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1.
Chem Rev ; 123(16): 10381-10431, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37524057

RESUMO

The ability to site-selectively modify equivalent functional groups in a molecule has the potential to streamline syntheses and increase product yields by lowering step counts. Enzymes catalyze site-selective transformations throughout primary and secondary metabolism, but leveraging this capability for non-native substrates and reactions requires a detailed understanding of the potential and limitations of enzyme catalysis and how these bounds can be extended by protein engineering. In this review, we discuss representative examples of site-selective enzyme catalysis involving functional group manipulation and C-H bond functionalization. We include illustrative examples of native catalysis, but our focus is on cases involving non-native substrates and reactions often using engineered enzymes. We then discuss the use of these enzymes for chemoenzymatic transformations and target-oriented synthesis and conclude with a survey of tools and techniques that could expand the scope of non-native site-selective enzyme catalysis.


Assuntos
Engenharia de Proteínas , Catálise
2.
Am J Respir Crit Care Med ; 209(4): 362-373, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38113442

RESUMO

Despite progress in elucidation of disease mechanisms, identification of risk factors, biomarker discovery, and the approval of two medications to slow lung function decline in idiopathic pulmonary fibrosis and one medication to slow lung function decline in progressive pulmonary fibrosis, pulmonary fibrosis remains a disease with a high morbidity and mortality. In recognition of the need to catalyze ongoing advances and collaboration in the field of pulmonary fibrosis, the NHLBI, the Three Lakes Foundation, and the Pulmonary Fibrosis Foundation hosted the Pulmonary Fibrosis Stakeholder Summit on November 8-9, 2022. This workshop was held virtually and was organized into three topic areas: 1) novel models and research tools to better study pulmonary fibrosis and uncover new therapies, 2) early disease risk factors and methods to improve diagnosis, and 3) innovative approaches toward clinical trial design for pulmonary fibrosis. In this workshop report, we summarize the content of the presentations and discussions, enumerating research opportunities for advancing our understanding of the pathogenesis, treatment, and outcomes of pulmonary fibrosis.


Assuntos
Pesquisa Biomédica , Fibrose Pulmonar Idiopática , Estados Unidos , Humanos , National Heart, Lung, and Blood Institute (U.S.) , Lagos , Fibrose Pulmonar Idiopática/diagnóstico , Fibrose Pulmonar Idiopática/terapia , Fatores de Risco
3.
Am J Respir Crit Care Med ; 209(11): 1304-1313, 2024 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-38477657

RESUMO

Acute respiratory distress syndrome (ARDS) is associated with long-term impairments in brain and muscle function that significantly impact the quality of life of those who survive the acute illness. The mechanisms underlying these impairments are not yet well understood, and evidence-based interventions to minimize the burden on patients remain unproved. The NHLBI of the NIH assembled a workshop in April 2023 to review the state of the science regarding ARDS-associated brain and muscle dysfunction, to identify gaps in current knowledge, and to determine priorities for future investigation. The workshop included presentations by scientific leaders across the translational science spectrum and was open to the public as well as the scientific community. This report describes the themes discussed at the workshop as well as recommendations to advance the field toward the goal of improving the health and well-being of ARDS survivors.


Assuntos
Síndrome do Desconforto Respiratório , Sobreviventes , Humanos , Síndrome do Desconforto Respiratório/terapia , Síndrome do Desconforto Respiratório/fisiopatologia , Estados Unidos , National Heart, Lung, and Blood Institute (U.S.) , Qualidade de Vida , Encéfalo/fisiopatologia
4.
South Med J ; 116(11): 863-870, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37913804

RESUMO

OBJECTIVES: Determine the association of high neutrophil-to-lymphocyte ratio (NLR) values with inpatient mortality and other outcomes in older veterans hospitalized with coronavirus disease 2019 (COVID-19). METHODS: This was a retrospective, multicenter, cohort study of hospitalized adults, with laboratory-confirmed COVID-19 infection who were studied for 1 year after discharge or until death. The NLR was categorized into tertiles, and we determined frailty status with the 31-item Veterans Affairs Frailty Index. Multivariate logistic regression and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were performed to assess the association between NLR and clinical outcomes. RESULTS: The study included 615 hospitalized adult veterans, mean age 66.12 (standard deviation 14.79) years, 93.82% (n = 577) male, 57.56% (n = 354) White, 81.0% (n = 498) non-Hispanic, median body mass index of 30.70 (interquartile range 25.64-34.99, standard deviation 7.13), and median length of stay of 8 days (interquartile range 3-15). Individuals in the middle and upper tertile groups had higher inpatient mortality (8.37%, n = 17 and 18.36%, n = 38, respectively) as compared with the lower tertile (2.93%, n = 6, P < 0.001). Compared with the lowest tertile, the middle and upper tertiles had a higher risk of inpatient mortality (aOR 3.75, 95% CI 1.38-10.21, P = 0.01, and aOR 8.13, 95% CI 3.18-20.84, P < 0.001, respectively). The highest tertile had a higher odds of intensive care unit admission (aOR 4.47, 95% CI 2.33-8.58, P < 0.001) and intensive care unit transfer (aOR 3.54, 95% CI 1.84-6.81, P < 0.001). CONCLUSIONS: The NLR score is a clinically useful tool to predict in-hospital mortality in older patients with COVID-19.


Assuntos
COVID-19 , Fragilidade , Veteranos , Adulto , Humanos , Masculino , Idoso , Adolescente , Estudos de Coortes , Estudos Retrospectivos , Neutrófilos , Pacientes Internados , Linfócitos
5.
Angew Chem Int Ed Engl ; 62(15): e202301370, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36757808

RESUMO

FeII - and α-ketoglutarate-dependent halogenases and oxygenases can catalyze site-selective functionalization of C-H bonds via a variety of C-X bond forming reactions, but achieving high chemoselectivity for functionalization using non-native functional groups remains rare. The current study shows that directed evolution can be used to engineer variants of the dioxygenase SadX that address this challenge. Site-selective azidation of succinylated amino acids and a succinylated amine was achieved as a result of mutations throughout the SadX structure. The installed azide group was reduced to a primary amine, and the succinyl group required for azidation was enzymatically cleaved to provide the corresponding amine. These results provide a promising starting point for evolving additional SadX variants with activity on structurally distinct substrates and for enabling enzymatic C-H functionalization with other non-native functional groups.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato , Ferro , Ferro/química , Oxigenases , Compostos Ferrosos/química , Aminas
6.
Inorg Chem ; 61(36): 14477-14485, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36044713

RESUMO

Mononuclear non-heme Fe(II)- and α-ketoglutarate-dependent oxygenases (FeDOs) catalyze a site-selective C-H hydroxylation. Variants of these enzymes in which a conserved Asp/Glu residue in the Fe(II)-binding facial triad is replaced by Ala/Gly can, in some cases, bind various anionic ligands and catalyze non-native chlorination and bromination reactions. In this study, we explore the binding of different anions to an FeDO facial triad variant, SadX, and the effects of that binding on HO• vs X• rebound. We establish not only that chloride and bromide enable non-native halogenation reactions but also that all anions investigated, including azide, cyanate, formate, and fluoride, significantly accelerate and influence the site selectivity of SadX hydroxylation catalysis. Azide and cyanate also lead to the formation of products resulting from N3•, NCO•, and OCN• rebound. While fluoride rebound is not observed, the rate acceleration provided by this ligand leads us to calculate barriers for HO• and F• rebound from a putative Fe(III)(OH)(F) intermediate. These calculations suggest that the lack of fluorination is due to the relative barriers of the HO• and F• rebound transition states rather than an inaccessible barrier for F• rebound. Together, these results improve our understanding of the FeDO facial triad variant tolerance of different anionic ligands, their ability to promote rebound involving these ligands, and inherent rebound preferences relative to HO• that will aid efforts to develop non-native catalysis using these enzymes.


Assuntos
Ácidos Cetoglutáricos , Oxigenases , Azidas , Cianatos , Compostos Férricos , Compostos Ferrosos/química , Fluoretos , Ácidos Cetoglutáricos/química , Ligantes , Oxigenases/metabolismo
7.
Lipids Health Dis ; 21(1): 22, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35172832

RESUMO

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide characterized by disparities in age, gender, race and anatomic sites. The mechanism underlying pathogenesis, progression and disparities of CRC remains unclear. This study aims to reveal the association of expression levels of enzymes related to cholesteryl ester (CE) metabolism with pathogenesis, progression and disparities of CRC. METHODS: The differences in gene expression levels were analyzed for enzymes in CE synthesis (acyl CoA: cholesterol acyltransferase 1 and 2, ACAT1, and ACAT2), and in CE hydrolysis (neutral cholesterol ester hydrolase, NCEH1 and lysosomal acid lipase, LAL) on TNMplot platform between CRC and normal colorectal tissues (NCT) in a large cohort. The differences in protein expression levels for these enzymes were determined by Immunochemistry (IHC) performed on tissue microarray containing 96 pairs of CRC and benign colorectal tissues (BCT) from different patient populations. The expression level represented as IHC score of each enzyme was compared between CRC and BCT in entire population and populations stratified by race, gender and anatomic sites. Student's t-test, Fisher exact test and ANOVA were used for data analysis. Significant p value was set at P<0.05. RESULTS: The gene expression level of ACAT1 was significantly lower in CRC than in NCT (P = 2.15e-119). The gene expression level of ACAT2 was not statistically different between CRC and NCT. The gene expression level of LIPA (encoding LAL) was significantly higher in CRC than in NCT (P = 2.01e-14). No data was found for the gene expression level of NCEH1. The IHC score of ACAT1was significantly lower in CRC than in BCT in all studied populations and in sub site of colon, but not in that of rectum. The IHC score of ACAT2 was not statistically different between CRC and BCT. IHC score of NCEH1 was significantly higher in CRC than in BCT only in African American (AA) population. The IHC score of LAL was significantly higher in CRC than in BCT in all studied populations and in all sub sites. In addition, decreased ACAT1 in CRC significantly correlated to progression of CRC: the lower IHC score of ACAT1, the more advanced clinical stage of CRC will be. CONCLUSIONS: This study revealed that altered expression levels in enzymes related to CE metabolism highly correlate to the pathogenesis, clinical progression and disparities of CRC. The results will add revenue in elucidating mechanisms underlying progression of CRC, and shed light on seeking biomarkers and exploring therapeutic targets for CRC in a new direction.


Assuntos
Ésteres do Colesterol , Neoplasias Colorretais , Ésteres do Colesterol/metabolismo , Neoplasias Colorretais/genética , Humanos , Esterol Esterase/genética , Esterol Esterase/metabolismo , Esterol O-Aciltransferase/genética , Esterol O-Aciltransferase/metabolismo
8.
Aging Clin Exp Res ; 34(8): 1837-1843, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35522368

RESUMO

BACKGROUND: Frailty, a clinical syndrome characterized by vulnerability to stressors resulting from multisystemic loss of physiological reserve. The use of benzodiazepines in older adults has been associated with confusion, sedation, and cognitive impairment, which in turn may lead to frailty. AIMS: The purpose of this study was to determine the cross-sectional association between frailty and chronic past or current use of benzodiazepine drugs among older US Veterans. METHODS/DESIGN: This is a cross-sectional study of community-dwelling older Veterans who had determinations of frailty. Benzodiazepine prescription data were obtained via EHR. A 31-item VA Frailty Index (VA-FI) was generated at the time of the assessment. We categorized Veterans into robust (FI ≤ 0.10), pre-frail (FI 0.10-0.21), and Frail (FI ≥ 0.21). After adjusting for sociodemographic characteristics, we calculated ORs and 95% CIs using a binomial logistic regression (BLR) model to assess the cross-sectional association between benzodiazepine use and frailty. RESULTS: Population sample consisted of 17,423 Veterans, mean age 75.53 (SD = 8.03) years, 70.80% Caucasian, 97.34% male, 14,545 (83.50%) patients were non-users of benzodiazepine drugs, 2408 (13.80%) had a past use, and 470 (2.70%) were current users. In BLR, individuals with past (OR 2.51, 95% CI 2.30-2.74, p < .001) or current (OR 2.36, 95% CI 1.96-2.83, p < .001) use showed a higher association with frailty as compared to individuals who were non-users. CONCLUSIONS: The use of benzodiazepine was cross-sectionally associated with frailty in older Veterans. These results suggest that screening for frailty in patients with past or current exposure to benzodiazepine medications may be necessary for proper management.


Assuntos
Fragilidade , Idoso , Benzodiazepinas/efeitos adversos , Estudos Transversais , Feminino , Idoso Fragilizado/psicologia , Fragilidade/epidemiologia , Fragilidade/psicologia , Avaliação Geriátrica/métodos , Humanos , Vida Independente/psicologia , Masculino
9.
Exp Parasitol ; 222: 108077, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33465379

RESUMO

Protein arginine methylation regulates several cellular events, including epigenetics, splicing, translation, and stress response, among others. This posttranslational modification is catalyzed by protein arginine methyltransferases (PRMTs), which according to their products are classified from type I to type IV. The type I produces monomethyl arginine and asymmetric dimethyl arginine; in mammalian there are six families of this PRMT type (PRMT1, 2, 3, 4, 6, and 8). The protozoa parasite Entamoeba histolytica has four PRMTs related to type I; three of them are similar to PRMT1, but the other one does not show significant homology to be grouped in any known PRMT family, thus we called it as atypical PRMT (EhPRMTA). Here, we showed that EhPRMTA does not contain several of the canonical amino acid residues of type I PRMTs, confirming that it is an atypical PRMT. A specific antibody against EhPRMTA localized this protein in cytoplasm. The recombinant EhPRMTA displayed catalytic activity on commercial histones and the native enzyme modified its expression level during heat shock and erythrophagocytosis. Besides, the knockdown of EhPRMTA produced an increment in cell growth, and phagocytosis, but decreases cell migration and the survival of trophozoites submitted to heat shock, suggesting that this protein is involved in regulate negatively or positively these events, respectively. Thus, results suggest that this methyltransferase regulates some cellular functions related to virulence and cell surviving.


Assuntos
Entamoeba histolytica/enzimologia , Entamoeba histolytica/patogenicidade , Proteína-Arginina N-Metiltransferases/metabolismo , Sequência de Aminoácidos , Movimento Celular , Proliferação de Células/fisiologia , Sequência Conservada , Entamoeba histolytica/citologia , Entamoeba histolytica/metabolismo , Eritrócitos/metabolismo , Regulação Enzimológica da Expressão Gênica , Técnicas de Silenciamento de Genes , Resposta ao Choque Térmico/fisiologia , Fagocitose , Processamento de Proteína Pós-Traducional/fisiologia , Proteína-Arginina N-Metiltransferases/classificação , Proteína-Arginina N-Metiltransferases/genética , Virulência
10.
Molecules ; 26(4)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33672163

RESUMO

To date very few promising leads from natural products (NP) secondary metabolites with antiviral and immunomodulatory properties have been identified for promising/potential intervention for COVID-19. Using in-silico docking studies and genome based various molecular targets, and their in vitro anti-SARS CoV-2 activities against whole cell and/or selected protein targets, we select a few compounds of interest, which can be used as potential leads to counteract effects of uncontrolled innate immune responses, in particular those related to the cytokine storm. A critical factor for prevention and treatment of SARS-CoV-2 infection relates to factors independent of viral infection or host response. They include population-related variables such as concurrent comorbidities and genetic factors critically relevant to COVID-19 health disparities. We discuss population risk factors related to SARS-CoV-2. In addition, we focus on virulence related to glucose-6-phosphate dehydrogenase deficiency (G6PDd), the most common human enzymopathy. Review of data on the response of individuals and communities with high prevalence of G6PDd to NP, prompts us to propose the rationale for a population-specific management approach to rationalize design of therapeutic interventions of SARS-CoV-2 infection, based on use of NP. This strategy may lead to personalized approaches and improve disease-related outcomes.


Assuntos
Produtos Biológicos , Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Antivirais/química , Antivirais/uso terapêutico , Produtos Biológicos/química , Produtos Biológicos/uso terapêutico , COVID-19/epidemiologia , Deficiência de Glucosefosfato Desidrogenase/tratamento farmacológico , Deficiência de Glucosefosfato Desidrogenase/epidemiologia , Humanos
11.
J Synchrotron Radiat ; 27(Pt 5): 1278-1288, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32876603

RESUMO

An accurate knowledge of the parameters governing the kinetics of block copolymer self-assembly is crucial to model the time- and temperature-dependent evolution of pattern formation during annealing as well as to predict the most efficient conditions for the formation of defect-free patterns. Here, the self-assembly kinetics of a lamellar PS-b-PMMA block copolymer under both isothermal and non-isothermal annealing conditions are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS) experiments with a novel modelling methodology that accounts for the annealing history of the block copolymer film before it reaches the isothermal regime. Such a model allows conventional studies in isothermal annealing conditions to be extended to the more realistic case of non-isothermal annealing and prediction of the accuracy in the determination of the relevant parameters, namely the correlation length and the growth exponent, which define the kinetics of the self-assembly.

12.
Exp Physiol ; 105(12): 2154-2167, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33150708

RESUMO

NEW FINDINGS: What is the central question of this study? What is the localization and distribution pattern of adenomatous polyposis coli (APC) in intestinal epithelial cells? Does this distribution change in different regions of the colon or in the condition of inflammation? What is the main finding and its importance? Colonic epithelia from mice and humans contain a subset of goblet cells displaying high APC levels. The number of APChigh goblet cells increases in inflamed tissue, which also displays increased GRP78, indicating potential stress from mucin production. In cultured human colon cells, expression of interleukin 1 pathway components (inducers of MUC2 expression) is reduced upon APC depletion raising the potential for APC participation in an inflammatory response. ABSTRACT: Adenomatous polyposis coli (APC) serves as a gatekeeper of intestinal homeostasis by promoting cellular differentiation and maintaining crypt architecture. Although appreciated as a critical colon tumour suppressor, roles for APC in disease states such as inflammation have yet to be fully delineated. This study aimed to characterize the localization of APC protein in gastrointestinal tissues from human patients with active inflammatory bowel disease and mice with dextran sodium sulfate (DSS)-induced colitis. Fluorescence immunohistochemistry revealed a subset of goblet cells with elevated Apc staining intensity in the small intestines and proximal/medial colons of mice. Upon induction of colitis with DSS, these 'APChigh ' goblet cells remained in the proximal and medial colon, but now were also observed in the distal colon. This phenotype was recapitulated in humans, with APChigh goblet cells observed only in the descending colons of patients with active ulcerative colitis. In cultured human colon cells derived from normal tissue, APC depletion reduced expression of mRNAs encoding the interleukin 1 (IL1) signalling pathway components IL1ß and interleukin-1 receptor (IL1R), known regulators of Muc2 expression. Treating cancer cells lacking wild-type APC with IL1ß, or induction of full-length APC in these cells led to increases in IL1R and MUC2 expression. Combining IL1ß treatment with APC induction led to an increase of MUC2 expression greater than expected for additive affects, suggesting that APC sensitizes cells to IL1 signalling. These findings suggest that APC has novel roles in maintaining proper goblet cell function, thus providing further evidence for APC as an important factor in intestinal tissue homeostasis and disease.


Assuntos
Polipose Adenomatosa do Colo/patologia , Colo/patologia , Células Caliciformes/patologia , Inflamação/patologia , Polipose Adenomatosa do Colo/metabolismo , Animais , Células Cultivadas , Colo/metabolismo , Chaperona BiP do Retículo Endoplasmático , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Células Caliciformes/metabolismo , Humanos , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mucina-2/metabolismo , Receptores Tipo I de Interleucina-1/metabolismo , Transdução de Sinais/fisiologia
13.
Vet Res ; 51(1): 36, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32138772

RESUMO

Mannheimia haemolytica serotype A2 is the principal cause of pneumonic mannheimiosis in ovine and caprine livestock; this disease is a consequence of immune suppression caused by stress and associated viruses and is responsible for significant economic losses in farm production worldwide. Gram-negative bacteria such as M. haemolytica produce outer membrane (OM)-derived spherical structures named outer membrane vesicles (OMVs) that contain leukotoxin and other biologically active virulence factors. In the present study, the relationship between M. haemolytica A2 and bovine lactoferrin (BLf) was studied. BLf is an 80 kDa glycoprotein that possesses bacteriostatic and bactericidal properties and is part of the mammalian innate immune system. Apo-BLf (iron-free) showed a bactericidal effect against M. haemolytica A2, with an observed minimal inhibitory concentration (MIC) of 16 µM. Sublethal doses (2-8 µM) of apo-BLf increased the release of OMVs, which were quantified by flow cytometry. Apo-BLf modified the normal structure of the OM and OMVs, as observed through transmission electron microscopy. Apo-BLf also induced lipopolysaccharide (LPS) release from bacteria, disrupting OM permeability and functionality, as measured by silver staining and SDS and polymyxin B cell permeability assays. Western blot results showed that apo-BLf increased the secretion of leukotoxin in M. haemolytica A2 culture supernatants, possibly through its iron-chelating activity. In contrast, holo-BLf (with iron) did not have this effect, possibly due to differences in the tertiary structure between these proteins. In summary, apo-BLf affected the levels of several M. haemolytica virulence factors and could be evaluated for use in animals as an adjuvant in the treatment of ovine mannheimiosis.


Assuntos
Antibacterianos/farmacologia , Exotoxinas , Lactoferrina/farmacologia , Mannheimia haemolytica/efeitos dos fármacos , Pasteurelose Pneumônica/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Mannheimia haemolytica/fisiologia , Ovinos
14.
J Org Chem ; 85(2): 548-563, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31797669

RESUMO

A convergent strategy for the synthesis of multisubstituted pyridines is described. Vinylallenes combine with commercially available arylsulfonyl cyanides in Diels-Alder cycloadditions to generate isopyridine cycloadducts that are converted to pyridines upon further heating or addition of a base. The 2-sulfonylpyridine products undergo nucleophilic aromatic substitution reactions with oxygen and carbon nucleophiles to provide access to a variety of highly substituted pyridines.

15.
Int J Mol Sci ; 21(12)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580345

RESUMO

The treatment for ovarian cancers includes chemotherapies which use drugs such as cisplatin, paclitaxel, carboplatin, platinum, taxanes, or their combination, and other molecular target therapies. However, these current therapies are often accompanied with side effects. Vernonia calvoana (VC) is a valuable edible medicinal plant that is widespread in West Africa. In vitro data in our lab demonstrated that VC crude extract inhibits human ovarian cancer cells in a dose-dependent manner, suggesting its antitumor activity. From the VC crude extract, we have generated 10 fractions and VC fraction 7 (F7) appears to show the highest antitumor activity towards ovarian cancer cells. However, the mechanisms by which VC F7 exerts its antitumor activity in cancer cells remain largely unknown. We hypothesized that VC F7 inhibits cell proliferation and induces DNA damage and cell cycle arrest in ovarian cells through oxidative stress. To test our hypothesis, we extracted and fractionated VC leaves. The effects of VC F7 were tested in OVCAR-3 cells. Viability was assessed by the means of MTS assay. Cell morphology was analyzed by acridine orange and propidium iodide (AO/PI) dye using a fluorescent microscope. Oxidative stress biomarkers were evaluated by the means of lipid peroxidation, catalase, and glutathione peroxidase assays, respectively. The degree of DNA damage was assessed by comet assay. Cell cycle distribution was assessed by flow cytometry. Data generated from the MTS assay demonstrated that VC F7 inhibits the growth of OVCAR-3 cells in a dose-dependent manner, showing a gradual increase in the loss of viability in VC F7-treated cells. Data obtained from the AO/PI dye assessment revealed morphological alterations and exhibited characteristics such as loss of cellular membrane integrity, cell shrinkage, cell membrane damage, organelle breakdown, and detachment from the culture plate. We observed a significant increase (p < 0.05) in the levels of malondialdhyde (MDA) production in treated cells compared to the control. A gradual decrease in both catalase and glutathione peroxidase activities were observed in the treated cells compared to the control. Data obtained from the comet assay showed a significant increase (p < 0.05) in the percentages of DNA cleavage and comet tail length. The results of the flow cytometry analysis indicated VC F7 treatment caused cell cycle arrest at the S-phase checkpoint. Taken together, our results demonstrate that VC F7 exerts its anticancer activity by inhibiting cell proliferation, inducing DNA damage, and causing cell cycle arrest through oxidative stress in OVAR-3 cells. This finding suggests that VC F7 may be a potential alternative dietary agent for the prevention and/or treatment of ovarian cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Vernonia/química , Apoptose , Ciclo Celular , Proliferação de Células , Ensaio Cometa , Dano ao DNA , Feminino , Humanos , Neoplasias Ovarianas/patologia , Células Tumorais Cultivadas
16.
Molecules ; 25(24)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302377

RESUMO

Due to the emergence of multidrug-resistant pathogens, it is necessary to develop options to fight infections caused by these agents. Lactoferrin (Lf) is a cationic nonheme multifunctional glycoprotein of the innate immune system of mammals that provides numerous benefits. Lf is bacteriostatic and/or bactericidal, can stimulate cell proliferation and differentiation, facilitate iron absorption, improve neural development and cognition, promote bone growth, prevent cancer and exert anti-inflammatory and immunoregulatory effects. Lactoferrin is present in colostrum and milk and is also produced by the secondary granules of polymorphonuclear leukocytes, which store this glycoprotein and release it at sites of infection. Lf is also present in many fluids and exocrine secretions, on the surfaces of the digestive, respiratory and reproductive systems that are commonly exposed to pathogens. Apo-Lf (an iron-free molecule) can be microbiostatic due to its ability to capture ferric iron, blocking the availability of host iron to pathogens. However, apo-Lf is mostly microbicidal via its interaction with the microbial surface, causing membrane damage and altering its permeability function. Lf can inhibit viral entry by binding to cell receptors or viral particles. Lf is also able to counter different important mechanisms evolved by microbial pathogens to infect and invade the host, such as adherence, colonization, invasion, production of biofilms and production of virulence factors such as proteases and toxins. Lf can also cause mitochondrial and caspase-dependent regulated cell death and apoptosis-like in pathogenic yeasts. All of these mechanisms are important targets for treatment with Lf. Holo-Lf (the iron-saturated molecule) can contain up to two ferric ions and can also be microbicidal against some pathogens. On the other hand, lactoferricins (Lfcins) are peptides derived from the N-terminus of Lf that are produced by proteolysis with pepsin under acidic conditions, and they cause similar effects on pathogens to those caused by the parental Lf. Synthetic analog peptides comprising the N-terminus Lf region similarly exhibit potent antimicrobial properties. Importantly, there are no reported pathogens that are resistant to Lf and Lfcins; in addition, Lf and Lfcins have shown a synergistic effect with antimicrobial and antiviral drugs. Due to the Lf properties being microbiostatic, microbicidal, anti-inflammatory and an immune modulator, it represents an excellent natural alternative either alone or as adjuvant in the combat to antibiotic multidrug-resistant bacteria and other pathogens. This review aimed to evaluate the data that appeared in the literature about the effects of Lf and its derived peptides on pathogenic bacteria, protozoa, fungi and viruses and how Lf and Lfcins inhibit the mechanisms developed by these pathogens to cause disease.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Lactoferrina/química , Lactoferrina/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Animais , Anti-Infecciosos/síntese química , Antiparasitários/síntese química , Antiparasitários/química , Antiparasitários/farmacologia , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Técnicas de Química Sintética , Fungos/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Humanos , Peptídeos/síntese química , Proteólise/efeitos dos fármacos , Relação Estrutura-Atividade , Virulência/efeitos dos fármacos , Fatores de Virulência , Vírus/efeitos dos fármacos
17.
Exp Mol Pathol ; 108: 173-182, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31004600

RESUMO

Despite the lack of a complete understanding of the disparities involved, prostate cancer (PCa) has both higher incidence and death rates in African American Men (AAM) relative to those of Caucasian American Men (CAM). MHC class I polypeptide related sequence A (MICA) is an innate immunity protein involved in tumor immunoevasion. Due to a lack of reports of race-specific expression of MICA in PCa, we evaluated MICA expression in patients' tumors and in cell lines from a racially diverse origin. Immunohistochemistry was done on a tissue microarray (TMA) with antibodies against MICA. Tumor MICA mRNA was assessed by data mining using Oncomine and PROGeneV2. Surface MICA and release rate of soluble (s) MICA was evaluated in PCa cell lines originally derived from African American (MDA-PCa-2b) or Caucasian (LNCaP and DU-145) PCa patients. Prostate tumor tissue had a 1.7-fold higher MICA expression relative to normal tissue (p < .0001). MICA immunoreactivity in PCa tissue from AAM was 24% lower (p = .002) compared to CAM. Survival analysis revealed a marginal association of low MICA with poor overall survival (OS) (p = .058). By data mining analysis, a 2.9-fold higher level of MICA mRNA was evidenced in tumor compared to normal tissue (p < .0001). Tumors from AAM had 24% lower levels of MICA mRNA compared to tumors from CAM (p = .038), and poor prognosis was found for patients with lower MICA mRNA (p = .028). By flow cytometry analysis, cell fraction positive for surface MICA was of 3% in MDA-PCa-2b cells, 54% in DU-145 cells, and 67% in LNCaP cells (p < .0001). sMICA was detected in DU-145 and LNCaP cells, but was not detected in MDA-PCa-2b cells. Both LNCaP and DU-145 cells were sensitive to cytolysis mediated by Natural killer (NK) cells. MDA-PCa-2b cells, however were between 1.3-fold at 10:1 Effector:Target (E:T) ratio (p < .0001) and 2-fold at 50:1 E:T ratio (p < .0001) more resistant to NK-mediated cytolysis relative to cells from Caucasian origin. These results suggest that MICA expression may be related to the aggressive nature of PCa. Our findings also demonstrate for the first time that there are variations in MICA expression in the context of racial differences. This study establishes a rationale for further investigation of MICA as a potential race-specific prognostic marker in PCa.


Assuntos
Negro ou Afro-Americano/genética , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/genética , Neoplasias da Próstata/genética , População Branca/genética , Idoso , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Perfilação da Expressão Gênica/métodos , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/metabolismo , Análise de Sobrevida , Estados Unidos
18.
J Am Acad Dermatol ; 80(6): 1704-1711, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30716405

RESUMO

BACKGROUND: Follicular mucinosis (FM), which is defined by mucin accumulation within follicular epithelium, may occur in mycosis fungoides (MF). FM without MF is occasionally reported in systemic hematologic malignancies and may be diagnostically challenging. OBJECTIVE: To describe clinicopathologic characteristics of FM in patients with hematologic malignancies other than MF. METHODS: Clinical data and histopathology features were analyzed in patients with FM and hematologic malignancies diagnosed between 1994 and 2017. RESULTS: A total of 18 patients with FM and systemic hematologic malignancies without cutaneous T-cell lymphoma (CTCL) were identified; 9 of them were discovered after hematopoietic stem cell transplantation. No patients with non-CTCL-associated FM (n = 46 [37 biopsy specimens]) developed CTCL during a mean follow-up of 4.3 years. Of the cases of CTCL associated with FM (n = 44 [31 biopsy specimens]), MF was the most common subtype (n = 38), although other CTCLs were identified. FM in patients with non-CTCL hematologic malignancies differed clinically from those with MF-associated FM, presenting most frequently with erythematous papules (P < .0001), without plaques (P <.0001), without alopecia (P = .001), and without histopathologically identified epidermal exocytosis (P = .013). LIMITATIONS: A retrospective study in a single cancer center. CONCLUSIONS: FM can present in systemic hematologic malignancies, including after hematopoietic stem cell transplantation. Papular lesional morphologic and histopathologic features may help to distinguish these cases from MF.


Assuntos
Neoplasias Hematológicas/complicações , Mucinose Folicular/etiologia , Síndromes Paraneoplásicas/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Institutos de Câncer , Bases de Dados Factuais , Feminino , Seguimentos , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Humanos , Linfoma Cutâneo de Células T/complicações , Masculino , Pessoa de Meia-Idade , Mucinose Folicular/diagnóstico , Mucinose Folicular/patologia , Micose Fungoide/complicações , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/patologia , Estudos Retrospectivos , Pele/patologia , Neoplasias Cutâneas/complicações , Adulto Jovem
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