Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Mol Cell Biochem ; 476(1): 13-22, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32816187

RESUMO

Strategies to improve the early diagnosis of prostate cancer will provide opportunities for earlier intervention. The blood-based prostate-specific antigen (PSA) assay is widely used for prostate cancer diagnosis but specificity of the assay is not satisfactory. An algorithm based on serum levels of PSA combined with other serum biomarkers may significantly improve prostate cancer diagnosis. Plasma glycan-binding IgG/IgM studies suggested that glycan patterns differ between normal and tumor cells. We hypothesize that in prostate cancer glycoproteins or glycolipids are secreted from tumor tissues into the blood and induce auto-immunoglobulin (Ig) production. A 24-glycan microarray and a 5-glycan subarray were developed using plasma samples obtained from 35 prostate cancer patients and 54 healthy subjects to identify glycan-binding auto-IgGs. Neu5Acα2-8Neu5Acα2-8Neu5Acα (G81)-binding auto-IgG was higher in prostate cancer samples and, when levels of G81-binding auto-IgG and growth differentiation factor-15 (GDF-15 or NAG-1) were combined with levels of PSA, the prediction rate of prostate cancer increased from 78.2% to 86.2% than with PSA levels alone. The G81 glycan-binding auto-IgG fraction was isolated from plasma samples using G81 glycan-affinity chromatography and identified by N-terminal sequencing of the 50 kDa heavy chain variable region of the IgG. G81 glycan-binding 25 kDa fibroblast growth factor-1 (FGF1) fragment was also identified by N-terminal sequencing. Our results demonstrated that a multiplex diagnostic combining G81 glycan-binding auto-IgG, GDF-15/NAG-1 and PSA (≥ 2.1 ng PSA/ml for cancer) increased the specificity of prostate cancer diagnosis by 8%. The multiplex assessment could improve the early diagnosis of prostate cancer thereby allowing the prompt delivery of prostate cancer treatment.


Assuntos
Biomarcadores Tumorais/sangue , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Imunoglobulina G/sangue , Neoplasias da Próstata/sangue , Idoso , Algoritmos , Biomarcadores/sangue , Detecção Precoce de Câncer , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , Polímeros/química , Polissacarídeos/química , Antígeno Prostático Específico/sangue , Proteômica , Reprodutibilidade dos Testes
2.
Br J Cancer ; 121(10): 890-893, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31601961

RESUMO

Fetoplacental neuroblastoma metastasis has been postulated as a mechanism accounting for concordant cases where one twin develops a primary tumour and the second twin manifests the disease without an identifiable primary site. These tumours may originate and spread concomitantly due to the same genetic background shared by monozygotic twins. This study investigated the molecular profile of stage MS neuroblastoma presenting concomitantly in monozygotic twins. Comparative genomic hybridisation (aCGH) was done for each of the twin liver tumour and peripheral blood samples at diagnosis. Comparison of copy-number variation (CNV) regions revealed a set of CNVs that were common to both tumour specimens and not apparent in the blood. The CNV signature in both twins' tumours was highly similar, suggesting a common clonal origin. Additional findings included large deletion of chromosome 10 and amplification of chromosome 17. Notably, both liver samples had amplification of a short region involving DEIN (chromosome 4q34.1). Similar CNVs strongly support a common clonal origin and metastatic spread from one twin to the other. DEIN is a long-coding RNA (IncRNA) that has been found highly expressed in stage MS neuroblastoma and is likely involved in biological processes such as cell migration and metastasis.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Variações do Número de Cópias de DNA/genética , Neoplasias Hepáticas/genética , Neuroblastoma/genética , Neoplasias das Glândulas Suprarrenais/patologia , Deleção Cromossômica , Cromossomos Humanos Par 10/genética , Cromossomos Humanos Par 17/genética , Hibridização Genômica Comparativa , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Lactente , Neoplasias Hepáticas/patologia , Metástase Neoplásica , Neuroblastoma/patologia , RNA Longo não Codificante/genética , Gêmeos Monozigóticos/genética
3.
Inflamm Res ; 68(12): 993-998, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31511910

RESUMO

BACKGROUND: Neuroinflammation and toll-like receptors (TLR) of the innate immune system have been implicated in epilepsy. We previously reported high levels of microRNAs miR-142-3p and miR-223-3p in epileptogenic brain tissue resected for the treatment of intractable epilepsy in children with tuberous sclerosis complex (TSC). As miR-142-3p has recently been reported to be a ligand and activator of TLR7, a detector of exogenous and endogenous single-stranded RNA, we evaluated TLR7 expression and downstream IL23A activation in surgically resected TSC brain tissue. METHODS: Gene expression analysis was performed on cortical tissue obtained from surgery of TSC children with pharmacoresistent epilepsy. Expression of TLRs 2, 4 and 7 was measured using NanoString nCounter assays. Real-time quantitative PCR was used to confirm TLR7 expression and compare TLR7 activation, indicated by IL-23A levels, to levels of miR-142-3p. Protein markers characteristic for TLR7 activation were assessed using data from our existing quantitative proteomics dataset of TSC tissue. Capillary electrophoresis Western blots were used to confirm TLR7 protein expression in a subset of samples. RESULTS: TLR7 transcript expression was present in all TSC specimens. The signaling competent form of TLR7 protein was detected in the membrane fraction of each sample tested. Downstream activation of TLR7 was found in epileptogenic lesions having elevated neuroinflammation indicated by clinical neuroimaging. TLR7 activity was significantly associated with tissue levels of miR-142-3p. CONCLUSION: TLR7 activation by microRNAs may contribute to the neuroinflammatory cascade in epilepsy in TSC. Further characterization of this mechanism may enable the combined of use of neuroimaging and TLR7 inhibitors in a personalized approach towards the treatment of intractable epilepsy.


Assuntos
Epilepsia/genética , MicroRNAs/genética , Receptor 7 Toll-Like/genética , Esclerose Tuberosa/genética , Criança , Pré-Escolar , Feminino , Expressão Gênica , Humanos , Lactente , Masculino , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética
4.
Carcinogenesis ; 39(4): 556-561, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29471417

RESUMO

Prostate cancer is one of the most common cancers in men worldwide. Currently available diagnostic and prognostic tools for this disease, such as prostate specific antigen, suffer from lack of specificity and sensitivity, resulting in over- and misdiagnosis. Hence, there is an urgent need for clinically relevant biomarkers capable of distinguishing between aggressive and nonaggressive forms of prostate cancer to aid in stratification, management and therapeutic decisions. To address this unmet need, we investigated the patterns of expression of a panel of 68 plasma-derived microRNAs (miRNAs) in a cohort of African American (AA) and European American (EA) prostate cancer patients (n = 114). miRNA qPCR results were analyzed using in-depth statistical methods, and a bioinformatics analysis was conducted to identify potential targets of the differentially expressed miRNAs. Our data demonstrate that a new previously unreported circulating miRNA signature consisting of a combination of interacting miRNAs (miR-17/miR-192) and an independent miRNA (miR-181a) are capable of segregating aggressive and nonaggressive prostate cancer in both AA and EA patients. The interacting miRNAs outperformed independent miRNAs in identifying aggressiveness. Our results suggest that these circulating miRNAs may constitute novel biomarkers of prostate cancer aggressiveness in both races and warrant further investigation.


Assuntos
Biomarcadores Tumorais/sangue , MicroRNAs/sangue , Neoplasias da Próstata/sangue , Adulto , Idoso , Biomarcadores Tumorais/genética , MicroRNA Circulante/análise , MicroRNA Circulante/genética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia
5.
Neurobiol Dis ; 109(Pt A): 76-87, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28993242

RESUMO

Tuberous sclerosis complex (TSC) is characterized by hamartomatous lesions in various organs and arises due to mutations in the TSC1 or TSC2 genes. TSC mutations lead to a range of neurological manifestations including epilepsy, cognitive impairment, autism spectrum disorders (ASD), and brain lesions that include cortical tubers. There is evidence that seizures arise at or near cortical tubers, but it is unknown why some tubers are epileptogenic while others are not. We have previously reported increased tryptophan metabolism measured with α[11C]-methyl-l-tryptophan (AMT) positron emission tomography (PET) in epileptogenic tubers in approximately two-thirds of patients with tuberous sclerosis and intractable epilepsy. However, the underlying mechanisms leading to seizure onset in TSC remain poorly characterized. MicroRNAs are enriched in the brain and play important roles in neurodevelopment and brain function. Recent reports have shown aberrant microRNA expression in epilepsy and TSC. In this study, we performed microRNA expression profiling in brain specimens obtained from TSC patients undergoing epilepsy surgery for intractable epilepsy. Typically, in these resections several non-seizure onset tubers are resected together with the seizure-onset tubers because of their proximity. We directly compared seizure onset tubers, with and without increased tryptophan metabolism measured with PET, and non-onset tubers to assess the role of microRNAs in epileptogenesis associated with these lesions. Whether a particular tuber was epileptogenic or non-epileptogenic was determined with intracranial electrocorticography, and tryptophan metabolism was measured with AMT PET. We identified a set of five microRNAs (miR-142-3p, 142-5p, 223-3p, 200b-3p and 32-5p) that collectively distinguish among the three primary groups of tubers: non-onset/AMT-cold (NC), onset/AMT-cold (OC), and onset/AMT-hot (OH). These microRNAs were significantly upregulated in OH tubers compared to the other two groups, and microRNA expression was most significantly associated with AMT-PET uptake. The microRNAs target a group of genes enriched for synaptic signaling and epilepsy risk, including SLC12A5, SYT1, GRIN2A, GRIN2B, KCNB1, SCN2A, TSC1, and MEF2C. We confirmed the interaction between miR-32-5p and SLC12A5 using a luciferase reporter assay. Our findings provide a new avenue for subsequent mechanistic studies of tuber epileptogenesis in TSC.


Assuntos
MicroRNAs/metabolismo , Tomografia por Emissão de Pósitrons , Convulsões/metabolismo , Triptofano/metabolismo , Esclerose Tuberosa/diagnóstico por imagem , Esclerose Tuberosa/metabolismo , Criança , Pré-Escolar , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Lactente , Masculino , Convulsões/complicações , Convulsões/diagnóstico por imagem , Convulsões/genética , Simportadores/metabolismo , Triptofano/análogos & derivados , Triptofano/análise , Esclerose Tuberosa/complicações , Esclerose Tuberosa/genética
6.
Int J Mol Sci ; 19(10)2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241319

RESUMO

Intracellular signaling is controlled to a large extent by the phosphorylation status of proteins. To determine how human breast cells can be reprogrammed during tumorigenic progression, we profiled cell lines in the MCF10A lineage by phosphoproteomic analyses. A large cluster of proteins involved in RNA splicing were hypophosphorylated as cells progressed to a hyperplastic state, and then hyperphosphorylated after progression to a fully metastatic phenotype. A comprehensive transcriptomic approach was used to determine whether alterations in splicing factor phosphorylation status would be reflected in changes in mRNA splicing. Results indicated that the degree of mRNA splicing trended with the degree of tumorigenicity of the 4 cell lines tested. That is, highly metastatic cell cultures had the greatest number of genes with splice variants, and these genes had greater fluctuations in expression intensities. Genes with high splicing indices were mapped against gene ontology terms to determine whether they have known roles in cancer. This group showed highly significant associations for angiogenesis, cytokine-mediated signaling, cell migration, programmed cell death and epithelial cell differentiation. In summary, data from global profiling of a human model of breast cancer development suggest that therapeutics should be developed which target signaling pathways that regulate RNA splicing.


Assuntos
Processamento Alternativo , Neoplasias da Mama/patologia , Carcinogênese/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Comunicação Celular , Linhagem Celular Tumoral , Reprogramação Celular , Humanos , Fosforilação , Transdução de Sinais , Transcriptoma
7.
Cereb Cortex ; 26(3): 1059-71, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25452577

RESUMO

Tuberous sclerosis complex (TSC) is a multisystem genetic disorder caused by mutations in the TSC1 and TSC2 genes. Over 80% of TSC patients are affected by epilepsy, but the molecular events contributing to seizures in TSC are not well understood. Recent reports have demonstrated that the brain is enriched with microRNA activity, and they are critical in neural development and function. However, little is known about the role of microRNAs in TSC. Here, we report the characterization of aberrant microRNA activity in cortical tubers resected from 5 TSC patients surgically treated for medically intractable epilepsy. By comparing epileptogenic tubers with adjacent nontuber tissue, we identified a set of 4 coordinately overexpressed microRNAs (miRs 23a, 34a, 34b*, 532-5p). We used quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomic profiling to investigate the combined effect of the 4 microRNAs on target proteins. The proportion of repressed proteins among the predicted targets was significantly greater than in the overall proteome and was highly enriched for proteins involved in synaptic signal transmission. Among the combinatorial targets were TSC1, coding for the protein hamartin, and several epilepsy risk genes. We found decreased levels of hamartin in epileptogenic tubers and confirmed targeting of the TSC1 3' UTR by miRs-23a and 34a.


Assuntos
Encéfalo/metabolismo , Epilepsia Resistente a Medicamentos/genética , Epilepsia Resistente a Medicamentos/metabolismo , MicroRNAs/metabolismo , Esclerose Tuberosa/metabolismo , Encéfalo/cirurgia , Criança , Pré-Escolar , Cromatografia Líquida , Epilepsia Resistente a Medicamentos/epidemiologia , Epilepsia Resistente a Medicamentos/cirurgia , Feminino , Humanos , Masculino , Análise em Microsséries , NF-kappa B/metabolismo , Proteoma , Reação em Cadeia da Polimerase em Tempo Real , Risco , Sinapses/metabolismo , Espectrometria de Massas em Tandem , Esclerose Tuberosa/complicações , Esclerose Tuberosa/genética , Esclerose Tuberosa/cirurgia , Proteína 1 do Complexo Esclerose Tuberosa , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo
8.
J Pharmacol Exp Ther ; 358(2): 216-29, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27225895

RESUMO

Squalene synthase inhibitors (SSIs), such as squalestatin 1 (SQ1), reduce cholesterol biosynthesis but cause the accumulation of isoprenoids derived from farnesyl pyrophosphate (FPP), which can modulate the activity of nuclear receptors, including the constitutive androstane receptor (CAR), farnesoid X receptor, and peroxisome proliferator-activated receptors (PPARs). In comparison, 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (e.g., pravastatin) inhibit production of both cholesterol and nonsterol isoprenoids. To characterize the effects of isoprenoids on hepatocellular physiology, microarrays were used to compare orthologous gene expression from primary cultured mouse and rat hepatocytes that were treated with either SQ1 or pravastatin. Compared with controls, 47 orthologs were affected by both inhibitors, 90 were affected only by SQ1, and 51 were unique to pravastatin treatment (P < 0.05, ≥1.5-fold change). When the effects of SQ1 and pravastatin were compared directly, 162 orthologs were found to be differentially coregulated between the two treatments. Genes involved in cholesterol and unsaturated fatty acid biosynthesis were up-regulated by both inhibitors, consistent with cholesterol depletion; however, the extent of induction was greater in rat than in mouse hepatocytes. SQ1 induced several orthologs associated with microsomal, peroxisomal, and mitochondrial fatty acid oxidation and repressed orthologs involved in cell cycle regulation. By comparison, pravastatin repressed the expression of orthologs involved in retinol and xenobiotic metabolism. Several of the metabolic genes altered by isoprenoids were inducible by a PPARα agonist, whereas cytochrome P450 isoform 2B was inducible by activators of CAR. Our findings indicate that SSIs uniquely influence cellular lipid metabolism and cell cycle regulation, probably due to FPP catabolism through the farnesol pathway.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Colesterol/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Pravastatina/farmacologia , Terpenos/metabolismo , Ácidos Tricarboxílicos/farmacologia , Animais , Sinergismo Farmacológico , Feminino , Masculino , Camundongos , Ratos , Homologia de Sequência do Ácido Nucleico
9.
Mol Carcinog ; 55(11): 1867-1875, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27696538

RESUMO

Aberrant methylation of DNA is a common event in the development of cancers, including squamous cell carcinoma (SCC) of the human esophagus. In the present study, we determined: (a) whether aberrant DNA methylation also occurs in the development of N-nitrosomethylbenzylamine (NMBA)-induced tumorigenesis in the rat esophagus, a model of human esophageal SCC; and (b) if so, whether dietary black raspberries (BRBs) are capable of preventing this aberrant DNA methylation. A diet containing 5% BRBs inhibited the development of NMBA-induced tumors in the rat esophagus. This inhibition was associated with reduced mRNA levels of the DNA methyltransferases, Dnmt1 and Dnmt3b, in both dysplastic lesions and in papillomas of the esophagus. In addition, promoter methylation of Sfrp4, a WNT pathway antagonist, was significantly reduced by the berry diet, and this was associated with decreased nuclear localization of ß-CATENIN and reduced expression of c-MYC protein in NMBA-treated esophagi. Decreased promoter methylation of Sfrp4 correlated with decreased expression of Dmnt3b and, ultimately, with increased Sfrp4 mRNA expression. This suggests that epigenetic alterations in NMBA-induced rat esophageal tumorigenesis recapitulate epigenetic events in human esophageal SCC, and that BRBs could be useful in preventing the aberrant DNA methylation involved in the development of human esophageal SCC. © 2015 Wiley Periodicals, Inc.


Assuntos
Carcinoma de Células Escamosas/dietoterapia , DNA (Citosina-5-)-Metiltransferases/genética , Dimetilnitrosamina/análogos & derivados , Neoplasias Esofágicas/dietoterapia , Extratos Vegetais/administração & dosagem , Proteínas Proto-Oncogênicas/genética , Rubus/química , Animais , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/genética , DNA (Citosina-5-)-Metiltransferase 1 , Metilação de DNA/efeitos dos fármacos , Dimetilnitrosamina/efeitos adversos , Epigênese Genética/efeitos dos fármacos , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Extratos Vegetais/farmacologia , Ratos , Via de Sinalização Wnt/efeitos dos fármacos , DNA Metiltransferase 3B
11.
Drug Metab Dispos ; 43(7): 1061-70, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25948711

RESUMO

During cholestasis, the bile acid-conjugating enzymes, SULT2A1 and UGT2B4, work in concert to prevent the accumulation of toxic bile acids. To understand the impact of sulfotransferase deficiency on human hepatic gene expression, we knocked down 3'-phosphoadenosine-5'-phosphosulfate synthases (PAPSS) 1 and 2, which catalyze synthesis of the obligate sulfotransferase cofactor, in HepG2 cells. PAPSS knockdown caused no change in SULT2A1 expression; however, UGT2B4 expression increased markedly (∼41-fold increase in UGT2B4 mRNA content). Knockdown of SULT2A1 in HepG2 cells also increased UGT2B4 expression. To investigate the underlying mechanism, we transfected PAPSS-deficient HepG2 cells with a luciferase reporter plasmid containing ∼2 Kb of the UGT2B4 5'-flanking region, which included a response element for the bile acid-sensing nuclear receptor, farnesoid X receptor (FXR). FXR activation or overexpression increased UGT2B4 promoter activity; however, knocking down FXR or mutating or deleting the FXR response element did not significantly decrease UGT2B4 promoter activity. Further evaluation of the UGT2B4 5'-flanking region indicated the presence of distal regulatory elements between nucleotides -10090 and -10037 that negatively and positively regulated UGT2B4 transcription. Pulse-chase analysis showed that increased UGT2B4 expression in PAPSS-deficient cells was attributable to both increased mRNA synthesis and stability. Transfection analysis demonstrated that the UGT2B4 3'-untranslated region decreased luciferase reporter expression less in PAPSS-deficient cells than in control cells. These data indicate that knocking down PAPSS increases UGT2B4 transcription and mRNA stability as a compensatory response to the loss of SULT2A1 activity, presumably to maintain bile acid-conjugating activity.


Assuntos
Ácidos e Sais Biliares/genética , Ácidos e Sais Biliares/metabolismo , Glucuronosiltransferase/biossíntese , Glucuronosiltransferase/genética , Complexos Multienzimáticos/genética , Sulfato Adenililtransferase/genética , Região 5'-Flanqueadora/genética , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Mutagênese Sítio-Dirigida , Mutação/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Citoplasmáticos e Nucleares/genética , Sulfotransferases/biossíntese , Sulfotransferases/genética , Transfecção , Regulação para Cima/genética
12.
J Proteome Res ; 13(2): 496-505, 2014 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-24224561

RESUMO

Environmental exposure to mercury is suggested to contribute to human immune dysfunction. To shed light on the mechanism, we identified changes in the phosphoproteomic profile of the WEHI-231 B cell line after intoxication with Hg(2+). These changes were compared to changes in the phosphoproteome that were induced by pervanadate or okadaic acid exposure. Both 250 µM HgCl2 and pervanadate, a known phosphotyrosine phosphatase inhibitor, caused an increase in the number of proteins identified after TiO2 affinity selection and LC-MS/MS analysis. Pervanadate treatment had a larger effect than Hg(2+) on the number of Scansite motifs that were tyrosine-phosphorylated, 17, and Ingenuity canonical signaling pathways activated, 4, with score >5.0. However, Hg(2+) had a more focused effect, primarily causing tyrosine-phosphorylation in src homology 2 domains in proteins that are in the B cell receptor signaling pathway. The finding that many of the changes induced by Hg(2+) overlap with those of pervanadate, indicates that at high concentrations Hg(2+) inhibits protein tyrosine phosphatases.


Assuntos
Linfócitos B/efeitos dos fármacos , Proteínas Sanguíneas/metabolismo , Mercúrio/farmacologia , Linfócitos B/metabolismo , Linhagem Celular , Cromatografia de Afinidade , Humanos , Fosforilação , Espectrometria de Massas em Tandem
13.
Toxicol Appl Pharmacol ; 276(1): 47-54, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24440445

RESUMO

Network and protein-protein interaction analyses of proteins undergoing Hg²âº-induced phosphorylation and dephosphorylation in Hg²âº-intoxicated mouse WEHI-231 B cells identified Lyn as the most interconnected node. Lyn is a Src family protein tyrosine kinase known to be intimately involved in the B cell receptor (BCR) signaling pathway. Under normal signaling conditions the tyrosine kinase activity of Lyn is controlled by phosphorylation, primarily of two well known canonical regulatory tyrosine sites, Y-397 and Y-508. However, Lyn has several tyrosine residues that have not yet been determined to play a major role under normal signaling conditions, but are potentially important sites for phosphorylation following mercury exposure. In order to determine how Hg²âº exposure modulates the phosphorylation of additional residues in Lyn, a targeted MS assay was developed. Initial mass spectrometric surveys of purified Lyn identified 7 phosphorylated tyrosine residues. A quantitative assay was developed from these results using the multiple reaction monitoring (MRM) strategy. WEHI-231 cells were treated with Hg²âº, pervanadate (a phosphatase inhibitor), or anti-Ig antibody (to stimulate the BCR). Results from these studies showed that the phosphoproteomic profile of Lyn after exposure of the WEHI-231 cells to a low concentration of Hg²âº closely resembled that of anti-Ig antibody stimulation, whereas exposure to higher concentrations of Hg²âº led to increases in the phosphorylation of Y-193/Y-194, Y-501 and Y-508 residues. These data indicate that mercury can disrupt a key regulatory signal transduction pathway in B cells and point to phospho-Lyn as a potential biomarker for mercury exposure.


Assuntos
Linfócitos B/efeitos dos fármacos , Mercúrio/toxicidade , Transdução de Sinais/efeitos dos fármacos , Quinases da Família src/metabolismo , Animais , Doenças Autoimunes/induzido quimicamente , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores/metabolismo , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Intoxicação por Mercúrio/enzimologia , Intoxicação por Mercúrio/imunologia , Intoxicação por Mercúrio/metabolismo , Camundongos , Concentração Osmolar , Fragmentos de Peptídeos/agonistas , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Tirosina Fosfatases/farmacologia , Receptores de Antígenos de Linfócitos B/agonistas , Receptores de Antígenos de Linfócitos B/metabolismo , Espectrometria de Massas em Tandem , Tirosina/metabolismo , Vanadatos/farmacologia , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/química
14.
Hear Res ; 447: 109022, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705005

RESUMO

The disruption of ribbon synapses in the cochlea impairs the transmission of auditory signals from the cochlear sensory receptor cells to the auditory cortex. Although cisplatin-induced loss of ribbon synapses is well-documented, and studies have reported nitration of cochlear proteins after cisplatin treatment, yet the underlying mechanism of cochlear synaptopathy is not fully understood. This study tests the hypothesis that cisplatin treatment alters the abundance of cochlear synaptosomal proteins, and selective targeting of nitrative stress prevents the associated synaptic dysfunction. Auditory brainstem responses of mice treated with cisplatin showed a reduction in amplitude and an increase in latency of wave I, indicating cisplatin-induced synaptic dysfunction. The mass spectrometry analysis of cochlear synaptosomal proteins identified 102 proteins that decreased in abundance and 249 that increased in abundance after cisplatin treatment. Pathway analysis suggested that the dysregulated proteins were involved in calcium binding, calcium ion regulation, synapses, and endocytosis pathways. Inhibition of nitrative stress by co-treatment with MnTBAP, a peroxynitrite scavenger, attenuated cisplatin-induced changes in the abundance of 27 proteins. Furthermore, MnTBAP co-treatment prevented the cisplatin-induced decrease in the amplitude and increase in the latency of wave I. Together, these findings suggest a potential role of oxidative/nitrative stress in cisplatin-induced cochlear synaptic dysfunction.


Assuntos
Cisplatino , Cóclea , Potenciais Evocados Auditivos do Tronco Encefálico , Proteômica , Sinapses , Sinaptossomos , Cisplatino/toxicidade , Cisplatino/farmacologia , Animais , Cóclea/efeitos dos fármacos , Cóclea/metabolismo , Cóclea/patologia , Cóclea/fisiopatologia , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Sinapses/patologia , Sinaptossomos/metabolismo , Sinaptossomos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Camundongos Endogâmicos CBA , Masculino , Ototoxicidade/metabolismo , Ototoxicidade/fisiopatologia , Camundongos
15.
BMC Bioinformatics ; 14: 346, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24289175

RESUMO

BACKGROUND: Disulfide engineering is an important biotechnological tool that has advanced a wide range of research. The introduction of novel disulfide bonds into proteins has been used extensively to improve protein stability, modify functional characteristics, and to assist in the study of protein dynamics. Successful use of this technology is greatly enhanced by software that can predict pairs of residues that will likely form a disulfide bond if mutated to cysteines. RESULTS: We had previously developed and distributed software for this purpose: Disulfide by Design (DbD). The original DbD program has been widely used; however, it has a number of limitations including a Windows platform dependency. Here, we introduce Disulfide by Design 2.0 (DbD2), a web-based, platform-independent application that significantly extends functionality, visualization, and analysis capabilities beyond the original program. Among the enhancements to the software is the ability to analyze the B-factor of protein regions involved in predicted disulfide bonds. Importantly, this feature facilitates the identification of potential disulfides that are not only likely to form but are also expected to provide improved thermal stability to the protein. CONCLUSIONS: DbD2 provides platform-independent access and significantly extends the original functionality of DbD. A web server hosting DbD2 is provided at http://cptweb.cpt.wayne.edu/DbD2/.


Assuntos
Dissulfetos/química , Internet , Engenharia de Proteínas/métodos , Proteínas/química , Software , Biologia Computacional/métodos , Proteínas/genética , Proteínas/metabolismo
16.
Drug Metab Dispos ; 41(10): 1769-77, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23920219

RESUMO

Several microRNAs (miRNAs) were selected for characterization of their response to insulin signaling based on in silico predictions of targeting CYP2E1 mRNA and previous reports implicating their role in hepatic metabolism and disease. CYP2E1 expression decreases with increasing insulin concentration and has been shown to be regulated by the phosphatidylinositol 3-kinase (PI3-K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. In primary cultured rat hepatocytes, insulin at 0.1, 1.0, and 10 nM elevated miRNA-132 and -212 expression ∼2- and 1.8-fold, respectively, whereas expression of miRNA-181a and -122 increased ∼1.6- and 1.4-fold, respectively. In contrast, insulin failed to alter significantly the expression of miRNA let-7a. Mechanistic studies using inhibitors of PI3-K, Akt, and mTOR were used to examine the role of the insulin signaling pathway on miR expression and resulted in significant suppression of the insulin-mediated elevation of miR-132, miR-212, and miR-122 levels, with a lesser effect observed for miR-181a. Targeting of the rat CYP2E1 3'-untranslated region (UTR) by miR-132 and -212 was demonstrated with an in vitro luciferase reporter assay. These data show that insulin, which regulates CYP2E1 through the PI3-K, Akt, mTOR signaling pathway, also regulates the expression of miRs that target the 3'-UTR of CYP 2E1 mRNA and are involved in the regulation of hepatic metabolism and disease.


Assuntos
Citocromo P-450 CYP2E1/genética , Hepatócitos/metabolismo , Insulina/genética , MicroRNAs/genética , Fosfatidilinositol 3-Quinase/genética , Proteínas Proto-Oncogênicas c-akt/genética , Serina-Treonina Quinases TOR/genética , Regiões 3' não Traduzidas/genética , Animais , Células COS , Células Cultivadas , Chlorocebus aethiops , Citocromo P-450 CYP2E1/metabolismo , Insulina/metabolismo , MicroRNAs/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , Ratos , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismo
17.
Pediatr Pulmonol ; 58(7): 1982-1992, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37098830

RESUMO

BACKGROUND AND OBJECTIVES: Bronchopulmonary dysplasia (BPD) is a serious complication of preterm birth, resulting in significant morbidity and mortality. Recent studies have suggested that microRNA (miRNA) dysregulation is involved in the pathogenesis of BPD and may serve as biomarkers for early detection. We conducted a directed search for dysregulated miRNAs in lung and heart autopsy samples of infants with histologic BPD. METHODS: We used archived lung and heart samples from BPD (13 lung, 6 heart) and control (24 lung, 5 heart) subjects. To measure miRNA expression, RNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tissue specimens then reverse-transcribed, labeled, and hybridized to miRNA microarrays. The microarrays were scanned, and data were quantile normalized. Statistical analysis with a moderated t-test and control of the false discovery rate (5%) was used to compare normalized miRNA expression values between clinical categories. RESULTS: With our set of 48 samples, 43 miRNAs had a significant difference in expression comparing BPD to non-BPD controls. Among the most statistically significant miRNAs, miR-378b, miRNA-184, miRNA-3667-5p, miRNA-3976, miRNA-4646-5p, and miRNA-7846-3p were all consistently upregulated in both the heart and lung tissues of BPD subjects. The cellular pathway predicted to be most affected by these miRNAs is the Hippo signaling pathway. CONCLUSIONS: This study identifies miRNAs that are similarly dysregulated in postmortem lung and heart samples in subjects with histologic BPD. These miRNAs may contribute to the pathogenesis of BPD, have potential as biomarkers, and may provide insight to novel approaches for diagnosis and treatment.


Assuntos
Displasia Broncopulmonar , MicroRNAs , Nascimento Prematuro , Feminino , Humanos , Recém-Nascido , Lactente , MicroRNAs/genética , MicroRNAs/metabolismo , Displasia Broncopulmonar/genética , Displasia Broncopulmonar/metabolismo , Pulmão/metabolismo , Biomarcadores/metabolismo
18.
BMC Bioinformatics ; 13: 84, 2012 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-22568790

RESUMO

BACKGROUND: The rabbit is an important model organism used in a wide range of biomedical research. However, the rabbit genome is still sparsely annotated, thus prohibiting extensive functional analysis of gene sets derived from whole-genome experiments. We developed a web-based application that provides augmented annotation and orthologue analysis for rabbit genes. Importantly, the application allows comprehensive functional analysis through the use of orthologous relationships. RESULTS: Using data extracted from several public bioinformatics repositories we created Better Bunny, a database and query tool that extensively augments the available functional annotation for rabbit genes. Using the complete set of target genes from a commercial rabbit gene expression microarray as our benchmark, we are able to obtain functional information for 88 % of the genes on the microarray. Previously, functional information was available for fewer than 10 % of the rabbit genes. CONCLUSIONS: We have developed a freely available, web-accessible bioinformatics tool that enables investigators to quickly and easily perform extensive functional analysis of rabbit genes (http://cptweb.cpt.wayne.edu). The software application fills a critical void for a wide range of biomedical research that relies on the rabbit model and requires characterization of biological function for large sets of genes.


Assuntos
Bases de Dados Genéticas , Anotação de Sequência Molecular/métodos , Coelhos/genética , Software , Animais , Biologia Computacional , Genoma , Internet , Análise em Microsséries , Interface Usuário-Computador
19.
Biochem Pharmacol ; 205: 115283, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36208684

RESUMO

Despite the recently approved new therapies, the clinical outcomes of acute myeloid leukemia (AML) patients remain disappointing, highlighting the need for novel therapies. Our lab has previously demonstrated the promising outlook for CUDC-907, a dual inhibitor of PI3K and HDAC, in combination with venetoclax (VEN), against AML both in vitro and in vivo at least partially through suppression of c-Myc. In this study, we further elucidated the mechanism of action of the combination in preclinical models of AML. We demonstrated that the combination significantly reduced primary AML cell engraftment in immunocompromised mice. RNA sequencing and metabolomics analyses revealed that the combination reduced the levels for mRNAs of key TCA cycle genes and metabolites in the TCA cycle, respectively. This was accompanied by a reduced oxygen consumption rate (OCR), demonstrating that the combination suppressed oxidative phosphorylation (OXPHOS). Metabolomics analyses revealed that a large number of metabolites upregulated in AraC-resistant AML cells could be downregulated by the combination. CUDC-907 synergized with VEN in inducing apoptosis in the AraC-resistant AML cells. In conclusion, the CUDC-907 and VEN combination induces metabolic and transcriptomic reprograming and suppression of OXPHOS in AML, which provides additional mechanisms underlying the synergy between the two agents.


Assuntos
Leucemia Mieloide Aguda , Fosfatidilinositol 3-Quinases , Camundongos , Animais , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Citarabina , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Mitocôndrias/metabolismo , Apoptose
20.
J Biol Chem ; 285(25): 19246-58, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20404327

RESUMO

Aging and DNA polymerase beta deficiency (beta-pol(+/-)) interact to accelerate the development of malignant lymphomas and adenocarcinoma and increase tumor bearing load in mice. Folate deficiency (FD) has been shown to induce DNA damage repaired via the base excision repair (BER) pathway. We anticipated that FD and BER deficiency would interact to accelerate aberrant crypt foci (ACF) formation and tumor development in beta-pol haploinsufficient animals. FD resulted in a significant increase in ACF formation in wild type (WT) animals exposed to 1,2-dimethylhydrazine, a known colon and liver carcinogen; however, FD reduced development of ACF in beta-pol haploinsufficient mice. Prolonged feeding of the FD diet resulted in advanced ACF formation and liver tumors in wild type mice. However, FD attenuated onset and progression of ACF and prevented liver tumorigenesis in beta-pol haploinsufficient mice, i.e. FD provided protection against tumorigenesis in a BER-deficient environment in all tissues where 1,2-dimethylhydrazine exerts its damage. Here we show a distinct down-regulation in DNA repair pathways, e.g. BER, nucleotide excision repair, and mismatch repair, and decline in cell proliferation, as well as an up-regulation in poly(ADP-ribose) polymerase, proapoptotic genes, and apoptosis in colons of FD beta-pol haploinsufficient mice.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/prevenção & controle , DNA Polimerase beta/genética , Deficiência de Ácido Fólico/metabolismo , 1,2-Dimetilidrazina/farmacologia , Ração Animal , Animais , Apoptose , Dano ao DNA , Reparo do DNA , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Vitaminas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA