. Autoantibodies against steroid 21-hydroxylase, an intracellular key enzyme of the adrenal cortex, are found in >90% of patients, but these autoantibodies are not thought to mediate the disease. In this article, we demonstrate highly frequent 21-hydroxylase-specific T cells detectable in 20 patients with Addison's disease. Using overlapping 18-aa peptides spanning the full length of 21-hydroxylase, we identified immunodominant CD8(+) and CD4(+) T cell responses in a large proportion of Addison's patients both ex vivo and after in vitro culture of PBLs ≤20 y after diagnosis. In a large proportion of patients, CD8(+) and CD4(+) 21-hydroxylase-specific T cells were very abundant and detectable in ex vivo assays. HLA class I tetramer-guided isolation of 21-hydroxylase-specific CD8(+) T cells showed their ability to lyse 21-hydroxylase-positive target cells, consistent with a potential mechanism for disease pathogenesis. These data indicate that strong CTL responses to 21-hydroxylase often occur in vivo, and that reactive CTLs have substantial proliferative and cytolytic potential. These results have implications for earlier diagnosis of adrenal failure and ultimately a potential target for therapeutic intervention and induction of immunity against adrenal cortex cancer.


Assuntos
Doença de Addison/imunologia , Linfócitos T CD8-Positivos/imunologia , Proliferação de Células , Imunidade Celular , Peptídeos/imunologia , Esteroide 21-Hidroxilase/imunologia , Doença de Addison/patologia , Adolescente , Neoplasias do Córtex Suprarrenal/imunologia , Neoplasias do Córtex Suprarrenal/patologia , Adulto , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/patologia , Humanos , Pessoa de Meia-Idade
10.
Proteomics ; 15(2-3): 591-607, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25263469

RESUMO

The modification of intracellular proteins by monosaccharides of O-linked ß-N-acetylglucosamine (O-GlcNAc) is an essential and dynamic PTM of metazoans. The addition and removal of O-GlcNAc is catalyzed by the O-GlcNAc transferase (OGT) and O-GlcNAcase, respectively. One mechanism by which O-GlcNAc is thought to mediate proteins is by regulating phosphorylation. To provide insight into the pathways regulated by O-GlcNAc, we have utilized SILAC-based quantitative proteomics to carry out comparisons of site-specific phosphorylation in OGT wild-type and Null cells. Quantitation of the phosphoproteome demonstrated that of 5529 phosphoserine, phosphothreonine, and phosphotyrosine sites, 232 phosphosites were upregulated and 133 downregulated in the absence of O-GlcNAc. Collectively, these data suggest that deletion of OGT has a profound effect on the phosphorylation of cell cycle and DNA damage response proteins. Key events were confirmed by biochemical analyses and demonstrate an increase in the activating autophosphorylation event on ATM (Ser1987) and on ATM's downstream targets p53, H2AX, and Chk2. Together, these data support widespread changes in the phosphoproteome upon removal of O-GlcNAc, suggesting that O-GlcNAc regulates processes such as the cell cycle, genomic stability, and lysosomal biogenesis. All MS data have been deposited in the ProteomeXchange with identifier PXD001153 (http://proteomecentral.proteomexchange.org/dataset/PXD001153).


Assuntos
Dano ao DNA , N-Acetilglucosaminiltransferases/metabolismo , Fosfopeptídeos/análise , Proteínas/metabolismo , Transdução de Sinais , Acetilglucosamina/metabolismo , Sequência de Aminoácidos , Ciclo Celular , Linhagem Celular , Deleção de Genes , Glicosilação , Humanos , Dados de Sequência Molecular , N-Acetilglucosaminiltransferases/genética , Fosfopeptídeos/metabolismo , Fosforilação , Proteínas/química , Proteômica , Espectrometria de Massas em Tandem
11.
Am J Physiol Lung Cell Mol Physiol ; 306(5): L397-404, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24414255

RESUMO

The factors that contribute to pulmonary embolism (PE), a potentially fatal complication of deep vein thrombosis (DVT), remain poorly understood. Whereas fibrin clot structure and functional properties have been implicated in the pathology of venous thromboembolism and the risk for cardiovascular complications, their significance in PE remains uncertain. Therefore, we systematically compared and quantified clot formation and lysis time, plasminogen levels, viscoelastic properties, activated factor XIII cross-linking, and fibrin clot structure in isolated DVT and PE subjects. Clots made from plasma of PE subjects showed faster clot lysis times with no differences in lag time, rate of clot formation, or maximum absorbance of turbidity compared with DVT. Differences in lysis times were not due to alterations in plasminogen levels. Compared with DVT, clots derived from PE subjects showed accelerated establishment of viscoelastic properties, documented by a decrease in lag time and an increase in the rate of viscoelastic property formation. The rate and extent of fibrin cross-linking by activated factor XIII were similar between clots from DVT and PE subjects. Electron microscopy revealed that plasma fibrin clots from PE subjects exhibited lower fiber density compared with those from DVT subjects. These data suggest that clot structure and functional properties differ between DVT and PE subjects and provide insights into mechanisms that may regulate embolization.


Assuntos
Coagulação Sanguínea/fisiologia , Fibrina/química , Fibrina/metabolismo , Fibrinólise/fisiologia , Embolia Pulmonar/metabolismo , Adulto , Idoso , Reagentes de Ligações Cruzadas/metabolismo , Elasticidade , Fator XIIIa/metabolismo , Feminino , Fibrina/ultraestrutura , Fibrinogênio/metabolismo , Humanos , Masculino , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Plasminogênio/metabolismo , Estudos Prospectivos , Embolia Pulmonar/etiologia , Trombose Venosa/complicações
12.
Nanoscale Horiz ; 9(2): 278-284, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38044846

RESUMO

High-performance semiconductor materials and devices are needed to supply the growing energy and computing demand. Organic semiconductors (OSCs) are attractive options for opto-electronic devices, due to their low cost, extensive tunability, easy fabrication, and flexibility. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been extensively studied due to their high carrier mobility, stability and opto-electronic tunability. Although molecular charge transfer doping affords widely tunable carrier density and conductivity in s-SWCNTs (and OSCs in general), a pervasive challenge for such systems is reliable measurement of charge carrier density and mobility. In this work we demonstrate a direct quantification of charge carrier density, and by extension carrier mobility, in chemically doped s-SWCNTs by a nuclear magnetic resonance approach. The experimental results are verified by a phase-space filling doping model, and we suggest this approach should be broadly applicable for OSCs. Our results show that hole mobility in doped s-SWCNT networks increases with increasing charge carrier density, a finding that is contrary to that expected for mobility limited by ionized impurity scattering. We discuss the implications of this important finding for additional tunability and applicability of s-SWCNT and OSC devices.

13.
Circulation ; 126(20): 2392-401, 2012 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-23081989

RESUMO

BACKGROUND: Several lines of evidence support a pathophysiological role of immunity in atherosclerosis. Tyrosine-nitrated proteins, a footprint of oxygen- and nitrogen-derived oxidants generated by cells of the immune system, are enriched in atheromatous lesions and in circulation of patients with coronary artery disease (CAD). However, the consequences of possible immune reactions triggered by the presence of nitrated proteins in subjects with clinically documented atherosclerosis have not been explored. METHODS AND RESULTS: Specific immunoglobulins that recognize 3-nitrotyrosine epitopes were identified in human lesions, as well as in circulation of patients with CAD. The levels of circulating immunoglobulins against 3-nitrotyrosine epitopes were quantified in patients with CAD (n=374) and subjects without CAD (non-CAD controls, n=313). A 10-fold increase in the mean level of circulating immunoglobulins against protein-bound 3-nitrotyrosine was documented in patients with CAD (3.75±1.8 µg antibody Eq/mL plasma versus 0.36±0.8 µg antibody Eq/mL plasma), and was strongly associated with angiographic evidence of significant CAD. CONCLUSIONS: The results of this cross-sectional study suggest that posttranslational modification of proteins via nitration within atherosclerotic plaque-laden arteries and in circulation serve as neo-epitopes for the elaboration of immunoglobulins, thereby providing an association between oxidant production and the activation of the immune system in CAD.


Assuntos
Doença da Artéria Coronariana/imunologia , Epitopos/imunologia , Imunoglobulinas/sangue , Tirosina/análogos & derivados , Idoso , Estudos de Casos e Controles , Angiografia Coronária , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Estudos Transversais , Feminino , Humanos , Sistema Imunitário/fisiopatologia , Masculino , Pessoa de Meia-Idade , Tirosina/imunologia
14.
ACS Nano ; 17(15): 14916-14929, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37494884

RESUMO

Controlling the binding of functional organic molecules on quantum dot (QD) surfaces and the resulting ligand/QD interfacial structure determines the resulting organic-inorganic hybrid behavior. In this study, we vary the binding of tetracenedicarboxylate ligands bound to PbS QDs cast in thin films by performing solid-state ligand exchange of as-produced bound oleate ligands. We employ comprehensive Fourier-transform infrared (FTIR) analysis coupled with ultraviolet-visible (UV-vis) spectrophotometric measurements, transient absorption, and Density Functional Theory (DFT) simulations to study the QD/ligand surface structure and resulting optoelectronic properties. We find that there are three primary QD/diacid structures, each with a distinct binding mode dictated by the QD-ligand and ligand-ligand intermolecular and steric interactions. They can be accessed nearly independently of one another via different input ligand concentrations. Low concentrations produce mixed oleate/tetracene ligand structures where the tetracene carboxylates tilt toward QD surfaces. Intermediate concentrations produce mixed oleate/tetracene ligand structures with ligand-ligand interactions through intramolecular hydrogen bonding with the ligands perpendicular to the QD surface and weaker QD/ligand electronic interactions. High concentrations result in full ligand exchange, and the ligands tilt toward the surface while the QD film compacts. When the tetracene ligands tilt or lie flat on the QD surface, the benzene ring π-system interacts strongly with the p-orbitals at the PbS surface and produces strong QD-ligand interactions evidenced through QD/ligand state mixing, with a coupling energy of ≈700 meV.

15.
Cureus ; 15(7): e41696, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37575726

RESUMO

With the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the Centers for Disease Control and Prevention (CDC) authorized the third dose of the Pfizer-BioNTech (BNT162b2) vaccine with the rationale for prolonged elevation of anti-SARS-CoV-2 antibody titers and protection against the SARS-CoV-2 virus. To better understand how administration of the third dose of the Pfizer/BioNTech coronavirus disease 2019 (COVID-19) vaccine affects the incidence and severity of SARS-CoV-2 infections, we administered the third dose of the Pfizer-BioNTech (BNT162b2) to 189 participants. Blood samples were collected from participants during each of their scheduled visits (baseline, week two, week 12, and week 24) and tested for semi-quantitative anti-SARS-CoV-2 immunoglobulin G (IgG) titers. Our results showed that administration of the third dose of the Pfizer-BioNTech (BNT162b2) vaccine elicited elevated anti-SARS-CoV-2 IgG antibodies for the 24-week duration of the study. IgG antibody titers were greatest in week two, and progressively decreased by week 12 and week 24, with statistically significant differences between the IgG antibody titers for each collection date.

16.
Curr Diab Rep ; 12(6): 635-42, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22976537

RESUMO

Vitamin D is a secosteroid hormone that resembles other nuclear steroid hormones such as thyroid, gluco-, and mineralocorticoids, as well as gonadal effector systems. Primarily understood as a master regulator of bone and calcium/phosphate physiology, it is now increasingly recognized as orchestrating numerous aspects of cell growth and differentiation in many tissues, including those of innate and acquired immunity. This review addresses recently discovered aspects that highlight vitamin D's potential for immune intervention and how the vitamin D pathway is utilized for anti-infective and antineoplastic immunity. This provides the rationale for novel therapeutic strategies in the context both of prevention and of therapy of immune dysregulation in type 1 diabetes.


Assuntos
Imunidade Adaptativa/imunologia , Diabetes Mellitus Tipo 1/imunologia , Tolerância Imunológica , Imunidade Inata/imunologia , Deficiência de Vitamina D/imunologia , Vitamina D/imunologia , Imunidade Adaptativa/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/fisiopatologia , Suplementos Nutricionais , Feminino , Humanos , Masculino , Deficiência de Vitamina D/genética , Deficiência de Vitamina D/fisiopatologia
17.
Eur J Endocrinol ; 184(3): 373-381, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33444227

RESUMO

OBJECTIVE: While vitamin D regulates immune cells, little is known about it in autoimmune Addison's disease (AAD). We investigated the vitamin D status in AAD patients from five European populations to assess its deficiency. In addition, we studied two case-control cohorts for vitamin D metabolism and pathway genes. DESIGN: Cross-sectional study. METHODS: A total of 1028 patients with AAD from Germany (n = 239), Italy (n = 328), Norway (n = 378), UK (n = 44) and Poland (n = 39) and 679 controls from Germany (n = 301) and Norway (n = 378) were studied for 25(OH)D3 (primary objective). Secondary objectives (1,25(OH)2D3 and pathway genes) were examined in case-controls from Germany and Norway correlating 25(OH)D3 and single nucleotide polymorphisms within genes encoding the vitamin D receptor (VDR), 1-α-hydroxylase (CYP27B1), 25-hydroxylase (CYP2R1), 24-hydroxylase (CYP24A1) and vitamin D binding protein (GC/DBP). RESULTS: Vitamin D deficiency (25(OH)D3 10-20 ng/mL) was highly prevalent in AAD patients (34-57%), 5-22% were severely deficient (<10 ng/mL), 28-38% insufficient (20-30 ng/mL) and only 7-14% sufficient (>30 ng/mL). Lower 25(OH)D3 and 1,25(OH)2D3 levels were observed both in Norwegian and German AAD (P = 0.03/0.003 and P = 1 × 10-5/< 1 × 10-7, respectively) the former was associated with CYP2R1 (rs1553006) genotype G. Whereas controls achieved sufficient median 25(OH)D3 in summers (21.4 to 21.9 ng/mL), AAD patients remained largely deficient (18.0 to 21.2 ng/mL) and synthesize less 1,25(OH)2D3. CONCLUSION: Vitamin D deficiency and insufficiency are highly prevalent in AAD patients. The vitamin D status of AAD may be influenced by genetic factors and suggests individual vitamin D requirements throughout the year.


Assuntos
Doença de Addison/complicações , Calcifediol/sangue , Genótipo , Polimorfismo de Nucleotídeo Único , Deficiência de Vitamina D/complicações , Doença de Addison/sangue , Doença de Addison/genética , Adulto , Calcitriol/sangue , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Receptores de Calcitriol/genética , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/genética , Proteína de Ligação a Vitamina D/genética , Vitamina D3 24-Hidroxilase/genética
18.
Front Immunol ; 11: 583709, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33365026

RESUMO

Context: Autoimmune polyglandular syndrome (APS-2: autoimmune Addison's disease or type 1 diabetes) is conferred by predisposing HLA molecules, vitamin D deficiency, and heritable susceptibility. Organ destruction is accompanied by cytokine alterations. We addressed the monocytic cytokines of two distinct APS-2 cohorts, effects of vitamin D and HLA DQ risk. Methods: APS-2 patients (n = 30) and healthy controls (n = 30) were genotyped for HLA DQA1/DQB1 and their CD14+ monocytes stimulated with IL1ß and/or 1,25(OH)2D3 for 24 h. Immune regulatory molecules (IL-6, IL-10, IL-23A, IL-15, CCL-2, PD-L1), vitamin D pathway gene transcripts (CYP24A1, CYP27B1, VDR), and CD14 were analyzed by enzyme-linked immunosorbent assay and RTqPCR. Results: Pro-inflammatory CCL-2 was higher in APS-2 patients than in controls (p = 0.001), whereas IL-6 showed a trend - (p = 0.1). In vitro treatment with 1,25(OH)2D3 reduced proinflammatory cytokines (IL-6, CCL-2, IL-23A, IL-15) whereas anti-inflammatory cytokines (IL-10 and PD-L1) rose both in APS-type 1 diabetes and APS-Addison´s disease. Patients with adrenal autoimmunity showed a stronger response to vitamin D. Expression of IL-23A and vitamin D pathway genes VDR and CYP27B1 varied by HLA genotype and was lower in healthy individuals with high-risk HLA (p = 0.0025; p = 0.04), while healthy controls with low-risk HLA showed a stronger IL-10 and CD14 expression (p = 0.01; p = 0.03). Conclusion: 1,25(OH)2D3 regulates the monocytic response in APS-2 disorders type 1 diabetes or Addison´s disease. The monocytic cytokine profile of individuals carrying HLA high-risk alleles is proinflammatory, enhances polyglandular autoimmunity and can be targeted by vitamin D.


Assuntos
Citocinas/imunologia , Antígenos HLA-DQ/imunologia , Monócitos/imunologia , Poliendocrinopatias Autoimunes/imunologia , Vitamina D/imunologia , Adulto , Alelos , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Inflamação/imunologia , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/imunologia
19.
BMC Med Genet ; 10: 126, 2009 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-19961590

RESUMO

BACKGROUND: Three genes have been confirmed as major joint susceptibility genes for endocrine autoimmune disease:human leukocyte antigen class II, cytotoxic T-lymphocyte antigen 4 and protein tyrosine phosphatase non-receptor type 22. Recent studies showed that a genetic variation within the interferon induced helicase domain 1 (IFIH1) locus (rs1990760 polymorphism) is an additional risk factor in type 1 diabetes and Graves' disease (GD). METHODS: The aim of the present study was to investigate the role of the rs1990760 polymorphism within the IFIH1 gene in German patients with GD (n = 258), Hashimoto's thyroiditis (HT, n = 106), Addison's disease (AD, n = 195) and healthy controls (HC, n = 227) as well as in 55 GD families (165 individuals, German) and 100 HT families (300 individuals, Italian). Furthermore, the interaction between rs1990760 polymorphism with human leukocyte antigen (HLA) risk haplotype DQ2(DQA*0501-DQB*0201), the risk haplotypes DQ2/DQ8 (DQA*0301-DQB*0302) and the status of thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb) and TSH receptor antibody (TRAb) in patients and families were analysed. RESULTS: No significant differences were found between the allele and genotype frequencies for rs1990760 IFIH1 polymorphism in patients with GD, HT, AD and HC. Also no differences were observed when stratifying the IFIH1 rs1990760 polymorphism for gender, presence or absence of thyroid antibodies (GD:TRAb and HT:TPOAb/TgAb) and HLA risk haplotypes (DQ2:for GD and HT, DQ2/DQ8:for AD). Furthermore the transmission analysis in GD and HT families revealed no differences in alleles transmission for rs1990760 IFIH1 from parents with or without HLA risk haplotype DQ2 to the affected offspring. In contrast, by dividing the HT parents according to the presence or absence of thyroid Ab titers, mothers and fathers both positive for TPOAb/TgAb overtransmitted the allele A of IFIH1 rs1990760 to their HT affected offspring (61.8% vs 38.2%;p = 0.05;corrected p [pc] = 0.1). However, these associations did not remain statistically significant after correction of the p-values. CONCLUSION: In conclusion, our data suggest, no contribution from IFIH1 rs1990760 polymorphism to the pathogenesis of either Graves' disease, Hashimoto's thyroiditis or Addison's disease in our study populations. However, in order to exclude a possible influence of the studied polymorphism in specified subgroups within patients with autoimmune thyroid disease, further investigations in larger populations are needed.


Assuntos
Doença de Addison/genética , RNA Helicases DEAD-box/genética , Doença de Graves/genética , Doença de Hashimoto/genética , Polimorfismo Genético , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Criança , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Helicase IFIH1 Induzida por Interferon , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
J Steroid Biochem Mol Biol ; 187: 52-57, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30521849

RESUMO

The arachidonate 5-lipoxygenase (ALOX5) pathway has been implicated in chronic inflammatory disease which may be influenced by vitamin D due to vitamin D response elements (VDRE). We investigated an ALOX5 polymorphism (rs4987105) in patients with type 2 diabetes (T2D) and the in vitro effects of calcitriol (1,25(OH)2D3) on ALOX5 metabolism in monocytes of T2D patients and healthy controls (HC). 533 T2D and 473 HC were genotyped for the rs4987105 polymorphism. In addition, the 25(OH)D3 and 1,25(OH)2D3 plasma levels were measured in both cohorts. Further C-reactive protein (CRP) was determined in T2D patients. Our results demonstrate, that genotype CC and the allele C of ALOX5 rs4987105 polymorphism were more frequent in T2D compared to HC (OR = 1.44; 95% CI: 1.12-1.84; p < 0.05). Lower levels of both vitamin D metabolites (p < 0.0001 respectively) were found in the CC genotyped T2D patients compared to CC genotyped HC. In addition, CC genotyped T2D patients had higher levels of CRP compared to CT and TT genotyped T2D patients, (p < 0.01). In order to evaluate the impact of calcitriol in primary isolated monocytes, we isolated monocytes of 20 T2D patients and 20 HC. The cells were treated with 1,25(OH)2D3 and interleukin-1beta (IL-1ß) for 24 h. The following genes were analysed for expression changes: ALOX5, leukotriene A4 hydrolase (LTA4H), leukotriene B4 receptor type 1 (LTB4R1) and CD14. Treatment with IL-1ß+1,25(OH)2D3 increased ALOX5, LTA4H and LTB4R1 and CD14 mRNA in both T2D patients and HC (p < 0.0001, respectively). In addition, IL-1ß+1,25(OH)2D3 treatment led to higher ALOX5, LTA4H and CD14 mRNA levels in T2D patients compared to HC (p < 0.001, p < 0.05, p ≤ 0.05, respectively). In conclusion, ALOX5 rs4987105 allele C confers susceptibility to T2D, lower vitamin D metabolites and higher CRP levels complement this association. Additionally, IL-1ß+1,25(OH)2D3 treatment on, ALOX5, LTA4H and CD14 mRNA indicate a diabetes specific modulation. These findings identify a novel pathway in T2D potentially amenable for individualized therapeutic targeting.


Assuntos
Araquidonato 5-Lipoxigenase/genética , Calcitriol/uso terapêutico , Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleotídeo Único , Vitaminas/uso terapêutico , Proteína C-Reativa/análise , Células Cultivadas , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Predisposição Genética para Doença , Genótipo , Humanos , Interleucina-1beta/uso terapêutico , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Regulação para Cima/efeitos dos fármacos , Vitamina D/sangue
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