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1.
Physiol Rev ; 103(3): 1965-2038, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36796099

RESUMO

Pregnancy is established during the periconceptional period as a continuum beginning with blastocyst attachment to the endometrial epithelial surface followed by embryo invasion and placenta formation. This period sets the foundation for the child and mother's health during pregnancy. Emerging evidence indicates that prevention of downstream pathologies in both the embryo/newborn and pregnant mother may be possible at this stage. In this review, we discuss current advances in the periconceptional space, including the preimplantation human embryo and maternal endometrium. We also discuss the role of the maternal decidua, the periconceptional maternal-embryonic interface, the dialogue between these elements, and the importance of the endometrial microbiome in the implantation process and pregnancy. Finally, we discuss the myometrium in the periconceptional space and review its role in determining pregnancy health.


Assuntos
Implantação do Embrião , Endométrio , Gravidez , Feminino , Criança , Recém-Nascido , Humanos , Blastocisto , Placenta
2.
J Exp Bot ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38808567

RESUMO

Hydrogen sulfide regulates essential plant processes, including adaptation responses to stress situations, and the best characterized mechanism of action of sulfide consists of the posttranslational modification of persulfidation. In this study, we reveal the first persulfidation proteome described in rice including 3443 different persulfidated proteins that participate in a broad range of biological processes and metabolic pathways. In addition, comparative proteomics revealed specific proteins involved in sulfide signaling during drought responses. Several proteins involved in the maintenance of cellular redox homeostasis, the TCA cycle and energy-related pathways, and ion transmembrane transport and cellular water homeostasis, highlighting the aquaporin family, showed the highest differential levels of persulfidation. We revealed that water transport activity is regulated by sulfide which correlates to an increasing level of persulfidation of aquaporins. Our findings emphasize the impact of persulfidation on total ATP levels, fatty acid composition, ROS levels, antioxidant enzymatic activities, and relative water content. Interestingly, the persulfidation role on aquaporin transport activity as an adaptation response in rice differs from the current knowledge in Arabidopsis, which emphasizes the distinct role of sulfide improving rice tolerance to drought.

3.
Vet Res ; 55(1): 71, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822398

RESUMO

In the wake of the COVID-19 pandemic caused by SARS-CoV-2, questions emerged about the potential effects of Bacillus Calmette-Guérin (BCG) vaccine on the immune response to SARS-CoV-2 infection, including the neurodegenerative diseases it may contribute to. To explore this, an experimental study was carried out in BCG-stimulated and non-stimulated k18-hACE2 mice challenged with SARS-CoV-2. Viral loads in tissues determined by RT-qPCR, histopathology in brain and lungs, immunohistochemical study in brain (IHC) as well as mortality rates, clinical signs and plasma inflammatory and coagulation biomarkers were assessed. Our results showed BCG-SARS-CoV-2 challenged mice presented higher viral loads in the brain and an increased frequency of neuroinvasion, with the greatest differences observed between groups at 3-4 days post-infection (dpi). Histopathological examination showed a higher severity of brain lesions in BCG-SARS-CoV-2 challenged mice, mainly consisting of neuroinflammation, increased glial cell population and neuronal degeneration, from 5 dpi onwards. This group also presented higher interstitial pneumonia and vascular thrombosis in lungs (3-4 dpi), BCG-SARS-CoV-2 mice showed higher values for TNF-α and D-dimer values, while iNOS values were higher in SARS-CoV-2 mice at 3-4 dpi. Results presented in this study indicate that BCG stimulation could have intensified the inflammatory and neurodegenerative lesions promoting virus neuroinvasion and dissemination in this experimental model. Although k18-hACE2 mice show higher hACE2 expression and neurodissemination, this study suggests that, although the benefits of BCG on enhancing heterologous protection against pathogens and tumour cells have been broadly demonstrated, potential adverse outcomes due to the non-specific effects of BCG should be considered.


Assuntos
Vacina BCG , Encéfalo , COVID-19 , SARS-CoV-2 , Animais , Camundongos , Vacina BCG/administração & dosagem , COVID-19/imunologia , COVID-19/virologia , SARS-CoV-2/fisiologia , Encéfalo/patologia , Encéfalo/virologia , Carga Viral , Pulmão/patologia , Pulmão/virologia , Pulmão/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Camundongos Transgênicos , Feminino
4.
J Org Chem ; 89(6): 4042-4055, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38438277

RESUMO

Recent years have witnessed an increasing interest in the synthesis and study of BODIPY-glycoconjugates. Most of the described synthetic methods toward these derivatives involve postfunctional modifications of the BODIPY core followed by the covalent attachment of the fluorophore and the carbohydrate through a "connector". Conversely, few de novo synthetic approaches to linker-free carbohydrate-BODIPY hybrids have been described. We have developed a reliable modular, de novo, synthetic strategy to linker-free BODIPY-sugar derivatives using the condensation of pyrrole C-glycosides with a pyrrole-carbaldehyde derivative mediated by POCl3. This methodology allows labeling of carbohydrate biomolecules with fluorescent-enough BODIPYs within the biological window, stable in aqueous media, and able to display singlet oxygen generation.


Assuntos
Compostos de Boro , Glicosídeos , Pirróis
5.
Plant Cell ; 32(12): 3902-3920, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33037147

RESUMO

Hydrogen sulfide is a signaling molecule that regulates essential processes in plants, such as autophagy. In Arabidopsis (Arabidopsis thaliana), hydrogen sulfide negatively regulates autophagy independently of reactive oxygen species via an unknown mechanism. Comparative and quantitative proteomic analysis was used to detect abscisic acid-triggered persulfidation that reveals a main role in the control of autophagy mediated by the autophagy-related (ATG) Cys protease AtATG4a. This protease undergoes specific persulfidation of Cys170 that is a part of the characteristic catalytic Cys-His-Asp triad of Cys proteases. Regulation of the ATG4 activity by persulfidation was tested in a heterologous assay using the Chlamydomonas reinhardtii CrATG8 protein as a substrate. Sulfide significantly and reversibly inactivates AtATG4a. The biological significance of the reversible inhibition of the ATG4 by sulfide is supported by the results obtained in Arabidopsis leaves under basal and autophagy-activating conditions. A significant increase in the overall ATG4 proteolytic activity in Arabidopsis was detected under nitrogen starvation and osmotic stress and can be inhibited by sulfide. Therefore, the data strongly suggest that the negative regulation of autophagy by sulfide is mediated by specific persulfidation of the ATG4 protease.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas Relacionadas à Autofagia/metabolismo , Cisteína Proteases/metabolismo , Proteômica , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Autofagia , Proteínas Relacionadas à Autofagia/genética , Cisteína Proteases/genética , Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Sulfetos/metabolismo
6.
Audiol Neurootol ; 28(3): 230-238, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36731442

RESUMO

INTRODUCTION: This study aimed to evaluate the incidence of balance disorders and the efficacy of dexamethasone in protecting patients undergoing cisplatin-based cancer treatment against vestibulototoxicity. METHODS: This study was a randomized controlled phase IIIB clinical trial. The subjects participating in the clinical trial were patients with a neoplastic disease whose treatment protocol included cisplatin. The average dose of cisplatin was 444.87 mg (SD 235.2 mg). Treatment consisted of intratympanically administering dexamethasone via a passive diffusion device called Microwick (8 mg/24 h dose) from the start of treatment with cisplatin to 3 weeks after the last cycle. Patients were administered the medication to one ear, and the contralateral ear was used as the control. The treated ears were randomly chosen using a computer system (randomization). Vestibular system was evaluated by video head impulse test before each cisplatin cycle. RESULTS: Thirty-four patients were recruited over a 2-year period at a reference tertiary hospital, of whom 11 were excluded. Forty-six ears were analyzed (23 treated and 23 control ears). Vestibular analysis presented no changes in the mean increase in the vestibulo-ocular response in all patients evaluated, both in treated and control ears. Both 8.69% infection complications during treatment and 34.8% permanent perforation at 6 months were detected after device removal. CONCLUSION: Ototoxicity related to cisplatin-based treatment does not affect the vestibular system. Long-term high-dose intratympanic dexamethasone treatment is safe for the vestibular system.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Cisplatino/efeitos adversos , Antineoplásicos/efeitos adversos , Dexametasona/efeitos adversos , Neoplasias/tratamento farmacológico
7.
Genes Dev ; 29(7): 702-17, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25805847

RESUMO

Stem cells can self-renew and differentiate into multiple cell types. These characteristics are maintained by the combination of specific signaling pathways and transcription factors that cooperate to establish a unique epigenetic state. Despite the broad interest of these mechanisms, the precise molecular controls by which extracellular signals organize epigenetic marks to confer multipotency remain to be uncovered. Here, we use human embryonic stem cells (hESCs) to show that the Activin-SMAD2/3 signaling pathway cooperates with the core pluripotency factor NANOG to recruit the DPY30-COMPASS histone modifiers onto key developmental genes. Functional studies demonstrate the importance of these interactions for correct histone 3 Lys4 trimethylation and also self-renewal and differentiation. Finally, genetic studies in mice show that Dpy30 is also necessary to maintain pluripotency in the pregastrulation embryo, thereby confirming the existence of similar regulations in vivo during early embryonic development. Our results reveal the mechanisms by which extracellular factors coordinate chromatin status and cell fate decisions in hESCs.


Assuntos
Ativinas/metabolismo , Diferenciação Celular/genética , Cromatina/genética , Histonas/genética , Proteínas de Homeodomínio/metabolismo , Proteína Nodal/metabolismo , Transdução de Sinais , Animais , Células Cultivadas , Cromatina/metabolismo , Embrião de Mamíferos , Células-Tronco Embrionárias , Epigênese Genética/genética , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Camundongos , Proteína Homeobox Nanog , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo
8.
J Org Chem ; 87(6): 4241-4253, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35230109

RESUMO

Bicyclic triazolium scaffolds are widely employed in N-heterocyclic carbene (NHC) organocatalysis. While the incorporation of a fused ring was initially for synthetic utility in accessing chiral, modular triazolyl scaffolds, recent results highlight the potential for impact upon reaction outcome with the underpinning origins unclear. The common first step to all triazolium-catalyzed transformations is C(3)-H deprotonation to form the triazolylidene NHC. Herein, we report an analysis of the impact of size of the fused (5-, 6-, and 7-membered, n = 1, 2, and 3, respectively) ring on the C(3) proton transfer reactions of a series of bicyclic triazolium salts. Rate constants for the deuteroxide-catalyzed C(3)-H/D-exchange of triazolium salts, kDO, were significantly influenced by the size of the adjacent fused ring, with the kinetic acidity trend, or protofugalities, following the order kDO (n = 1) > kDO (n = 2) ≈ kDO (n = 3). Detailed analyses of X-ray diffraction (XRD) data for 20 triazolium salts (including 16 new structures) and of computational data for the corresponding triazolylidene NHCs provide insight on structural effects of alteration of fused ring size. In particular, changes in internal triazolyl NCN angle and positioning of the most proximal CH2 with variation in fused ring size are proposed to influence the experimental protofugality order.

9.
Phys Chem Chem Phys ; 24(10): 5929-5938, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35195637

RESUMO

Generation of triplet states in assemblies of organic chromophores is extremely appealing for their potential use in optoelectronic applications. In this work, we investigate the intricacies of triplet state generation in an orthogonal BODIPY dimer by combining delayed photoemission techniques with electronic structure calculations. Our analysis provides a deep understanding of the electronic states involved, and describes different competing deactivation channels beyond prompt radiative decay. In particular, we identify charge-transfer (CT) mediated intersystem crossing (ISC) as the most likely mechanism for the triplet state generation in this system. The different emission bands at long times can be associated with delayed fluorescence, CT emission and phosphorescence from multiple low-energy triplets. Interestingly, the dependence of the yield of triplet state population and emission profiles with the solvent polarity evidences the decisive role of the CT configuration in the fate of the photoactivated dimer, controlling the relative ISC, reverse ISC, and internal conversion efficiencies. Overall, the present results provide a rather complete description of the delayed photophysics in the BODIPY dimer, but are not able to fully rationalize the unexpected photoluminescence recorded at long wavelengths (≥ 900 nm). We hypothesize that the origin of this emission, not present in BODIPY monomers, emerges from intermonomer interactions triggered by intramolecular distortions opening up a new vision in the controverted mechanism driving the photophysical behavior from orthogonally linked organic monomers.

10.
Phys Chem Chem Phys ; 24(44): 27441-27448, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36341868

RESUMO

We envisioned a new approach for achieving triplet-triplet annihilation-assisted photon upconversion based on the rational design of a heavy-atom-free, all-organic and photoactivatable triplet-triplet synergistic multichromophoric molecular assembly. This single molecular architecture is easily built by covalently anchoring triplet-annihilator units (pyrenes) to a triplet-photosensitizer moiety (BODIPY), to improve the effectiveness and probability of the required triplet-triplet energy transfer and the ulterior triplet-triplet annihilation. This unprecedented design takes advantage of the high synthetic accessibility and chemical versatility of the COO-BODIPY scaffold. The laser-induced photophysical characterization, assisted by computational simulations (quantum mechanics calculations at single molecular level and molecular dynamics in a solvent cage), identifies the key factors to finely control the intersystem crossing and reverse intersystem crossing probability, pivotal to improve energy transfer efficiency between the involved triplet states. Likewise, theoretical simulations highlight the relevance of the new photoactivable chromophoric design to promote intra- and inter-molecular triplet-triplet annihilation towards enhanced photon upconversion, yielding noticeable fluorescence from pyrene units even under unfavorable conditions (aerated solutions of low concentration at room temperature). The understanding of the complex dynamics sustained by this single molecular architecture could approach the next generation of chemically accessible and low-cost materials enabling fluorescence by photon upconversion mediated by triplet-triplet annihilation.


Assuntos
Fótons , Pirenos , Transferência de Energia
11.
Ear Hear ; 43(2): 676-684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34483247

RESUMO

OBJECTIVE: To determine the efficacy of long-term high-dose intratympanic dexamethasone in protecting the hearing capacity of cancer patients undergoing cisplatin-based ototoxic treatment. DESIGN: A randomized controlled phase IIIB clinical trial to evaluate the efficacy of dexamethasone in protecting against hearing loss in patients undergoing cisplatin treatment. The subjects participating in the clinical trial were patients with a neoplastic disease whose treatment protocol included cisplatin. The average dose of cisplatin was 444.87 mg (SD 235.2 mg). Treatment consisted of intratympanically administering dexamethasone via a passive diffusion device called Microwick (8 mg/24 h dose) from the start of treatment with cisplatin to 3 weeks after the last cycle. Patients were administered the medication to one ear, and the contralateral ear was used as the control. The treated ears were randomly chosen using a computer system (randomization). The hearing threshold was evaluated using pure tone audiometry before each cisplatin cycle. RESULTS: Thirty-four patients were recruited over a 2-year period at a reference tertiary hospital, of whom 11 were excluded. Forty-six ears were analyzed (23 treated and 23 control ears). When treatment was completed, the audiometric analysis showed a higher hearing threshold in the study group than in the control group. Differences were statistically significant at frequencies of 500, 1000, and 6000 Hz: 4.9 dB (1.1 to 8.7), 5.5 dB (0.8 to 10.3), and 16 dB (3.2 to 28.7), respectively, (p < 0.05, 95% confidence interval), but were not clinically significant according to the ASHA hearing loss criteria. Both 8.69% infection complications during treatment and 34.8% permanent perforation at 6 mo were detected after device removal. CONCLUSIONS: Long-term high-dose intratympanic dexamethasone treatment did not prevent cisplatin-induced hearing loss.


Assuntos
Dexametasona , Perda Auditiva , Neoplasias , Audiometria de Tons Puros , Cisplatino/efeitos adversos , Dexametasona/uso terapêutico , Perda Auditiva/induzido quimicamente , Perda Auditiva/prevenção & controle , Humanos , Neoplasias/tratamento farmacológico , Resultado do Tratamento
12.
Int J Mol Sci ; 23(1)2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35008911

RESUMO

Changes in the female genital tract microbiome are consistently correlated to gynecological and obstetrical pathologies, and tract dysbiosis can impact reproductive outcomes during fertility treatment. Nonetheless, a consensus regarding the physiological microbiome core inside the uterine cavity has not been reached due to a myriad of study limitations, such as sample size and experimental design variations, and the influence of endometrial bacterial communities on human reproduction remains debated. Understanding the healthy endometrial microbiota and how changes in its composition affect fertility would potentially allow personalized treatment through microbiome management during assisted reproductive therapies, ultimately leading to improvement of clinical outcomes. Here, we review current knowledge regarding the uterine microbiota and how it relates to human conception.


Assuntos
Endométrio/microbiologia , Fertilização/fisiologia , Microbiota , Disbiose/microbiologia , Feminino , Humanos , Gravidez , Resultado da Gravidez , Virulência
13.
Molecules ; 27(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897859

RESUMO

We performed a time-gated laser-spectroscopy study in a set of heavy-atom free single BODIPY fluorophores, supported by accurate, excited-state computational simulations of the key low-lying excited states in these chromophores. Despite the strong fluorescence of these emitters, we observed a significant fraction of time-delayed (microseconds scale) emission associated with processes that involved passage through the triplet manifold. The accuracy of the predictions of the energy arrangement and electronic nature of the low-lying singlet and triplet excited states meant that an unambiguous assignment of the main deactivation pathways, including thermally activated delayed fluorescence and/or room temperature phosphorescence, was possible. The observation of triplet state formation indicates a breakthrough in the "classic" interpretation of the photophysical properties of the renowned BODIPY and its derivatives.


Assuntos
Compostos de Boro , Corantes Fluorescentes , Compostos de Boro/química , Análise Espectral
14.
Am J Obstet Gynecol ; 224(3): 251-257, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33091407

RESUMO

Bacterial vaginosis, pelvic inflammatory disease, and endometritis are infections of the genital tract that can lead to many adverse health outcomes, including infertility. Bacterial vaginosis is characterized by a lower prevalence of lactobacilli and a higher prevalence of anaerobic bacteria, including Gardnerella vaginalis, Megasphaera spp., and Atopobium vaginae. Endometritis and pelvic inflammatory disease are caused by the ascension of pathogenic bacteria to the uterus, although the mechanisms by which they do so are unclear. Bacterial vaginosis, chronic endometritis, and pelvic inflammatory disease have been linked to infertility in retrospective and prospective trials. Similarly, the causes of bacterial vaginosis and endometritis-related infertility are likely multifactorial and stem from inflammation, immune targeting of sperm antigens, the presence of bacterial toxins, and increased risk of sexually transmitted infections. Diagnosis and treatment of bacterial vaginosis, chronic endometritis, and pelvic inflammatory disease before attempting conception may be important components of preconceptional care for symptomatic women to improve outcomes of natural and assisted reproduction.


Assuntos
Endometrite/microbiologia , Infertilidade Feminina/microbiologia , Doença Inflamatória Pélvica/microbiologia , Vaginose Bacteriana/complicações , Endometrite/diagnóstico , Endometrite/terapia , Feminino , Humanos , Infertilidade Feminina/diagnóstico , Infertilidade Feminina/terapia , Doença Inflamatória Pélvica/diagnóstico , Doença Inflamatória Pélvica/terapia
15.
J Org Chem ; 86(13): 9181-9188, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34156858

RESUMO

Novel, linker-free, BODIPY-carbohydrate derivatives containing sugar residues at positions C2 and C6 are efficiently obtained by, hitherto unreported, Ferrier-type C-glycosylation of 8-aryl-1,3,5,7-tetramethyl BODIPYs with commercially available tri-O-acetyl-d-glucal followed by saponification. This transformation, which involves the electrophilic aromatic substitution (SEAr) of the dipyrrin framework with an allylic oxocarbenium ion, provides easy access to BODIPY-carbohydrate hybrids with excellent photophysical properties and a weaker tendency to aggregate in concentrated water solutions.


Assuntos
Compostos de Boro , Água , Carboidratos , Glicosilação
16.
Phys Chem Chem Phys ; 23(19): 11191-11195, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33954326

RESUMO

Herein we detail a protocol to design dyads and triads based solely on BODIPY dyes as halogen-free singlet oxygen photosensitizers or energy transfer molecular cassettes. The conducted photonic characterization reveals the key role of the BODIPY-BODIPY linkage to finely modulate the balance between the triplet state population and fluorescence decay.

17.
J Environ Manage ; 282: 111963, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33465718

RESUMO

Pollen grains emitted by urban vegetation are the main primary biological airborne particles (PBAPs) which alter the biological quality of urban air and have a significant impact on human health. This work analyses the interactions which exist between pollen-type PBAPs, meteorological variables, and air pollutants in the urban atmosphere so that the complex relationships and trends in future scenarios of changing environmental conditions can be assessed. For this study, the 1992-2018 pollen data series from the city of Granada (southeast Spain) was used, in which the dynamics of the total pollen as well as the 8 main pollen types (Cupressaceae, Olea, Pinus, Platanus, Poaceae, Populus, Quercus and Urticaceae) were analysed. The trend analysis showed that all except Urticaceae trended upward throughout the series. Spearman's correlations with meteorological variables showed that, in general, the most influential variables on the pollen concentrations were the daily maximum temperature, relative humidity, water vapor pressure, global radiation, and insolation, with different effects on different pollen types. Parallel analysis by neural networks (ANN) confirmed these variables as the predominant ones, especially global radiation. The correlation with atmospheric pollutants revealed that ozone was the pollutant with the highest influence, although some pollen types also showed correlation with NO2, SO2, CO and PM10. The Generalized Linear Models (GLM) between pollen and pollutants also indicated O3 as the most prominent variable. These results highlight the active role that pollen-type PBAPs have on urban air quality by establishing their interactions with meteorological variables and pollutants, thereby providing information on the behaviour of pollen emissions under changing environmental conditions.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Poluentes Atmosféricos/análise , Alérgenos/análise , Cidades , Monitoramento Ambiental , Humanos , Estações do Ano , Espanha
18.
Molecules ; 26(10)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34068920

RESUMO

A convergent synthetic route to a tetrasaccharide related to PI-88, which allows the incorporation of a fluorescent BODIPY-label at the reducing-end, has been developed. The strategy, which features the use of 1,2-methyl orthoesters (MeOEs) as glycosyl donors, illustrates the usefulness of suitably-designed BODIPY dyes as glycosyl labels in synthetic strategies towards fluorescently-tagged oligosaccharides.


Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/química , Oligossacarídeos/síntese química , Coloração e Rotulagem , Antineoplásicos/química , Glicosilação , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Espectrometria de Fluorescência , Estereoisomerismo
19.
Plant Physiol ; 179(1): 107-123, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30377236

RESUMO

Hydrogen cyanide (HCN) is coproduced with ethylene in plant cells and is primarily enzymatically detoxified by the mitochondrial ß-CYANOALANINE SYNTHASE (CAS-C1). Permanent or transient depletion of CAS-C1 activity in Arabidopsis (Arabidopsis thaliana) results in physiological alterations in the plant that suggest that HCN acts as a gasotransmitter molecule. Label-free quantitative proteomic analysis of mitochondrially enriched samples isolated from the wild type and cas-c1 mutant revealed significant changes in protein content, identifying 451 proteins that are absent or less abundant in cas-c1 and 353 proteins that are only present or more abundant in cas-c1 Gene ontology classification of these proteins identified proteomic changes that explain the root hairless phenotype and the altered immune response observed in the cas-c1 mutant. The mechanism of action of cyanide as a signaling molecule was addressed using two proteomic approaches aimed at identifying the S-cyanylation of Cys as a posttranslational modification of proteins. Both the 2-imino-thiazolidine chemical method and the direct untargeted analysis of proteins using liquid chromatography-tandem mass spectrometry identified a set of 163 proteins susceptible to S-cyanylation that included SEDOHEPTULOSE 1,7-BISPHOSPHATASE (SBPase), the PEPTIDYL-PROLYL CIS-TRANS ISOMERASE 20-3 (CYP20-3), and ENOLASE2 (ENO2). In vitro analysis of these enzymes showed that S-cyanylation of SBPase Cys74, CYP20-3 Cys259, and ENO2 Cys346 residues affected their enzymatic activity. Gene Ontology classification and protein-protein interaction cluster analysis showed that S-cyanylation is involved in the regulation of primary metabolic pathways, such as glycolysis, and the Calvin and S-adenosyl-Met cycles.


Assuntos
Arabidopsis/metabolismo , Gasotransmissores/metabolismo , Cianeto de Hidrogênio/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Cromatografia Líquida , Cisteína Sintase/genética , Cisteína Sintase/metabolismo , Cisteína Sintase/fisiologia , Espectrometria de Massas , Processamento de Proteína Pós-Traducional , Proteoma , Proteômica , Transdução de Sinais
20.
Chemistry ; 26(68): 16080-16088, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-32721057

RESUMO

The search for long-lived red and NIR fluorescent dyes is challenging and hitherto scarcely reported. Herein, the viability of aza-BODIPY skeleton as a promising system for achieving thermal activated delayed fluorescent (TADF) probes emitting in this target region is demonstrated for the first time. The synthetic versatility of this scaffold allows the design of energy and charge transfer cassettes modulating the stereoelectronic properties of the energy donors, the spacer moieties and the linkage positions. Delayed emission from these architectures is recorded in the red spectral region (695-735 nm) with lifetimes longer than 100 µs in aerated solutions at room temperature. The computational-aided photophysical study under mild and hard irradiation regimes disclose the interplay between molecular structure and photonic performance to develop long-lived fluorescence red emitters through thermally activated reverse intersystem crossing. The efficient and long-lasting NIR emission of the newly synthesized aza-BODIPY systems provides a basis to develop advanced optical materials with exciting and appealing photonic response.

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