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1.
Front Immunol ; 15: 1324045, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38390324

RESUMO

MYC activation is a known hallmark of cancer as it governs the gene targets involved in various facets of cancer progression. Of interest, MYC governs oncometabolism through the interactions with its partners and cofactors, as well as cancer immunity via its gene targets. Recent investigations have taken interest in characterizing these interactions through multi-Omic approaches, to better understand the vastness of the MYC network. Of the several gene targets of MYC involved in either oncometabolism or oncoimmunology, few of them overlap in function. Prominent interactions have been observed with MYC and HIF-1α, in promoting glucose and glutamine metabolism and activation of antigen presentation on regulatory T cells, and its subsequent metabolic reprogramming. This review explores existing knowledge of the role of MYC in oncometabolism and oncoimmunology. It also unravels how MYC governs transcription and influences cellular metabolism to facilitate the induction of pro- or anti-tumoral immunity. Moreover, considering the significant roles MYC holds in cancer development, the present study discusses effective direct or indirect therapeutic strategies to combat MYC-driven cancer progression.


Assuntos
Neoplasias , Proteínas Proto-Oncogênicas c-myc , Humanos , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Glicólise
2.
Hepatol Commun ; 6(10): 2702-2714, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35866580

RESUMO

Biliary atresia (BA) is a neonatal inflammatory cholangiopathy that requires surgical intervention by Kasai portoenterostomy to restore biliary drainage. Even with successful portoenterostomy, most patients diagnosed with BA progress to end-stage liver disease, necessitating a liver transplantation for survival. In the murine model of BA, rhesus rotavirus (RRV) infection of neonatal mice induces an inflammatory obstructive cholangiopathy that parallels human BA. The model is triggered by RRV viral protein (VP)4 binding to cholangiocyte cell-surface proteins. High mobility group box 1 (HMGB1) protein is a danger-associated molecular pattern that when released extracellularly moderates innate and adaptive immune response. In this study, we investigated how mutations in three RRV VP4-binding sites, RRVVP4-K187R (sialic acid-binding site), RRVVP4-D308A (integrin α2ß1-binding site), and RRVVP4-R446G (heat shock cognate 70 [Hsc70]-binding site), affects infection, HMGB1 release, and the murine model of BA. Newborn pups injected with RRVVP4-K187R and RRVVP4-D308A developed an obstruction within the extrahepatic bile duct similar to wild-type RRV, while those infected with RRVVP4-R446G remained patent. Infection with RRVVP4-R446G induced a lower level of HMGB1 release from cholangiocytes and in the serum of infected pups. RRV infection of HeLa cells lacking Hsc70 resulted in no HMGB1 release, while transfection with wild-type Hsc70 into HeLa Hsc70-deficient cells reestablished HMGB1 release, indicating a mechanistic role for Hsc70 in its release. Conclusion: Binding to Hsc70 contributes to HMGB1 release; therefore, Hsc70 potentially serves as a therapeutic target for BA.


Assuntos
Atresia Biliar , Infecções por Rotavirus , Rotavirus , Animais , Animais Recém-Nascidos , Atresia Biliar/etiologia , Sítios de Ligação , Modelos Animais de Doenças , Células HeLa , Humanos , Integrina alfa2beta1 , Macaca mulatta , Camundongos , Camundongos Endogâmicos BALB C , Ácido N-Acetilneuramínico , Rotavirus/genética , Infecções por Rotavirus/metabolismo , Proteínas Virais
3.
Neuropsychopharmacology ; 47(12): 2033-2041, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35354897

RESUMO

Antipsychotic drugs (APDs) are effective in treating positive symptoms of schizophrenia (SCZ). However, they have a substantial impact on postmortem studies. As most cohorts lack samples from drug-naive patients, many studies, rather than understanding SCZ pathophysiology, are analyzing the drug effects. We hypothesized that comparing SCZ-altered and APD-influenced signatures derived from the same cohort can provide better insight into SCZ pathophysiology. For this, we performed LCMS-based proteomics on dorsolateral prefrontal cortex (DLPFC) samples from control and SCZ subjects and used statistical approaches to identify SCZ-altered and APD-influenced proteomes, validated experimentally using independent cohorts and published datasets. Functional analysis of both proteomes was contrasted at the biological-pathway, cell-type, subcellular-synaptic, and drug-target levels. In silico validation revealed that the SCZ-altered proteome was conserved across several studies from the DLPFC and other brain areas. At the pathway level, SCZ influenced changes in homeostasis, signal-transduction, cytoskeleton, and dendrites, whereas APD influenced changes in synaptic-signaling, neurotransmitter-regulation, and immune-system processes. At the cell-type level, the SCZ-altered and APD-influenced proteomes were associated with two distinct striatum-projecting layer-5 pyramidal neurons regulating dopaminergic-secretion. At the subcellular synaptic level, compensatory pre- and postsynaptic events were observed. At the drug-target level, dopaminergic processes influenced the SCZ-altered upregulated-proteome, whereas nondopaminergic and a diverse array of non-neuromodulatory mechanisms influenced the downregulated-proteome. Previous findings were not independent of the APD effect and thus require re-evaluation. We identified a hyperdopaminergic cortex and drugs targeting the cognitive SCZ-symptoms and discussed their influence on SCZ pathology in the context of the cortico-striatal pathway.


Assuntos
Antipsicóticos , Esquizofrenia , Antipsicóticos/farmacologia , Antipsicóticos/uso terapêutico , Encéfalo/metabolismo , Dopamina/metabolismo , Humanos , Córtex Pré-Frontal/metabolismo , Proteoma/metabolismo , Proteômica , Esquizofrenia/metabolismo
4.
PLoS One ; 16(12): e0260440, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34919543

RESUMO

Phosphorylation by serine-threonine and tyrosine kinases is critical for determining protein function. Array-based platforms for measuring reporter peptide signal levels allow for differential phosphorylation analysis between conditions for distinct active kinases. Peptide array technologies like the PamStation12 from PamGene allow for generating high-throughput, multi-dimensional, and complex functional proteomics data. As the adoption rate of such technologies increases, there is an imperative need for software tools that streamline the process of analyzing such data. We present Kinome Random Sampling Analyzer (KRSA), an R package and R Shiny web-application for analyzing kinome array data to help users better understand the patterns of functional proteomics in complex biological systems. KRSA is an All-In-One tool that reads, formats, fits models, analyzes, and visualizes PamStation12 kinome data. While the underlying algorithm has been experimentally validated in previous publications, we demonstrate KRSA workflow on dorsolateral prefrontal cortex (DLPFC) in male (n = 3) and female (n = 3) subjects to identify differential phosphorylation signatures and upstream kinase activity. Kinase activity differences between males and females were compared to a previously published kinome dataset (11 female and 7 male subjects) which showed similar global phosphorylation signals patterns.


Assuntos
Córtex Pré-Frontal Dorsolateral/enzimologia , Família Multigênica , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Software , Algoritmos , Autopsia , Benchmarking , Conjuntos de Dados como Assunto , Córtex Pré-Frontal Dorsolateral/química , Feminino , Expressão Gênica , Humanos , Masculino , Fosfoproteínas/classificação , Fosfoproteínas/genética , Fosforilação , Análise de Componente Principal , Análise Serial de Proteínas , Proteínas Serina-Treonina Quinases/classificação , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/classificação , Proteínas Tirosina Quinases/genética , Proteômica/métodos
5.
PLoS One ; 16(6): e0244341, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34166366

RESUMO

BACKGROUND: Exposure to particulate matter has been shown to increase the adhesion of bacteria to human airway epithelial cells. However, the impact of traffic-related air pollution (TRAP) on the respiratory microbiome is unknown. METHODS: Forty children were recruited through the Cincinnati Childhood Allergy and Air Pollution Study, a longitudinal cohort followed from birth through early adolescence. Saliva and induced sputum were collected at age 14 years. Exposure to TRAP was characterized from birth through the time of sample collection using a previously validated land-use regression model. Sequencing of the bacterial 16S and ITS fungal rRNA genes was performed on sputum and saliva samples. The relative abundance of bacterial taxa and diversity indices were compared in children with exposure to high and low TRAP. We also used multiple linear regression to assess the effect of TRAP exposure, gender, asthma status, and socioeconomic status on the alpha diversity of bacteria in sputum. RESULTS: We observed higher bacterial alpha diversity indices in sputum than in saliva. The diversity indices for bacteria were greater in the high TRAP exposure group than the low exposure group. These differences remained after adjusting for asthma status, gender, and mother's education. No differences were observed in the fungal microbiome between TRAP exposure groups. CONCLUSION: Our findings indicate that exposure to TRAP in early childhood and adolescence may be associated with greater bacterial diversity in the lower respiratory tract. Asthma status does not appear to confound the observed differences in diversity. These results demonstrate that there may be a TRAP-exposure related change in the lower respiratory microbiota that is independent of asthma status.


Assuntos
Poluição do Ar/efeitos adversos , Asma/fisiopatologia , Bactérias/classificação , Carga Bacteriana/estatística & dados numéricos , Exposição Ambiental/efeitos adversos , Doenças Respiratórias/microbiologia , Poluição Relacionada com o Tráfego/efeitos adversos , Adolescente , Bactérias/genética , Bactérias/isolamento & purificação , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Metagenoma , Doenças Respiratórias/epidemiologia , Saliva/microbiologia , Escarro/microbiologia , Emissões de Veículos
6.
Neuropsychopharmacology ; 46(1): 116-130, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32604402

RESUMO

CNS disorders, and in particular psychiatric illnesses, lack definitive disease-altering therapeutics. The limited understanding of the mechanisms driving these illnesses with the slow pace and high cost of drug development exacerbates this issue. For these reasons, drug repurposing - both a less expensive and time-efficient practice compared to de novo drug development - has been a promising strategy to overcome the paucity of treatments available for these debilitating disorders. While empirical drug-repurposing has been a routine practice in clinical psychiatry, innovative, informed, and cost-effective repurposing efforts using big data ("omics") have been designed to characterize drugs by structural and transcriptomic signatures. These strategies, in conjunction with ontological integration, provide an important opportunity to address knowledge-based challenges associated with drug development for CNS disorders. In this review, we discuss various signature-based in silico approaches to drug repurposing, its integration with multiple omics platforms, and how this data can be used for clinically relevant, evidence-based drug repurposing. These tools provide an exciting translational avenue to merge omics-based drug discovery platforms with patient-specific disease signatures, ultimately facilitating the identification of new therapies for numerous psychiatric disorders.


Assuntos
Descoberta de Drogas , Reposicionamento de Medicamentos , Biologia Computacional , Simulação por Computador , Desenvolvimento de Medicamentos , Humanos
7.
Sci Total Environ ; 610-611: 212-218, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28803198

RESUMO

"Green" housing is designed to use low-impact materials, increase energy efficiency and improve occupant health. However, little is known about the indoor mycobiome of green homes. The current study is a subset of a multicenter study that aims to investigate the indoor environment of green homes and the respiratory health of asthmatic children. In the current study, the mycobiome in air, bed dust and floor dust was compared between green (study site) and non-green (control site), low-income homes in Cincinnati, Ohio. The samples were collected at baseline (within four months following renovation), and 12months after the baseline at the study site. Parallel sample collection was conducted in non-green control homes. Air samples were collected by PM2.5 samplers over 5-days. Bed and floor dust samples were vacuumed after the air sampling was completed. The DNA sample extracts were analyzed using ITS amplicon sequencing. Analysis indicated that there was no clear trend in the fungal communities between green and non-green homes. Instead, fungal community differences were greatest between sample types - air, bed, and floor. Microbial communities also changed substantially between sampling intervals in both green and non-green homes for all sample types, potentially indicating that there was very little stability in the mycobiomes. Research gaps remain regarding how indoor mycobiome fluctuates over time. Longer follow-up periods might elucidate the effect of green renovation on microbial load in buildings.


Assuntos
Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Habitação , Micobioma , Poeira , Humanos , Renda , Ohio , Áreas de Pobreza
8.
Cell Syst ; 6(1): 13-24, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29199020

RESUMO

The Library of Integrated Network-Based Cellular Signatures (LINCS) is an NIH Common Fund program that catalogs how human cells globally respond to chemical, genetic, and disease perturbations. Resources generated by LINCS include experimental and computational methods, visualization tools, molecular and imaging data, and signatures. By assembling an integrated picture of the range of responses of human cells exposed to many perturbations, the LINCS program aims to better understand human disease and to advance the development of new therapies. Perturbations under study include drugs, genetic perturbations, tissue micro-environments, antibodies, and disease-causing mutations. Responses to perturbations are measured by transcript profiling, mass spectrometry, cell imaging, and biochemical methods, among other assays. The LINCS program focuses on cellular physiology shared among tissues and cell types relevant to an array of diseases, including cancer, heart disease, and neurodegenerative disorders. This Perspective describes LINCS technologies, datasets, tools, and approaches to data accessibility and reusability.


Assuntos
Catalogação/métodos , Biologia de Sistemas/métodos , Biologia Computacional/métodos , Bases de Dados de Compostos Químicos/normas , Perfilação da Expressão Gênica/métodos , Biblioteca Gênica , Humanos , Armazenamento e Recuperação da Informação/métodos , Programas Nacionais de Saúde , National Institutes of Health (U.S.)/normas , Transcriptoma , Estados Unidos
9.
Biomed Inform Insights ; 9: 1178222617713018, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28634427

RESUMO

The objective of this study was to determine whether the Food and Drug Administration's Adverse Event Reporting System (FAERS) data set could serve as the basis of automated electronic health record (EHR) monitoring for the adverse drug reaction (ADR) subset of adverse drug events. We retrospectively collected EHR entries for 71 909 pediatric inpatient visits at Cincinnati Children's Hospital Medical Center. Natural language processing (NLP) techniques were used to identify positive diseases/disorders and signs/symptoms (DDSSs) from the patients' clinical narratives. We downloaded all FAERS reports submitted by medical providers and extracted the reported drug-DDSS pairs. For each patient, we aligned the drug-DDSS pairs extracted from their clinical notes with the corresponding drug-DDSS pairs from the FAERS data set to identify Drug-Reaction Pair Sentences (DRPSs). The DRPSs were processed by NLP techniques to identify ADR-related DRPSs. We used clinician annotated, real-world EHR data as reference standard to evaluate the proposed algorithm. During evaluation, the algorithm achieved promising performance and showed great potential in identifying ADRs accurately for pediatric patients.

10.
J Virol ; 91(15)2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28515290

RESUMO

Rotavirus infection is one of the most common causes of diarrheal illness in humans. In neonatal mice, rhesus rotavirus (RRV) can induce biliary atresia (BA), a disease resulting in inflammatory obstruction of the extrahepatic biliary tract and intrahepatic bile ducts. We previously showed that the amino acid arginine (R) within the sequence SRL (amino acids 445 to 447) in the RRV VP4 protein is required for viral binding and entry into biliary epithelial cells. To determine if this single amino acid (R) influences the pathogenicity of the virus, we generated a recombinant virus with a single amino acid mutation at this site through a reverse genetics system. We demonstrated that the RRV mutant (RRVVP4-R446G) produced less symptomatology and replicated to lower titers both in vivo and in vitro than those seen with wild-type RRV, with reduced binding in cholangiocytes. Our results demonstrate that a single amino acid change in the RRV VP4 gene influences cholangiocyte tropism and reduces pathogenicity in mice.IMPORTANCE Rotavirus is the leading cause of diarrhea in humans. Rhesus rotavirus (RRV) can also lead to biliary atresia (a neonatal human disease) in mice. We developed a reverse genetics system to create a mutant of RRV (RRVVP4-R446G) with a single amino acid change in the VP4 protein compared to that of wild-type RRV. In vitro, the mutant virus had reduced binding and infectivity in cholangiocytes. In vivo, it produced fewer symptoms and lower mortality in neonatal mice, resulting in an attenuated form of biliary atresia.


Assuntos
Atresia Biliar/patologia , Proteínas do Capsídeo/genética , Proteínas Mutantes/genética , Mutação Puntual , Rotavirus/patogenicidade , Animais , Animais Recém-Nascidos , Atresia Biliar/virologia , Proteínas do Capsídeo/metabolismo , Modelos Animais de Doenças , Camundongos , Proteínas Mutantes/metabolismo , Genética Reversa , Rotavirus/genética , Tropismo Viral , Replicação Viral
11.
J Neurotrauma ; 34(1): 220-234, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27312729

RESUMO

We hypothesize that the primary mechanism for removal of glutamate from the extracellular space is altered after traumatic brain injury (TBI). To evaluate this hypothesis, we initiated TBI in adult male rats using a 2.0 atm lateral fluid percussion injury (LFPI) model. In the ipsilateral cortex and hippocampus, we found no differences in expression of the primary glutamate transporter in the brain (GLT-1) 24 h after TBI. In contrast, we found a decrease in glutamate uptake in the cortex, but not the hippocampus, 24 h after injury. Because glutamate uptake is potently regulated by protein kinases, we assessed global serine-threonine protein kinase activity using a kinome array platform. Twenty-five kinome array peptide substrates were differentially phoshorylated between LFPI and controls in the cortex, whereas 19 peptide substrates were differentially phosphorylated in the hippocampus (fold change ≥ ± 1.15). We identified several kinases as likely to be involved in acute TBI, including protein kinase B (Akt) and protein kinase C (PKC), which are well-characterized modulators of GLT-1. Exploratory studies using an inhibitor of Akt suggest selective activation of kinases in LFPI versus controls. Ingenuity pathway analyses of implicated kinases from our network model found apoptosis and cell death pathways as top functions in acute LFPI. Taken together, our data suggest diminished activity of glutamate transporters in the prefrontal cortex, with no changes in protein expression of the primary glutamate transporter GLT-1, and global alterations in signaling networks that include serine-threonine kinases that are known modulators of glutamate transport activity.


Assuntos
Lesões Encefálicas Traumáticas/metabolismo , Córtex Cerebral/metabolismo , Transportador 2 de Aminoácido Excitatório/biossíntese , Ácido Glutâmico/metabolismo , Animais , Lesões Encefálicas Traumáticas/genética , Transportador 2 de Aminoácido Excitatório/genética , Expressão Gênica , Masculino , Ratos , Ratos Sprague-Dawley
12.
Hepatology ; 65(4): 1278-1292, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27859498

RESUMO

Biliary atresia (BA) is a neonatal obstructive cholangiopathy that progresses to end-stage liver disease, often requiring transplantation. The murine model of BA, employing rhesus rotavirus (RRV), parallels human disease and has been used to elucidate mechanistic aspects of a virus induced biliary cholangiopathy. We previously reported that the RRV VP4 gene plays an integral role in activating the immune system and induction of BA. Using rotavirus binding and blocking assays, this study elucidated how RRV VP4 protein governs cholangiocyte susceptibility to infection both in vitro and in vivo in the murine model of BA. We identified the amino acid sequence on VP4 and its cholangiocyte binding protein, finding that the sequence is specific to those rotavirus strains that cause obstructive cholangiopathy. Pretreatment of murine and human cholangiocytes with this VP4-derived peptide (TRTRVSRLY) significantly reduced the ability of RRV to bind and infect cells. However, the peptide did not block cholangiocyte binding of TUCH and Ro1845, strains that do not induce murine BA. The SRL sequence within TRTRVSRLY is required for cholangiocyte binding and viral replication. The cholangiocyte membrane protein bound by SRL was found to be Hsc70. Inhibition of Hsc70 by small interfering RNAs reduced RRV's ability to infect cholangiocytes. This virus-cholangiocyte interaction is also seen in vivo in the murine model of BA, where inoculation of mice with TRTRVSRLY peptide significantly reduced symptoms and mortality in RRV-injected mice. CONCLUSION: The tripeptide SRL on RRV VP4 binds to the cholangiocyte membrane protein Hsc70, defining a novel binding site governing VP4 attachment. Investigations are underway to determine the cellular response to this interaction to understand how it contributes to the pathogenesis of BA. (Hepatology 2017;65:1278-1292).


Assuntos
Atresia Biliar/genética , Proteínas do Capsídeo/genética , Colangite/genética , Rotavirus/patogenicidade , Animais , Animais Recém-Nascidos , Ductos Biliares/citologia , Atresia Biliar/virologia , Células Cultivadas , Colangite/virologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Macaca mulatta , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Aleatória , Rotavirus/genética , Infecções por Rotavirus/patologia , Infecções por Rotavirus/fisiopatologia , Ligação Viral , Replicação Viral
13.
Protein Sci ; 25(1): 135-46, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26073558

RESUMO

Switches form a special class of proteins that dramatically change their three-dimensional structures upon a small perturbation. One possible perturbation that we explore is that of a single point mutation. Building on the pioneering experimental work of Alexander et al. (Alexander et al. PNAS, 2007; 104,11963-11968) that determines switch sequences between α and α+ß folds we conduct a comprehensive sequence sampling by a Markov Chain with multiple fitness criteria to identify new switches given the experimental folds. We screen for switch sequences using a combination of contact potential, secondary structure prediction, and finally molecular dynamics simulations. Statistical properties of switch sequences are discussed and illustrated to be most sensitive to mutation at the N- and C- termini of the switch protein. Based on this analysis, a particularly stable putative switch pair is identified and proposed for further experimental analysis.


Assuntos
Simulação de Dinâmica Molecular , Proteínas/química , Sequência de Aminoácidos , Cadeias de Markov , Dobramento de Proteína , Estrutura Secundária de Proteína
14.
Am J Physiol Gastrointest Liver Physiol ; 309(6): G466-74, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26206856

RESUMO

Biliary atresia (BA), a neonatal obstructive cholangiopathy, remains the most common indication for pediatric liver transplantation in the United States. In the murine model of BA, Rhesus rotavirus (RRV) VP4 surface protein determines biliary duct tropism. In this study, we investigated how VP4 governs induction of murine BA. Newborn mice were injected with 16 strains of rotavirus and observed for clinical symptoms of BA and mortality. Cholangiograms were performed to confirm bile duct obstruction. Livers and bile ducts were harvested 7 days postinfection for virus titers and histology. Flow cytometry assessed mononuclear cell activation in harvested cell populations from the liver. Cytotoxic NK cell activity was determined by the ability of NK cells to kill noninfected cholangiocytes. Of the 16 strains investigated, the 6 with the highest homology to the RRV VP4 (>87%) were capable of infecting bile ducts in vivo. Although the strain Ro1845 replicated to a titer similar to RRV in vivo, it caused no symptoms or mortality. A Ro1845 reassortant containing the RRV VP4 induced all BA symptoms, with a mortality rate of 89%. Flow cytometry revealed that NK cell activation was significantly increased in the disease-inducing strains and these NK cells demonstrated a significantly higher percentage of cytotoxicity against noninfected cholangiocytes. Rotavirus strains with >87% homology to RRV's VP4 were capable of infecting murine bile ducts in vivo. Development of murine BA was mediated by RRV VP4-specific activation of mononuclear cells, independent of viral titers.


Assuntos
Atresia Biliar/patologia , Proteínas do Capsídeo/genética , Colestase/patologia , Leucócitos Mononucleares/fisiologia , Ativação de Macrófagos/fisiologia , Infecções por Rotavirus/patologia , Rotavirus/genética , Animais , Ductos Biliares/virologia , Ductos Biliares Extra-Hepáticos/patologia , Interferon gama/metabolismo , Células Matadoras Naturais/patologia , Fígado/patologia , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Infecções por Rotavirus/mortalidade , Ensaio de Placa Viral , Replicação Viral
15.
J Biol Chem ; 290(20): 12879-98, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25825487

RESUMO

The Ras family small GTPases regulate multiple cellular processes, including cell growth, survival, movement, and gene expression, and are intimately involved in cancer pathogenesis. Activation of these small GTPases is catalyzed by a special class of enzymes, termed guanine nucleotide exchange factors (GEFs). Herein, we developed a small molecule screening platform for identifying lead hits targeting a Ras GEF enzyme, SOS1. We employed an ensemble structure-based virtual screening approach in combination with a multiple tier high throughput experimental screen utilizing two complementary fluorescent guanine nucleotide exchange assays to identify small molecule inhibitors of GEF catalytic activity toward Ras. From a library of 350,000 compounds, we selected a set of 418 candidate compounds predicted to disrupt the GEF-Ras interaction, of which dual wavelength GDP dissociation and GTP-loading experimental screening identified two chemically distinct small molecule inhibitors. Subsequent biochemical validations indicate that they are capable of dose-dependently inhibiting GEF catalytic activity, binding to SOS1 with micromolar affinity, and disrupting GEF-Ras interaction. Mutagenesis studies in conjunction with structure-activity relationship studies mapped both compounds to different sites in the catalytic pocket, and both inhibited Ras signaling in cells. The unique screening platform established here for targeting Ras GEF enzymes could be broadly useful for identifying lead inhibitors for a variety of small GTPase-activating GEF reactions.


Assuntos
Inibidores Enzimáticos , Proteínas Ativadoras de ras GTPase/antagonistas & inibidores , Fatores ras de Troca de Nucleotídeo Guanina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/metabolismo , Fatores ras de Troca de Nucleotídeo Guanina/genética , Fatores ras de Troca de Nucleotídeo Guanina/metabolismo
16.
Am J Physiol Cell Physiol ; 308(1): C51-60, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25318106

RESUMO

In silico analysis predicts interaction between Na-K-ATPase (NKA) and Bcl-2 protein canonical BH3- and BH1-like motifs, consistent with NKA inhibition by the benzo-phenanthridine alkaloid chelerythrine, a BH3 mimetic, in fetal human lens epithelial cells (FHLCs) (Lauf PK, Heiny J, Meller J, Lepera MA, Koikov L, Alter GM, Brown TL, Adragna NC. Cell Physiol Biochem 31: 257-276, 2013). This report establishes proof of concept: coimmunoprecipitation and immunocolocalization showed unequivocal and direct physical interaction between NKA and Bcl-2 proteins. Specifically, NKA antibodies (ABs) coimmunoprecipitated BclXL (B-cell lymphoma extra large) and BAK (Bcl-2 antagonist killer) proteins in FHLCs and A549 lung cancer cells. In contrast, both anti-Bcl-2 ABs failed to pull down NKA. Notably, the molecular mass of BAK1 proteins pulled down by NKA and BclXL ABs appeared to be some 4-kDa larger than found in input monomers. In silico analysis predicts these higher molecular mass BAK1 proteins as alternative splicing variants, encoding 42 amino acid (aa) larger proteins than the known 211-aa long canonical BAK1 protein. These BAK1 variants may constitute a pool separate from that forming mitochondrial pores by specifically interacting with NKA and BclXL proteins. We propose a NKA-Bcl-2 protein ternary complex supporting our hypothesis for a special sensor role of NKA in Bcl-2 protein control of cell survival and apoptosis.


Assuntos
Células Epiteliais/enzimologia , Cristalino/enzimologia , Neoplasias Pulmonares/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismo , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Simulação por Computador , Bases de Dados de Proteínas , Imunofluorescência , Humanos , Imunoprecipitação , Cristalino/citologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Transdução de Sinais
17.
Pharmacogenomics ; 15(14): 1749-1762, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25493568

RESUMO

Background: Respiratory depression is a clinically and economically important but preventable complication of opioids. Genetic factors can help identify patients with high risk for respiratory depression. Methods: In this prospective genotype blinded clinical study, we evaluated the effect of a panel of variants in candidate genes on opioid-related respiratory depression in 347 children following tonsillectomy. Results: Using unsupervised hierarchical clustering and a combination of candidate genotypes and clinical variables, we identified several distinct clusters of patients at high risk (36-38%) and low risk (10-17%) of respiratory depression; the relative risk of respiratory depression for high versus low risk clusters was 2.1-3.8 (p = 0.003). Conclusion: Genetic risk predictions (genetic signatures) along with clinical risk factors effectively identify children at higher and lower risks of opioid-induced respiratory depression. Genetic signatures of respiratory depression offer strategies for improved clinical decision support to guide clinicians to balance the risks of opioid adverse effects with analgesia. Original submitted 9 July 2014; Revision submitted 19 September 2014.

18.
Chem Biol ; 21(12): 1618-28, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25455859

RESUMO

Ras GTPases regulate intracellular signaling involved in cell proliferation. Elevated Ras signaling activity has been associated with human cancers. Ras activation is catalyzed by guanine nucleotide exchange factors (GEFs), of which SOS1 is a major member that transduces receptor tyrosine kinase signaling to Ras. We have developed a rational approach coupling virtual screening with experimental screening in identifying small-molecule inhibitors targeting the catalytic site of SOS1 and SOS1-regulated Ras activity. A lead inhibitor, NSC-658497, was found to bind to SOS1, competitively suppress SOS1-Ras interaction, and dose-dependently inhibit SOS1 GEF activity. Mutagenesis and structure-activity relationship studies map the NSC-658497 site of action to the SOS1 catalytic site, and define the chemical moieties in the inhibitor essential for the activity. NSC-658497 showed dose-dependent efficacy in inhibiting Ras, downstream signaling activities, and associated cell proliferation. These studies establish a proof of principle for rational design of small-molecule inhibitors targeting Ras GEF enzymatic activity.


Assuntos
Desenho de Fármacos , Proteína SOS1/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Camundongos , Modelos Moleculares , Mutagênese , Proteína SOS1/química , Proteína SOS1/genética , Proteína SOS1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
19.
Int J Oncol ; 45(3): 978-84, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24913497

RESUMO

Lung cancer is the leading cause of cancer death worldwide. There is an urgent need for early diagnostic tools and novel therapies in order to increase lung cancer survival. Secretory phospholipase A2 group IIa (sPLA2-IIa) is involved in inflammation, tumorigenesis and metastasis. We were the first to uncover that cancer cells secrete sPLA2­IIa. sPLA2­IIa is overexpressed in almost all specimens of human lung cancers examined and is significantly elevated in the plasma of lung cancer patients. High levels of plasma sPLA2-IIa are significantly associated with advanced stage and decreased overall cancer survival. In this study, we further showed that elevated HER/HER2­PI3K-Akt-NF-κB signaling contributes to sPLA2-IIa overexpression in lung cancer cells. sPLA2-IIa in turn phosphorylates and activates HER2 and HER3 in a time- and dose­dependent manner in lung cancer cells. The structure and sequence­based docking analysis revealed that sPLA2-IIa ß hairpin shares structural similarity with the corresponding EGF hairpin. sPLA2-IIa forms an extensive interface with EGFR and brings the two lobes of EGFR into an active conformation. sPLA2-IIa also enhances the NF-κB promoter activity. Anti-sPLA2-IIa antibody, but not the small molecule sPLA2-IIa inhibitor LY315920, significantly inhibits sPLA2­IIa-induced activation of NF-κB promoter. Our findings support the notion that sPLA2-IIa functions as a ligand for the EGFR family of receptors leading to an elevated HER/HER2-elicited signaling. Plasma sPLA2-IIa can potentially serve as lung cancer biomarker and sPLA2­IIa is a potential therapeutic target against lung cancer.


Assuntos
Adenocarcinoma Bronquioloalveolar/metabolismo , Fosfolipases A2 do Grupo II/metabolismo , Neoplasias Pulmonares/metabolismo , Transdução de Sinais , Adenocarcinoma Bronquioloalveolar/patologia , Biomarcadores Tumorais/sangue , Linhagem Celular , Regulação Neoplásica da Expressão Gênica , Fosfolipases A2 do Grupo II/química , Humanos , Neoplasias Pulmonares/patologia , Simulação de Acoplamento Molecular , Neuregulina-1/metabolismo , Fosforilação , Regiões Promotoras Genéticas , Conformação Proteica , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Receptor ErbB-2/metabolismo , Quinase Induzida por NF-kappaB
20.
Methods Mol Biol ; 928: 1-16, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22956129

RESUMO

Small molecule docking and virtual screening of candidate compounds have become an integral part of drug discovery pipelines, complementing and streamlining experimental efforts in that regard. In this chapter, we describe specific software packages and protocols that can be used to efficiently set up a computational screening using a library of compounds and a docking program. We also discuss consensus- and clustering-based approaches that can be used to assess the results, and potentially re-rank the hits. While docking programs share many common features, they may require tailored implementation of virtual screening pipelines for specific computing platforms. Here, we primarily focus on solutions for several public domain packages that are widely used in the context of drug development.


Assuntos
Software , Simulação por Computador , Desenho de Fármacos , Descoberta de Drogas , Ligação Proteica
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