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1.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37047556

RESUMO

As emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants (Omicron) continue to outpace and negate combinatorial vaccines and monoclonal antibody therapies targeting the spike protein (S) receptor binding domain (RBD), the appetite for developing similar COVID-19 treatments has significantly diminished, with the attention of the scientific community switching to long COVID treatments. However, treatments that reduce the risk of "post-COVID-19 syndrome" and associated sequelae remain in their infancy, particularly as no established criteria for diagnosis currently exist. Thus, alternative therapies that reduce infection and prevent the broad range of symptoms associated with 'post-COVID-19 syndrome' require investigation. This review begins with an overview of the parasitic-diarylamidine connection, followed by the renin-angiotensin system (RAS) and associated angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSSR2) involved in SARS-CoV-2 infection. Subsequently, the ability of diarylamidines to inhibit S-protein binding and various membrane serine proteases associated with SARS-CoV-2 and parasitic infections are discussed. Finally, the roles of diarylamidines (primarily DIZE) in vaccine efficacy, epigenetics, and the potential amelioration of long COVID sequelae are highlighted.


Assuntos
COVID-19 , Humanos , SARS-CoV-2/metabolismo , Síndrome de COVID-19 Pós-Aguda , Peptidil Dipeptidase A/metabolismo , Sistema Renina-Angiotensina
2.
Neurochem Res ; 47(6): 1503-1512, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35298764

RESUMO

The bidirectional communication between the brain and peripheral organs have been widely documented, but the impact of visceral adipose tissue (VAT) dysfunction and its relation to structural and functional brain changes have yet to be fully elucidated. This review initially examines the clinical evidence supporting associations between the brain and VAT before visiting the roles of the autonomic nervous system, fat and glucose metabolism, neuroinflammation, and metabolites. Finally, the possible effects and potential mechanisms of the brain-VAT axis on the pathogenesis of Alzheimer's disease are discussed, providing new insights regarding future prevention and therapeutic strategies.


Assuntos
Doença de Alzheimer , Gordura Intra-Abdominal , Tecido Adiposo , Doença de Alzheimer/metabolismo , Encéfalo , Humanos , Gordura Intra-Abdominal/metabolismo , Gordura Intra-Abdominal/patologia
3.
Adv Exp Med Biol ; 1321: 3-19, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33656709

RESUMO

Within the last two decades, several members of the Coronaviridae family demonstrated epidemic potential. In late 2019, an unnamed genetic relative, later named SARS-CoV-2 (COVID-19), erupted in the highly populous neighborhoods of Wuhan, China. Unchecked, COVID-19 spread rapidly among interconnected communities and related households before containment measures could be enacted. At present, the mortality rate of COVID-19 infection worldwide is 6.6%. In order to mitigate the number of infections, restrictions or recommendations on the number of people that can gather in a given area have been employed by governments worldwide. For governments to confidently lift these restrictions as well as counter a potential secondary wave of infections, alternative medications and diagnostic strategies against COVID-19 are urgently required. This review has focused on these issues.


Assuntos
COVID-19 , Epidemias , China , Humanos , SARS-CoV-2
4.
Int J Mol Sci ; 22(7)2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33800682

RESUMO

Antibiotic and multi-drug resistant (MDR) Salmonella poses a significant threat to public health due to its ability to colonize animals (cold and warm-blooded) and contaminate freshwater supplies. Monitoring antibiotic resistant Salmonella is traditionally costly, involving the application of phenotypic and genotypic tests over several days. However, with the introduction of cheaper semi-automated devices in the last decade, strain detection and identification times have significantly fallen. This, in turn, has led to efficiently regulated food production systems and further reductions in food safety hazards. This review highlights current and emerging technologies used in the detection of antibiotic resistant and MDR Salmonella.


Assuntos
Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Infecções por Salmonella/tratamento farmacológico , Salmonella/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Gestão de Antimicrobianos , Técnicas Biossensoriais , Microbiologia de Alimentos , Inocuidade dos Alimentos , Genótipo , Humanos , Família Multigênica , Preparações Farmacêuticas , Fenótipo , Reação em Cadeia da Polimerase , Infecções por Salmonella/microbiologia , Análise Espectral Raman , Sequenciamento Completo do Genoma
5.
Nature ; 450(7171): 887-92, 2007 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-18004301

RESUMO

The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods-recursive partitioning and regression-to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; P(combined) = 2.01 x 10(-19) and 2.35 x 10(-13), respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/genética , Genes MHC Classe I/genética , Predisposição Genética para Doença/genética , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Alelos , Estudos de Casos e Controles , Bases de Dados Genéticas , Frequência do Gene , Genes MHC da Classe II/genética , Genótipo , Antígenos HLA-DQ/genética , Cadeias beta de HLA-DQ , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Polimorfismo de Nucleotídeo Único/genética , Tamanho da Amostra , População Branca/genética
6.
Antibiotics (Basel) ; 12(2)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36830133

RESUMO

Atopic Dermatitis (AD) skin is susceptible to Staphylococcus aureus (SA) infection, potentially exposing it to a plethora of toxins and virulent determinants, including Panton-Valentine leukocidin (PVL) (α-hemolysin (Hla) and phenol-soluble modulins (PSMs)), and superantigens. Depending on the degree of infection (superficial or invasive), clinical treatments may encompass permanganate (aq) and bleach solutions coupled with intravenous/oral antibiotics such as amoxicillin, vancomycin, doxycycline, clindamycin, daptomycin, telavancin, linezolid, or tigecycline. However, when the skin is significantly traumatized (sheathing of epidermal sections), an SA infection can rapidly ensue, impairing the immune system, and inducing local and systemic AD presentations in susceptible areas. Furthermore, when AD presents systemically, desensitization can be long (years) and intertwined with periods of relapse. In such circumstances, the identification of triggers (stress or infection) and severity of the flare need careful monitoring (preferably in real-time) so that tailored treatments targeting the underlying pathological mechanisms (SA toxins, elevated immunoglobulins, impaired healing) can be modified, permitting rapid resolution of symptoms.

7.
Cells ; 12(15)2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37566027

RESUMO

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease affecting the upper and lower motor neurons, leading to muscle weakness, motor impairments, disabilities and death. Approximately 5-10% of ALS cases are associated with positive family history (familial ALS or fALS), whilst the remainder are sporadic (sporadic ALS, sALS). At least 50 genes have been identified as causative or risk factors for ALS. Established pathogenic variants include superoxide dismutase type 1 (SOD1), chromosome 9 open reading frame 72 (c9orf72), TAR DNA Binding Protein (TARDBP), and Fused In Sarcoma (FUS); additional ALS-related genes including Charged Multivesicular Body Protein 2B (CHMP2B), Senataxin (SETX), Sequestosome 1 (SQSTM1), TANK Binding Kinase 1 (TBK1) and NIMA Related Kinase 1 (NEK1), have been identified. Mutations in these genes could impair different mechanisms, including vesicle transport, autophagy, and cytoskeletal or mitochondrial functions. So far, there is no effective therapy against ALS. Thus, early diagnosis and disease risk predictions remain one of the best options against ALS symptomologies. Proteomic biomarkers, microRNAs, and extracellular vehicles (EVs) serve as promising tools for disease diagnosis or progression assessment. These markers are relatively easy to obtain from blood or cerebrospinal fluids and can be used to identify potential genetic causative and risk factors even in the preclinical stage before symptoms appear. In addition, antisense oligonucleotides and RNA gene therapies have successfully been employed against other diseases, such as childhood-onset spinal muscular atrophy (SMA), which could also give hope to ALS patients. Therefore, an effective gene and biomarker panel should be generated for potentially "at risk" individuals to provide timely interventions and better treatment outcomes for ALS patients as soon as possible.


Assuntos
Esclerose Lateral Amiotrófica , Doenças Neurodegenerativas , Humanos , Criança , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/terapia , Esclerose Lateral Amiotrófica/metabolismo , Proteômica , Proteínas de Ligação a DNA/metabolismo , Superóxido Dismutase-1 , Biomarcadores , Fatores de Risco , DNA Helicases , RNA Helicases , Enzimas Multifuncionais
8.
Cells ; 12(20)2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37887303

RESUMO

A form of dementia distinct from healthy cognitive aging, Alzheimer's disease (AD) is a complex multi-stage disease that currently afflicts over 50 million people worldwide. Unfortunately, previous therapeutic strategies developed from murine models emulating different aspects of AD pathogenesis were limited. Consequently, researchers are now developing models that express several aspects of pathogenesis that better reflect the clinical situation in humans. As such, this review seeks to provide insight regarding current applications of mammalian models in AD research by addressing recent developments and characterizations of prominent transgenic models and their contributions to pathogenesis as well as discuss the advantages, limitations, and application of emerging models that better capture genetic heterogeneity and mixed pathologies observed in the clinical situation.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Doença de Alzheimer/patologia , Nível de Saúde , Mamíferos , Inquéritos e Questionários , Proteínas tau/genética
9.
Pharmaceutics ; 14(4)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35456638

RESUMO

Due to differences in geographic surveillance systems, chemical sanitization practices, and antibiotic stewardship (AS) implementation employed during the COVID-19 pandemic, many experts have expressed concerns regarding a future surge in global antimicrobial resistance (AMR). A potential beneficiary of these differences is the Gram-positive bacteria MRSA. MRSA is a bacterial pathogen with a high potential for mutational resistance, allowing it to engage various AMR mechanisms circumventing conventional antibiotic therapies and the host's immune response. Coupled with a lack of novel FDA-approved antibiotics reaching the clinic, the onus is on researchers to develop alternative treatment tools to mitigate against an increase in pathogenic resistance. Mitigation strategies can take the form of synthetic or biomimetic nanomaterials/vesicles employed in vaccines, rapid diagnostics, antibiotic delivery, and nanotherapeutics. This review seeks to discuss the current potential of the aforementioned nanomaterials in detecting and treating MRSA.

10.
J Nanosci Nanotechnol ; 9(10): 5731-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19908445

RESUMO

This paper describes a rapid imprinting procedure that makes it possible to imprint 2 and 3 dimensional DNA morphology in less than 30 minutes. In addition a multidimensional surface containing both micron and chaotic structures was successfully imprinted with a vertical and lateral resolution of 1 and 12 nm respectively. The speed and simplicity of this technique offers significant advantages compared with other techniques using polydimethylsiloxane. Moreover the process can be performed at room temperature and the master surface does not require any pretreatment or additional release agent. A polymer imprint of a polished silicon surface using thiolene based pre-polymer doped with polyethylene glycol exhibited a surface roughness value of 0.22 nm.


Assuntos
DNA/química , Conformação de Ácido Nucleico , Microscopia de Força Atômica
11.
Drug Des Devel Ther ; 13: 327-343, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30705582

RESUMO

The worldwide misuse of antibiotics and the subsequent rise of multidrug-resistant pathogenic bacteria have prompted a paradigm shift in the established view of antibiotic and bacterial-human relations. The clinical failures of conventional antibiotic therapies are associated with lengthy detection methods, poor penetration at infection sites, disruption of indigenous microflora and high potential for mutational resistance. One of the most promising strategies to improve the efficacy of antibiotics is to complex them with micro or nano delivery materials. Such materials/vehicles can shield antibiotics from enzyme deactivation, increasing the therapeutic effectiveness of the drug. Alternatively, drug-free nanomaterials that do not kill the pathogen but target virulent factors such as adhesins, toxins, or secretory systems can be used to minimize resistance and infection severity. The main objective of this review is to examine the potential of the aforementioned materials in the detection and treatment of antibiotic-resistant pathogenic organisms.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Antibacterianos/química , Infecções Bacterianas/microbiologia , Portadores de Fármacos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos
12.
Infect Drug Resist ; 12: 1597-1615, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354309

RESUMO

Clostridium difficile (C. difficile) is rapidly becoming one of the most prevalent health care-associated bacterial infections in the developed world. The emergence of new, more virulent strains has led to greater morbidity and resistance to standard therapies. The bacterium is readily transmitted between people where it can asymptomatically colonize the gut environment, and clinical manifestations ranging from frequent watery diarrhea to toxic megacolon can arise depending on the age of the individual or their state of gut dysbiosis. Several inexpensive approaches are shown to be effective against virulent C. difficile in research settings such as probiotics, fecal microbiota transfer and immunotherapies. This review aims to highlight the current advantages and limitations of the aforementioned approaches with an emphasis on recent studies.

14.
J Neurol Sci ; 395: 62-70, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30292965

RESUMO

Alzheimer's Disease (AD) is one of the most common age-related neurodegenerative diseases in the developed world. Treatment of AD is particularly challenging as the drug must overcome the blood brain barrier (BBB) before it can reach its target. Mitochondria are recognized as one of the most important targets for neurological drugs as the organelle is known to play a critical role in diverse cellular processes such as energy production and apoptosis regulation. Mitochondrial targeting was originally developed to study mitochondrial dysfunction and the organelles interaction with other sub-cellular organelles. The purpose of this review is to provide an overview of mitochondrial dysfunction and its role in late onset AD pathology. We then highlight recent antioxidant and enzymatic treatments used to alleviate mitochondrial dysfunction. Finally, we describe current applications of targeted mitochondrial delivery in the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/metabolismo , Animais , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo
15.
Nutrients ; 10(11)2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30441866

RESUMO

The bidirectional communication between the central nervous system (CNS) and the gut microbiota plays a pivotal role in human health. Increasing numbers of studies suggest that the gut microbiota can influence the brain and behavior of patients. Various metabolites secreted by the gut microbiota can affect the cognitive ability of patients diagnosed with neurodegenerative diseases. Nearly one in every ten Korean senior citizens suffers from Alzheimer's disease (AD), the most common form of dementia. This review highlights the impact of metabolites from the gut microbiota on communication pathways between the brain and gut, as well as the neuroinflammatory roles they may have in AD patients. The objectives of this review are as follows: (1) to examine the role of the intestinal microbiota in homeostatic communication between the gut microbiota and the brain, termed the microbiota⁻gut⁻brain (MGB) axis; (2) to determine the underlying mechanisms of signal dysfunction; and (3) to assess the impact of signal dysfunction induced by the microbiota on AD. This review will aid in understanding the microbiota of elderly people and the neuroinflammatory roles they may have in AD.


Assuntos
Doença de Alzheimer , Microbioma Gastrointestinal/fisiologia , Inflamação/microbiologia , Sistema Nervoso Central , Homeostase , Humanos , Inflamação/metabolismo
16.
BMC Med Genet ; 7: 20, 2006 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-16519819

RESUMO

BACKGROUND: The identification of the HLA class II, insulin (INS), CTLA-4 and PTPN22 genes as determinants of type 1 diabetes (T1D) susceptibility indicates that fine tuning of the immune system is centrally involved in disease development. Some genes have been shown to affect several immune-mediated diseases. Therefore, we tested the hypothesis that alleles of susceptibility genes previously associated with other immune-mediated diseases might perturb immune homeostasis, and hence also associate with predisposition to T1D. METHODS: We resequenced and genotyped tag single nucleotide polymorphisms (SNPs) from two genes, CRP and FCER1B, and genotyped 27 disease-associated polymorphisms from thirteen gene regions, namely FCRL3, CFH, SLC9A3R1, PADI4, RUNX1, SPINK5, IL1RN, IL1RA, CARD15, IBD5-locus (including SLC22A4), LAG3, ADAM33 and NFKB1. These genes have been associated previously with susceptibility to a range of immune-mediated diseases including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Graves' disease (GD), psoriasis, psoriatic arthritis (PA), atopy, asthma, Crohn disease and multiple sclerosis (MS). Our T1D collections are divided into three sample subsets, consisting of set 1 families (up to 754 families), set 2 families (up to 743 families), and a case-control collection (ranging from 1,500 to 4,400 cases and 1,500 to 4,600 controls). Each SNP was genotyped in one or more of these subsets. Our study typically had approximately 80% statistical power for a minor allele frequency (MAF) >5% and odds ratios (OR) of 1.5 with the type 1 error rate, alpha = 0.05. RESULTS: We found no evidence of association with T1D at most of the loci studied 0.02


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas ADAM/genética , Estudos de Casos e Controles , Humanos , Doenças do Sistema Imunitário/genética
17.
BMC Genet ; 7: 12, 2006 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-16504056

RESUMO

BACKGROUND: The aetiology of the autoimmune disease type 1 diabetes (T1D) involves many genetic and environmental factors. Evidence suggests that innate immune responses, including the action of interferons, may also play a role in the initiation and/or pathogenic process of autoimmunity. In the present report, we have adopted a linkage disequilibrium (LD) mapping approach to test for an association between T1D and three regions encompassing 13 interferon alpha (IFNA) genes, interferon omega-1 (IFNW1), interferon beta-1 (IFNB1), interferon gamma (IFNG) and the interferon consensus-sequence binding protein 1 (ICSBP1). RESULTS: We identified 238 variants, most, single nucleotide polymorphisms (SNPs), by sequencing IFNA, IFNB1, IFNW1 and ICSBP1, 98 of which where novel when compared to dbSNP build 124. We used polymorphisms identified in the SeattleSNP database for INFG. A set of tag SNPs was selected for each of the interferon and interferon-related genes to test for an association between T1D and this complex gene family. A total of 45 tag SNPs were selected and genotyped in a collection of 472 multiplex families. CONCLUSION: We have developed informative sets of SNPs for the interferon and interferon related genes. No statistical evidence of a major association between T1D and any of the interferon and interferon related genes tested was found.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Interferons/genética , Polimorfismo Genético , Doenças Autoimunes/genética , Bases de Dados Genéticas , Éxons , Saúde da Família , Feminino , Ligação Genética , Humanos , Interferon Tipo I/genética , Interferon-alfa/genética , Interferon beta/genética , Interferon gama/genética , Desequilíbrio de Ligação , Masculino , Modelos Estatísticos , Família Multigênica , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
18.
Drug Des Devel Ther ; 10: 2155-65, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27445462

RESUMO

Three-dimensional (3D) cell cultivation is a powerful technique for monitoring and understanding diverse cellular mechanisms in developmental cancer and neuronal biology, tissue engineering, and drug development. 3D systems could relate better to in vivo models than two-dimensional (2D) cultures. Several factors, such as cell type, survival rate, proliferation rate, and gene and protein expression patterns, determine whether a particular cell line can be adapted to a 3D system. The 3D system may overcome some of the limitations of 2D cultures in terms of cell-cell communication and cell networks, which are essential for understanding differentiation, structural organization, shape, and extended connections with other cells or organs. Here, the effect of the anticancer drug cisplatin, also known as cis-diamminedichloroplatinum (II) or CDDP, on adenosine triphosphate (ATP) generation was investigated using 3D spheroid-forming cells and real-time monitoring for 7 days. First, 12 cell lines were screened for their ability to form 3D spheroids: prostate (DU145), testis (F9), embryonic fibroblast (NIH-3T3), muscle (C2C12), embryonic kidney (293T), neuroblastoma (SH-SY5Y), adenocarcinomic alveolar basal epithelial cell (A549), cervical cancer (HeLa), HeLa contaminant (HEp2), pituitary epithelial-like cell (GH3), embryonic cell (PA317), and osteosarcoma (U-2OS) cells. Of these, eight cell lines were selected: NIH-3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U-2OS; and five underwent real-time monitoring of CDDP cytotoxicity: HeLa, A549, 293T, SH-SY5Y, and U-2OS. ATP generation was blocked 1 day after addition of 50 µM CDDP, but cytotoxicity in HeLa, A549, SH-SY5Y, and U-2OS cells could be visualized only 4 days after treatment. In 293T cells, CDDP failed to kill entirely the culture and ATP generation was only partially blocked after 1 day. This suggests potential CDDP resistance of 293T cells or metabolic clearance of the drug. Real-time monitoring and ATP measurements directly confirmed the cytotoxicity of CDDP, indicating that CDDP may interfere with mitochondrial activity.


Assuntos
Trifosfato de Adenosina/química , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Cisplatino/farmacologia , Cisplatino/toxicidade , Antineoplásicos/química , Técnicas de Cultura de Células , Cisplatino/química , Células HeLa , Humanos , Fatores de Tempo
19.
Drug Des Devel Ther ; 10: 3363-3378, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27789937

RESUMO

The aim of this study was to investigate the bacteriostatic and bactericidal effects of diminazene aceturate (DA) against five strains of pathogenic bacteria and two strains of nonpathogenic bacteria. The results showed that 5 µg/mL of DA suppressed the growth of pathogenic Escherichia coli by as much as 77% compared with the controls. Enterohemorrhagic E. coli EDL933 (an E. coli O157:H7 strain) was the most sensitive to DA with a minimum inhibitory concentration of 20 µg/mL. Additional investigations showed that DA induced the highest level of intracellular reactive oxygen species in EDL933. A positive correlation between the reactive oxygen species levels and DA concentration was demonstrated. DA (5 µg/mL) was also a potent uncoupler, inducing a stationary phase collapse (70%-75%) in both strains of E. coli O157:H7. Further investigation showed that the collapse was due to the NaCl:DA ratio in the broth and was potassium ion dependent. A protease screening assay was conducted to elucidate the underlying mechanism. It was found that at neutral pH, the hydrolysis of H-Asp-pNA increased by a factor of 2-3 in the presence of DA, implying that DA causes dysregulation of the proton motive force and a decrease in cellular pH. Finally, a commercial verotoxin test showed that DA did not significantly increase toxin production in EDL933 and was a suitable antibacterial agent for Shiga-toxin-producing E. coli.


Assuntos
Antibacterianos/farmacologia , Diminazena/análogos & derivados , Escherichia coli O157/efeitos dos fármacos , Peptídeo Hidrolases/química , Toxina Shiga/antagonistas & inibidores , Toxinas Shiga/efeitos adversos , Antibacterianos/química , Diminazena/química , Diminazena/farmacologia , Escherichia coli O157/química , Ensaios de Triagem em Larga Escala , Toxinas Shiga/química
20.
Onco Targets Ther ; 9: 7207-7218, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27920558

RESUMO

Recently, increasing numbers of cell culture experiments with 3D spheroids presented better correlating results in vivo than traditional 2D cell culture systems. 3D spheroids could offer a simple and highly reproducible model that would exhibit many characteristics of natural tissue, such as the production of extracellular matrix. In this paper numerous cell lines were screened and selected depending on their ability to form and maintain a spherical shape. The effects of increasing concentrations of doxorubicin (DXR) on the integrity and viability of the selected spheroids were then measured at regular intervals and in real-time. In total 12 cell lines, adenocarcinomic alveolar basal epithelial (A549), muscle (C2C12), prostate (DU145), testis (F9), pituitary epithelial-like (GH3), cervical cancer (HeLa), HeLa contaminant (HEp2), embryo (NIH3T3), embryo (PA317), neuroblastoma (SH-SY5Y), osteosarcoma U2OS, and embryonic kidney cells (293T), were screened. Out of the 12, 8 cell lines, NIH3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U2OS formed regular spheroids and the effects of DXR on these structures were measured at regular intervals. Finally, 5 cell lines, A549, HeLa, SH-SY5Y, U2OS, and 293T, were selected for real-time monitoring and the effects of DXR treatment on their behavior were continuously recorded for 5 days. A potential correlation regarding the effects of DXR on spheroid viability and ATP production was measured on days 1, 3, and 5. Cytotoxicity of DXR seemed to occur after endocytosis, since the cellular activities and ATP productions were still viable after 1 day of the treatment in all spheroids, except SH-SY5Y. Both cellular activity and ATP production were halted 3 and 5 days from the start of the treatment in all spheroids. All cell lines maintained their spheroid shape, except SHSY-5, which behaved in an unpredictable manner when exposed to toxic concentrations of DXR. Cytotoxic effects of DXR towards SH-SY5Y seemed to cause degradation of the extracellular matrix, since all cells were dismantled from the spheroid upon cell death. On the other hand, 293T spheroids revealed retarded cellular activity and ATP productions upon DXR treatment throughout the experiment. Since 293T was the embryonic kidney cells, the fast clearance or neutralizations could have made them resistant towards DXR. In conclusion, the same degree of sensitivity from the 2D system did not translate to a 3D culture system, resulting in higher IC50 values than the 2D system. The varying sensitivities and tolerances to drugs could be better understood with a 3D cell culture system.

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