41 results on '"Nogueira TC"'
Search Results
2. A robust human norovirus replication model in zebrafish larvae.
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Van Dycke J, Ny A, Conceição-Neto N, Maes J, Hosmillo M, Cuvry A, Goodfellow I, Nogueira TC, Verbeken E, Matthijnssens J, de Witte P, Neyts J, and Rocha-Pereira J
- Subjects
- Animals, Antiviral Agents administration & dosage, Caliciviridae Infections virology, Foodborne Diseases virology, Gastroenteritis virology, Host Microbial Interactions, Humans, Larva virology, Metagenomics, Models, Animal, Norovirus genetics, Virus Cultivation methods, Virus Replication drug effects, Norovirus pathogenicity, Norovirus physiology, Virus Replication physiology, Zebrafish virology
- Abstract
Human noroviruses (HuNoVs) are the most common cause of foodborne illness, with a societal cost of $60 billion and 219,000 deaths/year. The lack of robust small animal models has significantly hindered the understanding of norovirus biology and the development of effective therapeutics. Here we report that HuNoV GI and GII replicate to high titers in zebrafish (Danio rerio) larvae; replication peaks at day 2 post infection and is detectable for at least 6 days. The virus (HuNoV GII.4) could be passaged from larva to larva two consecutive times. HuNoV is detected in cells of the hematopoietic lineage and the intestine, supporting the notion of a dual tropism. Antiviral treatment reduces HuNoV replication by >2 log10, showing that this model is suited for antiviral studies. Zebrafish larvae constitute a simple and robust replication model that will largely facilitate studies of HuNoV biology and the development of antiviral strategies., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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3. Molecular genetics of the transcription factor GLIS3 identifies its dual function in beta cells and neurons.
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Calderari S, Ria M, Gérard C, Nogueira TC, Villate O, Collins SC, Neil H, Gervasi N, Hue C, Suarez-Zamorano N, Prado C, Cnop M, Bihoreau MT, Kaisaki PJ, Cazier JB, Julier C, Lathrop M, Werner M, Eizirik DL, and Gauguier D
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- Animals, Autophagy, Binding Sites, Cell Line, Tumor, Cells, Cultured, Diabetes Mellitus, Experimental genetics, Diabetes Mellitus, Experimental metabolism, Hippocampus cytology, Male, Neurogenesis, Neurons cytology, PC12 Cells, Polymorphism, Genetic, Protein Binding, Rats, Rats, Sprague-Dawley, Transcription Factors chemistry, Transcription Factors genetics, Insulin-Secreting Cells metabolism, Neurons metabolism, Transcription Factors metabolism
- Abstract
The GLIS family zinc finger 3 isoform (GLIS3) is a risk gene for Type 1 and Type 2 diabetes, glaucoma and Alzheimer's disease endophenotype. We identified GLIS3 binding sites in insulin secreting cells (INS1) (FDR q<0.05; enrichment range 1.40-9.11 fold) sharing the motif wrGTTCCCArTAGs, which were enriched in genes involved in neuronal function and autophagy and in risk genes for metabolic and neuro-behavioural diseases. We confirmed experimentally Glis3-mediated regulation of the expression of genes involved in autophagy and neuron function in INS1 and neuronal PC12 cells. Naturally-occurring coding polymorphisms in Glis3 in the Goto-Kakizaki rat model of type 2 diabetes were associated with increased insulin production in vitro and in vivo, suggestive alteration of autophagy in PC12 and INS1 and abnormal neurogenesis in hippocampus neurons. Our results support biological pleiotropy of GLIS3 in pathologies affecting β-cells and neurons and underline the existence of trans‑nosology pathways in diabetes and its co-morbidities., (Copyright © 2017 Elsevier Inc. All rights reserved.)
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- 2018
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4. Neuron-enriched RNA-binding Proteins Regulate Pancreatic Beta Cell Function and Survival.
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Juan-Mateu J, Rech TH, Villate O, Lizarraga-Mollinedo E, Wendt A, Turatsinze JV, Brondani LA, Nardelli TR, Nogueira TC, Esguerra JLS, Alvelos MI, Marchetti P, Eliasson L, and Eizirik DL
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- Alternative Splicing, Animals, Apoptosis, Cell Line, Cell Survival, Cells, Cultured, ELAV-Like Protein 4 genetics, ELAV-Like Protein 4 metabolism, Gene Expression Regulation, Glucose metabolism, Humans, Insulin metabolism, Insulin-Secreting Cells metabolism, RNA Splicing Factors genetics, RNA Splicing Factors metabolism, RNA-Binding Proteins genetics, Rats, Insulin-Secreting Cells cytology, RNA-Binding Proteins metabolism
- Abstract
Pancreatic beta cell failure is the central event leading to diabetes. Beta cells share many phenotypic traits with neurons, and proper beta cell function relies on the activation of several neuron-like transcription programs. Regulation of gene expression by alternative splicing plays a pivotal role in brain, where it affects neuronal development, function, and disease. The role of alternative splicing in beta cells remains unclear, but recent data indicate that splicing alterations modulated by both inflammation and susceptibility genes for diabetes contribute to beta cell dysfunction and death. Here we used RNA sequencing to compare the expression of splicing-regulatory RNA-binding proteins in human islets, brain, and other human tissues, and we identified a cluster of splicing regulators that are expressed in both beta cells and brain. Four of them, namely Elavl4, Nova2, Rbox1, and Rbfox2, were selected for subsequent functional studies in insulin-producing rat INS-1E, human EndoC-βH1 cells, and in primary rat beta cells. Silencing of Elavl4 and Nova2 increased beta cell apoptosis, whereas silencing of Rbfox1 and Rbfox2 increased insulin content and secretion. Interestingly, Rbfox1 silencing modulates the splicing of the actin-remodeling protein gelsolin, increasing gelsolin expression and leading to faster glucose-induced actin depolymerization and increased insulin release. Taken together, these findings indicate that beta cells share common splicing regulators and programs with neurons. These splicing regulators play key roles in insulin release and beta cell survival, and their dysfunction may contribute to the loss of functional beta cell mass in diabetes., (© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.)
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- 2017
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5. N'-[(1E)-(5-Nitro-furan-2-yl)methyl-idene]thio-phene-2-carbohydrazide: crystal structure and Hirshfeld surface analysis.
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Cardoso LN, Nogueira TC, Wardell JL, Wardell SM, de Souza MV, Jotani MM, and Tiekink ER
- Abstract
In the title carbohydrazide, C10H7N3O4S, the dihedral angle between the terminal five-membered rings is 27.4 (2)°, with these lying to the same side of the plane through the central CN2C(=O) atoms (r.m.s. deviation = 0.0403 Å), leading to a curved mol-ecule. The conformation about the C=N imine bond [1.281 (5) Å] is E, and the carbonyl O and amide H atoms are anti. In the crystal, N-H⋯O hydrogen bonds lead to supra-molecular chains, generated by a 41 screw-axis along the c direction. A three-dimensional architecture is consolidated by thienyl-C-H⋯O(nitro) and furanyl-C-H⋯O(nitro) inter-actions, as well as π-π inter-actions between the thienyl and furanyl rings [inter-centroid distance = 3.515 (2) Å]. These, and other, weak inter-molecular inter-actions, e.g. nitro-N-O⋯π(thien-yl), have been investigated by Hirshfeld surface analysis, which confirms the dominance of the conventional N-H⋯O hydrogen bonding to the overall mol-ecular packing.
- Published
- 2016
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6. Resistance to the nucleotide analogue cidofovir in HPV(+) cells: a multifactorial process involving UMP/CMP kinase 1.
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Topalis D, Nogueira TC, De Schutter T, El Amri C, Krečmerová M, Naesens L, Balzarini J, Andrei G, and Snoeck R
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- ATP-Binding Cassette Transporters biosynthesis, Cell Line, Tumor, Cidofovir, Cytidine Triphosphate biosynthesis, Cytosine pharmacology, Female, HeLa Cells, Humans, Microbial Sensitivity Tests, Nucleoside-Phosphate Kinase biosynthesis, Papillomaviridae, Phosphorylation, Solute Carrier Proteins biosynthesis, Uridine Triphosphate biosynthesis, Uterine Cervical Neoplasms pathology, Cytosine analogs & derivatives, Drug Resistance, Neoplasm genetics, Nucleoside-Phosphate Kinase metabolism, Organophosphonates pharmacology, Papillomavirus Infections drug therapy, Uterine Cervical Neoplasms drug therapy, Uterine Cervical Neoplasms virology
- Abstract
Human papillomavirus (HPV) is responsible for cervical cancer, and its role in head and neck carcinoma has been reported. No drug is approved for the treatment of HPV-related diseases but cidofovir (CDV) exhibits selective antiproliferative activity. In this study, we analyzed the effects of CDV-resistance (CDVR) in two HPV(+) (SiHaCDV and HeLaCDV) and one HPV(-) (HaCaTCDV) tumor cell lines. Quantification of CDV metabolites and analysis of the sensitivity profile to chemotherapeutics was performed. Transporters expression related to multidrug-resistance (MRP2, P-gp, BCRP) was also investigated. Alterations of CDV metabolism in SiHaCDV and HeLaCDV, but not in HaCaTCDV, emerged via impairment of UMP/CMPK1 activity. Mutations (P64T and R134M) as well as down-regulation of UMP/CMPK1 expression were observed in SiHaCDV and HeLaCDV, respectively. Altered transporters expression in SiHaCDV and/or HeLaCDV, but not in HaCaTCDV, was also noted. Taken together, these results indicate that CDVR in HPV(+) tumor cells is a multifactorial process.
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- 2016
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7. Quinoxaline Nucleus: A Promising Scaffold in Anti-cancer Drug Discovery.
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Pinheiro AC, Mendonça Nogueira TC, and de Souza MV
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- Antineoplastic Agents chemical synthesis, Chemistry Techniques, Synthetic, Drug Discovery, Humans, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Quinoxalines chemistry
- Abstract
Heterocyclic compounds are a class of substances, which play a critical role in modern drug discovery being incorporated in the structure of a large variety of drugs used in many different types of diseases. Quinoxaline is an important heterocyclic nucleus with a wide spectrum of biological activities, and recently much attention has been found on anticancer drug discovery based on this class. Owing to the importance of this system, the aim of this review is to provide an update on the synthesis and anticancer activity of quinoxaline derivatives covering articles published between 2010 and 2015.
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- 2016
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8. Mast cells infiltrate pancreatic islets in human type 1 diabetes.
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Martino L, Masini M, Bugliani M, Marselli L, Suleiman M, Boggi U, Nogueira TC, Filipponi F, Occhipinti M, Campani D, Dotta F, Syed F, Eizirik DL, Marchetti P, and De Tata V
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- Adult, Aged, Cell Survival, Female, Humans, Male, Middle Aged, Young Adult, Diabetes Mellitus, Type 1 pathology, Islets of Langerhans pathology, Mast Cells pathology, Pancreas pathology
- Abstract
Aims/hypothesis: Beta cell destruction in human type 1 diabetes occurs through the interplay of genetic and environmental factors, and is mediated by immune cell infiltration of pancreatic islets. In this study, we explored the role of mast cells as an additional agent in the pathogenesis of type 1 diabetes insulitis., Methods: Pancreatic tissue from donors without diabetes and with type 1 and 2 diabetes was studied using different microscopy techniques to identify islet-infiltrating cells. The direct effects of histamine exposure on isolated human islets and INS-1E cells were assessed using cell-survival studies and molecular mechanisms., Results: A larger number of mast cells were found to infiltrate pancreatic islets in samples from donors with type 1 diabetes, compared with those from donors without diabetes or with type 2 diabetes. Evidence of mast cell degranulation was observed, and the extent of the infiltration correlated with beta cell damage. Histamine, an amine that is found at high levels in mast cells, directly contributed to beta cell death in isolated human islets and INS-1E cells via a caspase-independent pathway., Conclusions/interpretation: These findings suggest that mast cells might be responsible, at least in part, for immune-mediated beta cell alterations in human type 1 diabetes. If this is the case, inhibition of mast cell activation and degranulation might act to protect beta cells in individuals with type 1 diabetes.
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- 2015
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9. Weak C-H···O and C-H···π hydrogen bonds and π-π stacking interactions in a series of four N'-[(E)-(aryl)methylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazides.
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Nogueira TC, Pinheiro AC, Wardell JL, de Souza MV, Abberley JP, and Harrison WT
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- Crystallography, X-Ray, Hydrogen Bonding, Molecular Structure, Benzylidene Compounds chemistry, Hydrazines chemistry, Oxazoles chemistry
- Abstract
Oxazolidin-2-ones are widely used as protective groups for 1,2-amino alcohols and chiral derivatives are employed as chiral auxiliaries. The crystal structures of four differently substituted oxazolidinecarbohydrazides, namely N'-[(E)-benzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12N3O3, (I), N'-[(E)-2-chlorobenzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12ClN3O3, (II), (4S)-N'-[(E)-4-chlorobenzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12ClN3O3, (III), and (4S)-N'-[(E)-2,6-dichlorobenzylidene]-N,3-dimethyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C13H13Cl2N3O3, (IV), show that an unexpected mild-condition racemization from the chiral starting materials has occurred in (I) and (II). In the extended structures, the centrosymmetric phases, which each crystallize with two molecules (A and B) in the asymmetric unit, form A+B dimers linked by pairs of N-H···O hydrogen bonds, albeit with different O-atom acceptors. One dimer is composed of one molecule with an S configuration for its stereogenic centre and the other with an R configuration, and possesses approximate local inversion symmetry. The other dimer consists of either R,R or S,S pairs and possesses approximate local twofold symmetry. In the chiral structure, N-H···O hydrogen bonds link the molecules into C(5) chains, with adjacent molecules related by a 21 screw axis. A wide variety of weak interactions, including C-H···O, C-H···Cl, C-H···π and π-π stacking interactions, occur in these structures, but there is little conformity between them.
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- 2015
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10. Human Exportin-1 is a Target for Combined Therapy of HIV and AIDS Related Lymphoma.
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Boons E, Vanstreels E, Jacquemyn M, Nogueira TC, Neggers JE, Vercruysse T, van den Oord J, Tamir S, Shacham S, Landesman Y, Snoeck R, Pannecouque C, Andrei G, and Daelemans D
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- Acrylates chemistry, Acrylates pharmacology, Acrylates therapeutic use, Active Transport, Cell Nucleus drug effects, Animals, Apoptosis drug effects, Base Sequence, CRISPR-Cas Systems genetics, Cell Cycle Checkpoints drug effects, Cell Line, Cell Nucleus drug effects, Cell Nucleus metabolism, Female, HIV isolation & purification, Humans, Karyopherins metabolism, Mice, Nude, Molecular Sequence Data, NF-kappa B metabolism, Protein Binding drug effects, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Viral metabolism, Receptors, Cytoplasmic and Nuclear metabolism, Reproducibility of Results, Triazoles chemistry, Triazoles pharmacology, Triazoles therapeutic use, Tumor Suppressor Protein p53 metabolism, Virus Replication drug effects, Xenograft Model Antitumor Assays, rev Gene Products, Human Immunodeficiency Virus genetics, rev Gene Products, Human Immunodeficiency Virus metabolism, Exportin 1 Protein, HIV drug effects, Karyopherins antagonists & inhibitors, Lymphoma, AIDS-Related drug therapy, Molecular Targeted Therapy, Receptors, Cytoplasmic and Nuclear antagonists & inhibitors
- Abstract
Infection with HIV ultimately leads to advanced immunodeficiency resulting in an increased incidence of cancer. For example primary effusion lymphoma (PEL) is an aggressive non-Hodgkin lymphoma with very poor prognosis that typically affects HIV infected individuals in advanced stages of immunodeficiency. Here we report on the dual anti-HIV and anti-PEL effect of targeting a single process common in both diseases. Inhibition of the exportin-1 (XPO1) mediated nuclear transport by clinical stage orally bioavailable small molecule inhibitors (SINE) prevented the nuclear export of the late intron-containing HIV RNA species and consequently potently suppressed viral replication. In contrast, in CRISPR-Cas9 genome edited cells expressing mutant C528S XPO1, viral replication was unaffected upon treatment, clearly demonstrating the anti-XPO1 mechanism of action. At the same time, SINE caused the nuclear accumulation of p53 tumor suppressor protein as well as inhibition of NF-κB activity in PEL cells resulting in cell cycle arrest and effective apoptosis induction. In vivo, oral administration arrested PEL tumor growth in engrafted mice. Our findings provide strong rationale for inhibiting XPO1 as an innovative strategy for the combined anti-retroviral and anti-neoplastic treatment of HIV and PEL and offer perspectives for the treatment of other AIDS-associated cancers and potentially other virus-related malignancies.
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- 2015
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11. Selective regulation of hepatic lipid metabolism by the AMP-activated protein kinase pathway in late-pregnant rats.
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Rodrigues SC, Pantaleão LC, Nogueira TC, Gomes PR, Albuquerque GG, Nachbar RT, Torres-Leal FL, Caperuto LC, Lellis-Santos C, Anhê GF, and Bordin S
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- AMP-Activated Protein Kinases genetics, Aminoimidazole Carboxamide analogs & derivatives, Aminoimidazole Carboxamide pharmacology, Animals, Female, Gene Expression Regulation physiology, Gluconeogenesis drug effects, Gluconeogenesis physiology, Glycogen chemistry, Glycogen metabolism, Malate Dehydrogenase genetics, Malate Dehydrogenase metabolism, Pregnancy, Rats, Rats, Wistar, Ribonucleotides pharmacology, Triglycerides metabolism, AMP-Activated Protein Kinases metabolism, Lipid Metabolism physiology, Liver metabolism, Signal Transduction physiology
- Abstract
The liver plays an essential role in maternal metabolic adaptation during late pregnancy. With regard to lipid metabolism, increased secretion of very low-density lipoprotein (VLDL) is characteristic of late pregnancy. Despite this well-described metabolic plasticity, the molecular changes underlying the hepatic adaptation to pregnancy remain unclear. As AMPK is a key intracellular energy sensor, we investigated whether this protein assumes a causal role in the hepatic adaptation to pregnancy. Pregnant Wistar rats were treated with vehicle or AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) for 5 days starting at gestational day 14. At the end of treatment, the rats were subjected to an intraperitoneal pyruvate tolerance test and in situ liver perfusion with pyruvate. The livers were processed for Western blot analysis, quantitative PCR, thin-layer chromatography, enzymatic activity, and glycogen content measurements. Blood biochemical profiles were also assessed. We found that AMPK and ACC phosphorylation were reduced in the livers of pregnant rats in parallel with a reduced level of hepatic gluconeogenesis of pyruvate. This effect was accompanied by both a reduction in the levels of hepatic triglycerides (TG) and an increase in circulating levels of TG. Treatment with AICAR restored hepatic levels of TG to those observed in nonpregnant rats. Additionally, AMPK activation reduced the upregulation of genes related to VLDL synthesis and secretion observed in the livers of pregnant rats. We conclude that the increased secretion of hepatic TG in late pregnancy is concurrent with a transcriptional profile that favors VLDL production. This transcriptional profile results from the reduction in hepatic AMPK activity., (Copyright © 2014 the American Physiological Society.)
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- 2014
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12. Nova1 is a master regulator of alternative splicing in pancreatic beta cells.
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Villate O, Turatsinze JV, Mascali LG, Grieco FA, Nogueira TC, Cunha DA, Nardelli TR, Sammeth M, Salunkhe VA, Esguerra JL, Eliasson L, Marselli L, Marchetti P, and Eizirik DL
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- Animals, Apoptosis, Calcium metabolism, Cytokines pharmacology, Forkhead Box Protein O3, Forkhead Transcription Factors metabolism, Gene Expression Profiling, Gene Knockdown Techniques, Humans, Insulin metabolism, Nerve Tissue Proteins metabolism, Neuro-Oncological Ventral Antigen, RNA-Binding Proteins antagonists & inhibitors, RNA-Binding Proteins genetics, Rats, Wistar, Receptor, Insulin genetics, Receptor, Insulin metabolism, Alternative Splicing, Insulin-Secreting Cells metabolism, RNA-Binding Proteins physiology
- Abstract
Alternative splicing (AS) is a fundamental mechanism for the regulation of gene expression. It affects more than 90% of human genes but its role in the regulation of pancreatic beta cells, the producers of insulin, remains unknown. Our recently published data indicated that the 'neuron-specific' Nova1 splicing factor is expressed in pancreatic beta cells. We have presently coupled specific knockdown (KD) of Nova1 with RNA-sequencing to determine all splice variants and downstream pathways regulated by this protein in beta cells. Nova1 KD altered the splicing of nearly 5000 transcripts. Pathway analysis indicated that these genes are involved in exocytosis, apoptosis, insulin receptor signaling, splicing and transcription. In line with these findings, Nova1 silencing inhibited insulin secretion and induced apoptosis basally and after cytokine treatment in rodent and human beta cells. These observations identify a novel layer of regulation of beta cell function, namely AS controlled by key splicing regulators such as Nova1., (© The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.)
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- 2014
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13. Design, synthesis and biological evaluation of (E)-2-(2-arylhydrazinyl)quinoxalines, a promising and potent new class of anticancer agents.
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Rodrigues FA, Bomfim Ida S, Cavalcanti BC, Pessoa Cdo Ó, Wardell JL, Wardell SM, Pinheiro AC, Kaiser CR, Nogueira TC, Low JN, Gomes LR, and de Souza MV
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- Antineoplastic Agents chemistry, Cell Line, Tumor, Cell Proliferation drug effects, Coordination Complexes chemistry, Doxorubicin chemistry, Doxorubicin pharmacology, Humans, Hydrogen Bonding, Inhibitory Concentration 50, Iron chemistry, Ligands, Quinoxalines chemistry, Structure-Activity Relationship, Antineoplastic Agents chemical synthesis, Antineoplastic Agents pharmacology, Drug Design, Quinoxalines chemical synthesis, Quinoxalines pharmacology
- Abstract
A series of forty-seven quinoxaline derivatives, 2-(XYZC6H2CHN-NH)-quinoxalines, 1, have been synthesized and evaluated for their activity against four cancer cell lines: potent cytotoxicities were found (IC50 ranging from 0.316 to 15.749 μM). The structure-activity relationship (SAR) analysis indicated that the number, the positions and the type of substituents attached to the aromatic ring are critical for biological activity. The activities do not depend on the electronic effects of the substituents nor on the lypophilicities of the molecules. A common feature of active compounds is an ortho-hydroxy group in the phenyl ring. A potential role of these ortho-hydroxy derivatives is as N,N,O-tridentate ligands complexing with a vital metal, such as iron, and thereby preventing proliferation of cells. The most active compound was (1: X,Y=2,3-(OH)2, Z=H), which displayed a potent cytotoxicity comparable to that of the reference drug doxorubicin., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
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- 2014
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14. GLIS3, a susceptibility gene for type 1 and type 2 diabetes, modulates pancreatic beta cell apoptosis via regulation of a splice variant of the BH3-only protein Bim.
- Author
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Nogueira TC, Paula FM, Villate O, Colli ML, Moura RF, Cunha DA, Marselli L, Marchetti P, Cnop M, Julier C, and Eizirik DL
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- Aged, Alternative Splicing genetics, Animals, Apoptosis Regulatory Proteins metabolism, Bcl-2-Like Protein 11, DNA-Binding Proteins, Diabetes Mellitus, Type 1 etiology, Diabetes Mellitus, Type 2 etiology, Female, Gene Knockdown Techniques, Humans, Insulin genetics, Insulin-Secreting Cells metabolism, Insulin-Secreting Cells pathology, Male, Membrane Proteins metabolism, Mice, Middle Aged, Protein Isoforms genetics, Proto-Oncogene Proteins metabolism, Rats, Repressor Proteins, Trans-Activators, Apoptosis genetics, Apoptosis Regulatory Proteins genetics, Diabetes Mellitus, Type 1 genetics, Diabetes Mellitus, Type 2 genetics, Membrane Proteins genetics, Proto-Oncogene Proteins genetics, Transcription Factors genetics
- Abstract
Mutations in human Gli-similar (GLIS) 3 protein cause neonatal diabetes. The GLIS3 gene region has also been identified as a susceptibility risk locus for both type 1 and type 2 diabetes. GLIS3 plays a role in the generation of pancreatic beta cells and in insulin gene expression, but there is no information on the role of this gene on beta cell viability and/or susceptibility to immune- and metabolic-induced stress. GLIS3 knockdown (KD) in INS-1E cells, primary FACS-purified rat beta cells, and human islet cells decreased expression of MafA, Ins2, and Glut2 and inhibited glucose oxidation and insulin secretion, confirming the role of this transcription factor for the beta cell differentiated phenotype. GLIS3 KD increased beta cell apoptosis basally and sensitized the cells to death induced by pro-inflammatory cytokines (interleukin 1β + interferon-γ) or palmitate, agents that may contribute to beta cell loss in respectively type 1 and 2 diabetes. The increased cell death was due to activation of the intrinsic (mitochondrial) pathway of apoptosis, as indicated by cytochrome c release to the cytosol, Bax translocation to the mitochondria and activation of caspases 9 and 3. Analysis of the pathways implicated in beta cell apoptosis following GLIS3 KD indicated modulation of alternative splicing of the pro-apoptotic BH3-only protein Bim, favouring expression of the pro-death variant BimS via inhibition of the splicing factor SRp55. KD of Bim abrogated the pro-apoptotic effect of GLIS3 loss of function alone or in combination with cytokines or palmitate. The present data suggest that altered expression of the candidate gene GLIS3 may contribute to both type 1 and 2 type diabetes by favouring beta cell apoptosis. This is mediated by alternative splicing of the pro-apoptotic protein Bim and exacerbated formation of the most pro-apoptotic variant BimS., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2013
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15. C/EBP homologous protein contributes to cytokine-induced pro-inflammatory responses and apoptosis in β-cells.
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Allagnat F, Fukaya M, Nogueira TC, Delaroche D, Welsh N, Marselli L, Marchetti P, Haefliger JA, Eizirik DL, and Cardozo AK
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- Animals, Caspase 3 metabolism, Caspase 9 metabolism, Cell Line, Cell Nucleus metabolism, Diabetes Mellitus, Type 1 metabolism, Diabetes Mellitus, Type 1 pathology, Endoplasmic Reticulum Stress, I-kappa B Kinase metabolism, Insulin-Secreting Cells cytology, Interferon-gamma pharmacology, Interleukin-1beta pharmacology, Mitochondria metabolism, Myeloid Cell Leukemia Sequence 1 Protein, NF-kappa B metabolism, Proto-Oncogene Proteins c-bcl-2 metabolism, Rats, Transcription Factor CHOP antagonists & inhibitors, Transcription Factor CHOP genetics, Transcription Factor RelA metabolism, Tumor Necrosis Factor-alpha pharmacology, Apoptosis drug effects, Cytokines pharmacology, Insulin-Secreting Cells metabolism, Transcription Factor CHOP metabolism
- Abstract
Induction of the C/EBP homologous protein (CHOP) is considered a key event for endoplasmic reticulum (ER) stress-mediated apoptosis. Type 1 diabetes (T1D) is characterized by an autoimmune destruction of the pancreatic β-cells. Pro-inflammatory cytokines are early mediators of β-cell death in T1D. Cytokines induce ER stress and CHOP overexpression in β-cells, but the role for CHOP overexpression in cytokine-induced β-cell apoptosis remains controversial. We presently observed that CHOP knockdown (KD) prevents cytokine-mediated degradation of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and myeloid cell leukemia sequence 1 (Mcl-1), thereby decreasing the cleavage of executioner caspases 9 and 3, and apoptosis. Nuclear factor-κB (NF-κB) is a crucial transcription factor regulating β-cell apoptosis and inflammation. CHOP KD resulted in reduced cytokine-induced NF-κB activity and expression of key NF-κB target genes involved in apoptosis and inflammation, including iNOS, FAS, IRF-7, IL-15, CCL5 and CXCL10. This was due to decreased IκB degradation and p65 translocation to the nucleus. The present data suggest that CHOP has a dual role in promoting β-cell death: (1) CHOP directly contributes to cytokine-induced β-cell apoptosis by promoting cytokine-induced mitochondrial pathways of apoptosis; and (2) by supporting the NF-κB activation and subsequent cytokine/chemokine expression, CHOP may contribute to apoptosis and the chemo attraction of mononuclear cells to the islets during insulitis.
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- 2012
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16. The regulation of Rasd1 expression by glucocorticoids and prolactin controls peripartum maternal insulin secretion.
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Lellis-Santos C, Sakamoto LH, Bromati CR, Nogueira TC, Leite AR, Yamanaka TS, Kinote A, Anhê GF, and Bordin S
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- Animals, Blotting, Western, Cell Line, Chromatin Immunoprecipitation, Corticosterone metabolism, Dexamethasone pharmacology, Female, Immunoprecipitation, Insulin Secretion, Islets of Langerhans drug effects, Polymerase Chain Reaction, Rats, Rats, Wistar, STAT5 Transcription Factor genetics, STAT5 Transcription Factor metabolism, Signal Transduction drug effects, Transcortin genetics, Transcortin metabolism, ras Proteins genetics, Insulin metabolism, Islets of Langerhans metabolism, Peripartum Period metabolism, Prolactin pharmacology, ras Proteins metabolism
- Abstract
The transition from gestation to lactation is characterized by a robust adaptation of maternal pancreatic β-cells. Consistent with the loss of β-cell mass, glucose-induced insulin secretion is down-regulated in the islets of early lactating dams. Extensive experimental evidence has demonstrated that the surge of prolactin is responsible for the morphofunctional remodeling of the maternal endocrine pancreas during pregnancy, but the precise molecular mechanisms by which this phenotype is rapidly reversed after delivery are not completely understood. This study investigated whether glucocorticoid-regulated expression of Rasd1/Dexras, a small inhibitory G protein, is involved in this physiological plasticity. Immunofluorescent staining demonstrated that Rasd1 is localized within pancreatic β-cells. Rasd1 expression in insulin-secreting cells was increased by dexamethasone and decreased by prolactin. In vivo data confirmed that Rasd1 expression is decreased in islets from pregnant rats and increased in islets from lactating mothers. Knockdown of Rasd1 abolished the inhibitory effects of dexamethasone on insulin secretion and the protein kinase A, protein kinase C, and ERK1/2 pathways. Chromatin immunoprecipitation experiments revealed that glucocorticoid receptor (GR) and signal transducer and activator of transcription 5b (STAT5b) cooperatively mediate glucocorticoid-induced Rasd1 expression in islets. Prolactin inhibited the stimulatory effect of GR/STAT5b complex on Rasd1 transcription. Overall, our data indicate that the stimulation of Rasd1 expression by glucocorticoid at the end of pregnancy reverses the increased insulin secretion that occurs during pregnancy. Prolactin negatively regulates this pathway by inhibiting GR/STAT5b transcriptional activity on the Rasd1 gene.
- Published
- 2012
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17. Dermoscopy findings in tinea capitis: case report and literature review.
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Pinheiro AM, Lobato LA, and Varella TC
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- Black People, Child, Female, Humans, Tinea Capitis microbiology, Trichophyton isolation & purification, Dermoscopy, Tinea Capitis diagnosis
- Abstract
Dermoscopy is a method of increasing importance in the diagnoses of cutaneous diseases. On the scalp, dermoscopic aspects have been described in psoriasis, lichen planus, seborrheic dermatitis and discoid lupus. We describe the "comma" and "corkscrew hair" dermoscopic aspects found in a child of skin type 4, with tinea capitis.
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- 2012
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18. The transcription factor C/EBP delta has anti-apoptotic and anti-inflammatory roles in pancreatic beta cells.
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Moore F, Santin I, Nogueira TC, Gurzov EN, Marselli L, Marchetti P, and Eizirik DL
- Subjects
- Animals, Cell Line, Cytokines biosynthesis, Humans, Inflammation, Insulin-Secreting Cells drug effects, Insulinoma, Interferon Regulatory Factor-1, Rats, STAT1 Transcription Factor, Apoptosis, CCAAT-Enhancer-Binding Protein-delta physiology, Insulin-Secreting Cells pathology
- Abstract
In the course of Type 1 diabetes pro-inflammatory cytokines (e.g., IL-1β, IFN-γ and TNF-α) produced by islet-infiltrating immune cells modify expression of key gene networks in β-cells, leading to local inflammation and β-cell apoptosis. Most known cytokine-induced transcription factors have pro-apoptotic effects, and little is known regarding "protective" transcription factors. To this end, we presently evaluated the role of the transcription factor CCAAT/enhancer binding protein delta (C/EBPδ) on β-cell apoptosis and production of inflammatory mediators in the rat insulinoma INS-1E cells, in purified primary rat β-cells and in human islets. C/EBPδ is expressed and up-regulated in response to the cytokines IL-1β and IFN-γ in rat β-cells and human islets. Small interfering RNA-mediated C/EBPδ silencing exacerbated IL-1β+IFN-γ-induced caspase 9 and 3 cleavage and apoptosis in these cells. C/EBPδ deficiency increased the up-regulation of the transcription factor CHOP in response to cytokines, enhancing expression of the pro-apoptotic Bcl-2 family member BIM. Interfering with C/EBPδ and CHOP or C/EBPδ and BIM in double knockdown approaches abrogated the exacerbating effects of C/EBPδ deficiency on cytokine-induced β-cell apoptosis, while C/EBPδ overexpression inhibited BIM expression and partially protected β-cells against IL-1β+IFN-γ-induced apoptosis. Furthermore, C/EBPδ silencing boosted cytokine-induced production of the chemokines CXCL1, 9, 10 and CCL20 in β-cells by hampering IRF-1 up-regulation and increasing STAT1 activation in response to cytokines. These observations identify a novel function of C/EBPδ as a modulatory transcription factor that inhibits the pro-apoptotic and pro-inflammatory gene networks activated by cytokines in pancreatic β-cells.
- Published
- 2012
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19. Synthesis and antitubercular activity of new L-serinyl hydrazone derivatives.
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Pinheiro AC, Kaiser CR, Nogueira TC, Carvalho SA, da Silva EF, Feitosa Lde O, Henriques Md, Candéa AL, Lourenço MC, and de Souza MV
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- Antitubercular Agents chemical synthesis, Antitubercular Agents chemistry, Cell Survival drug effects, Cycloserine chemistry, Cycloserine pharmacology, Dose-Response Relationship, Drug, Hydrazones chemical synthesis, Hydrazones chemistry, Macrophages drug effects, Macrophages microbiology, Microbial Sensitivity Tests, Models, Molecular, Molecular Structure, Mycobacterium bovis isolation & purification, Mycobacterium tuberculosis cytology, Serine chemical synthesis, Serine chemistry, Stereoisomerism, Structure-Activity Relationship, Antitubercular Agents pharmacology, Hydrazones pharmacology, Mycobacterium tuberculosis drug effects, Serine pharmacology
- Abstract
A series of 32 L-serinyl hydrazone derivatives have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv, being also evaluated their cell viabilities in non infected and infected macrophages with Mycobacterium bovis Bacillus Calmette-Guerin (BCG). The compounds 8c, 8e, 8h and 8i, were non-cytotoxic and exhibited an important minimum inhibitory concentration (MIC) activity between 25 and 100 μg/mL, which can be compared with that of the tuberculostatic drug D-cicloserine (5-20 μg/mL).
- Published
- 2011
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20. Synthesis, cytotoxicity, and in vitro antileishmanial activity of mono-t-butyloxycarbonyl-protected diamines.
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Pinheiro AC, Rocha MN, Nogueira PM, Nogueira TC, Jasmim LF, de Souza MV, and Soares RP
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- Animals, Antiprotozoal Agents toxicity, Cell Line, Tumor, Diamines toxicity, Hep G2 Cells, Humans, Inhibitory Concentration 50, Lethal Dose 50, Macrophages drug effects, Macrophages parasitology, Mice, Mice, Inbred BALB C, Antiprotozoal Agents chemical synthesis, Antiprotozoal Agents pharmacology, Diamines chemical synthesis, Diamines pharmacology, Leishmania drug effects
- Abstract
Leishmania amazonensis is the etiologic agent of the cutaneous and diffuse leishmaniasis. This species is often associated with drug resistance, and the conventional treatments exhibit high toxicity for patients. Therefore, the search for new antileishmanial compounds is urgently needed since there is no vaccine available. In this study, using the in vitro traditional drug screening test, we have analyzed the effects of a series of diaminoalkanes monoprotected with t-butyloxycarbonyl (BOC) against L. amazonensis. Among the 18 tested compounds, 6 exhibited antileishmanial activity (2, 7-9, 17, and 18). Best IC(50) values (10.39 ± 0.27 and 3.8 ± 0.42 μg/mL) were observed for compounds 17 and 18 (H(2)N(CH(2))nNHBoc, n = 10 and 12), respectively. Although those compounds had higher lipophilicity as indicated by their cLog P values, compound 17 was very toxic. Determination of the selective indexes indicated that 50% of the active compounds were very toxic for HepG2 cells. However, compounds 2, 8, and 18 had good lipophilicity and were less toxic among all polyamine derivatives tested. The chemical properties of antileishmanial diamine derivatives, such as lipophilicity and cytotoxicity, are relevant factors for the design of new drugs. A higher lipophilicity is likely to improve the chances of reaching this intracellular parasite., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
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21. Early-stage retinal melatonin synthesis impairment in streptozotocin-induced diabetic wistar rats.
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do Carmo Buonfiglio D, Peliciari-Garcia RA, do Amaral FG, Peres R, Nogueira TC, Afeche SC, and Cipolla-Neto J
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- ARNTL Transcription Factors genetics, Animals, Arylalkylamine N-Acetyltransferase metabolism, Cell Survival, Chromatography, High Pressure Liquid, Circadian Rhythm physiology, Cyclic AMP metabolism, DNA Fragmentation, Enzyme-Linked Immunosorbent Assay, Gene Expression, Male, Pineal Gland surgery, Polymerase Chain Reaction, Radiometry, Rats, Rats, Wistar, Diabetes Mellitus, Experimental metabolism, Diabetic Retinopathy metabolism, Melatonin biosynthesis, Retina metabolism
- Abstract
Purpose: Retinal melatonin synthesis occurs in the photoreceptor layer in a circadian manner, controlling several physiologic rhythmic phenomena, besides being the most powerful natural free radical scavenger. The purpose of the present work was to evaluate the diurnal profile of retinal melatonin content and the regulation of its synthesis in the retina of streptozotocin-induced diabetic rats., Methods: Diabetes was induced in male Wistar rats (12 hour-12 hour light/dark cycle) with streptozotocin. Control, diabetic, and insulin-treated diabetic animals were killed every 3 hours throughout the light-dark cycle. Retinal melatonin content was measured by high-performance liquid chromatography, arylalkylamine N-acetyltransferase (AANAT) activity was analyzed by radiometric assay, Bmal1 gene expression was determined by qPCR, and cyclic adenosine monophosphate (cAMP) content was assessed by ELISA., Results: Control animals showed a clear retinal melatonin and AANAT activity daily rhythm, with high levels in the dark. Diabetic rats had both parameters reduced, and the impairment was prevented by immediate insulin treatment. In addition, the Bmal1 expression profile was lost in the diabetic group, and the retinal cAMP level was reduced 6 hours after lights on and 3 hours after lights off., Conclusions: The present work shows a melatonin synthesis reduction in diabetic rats retinas associated with a reduction in AANAT activity that was prevented by insulin treatment. The Bmal1-flattened gene expression and the cAMP reduction seem to be responsible for the AANAT activity decrease in diabetic animals. The melatonin synthesis reduction observed in the pineal gland of diabetic rats is also observed in a local melatonin tissue synthesizer, the retina.
- Published
- 2011
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22. Exposure to the viral by-product dsRNA or Coxsackievirus B5 triggers pancreatic beta cell apoptosis via a Bim / Mcl-1 imbalance.
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Colli ML, Nogueira TC, Allagnat F, Cunha DA, Gurzov EN, Cardozo AK, Roivainen M, Op de Beeck A, and Eizirik DL
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- Animals, Bcl-2-Like Protein 11, Cell Line, Cell Survival, Coxsackievirus Infections pathology, Diabetes Mellitus, Type 1 etiology, Diabetes Mellitus, Type 1 metabolism, Diabetes Mellitus, Type 1 pathology, Diabetes Mellitus, Type 1 virology, Eukaryotic Initiation Factor-2 metabolism, Humans, Insulin-Secreting Cells pathology, Insulin-Secreting Cells virology, Male, Mitochondria metabolism, Myeloid Cell Leukemia Sequence 1 Protein, Phosphorylation, Rats, Rats, Wistar, Apoptosis, Apoptosis Regulatory Proteins metabolism, Coxsackievirus Infections metabolism, Enterovirus B, Human metabolism, Insulin-Secreting Cells metabolism, Membrane Proteins metabolism, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-bcl-2 metabolism, RNA, Double-Stranded metabolism, RNA, Viral metabolism
- Abstract
The rise in type 1 diabetes (T1D) incidence in recent decades is probably related to modifications in environmental factors. Viruses are among the putative environmental triggers of T1D. The mechanisms regulating beta cell responses to viruses, however, remain to be defined. We have presently clarified the signaling pathways leading to beta cell apoptosis following exposure to the viral mimetic double-stranded RNA (dsRNA) and a diabetogenic enterovirus (Coxsackievirus B5). Internal dsRNA induces cell death via the intrinsic mitochondrial pathway. In this process, activation of the dsRNA-dependent protein kinase (PKR) promotes eIF2α phosphorylation and protein synthesis inhibition, leading to downregulation of the antiapoptotic Bcl-2 protein myeloid cell leukemia sequence 1 (Mcl-1). Mcl-1 decrease results in the release of the BH3-only protein Bim, which activates the mitochondrial pathway of apoptosis. Indeed, Bim knockdown prevented both dsRNA- and Coxsackievirus B5-induced beta cell death, and counteracted the proapoptotic effects of Mcl-1 silencing. These observations indicate that the balance between Mcl-1 and Bim is a key factor regulating beta cell survival during diabetogenic viral infections.
- Published
- 2011
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23. Absence of melatonin induces night-time hepatic insulin resistance and increased gluconeogenesis due to stimulation of nocturnal unfolded protein response.
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Nogueira TC, Lellis-Santos C, Jesus DS, Taneda M, Rodrigues SC, Amaral FG, Lopes AM, Cipolla-Neto J, Bordin S, and Anhê GF
- Subjects
- Adiposity drug effects, Animals, Body Weight drug effects, Circadian Rhythm, Eating drug effects, Immunoblotting, Insulin Resistance physiology, Oncogene Protein v-akt metabolism, Phenylbutyrates pharmacology, Phosphorylation drug effects, Pineal Gland physiology, Pineal Gland surgery, Rats, Rats, Wistar, Reverse Transcriptase Polymerase Chain Reaction, Gluconeogenesis drug effects, Liver drug effects, Liver metabolism, Melatonin pharmacology, Unfolded Protein Response drug effects
- Abstract
It is known that the circadian rhythm in hepatic phosphoenolpyruvate carboxykinase expression (a limiting catalytic step of gluconeogenesis) and hepatic glucose production is maintained by both daily oscillation in autonomic inputs to the liver and night feeding behavior. However, increased glycemia and reduced melatonin (Mel) levels have been recently shown to coexist in diabetic patients at the end of the night period. In parallel, pinealectomy (PINX) is known to cause glucose intolerance with increased basal glycemia exclusively at the end of the night. The mechanisms that underlie this metabolic feature are not completely understood. Here, we demonstrate that PINX rats show night-time hepatic insulin resistance characterized by reduced insulin-stimulated RAC-α serine/threonine-protein kinase phosphorylation and increased phosphoenolpyruvate carboxykinase expression. In addition, PINX rats display increased conversion of pyruvate into glucose at the end of the night. The regulatory mechanism suggests the participation of unfolded protein response (UPR), because PINX induces night-time increase in activating transcription factor 6 expression and prompts a circadian fashion of immunoglobulin heavy chain-binding protein, activating transcription factor 4, and CCAAT/enhancer-binding protein-homologous protein expression with Zenith values at the dark period. PINX also caused a night-time increase in Tribble 3 and regulatory-associated protein of mammalian target of rapamycin; both were reduced in liver of PINX rats treated with Mel. Treatment of PINX rats with 4-phenyl butyric acid, an inhibitor of UPR, restored night-time hepatic insulin sensitivity and abrogated gluconeogenesis in PINX rats. Altogether, the present data show that a circadian oscillation of UPR occurs in the liver due to the absence of Mel. The nocturnal UPR activation is related with night-time hepatic insulin resistance and increased gluconeogenesis in PINX rats.
- Published
- 2011
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24. UPR induces transient burst of apoptosis in islets of early lactating rats through reduced AKT phosphorylation via ATF4/CHOP stimulation of TRB3 expression.
- Author
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Bromati CR, Lellis-Santos C, Yamanaka TS, Nogueira TC, Leonelli M, Caperuto LC, Gorjão R, Leite AR, Anhê GF, and Bordin S
- Subjects
- Animals, Cells, Cultured, Female, Insulin metabolism, Islets of Langerhans cytology, Models, Animal, Phosphorylation physiology, Prolactin metabolism, Protein Serine-Threonine Kinases antagonists & inhibitors, Rats, Rats, Wistar, Signal Transduction, Transcription Factor CHOP metabolism, Activating Transcription Factor 4 metabolism, Apoptosis physiology, Islets of Langerhans metabolism, Lactation physiology, Protein Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism, Unfolded Protein Response physiology
- Abstract
Endocrine pancreas from pregnant rats undergoes several adaptations that comprise increase in β-cell number, mass and insulin secretion, and reduction of apoptosis. Lactogens are the main hormones that account for these changes. Maternal pancreas, however, returns to a nonpregnant state just after the delivery. The precise mechanism by which this reversal occurs is not settled but, in spite of high lactogen levels, a transient increase in apoptosis was already reported as early as the 3rd day of lactation (L3). Our results revealed that maternal islets displayed a transient increase in DNA fragmentation at L3, in parallel with decreased RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation (pAKT), a known prosurvival kinase. Wortmannin completely abolished the prosurvival action of prolactin (PRL) in cultured islets. Decreased pAKT in L3-islets correlated with increased Tribble 3 (TRB3) expression, a pseudokinase inhibitor of AKT. PERK and eIF2α phosphorylation transiently increased in islets from rats at the first day after delivery, followed by an increase in immunoglobulin heavy chain-binding protein (BiP), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) in islets from L3 rats. Chromatin immunoprecipitation (ChIP) and Re-ChIP experiments further confirmed increased binding of the heterodimer ATF4/CHOP to the TRB3 promoter in L3 islets. Treatment with PBA, a chemical chaperone that inhibits UPR, restored pAKT levels and inhibited the increase in apoptosis found in L3. Moreover, PBA reduced CHOP and TRB3 levels in β-cell from L3 rats. Altogether, our study collects compelling evidence that UPR underlies the physiological and transient increase in β-cell apoptosis after delivery. The UPR is likely to counteract prosurvival actions of PRL by reducing pAKT through ATF4/CHOP-induced TRB3 expression.
- Published
- 2011
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25. MKP-1 mediates glucocorticoid-induced ERK1/2 dephosphorylation and reduction in pancreatic ß-cell proliferation in islets from early lactating mothers.
- Author
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Nicoletti-Carvalho JE, Lellis-Santos C, Yamanaka TS, Nogueira TC, Caperuto LC, Leite AR, Anhê GF, and Bordin S
- Subjects
- Analysis of Variance, Animals, Blotting, Western, Cells, Cultured, Chromatin Immunoprecipitation, Dose-Response Relationship, Drug, Female, Glucocorticoids pharmacology, Insulin-Secreting Cells drug effects, Islets of Langerhans drug effects, Pregnancy, Rats, Cell Proliferation drug effects, Dexamethasone pharmacology, Dual Specificity Phosphatase 1 metabolism, Extracellular Signal-Regulated MAP Kinases metabolism, Insulin-Secreting Cells metabolism, Islets of Langerhans metabolism, Lactation metabolism, Phosphorylation drug effects
- Abstract
Maternal pancreatic islets undergo a robust increase of mass and proliferation during pregnancy, which allows a compensation of gestational insulin resistance. Studies have described that this adaptation switches to a low proliferative status after the delivery. The mechanisms underlying this reversal are unknown, but the action of glucocorticoids (GCs) is believed to play an important role because GCs counteract the pregnancy-like effects of PRL on isolated pancreatic islets maintained in cell culture. Here, we demonstrate that ERK1/2 phosphorylation (phospho-ERK1/2) is increased in maternal rat islets isolated on the 19th day of pregnancy. Phospho-ERK1/2 status on the 3rd day after delivery (L3) rapidly turns to values lower than that found in virgin control rats (CTL). MKP-1, a protein phosphatase able to dephosphorylate ERK1/2, is increased in islets from L3 rats. Chromatin immunoprecipitation assay revealed that binding of glucocorticoid receptor (GR) to MKP-1 promoter is also increased in islets from L3 rats. In addition, dexamethasone (DEX) reduced phospho-ERK1/2 and increased MKP-1 expression in RINm5F and MIN-6 cells. Inhibition of transduction with cycloheximide and inhibition of phosphatases with orthovanadate efficiently blocked DEX-induced downregulation of phospho-ERK1/2. In addition, specific knockdown of MKP-1 with siRNA suppressed the downregulation of phospho-ERK1/2 and the reduction of proliferation induced by DEX. Altogether, our results indicate that downregulation of phospho-ERK1/2 is associated with reduction in proliferation found in islets of early lactating mothers. This mechanism is probably mediated by GC-induced MKP-1 expression.
- Published
- 2010
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26. UPR-mediated TRIB3 expression correlates with reduced AKT phosphorylation and inability of interleukin 6 to overcome palmitate-induced apoptosis in RINm5F cells.
- Author
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Nicoletti-Carvalho JE, Nogueira TC, Gorjão R, Bromati CR, Yamanaka TS, Boschero AC, Velloso LA, Curi R, Anhê GF, and Bordin S
- Subjects
- Animals, Blotting, Western, Caspase 3 metabolism, Cell Line, Tumor, Cell Proliferation drug effects, DNA Fragmentation, Enzyme Activation, Gene Expression Regulation, Neoplastic, History, 16th Century, Insulin-Secreting Cells metabolism, Insulin-Secreting Cells pathology, Palmitates metabolism, Phosphorylation, Protein Serine-Threonine Kinases antagonists & inhibitors, Rats, Reverse Transcriptase Polymerase Chain Reaction, STAT3 Transcription Factor metabolism, Apoptosis drug effects, Insulinoma metabolism, Interleukin-6 metabolism, Pancreatic Neoplasms metabolism, Protein Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism, Unfolded Protein Response
- Abstract
Unfolded protein response (UPR)-mediated pancreatic beta-cell death has been described as a common mechanism by which palmitate (PA) and pro-inflammatory cytokines contribute to the development of diabetes. There are evidences that interleukin 6 (IL6) has a protective action against beta-cell death induced by pro-inflammatory cytokines; the effects of IL6 on PA-induced apoptosis have not been investigated yet. In the present study, we have demonstrated that PA selectively disrupts IL6-induced RAC-alpha serine/threonine-protein kinase (AKT) activation without interfering with signal transducer and activator of transcription 3 phosphorylation in RINm5F cells. The inability of IL6 to activate AKT in the presence of PA correlated with an inefficient protection against PA-induced apoptosis. In contrast to PA, IL6 efficiently reduced apoptosis induced by pro-inflammatory cytokines. In addition, we have demonstrated that IL6 is unable to overcome PA-stimulated UPR, as assessed by activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP) expression, X-box binding protein-1 gene mRNA splicing, and pancreatic eukaryotic initiation factor-2 alpha kinase phosphorylation, whereas no significant induction of UPR by pro-inflammatory cytokines was detected. This unconditional stimulation of UPR and apoptosis by PA was accompanied by the stimulation of CHOP and tribble3 (TRIB3) expression, irrespective of the presence of IL6. These findings suggest that IL6 is unable to protect pancreatic beta-cells from PA-induced apoptosis because it does not repress UPR activation. In this way, CHOP and ATF4 might mediate PA-induced TRIB3 expression and, by extension, the suppression of IL6 activation of pro-survival kinase AKT.
- Published
- 2010
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27. Spitz nevus: a case report and the use of dermoscopy.
- Author
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Pinheiro AM, Pereira GA, Amorin AG, Varella TC, and Friedman H
- Subjects
- Child, Preschool, Female, Humans, Dermoscopy, Nevus, Epithelioid and Spindle Cell pathology, Skin Neoplasms pathology
- Abstract
The Spitz nevus is a benign melanocytic lesion with clinical and histopathological features similar to those of melanoma. It was first described in 1948 but great controversy still remains today with respect to its diagnosis and management. The use of dermoscopy may increase diagnostic accuracy. In Spitz nevus, the most common dermoscopic finding is a starburst-like pattern, followed by globular and atypical patterns. Diagnosis must be confirmed by histopathology, particularly in atypical cases.
- Published
- 2010
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28. N-(4-Bromo-phen-yl)-2-(2-thien-yl)acetamide.
- Author
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Nogueira TC, de Souza MV, Wardell JL, Wardell SM, and Tiekink ER
- Abstract
The thienyl ring in the title compound, C(12)H(10)BrNOS, is disordered over two diagonally opposite positions, the major component having a site-occupancy factor of 0.660 (5). The mol-ecule is twisted as evidenced by the dihedral angles of 70.0 (4) and 70.5 (6)° formed between the benzene ring and the two orientations of the disordered thio-phene ring. Linear supra-molecular chains along the a axis are found in the crystal structure through the agency of N-H⋯O hydrogen bonding.
- Published
- 2009
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29. Palmitate activates insulin signaling pathway in pancreatic rat islets.
- Author
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Graciano MF, Nogueira TC, Carvalho CR, Curi R, and Carpinelli AR
- Subjects
- Animals, Caspase 3 metabolism, Cell Line, Female, Glucose pharmacology, Immunoblotting, Immunoprecipitation, In Vitro Techniques, Insulin Receptor Substrate Proteins metabolism, Islets of Langerhans metabolism, Macrophages cytology, Macrophages drug effects, Macrophages enzymology, Mitogen-Activated Protein Kinase 1 metabolism, Mitogen-Activated Protein Kinase 3 metabolism, Phosphatidylinositol 3-Kinases metabolism, Phosphorylation drug effects, Rats, STAT3 Transcription Factor metabolism, Time Factors, Islets of Langerhans drug effects, Palmitates pharmacology, Receptor, Insulin metabolism, Signal Transduction drug effects
- Abstract
Objective: To investigate the action of palmitate on insulin receptor (IR) signaling pathway in rat pancreatic islets. The following proteins were studied: IR substrate-1 and -2 (IRS1 and IRS2), phosphatidylinositol 3-kinase, extracellular signal-regulated protein kinase-1 and -2 (ERK1/2), and signal transducer and activator of transcription 3 (STAT3)., Methods: Immunoblotting and immunoprecipitation assays were used to evaluate the phosphorylation states of IRS1 and IRS2 (tyrosine [Tyr]), ERK1/2 (threonine 202 [Thr202]/Tyr204), and STAT3 (serine [Ser727])., Results: The exposure of rat pancreatic islets to 0.1-mmol/L palmitate for up to 30 minutes produced a significant increase of Tyr phosphorylation in IRS2 but not in IRS1. The association of phosphatidylinositol 3-kinase with IRS2 was also upregulated by palmitate. Exposure to 5.6-mmol/L glucose caused a gradual decrease in ERK1/2 (Thr202/Tyr204) and STAT3 (serine [Ser727]) phosphorylations after 30-minute incubation. The addition of palmitate (0.1 mmol/L), associated with 5.6-mmol/L glucose, abolished these latter effects of glucose after 15-minute incubation., Conclusions: Palmitate at physiological concentration associated with 5.6-mmol/L glucose activates IR signaling pathway in pancreatic beta cells.
- Published
- 2009
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30. Short-term modulation of extracellular signal-regulated kinase 1/2 and stress-activated protein kinase/c-Jun NH2-terminal kinase in pancreatic islets by glucose and palmitate: possible involvement of ceramide.
- Author
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Nogueira TC, Graciano MF, Anhê GF, Curi R, Bordin S, and Carpinelli AR
- Subjects
- Animals, Chromones pharmacology, Enzyme Inhibitors pharmacology, Female, Gene Expression drug effects, Genes, Immediate-Early genetics, Immunoblotting, In Vitro Techniques, Islets of Langerhans metabolism, Mitogen-Activated Protein Kinase 1 metabolism, Mitogen-Activated Protein Kinase 3 metabolism, Morpholines pharmacology, Phosphatidylinositol 3-Kinases metabolism, Phosphoinositide-3 Kinase Inhibitors, Phosphorylation drug effects, Proto-Oncogene Proteins c-fos genetics, Proto-Oncogene Proteins c-jun genetics, Rats, Reverse Transcriptase Polymerase Chain Reaction, Time Factors, Extracellular Signal-Regulated MAP Kinases metabolism, Glucose pharmacology, Islets of Langerhans drug effects, JNK Mitogen-Activated Protein Kinases metabolism, MAP Kinase Kinase 4 metabolism, Palmitates pharmacology
- Abstract
Objectives: The effect of glucose and palmitate on the phosphorylation of proteins associated with cell growth and survival (extracellular signal-regulated kinase 1/2 [ERK1/2] and stress-activated protein kinase/c-Jun NH2-terminal kinase [SAPK/JNK]) and on the expression of immediate early genes was investigated., Methods: Groups of freshly isolated rat pancreatic islets were incubated in 10-mmol/L glucose with palmitate, LY294002, or fumonisin B1 for the measurement of the phosphorylation and the content of ERK1/2, JNK/SAPK, and v-akt murine thymoma viral oncongene (AKT) (serine 473) by immunoblotting. The expressions of the immediate early genes, c-fos and c-jun, were evaluated by reverse transcription-polymerase chain reaction., Results: Glucose at 10 mmol/L induced ERK1/2 and AKT phosphorylations and decreased SAPK/JNK phosphorylation. Palmitate (0.1 mmol/L) abolished the glucose effect on ERK1/2, AKT, and SAPK/JNK phosphorylations. LY294002 caused a similar effect. The inhibitory effect of palmitate on glucose-induced ERK1/2 and AKT phosphorylation changes was not observed in the presence of fumonisin B1. Glucose increased c-fos and decreased c-jun expressions. Palmitate and LY294002 abolished these latter glucose effects. The presence of fumonisin B1 abolished the effect induced by palmitate on c-jun expression., Conclusions: Our results suggest that short-term changes of mitogen-activated protein kinase and AKT signaling pathways and c-fos and c-jun expressions caused by glucose are abolished by palmitate through phosphatidylinositol 3-kinase inhibition via ceramide synthesis.
- Published
- 2009
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31. Delayed diagnosis of multibacillary leprosy: a report of eight cases.
- Author
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Trindade MA, Varella TC, Cisneros CG, Bottini V, and Moura AK
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Delayed Diagnosis, Leprosy, Multibacillary diagnosis
- Abstract
Leprosy is an important public health problem in Brazil. However, this disease is still poorly diagnosed in its early stages, leading to permanent disability and disfigurement. We examined eight patients with clinical and histological diagnosis of multibacillary leprosy who were being treated for other diseases for about three years without clinical hypothesis of leprosy. These cases illustrate the importance of medical education and public information about leprosy's signs and symptoms for prompt recognition and treatment, which are necessary to prevent permanent disabilities and eradicate the disease.
- Published
- 2009
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32. Involvement of phosphatidylinositol-3 kinase/AKT/PKCzeta/lambda pathway in the effect of palmitate on glucose-induced insulin secretion.
- Author
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Nogueira TC, Anhê GF, Carvalho CR, Curi R, Bordin S, and Carpinelli AR
- Subjects
- Androstadienes pharmacology, Animals, Ceramides metabolism, Chromones pharmacology, Female, Fumonisins pharmacology, Insulin Secretion, Islets of Langerhans drug effects, Islets of Langerhans metabolism, Morpholines pharmacology, Phosphoinositide-3 Kinase Inhibitors, Phosphorylation, Protein Kinase Inhibitors pharmacology, Rats, Signal Transduction, Up-Regulation, Wortmannin, Glucose metabolism, Insulin metabolism, Islets of Langerhans enzymology, Isoenzymes metabolism, Molecular Chaperones metabolism, Palmitic Acid metabolism, Phosphatidylinositol 3-Kinases metabolism, Protein Kinase C metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Objectives: In the present study, a novel pathway by which palmitate potentiates glucose-induced insulin secretion by pancreatic beta cells was investigated., Methods: Groups of freshly isolated islets were incubated in 10 mM glucose with palmitate, LY294002, wortmannin, and fumonisin B1 for measurement of insulin secretion by radioimmunoassay (RIA). Also, phosphorylation and content of AKT and PKC proteins were evaluated by immunoblotting., Results: Glucose plus palmitate and glucose plus LY294002 or wortmannin (PI3K inhibitors) increased glucose-induced insulin secretion by isolated pancreatic islets. Glucose at 10 mM induced AKT and PKCzeta/lambda phosphorylation. Palmitate (0.1 mM) abolished glucose stimulation of AKT and PKCzeta/lambda phosphorylation possibly through PI3K inhibition because both LY294002 (50 microM) and wortmannin (100 nM) caused the same effect. The inhibitory effect of palmitate on glucose-induced AKT and PKCzeta/lambda phosphorylation and the stimulatory effect of palmitate on glucose-induced insulin secretion were not observed in the presence of fumonisin B1, an inhibitor of ceramide synthesis., Conclusions: These findings support the proposition that palmitate increases insulin release in the presence of 10 mM glucose by inhibiting PI3K activity through a mechanism that involves ceramide synthesis.
- Published
- 2008
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33. Retinal removal up-regulates cannabinoid CB(1) receptors in the chick optic tectum.
- Author
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Chaves GP, Nogueira TC, Britto LR, Bordin S, and Torrão AS
- Subjects
- Animals, Animals, Newborn, Apoptosis physiology, Chickens, Fluoresceins, In Situ Nick-End Labeling methods, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, Nerve Degeneration metabolism, Organic Chemicals, RNA, Messenger metabolism, Receptor, Cannabinoid, CB1 genetics, Retina growth & development, Time Factors, Gene Expression Regulation, Developmental physiology, Receptor, Cannabinoid, CB1 metabolism, Retina physiology, Superior Colliculi metabolism, Up-Regulation physiology
- Abstract
The endocannabinoid system has been implicated in several neurobiological processes, including neurodegeneration and neuroprotection. The aim of this study was to evaluate the effects of unilateral retinal ablation on the expression of the cannabinoid receptor subtype 1 (CB(1)) at both protein and mRNA levels in the optic tectum of the adult chick brain. After different survival times postlesion (2-30 days), the chick brains were subjected to immunohistochemical, immunoblotting, and real-time PCR procedures to evaluate CB(1) expression. TUNEL and Fluoro-Jade B were used to verify the possible occurrence of cell death, and immunostaining for the microtubule-associated protein MAP-2 was performed to verify possible dendritic remodeling after lesions. No cell death could be observed in the deafferented tectum, at least up to 30 days postlesion, although Fluoro-Jade B could reveal degenerating axons and terminals. Retinal ablation seems to generate an increase of CB(1) protein in the optic tectum and other retinorecipient visual areas, which paralleled an increase in MAP-2 staining. On the other hand, CB(1) mRNA levels were not changed after retinal ablation. Our results reveal that CB(1) expression in visual structures of the adult chick brain may be negatively regulated by the retinal innervation. The increase of CB(1) receptor expression observed after retinal removal indicates that these receptors are not presynaptic in retinal axons projecting to the tectum and suggests a role of the cannabinoid system in plasticity processes ensuing after lesions.
- Published
- 2008
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34. Synthesis and biological evaluation of N-(aryl)-2-thiophen-2-ylacetamides series as a new class of antitubercular agents.
- Author
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Silva Lourenço MC, Rodrigues Vicente F, de Oliveira Henriques Md, Peixoto Candéa AL, Borges Gonçalves RS, Nogueira TC, de Lima Ferreira M, and Nora de Souza MV
- Subjects
- Acetamides chemistry, Acetamides classification, Animals, Antitubercular Agents chemistry, Antitubercular Agents classification, Cell Line, Macrophages drug effects, Mice, Molecular Structure, Structure-Activity Relationship, Acetamides chemical synthesis, Acetamides pharmacology, Antitubercular Agents chemical synthesis, Antitubercular Agents pharmacology, Thiophenes chemistry
- Abstract
The present article describes a series of 21 N-(aryl)-2-thiophen-2-ylacetamides, which were synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis, and the activity expressed as the minimum inhibitory concentration (MIC) in mug/mL. The compounds 2, 3, 7, 8, 11, 12, 15, 16, and 20 exhibited activity between 25 and 100 microg/mL and could be a good start point to find new lead compounds in the fight against multidrug resistant tuberculosis.
- Published
- 2007
- Full Text
- View/download PDF
35. Signal transducer and activator of transcription 3-regulated sarcoendoplasmic reticulum Ca2+-ATPase 2 expression by prolactin and glucocorticoids is involved in the adaptation of insulin secretory response during the peripartum period.
- Author
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Anhê GF, Nogueira TC, Nicoletti-Carvalho JE, Lellis-Santos C, Barbosa HC, Cipolla-Neto J, Bosqueiro JR, Boschero AC, and Bordin S
- Subjects
- Adaptation, Physiological, Animals, Blotting, Western, Cell Line, Cells, Cultured, Dexamethasone pharmacology, Female, Gene Expression drug effects, Insulin analysis, Insulin Secretion, Islets of Langerhans chemistry, Lactation physiology, Oligonucleotides, Antisense genetics, Phosphorylation, Pregnancy, Prolactin genetics, RNA, Messenger analysis, Rats, Reverse Transcriptase Polymerase Chain Reaction, STAT3 Transcription Factor antagonists & inhibitors, STAT3 Transcription Factor genetics, Sarcoplasmic Reticulum Calcium-Transporting ATPases analysis, Sarcoplasmic Reticulum Calcium-Transporting ATPases genetics, Signal Transduction drug effects, Transfection methods, Glucocorticoids metabolism, Insulin metabolism, Islets of Langerhans metabolism, Prolactin metabolism, STAT3 Transcription Factor metabolism, Sarcoplasmic Reticulum Calcium-Transporting ATPases metabolism
- Abstract
During pregnancy, the maternal endocrine pancreas undergoes, as a consequence of placental lactogens and prolactin (PRL) action, functional changes that are characterized by increased glucose-induced insulin secretion. After delivery, the maternal endocrine pancreas rapidly returns to non-pregnant state, which is mainly attributed to the increased serum levels of glucocorticoids (GCs). Although GCs are known to decrease insulin secretion and counteract PRL action, the mechanisms for these effects are poorly understood. We have previously demonstrated that signal transducer and activator of transcription 3 (STAT3) is increased in islets treated with PRL. In the present study, we show that STAT3 expression and serine phosphorylation are increased in pancreatic islets at the end of pregnancy (P19). STAT3 serine phosphorylation rapidly returned to basal levels 3 days after delivery (L3). The expression of the sarcoendoplasmic reticulum Ca(2+)-ATPase 2 (SERCA2), a crucial protein involved in the regulation of calcium handling in beta-cells, was also increased in P19, returning to basal levels at L3. PRL increased SERCA2 and STAT3 expressions and STAT3 serine phosphorylation in RINm5F cells. The upregulation of SERCA2 by PRL was abolished after STAT3 knockdown. Moreover, PRL-induced STAT3 serine phosphorylation and SERCA2 expression were inhibited by dexamethasone (DEX). Insulin secretion from islets of P19 rats pre-incubated with thapsigargin and L3 rats showed a dramatic suppression of first phase of insulin release. The present results indicate that PRL regulates SERCA2 expression by a STAT3-dependent mechanism. PRL effect is counteracted by DEX and might contribute to the adaptation of maternal endocrine pancreas during the peripartum period.
- Published
- 2007
- Full Text
- View/download PDF
36. Aortic coarctation hypertension induces fibroblast growth factor-2 immunoreactivity in the stimulated nucleus tractus solitarii.
- Author
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Fior-Chadi DR, Varella TC, Maximino JR, and Chadi G
- Subjects
- Animals, Blood Pressure, Glial Fibrillary Acidic Protein metabolism, Male, Peroxidase metabolism, Proto-Oncogene Proteins c-fos metabolism, Rats, Rats, Wistar, Aortic Coarctation pathology, Fibroblast Growth Factor 2 immunology, Hypertension pathology, Solitary Nucleus metabolism
- Abstract
The actions of neurotrophic factors i.e. basic fibroblast growth factor (bFGF, FGF-2) to neurons are related not only to neuronal development and maintenance but also to synaptic plasticity regarding neurotransmission. We analyzed here the levels of FGF-2 immunoreactivity in the nucleus tractus solitarii (NTS) of Wistar Kyoto rats in response to alterations of neuronal activity promoted by the stimulation of the baroreceptor reflex following an aortic coarctation-induced-hypertension. The FGF-2 immunoreactivity (IR) was found in the cytoplasm of the neurons and in the nuclei of the glial cells in the NTS. A large number of NTS neurons expressed FOS immunoreactivity 4 h after coarctation, as an indication of neuronal activity. Stereological methods showed an increased number of FGF-2 immunoreactive (ir) neuronal profiles (90%) and glial profiles (149%) in the NTS of the 72 h aortic coarctated rats. 1-week later, FGF-2 ir neurons were still increased (54%) but no change was found in the number of FGF-2 ir glial profiles. The double immunoperoxidase method revealed that the majority of the FGF-2 ir glial cells was glial fibrillary acidic protein (GFAP) positive astrocytes. GFAP immunohistochemistry showed an astroglial reaction at 72 h time-interval (55%) but not 1 week after stimulation. The number of the cresyl violet positive neurons and OX42 ir profiles (marker of activated microglia) in the NTS of coarctated rats were not different from control by 1 week and 1 month after the surgery, indicating a lack of NTS injury in this period following coarctation hypertension. FGF-2 may be an important neurotrophic factor in areas involved in the control of blood pressure. The increased FGF-2 IR in the NTS cells following neuronal stimulation may represent trophic and plastic adaptive responses in this nucleus in an autocrine/paracrine fashion.
- Published
- 2007
- Full Text
- View/download PDF
37. ERK3 associates with MAP2 and is involved in glucose-induced insulin secretion.
- Author
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Anhê GF, Torrão AS, Nogueira TC, Caperuto LC, Amaral ME, Medina MC, Azevedo-Martins AK, Carpinelli AR, Carvalho CR, Curi R, Boschero AC, and Bordin S
- Subjects
- Animals, Cells, Cultured, Female, Glucose metabolism, Insulin-Secreting Cells drug effects, Models, Animal, Oligonucleotides, Antisense, Phosphorylation, Pregnancy, Rats, Rats, Wistar, Tetradecanoylphorbol Acetate pharmacology, Up-Regulation, Insulin metabolism, Insulin-Secreting Cells metabolism, Microtubule-Associated Proteins metabolism, Mitogen-Activated Protein Kinase 6 biosynthesis, Receptors, Prolactin metabolism
- Abstract
The adaptation of pancreatic islets to pregnancy includes increased beta cell proliferation, expansion of islet mass, and increased insulin synthesis and secretion. Most of these adaptations are induced by prolactin (PRL). We have previously described that in vitro PRL treatment increases ERK3 expression in isolated rat pancreatic islets. This study shows that ERK3 is also upregulated during pregnancy. Islets from pregnant rats treated with antisense oligonucleotide targeted to the PRL receptor displayed a significant reduction in ERK3 expression. Immunohistochemical double-staining showed that ERK3 expression is restricted to pancreatic beta cells. Transfection with antisense oligonucleotide targeted to ERK3 abolished the insulin secretion stimulated by glucose in rat islets and by PMA in RINm5F cells. Therefore, we examined the participation of ERK3 in the activation of a cellular target involved in secretory events, the microtubule associated protein MAP2. PMA induced ERK3 phosphorylation that was companied by an increase in ERK3/MAP2 association and MAP2 phosphorylation. These observations provide evidence that ERK3 is involved in the regulation of stimulus-secretion coupling in pancreatic beta cells.
- Published
- 2006
- Full Text
- View/download PDF
38. Erysipeloid.
- Author
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Varella TC and Nico MM
- Subjects
- Animals, Anti-Bacterial Agents therapeutic use, Erysipeloid drug therapy, Female, Fishes microbiology, Humans, Middle Aged, Penicillin G Procaine therapeutic use, Erysipeloid diagnosis
- Published
- 2005
- Full Text
- View/download PDF
39. Characterization of the insulinotropic action of a phospholipase A2 isolated from Crotalus durissus collilineatus rattlesnake venom on rat pancreatic islets.
- Author
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Nogueira TC, Ferreira F, Toyama MH, Stoppiglia LF, Marangoni S, Boschero AC, and Carneiro EM
- Subjects
- Animals, Arachidonic Acid metabolism, Crotalid Venoms pharmacology, Crotoxin pharmacology, In Vitro Techniques, Insulin Secretion, Islets of Langerhans metabolism, Male, Phospholipases A chemistry, Phospholipases A isolation & purification, Phospholipases A2, Rats, Rats, Wistar, Crotalid Venoms chemistry, Insulin metabolism, Islets of Langerhans drug effects, Phospholipases A pharmacology
- Abstract
The ability of PLA2 and crotapotin, isolated from Crotalus durissus collilineatus rattlesnake venom, to stimulate insulin secretion from isolated rat islets was examined. PLA2 and crotapotin stimulated insulin secretion at 2.8 mmol/L glucose, whereas at a high glucose concentrations (16.7 mmol/L) only PLA2 stimulated secretion. Nifedipine (10 micromol/L) did not alter the ability of PLA2 to increase insulin secretion stimulated by a depolarizing concentration of K+ (30 mmol/L). PLA2 did not affect 14CO2 production but significantly increased the efflux of arachidonic acid from isolated islets. These results indicate that PLA2-stimulated secretion is not dependent on an additional influx of Ca2+ through L-type Ca(2+)-channels but rather is associated with arachidonic acid formation in pancreatic islets.
- Published
- 2005
- Full Text
- View/download PDF
40. Schnitzler's syndrome without monoclonal gammopathy.
- Author
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Varella TC, Nishimura MY, Machado MC, de Moraes-Vasconcelos D, and Rivitti EA
- Subjects
- Adult, Anti-Inflammatory Agents, Non-Steroidal administration & dosage, Arthralgia complications, Arthralgia drug therapy, Diagnosis, Differential, Drug Therapy, Combination, Humans, Male, Prednisone administration & dosage, Syndrome, Thalidomide administration & dosage, Urticaria etiology, Urticaria pathology, Arthralgia diagnosis, Immunoglobulin M
- Published
- 2005
- Full Text
- View/download PDF
41. Photolocalized varicella.
- Author
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Varella TC and Machado MC
- Subjects
- Acyclovir therapeutic use, Antiviral Agents therapeutic use, Chickenpox drug therapy, Child, Preschool, Female, Fever virology, Humans, Chickenpox pathology, Photosensitivity Disorders drug therapy, Photosensitivity Disorders pathology, Sunlight adverse effects
- Published
- 2004
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