RESUMO
BACKGROUND & AIMS: Alcohol disturbs hepatic lipid synthesis and transport, but the role of lipid dysfunction in alcohol-related liver disease (ALD) is unclear. In this biopsy-controlled, prospective, observational study, we characterized the liver and plasma lipidomes in patients with early ALD. METHODS: We performed mass spectrometry-based lipidomics of paired liver and plasma samples from 315 patients with ALD and of plasma from 51 matched healthy controls. We associated lipid levels with histologic fibrosis, inflammation, and steatosis with correction for multiple testing and adjustment for confounders. We further investigated sphingolipid regulation by means of quantitative real-time polymerase chain reaction sequencing of microRNA, prediction of liver-related events, and tested causality with Mendelian randomization. RESULTS: We detected 198 lipids in the liver and 236 lipids in the circulation from 18 lipid classes. Most sphingolipids (sphingomyelins and ceramides) and phosphocholines were co-down-regulated in both liver and plasma, where lower abundance correlated with higher fibrosis stage. Sphingomyelins showed the most pronounced negative correlation to fibrosis, mirrored by negative correlations in both liver and plasma with hepatic inflammation. Reduced sphingomyelins predicted future liver-related events. This seemed to be characteristic of "pure ALD," as sphingomyelin levels were higher in patients with concomitant metabolic syndrome and ALD/nonalcoholic fatty liver disease overlap. Mendelian randomization in FinnGen and UK Biobanks indicated ALD as the cause of low sphingomyelins, and alcohol use disorder did not correlate with genetic susceptibility to low sphingomyelin levels. CONCLUSIONS: Alcohol-related liver fibrosis is characterized by selective and progressive lipid depletion in liver and blood, particularly sphingomyelins, which also associates with progression to liver-related events.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Esfingolipídeos , Humanos , Esfingolipídeos/metabolismo , Esfingomielinas/metabolismo , Estudos Prospectivos , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Fígado/patologia , Etanol/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Fibrose , Inflamação/metabolismoRESUMO
Gene expression dictates fundamental cellular processes and its de-regulation leads to pathological conditions. A key contributor to the fine-tuning of gene expression is Dicer, an RNA-binding protein (RBPs) that forms complexes and affects transcription by acting at the post-transcriptional level via the targeting of mRNAs by Dicer-produced small non-coding RNAs. This review aims to present the contribution of Dicer protein in a wide spectrum of human pathological conditions, including cancer, neurological, autoimmune, reproductive and cardiovascular diseases, as well as viral infections. Germline mutations of Dicer have been linked to Dicer1 syndrome, a rare genetic disorder that predisposes to the development of both benign and malignant tumors, but the exact correlation of Dicer protein expression within the different cancer types is unclear, and there are contradictions in the data. Downregulation of Dicer is related to Geographic atrophy (GA), a severe eye-disease that is a leading cause of blindness in industrialized countries, as well as to psychiatric and neurological diseases such as depression and Parkinson's disease, respectively. Both loss and upregulation of Dicer protein expression is implicated in severe autoimmune disorders, including psoriasis, ankylosing spondylitis, rheumatoid arthritis, multiple sclerosis and autoimmune thyroid diseases. Loss of Dicer contributes to cardiovascular diseases and causes defective germ cell differentiation and reproductive system abnormalities in both sexes. Dicer can also act as a strong antiviral with a crucial role in RNA-based antiviral immunity. In conclusion, Dicer is an essential enzyme for the maintenance of physiology due to its pivotal role in several cellular processes, and its loss or aberrant expression contributes to the development of severe human diseases. Further exploitation is required for the development of novel, more effective Dicer-based diagnostic and therapeutic strategies, with the goal of new clinical benefits and better quality of life for patients.
Assuntos
RNA Helicases DEAD-box/genética , MicroRNAs/genética , RNA Mensageiro/genética , Pequeno RNA não Traduzido/genética , Ribonuclease III/genética , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/terapia , Diferenciação Celular/genética , Humanos , Neoplasias/genética , Neoplasias/terapia , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/terapia , Viroses/genética , Viroses/terapiaRESUMO
Regulation of gene expression has emerged as a fundamental element of transcript homeostasis. Key effectors in this process are the Argonautes (AGOs), highly specialized RNA-binding proteins (RBPs) that form complexes, such as the RNA-Induced Silencing Complex (RISC). AGOs dictate post-transcriptional gene-silencing by directly loading small RNAs and repressing their mRNA targets through small RNA-sequence complementarity. The four human highly-conserved family-members (AGO1, AGO2, AGO3, and AGO4) demonstrate multi-faceted and versatile roles in transcriptome's stability, plasticity, and functionality. The post-translational modifications of AGOs in critical amino acid residues, the nucleotide polymorphisms and mutations, and the deregulation of expression and interactions are tightly associated with aberrant activities, which are observed in a wide spectrum of pathologies. Through constantly accumulating information, the AGOs' fundamental engagement in multiple human diseases has recently emerged. The present review examines new insights into AGO-driven pathology and AGO-deregulation patterns in a variety of diseases such as in viral infections and propagations, autoimmune diseases, cancers, metabolic deficiencies, neuronal disorders, and human infertility. Altogether, AGO seems to be a crucial contributor to pathogenesis and its targeting may serve as a novel and powerful therapeutic tool for the successful management of diverse human diseases in the clinic.
Assuntos
Proteínas Argonautas/metabolismo , Regulação da Expressão Gênica , Interferência de RNA , Complexo de Inativação Induzido por RNA/genética , Animais , Doenças Autoimunes/tratamento farmacológico , Fatores de Iniciação em Eucariotos/metabolismo , Inativação Gênica , Humanos , Infertilidade/metabolismo , Neoplasias/metabolismo , Doenças do Sistema Nervoso/tratamento farmacológico , Neurônios/metabolismo , Obesidade/metabolismo , Conformação Proteica , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
Hyperplasia and hypertrophy are the two mechanisms by which muscle develops and grows. We study these two mechanisms, during the early development of white muscle in Sparus aurata, by means of histology and the expression of structural and regulatory genes. A clear stage of stratified hyperplasia was identified early in the development of gilthead sea bream but ceased by 35 dph when hypertrophy took over. Mosaic recruitment of new white fibers began as soon as 60 dph. The genes mlc2a and mlc2b were expressed at various levels during the main phases of hyperplasia and hypertrophy. The genes myog and mlc2a were significantly up-regulated during the intensive stratified formation of new fibers and their expression was significantly correlated. Expression of mstn1 and igf1 increased at 35 dph, appeared to regulate the hyperplasia-to-hypertrophy transition, and may have stimulated the expression of mlc2a, mlc2b and col1a1 at the onset of mosaic hyperplasia. The up-regulation of mstn1 at transitional phases in muscle development indicates a dual regulatory role of myostatin in fish larval muscle growth.
Assuntos
Miosinas Cardíacas/genética , Regulação para Baixo/genética , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Cadeias Leves de Miosina/genética , Miostatina/genética , Dourada/genética , Regulação para Cima/genética , Animais , Miosinas Cardíacas/metabolismo , Análise por Conglomerados , Hipertrofia , Larva/genética , Larva/crescimento & desenvolvimento , Desenvolvimento Muscular/genética , Cadeias Leves de Miosina/metabolismo , Miostatina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Dourada/crescimento & desenvolvimento , Estatísticas não ParamétricasRESUMO
OBJECTIVE: To investigate epidermal growth factor, transforming growth factor-α and interleukin-8 production in nasal mucosa irrigated with hypertonic 2.3 per cent solution with algae extracts, in comparison to 0.9 per cent NaCl during the first two weeks after surgery for nasal polyposis, in relation to symptoms and local findings. METHODS: This prospective study included 20 nasal polyposis patients postoperatively irrigated with hypertonic solution and 20 nasal polyposis patients postoperatively irrigated with isotonic solution. We evaluated nasal symptom score, endoscopic score and mediator levels in nasal secretions before and after irrigation. RESULTS: Following treatment, nasal symptom score and endoscopic score were significantly lower in the hypertonic solution group (p = 0.023; p < 0.001, respectively). The increase in the epidermal growth factor and the decrease in the transforming growth factor-α and interleukin-8 concentration were higher in the hypertonic group (p < 0.001 for all mediators). CONCLUSION: Irrigation with a hypertonic solution was found to be more effective than an isotonic solution in nasal mucosa reparation.
Assuntos
Fator de Crescimento Epidérmico , Interleucina-8 , Lavagem Nasal , Mucosa Nasal , Pólipos Nasais , Água do Mar , Fator de Crescimento Transformador alfa , Humanos , Pólipos Nasais/cirurgia , Pólipos Nasais/metabolismo , Masculino , Feminino , Estudos Prospectivos , Interleucina-8/metabolismo , Interleucina-8/análise , Adulto , Pessoa de Meia-Idade , Mucosa Nasal/metabolismo , Mucosa Nasal/efeitos dos fármacos , Lavagem Nasal/métodos , Fator de Crescimento Epidérmico/análise , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Transformador alfa/metabolismo , Fator de Crescimento Transformador alfa/análise , Endoscopia/métodos , Soluções Hipertônicas , Idoso , Adulto JovemRESUMO
Argonaute 2 (AGO2) is an indispensable component of the RNA-induced silencing complex, operating at the translational or posttranscriptional level. It is compartmentalized into structures such as GW- and P-bodies, stress granules and adherens junctions as well as the midbody. Here we show using immunofluorescence, image and bioinformatic analysis and cytogenetics that AGO2 also resides in membrane protrusions such as open- and close-ended tubes. The latter are cytokinetic bridges where AGO2 colocalizes at the midbody arms with cytoskeletal components such as α-Τubulin and Aurora B, and various kinases. AGO2, phosphorylated on serine 387, is located together with Dicer at the midbody ring in a manner dependent on p38 MAPK activity. We further show that AGO2 is stress sensitive and important to ensure the proper chromosome segregation and cytokinetic fidelity. We suggest that AGO2 is part of a regulatory mechanism triggered by cytokinetic stress to generate the appropriate micro-environment for local transcript homeostasis.
Assuntos
Proteínas Argonautas/fisiologia , Divisão Celular , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Actinas/metabolismo , Proteínas Argonautas/metabolismo , Linhagem Celular , Citocinese , Citoesqueleto/metabolismo , Imunofluorescência , Células HCT116 , Células Hep G2 , Humanos , Pseudópodes/metabolismo , Tubulina (Proteína)/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologiaRESUMO
BACKGROUND: Myzus persicae nicotianae is an important pest in Greece, controlled mainly by neonicotinoids. Monitoring of the aphid populations for resistance mechanisms is essential for effective control. RESULTS: Two new RFLP-based diagnostics for the detection of the M918T (super-kdr pyrethroid resistance) and nAChR R81T (neonicotinoid resistance) mutations were applied, along with other established assays, on 131 nicotianae multilocus genotypes (MLGs) collected from tobacco and peach in Greece in 2012-2013. Furthermore, we present resistance data from aphid clones (>500, mainly nicotianae) collected in 2006-2007. About half of the clones tested with a diagnostic dose of imidacloprid were tolerant. The R81T mutation was not found in the 131 MLGs and 152 clones examined. Over half (58.6%) of a subset of 29 clones showed a 9-36-fold overexpression of CYP6CY3. M918T was found at low to moderate frequencies. The kdr and MACE mechanisms and carboxylesterase-based resistance were found at high frequency in all years. CONCLUSION: The aphid retains costly resistance mechanisms even in the absence of pressure from certain insecticides, which could be attributed to factors related to climate and genetic properties of the populations. The indication of build-up of resistance/tolerance to neonicotinoids, related to CYP6CY3 overexpression, is a matter of concern. © 2015 Society of Chemical Industry.