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1.
Curr Issues Mol Biol ; 46(2): 1335-1347, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38392203

RESUMO

Bumblebees (B. terrestris) play a crucial role as highly efficient biological agents in commercial pollination. Understanding the molecular mechanisms governing their adaptation to diverse seasonal environments may pave the way for effective management strategies in the future. With the burgeoning advancement in post-genetic studies focusing on B. terrestris, there is a critical need to normalize quantitative real-time PCR (qRT-PCR) data using suitable reference genes. To address this necessity, we employed RefFinder, a software-based tool, to assess the suitability of several candidate endogenous control genes, including actin (ACT), arginine kinase (AK), elongation factor 1 alpha (EF1), glyceraldehyde-3-phosphate (GAPDH), phospholipase (PLA2), and ribosomal proteins (S18, S28). These genes were evaluated for their efficacy as biological endogenous controls by examining their expression patterns across various environmental conditions corresponding to different seasons (Spring, Summer, Autumn, Winter) and tissues (ovary, fat body, thorax, head) in bumblebees. Moreover, the study investigated the significance of selecting appropriate reference genes for three key genes involved in the juvenile hormone (JH) signaling pathways: Krüppel homolog 1 (Kr-h1), methyl farnesoate epoxidase (MFE), and Vitellogenin (Vg). Our research identifies specific genes suitable for normalization in B. terrestris, thereby offering valuable insights into gene expression and functional metabolic genetics under varying seasonal conditions. This catalog of reference genes will serve as a valuable resource for future research endeavors.

2.
Cancer ; 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39422602

RESUMO

BACKGROUND: In this single-arm, multicenter, phase 2 trial, the authors evaluated the efficacy and safety of avelumab plus gemcitabine in patients with leiomyosarcoma (LMS) who failed on first-line chemotherapy. METHODS: Patients with advanced LMS received avelumab 10 mg/kg on days 1 and 15 (for up to 24 months) plus gemcitabine 1000 mg/m2 on days 1, 8, and 15 of a 28-day cycle until they developed disease progression or intolerable toxicity. The primary end point was the objective response rate (ORR). RESULTS: In total, 38 patients were enrolled. Of these, 35 patients were evaluable, and the ORR was 20% (95% confidence interval; [CI], 8%-37%). The disease control rate was 71%, and the median duration of response was 21.8 months (range, 7.6 to ≥43.3 months). The median progression free-survival was 5.6 months (95% CI, 4.5-6.8 months), and the median overall survival was 27.5 months (95% CI, 20.4-34.6 months). Grade 3-4 adverse events occurred in 70% of patients, of which neutropenia was the most common (54%). Immune-mediated adverse events occurred in five patients (14%; hypothyroidism, n = 3; hepatitis, n = 2). Patients who had a higher density of tumor-infiltrating lymphocytes (greater than the median) exhibited better ORR (35% vs. 8%; p = .104), progression-free survival (median, 7.3 vs. 3.3 months; p = .024), and overall survival (median, not reached vs. 21.5 months; p = .027). CONCLUSIONS: The combination of avelumab and gemcitabine demonstrated promising efficacy and manageable safety in patients with advanced LMS who progressed on first-line therapy. Tumor-infiltrating lymphocyte density may be an important factor in predicting the response to combining immunotherapy with chemotherapy.

3.
Biochem Biophys Res Commun ; 723: 150166, 2024 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-38810321

RESUMO

CorA is a Mg2+ channel that plays a key role in the homeostasis of intracellular Mg2+ in bacteria and archaea. CorA consists of a cytoplasmic domain and a transmembrane domain and generates a Mg2+ pathway by forming a pentamer in the cell membrane. CorA gating is regulated via negative feedback by Mg2+, which is accommodated by the pentamerization interface of the CorA cytoplasmic domain (CorACD). The Mg2+-binding sites of CorACD differ depending on the species, suggesting that the Mg2+-binding modes and Mg2+-mediated gating mechanisms of CorA vary across prokaryotes. To define the Mg2+-binding mechanism of CorA in the Campylobacter jejuni pathogen, we structurally and biochemically characterized C. jejuni CorACD (cjCorACD). cjCorACD adopts a three-layered α/ß/α structure as observed in other CorA orthologs. Interestingly, cjCorACD exhibited enhanced thermostability in the presence of Ca2+, Ni2+, Zn2+, or Mn2+ in addition to Mg2+, indicating that cjCorACD interacts with diverse divalent cations. This cjCorACD stabilization is mediated by divalent cation accommodation by negatively charged residues located at the bottom of the cjCorACD structure away from the pentamerization interface. Consistently, cjCorACD exists as a monomer irrespective of the presence of divalent cations. We concluded that cjCorACD binds divalent cations in a unique pentamerization-independent manner.


Assuntos
Proteínas de Bactérias , Campylobacter jejuni , Cátions Bivalentes , Magnésio , Campylobacter jejuni/metabolismo , Campylobacter jejuni/química , Cátions Bivalentes/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Magnésio/metabolismo , Magnésio/química , Ligação Proteica , Sítios de Ligação , Modelos Moleculares , Domínios Proteicos , Cristalografia por Raios X , Estabilidade Proteica
4.
Small ; 20(23): e2308815, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38161254

RESUMO

Non-neural extracellular matrix (ECM) has limited application in humanized physiological neural modeling due to insufficient brain-specificity and safety concerns. Although brain-derived ECM contains enriched neural components, certain essential components are partially lost during the decellularization process, necessitating augmentation. Here, it is demonstrated that the laminin-augmented porcine brain-decellularized ECM (P-BdECM) is xenogeneic factor-depleted as well as favorable for the regulation of human neurons, astrocytes, and microglia. P-BdECM composition is comparable to human BdECM regarding brain-specificity through the matrisome and gene ontology-biological process analysis. As augmenting strategy, laminin 111 supplement promotes neural function by synergic effect with laminin 521 in P-BdECM. Annexin A1(ANXA1) and Peroxiredoxin(PRDX) in P-BdECM stabilized microglial and astrocytic behavior under normal while promoting active neuroinflammation in response to neuropathological factors. Further, supplementation of the brain-specific molecule to non-neural matrix also ameliorated glial cell inflammation as in P-BdECM. In conclusion, P-BdECM-augmentation strategy can be used to recapitulate humanized pathophysiological cerebral environments for neurological study.


Assuntos
Encéfalo , Diferenciação Celular , Matriz Extracelular , Laminina , Humanos , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Laminina/química , Encéfalo/metabolismo , Animais , Neurônios/metabolismo , Doenças Neuroinflamatórias/metabolismo , Suínos , Astrócitos/metabolismo , Microglia/metabolismo , Inflamação/patologia
5.
Small ; 20(22): e2308672, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38155506

RESUMO

Layered 2D transition metal dichalcogenides (TMDs) have been suggested as efficient substitutes for Pt-group metal electrocatalysts in the hydrogen evolution reaction (HER). However, poor catalytic activities in neutral and alkaline electrolytes considerably hinder their practical applications. Furthermore, the weak adhesion between TMDs and electrodes often impedes long-term durability and thus requires a binder. Here, a universal platform is reported for robust dual-atom doped 2D electrocatalysts with superior HER performance over a wide pH range media. V:Co-ReS2 on a wafer scale is directly grown on oxidized Ti foil by a liquid-phase precursor-assisted approach and subsequently used as highly efficient electrocatalysts. The catalytic performance surpasses that of Pt group metals in a high current regime (≥ 100 mA cm-2) at pH ≥ 7, with a high durability of more than 70 h in all media at 200 mA cm-2. First-principles calculations reveal that V:Co dual doping in ReS2 significantly reduces the water dissociation barrier and simultaneously enables the material to achieve the thermoneutral Gibbs free energy for hydrogen adsorption.

6.
BMC Infect Dis ; 24(1): 266, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418981

RESUMO

BACKGROUND: Serratia marcescens is a gram-negative bacterium that is widespread in the environment. S. marcescens bacteremia can be fatal during pregnancy and cause persistent chorioamnionitis. This study reports an outbreak of Serratia marcescens bloodstream infection (BSI) among high-risk pregnant women in an obstetric ward. The purpose of this study is to report our experience with the usefulness of the ATP test in hospital environmental management and to confirm that bloodstream infections of patients with the same strain were correlated by WGS testing. METHODS: This retrospective study collected the data of inpatients with S. marcescens bacteremia in obstetric ward for high-risk pregnant women from August 22, 2021, to October 14, 2021. We performed: an adenosine triphosphate (ATP) bioluminescence test in the environment with a high-contact area; environmental culture; on-site monitoring and staff education; and whole-genome sequencing (WGS) to evaluate genetic relationships among S. marcescens isolates. RESULTS: S. marcescens BSI occurred in four consecutive patients. None of the patients had central venous catheters. An ATP bioluminescence test revealed that high-contact areas and areas for injection preparation were not clean (≥ 1000 relative light units). However, S. marcescens was not identified in the environmental cultures, likely due to intensive environmental cleaning and discarding of potentially contaminated specimens before the culture test. On-site monitoring and education were conducted for 1 month. There were no further reports of BSI until 6 months after the last patient was discharged. WGS performed on three isolates from three patients indicated that the isolated S. marcescens was likely from the same strain. CONCLUSIONS: We controlled an S. marcescens outbreak by improving environmental cleaning as well as education of and behavior changes in healthcare workers. Using the ATP bioluminescence test can provide feedback on environmental cleaning and education. WGS played a role in determining the spread of BSI caused by the same strain.


Assuntos
Bacteriemia , Infecção Hospitalar , Sepse , Infecções por Serratia , Gravidez , Humanos , Feminino , Recém-Nascido , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Gestantes , Serratia marcescens/genética , Estudos Retrospectivos , Infecções por Serratia/epidemiologia , Infecções por Serratia/microbiologia , Sepse/epidemiologia , Surtos de Doenças , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Hospitais , Trifosfato de Adenosina , Unidades de Terapia Intensiva Neonatal
7.
BMC Public Health ; 24(1): 1534, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849810

RESUMO

BACKGROUND: Choosing a suitable job and leading a fulfilling professional life is vital for individuals, regardless of disability. Governments provide rehabilitation services to promote employment for individuals with disabilities, but research on their effects is limited. This study aimed to examine the impact of rehabilitation services on employment among people with physical disabilities in South Korea using propensity score matching. METHODS: This study utilized an observational research design. Data were obtained from the 2020 National Survey of Disabled Persons, including 1,757 individuals aged 20 or older with physical disabilities. Descriptive statistics, chi-square and independent t-tests, logistic regression, and propensity score matching were employed. RESULTS: The results for employment of individuals with physical disabilities showed no difference between the with rehabilitation services and the without rehabilitation services group. Based on subgroup analysis, when individuals with physical disabilities who rated their subjective health status low received rehabilitation services, it had a positive effect on employment. CONCLUSIONS: The results of this study could serve as foundational data for future policies and educational directions concerning rehabilitation services for persons with disabilities.


Assuntos
Pessoas com Deficiência , Emprego , Pontuação de Propensão , Humanos , Pessoas com Deficiência/reabilitação , Pessoas com Deficiência/estatística & dados numéricos , Feminino , Masculino , República da Coreia , Adulto , Emprego/estatística & dados numéricos , Pessoa de Meia-Idade , Adulto Jovem , Inquéritos e Questionários , Idoso
8.
Proc Natl Acad Sci U S A ; 118(50)2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34893540

RESUMO

Cellular homeostasis requires the sensing of and adaptation to intracellular oxygen (O2) and reactive oxygen species (ROS). The Arg/N-degron pathway targets proteins that bear destabilizing N-terminal residues for degradation by the proteasome or via autophagy. Under normoxic conditions, the N-terminal Cys (Nt-Cys) residues of specific substrates can be oxidized by dioxygenases such as plant cysteine oxidases and cysteamine (2-aminoethanethiol) dioxygenases and arginylated by ATE1 R-transferases to generate Arg-CysO2(H) (R-CO2). Proteins bearing the R-CO2 N-degron are targeted via Lys48 (K48)-linked ubiquitylation by UBR1/UBR2 N-recognins for proteasomal degradation. During acute hypoxia, such proteins are partially stabilized, owing to decreased Nt-Cys oxidation. Here, we show that if hypoxia is prolonged, the Nt-Cys of regulatory proteins can be chemically oxidized by ROS to generate Arg-CysO3(H) (R-CO3), a lysosomal N-degron. The resulting R-CO3 is bound by KCMF1, a N-recognin that induces K63-linked ubiquitylation, followed by K27-linked ubiquitylation by the noncanonical N-recognin UBR4. Autophagic targeting of Cys/N-degron substrates is mediated by the autophagic N-recognin p62/SQTSM-1/Sequestosome-1 through recognition of K27/K63-linked ubiquitin (Ub) chains. This Cys/N-degron-dependent reprogramming in the proteolytic flux is important for cellular homeostasis under both chronic hypoxia and oxidative stress. A small-compound ligand of p62 is cytoprotective under oxidative stress through its ability to accelerate proteolytic flux of K27/K63-ubiquitylated Cys/N-degron substrates. Our results suggest that the Nt-Cys of conditional Cys/N-degron substrates acts as an acceptor of O2 to maintain both O2 and ROS homeostasis and modulates half-lives of substrates through either the proteasome or lysosome by reprogramming of their Ub codes.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/fisiologia , Oxigênio/metabolismo , Animais , Autofagia , Linhagem Celular , Proteínas Ativadoras de GTPase/genética , Regulação da Expressão Gênica , Homeostase , Humanos , Interleucinas/genética , Interleucinas/metabolismo , Redes e Vias Metabólicas , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Oxirredução , Oxigênio/química
9.
Int J Mol Sci ; 25(17)2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39273565

RESUMO

Exosomes are nanovesicles 30-150 nm in diameter released extracellularly. Those isolated from human body fluids reflect the characteristics of their cells or tissues of origin. Exosomes carry extensive biological information from their parent cells and have significant potential as biomarkers for disease diagnosis and prognosis. However, there are limited studies utilizing exosomes in postmortem diagnostics. In this study, we extended our initial research which identified the presence and established detection methodologies for exosomes in postmortem fluids. We analyzed exosomal miRNA extracted from plasma and pericardial fluid samples of a control group (n = 13) and subjects with acute myocardial infarction (AMI; n = 24). We employed next-generation sequencing (NGS) to investigate whether this miRNA could serve as biomarkers for coronary atherosclerosis leading to acute myocardial infarction. Our analysis revealed 29 miRNAs that were differentially expressed in the AMI group compared to the control group. Among these, five miRNAs exhibited more than a twofold increase in expression across all samples from the AMI group. Specifically, miR-486-5p levels were significantly elevated in patients with high-grade (type VI or above) atherosclerotic plaques, as per the American Heart Association criteria, highlighting its potential as a predictive biomarker for coronary atherosclerosis progression. Our results indicate that postmortem-derived exosomal microRNAs can serve as potential biomarkers for various human diseases, including cardiovascular disorders. This finding has profound implications for forensic diagnostics, a field critically lacking diagnostic markers.


Assuntos
Biomarcadores , Exossomos , MicroRNAs , Humanos , Exossomos/metabolismo , Exossomos/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/genética , Autopsia , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/genética , Isquemia Miocárdica/metabolismo , Líquido Pericárdico/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala
10.
Int J Mol Sci ; 25(17)2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39273214

RESUMO

Neurofibromatosis type 1 (NF1), an autosomal dominant genetic disorder, is caused by mutations in the NF1 gene, which encodes the GTPase-activating protein neurofibromin. The pathogenesis of the tumor progression of benign plexiform neurofibromas (PNs) and malignant peripheral nerve sheath tumors (MPNSTs) remain unclear. Here, we found that interferon-induced transmembrane protein 1 (IFITM1) was downregulated in MPNST tissues compared to those in PN tissues from patients with NF1. Overexpression of IFITM1 in NF1-associated MPNST cells resulted in a significant decrease in Ras activation (GTP-Ras) and downstream extracellular regulatory kinase 1/2 (ERK1/2) phosphorylation, whereas downregulation of IFITM1 via treatment with small interfering RNA in normal Schwann cells had the opposite result, indicating that expression levels of IFITM1 are closely associated with tumor progression in NF1. Treatment of MPNST cells with interferon-gamma (IFN-γ) significantly augmented the expression of IFITM1, thereby leading to a decrease in Ras and ERK1/2 activation. Despite the small number of patient samples, these findings may potentially provide a new target for chemotherapy in patients with NF1-associated MPNSTs. In xenograft mice injected with MPNST cells, IFN-γ treatment successfully suppressed tumor progression with increased IFITM1 expression and decreased Ras and ERK1/2 activation in tumor tissues. Collectively, these results suggest that IFITM1 is closely involved in MPNST pathogenesis and that IFN-γ is a good candidate for the therapeutic treatment of MPNSTs in NF1.


Assuntos
Antígenos de Diferenciação , Neoplasias de Bainha Neural , Neurofibromatose 1 , Humanos , Animais , Neurofibromatose 1/metabolismo , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neurofibromatose 1/complicações , Camundongos , Neoplasias de Bainha Neural/metabolismo , Neoplasias de Bainha Neural/genética , Neoplasias de Bainha Neural/patologia , Linhagem Celular Tumoral , Antígenos de Diferenciação/metabolismo , Antígenos de Diferenciação/genética , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Masculino , Interferon gama/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas ras/metabolismo , Proteínas ras/genética , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Adulto
11.
BMC Nurs ; 23(1): 537, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113008

RESUMO

BACKGROUND: This study investigated the mediating effects of self-efficacy and social support on the relationship between stress and burnout among infection control nurses (ICNs) during an emerging infectious disease pandemic. METHODS: The study participants encompassed 210 ICNs with at least six months' experience in an infection control unit at a general hospital in South Korea during the COVID-19 pandemic. Data were analyzed using independent t-tests or one-way analysis of variance (ANOVA), while descriptive statistics were performed using SPSS/WIN 26.0 software. Hayes's PROCESS macro 4.2 software was used to verify the significance of the indirect effects of the mediators. RESULTS: Stress had a significant positive effect on burnout (ß = 0.80, p < .001), accounting for 73% of the variance. Self-efficacy (ß = - 0.26, p < .001) and social support (ß = - 0.11, p = .034) had a significant negative effect on burnout, accounting for 78% of the variance. Stress was lower when self-efficacy and social support were entered into the model (ß = 0.80 → 0.59), indicating that self-efficacy and social support mediated the relationship between stress and burnout. CONCLUSION: This study is significant in that it confirms the effects of self-efficacy and social support on the relationship between stress and burnout among ICNs. The results highlight the importance of establishing organizational support systems and developing and implementing programs for enhancing self-efficacy in order to reduce burnout among ICNs.

12.
Artigo em Inglês | MEDLINE | ID: mdl-39003647

RESUMO

BACKGROUND: Wheat allergy is one of the most prevalent allergens in Korea, decreasing quality of life and causing nutritional repercussions. OBJECTIVE: We aimed to investigate the efficacy and safety of the home-based wheat oral immunotherapy (OIT) using wheat noodles in children with a wheat allergy. METHODS: We conducted a retrospective study involving 72 children aged 3 to 17 years diagnosed with a wheat allergy. Patients received wheat OIT using wheat noodles (n = 50) and were compared with a historical control group (n = 22). Baseline characteristics, adverse events, and immunological changes were assessed. Predictors of successful desensitization were identified using logistic regression analysis. RESULTS: Among 50 patients completing the up-dosing phase, 82.0% achieved desensitization to 2,400 mg of wheat protein, compared to 4.5% in the control group (p < 0.001). During the up-dosing period, the median number of adverse reactions per person was 2, and anaphylaxis occurred in 30.0% (15/50). However, there were no life-threatening adverse events. In multivariable analysis, the presence of asthma (adjusted odds ratio [aOR], 8.88; 95% confidence interval [CI], 1.10-71.97; p = 0.041) and a higher ratio of specific IgE (sIgE) to ω-5-gliadin and total IgE (aOR 19.09, 95%CI 1.21-300.80, p = 0.036) were significantly associated with treatment outcomes of wheat OIT. CONCLUSION: Our study showed the safety and efficacy of home-based wheat OIT using boiled noodles in Korean children with wheat allergies. Careful consideration is warranted for patients with elevated baseline sIgE to ω-5-gliadin to total IgE ratio and a history of asthma.

13.
Cancer Cell Int ; 23(1): 108, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37268905

RESUMO

BACKGROUND: Although autophagy is an important mediator of metformin antitumor activity, the role of metformin in the crosstalk between autophagy and apoptosis remains unclear. The aim was to confirm the anticancer effect by inducing apoptosis by co-treatment with metformin and OSMI-1, an inhibitor of O-GlcNAcylation, in colon cancer cells. METHODS: Cell viability was measured by MTT in colon cancer cell lines HCT116 and SW620 cells. Co-treatment with metformin and OSMI-1 induced autophagy and apoptosis, which was analyzed using western blot, reverse transcription-polymerase chain reaction (RT-PCR) analysis, and fluorescence-activated cell sorting (FACS). Combined treatment with metformin and OSMI-1 synergistically inhibit the growth of HCT116 was confirmed by xenograft tumors. RESULTS: We showed that metformin inhibited mammalian target of rapamycin (mTOR) activity by inducing high levels of C/EBP homologous protein (CHOP) expression through endoplasmic reticulum (ER) stress and activating adenosine monophosphate-activated protein kinase (AMPK) to induce autophagy in HCT116 cells. Interestingly, metformin increased O-GlcNAcylation and glutamine:fructose-6-phosphate amidotransferase (GFAT) levels in HCT116 cells. Thus, metformin also blocks autophagy by enhancing O-GlcNAcylation, whereas OSMI-1 increases autophagy via ER stress. In contrast, combined metformin and OSMI-1 treatment resulted in continuous induction of autophagy and disruption of O-GlcNAcylation homeostasis, resulting in excessive autophagic flux, which synergistically induced apoptosis. Downregulation of Bcl2 promoted apoptosis via the activation of c-Jun N-terminal kinase (JNK) and CHOP overexpression, synergistically inducing apoptosis. The activation of IRE1α/JNK signaling by OSMI-1 and PERK/CHOP signaling by metformin combined to inhibit Bcl2 activity, ultimately leading to the upregulation of cytochrome c release and activation of caspase-3. CONCLUSIONS: In conclusion, combinatorial treatment of HCT116 cells with metformin and OSMI-1 resulted in more synergistic apoptosis being induced by enhancement of signal activation through ER stress-induced signaling rather than the cell protective autophagy function. These results in HCT116 cells were also confirmed in xenograft models, suggesting that this combination strategy could be utilized for colon cancer treatment.

14.
Int J Mol Sci ; 24(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37629127

RESUMO

The recombination mediator complex RecFOR, consisting of the RecF, RecO, and RecR proteins, is needed to initiate homologous recombination in bacteria by positioning the recombinase protein RecA on damaged DNA. Bacteria from the phylum Campylobacterota, such as the pathogen Campylobacter jejuni, lack the recF gene and trigger homologous recombination using only RecR and RecO. To elucidate the functional properties of C. jejuni RecR (cjRecR) in recombination initiation that differ from or are similar to those in RecF-expressing bacteria, we determined the crystal structure of cjRecR and performed structure-based binding analyses. cjRecR forms a rectangular ring-like tetrameric structure and coordinates a zinc ion using four cysteine residues, as observed for RecR proteins from RecF-expressing bacteria. However, the loop of RecR that has been shown to recognize RecO and RecF in RecF-expressing bacteria is substantially shorter in cjRecR as a canonical feature of Campylobacterota RecR proteins, indicating that cjRecR lost a part of the loop in evolution due to the lack of RecF and has a low RecO-binding affinity. Furthermore, cjRecR features a larger positive patch and exhibits substantially higher ssDNA-binding affinity than RecR from RecF-expressing bacteria. Our study provides a framework for a deeper understanding of the RecOR-mediated recombination pathway.


Assuntos
Campylobacter jejuni , Campylobacter jejuni/genética , Núcleo Celular , Cognição , Cisteína , Dano ao DNA
15.
Biochem Biophys Res Commun ; 586: 49-54, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34826700

RESUMO

Maltodextrin glucosidase (MalZ) is a key enzyme in the maltose utilization pathway in Escherichia coli that liberates glucose from the reducing end of the short malto-oligosaccharides. Unlike other enzymes in the GH13_21 subfamily, the hydrolytic activity of MalZ is limited to maltodextrin rather than long starch substrates, forming various transglycosylation products in α-1,3, α-1,4 or α-1,6 linkages. The mechanism for the substrate binding and hydrolysis of this enzyme is not well understood yet. Here, we present the dimeric crystal structure of MalZ, with the N-domain generating a unique substrate binding groove. The N-domain bears CBM34 architecture and forms a part of the active site in the catalytic domain of the adjacent molecule. The groove found between the N-domain and catalytic domain from the adjacent molecule, shapes active sites suitable for short malto-oligosaccharides, but hinders long stretches of oligosaccharides. The conserved residue of E44 protrudes at subsite +2, elucidating the hydrolysis pattern of the substrate by the glucose unit from the reducing end. The structural analysis provides a molecular basis for the substrate specificity and the enzymatic property, and has potential industrial application for protein engineering.


Assuntos
Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Glucose/química , Glicosídeo Hidrolases/química , Polissacarídeos/química , Biocatálise , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Glucose/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hidrólise , Modelos Moleculares , Polissacarídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
16.
Small ; 18(15): e2200060, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35229462

RESUMO

Macrophages (Mφs) are characterized by remarkable plasticity, an essential component of chronic inflammation. Thus, an appropriate and timely transition from proinflammatory (M1) to anti-inflammatory (M2) Mφs during wound healing is vital to promoting resolution of acute inflammation and enhancing tissue repair. Herein, exosomes derived from M2-Mφs (M2-Exos), which contain putative key regulators driving Mφ polarization, are used as local microenvironmental cues to induce reprogramming of M1-Mφs toward M2-Mφs for effective wound management. As an injectable controlled release depot for exosomes, hydrolytically degradable poly(ethylene glycol) (PEG) hydrogels (Exogels) are designed and employed for encapsulating M2-Exos to maximize their therapeutic effects in cutaneous wound healing. The degradation time of the hydrogels is adjustable from 6 days or up to 27 days by controlling the crosslinking density and tightness. The localization of M2-Exos leads to a successful local transition from M1-Mφs to M2-Mφs within the lesion for more than 6 days, followed by enhanced therapeutic effects including rapid wound closure and increased healing quality in an animal model for cutaneous wound healing. Collectively, the hydrolytically degradable PEG hydrogel-based exosome delivery system may serve as a potential tool in regulating local polarization state of Mφs, which is crucial for tissue homeostasis and wound repair.


Assuntos
Exossomos , MicroRNAs , Animais , Materiais Biocompatíveis/metabolismo , Preparações de Ação Retardada , Exossomos/metabolismo , Hidrogéis , Inflamação/metabolismo , Macrófagos/metabolismo , MicroRNAs/metabolismo , Cicatrização/fisiologia
17.
Biomacromolecules ; 23(11): 4547-4561, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36130109

RESUMO

A type of ultrathin films has been developed for suppressing capsule formation induced by medical silicone implants and hence reducing the inflammation response to such formation and the differentiation to myofibroblasts. The films were each fabricated from hyaluronic acid (HA) and modified ß-cyclodextrin (Mod-ß-CyD) polymer which was synthesized with a cyclodextrin with partially substituted quaternary amine. Ultrathin films comprising HA and Mod-ß-CyD or poly(allylamine hydrochloride) (PAH) were fabricated by using a layer-by-layer dipping method. The electrostatic interactions produced from the functional groups of Mod-ß-CyD and HA influenced the surface morphology, wettability, and bio-functional activity of the film. Notably, medical silicone implants coated with PAH/HA and Mod-ß-CyD multilayers under a low pH condition exhibited excellent biocompatibility and antibiofilm and anti-inflammation properties. Implantation of these nanoscale film-coated silicones showed a reduced capsular thickness as well as reduced TGFß-SMAD signaling, myofibroblast differentiation, biofilm formation, and inflammatory response levels. We expect our novel coating system to be considered a strong candidate for use in various medical implant applications in order to decrease implant-induced capsule formation.


Assuntos
Infecções Bacterianas , beta-Ciclodextrinas , Humanos , Ácido Hialurônico/química , Polímeros , Silicones/química
18.
BMC Public Health ; 22(1): 2085, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36380350

RESUMO

BACKGROUND: The inclusion of transgender soldiers in the military service raises a fundamental question about the dichotomous categorization of human sexes based on anatomy and gender role within a specialized organization where the most masculine is commonly accepted. In March 2021, Hee-Soo Byun, the first transgender soldier in Korea to come out in public, and who was forcefully discharged after gender affirming surgery, died by suicide. With no anti-discrimination laws, the cultural background of the Korean society hardly creates an LGBT (Lesbian, Gay, Bisexual, and Transgender) - friendly environment and shows a negative attitude towards gender minorities. METHODS: A total of 193 online news article headlines were analyzed, and 1046 comments were categorized inductively based on the presented rationales. RESULTS: Before Byun's public appearance, the frequent use of provocative expressions, which could evoke prejudice and discrimination, was found in published article headlines. Of the 724 comments that presented opinions on transgender soldiers, approximately 75% opposed Byun serving in the military in any form, including as a female soldier. CONCLUSIONS: This study aimed to investigate online news articles and the comments regarding Byun's case to estimate the acceptability of transgender people serving in the military. The results of this study are expected to serve as a basis for the formulation of policies that protect the human rights of transgender people.


Assuntos
Militares , Minorias Sexuais e de Gênero , Pessoas Transgênero , Transexualidade , Feminino , Humanos , República da Coreia
19.
Int J Mol Sci ; 23(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36077065

RESUMO

Homologous recombination is involved in repairing DNA damage, contributing to maintaining the integrity and stability of viral and cellular genomes. In bacteria, the recombination mediator proteins RecO and RecR are required to load the RecA recombinase on ssDNA for homologous recombination. To structurally and functionally characterize RecO, we determined the crystal structure of RecO from Campylobacter jejuni (cjRecO) at a 1.8 Å resolution and biochemically assessed its capacity to interact with DNA and a metal ion. cjRecO folds into a curved rod-like structure that consists of an N-terminal domain (NTD), C-terminal domain (CTD), and Zn2+-binding domain (ZnD). The ZnD at the end of the rod-like structure coordinates three cysteine residues and one histidine residue to accommodate a Zn2+ ion. Based on an extensive comparative analysis of RecO structures and sequences, we propose that the Zn2+-binding consensus sequence of RecO is CxxC…C/HxxC/H/D. The interaction with Zn2+ is indispensable for the protein stability of cjRecO but does not seem to be required for the recombination mediator function. cjRecO also interacts with ssDNA as part of its biological function, potentially using the positively charged patch in the NTD and CTD. However, cjRecO displays a low ssDNA-binding affinity, suggesting that cjRecO requires RecR to efficiently recognize ssDNA for homologous recombination.


Assuntos
Campylobacter jejuni , Proteínas de Bactérias/metabolismo , Campylobacter jejuni/genética , Campylobacter jejuni/metabolismo , DNA/química , DNA de Cadeia Simples , Proteínas de Ligação a DNA/metabolismo , Zinco
20.
Int J Mol Sci ; 23(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36499254

RESUMO

Tg2576 transgenic mice for Alzheimer's disease (AD) exhibited significant phenotypes for neuropathological constipation, but no research has been conducted on the association of the fecal microbiota with dysbiosis. The correlation between fecal microbiota composition and neuropathological constipation in Tg2576 mice was investigated by examining the profile of fecal microbiota and fecal microbiota transplantation (FMT) in 9-10-month-old Tg2576 mice with the AD phenotypes and constipation. Several constipation phenotypes, including stool parameters, colon length, and histopathological structures, were observed prominently in Tg2576 mice compared to the wild-type (WT) mice. The fecal microbiota of Tg2576 mice showed decreases in Bacteroidetes and increases in the Firmicutes and Proteobacteria populations at the phylum level. The FMT study showed that stool parameters, including weight, water content, and morphology, decreased remarkably in the FMT group transplanted with a fecal suspension of Tg2576 mice (TgFMT) compared to the FMT group transplanted with a fecal suspension of WT mice (WFMT). The distribution of myenteric neurons and the interstitial cells of Cajal (ICC), as well as the enteric nervous system (ENS) function, remained lower in the TgFMT group. These results suggest that the neuropathological constipation phenotypes of Tg2576 mice may be tightly linked to the dysbiosis of the fecal microbiota.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Disbiose/microbiologia , Transplante de Microbiota Fecal/métodos , Fezes/microbiologia , Constipação Intestinal/terapia , Camundongos Transgênicos
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