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1.
Hepatology ; 73(2): 606-624, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32329085

RESUMO

BACKGROUND AND AIMS: G protein-coupled receptor (GPR) 55 is a putative cannabinoid receptor, and l-α-lysophosphatidylinositol (LPI) is its only known endogenous ligand. Although GPR55 has been linked to energy homeostasis in different organs, its specific role in lipid metabolism in the liver and its contribution to the pathophysiology of nonalcoholic fatty liver disease (NAFLD) remains unknown. APPROACH AND RESULTS: We measured (1) GPR55 expression in the liver of patients with NAFLD compared with individuals without obesity and without liver disease, as well as animal models with steatosis and nonalcoholic steatohepatitis (NASH), and (2) the effects of LPI and genetic disruption of GPR55 in mice, human hepatocytes, and human hepatic stellate cells. Notably, we found that circulating LPI and liver expression of GPR55 were up-regulated in patients with NASH. LPI induced adenosine monophosphate-activated protein kinase activation of acetyl-coenzyme A carboxylase (ACC) and increased lipid content in human hepatocytes and in the liver of treated mice by inducing de novo lipogenesis and decreasing ß-oxidation. The inhibition of GPR55 and ACCα blocked the effects of LPI, and the in vivo knockdown of GPR55 was sufficient to improve liver damage in mice fed a high-fat diet and in mice fed a methionine-choline-deficient diet. Finally, LPI promoted the initiation of hepatic stellate cell activation by stimulating GPR55 and activation of ACC. CONCLUSIONS: The LPI/GPR55 system plays a role in the development of NAFLD and NASH by activating ACC.


Assuntos
Lisofosfolipídeos/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/complicações , Receptores de Canabinoides/metabolismo , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/metabolismo , Adulto , Idoso , Animais , Biópsia , Agonistas de Receptores de Canabinoides/farmacologia , Linhagem Celular , Estudos de Coortes , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Células Estreladas do Fígado , Hepatócitos , Humanos , Lipogênese/efeitos dos fármacos , Fígado/patologia , Lisofosfolipídeos/sangue , Masculino , Camundongos , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade/sangue , Obesidade/metabolismo , Receptores de Canabinoides/genética , Regulação para Cima
2.
Int J Mol Sci ; 23(6)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35328539

RESUMO

Weight gain is a hallmark of decreased estradiol (E2) levels because of menopause or following surgical ovariectomy (OVX) at younger ages. Of note, this weight gain tends to be around the abdomen, which is frequently associated with impaired metabolic homeostasis and greater cardiovascular risk in both rodents and humans. However, the molecular underpinnings and the neuronal basis for these effects remain to be elucidated. The aim of this study is to elucidate whether the kappa-opioid receptor (k-OR) system is involved in mediating body weight changes associated with E2 withdrawal. Here, we document that body weight gain induced by OVX occurs, at least partially, in a k-OR dependent manner, by modulation of energy expenditure independently of food intake as assessed in Oprk1-/-global KO mice. These effects were also observed following central pharmacological blockade of the k-OR system using the k-OR-selective antagonist PF-04455242 in wild type mice, in which we also observed a decrease in OVX-induced weight gain associated with increased UCP1 positive immunostaining in brown adipose tissue (BAT) and browning of white adipose tissue (WAT). Remarkably, the hypothalamic mTOR pathway plays an important role in regulating weight gain and adiposity in OVX mice. These findings will help to define new therapies to manage metabolic disorders associated with low/null E2 levels based on the modulation of central k-OR signaling.


Assuntos
Ingestão de Alimentos , Receptores Opioides kappa , Tecido Adiposo Marrom/metabolismo , Animais , Peso Corporal , Metabolismo Energético , Estrogênios/metabolismo , Feminino , Humanos , Camundongos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/metabolismo , Ovariectomia/efeitos adversos , Receptores Opioides kappa/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Aumento de Peso
3.
Proc Natl Acad Sci U S A ; 107(27): 12168-73, 2010 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-20566863

RESUMO

As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.


Assuntos
Genoma Bacteriano/genética , Genoma de Inseto/genética , Pediculus/genética , Pediculus/microbiologia , Animais , Enterobacteriaceae/genética , Genes Bacterianos/genética , Genes de Insetos/genética , Genômica/métodos , Humanos , Infestações por Piolhos/parasitologia , Dados de Sequência Molecular , Análise de Sequência de DNA , Simbiose
4.
Nat Commun ; 12(1): 6910, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34824211

RESUMO

Most cancers are characterized by the somatic acquisition of genomic rearrangements during tumour evolution that eventually drive the oncogenesis. Here, using multiplatform sequencing technologies, we identify and characterize a remarkable mutational mechanism in human hepatocellular carcinoma caused by Hepatitis B virus, by which DNA molecules from the virus are inserted into the tumour genome causing dramatic changes in its configuration, including non-homologous chromosomal fusions, dicentric chromosomes and megabase-size telomeric deletions. This aberrant mutational mechanism, present in at least 8% of all HCC tumours, can provide the driver rearrangements that a cancer clone requires to survive and grow, including loss of relevant tumour suppressor genes. Most of these events are clonal and occur early during liver cancer evolution. Real-time timing estimation reveals some HBV-mediated rearrangements occur as early as two decades before cancer diagnosis. Overall, these data underscore the importance of characterising liver cancer genomes for patterns of HBV integration.


Assuntos
Carcinoma Hepatocelular/genética , DNA Viral , Genoma Humano , Vírus da Hepatite B/genética , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/virologia , Regulação Neoplásica da Expressão Gênica , Humanos , Integração Viral , Sequenciamento Completo do Genoma
5.
Pathol Int ; 60(12): 792-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21140588

RESUMO

Fluorescent in situ hybridization (FISH) is a very useful tool for diagnostic and prognostic purposes in pathology. However, many laboratories still experience troubles when applying FISH to paraffin material. To overcome these difficulties, different pretreatments which include enzymatic digestion have been described. Usually, previous to digestion, a heating step is performed. The aim of this study was to compare the efficiency of the heating step with different buffers and different heating methods. We conclude that the main factor in the heating pretreatment is the temperature control, irrespective of the buffer used. Best results are obtained with any buffer by heating the slides to 99°C for 15 min followed by 10 min at room temperature.


Assuntos
Calefação/métodos , Hibridização in Situ Fluorescente/métodos , Linfoma/genética , Soluções Tampão , Humanos , Inclusão em Parafina , Análise Serial de Tecidos
6.
Nat Genet ; 52(3): 306-319, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32024998

RESUMO

About half of all cancers have somatic integrations of retrotransposons. Here, to characterize their role in oncogenesis, we analyzed the patterns and mechanisms of somatic retrotransposition in 2,954 cancer genomes from 38 histological cancer subtypes within the framework of the Pan-Cancer Analysis of Whole Genomes (PCAWG) project. We identified 19,166 somatically acquired retrotransposition events, which affected 35% of samples and spanned a range of event types. Long interspersed nuclear element (LINE-1; L1 hereafter) insertions emerged as the first most frequent type of somatic structural variation in esophageal adenocarcinoma, and the second most frequent in head-and-neck and colorectal cancers. Aberrant L1 integrations can delete megabase-scale regions of a chromosome, which sometimes leads to the removal of tumor-suppressor genes, and can induce complex translocations and large-scale duplications. Somatic retrotranspositions can also initiate breakage-fusion-bridge cycles, leading to high-level amplification of oncogenes. These observations illuminate a relevant role of L1 retrotransposition in remodeling the cancer genome, with potential implications for the development of human tumors.


Assuntos
Carcinogênese/genética , Rearranjo Gênico/genética , Genoma Humano/genética , Elementos Nucleotídeos Longos e Dispersos/genética , Neoplasias/genética , Retroelementos/genética , Humanos , Neoplasias/patologia
7.
Diagn Mol Pathol ; 17(1): 59-63, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18303405

RESUMO

Fluorescence in situ hybridization (FISH) is a useful cytogenetic technique for the detection of chromosome aberrations. However, applying this technique routinely on paraffin-embedded tissue is hampered by technical problems. The efficiency of hybridization is influenced by formalin fixation time, and this may vary considerably between specimens. We present a simple method for improving hybridization by microscopically monitoring the time of enzymatic digestion. To establish optimal digestion time, enzymatic digestion was stopped at 3-minute intervals for biopsies and 10-minute intervals for autopsies in 24 paraffin-embedded samples. At every stop, tissue morphology was examined under light microscopy to determine if observed changes could be correlated with subsequent FISH results. The appearance of fernlike formations was found to mark the optimal digestion time that produced the strongest hybridization signals. Using this method of digestion time control, an additional 41 cases were evaluated for FISH with various types of probe. Monitoring under the microscope could be more spaced if the morphology did not change after the first visual control and could be adapted to the type of sample (in general, endoscopic samples, total digestion time of about 10 min; routine biopsies, 15 to 30 min; autopsy samples, 20 to 40 min). In every case, the appearance of the fernlike pattern correlated with proper hybridization signal. Monitoring digestion time for the appearance of fernlike structures is a useful method for improving reproducibility of FISH technique on paraffin-embedded samples. It is particularly useful when dealing with samples under heterogeneous fixation conditions (consultations, autopsies, etc.), because it eliminates the need for repetition.


Assuntos
Endopeptidase K/metabolismo , Hibridização in Situ Fluorescente/métodos , Inclusão em Parafina , Fixação de Tecidos , Humanos , Linfoma não Hodgkin/diagnóstico , Linfoma não Hodgkin/genética , Reprodutibilidade dos Testes , Fatores de Tempo
9.
J Mol Endocrinol ; 58(3): R191-R202, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28196832

RESUMO

GPR55 is a G-protein-coupled receptor (GPCR) that has been identified as a new cannabinoid receptor. Given the wide localization of GPR55 in brain and peripheral tissues, this receptor has emerged as a regulator of multiple biological actions. Lysophosphatidylinositol (LPI) is generally accepted as the endogenous ligand of GPR55. In this review, we will focus on the role of GPR55 in energy balance and glucose metabolism. We will summarize its actions on feeding, nutrient partitioning, gastrointestinal motility and insulin secretion in preclinical models and the scarce data available in humans. The potential of GPR55 to become a new pharmaceutical target to treat obesity and type 2 diabetes, as well as the foreseeing difficulties are also discussed.


Assuntos
Metabolismo Energético , Receptores Acoplados a Proteínas G/metabolismo , Tecido Adiposo/metabolismo , Animais , Canabinoides/metabolismo , Canabinoides/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Descoberta de Drogas , Metabolismo Energético/efeitos dos fármacos , Regulação da Expressão Gênica , Humanos , Ligantes , Terapia de Alvo Molecular , Especificidade de Órgãos/genética , Receptores de Canabinoides/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/genética , Roedores
10.
Genome Biol ; 15(9): 459, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25244985

RESUMO

BACKGROUND: Anopheles stephensi is the key vector of malaria throughout the Indian subcontinent and Middle East and an emerging model for molecular and genetic studies of mosquito-parasite interactions. The type form of the species is responsible for the majority of urban malaria transmission across its range. RESULTS: Here, we report the genome sequence and annotation of the Indian strain of the type form of An. stephensi. The 221 Mb genome assembly represents more than 92% of the entire genome and was produced using a combination of 454, Illumina, and PacBio sequencing. Physical mapping assigned 62% of the genome onto chromosomes, enabling chromosome-based analysis. Comparisons between An. stephensi and An. gambiae reveal that the rate of gene order reshuffling on the X chromosome was three times higher than that on the autosomes. An. stephensi has more heterochromatin in pericentric regions but less repetitive DNA in chromosome arms than An. gambiae. We also identify a number of Y-chromosome contigs and BACs. Interspersed repeats constitute 7.1% of the assembled genome while LTR retrotransposons alone comprise more than 49% of the Y contigs. RNA-seq analyses provide new insights into mosquito innate immunity, development, and sexual dimorphism. CONCLUSIONS: The genome analysis described in this manuscript provides a resource and platform for fundamental and translational research into a major urban malaria vector. Chromosome-based investigations provide unique perspectives on Anopheles chromosome evolution. RNA-seq analysis and studies of immunity genes offer new insights into mosquito biology and mosquito-parasite interactions.


Assuntos
Anopheles/genética , Insetos Vetores/genética , Animais , Anopheles/metabolismo , Mapeamento Cromossômico , Cromossomos de Insetos/genética , Análise por Conglomerados , Evolução Molecular , Genoma de Inseto , Humanos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Malária/transmissão , Filogenia , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Sintenia , Transcriptoma , População Urbana
11.
Science ; 345(6196): 1251343, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25082706

RESUMO

Long interspersed nuclear element-1 (L1) retrotransposons are mobile repetitive elements that are abundant in the human genome. L1 elements propagate through RNA intermediates. In the germ line, neighboring, nonrepetitive sequences are occasionally mobilized by the L1 machinery, a process called 3' transduction. Because 3' transductions are potentially mutagenic, we explored the extent to which they occur somatically during tumorigenesis. Studying cancer genomes from 244 patients, we found that tumors from 53% of the patients had somatic retrotranspositions, of which 24% were 3' transductions. Fingerprinting of donor L1s revealed that a handful of source L1 elements in a tumor can spawn from tens to hundreds of 3' transductions, which can themselves seed further retrotranspositions. The activity of individual L1 elements fluctuated during tumor evolution and correlated with L1 promoter hypomethylation. The 3' transductions disseminated genes, exons, and regulatory elements to new locations, most often to heterochromatic regions of the genome.


Assuntos
Elementos de DNA Transponíveis , Elementos Nucleotídeos Longos e Dispersos , Neoplasias/genética , Transdução Genética , Carcinogênese/genética , Cromatina/química , Éxons , Genoma Humano , Humanos , Mutagênese Insercional , Translocação Genética
12.
PLoS One ; 6(1): e16328, 2011 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-21283637

RESUMO

Ty3/gypsy elements represent one of the most abundant and diverse LTR-retrotransposon (LTRr) groups in the Anopheles gambiae genome, but their evolutionary dynamics have not been explored in detail. Here, we conduct an in silico analysis of the distribution and abundance of the full complement of 1045 copies in the updated AgamP3 assembly. Chromosomal distribution of Ty3/gypsy elements is inversely related to arm length, with densities being greatest on the X, and greater on the short versus long arms of both autosomes. Taking into account the different heterochromatic and euchromatic compartments of the genome, our data suggest that the relative abundance of Ty3/gypsy LTRrs along each chromosome arm is determined mainly by the different proportions of heterochromatin, particularly pericentric heterochromatin, relative to total arm length. Additionally, the breakpoint regions of chromosomal inversion 2La appears to be a haven for LTRrs. These elements are underrepresented more than 7-fold in euchromatin, where 33% of the Ty3/gypsy copies are associated with genes. The euchromatin on chromosome 3R shows a faster turnover rate of Ty3/gypsy elements, characterized by a deficit of proviral sequences and the lowest average sequence divergence of any autosomal region analyzed in this study. This probably reflects a principal role of purifying selection against insertion for the preservation of longer conserved syntenyc blocks with adaptive importance located in 3R. Although some Ty3/gypsy LTRrs show evidence of recent activity, an important fraction are inactive remnants of relatively ancient insertions apparently subject to genetic drift. Consistent with these computational predictions, an analysis of the occupancy rate of putatively older insertions in natural populations suggested that the degenerate copies have been fixed across the species range in this mosquito, and also are shared with the sibling species Anopheles arabiensis.


Assuntos
Anopheles/genética , Evolução Molecular , Genoma de Inseto/genética , Retroelementos/genética , Animais , Cromossomos de Insetos , Eucromatina , Deriva Genética , Mutagênese Insercional , DNA Polimerase Dirigida por RNA , Sequências Repetidas Terminais
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