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1.
J Biomed Inform ; 154: 104649, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38697494

RESUMO

OBJECTIVE: Automated identification of eligible patients is a bottleneck of clinical research. We propose Criteria2Query (C2Q) 3.0, a system that leverages GPT-4 for the semi-automatic transformation of clinical trial eligibility criteria text into executable clinical database queries. MATERIALS AND METHODS: C2Q 3.0 integrated three GPT-4 prompts for concept extraction, SQL query generation, and reasoning. Each prompt was designed and evaluated separately. The concept extraction prompt was benchmarked against manual annotations from 20 clinical trials by two evaluators, who later also measured SQL generation accuracy and identified errors in GPT-generated SQL queries from 5 clinical trials. The reasoning prompt was assessed by three evaluators on four metrics: readability, correctness, coherence, and usefulness, using corrected SQL queries and an open-ended feedback questionnaire. RESULTS: Out of 518 concepts from 20 clinical trials, GPT-4 achieved an F1-score of 0.891 in concept extraction. For SQL generation, 29 errors spanning seven categories were detected, with logic errors being the most common (n = 10; 34.48 %). Reasoning evaluations yielded a high coherence rating, with the mean score being 4.70 but relatively lower readability, with a mean of 3.95. Mean scores of correctness and usefulness were identified as 3.97 and 4.37, respectively. CONCLUSION: GPT-4 significantly improves the accuracy of extracting clinical trial eligibility criteria concepts in C2Q 3.0. Continued research is warranted to ensure the reliability of large language models.


Assuntos
Ensaios Clínicos como Assunto , Humanos , Processamento de Linguagem Natural , Software , Seleção de Pacientes
2.
Antimicrob Agents Chemother ; 67(6): e0002223, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37162345

RESUMO

The emergence of azole-resistant and biofilm-forming Candida spp. contributes to the constantly increasing incidence of vulvovaginal candidiasis. It is imperative to explore new antifungal drugs or potential substituents, such as antimicrobial peptides, to alleviate the serious crisis caused by resistant fungi. In this study, a novel antimicrobial peptide named Scyampcin44-63 was identified in the mud crab Scylla paramamosain. Scyampcin44-63 exhibited broad-spectrum antimicrobial activity against bacteria and fungi, was particularly effective against planktonic and biofilm cells of Candida albicans, and exhibited no cytotoxicity to mammalian cells (HaCaT and RAW264.7) or mouse erythrocytes. Transcriptomic analysis revealed four potential candidacidal modes of Scyampcin44-63, including promotion of apoptosis and autophagy and inhibition of ergosterol biosynthesis and the cell cycle. Further study showed that Scyampcin44-63 caused damage to the plasma membrane and induced apoptosis and cell cycle arrest at G2/M in C. albicans. Scanning and transmission electron microscopy demonstrated that Scyampcin44-63-treated C. albicans cells were deformed with vacuolar expansion and destruction of organelles. In addition, C. albicans cells pretreated with the autophagy inhibitor 3-methyladenine significantly delayed the candidacidal effect of Scyampcin44-63, suggesting that Scyampcin44-63 might contribute to autophagic cell death. In a murine model of vulvovaginal candidiasis, the fungal burden of vaginal lavage was significantly decreased after treatment with Scyampcin44-63.


Assuntos
Braquiúros , Candidíase Vulvovaginal , Humanos , Feminino , Camundongos , Animais , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/microbiologia , Peptídeos Antimicrobianos , Modelos Animais de Doenças , Candida albicans , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Mamíferos
3.
Fish Shellfish Immunol ; 134: 108649, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36849046

RESUMO

With the antibiotics prohibition in feedstuffs worldwide, antimicrobial peptides (AMPs) are considered a more promising substitute for antibiotics to be used as feed additives, and positive results have been reported in livestock feeding studies. However, whether dietary supplementation of AMPs could promote the growth of mariculture animals such as fish and the underlying mechanism has not been elucidated yet. In the study, a recombinant AMP product of Scy-hepc was used as a dietary supplement (10 mg/kg) to feed mariculture juvenile large yellow croaker (Larimichthys crocea) with an average initial body weight (BW) of 52.9 g for 150 days. During the feeding trial, the fish fed with Scy-hepc showed a significant growth-promoting performance. Especially at 60 days after feeding, fish fed with Scy-hepc weighed approximately 23% more than the control group. It was further confirmed that the growth-related signaling pathways such as the GH-Jak2-STAT5-IGF1 growth axis, the PI3K-Akt and Erk/MAPK pathways were all activated in the liver after Scy-hepc feeding. Furthermore, a second repeated feeding trial was scheduled for 30 days using much smaller juvenile L. crocea with an average initial BW of 6.3 g, and similar positive results were observed. Further investigation revealed that the downstream effectors of the PI3K-Akt pathway, such as p70S6K and 4EBP1, were significantly phosphorylated, suggesting that Scy-hepc feeding might promote translation initiation and protein synthesis processes in the liver. Taken together, as an effector of innate immunity, AMP Scy-hepc played a role in promoting the growth of L. crocea and the underlying mechanism was associated with the activation of the GH-Jak2-STAT5-IGF1 axis, as well as the PI3K-Akt and Erk/MAPK signaling pathways.


Assuntos
Perciformes , Fator de Transcrição STAT5 , Animais , Peptídeos Antimicrobianos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Perciformes/metabolismo , Peixes/metabolismo , Antibacterianos/metabolismo , Proteínas de Peixes/metabolismo
4.
Proc Natl Acad Sci U S A ; 117(33): 20088-20099, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32732436

RESUMO

T lymphocyte motility and interaction dynamics with other immune cells are vital determinants of immune responses. Regulatory T (Treg) cells prevent autoimmune disorders by suppressing excessive lymphocyte activity, but how interstitial motility patterns of Treg cells limit neuroinflammation is not well understood. We used two-photon microscopy to elucidate the spatial organization, motility characteristics, and interactions of endogenous Treg and Th17 cells together with antigen-presenting cells (APCs) within the spinal cord leptomeninges in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Th17 cells arrive before the onset of clinical symptoms, distribute uniformly during the peak, and decline in numbers during later stages of EAE. In contrast, Treg cells arrive after Th17 cells and persist during the chronic phase. Th17 cells meander widely, interact with APCs, and exhibit cytosolic Ca2+ transients and elevated basal Ca2+ levels before the arrival of Treg cells. In contrast, Treg cells adopt a confined, repetitive-scanning motility while contacting APCs. These locally confined but highly motile Treg cells limit Th17 cells from accessing APCs and suppress Th17 cell Ca2+ signaling by a mechanism that is upstream of store-operated Ca2+ entry. Finally, Treg cell depletion increases APC numbers in the spinal cord and exaggerates ongoing neuroinflammation. Our results point to fundamental differences in motility characteristics between Th17 and Treg cells in the inflamed spinal cord and reveal three potential cellular mechanisms by which Treg cells regulate Th17 cell effector functions: reduction of APC density, limiting access of Th17 cells to APCs, and suppression of Th17 Ca2+ signaling.


Assuntos
Sinalização do Cálcio/fisiologia , Medula Espinal/metabolismo , Células Th17/metabolismo , Animais , Autoantígenos , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Proteínas de Fluorescência Verde , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Bainha de Mielina , Linfócitos T Reguladores
5.
Int J Mol Sci ; 24(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36982761

RESUMO

In the study, a new gene homologous to the known antimicrobial peptide Scygonadin was identified in mud crab Scylla paramamosain and named SCY3. The full-length sequences of cDNA and genomic DNA were determined. Similar to Scygonadin, SCY3 was dominantly expressed in the ejaculatory ducts of male crab and the spermatheca of post-mating females at mating. The mRNA expression was significantly up-regulated after stimulation by Vibrio alginolyticus, but not by Staphylococcus aureus. The recombinant protein rSCY3 had a killing effect on Micrococcus luteus and could improve the survival rate of mud crabs infected with V. alginolyticus. Further analysis showed that rSCY3 interacted with rSCY1 or rSCY2 using Surface Plasmon Resonance (SPR, a technology for detecting interactions between biomolecules using biosensor chips) and Mammalian Two-Hybrid (M2H, a way of detecting interactions between proteins in vivo). Moreover, the rSCY3 could significantly improve the sperm acrosome reaction (AR) of S. paramamosain and the results demonstrated that the binding of rSCY3, rSCY4, and rSCY5 to progesterone was a potential factor affecting the sperm AR by SCYs on. This study lays the foundation for further investigation on the molecular mechanism of SCYs involved in both immunity and physiological effects of S. paramamosain.


Assuntos
Braquiúros , Animais , Feminino , Masculino , Braquiúros/genética , Braquiúros/metabolismo , Reação Acrossômica , Sêmen , Espermatozoides , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/farmacologia , Proteínas de Artrópodes/química , Imunidade Inata/genética , Filogenia , Mamíferos
6.
Arch Biochem Biophys ; 721: 109190, 2022 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-35331713

RESUMO

BACKGROUND: Excessive oxidative stress of the inner ear as a result of high, intense noise exposure is regarded as a major mechanism underlying the development of noise-induced hearing loss (NIHL). The present study was designed to explore the effect and mechanism of activated transcription factor 3 (ATF3) in reduction/oxidation homeostasis of NIHL. METHOD: In vitro and in vivo assays were performed to investigate the functional role of ATF3 in the inner ear. Mice hearing was measured using auditory brainstem response. ATF3 short hairpin RNA (shRNA) was transfected into House Ear Institute-Organ of Corti 1 (HEI-OC1) cells to decrease ATF3 expression. Western blotting and quantitative real-time polymerase chain reaction (RT-qPCR) were performed to quantify ATF3, NRF2, HO-1 and NQO1 expression. Glutathione (GSH) assay was performed to detect intracellular GSH levels. ATF3 immunofluorescence analysis was carried out in cochlear cryosectioned samples and HEI-OC1 cells to localize ATF3 expression. Cell counting kit 8 assay and flow cytometry were performed to analyze cell viability. RESULT: ATF3 was upregulated in noise-exposed cochleae and HEI-OC1 cells treated with H2O2. NRF2 is a key factor regulated by ATF3. NRF2, HO-1, NQO1, and GSH expression was significantly downregulated in shATF3 HEI-OC1 cells. ATF3 silencing promoted reactive oxygen species accumulation and increased apoptosis and necrosis with H2O2 stimulus. CONCLUSION: ATF3 functions as an antioxidative factor by activating the NRF2/HO-1 pathway.


Assuntos
Fator 3 Ativador da Transcrição , Perda Auditiva Provocada por Ruído , Fator 2 Relacionado a NF-E2 , Fator 3 Ativador da Transcrição/metabolismo , Animais , Apoptose , Modelos Animais de Doenças , Heme Oxigenase-1 , Peróxido de Hidrogênio/farmacologia , Proteínas de Membrana , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
7.
J Exp Biol ; 225(7)2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35258623

RESUMO

Anthropogenic noise can be hazardous for the auditory system and wellbeing of animals, including humans. However, very limited information is known on how this global environmental pollutant affects auditory function and inner ear sensory receptors in early ontogeny. The zebrafish (Danio rerio) is a valuable model in hearing research, including investigations of developmental processes of the vertebrate inner ear. We tested the effects of chronic exposure to white noise in larval zebrafish on inner ear saccular sensitivity and morphology at 3 and 5 days post-fertilization (dpf), as well as on auditory-evoked swimming responses using the prepulse inhibition (PPI) paradigm at 5 dpf. Noise-exposed larvae showed a significant increase in microphonic potential thresholds at low frequencies, 100 and 200 Hz, while the PPI revealed a hypersensitization effect and a similar threshold shift at 200 Hz. Auditory sensitivity changes were accompanied by a decrease in saccular hair cell number and epithelium area. In aggregate, the results reveal noise-induced effects on inner ear structure-function in a larval fish paralleled by a decrease in auditory-evoked sensorimotor responses. More broadly, this study highlights the importance of investigating the impact of environmental noise on early development of sensory and behavioural responsiveness to acoustic stimuli.


Assuntos
Orelha Interna , Perda Auditiva Provocada por Ruído , Animais , Limiar Auditivo/fisiologia , Células Ciliadas Auditivas/fisiologia , Larva/fisiologia , Peixe-Zebra/fisiologia
8.
Environ Sci Technol ; 56(12): 8438-8448, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35652794

RESUMO

Perfluorooctane sulfonamide (PFOSA), a precursor of perfluorooctanesulfonate (PFOS), is widely used during industrial processes, though little is known about its toxicity, particularly to early life stage organisms that are generally sensitive to xenobiotic exposure. Here, following exposure to concentrations of 0.01, 0.1, 1, 10, and 100 µg/L PFOSA, transcriptional, morphological, physiological, and biochemical assays were used to evaluate the potential effects on aquatic organisms. The top Tox functions in exposed zebrafish were related to cardiac diseases predicted by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and Ingenuity Pathway Analysis (IPA) analysis. Consistent with impacts predicted by transcriptional changes, abnormal cardiac morphology, disordered heartbeat signals, as well as reduced heart rate and cardiac output were observed following the exposure of 0.1, 1, 10, or 100 µg/L PFOSA. Furthermore, these PFOSA-induced cardiac effects were either prevented or alleviated by supplementation with an aryl hydrocarbon receptor (AHR) antagonist or ahr2-morpholino knock-down, uncovering a seminal role of AHR in PFOSA-induced cardiotoxicity. Our results provide the first evidence in fish that PFOSA can impair proper heart development and function and raises concern for PFOSA analogues in the natural environment.


Assuntos
Receptores de Hidrocarboneto Arílico , Peixe-Zebra , Animais , Cardiotoxicidade/metabolismo , Embrião não Mamífero , Fluorocarbonos , Receptores de Hidrocarboneto Arílico/metabolismo , Sulfonamidas/metabolismo , Sulfonamidas/toxicidade , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
9.
Mar Drugs ; 20(10)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36286474

RESUMO

Hepcidin is widely present in many kinds of fish and is an important innate immune factor. A variety of HAMP2-type hepcidins have strong antimicrobial activity and immunomodulatory functions and are expected to be developed as substitutes for antibiotics. In this study, the antimicrobial activity of Hepc2 from Japanese seabass (Lateolabrax japonicus) (designated as LJ-hep2) was investigated using its recombinant precursor protein (rLJ-hep2) expressed in Pichia pastoris and a chemically synthesized mature peptide (LJ-hep2(66-86)). The results showed that both rLJ-hep2 and synthetic LJ-hep2(66-86) displayed broad antimicrobial spectrum with potent activity against gram-negative and gram-positive bacteria, and fungi. Especially, LJ-hep2(66-86) had stronger antimicrobial activity and exhibited potent activity against several clinically isolated multidrug-resistant bacteria, including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterococcus faecium. Moreover, LJ-hep2(66-86) exerted rapid bactericidal kinetic (killed tested bacteria within 2 h), induced significant morphological changes and promoted agglutination of E. coli, P. aeruginosa and Aeromonas hydrophila. The activity of LJ-hep2(66-86) against E. coli, P. aeruginosa and A. hydrophila was stable and remained active when heated for 30 min. In addition, LJ-hep2(66-86) exhibited no cytotoxicity to the mammalian cell line HEK293T and fish cell lines (EPC and ZF4). In vivo study showed that LJ-hep2(66-86) could improve the survival rate of marine medaka (Oryzias melastigma) by about 40% under the challenge of A. hydrophila, indicating its immunoprotective function. Taken together, both rLJ-hep2 and LJ-hep2(66-86) have good prospects to be used as potential antimicrobial agents in aquaculture and medicine in the future.


Assuntos
Hepcidinas , Oryzias , Animais , Humanos , Hepcidinas/química , Peptídeos Antimicrobianos , Escherichia coli , Células HEK293 , Bactérias , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Mamíferos
10.
Int J Mol Sci ; 23(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36362111

RESUMO

The abuse of antibiotics leads to the increase of bacterial resistance, which seriously threatens human health. Therefore, there is an urgent need to find effective alternatives to antibiotics, and antimicrobial peptides (AMPs) are the most promising antibacterial agents and have received extensive attention. In this study, a novel potential AMP was identified from the marine invertebrate Scylla paramamosain and named Spampcin. After bioinformatics analysis and AMP database prediction, four truncated peptides (Spa31, Spa22, Spa20 and Spa14) derived from Spampcin were screened, all of which showed potent antimicrobial activity with different antibacterial spectrum. Among them, Spampcin56-86 (Spa31 for short) exhibited strong bactericidal activity against a variety of clinical pathogens and could rapidly kill the tested bacteria within minutes. Further analysis of the antibacterial mechanism revealed that Spa31 disrupted the integrity of the bacterial membrane (as confirmed by scanning electron microscopy observation, NPN, and PI staining assays), leading to bacterial rupture, leakage of cellular contents (such as elevated extracellular ATP), increased ROS production, and ultimately cell death. Furthermore, Spa31 was found to interact with LPS and effectively inhibit bacterial biofilms. The antibacterial activity of Spa31 had good thermal stability, certain ion tolerance, and no obvious cytotoxicity. It is worth noting that Spa31 could significantly improve the survival rate of zebrafish Danio rerio infected with Pseudomonas aeruginosa, indicating that Spa31 played an important role in anti-infection in vivo. This study will enrich the database of marine animal AMPs and provide theoretical reference and scientific basis for the application of marine AMPs in medical fields.


Assuntos
Anti-Infecciosos , Braquiúros , Animais , Humanos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Antimicrobianos , Bactérias/metabolismo , Braquiúros/metabolismo , Testes de Sensibilidade Microbiana , Peixe-Zebra/metabolismo
11.
Int J Mol Sci ; 23(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35328805

RESUMO

Antimicrobial peptides (AMPs) identified in the reproductive system of animals have been widely studied for their antimicrobial activity, but only a few studies have focused on their physiological roles. Our previous studies have revealed the in vitro antimicrobial activity of two male gonadal AMPs, SCY2 and scyreprocin, from mud crab Scylla paramamosain. Their physiological functions, however, remain a mystery. In this study, the two AMPs were found co-localized on the sperm apical cap. Meanwhile, progesterone was confirmed to induce acrosome reaction (AR) of mud crab sperm in vitro, which intrigued us to explore the roles of the AMPs and progesterone in AR. Results showed that the specific antibody blockade of scyreprocin inhibited the progesterone-induced AR without affecting intracellular Ca2+ homeostasis, while the blockade of SCY2 hindered the influx of Ca2+. We further showed that SCY2 could directly bind to Ca2+. Moreover, progesterone failed to induce AR when either scyreprocin or SCY2 function was deprived. Taken together, scyreprocin and SCY2 played a dual role in reproductive immunity and sperm AR. To our knowledge, this is the first report on the direct involvement of AMPs in sperm AR, which would expand the current understanding of the roles of AMPs in reproduction.


Assuntos
Anti-Infecciosos , Braquiúros , Acrossomo , Reação Acrossômica , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Peptídeos Antimicrobianos , Braquiúros/metabolismo , Masculino , Progesterona/metabolismo , Progesterona/farmacologia , Espermatozoides
12.
Int J Mol Sci ; 24(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36613722

RESUMO

New antimicrobial agents are urgently needed to address the increasing emergence and dissemination of multidrug-resistant bacteria. In the study, a chemically synthesized truncated peptide containing 22-amino acids derived from a C-type lectin homolog SpCTL6 of Scylla paramamosain was screened and found to exhibit broad-spectrum antimicrobial activity, indicating that it is an antimicrobial peptide (AMP), named Sp-LECin. Sp-LECin possessed the basic characteristics of most cationic AMPs, such as positive charge (+4) and a relatively high hydrophobicity (45%). After treatment with Sp-LECin, the disruption of microbial membrane integrity and even leakage of cellular contents was observed by scanning electron microscopy (SEM). In addition, Sp-LECin could bind lipopolysaccharide (LPS), increase the outer and inner membrane permeability and induce reactive oxygen species (ROS) production, ultimately leading to the death of Pseudomonas aeruginosa. Furthermore, Sp-LECin exhibited potent anti-biofilm activity against P. aeruginosa during both biofilm formation and maturation. Notably, Sp-LECin had no obvious cytotoxicity and could greatly improve the survival of P. aeruginosa-infected zebrafish, by approximately 40% over the control group after 72 h of treatment. This study indicated that Sp-LECin is a promising antibacterial agent with the potential to be used against devastating global pathogen infections such as P. aeruginosa.


Assuntos
Anti-Infecciosos , Infecções por Pseudomonas , Animais , Peixe-Zebra/metabolismo , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Antimicrobianos , Pseudomonas aeruginosa/metabolismo , Anti-Infecciosos/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Biofilmes
13.
Stat Med ; 40(8): 1947-1959, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33463746

RESUMO

Parallel-group thorough QT/QTc studies focus on the change of QT/QTc values at several time-matched points from a pretreatment day (baseline) to a posttreatment day for different groups of treatment. The International Council for Harmonisation E14 stresses that QTc prolongation beyond a threshold represents high cardiac risk and calls for a test on the largest time-matched treatment effect (QTc prolongation). QT/QTc analysis usually assumes a jointly multivariate normal (MVN) distribution of pretreatment and posttreatment QT/QTc values, with a blocked compound symmetry covariance matrix. Existing methods use an analysis of covariance (ANCOVA) model including day-averaged baseline as a covariate to deal with the MVN model. However, the ANCOVA model tends to underestimate the variation of the estimator for treatment effects, resulting in the inflation of empirical type I error rate when testing whether the largest QTc prolongation is beyond a threshold. In this article, we propose two new methods to estimate the time-matched treatment effects under the MVN model, including maximum likelihood estimation and ordinary-least-square-based two-stage estimation. These two methods take advantage of the covariance structure and are asymptotically efficient. Based on these estimators, powerful tests for QT/QTc prolongation are constructed. Simulation shows that the proposed estimators have smaller mean square error, and the tests can control the type I error rate with high power. The proposed methods are applied on testing the carryover effect of diltiazem to inhibit dofetilide in a randomized phase 1 trial.


Assuntos
Eletrocardiografia , Síndrome do QT Longo , Simulação por Computador , Frequência Cardíaca , Humanos
14.
Nucleic Acids Res ; 47(11): 5522-5529, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31114894

RESUMO

5-Methylcytosine (5mC) in DNA CpG islands is an important epigenetic biomarker for mammalian gene regulation. It is oxidized to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) by the ten-eleven translocation (TET) family enzymes, which are α-ketoglutarate (α-KG)/Fe(II)-dependent dioxygenases. In this work, we demonstrate that the epigenetic marker 5mC is modified to 5hmC, 5fC, and 5caC in vitro by another class of α-KG/Fe(II)-dependent proteins-the DNA repair enzymes in the AlkB family, which include ALKBH2, ALKBH3 in huamn and AlkB in Escherichia coli. Theoretical calculations indicate that these enzymes may bind 5mC in the syn-conformation, placing the methyl group comparable to 3-methylcytosine, the prototypic substrate of AlkB. This is the first demonstration of the AlkB proteins to oxidize a methyl group attached to carbon, instead of nitrogen, on a DNA base. These observations suggest a broader role in epigenetics for these DNA repair proteins.


Assuntos
5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Enzimas AlkB/metabolismo , Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/metabolismo , Homólogo AlkB 3 da Dioxigenase Dependente de alfa-Cetoglutarato/metabolismo , Citosina/análogos & derivados , Enzimas AlkB/genética , Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/genética , Homólogo AlkB 3 da Dioxigenase Dependente de alfa-Cetoglutarato/genética , Animais , Biologia Computacional , Ilhas de CpG , Citosina/metabolismo , DNA/genética , Metilação de DNA , Epigênese Genética , Humanos , Estrutura Molecular , Oxirredução
15.
Int J Mol Sci ; 23(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35008449

RESUMO

The abuse of antibiotics in aquaculture and livestock no doubt has exacerbated the increase in antibiotic-resistant bacteria, which imposes serious threats to animal and human health. The exploration of substitutes for antibiotics from marine animals has become a promising area of research, and antimicrobial peptides (AMPs) are worth investigating and considering as potential alternatives to antibiotics. In the study, we identified a novel AMP gene from the mud crab Scylla paramamosain and named it Sparanegtin. Sparanegtin transcripts were most abundant in the testis of male crabs and significantly expressed with the challenge of lipopolysaccharide (LPS) or Vibrio alginolyticus. The recombinant Sparanegtin (rSparanegtin) was expressed in Escherichia coli and purified. rSparanegtin exhibited activity against Gram-positive and Gram-negative bacteria and had potent binding affinity with several polysaccharides. In addition, rSparanegtin exerted damaging activity on the cell walls and surfaces of P. aeruginosa with rougher and fragmented appearance. Interestingly, although rSparanegtin did not show activity against V. alginolyticus in vitro, it played an immunoprotective role in S. paramamosain and exerted an immunomodulatory effect by modulating several immune-related genes against V. alginolyticus infection through significantly reducing the bacterial load in the gills and hepatopancreas and increasing the survival rate of crabs.


Assuntos
Peptídeos Antimicrobianos/genética , Peptídeos Antimicrobianos/farmacologia , Braquiúros/metabolismo , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Animais , Peptídeos Antimicrobianos/metabolismo , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Proteínas de Artrópodes/farmacologia , Braquiúros/genética , Braquiúros/microbiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lipopolissacarídeos/efeitos adversos , Masculino , Viabilidade Microbiana/efeitos dos fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Testículo/metabolismo , Distribuição Tecidual , Regulação para Cima , Vibrio alginolyticus/patogenicidade
16.
Molecules ; 26(17)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34500720

RESUMO

Mutation patterns of DNA adducts, such as mutational spectra and signatures, are useful tools for diagnostic and prognostic purposes. Mutational spectra of carcinogens derive from three sources: adduct formation, replication bypass, and repair. Here, we consider the repair aspect of 1,N6-ethenoadenine (εA) by the 2-oxoglutarate/Fe(II)-dependent AlkB family enzymes. Specifically, we investigated εA repair across 16 possible sequence contexts (5'/3' flanking base to εA varied as G/A/T/C). The results revealed that repair efficiency is altered according to sequence, enzyme, and strand context (ss- versus ds-DNA). The methods can be used to study other aspects of mutational spectra or other pathways of repair.


Assuntos
Adutos de DNA/química , Reparo do DNA/fisiologia , Adutos de DNA/genética , Reparo do DNA/genética , Mutação , Oxirredução
17.
Fish Shellfish Immunol ; 103: 442-453, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32446967

RESUMO

Apoptosis plays a key role in the immune defense against pathogen infection, and caspase is one of the most important protease enzyme families, which could initiate and execute apoptosis. Among crustaceans, several caspase genes have been reported. However, caspase in mud crab Scylla paramamosain, have not been identified yet. Here, in the present study, we characterized a new caspase, named as Sp-caspase, from S. paramamosain. The full-length cDNA sequence of Sp-caspase contained 966 bp open reading frame, encoding 322 amino acids, and its molecular weight was 36 kDa. This gene has three conserved domains of the caspase family, a prodomain, a large subunit P20 and a small subunit P10. Phylogenetic analysis showed that Sp-caspase was clustered into an effector caspase group. Sp-caspase mainly distributed in midgut, hepatopancreas, hemocytes and female ovaries, and the transcript was significantly regulated in different tissues after being challenged with Vibrio parahaemolyticus, Vibrio alginolyticus or LPS. After infection with V. alginolyticus, the apoptosis rate of hemocytes notably increased, while the mRNA level of Sp-caspase and hydrolysis activity of caspase 3/7 significantly decreased. Furthermore, in vitro assays showed that the recombinant protein tSp-caspase (deletion of Sp-caspase prodomain) could efficiently recognize and cleave human caspase 3/7 substrate Ac-DEVD-pNA, functioning as an effector caspase. Meanwhile, heterologous expression of Sp-caspase in several cell lines (HEK293T cells, HeLa cells and HighFive cells) could specifically induce cell apoptosis. Taken together, these data demonstrated that Sp-caspase could perform apoptosis as an effector caspase. In addition, it might be a negative regulator of hemocytes apoptosis under pathogen infection, which would contribute to homeostasis and immune defense of hemocytes in S. paramamosain.


Assuntos
Braquiúros/genética , Braquiúros/imunologia , Caspases/genética , Caspases/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Sequência de Bases , Caspases/química , Feminino , Perfilação da Expressão Gênica , Lipopolissacarídeos/farmacologia , Masculino , Filogenia , Alinhamento de Sequência , Vibrio alginolyticus/fisiologia , Vibrio parahaemolyticus/fisiologia
18.
Fish Shellfish Immunol ; 100: 152-160, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32147374

RESUMO

Bisphenol A (BPA), a well-known environmental endocrine-disrupting chemical (EDC), could pose a great toxicity risk to aquatic organisms. The present study aimed to evaluate the underlying role of long non-coding RNAs (lncRNAs) in BPA-induced immunotoxicity in head kidney (HK) macrophages of the red common carp (Cyprinus carpio), using lncRNA-RNA sequencing (RNA-Seq). In BPA-exposed HK macrophages group, 2,095 and 1,138 differentially expressed mRNAs (DEGs) and lncRNAs (DE-lncRNAs) were obtained, respectively, compared with controls. The qRT-PCR validation results of DEGs and DE-lncRNAs were similar to the RNA-Seq results. The KEGG analysis of DEGs and target genes of DE-lncRNAs have shown that some immune-related signaling pathways, including NF-kappa B, Toll-like receptor, B-cell receptor, Jak-STAT, and Hippo signaling pathways, were severely disrupted by BPA exposure. Moreover, we observed the synergic regulation of some mRNAs involved in immune response such as two hub genes traf6 and mapk1/3 and their upstream lncRNAs in HK macrophages upon the BPA exposure or its analogue bisphenol S (BPS) exposure. This suggested the dysregulation of lncRNAs by BPA or BPS may lead to a change in the expression of hub genes, which affects the cross-talk of various signaling pathways by interaction with other network genes. In conclusion, the present study demonstrates the potential role of lncRNAs in immunotoxicity of bisphenol compounds in red common carp HK macrophages, and our results provide evidence for further exploring lncRNA's role in EDC-induced toxicity in aquatic organisms.


Assuntos
Compostos Benzidrílicos/toxicidade , Imunotoxinas/toxicidade , Macrófagos/efeitos dos fármacos , Fenóis/toxicidade , RNA Longo não Codificante/genética , Animais , Carpas/imunologia , Células Cultivadas , Redes Reguladoras de Genes , Rim Cefálico/citologia , Rim Cefálico/efeitos dos fármacos , Rim Cefálico/imunologia , RNA Mensageiro , Análise de Sequência de RNA
19.
Neural Plast ; 2020: 1823454, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32714382

RESUMO

The utricle is one of the five sensory organs in the mammalian vestibular system, and while the utricle has a limited ability to repair itself, this is not sufficient for the recovery of vestibular function after hair cell (HC) loss induced by ototoxic drugs. In order to further explore the possible self-recovery mechanism of the adult mouse vestibular system, we established a reliable utricle epithelium injury model for studying the regeneration of HCs and examined the toxic effects of 3,3'-iminodiproprionitrile (IDPN) on the utricle in vivo in C57BL/6J mice, which is one of the most commonly used strains in inner ear research. This work focused on the epithelial cell loss, vestibular dysfunction, and spontaneous cell regeneration after IDPN administration. HC loss and supporting cell (SC) loss after IDPN treatment was dose-dependent and resulted in dysfunction of the vestibular system, as indicated by the swim test and the rotating vestibular ocular reflex (VOR) test. EdU-positive SCs were observed only in severely injured utricles wherein above 47% SCs were dead. No EdU-positive HCs were observed in either control or injured utricles. RT-qPCR showed transient upregulation of Hes5 and Hey1 and fluctuating upregulation of Axin2 and ß-catenin after IDPN administration. We conclude that a single intraperitoneal injection of IDPN is a practical way to establish an injured utricle model in adult C57BL/6J mice in vivo. We observed activation of Notch and Wnt signaling during the limited spontaneous HC regeneration after vestibular sensory epithelium damage, and such signaling might act as the promoting factors for tissue self-repair in the inner ear.


Assuntos
Células Ciliadas Vestibulares/efeitos dos fármacos , Nitrilas/toxicidade , Sáculo e Utrículo/efeitos dos fármacos , Animais , Camundongos , Camundongos Endogâmicos C57BL , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Testes de Função Vestibular , Via de Sinalização Wnt/efeitos dos fármacos
20.
Chem Res Toxicol ; 32(6): 1082-1086, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31088072

RESUMO

Hydrolyzable tannins are a class of polyphenolic compounds commonly found in natural products. In this work, we studied the in vitro inhibitory mechanism of six molecules in this class on ALKBH2, an Fe(II)/α-ketoglutarate-dependent DNA repair enzyme in the AlkB family. We determined the IC50 values of these compounds on the repair of 3-methylcytosine and 1-methyladenine, the prototypical substrates of ALKBH2. A structure-activity relationship was also observed between the strength of inhibition and the number of galloyl moieties in a molecule. In addition, we found that the inhibition by this class of polyphenolic compounds on ALKBH2 is through an iron-chelating mechanism.


Assuntos
Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Reparo do DNA , Inibidores Enzimáticos/farmacologia , Taninos Hidrolisáveis/farmacologia , Quelantes de Ferro/farmacologia , Homólogo AlkB 2 da Dioxigenase Dependente de alfa-Cetoglutarato/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , Taninos Hidrolisáveis/química , Quelantes de Ferro/química , Estrutura Molecular , Relação Estrutura-Atividade
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