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1.
Int J Clin Pharmacol Ther ; 57(10): 483-488, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31426904

RESUMO

AIM: The aim of this study was to investigate the potential association between antihypertensive therapy and the incidence of Parkinson's disease (PD) in patients followed in general practices in Germany. MATERIALS AND METHODS: This study included patients aged ≥ 40 who had received initial diagnoses of PD in 1,203 general practices in Germany between January 2013 and December 2017 (index date). After applying similar inclusion criteria, PD cases were matched to non-PD controls using propensity scores based on age, sex, and treating physician. The primary outcome of the study was the incidence of PD as a function of the use of antihypertensive drugs (diuretics, ß-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers). Logistic regression models were conducted to study the association between the use of antihypertensive drugs and the incidence of PD after adjusting for codiagnoses and antihypertensive cotherapy. RESULTS: The present study included 9,127 patients with PD and 9,127 patients without PD (mean age: 75.8 years; 48.4% women). The at-least-once use of diuretics (44.8% versus 38.4%; odds ratio (OR) = 1.23 (1.15-1.32)) was associated with an increased incidence of PD. However, this effect was not maintained for a therapy duration of at least 3 years, and no association was observed between the diuretic therapy duration and PD incidence. For all other antihypertensive drug classes, we found no significant associations with PD incidence. CONCLUSION: No association was found between antihypertensive therapy duration and PD incidence. Further epidemiological studies are needed to compare the effects of subclasses of antihypertensives on PD.


Assuntos
Anti-Hipertensivos/efeitos adversos , Hipertensão/tratamento farmacológico , Doença de Parkinson/complicações , Antagonistas Adrenérgicos beta/efeitos adversos , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Antagonistas de Receptores de Angiotensina/efeitos adversos , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Bloqueadores dos Canais de Cálcio/efeitos adversos , Bloqueadores dos Canais de Cálcio/uso terapêutico , Diuréticos/efeitos adversos , Diuréticos/uso terapêutico , Feminino , Medicina Geral , Alemanha , Humanos , Hipertensão/complicações , Incidência , Masculino
2.
EMBO Rep ; 18(11): 2004-2014, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29051200

RESUMO

N6-methyladenosine (m6A) is a highly dynamic RNA modification that has recently emerged as a key regulator of gene expression. While many m6A modifications are installed by the METTL3-METTL14 complex, others appear to be introduced independently, implying that additional human m6A methyltransferases remain to be identified. Using crosslinking and analysis of cDNA (CRAC), we reveal that the putative human m6A "writer" protein METTL16 binds to the U6 snRNA and other ncRNAs as well as numerous lncRNAs and pre-mRNAs. We demonstrate that METTL16 is responsible for N6-methylation of A43 of the U6 snRNA and identify the early U6 biogenesis factors La, LARP7 and the methylphosphate capping enzyme MEPCE as METTL16 interaction partners. Interestingly, A43 lies within an essential ACAGAGA box of U6 that base pairs with 5' splice sites of pre-mRNAs during splicing, suggesting that METTL16-mediated modification of this site plays an important role in splicing regulation. The identification of METTL16 as an active m6A methyltransferase in human cells expands our understanding of the mechanisms by which the m6A landscape is installed on cellular RNAs.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/genética , Precursores de RNA/genética , Processamento de RNA , RNA Longo não Codificante/metabolismo , RNA Nuclear Pequeno/metabolismo , Adenosina/metabolismo , Pareamento de Bases , Sequência de Bases , DNA Complementar/genética , DNA Complementar/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HeLa , Humanos , Metilação , Metiltransferases/metabolismo , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Precursores de RNA/metabolismo , RNA Longo não Codificante/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Nuclear Pequeno/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo
3.
RNA Biol ; 14(9): 1138-1152, 2017 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27911188

RESUMO

rRNAs are extensively modified during their transcription and subsequent maturation in the nucleolus, nucleus and cytoplasm. RNA modifications, which are installed either by snoRNA-guided or by stand-alone enzymes, generally stabilize the structure of the ribosome. However, they also cluster at functionally important sites of the ribosome, such as the peptidyltransferase center and the decoding site, where they facilitate efficient and accurate protein synthesis. The recent identification of sites of substoichiometric 2'-O-methylation and pseudouridylation has overturned the notion that all rRNA modifications are constitutively present on ribosomes, highlighting nucleotide modifications as an important source of ribosomal heterogeneity. While the mechanisms regulating partial modification and the functions of specialized ribosomes are largely unknown, changes in the rRNA modification pattern have been observed in response to environmental changes, during development, and in disease. This suggests that rRNA modifications may contribute to the translational control of gene expression.


Assuntos
Células Eucarióticas/fisiologia , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , Ribossomos/metabolismo , Acetilação , Animais , Suscetibilidade a Doenças , Humanos , Metilação , RNA Ribossômico/química , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Ribossomos/química , Relação Estrutura-Atividade
4.
Hum Mol Genet ; 25(24): 5353-5364, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27798105

RESUMO

Bowen-Conradi syndrome (BCS) is a severe genetic disorder that is characterised by various developmental abnormalities, bone marrow failure and early infant death. This disease is caused by a single mutation leading to the aspartate 86 to glycine (D86G) exchange in the essential nucleolar RNA methyltransferase EMG1. EMG1 is required for the synthesis of the small ribosomal subunit and is involved in modification of the 18S ribosomal RNA. Here, we identify the pre-ribosomal factors NOP14, NOC4L and UTP14A as members of a nucleolar subcomplex that contains EMG1 and is required for its recruitment to nucleoli. The BCS mutation in EMG1 leads to reduced nucleolar localisation, accumulation of EMG1D86G in nuclear foci and its proteasome-dependent degradation. We further show that EMG1 can be imported into the nucleus by the importins (Imp) Impα/ß or Impß/7. Interestingly, in addition to its role in nuclear import, binding of the Impß/7 heterodimer can prevent unspecific aggregation of both EMG1 and EMG1D86G on RNAs in vitro, indicating that the importins act as chaperones by binding to basic regions of the RNA methyltransferase. Our findings further indicate that in BCS, nuclear disassembly of the import complex and release of EMG1D86G lead to its nuclear aggregation and degradation, resulting in the reduced nucleolar recruitment of the RNA methyltransferase and defects in the biogenesis of the small ribosomal subunit.


Assuntos
Transporte Ativo do Núcleo Celular/genética , Retardo do Crescimento Fetal/genética , Metiltransferases/genética , Proteínas Nucleares/genética , Transtornos Psicomotores/genética , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Retardo do Crescimento Fetal/patologia , Células HeLa , Humanos , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Mutação/genética , Proteínas Nucleares/metabolismo , Ligação Proteica , Transtornos Psicomotores/patologia , RNA Ribossômico 18S/genética , beta Carioferinas/genética , beta Carioferinas/metabolismo
5.
EMBO J ; 35(19): 2104-2119, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27497299

RESUMO

Mitochondrial gene expression uses a non-universal genetic code in mammals. Besides reading the conventional AUG codon, mitochondrial (mt-)tRNAMet mediates incorporation of methionine on AUA and AUU codons during translation initiation and on AUA codons during elongation. We show that the RNA methyltransferase NSUN3 localises to mitochondria and interacts with mt-tRNAMet to methylate cytosine 34 (C34) at the wobble position. NSUN3 specifically recognises the anticodon stem loop (ASL) of the tRNA, explaining why a mutation that compromises ASL basepairing leads to disease. We further identify ALKBH1/ABH1 as the dioxygenase responsible for oxidising m5C34 of mt-tRNAMet to generate an f5C34 modification. In vitro codon recognition studies with mitochondrial translation factors reveal preferential utilisation of m5C34 mt-tRNAMet in initiation. Depletion of either NSUN3 or ABH1 strongly affects mitochondrial translation in human cells, implying that modifications generated by both enzymes are necessary for mt-tRNAMet function. Together, our data reveal how modifications in mt-tRNAMet are generated by the sequential action of NSUN3 and ABH1, allowing the single mitochondrial tRNAMet to recognise the different codons encoding methionine.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Códon/metabolismo , Proteínas de Membrana/metabolismo , Metiltransferases/metabolismo , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Biossíntese de Proteínas , RNA de Transferência de Metionina/metabolismo , Animais , Humanos , Mamíferos , Análise de Sequência de DNA
6.
RNA ; 21(9): 1532-43, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26160102

RESUMO

Many cellular RNAs require modification of specific residues for their biogenesis, structure, and function. 5-methylcytosine (m(5)C) is a common chemical modification in DNA and RNA but in contrast to the DNA modifying enzymes, only little is known about the methyltransferases that establish m(5)C modifications in RNA. The putative RNA methyltransferase NSUN6 belongs to the family of Nol1/Nop2/SUN domain (NSUN) proteins, but so far its cellular function has remained unknown. To reveal the target spectrum of human NSUN6, we applied UV crosslinking and analysis of cDNA (CRAC) as well as chemical crosslinking with 5-azacytidine. We found that human NSUN6 is associated with tRNAs and acts as a tRNA methyltransferase. Furthermore, we uncovered tRNA(Cys) and tRNA(Thr) as RNA substrates of NSUN6 and identified the cytosine C72 at the 3' end of the tRNA acceptor stem as the target nucleoside. Interestingly, target recognition in vitro depends on the presence of the 3'-CCA tail. Together with the finding that NSUN6 localizes to the cytoplasm and largely colocalizes with marker proteins for the Golgi apparatus and pericentriolar matrix, our data suggest that NSUN6 modifies tRNAs in a late step in their biogenesis.


Assuntos
5-Metilcitosina/metabolismo , Citoplasma/metabolismo , RNA de Transferência/metabolismo , tRNA Metiltransferases/genética , tRNA Metiltransferases/metabolismo , Azacitidina/farmacologia , Reagentes para Ligações Cruzadas , Inibidores Enzimáticos/farmacologia , Complexo de Golgi/metabolismo , Células HEK293 , Células HeLa , Humanos , Técnicas In Vitro , Metilação , RNA de Transferência/química
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