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1.
EMBO Rep ; 25(3): 1130-1155, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38291337

RESUMO

The correct establishment of DNA methylation patterns is vital for mammalian development and is achieved by the de novo DNA methyltransferases DNMT3A and DNMT3B. DNMT3B localises to H3K36me3 at actively transcribing gene bodies via its PWWP domain. It also functions at heterochromatin through an unknown recruitment mechanism. Here, we find that knockout of DNMT3B causes loss of methylation predominantly at H3K9me3-marked heterochromatin and that DNMT3B PWWP domain mutations or deletion result in striking increases of methylation in H3K9me3-marked heterochromatin. Removal of the N-terminal region of DNMT3B affects its ability to methylate H3K9me3-marked regions. This region of DNMT3B directly interacts with HP1α and facilitates the bridging of DNMT3B with H3K9me3-marked nucleosomes in vitro. Our results suggest that DNMT3B is recruited to H3K9me3-marked heterochromatin in a PWWP-independent manner that is facilitated by the protein's N-terminal region through an interaction with a key heterochromatin protein. More generally, we suggest that DNMT3B plays a role in DNA methylation homeostasis at heterochromatin, a process which is disrupted in cancer, aging and Immunodeficiency, Centromeric Instability and Facial Anomalies (ICF) syndrome.


Assuntos
Metilação de DNA , Face/anormalidades , Heterocromatina , Doenças da Imunodeficiência Primária , Animais , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Mutação , Mamíferos/genética , Mamíferos/metabolismo
2.
Genes Dev ; 30(19): 2158-2172, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27737959

RESUMO

Compaction of chromosomes is essential for accurate segregation of the genome during mitosis. In vertebrates, two condensin complexes ensure timely chromosome condensation, sister chromatid disentanglement, and maintenance of mitotic chromosome structure. Here, we report that biallelic mutations in NCAPD2, NCAPH, or NCAPD3, encoding subunits of these complexes, cause microcephaly. In addition, hypomorphic Ncaph2 mice have significantly reduced brain size, with frequent anaphase chromatin bridge formation observed in apical neural progenitors during neurogenesis. Such DNA bridges also arise in condensin-deficient patient cells, where they are the consequence of failed sister chromatid disentanglement during chromosome compaction. This results in chromosome segregation errors, leading to micronucleus formation and increased aneuploidy in daughter cells. These findings establish "condensinopathies" as microcephalic disorders, with decatenation failure as an additional disease mechanism for microcephaly, implicating mitotic chromosome condensation as a key process ensuring mammalian cerebral cortex size.


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Ligação a DNA/genética , Microcefalia/genética , Mitose/genética , Complexos Multiproteicos/genética , Mutação/genética , Aneuploidia , Animais , Catenanos/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Instabilidade Cromossômica/genética , Segregação de Cromossomos/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Micronúcleos com Defeito Cromossômico , Neurônios/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Células-Tronco
3.
Mol Cell ; 60(6): 873-85, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26687677

RESUMO

The Microprocessor complex (DGCR8/Drosha) is required for microRNA (miRNA) biogenesis but also binds and regulates the stability of several types of cellular RNAs. Of particular interest, DGCR8 controls the stability of mature small nucleolar RNA (snoRNA) transcripts independently of Drosha, suggesting the existence of alternative DGCR8 complex(es) with other nucleases to process a variety of cellular RNAs. Here, we found that DGCR8 copurifies with subunits of the nuclear exosome, preferentially associating with its hRRP6-containing nucleolar form. Importantly, we demonstrate that DGCR8 is essential for the recruitment of the exosome to snoRNAs and to human telomerase RNA. In addition, we show that the DGCR8/exosome complex controls the stability of the human telomerase RNA component (hTR/TERC). Altogether, these data suggest that DGCR8 acts as an adaptor to recruit the exosome complex to structured RNAs and induce their degradation.


Assuntos
Células-Tronco Embrionárias/citologia , Exorribonucleases/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , RNA de Cadeia Dupla/metabolismo , RNA de Transferência/química , Proteínas de Ligação a RNA/metabolismo , Animais , Células-Tronco Embrionárias/metabolismo , Exossomos/metabolismo , Células HEK293 , Células HeLa , Humanos , Camundongos , Estabilidade de RNA , RNA de Cadeia Dupla/química , RNA Nucleolar Pequeno/metabolismo , RNA de Transferência/metabolismo
4.
Haemophilia ; 28(3): 437-444, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35201650

RESUMO

BACKGROUND: Data are limited on prostate cancer (PC) management in patients with haemophilia (PWH). AIM: To describe PC screening and diagnosis, treatment modalities and bleeding complications in a group of unselected PWH followed at French Haemophilia Treatment Centres (HTCs) PATIENTS AND METHODS: PC screening, management and bleeding complications were retrospectively investigated at 14 French HTCs between 2003 and 2018. RESULTS: Among> 1549 > 50-year-old PWHs, 73 (4.7%) underwent PC screening (median age 71.1 years; 67/6 HA/HB, 17/56 severe-moderate/mild). At diagnosis, haematuria was infrequent. Prophylaxis was administered during 76/86 (88%) prostate biopsies (PB) (n = 67 clotting factor concentrates, CFC; n = 9 desmopressin; n = 17 associated with tranexamic acid, TA). Bleeding (11/86, 12.8%) occurred mainly post-prophylaxis (median delay: 7 days): haematuria (9/11, 81.8%), and rectal bleeding (2/11, 18.2%) including one major (1.2%). PC was confirmed in 50/86 PB and in two prostatectomy specimens (total n = 50 patients, n = 6 with only active surveillance). Surgery (n = 28/44 patients) was managed with CFC. Fifteen patients had radiotherapy/brachytherapy, 10 had hormone therapy; CFC-based prophylaxis was only prescribed for brachytherapy (n = 2). Major bleedings occurred in 3/28 (10.7%) and 2/15 (13.3%) patients who underwent surgery and radio/brachytherapy, respectively. No bleeding risk factor was found. CONCLUSION: Our data indicate that PB requires prophylaxis for atleast 7 days, using CFC, desmopressin or TA in function of haemophilia severity. PC surgery should be considered at high bleeding risk. Long-term post-procedural CFC or oral TA could be discussed. Radiotherapy/brachytherapy also should be managed with prophylaxis (CFC or TA).


Assuntos
Hemofilia A , Neoplasias da Próstata , Idoso , Biópsia , Desamino Arginina Vasopressina/uso terapêutico , Hematúria/complicações , Hemofilia A/complicações , Hemofilia A/tratamento farmacológico , Hemorragia/complicações , Hemorragia/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Próstata , Neoplasias da Próstata/complicações , Neoplasias da Próstata/terapia , Estudos Retrospectivos
5.
Eur J Anaesthesiol ; 39(3): 227-235, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34101713

RESUMO

BACKGROUND: Elective caesarean section is performed mainly under spinal anaesthesia using hyperbaric bupivacaine combined with opioids. Despite rapid onset, good quality anaesthesia, bupivacaine provides a long duration of motor block and is related to maternal hypotension. Current policies appeal for implementation of enhanced recovery procedures after caesarean section. Hyperbaric prilocaine is an intermediate-acting local anaesthetic known for its efficacy in ambulatory surgery. Evidence on the clinical relevance of intrathecal prilocaine use for caesarean section is currently lacking. OBJECTIVES: We aimed to investigate whether hyperbaric prilocaine would offer a shorter motor block and recovery than bupivacaine, when comparing equipotent doses. We also assessed the characteristics of sensory block, maternal haemodynamics and side effects for both mother and newborn. DESIGN: Prospective, randomised, double-blind, controlled, two-centre, clinical trial. SETTING: One university teaching hospital and one general teaching hospital in Brussels, Belgium. PATIENTS: American Society of Anesthesiologists' physical status 2 parturients (n = 40) undergoing caesarean section under spinal anaesthesia. INTERVENTIONS: Patients were randomly assigned to receive spinal anaesthesia using hyperbaric prilocaine 50 mg or hyperbaric bupivacaine 10 mg, both given with sufentanil 2.5 µg and morphine 100 µg. An epidural catheter was introduced as a backup in case of failure. MAIN OUTCOMES: The primary outcome was the motor block regression (modified Bromage scale 1 to 6). Secondary outcomes included sensory block characteristics, first unassisted ambulation, maternal side effects, newborns' parameters and overall satisfaction. RESULTS: Median [IQR] motor block was significantly shorter in the hyperbaric prilocaine group (110 [104 to 150] min versus 175 [135 to 189] min, P = 0.001). First unassisted ambulation was achieved earlier after prilocaine (204.5 [177 to 246.5] min versus 314 [209.25 to 400] min, P = 0.007), and the incidence of maternal hypotension was significantly higher with bupivacaine (P = 0.033). No supplementary epidural analgesia was needed. CONCLUSION: Prilocaine provides shorter motor block, faster recovery and better haemodynamic stability than bupivacaine while offering equivalent surgical anaesthesia. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02973048, EudraCT: 2016-003010-26.


Assuntos
Anestesia Obstétrica , Raquianestesia , Anestesia Obstétrica/efeitos adversos , Raquianestesia/efeitos adversos , Anestésicos Locais/efeitos adversos , Bupivacaína/efeitos adversos , Cesárea , Método Duplo-Cego , Feminino , Humanos , Recém-Nascido , Gravidez , Prilocaína , Estudos Prospectivos
6.
Platelets ; 32(5): 705-709, 2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-32627625

RESUMO

Acquired deficiencies in platelet glycoprotein VI are rare and have not been found associated with other defects. Here we report the case of a 64-year old male patient presenting an immune GPVI deficiency associated to a mutation in the alpha-actinin gene and who has been treated with dual anti platelet therapy without bleeding.Introduction: Glycoprotein (GP) VI, a pluripotent receptor interacting with collagen and fibrin(ogen) is responsible for thrombus formation, growth and stability (1-4). It is co-expressed with the Fc receptor γ (FcRγ) chain (5). GPVI is not critical for haemostasis since subjects with a GPVI deficiency usually present low or even no bleeding tendency (6, 7). Acquired GPVI deficiency due to antibody-induced GPVI depletion is the most frequent finding. At least 10 patients have been described with an acquired GPVI deficiency, most often associated to immune thrombocytopenia, moderate bleeding and impaired collagen-induced platelet aggregation (7). Several mechanisms leading to the GPVI deficiency are proposed including antibody-triggered GPVI internalization and/or shedding of the extracellular domain (8, 9). We report the case of a patient presenting an acquired GPVI deficiency different from those previously described: (i) he is male whereas all previous cases were female, (ii) he is heterozygous for a mutation in α (alpha)-actinin-1 gene and (iii) he was treated with dual antiplatelet therapy with no haemorrhagic manifestation.


Assuntos
Terapia Antiplaquetária Dupla/métodos , Hemorragia/tratamento farmacológico , Glicoproteínas da Membrana de Plaquetas/deficiência , Humanos , Masculino , Pessoa de Meia-Idade
9.
Br J Anaesth ; 123(3): 269-287, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31351590

RESUMO

BACKGROUND: Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes. METHODS: The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, infectious, and bleeding complications. Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations. RESULTS: The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87. CONCLUSIONS: Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation. RECOMMENDATION: neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty. TRIAL REGISTRY NUMBER: PROSPERO CRD42018099935.


Assuntos
Anestesia Epidural/efeitos adversos , Anestesia Geral/efeitos adversos , Raquianestesia/efeitos adversos , Artroplastia de Quadril/métodos , Artroplastia do Joelho/métodos , Anestesia Epidural/mortalidade , Anestesia Geral/mortalidade , Raquianestesia/mortalidade , Artroplastia de Quadril/mortalidade , Artroplastia do Joelho/mortalidade , Medicina Baseada em Evidências/métodos , Humanos , Complicações Pós-Operatórias/mortalidade , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
10.
Blood ; 125(3): 553-61, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25320241

RESUMO

We conducted a multicenter study of 101 patients with congenital dysfibrinogenemia (CD) to characterize the incidence of hemorrhagic and thrombotic events as well as complications of pregnancy and surgery. At the time of diagnosis, 10.9% and 13.9% had experienced major bleeding and thrombotic events, respectively. During a mean follow-up of 8.8 years after CD diagnosis, the incidence of major bleeding and thrombotic events was 2.5 and 18.7 per 1000 patient-years, respectively, with estimated cumulative incidences at age 50 years of 19.2% and 30.1%. We identified 111 pregnancies with an overall incidence of spontaneous abortions and postpartum hemorrhage of 19.8% and 21.4%, respectively. The risk of postpartum hemorrhage was associated with a previously identified bleeding phenotype (odds ratio, 5.8; 95% CI, 1.2 to 28.0). Among 137 surgical procedures analyzed, 9 (6.5%) were complicated by abnormal bleeding. Propositi vs relatives, sex, mutation hotspots, fibrinogen levels, and activity:antigen ratios were not associated with the risk of thrombotic or bleeding outcomes. In conclusion, the results of our study, the largest in genotyped CD and the first including long-term history, indicate that propositi with CD and their relatives carry not only a high risk of major bleeding, including postpartum hemorrhage, but also of thrombotic event.


Assuntos
Aborto Espontâneo/epidemiologia , Afibrinogenemia/complicações , Hemorragia/epidemiologia , Complicações Hematológicas na Gravidez/epidemiologia , Trombose/epidemiologia , Aborto Espontâneo/etiologia , Adolescente , Adulto , Afibrinogenemia/cirurgia , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Hemorragia/etiologia , Humanos , Incidência , Masculino , Complicações Pós-Operatórias , Gravidez , Complicações Hematológicas na Gravidez/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Trombose/etiologia , Adulto Jovem
11.
PLoS Genet ; 10(9): e1004577, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25232951

RESUMO

Cilia are highly conserved microtubule-based structures that perform a variety of sensory and motility functions during development and adult homeostasis. In humans, defects specifically affecting motile cilia lead to chronic airway infections, infertility and laterality defects in the genetically heterogeneous disorder Primary Ciliary Dyskinesia (PCD). Using the comparatively simple Drosophila system, in which mechanosensory neurons possess modified motile cilia, we employed a recently elucidated cilia transcriptional RFX-FOX code to identify novel PCD candidate genes. Here, we report characterization of CG31320/HEATR2, which plays a conserved critical role in forming the axonemal dynein arms required for ciliary motility in both flies and humans. Inner and outer arm dyneins are absent from axonemes of CG31320 mutant flies and from PCD individuals with a novel splice-acceptor HEATR2 mutation. Functional conservation of closely arranged RFX-FOX binding sites upstream of HEATR2 orthologues may drive higher cytoplasmic expression of HEATR2 during early motile ciliogenesis. Immunoprecipitation reveals HEATR2 interacts with DNAI2, but not HSP70 or HSP90, distinguishing it from the client/chaperone functions described for other cytoplasmic proteins required for dynein arm assembly such as DNAAF1-4. These data implicate CG31320/HEATR2 in a growing intracellular pre-assembly and transport network that is necessary to deliver functional dynein machinery to the ciliary compartment for integration into the motile axoneme.


Assuntos
Cílios/metabolismo , Cílios/fisiologia , Proteínas/metabolismo , Animais , Dineínas do Axonema , Axonema/genética , Axonema/metabolismo , Sítios de Ligação/genética , Linhagem Celular , Pré-Escolar , Cílios/genética , Transtornos da Motilidade Ciliar/genética , Transtornos da Motilidade Ciliar/metabolismo , Drosophila/genética , Drosophila/metabolismo , Dineínas/genética , Dineínas/metabolismo , Feminino , Humanos , Síndrome de Kartagener/genética , Síndrome de Kartagener/metabolismo , Masculino , Mutação/genética , Linhagem , Fenótipo , Proteínas/genética , Transcrição Gênica/genética
12.
Hum Mol Genet ; 23(10): 2569-79, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24363063

RESUMO

Heterozygous loss-of-function (LOF) mutations in the gene encoding the DNA-binding protein, SATB2, result in micrognathia and cleft palate in both humans and mice. In three unrelated individuals, we show that translocation breakpoints (BPs) up to 896 kb 3' of SATB2 polyadenylation site cause a phenotype which is indistinguishable from that caused by SATB2 LOF mutations. This syndrome comprises long nose, small mouth, micrognathia, cleft palate, arachnodactyly and intellectual disability. These BPs map to a gene desert between PLCL1 and SATB2. We identified three putative cis-regulatory elements (CRE1-3) using a comparative genomic approach each of which would be placed in trans relative to SATB2 by all three BPs. CRE1-3 each bind p300 and mono-methylated H3K4 consistent with enhancer function. In silico analysis suggested that CRE1-3 contain one or more conserved SOX9-binding sites, and this binding was confirmed using chromatin immunoprecipitation on cells derived from mouse embryonic pharyngeal arch. Interphase bacterial artificial chromosome fluorescence in situ hybridization measurements in embryonic craniofacial tissues showed that the orthologous region in mice exhibits Satb2 expression-dependent chromatin decondensation consistent with Satb2 being a target gene of CRE1-3. To assess their in vivo function, we made multiple stable reporter transgenic lines for each enhancer in zebrafish. CRE2 was shown to drive SATB2-like expression in the embryonic craniofacial region. This expression could be eliminated by mutating the SOX9-binding site of CRE2. These observations suggest that SATB2 and SOX9 may be acting together via complex cis-regulation to coordinate the growth of the developing jaw.


Assuntos
Proteínas de Ligação à Região de Interação com a Matriz/genética , Síndrome de Pierre Robin/diagnóstico , Fatores de Transcrição SOX9/genética , Fatores de Transcrição/genética , Adulto , Animais , Sítios de Ligação , Células Cultivadas , Criança , Pré-Escolar , Epistasia Genética , Feminino , Humanos , Lactente , Masculino , Camundongos , Mutação , Síndrome de Pierre Robin/genética , Elementos Reguladores de Transcrição , Adulto Jovem , Peixe-Zebra
13.
Anesth Analg ; 122(1): 279-82, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26678473

RESUMO

BACKGROUND: The analgesic efficacy reported for the adductor canal block may be related to the spread of local anesthetic outside the adductor canal. METHODS: Fifteen patients undergoing knee surgery received ultrasound-guided injections of local anesthetic at the level of the adductor hiatus. Sensory-motor block and spread of contrast solution were assessed. RESULTS: Sensation was rated as "markedly diminished" or "absent" in the saphenous nerve distribution and "slightly diminished" in the sciatic nerve territory without motor deficits. Contrast solution was found in the popliteal fossa. CONCLUSIONS: The spread of injectate to the popliteal fossa may contribute to the analgesic efficacy of adductor canal block.


Assuntos
Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacocinética , Articulação do Joelho/inervação , Mepivacaína/administração & dosagem , Mepivacaína/farmacocinética , Atividade Motora/efeitos dos fármacos , Bloqueio Nervoso/métodos , Limiar da Dor/efeitos dos fármacos , Adulto , Anestésicos Locais/efeitos adversos , Bélgica , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Masculino , Mepivacaína/efeitos adversos , Pessoa de Meia-Idade , Bloqueio Nervoso/efeitos adversos , Distribuição Tecidual , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia de Intervenção
14.
Anesth Analg ; 123(2): 501-3, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27442773

RESUMO

The adductor canal block has become a common analgesic technique in patients undergoing knee arthroplasty. Dispersion of local anesthetic outside the adductor canal through interfascial layers and blockade of smaller nerves that confer innervation to the knee could contribute to the analgesic efficacy of the adductor canal block. We studied the diffusion of local anesthetic mixed with dye after injection into the adductor canal in fresh human cadavers. In all 8 legs, injectate was found in the popliteal fossa in contact with the sciatic nerve and/or popliteal blood vessels. Interfascial spread patterns were identified.


Assuntos
Anestésicos Locais/administração & dosagem , Joelho/inervação , Bloqueio Nervoso/métodos , Nervo Isquiático/anatomia & histologia , Pontos de Referência Anatômicos , Cadáver , Corantes/administração & dosagem , Difusão , Humanos , Injeções , Joelho/cirurgia , Azul de Metileno/administração & dosagem
15.
PLoS Genet ; 9(1): e1003177, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23359656

RESUMO

Pax6 is a developmental control gene essential for eye development throughout the animal kingdom. In addition, Pax6 plays key roles in other parts of the CNS, olfactory system, and pancreas. In mammals a single Pax6 gene encoding multiple isoforms delivers these pleiotropic functions. Here we provide evidence that the genomes of many other vertebrate species contain multiple Pax6 loci. We sequenced Pax6-containing BACs from the cartilaginous elephant shark (Callorhinchus milii) and found two distinct Pax6 loci. Pax6.1 is highly similar to mammalian Pax6, while Pax6.2 encodes a paired-less Pax6. Using synteny relationships, we identify homologs of this novel paired-less Pax6.2 gene in lizard and in frog, as well as in zebrafish and in other teleosts. In zebrafish two full-length Pax6 duplicates were known previously, originating from the fish-specific genome duplication (FSGD) and expressed in divergent patterns due to paralog-specific loss of cis-elements. We show that teleosts other than zebrafish also maintain duplicate full-length Pax6 loci, but differences in gene and regulatory domain structure suggest that these Pax6 paralogs originate from a more ancient duplication event and are hence renamed as Pax6.3. Sequence comparisons between mammalian and elephant shark Pax6.1 loci highlight the presence of short- and long-range conserved noncoding elements (CNEs). Functional analysis demonstrates the ancient role of long-range enhancers for Pax6 transcription. We show that the paired-less Pax6.2 ortholog in zebrafish is expressed specifically in the developing retina. Transgenic analysis of elephant shark and zebrafish Pax6.2 CNEs with homology to the mouse NRE/Pα internal promoter revealed highly specific retinal expression. Finally, morpholino depletion of zebrafish Pax6.2 resulted in a "small eye" phenotype, supporting a role in retinal development. In summary, our study reveals that the pleiotropic functions of Pax6 in vertebrates are served by a divergent family of Pax6 genes, forged by ancient duplication events and by independent, lineage-specific gene losses.


Assuntos
Proteínas do Olho/genética , Duplicação Gênica , Proteínas de Homeodomínio/genética , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/genética , Tubarões/genética , Peixe-Zebra , Animais , Evolução Molecular , Proteínas do Olho/metabolismo , Regulação da Expressão Gênica , Variação Genética , Genoma , Proteínas de Homeodomínio/metabolismo , Camundongos , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/metabolismo , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Retina/metabolismo , Análise de Sequência de DNA , Vertebrados/genética , Vertebrados/crescimento & desenvolvimento , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento
16.
Dev Biol ; 387(2): 214-28, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24440152

RESUMO

Biological differences between cell types and developmental processes are characterised by differences in gene expression profiles. Gene-distal enhancers are key components of the regulatory networks that specify the tissue-specific expression patterns driving embryonic development and cell fate decisions, and variations in their sequences are a major contributor to genetic disease and disease susceptibility. Despite advances in the methods for discovery of putative cis-regulatory sequences, characterisation of their spatio-temporal enhancer activities in a mammalian model system remains a major bottle-neck. We employed a strategy that combines gnathostome sequence conservation with transgenic mouse and zebrafish reporter assays to survey the genomic locus of the developmental control gene PAX6 for the presence of novel cis-regulatory elements. Sequence comparison between human and the cartilaginous elephant shark (Callorhinchus milii) revealed several ancient gnathostome conserved non-coding elements (agCNEs) dispersed widely throughout the PAX6 locus, extending the range of the known PAX6 cis-regulatory landscape to contain the full upstream PAX6-RCN1 intergenic region. Our data indicates that ancient conserved regulatory sequences can be tested effectively in transgenic zebrafish even when not conserved in zebrafish themselves. The strategy also allows efficient dissection of compound regulatory regions previously assessed in transgenic mice. Remarkable overlap in expression patterns driven by sets of agCNEs indicates that PAX6 resides in a landscape of multiple tissue-specific regulatory archipelagos.


Assuntos
Elementos Facilitadores Genéticos/genética , Proteínas do Olho/genética , Olho/embriologia , Proteínas de Homeodomínio/genética , Fatores de Transcrição Box Pareados/genética , RNA não Traduzido/genética , Sequências Reguladoras de Ácido Nucleico/genética , Proteínas Repressoras/genética , Animais , Animais Geneticamente Modificados , Sequência de Bases , Linhagem Celular , Galinhas/genética , Sequência Conservada/genética , Olho/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes Controladores do Desenvolvimento/genética , Humanos , Camundongos , Gambás/genética , Fator de Transcrição PAX6 , Regiões Promotoras Genéticas , Análise de Sequência de DNA , Tubarões/genética , Vertebrados/genética , Xenopus/genética , Peixe-Zebra/genética
17.
J Clin Microbiol ; 53(3): 1034-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25568436
18.
Anesth Analg ; 120(5): 1138-1141, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25742631

RESUMO

BACKGROUND: We measured the spread of radiocontrast in the interscalene space after injection under low (<15 psi) and high (>20 psi) pressures. METHODS: Nine healthy volunteers received ultrasound-guided injections of 10 mL radio-opaque NaCl 0.9% in both interscalene spaces. Spread of injectate as assessed by computed tomography scan and discomfort on injection were recorded. RESULTS: Under both opening pressure conditions, injectate contacted 3 brachial plexus roots and spilled over the surface of the anterior and/or middle scalene muscles underneath the cervical fascia. CONCLUSIONS: Regardless of injection pressure, the interscalene space was filled with 10 mL of radiocontrast injectate.


Assuntos
Bloqueio do Plexo Braquial , Plexo Braquial/diagnóstico por imagem , Meios de Contraste/farmacocinética , Músculo Esquelético/diagnóstico por imagem , Cloreto de Sódio/farmacocinética , Tomografia Computadorizada por Raios X , Adulto , Bélgica , Meios de Contraste/administração & dosagem , Feminino , Voluntários Saudáveis , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Pressão , Cloreto de Sódio/administração & dosagem , Ultrassonografia de Intervenção
19.
Anaerobe ; 35(Pt B): 68-71, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26204794

RESUMO

Capnocytophaga spp. are commensal bacteria involved in oral and systemic diseases, with a variable susceptibility to beta-lactams. The cfxA gene expression level was assessed using quantitative RT-PCR, and reasons of the observed misexpression were discussed, as insertion of foreign genetic material, contributing to dissemination and evolution of antibiotic resistance genes.


Assuntos
Capnocytophaga/enzimologia , Infecções por Bactérias Gram-Negativas/microbiologia , Mucosa Bucal/microbiologia , beta-Lactamases/biossíntese , Antibacterianos/farmacologia , Capnocytophaga/efeitos dos fármacos , Capnocytophaga/genética , Capnocytophaga/isolamento & purificação , Perfilação da Expressão Gênica , Humanos , Testes de Sensibilidade Microbiana , Mutagênese Insercional , Reação em Cadeia da Polimerase em Tempo Real , Recombinação Genética , beta-Lactamases/genética , beta-Lactamas/farmacologia
20.
Proc Natl Acad Sci U S A ; 108(19): 7844-9, 2011 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-21518916

RESUMO

Translational control of many mRNAs in developing metazoan embryos is achieved by alterations in their poly(A) tail length. A family of cytoplasmic poly(A)-binding proteins (PABPs) bind the poly(A) tail and can regulate mRNA translation and stability. However, despite the extensive biochemical characterization of one family member (PABP1), surprisingly little is known about their in vivo roles or functional relatedness. Because no information is available in vertebrates, we address their biological roles, establishing that each of the cytoplasmic PABPs conserved in Xenopus laevis [PABP1, embryonic PABP (ePABP), and PABP4] is essential for normal development. Morpholino-mediated knockdown of PABP1 or ePABP causes both anterior and posterior phenotypes and embryonic lethality. In contrast, depletion of PABP4 results mainly in anterior defects and lethality at later stages. Unexpectedly, cross-rescue experiments reveal that neither ePABP nor PABP4 can fully rescue PABP1 depletion, establishing that PABPs have distinct functions. Comparative analysis of the uncharacterized PABP4 with PABP1 and ePABP shows that it shares a mechanistically conserved core role in promoting global translation. Consistent with this analysis, each morphant displays protein synthesis defects, suggesting that their roles in mRNA-specific translational regulation and/or mRNA decay, rather than global translation, underlie the functional differences between PABPs. Domain-swap experiments reveal that the basis of the functional specificity is complex, involving multiple domains of PABPs, and is conferred, at least in part, by protein-protein interactions.


Assuntos
Proteínas de Ligação a Poli(A)/metabolismo , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/metabolismo , Animais , Sequência de Bases , Feminino , Masculino , Oligodesoxirribonucleotídeos Antissenso/administração & dosagem , Oligodesoxirribonucleotídeos Antissenso/genética , Proteína I de Ligação a Poli(A)/antagonistas & inibidores , Proteína I de Ligação a Poli(A)/genética , Proteína I de Ligação a Poli(A)/metabolismo , Proteínas de Ligação a Poli(A)/antagonistas & inibidores , Proteínas de Ligação a Poli(A)/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Vertebrados/embriologia , Vertebrados/genética , Vertebrados/metabolismo , Proteínas de Xenopus/antagonistas & inibidores , Proteínas de Xenopus/genética , Xenopus laevis/genética
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