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1.
Nat Immunol ; 20(11): 1517-1529, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31591571

RESUMO

The establishment of a diverse B cell antigen receptor (BCR) repertoire by V(D)J recombination also generates autoreactive B cells. Anergy is one tolerance mechanism; it renders autoreactive B cells insensitive to stimulation by self-antigen, whereas Toll-like receptor (TLR) signaling can reactivate anergic B cells. Here, we describe a critical role of the transcription factor Ikaros in controlling BCR anergy and TLR signaling. Mice with specific deletion of Ikaros in mature B cells developed systemic autoimmunity. Ikaros regulated many anergy-associated genes, including Zfp318, which is implicated in the attenuation of BCR responsiveness by promoting immunoglobulin D expression in anergic B cells. TLR signaling was hyperactive in Ikaros-deficient B cells, which failed to upregulate feedback inhibitors of the MyD88-nuclear factor κB signaling pathway. Systemic inflammation was lost on expression of a non-self-reactive BCR or loss of MyD88 in Ikaros-deficient B cells. Thus, Ikaros acts as a guardian preventing autoimmunity by promoting BCR anergy and restraining TLR signaling.


Assuntos
Autoimunidade/genética , Linfócitos B/imunologia , Anergia Clonal/genética , Fator de Transcrição Ikaros/metabolismo , Receptores Toll-Like/metabolismo , Animais , Linfócitos B/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/imunologia , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Imunoglobulina D/imunologia , Imunoglobulina D/metabolismo , Camundongos , Modelos Animais , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptores Toll-Like/imunologia
2.
Nat Immunol ; 17(3): 331-43, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26779602

RESUMO

The transcription factor Blimp-1 is necessary for the generation of plasma cells. Here we studied its functions in plasmablast differentiation by identifying regulated Blimp-1 target genes. Blimp-1 promoted the migration and adhesion of plasmablasts. It directly repressed genes encoding several transcription factors and Aicda (which encodes the cytidine deaminase AID) and thus silenced B cell-specific gene expression, antigen presentation and class-switch recombination in plasmablasts. It directly activated genes, which led to increased expression of the plasma cell regulator IRF4 and proteins involved in immunoglobulin secretion. Blimp-1 induced the transcription of immunoglobulin genes by controlling the 3' enhancers of the loci encoding the immunoglobulin heavy chain (Igh) and κ-light chain (Igk) and, furthermore, regulated the post-transcriptional expression switch from the membrane-bound form of the immunoglobulin heavy chain to its secreted form by activating Ell2 (which encodes the transcription-elongation factor ELL2). Notably, Blimp-1 recruited chromatin-remodeling and histone-modifying complexes to regulate its target genes. Hence, many essential functions of plasma cells are under the control of Blimp-1.


Assuntos
Diferenciação Celular/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias kappa de Imunoglobulina/imunologia , Fatores Reguladores de Interferon/imunologia , Plasmócitos/imunologia , Fatores de Transcrição/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Adesão Celular/genética , Adesão Celular/imunologia , Diferenciação Celular/genética , Ensaios de Migração de Leucócitos , Movimento Celular/genética , Movimento Celular/imunologia , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Regulação da Expressão Gênica , Células HEK293 , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias kappa de Imunoglobulina/genética , Fatores Reguladores de Interferon/genética , Espectrometria de Massas , Camundongos , Plasmócitos/metabolismo , Fator 1 de Ligação ao Domínio I Regulador Positivo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Análise de Sequência de RNA , Fatores de Transcrição/genética
3.
EMBO J ; 41(7): e108397, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35156727

RESUMO

While PAX5 is an important tumor suppressor gene in B-cell acute lymphoblastic leukemia (B-ALL), it is also involved in oncogenic translocations coding for diverse PAX5 fusion proteins. PAX5-JAK2 encodes a protein consisting of the PAX5 DNA-binding region fused to the constitutively active JAK2 kinase domain. Here, we studied the oncogenic function of the PAX5-JAK2 fusion protein in a mouse model expressing it from the endogenous Pax5 locus, resulting in inactivation of one of the two Pax5 alleles. Pax5Jak2/+ mice rapidly developed an aggressive B-ALL in the absence of another cooperating exogenous gene mutation. The DNA-binding function and kinase activity of Pax5-Jak2 as well as IL-7 signaling contributed to leukemia development. Interestingly, all Pax5Jak2/+ tumors lost the remaining wild-type Pax5 allele, allowing efficient DNA-binding of Pax5-Jak2. While we could not find evidence for a nuclear role of Pax5-Jak2 as an epigenetic regulator, high levels of active phosphorylated STAT5 and increased expression of STAT5 target genes were seen in Pax5Jak2/+ B-ALL tumors, implying that nuclear Pax5-Jak2 phosphorylates STAT5. Together, these data reveal Pax5-Jak2 as an important nuclear driver of leukemogenesis by maintaining phosphorylated STAT5 levels in the nucleus.


Assuntos
Janus Quinase 2 , Leucemia de Células B , Fator de Transcrição PAX5 , Fator de Transcrição STAT5 , Animais , Janus Quinase 2/genética , Leucemia de Células B/genética , Camundongos , Mutação , Fator de Transcrição PAX5/genética , Fator de Transcrição STAT5/genética , Translocação Genética
4.
Nature ; 584(7819): 142-147, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32612238

RESUMO

Nuclear processes, such as V(D)J recombination, are orchestrated by the three-dimensional organization of chromosomes at multiple levels, including compartments1 and topologically associated domains (TADs)2,3 consisting of chromatin loops4. TADs are formed by chromatin-loop extrusion5-7, which depends on the loop-extrusion function of the ring-shaped cohesin complex8-12. Conversely, the cohesin-release factor Wapl13,14 restricts loop extension10,15. The generation of a diverse antibody repertoire, providing humoral immunity to pathogens, requires the participation of all V genes in V(D)J recombination16, which depends on contraction of the 2.8-Mb-long immunoglobulin heavy chain (Igh) locus by Pax517,18. However, how Pax5 controls Igh contraction in pro-B cells remains unknown. Here we demonstrate that locus contraction is caused by loop extrusion across the entire Igh locus. Notably, the expression of Wapl is repressed by Pax5 specifically in pro-B and pre-B cells, facilitating extended loop extrusion by increasing the residence time of cohesin on chromatin. Pax5 mediates the transcriptional repression of Wapl through a single Pax5-binding site by recruiting the polycomb repressive complex 2 to induce bivalent chromatin at the Wapl promoter. Reduced Wapl expression causes global alterations in the chromosome architecture, indicating that the potential to recombine all V genes entails structural changes of the entire genome in pro-B cells.


Assuntos
Genes de Cadeia Pesada de Imunoglobulina/genética , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Fator de Transcrição PAX5/metabolismo , Proteínas/genética , Proteínas Repressoras/metabolismo , Recombinação V(D)J/genética , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/metabolismo , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Cadeias Pesadas de Imunoglobulinas/química , Região Variável de Imunoglobulina/química , Camundongos , Complexo Repressor Polycomb 2/metabolismo , Células Precursoras de Linfócitos B/citologia , Células Precursoras de Linfócitos B/metabolismo , Regiões Promotoras Genéticas/genética , Coesinas
5.
Immunity ; 44(3): 698-711, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26982367

RESUMO

Microsatellite instability in colorectal cancer predicts favorable outcomes. However, the mechanistic relationship between microsatellite instability, tumor-infiltrating immune cells, Immunoscore, and their impact on patient survival remains to be elucidated. We found significant differences in mutational patterns, chromosomal instability, and gene expression that correlated with patient microsatellite instability status. A prominent immune gene expression was observed in microsatellite-instable (MSI) tumors, as well as in a subgroup of microsatellite-stable (MSS) tumors. MSI tumors had increased frameshift mutations, showed genetic evidence of immunoediting, had higher densities of Th1, effector-memory T cells, in situ proliferating T cells, and inhibitory PD1-PDL1 cells, had high Immunoscores, and were infiltrated with mutation-specific cytotoxic T cells. Multivariate analysis revealed that Immunoscore was superior to microsatellite instability in predicting patients' disease-specific recurrence and survival. These findings indicate that assessment of the immune status via Immunoscore provides a potent indicator of tumor recurrence beyond microsatellite-instability staging that could be an important guide for immunotherapy strategies.


Assuntos
Neoplasias Colorretais/diagnóstico , Imunoensaio/métodos , Patologia Molecular/métodos , Subpopulações de Linfócitos T/imunologia , Células Th1/imunologia , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Neoplasias Colorretais/mortalidade , Testes Imunológicos de Citotoxicidade , Análise Mutacional de DNA , Feminino , Mutação da Fase de Leitura/genética , Humanos , Memória Imunológica , Masculino , Instabilidade de Microssatélites , Repetições de Microssatélites , Valor Preditivo dos Testes , Prognóstico , Análise de Sobrevida , Transcriptoma
6.
EMBO J ; 38(2)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30498131

RESUMO

The transcription factor Blimp1 is not only an essential regulator of plasma cells, but also a risk factor for the development of autoimmune disease in humans. Here, we demonstrate in the mouse that the Prdm1 (Blimp1) gene was partially activated at the chromatin and transcription level in early B cell development, although mature Prdm1 mRNA did not accumulate due to posttranscriptional regulation. By analyzing a mouse model that facilitated ectopic Blimp1 protein expression throughout B lymphopoiesis, we could demonstrate that Blimp1 impaired B cell development by interfering with the B cell gene expression program, while leading to an increased abundance of plasma cells by promoting premature plasmablast differentiation of immature and mature B cells. With progressing age, these mice developed an autoimmune disease characterized by the presence of autoantibodies and glomerulonephritis. Hence, these data identified ectopic Blimp1 expression as a novel mechanism, through which Blimp1 can act as a risk factor in the development of autoimmune disease.


Assuntos
Linfócitos B/metabolismo , Glomerulonefrite/metabolismo , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo , Animais , Autoanticorpos/metabolismo , Linfócitos B/citologia , Diferenciação Celular , Modelos Animais de Doenças , Feminino , Redes Reguladoras de Genes , Glomerulonefrite/genética , Humanos , Masculino , Camundongos , Ativação Transcricional
7.
Vet Ophthalmol ; 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37028938

RESUMO

OBJECTIVE: To investigate the prevalence and surgical outcome of lens capsule disruption (LCD) in dogs undergoing cataract removal. ANIMALS STUDIED: Medical records of 924 eyes undergoing phacoemulsification were analyzed retrospectively. PROCEDURES: Routine cataract surgeries with or without LCD were included. Any LCD other than routine anterior capsulorhexis was defined as LCD and classified according to location and etiology. Odds ratios (OR) were calculated for maintaining vision, implantation of an artificial intraocular lens (IOL), and enucleation. RESULTS: In total, 520 eyes were included. A LCD occurred in 145 eyes (27.8%; 145/520) and affected the posterior (85.5%; 124/145), anterior (6.2%; 9/145), and equatorial lens capsule (4.8%; 7/145) and at multiple locations (3.4%; 5/145). The etiology of the LCD was spontaneous preoperative in 41 eyes (28.3%; 41/145), accidental intraoperative in 57 eyes (39.3%; 57/145), and planned in 47 eyes (32.4%; 47/145). Disruption did not increase the odds of enucleation (OR = 1.48, 95% confidence interval [CI] 0.56-3.67; p = .36). The presence of LCD significantly increased the risk of losing vision 1 year post-operatively (OR = 8.17, 95% CI 1.41-84.93; p = .007) associated with retinal detachment. However, this was not present at 2 years follow-up or in PCCC cases at any time point. An IOL was implanted in 108 eyes (108/145; 75.2%) with LCD and in 45/47 (95.7%) eyes with a PCCC. CONCLUSION: Increased surgeon awareness of possible intraoperative, accidental LCDs is important, as LCDs were relatively common and associated with increased odds for vision loss after 1 year in the present study. A prospective study investigating the causes of intraoperative, accidental LCD is warranted.

8.
BMC Med Res Methodol ; 22(1): 334, 2022 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-36567381

RESUMO

BACKGROUND: For over three decades researchers have developed critical appraisal tools (CATs) for assessing the scientific quality of research overviews. Most established CATs for reviews in evidence-based medicine and evidence-based public health (EBPH) focus on systematic reviews (SRs) with studies on experimental interventions or exposure included. EBPH- and implementation-oriented organisations and decision-makers, however, often seek access to rapid reviews (RRs) or scoping reviews (ScRs) for rapid evidence synthesis and research field exploration. Until now, no CAT is available to assess the quality of SRs, RRs, and ScRs following a unified approach. We set out to develop such a CAT. METHODS: The development process of the Critical Appraisal Tool for Health Promotion and Prevention Reviews (CAT HPPR) included six phases: (i) the definition of important review formats and complementary approaches, (ii) the identification of relevant CATs, (iii) prioritisation, selection and adaptation of quality criteria using a consensus approach, (iv) development of the rating system and bilingual guidance documents, (v) engaging with experts in the field for piloting/optimising the CAT, and (vi) approval of the final CAT. We used a pragmatic search approach to identify reporting guidelines/standards (n = 3; e.g. PRISMA, MECIR) as well as guidance documents (n = 17; e.g. for reviews with mixed-methods approach) to develop working definitions for SRs, RRs, ScRs, and other review types (esp. those defined by statistical methods or included data sources). RESULTS: We successfully identified 14 relevant CATs, predominantly for SRs (e.g. AMSTAR 2), and extracted 46 items. Following consensual discussions 15 individual criteria were included in our CAT and tailored to the review types of interest. The CAT was piloted with 14 different reviews which were eligible to be included in a new German database looking at interventions in health promotion and prevention in different implementation settings. CONCLUSIONS: The newly developed CAT HPPR follows a unique uniformed approach to assess a set of heterogeneous reviews (e.g. reviews from problem identification to policy evaluations) to assist end-users needs. Feedback of external experts showed general feasibility and satisfaction with the tool. Future studies should further formally test the validity of CAT HPPR using larger sets of reviews.


Assuntos
Promoção da Saúde , Saúde Pública , Humanos , Medicina Baseada em Evidências , Satisfação Pessoal
9.
EMBO J ; 36(6): 718-735, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28219927

RESUMO

PAX5 is a tumor suppressor in B-ALL, while the role of PAX5 fusion proteins in B-ALL development is largely unknown. Here, we studied the function of PAX5-ETV6 and PAX5-FOXP1 in mice expressing these proteins from the Pax5 locus. Both proteins arrested B-lymphopoiesis at the pro-B to pre-B-cell transition and, contrary to their proposed dominant-negative role, did not interfere with the expression of most regulated Pax5 target genes. Pax5-Etv6, but not Pax5-Foxp1, cooperated with loss of the Cdkna2a/b tumor suppressors in promoting B-ALL development. Regulated Pax5-Etv6 target genes identified in these B-ALLs encode proteins implicated in pre-B-cell receptor (BCR) signaling and migration/adhesion, which could contribute to the proliferation, survival, and tissue infiltration of leukemic B cells. Together with similar observations made in human PAX5-ETV6+ B-ALLs, these data identified PAX5-ETV6 as a potent oncoprotein that drives B-cell leukemia development.


Assuntos
Proteínas Oncogênicas/metabolismo , Fator de Transcrição PAX5/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Proteínas Proto-Oncogênicas c-ets/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/metabolismo , Animais , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Camundongos , Proteínas Oncogênicas/genética , Fator de Transcrição PAX5/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Repressoras/genética , Variante 6 da Proteína do Fator de Translocação ETS
10.
Sci Technol Adv Mater ; 20(1): 1031-1042, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31723370

RESUMO

Optically transparent, colorless Al-O-N and Al-Si-O-N coatings with discretely varied O and Si contents were fabricated by reactive direct current magnetron sputtering (R-DCMS) from elemental Al and Si targets and O2 and N2 reactive gases. The Si/Al content was adjusted through the electrical power on the Si and Al targets, while the O/N content was controlled through the O2 flow piped to the substrate in addition to the N2 flow at the targets. The structure and morphology of the coatings were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the elemental composition was obtained from Rutherford backscattering spectrometry (RBS) and heavy ion elastic recoil detection analysis (ERDA). The chemical states of the elements in the coatings were analyzed by X-ray photoelectron spectroscopy (XPS). Based on analytical results, a model describing the microstructural evolution of the Al-O-N and also previously studied Al-Si-N [1, 2, 3, 4] coatings with O and Si content, respectively, is established. The universality of the microstructural evolution of these coatings with the concentration of the added element is attributed to the extra valence electron (e-) that must be incorporated into the AlN wurtzite host lattice. In the case of Al-O-N, this additional valence charge arises from the e - acceptor O replacing N in the AlN wurtzite lattice, while the e - donor Si substituting Al fulfills that role in the Al-Si-N system. In view of future applications of ternary Al-O-N and quaternary Al-Si-O-N transparent protective coatings, their mechanical properties such as residual stress (σ), hardness (HD) and Young's modulus (E) were obtained from the curvature of films deposited onto thin substrates and by nanoindentation, respectively. Moderate compressive stress levels between -0.2 and -0.5 GPa, which suppress crack formation and film-substrate delamination, could be obtained together with HD values around 25 GPa.

11.
Pharm Res ; 35(6): 116, 2018 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-29644481

RESUMO

PURPOSE: To determine the efficacious cefazolin prophylactic dose for bariatric surgery using free subcutaneous concentrations accessed by microdialysis after 2 g or 3 g i.v. bolus dosing to morbidly obese women and POPPK modeling. METHODS: A POPPK model with variable plasma and subcutaneous tissue protein binding was developed to simultaneously describe plasma and tissue data sets. The outcomes was predicted for common surgical site infection (SSI) bacteria over 3, 4, 5 and 6 h periods postdose, as probability of target attainment (PTA) using Monte Carlo simulation. RESULTS: CFZ 2 g warrant up to 5 h SSI prophylaxis for bacteria with MICs ≤1 mg/L such as Escherichia coli and Staphylococcus aureus. For species such as Klebsiella pneumoniae, which present MIC distribution frequency of 2 mg/L, the maintenance of PTA ≥ 90% occurs with a 3 g dose for surgeries lasting up to 5 h, and 2 g dose provide an adequate response up to 4 h (PTA of 89%). CONCLUSIONS: Effectiveness of CFZ 2 g is similar to 3 g against bacteria with a MIC up to 2 mg/L, especially if the surgery does not last for more than 4 h.


Assuntos
Antibioticoprofilaxia/métodos , Cirurgia Bariátrica/efeitos adversos , Cefazolina/administração & dosagem , Modelos Biológicos , Infecção da Ferida Cirúrgica/prevenção & controle , Adulto , Cirurgia Bariátrica/métodos , Cefazolina/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Humanos , Testes de Sensibilidade Microbiana , Microdiálise , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Tela Subcutânea/metabolismo , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/microbiologia , Adulto Jovem
12.
Brief Bioinform ; 15(2): 256-78, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23341494

RESUMO

Recent advances in genome sequencing technologies provide unprecedented opportunities to characterize individual genomic landscapes and identify mutations relevant for diagnosis and therapy. Specifically, whole-exome sequencing using next-generation sequencing (NGS) technologies is gaining popularity in the human genetics community due to the moderate costs, manageable data amounts and straightforward interpretation of analysis results. While whole-exome and, in the near future, whole-genome sequencing are becoming commodities, data analysis still poses significant challenges and led to the development of a plethora of tools supporting specific parts of the analysis workflow or providing a complete solution. Here, we surveyed 205 tools for whole-genome/whole-exome sequencing data analysis supporting five distinct analytical steps: quality assessment, alignment, variant identification, variant annotation and visualization. We report an overview of the functionality, features and specific requirements of the individual tools. We then selected 32 programs for variant identification, variant annotation and visualization, which were subjected to hands-on evaluation using four data sets: one set of exome data from two patients with a rare disease for testing identification of germline mutations, two cancer data sets for testing variant callers for somatic mutations, copy number variations and structural variations, and one semi-synthetic data set for testing identification of copy number variations. Our comprehensive survey and evaluation of NGS tools provides a valuable guideline for human geneticists working on Mendelian disorders, complex diseases and cancers.


Assuntos
Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Análise de Sequência de DNA/estatística & dados numéricos , Variações do Número de Cópias de DNA , Doença/genética , Exoma , Variação Genética , Genoma Humano , Humanos , Anotação de Sequência Molecular , Mutação , Alinhamento de Sequência/estatística & dados numéricos , Software
13.
Rapid Commun Mass Spectrom ; 30(1): 221-9, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26661989

RESUMO

RATIONALE: The oxygen isotope ratio (δ(18)O) of carbohydrates derived from animals, plants, sediments, and soils provides important information about biochemical and physiological processes, past environmental conditions, and geographical origins, which are otherwise not available. Nowadays, δ(18)O analyses are often performed on carbohydrate bulk material, while compound-specific δ(18)O analyses remain challenging and methods for a wide range of individual carbohydrates are rare. METHODS: To improve the δ(18)O analysis of individual carbohydrates by gas chromatography/pyrolysis-isotope ratio mass spectrometry (GC/Pyr-IRMS) we developed a new methylation derivatization method. Carbohydrates were fully methylated within 24 h in an easy-to-handle one-pot reaction in acetonitrile, using silver oxide as proton acceptor, methyl iodide as methyl group carrier, and dimethyl sulfide as catalyst. RESULTS: The precision of the method ranged between 0.12 and 1.09‰ for the δ(18)O values of various individual carbohydrates of different classes (mono-, di-, and trisaccharides, alditols), with an accuracy of a similar order of magnitude, despite high variation in peak areas. Based on the δ(18)O values of the main isomers, important monosaccharides such as glucose and fructose could also be precisely analyzed for the first time. We tested the method on standard mixtures, honey samples, and leaf carbohydrates extracted from Pinus sylvestris, showing that the method is also applicable to different carbohydrate mixtures. CONCLUSIONS: The new methylation method shows unrivalled accuracy and precision for δ(18)O analysis of various individual carbohydrates; it is fast and easy-to-handle, and may therefore find wide-spread application.


Assuntos
Carboidratos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Isótopos de Oxigênio/análise , Mel/análise , Metilação , Extratos Vegetais/química , Reprodutibilidade dos Testes
14.
Am J Hum Genet ; 90(4): 701-7, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22424600

RESUMO

Kohlschütter-Tönz syndrome (KTS) is an autosomal-recessive disease characterized by the combination of epilepsy, psychomotor regression, and amelogenesis imperfecta. The molecular basis has not yet been elucidated. Here, we report that KTS is caused by mutations in ROGDI. Using a combination of autozygosity mapping and exome sequencing, we identified a homozygous frameshift deletion, c.229_230del (p.Leu77Alafs(∗)64), in ROGDI in two affected individuals from a consanguineous family. Molecular studies in two additional KTS-affected individuals from two unrelated Austrian and Swiss families revealed homozygosity for nonsense mutation c.286C>T (p.Gln96(∗)) and compound heterozygosity for the splice-site mutations c.531+5G>C and c.532-2A>T in ROGDI, respectively. The latter mutation was also found to be heterozygous in the mother of the Swiss affected individual in whom KTS was reported for the first time in 1974. ROGDI is highly expressed throughout the brain and other organs, but its function is largely unknown. Possible interactions with DISC1, a protein involved in diverse cytoskeletal functions, have been suggested. Our finding that ROGDI mutations cause KTS indicates that the protein product of this gene plays an important role in neuronal development as well as amelogenesis.


Assuntos
Amelogênese Imperfeita/genética , Demência/genética , Epilepsia/genética , Proteínas de Membrana/genética , Mutação , Proteínas Nucleares/genética , Sequência de Bases , Mapeamento Cromossômico , Exoma , Éxons , Feminino , Heterozigoto , Homozigoto , Humanos , Lactente , Masculino , Dados de Sequência Molecular
15.
Arch Biochem Biophys ; 588: 41-9, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26519888

RESUMO

Although a vaccine against hepatitis B virus (HBV) has been available since 1982, it is estimated that 600,000 people die every year due to HBV. An affordable oral vaccine could help alleviate the disease burden and to this end the hepatitis B surface antigen (HBsAg) was expressed in maize. Orally delivered maize material induced the strongest immune response in mice when lipid was extracted by CO2 supercritical fluid extraction (SFE), compared to full fat and hexane-extracted material. The present study provides a biochemical and biophysical basis for these immunological differences by comparing the active ingredient in the differently treated maize material. Purified maize-derived HBsAg underwent biophysical characterization by gel filtration, transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-CD, and fluorescence. Gel filtration showed that HBsAg forms higher-order oligomers and TEM demonstrated virus-like particle (VLP) formation. The VLPs obtained from SFE were more regular in shape and size compared to hexane or full fat material. In addition, SFE-derived HBsAg showed the greatest extent of α-helical structure by far UV-CD spectrum. Fluorescence experiments also revealed differences in protein conformation. This work establishes SFE-treated maize material as a viable oral vaccine candidate and advances the development of the first oral subunit vaccine.


Assuntos
Antígenos de Superfície da Hepatite B/química , Vacinas contra Hepatite B/química , Zea mays/genética , Administração Oral , Sequência de Aminoácidos , Animais , Cromatografia com Fluido Supercrítico , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/isolamento & purificação , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/genética , Humanos , Camundongos , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Plantas Geneticamente Modificadas , Conformação Proteica , Estrutura Secundária de Proteína , Espectrometria de Fluorescência , Vacinas de Plantas Comestíveis/administração & dosagem , Vacinas de Plantas Comestíveis/química , Vacinas de Plantas Comestíveis/genética , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/química , Vacinas de Partículas Semelhantes a Vírus/genética
16.
Cell Mol Life Sci ; 71(9): 1741-59, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24026398

RESUMO

Chromosomally separated, co-expressed genes can be in spatial proximity, but there is still debate about how this nuclear organization is achieved. Proposed mechanisms include global genome organization, preferential positioning of chromosome territories, or gene-gene sharing of various nuclear bodies. To investigate this question, we selected a set of genes that were co-expressed upon differentiation of human multipotent stem cells. We applied a novel multi-dimensional analysis procedure which revealed that prior to gene expression, the relative position of these genes was conserved in nuclei. Upon stem cell differentiation and concomitant gene expression, we found that co-expressed genes were closer together. In addition, we found that genes in the same 1-µm-diameter neighborhood associated with either the same splicing speckle or to a lesser extent with the same transcription factory. Dispersal of speckles by overexpression of the serine-arginine (SR) protein kinase cdc2-like kinase Clk2 led to a significant drop in the number of genes in shared neighborhoods. We demonstrate quantitatively that the frequencies of speckle and factory sharing can be explained by assuming stochastic selection of a nuclear body within a restricted sub-volume defined by the original global gene positioning present prior to gene expression. We conclude that the spatial organization of these genes is a two-step process in which transcription-induced association with nuclear bodies enhances and refines a pre-existing global organization.


Assuntos
Proteínas Nucleares/metabolismo , RNA Polimerase II/metabolismo , Ribonucleoproteínas/metabolismo , Núcleo Celular/metabolismo , Células Cultivadas , Cromossomos/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Células HEK293 , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , RNA Polimerase II/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Ribonucleoproteínas/genética , Fatores de Processamento de Serina-Arginina , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/metabolismo
17.
Int Orthop ; 37(5): 945-51, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23371427

RESUMO

PURPOSE: Mesenchymal stem cells (MSCs) express markers of hypertrophic chondrocytes during chondrogenic differentiation. We tested the suitability of parathyroid hormone-related protein (PTHrP), a regulator of chondrocyte hypertrophy in embryonic cartilage development, for the suppression of hypertrophy in an in vitro hypertrophy model of chondrifying MSCs. METHODS: Chondrogenesis was induced in human MSCs in pellet culture for two weeks and for an additional two weeks cultures were either maintained in standard chondrogenic medium or transferred to a hypertrophy-enhancing medium. PTHrP(1-40) was added to the medium throughout the culture period at concentrations from 1 to 1,000 pM. Pellets were harvested on days one, 14 and 28 for biochemical and histological analysis. RESULTS: Hypertrophic medium clearly enhanced the hypertrophic phenotype, with increased cell size, and strong alkaline phosphatase (ALP) and type X collagen staining. In chondrogenic medium, 1-100 pM PTHrP(1-40) did not inhibit chondrogenic differentiation, whereas 1,000 pM PTHrP(1-40) significantly reduced chondrogenesis. ALP activity was dose-dependently reduced by PTHrP(1-40) at 10-1,000 pM in chondrogenic conditions. Under hypertrophy-enhancing conditions, PTHrP(1-40) did not inhibit the induction of the hypertrophy. At the highest concentration (1,000 pM) in the hypertrophic group, aggregates were partially dedifferentiated and differentiated areas of these aggregates maintained their hypertrophic appearance. CONCLUSIONS: PTHrP(1-40) treatment dose-dependently reduced ALP expression in MSC pellets cultured under standard chondrogenic conditions and is thus beneficial for the maintenance of the chondrogenic phenotype in this medium condition. When cultured under hypertrophy-enhancing conditions, PTHrP(1-40) could not diminish the induced enhancement of hypertrophy in the MSC pellets.


Assuntos
Crescimento Celular/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Proteína Relacionada ao Hormônio Paratireóideo/farmacologia , Adulto , Fosfatase Alcalina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , DNA/análise , DNA/metabolismo , Relação Dose-Resposta a Droga , Humanos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia
18.
Open Vet J ; 13(8): 1037-1043, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37701662

RESUMO

Background: Reindeer are becoming popular animals within petting farms. Few case reports describe the sedation of domesticated reindeer, but none describe the use of ocular local anesthetic blocks in this species. Case Description: A 9-year-old, female, Svalbard reindeer (Rangifer tarandus platyrhynchus) presenting for removal of a squamous cell carcinoma involving the third eyelid. Standing sedation was performed using initial boluses of medetomidine and butorphanol via intramuscular injection before catheter placement and maintenance with a variable rate infusion of medetomidine. Supraorbital, auriculopalpebral, infratrochlear blocks and local infiltration of the base of the third eyelid were performed using mepivacaine. Following the surgical removal of the third eyelid, atipamazole was administered intramuscularly to antagonize the effects of medetomidine. The patient recovered without complications. Conclusion: Medetomidine-butorphanol in combination with local anesthetic blocks provided a sufficient plane of sedation and analgesia for extra ocular surgery in a domesticated reindeer.


Assuntos
Rena , Feminino , Animais , Anestésicos Locais , Butorfanol/uso terapêutico , Medetomidina , Membrana Nictitante , Anestesia Local/veterinária
19.
Int J Ment Health Nurs ; 32(1): 223-235, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36226745

RESUMO

Forms of collaborative knowledge production, such as community-academic partnerships (CAP), have been increasingly used in health care. However, instructions on how to deliver such processes are lacking. We aim to identify practice ingredients for one element within a CAP, a 6-month co-design process, during which 26 community- and 13 research-partners collaboratively designed an intervention programme for children whose parent have a mental illness. Using 22 published facilitating and hindering factors for CAP as the analytical framework, eight community-partners reflected on the activities which took place during the co-design process. From a qualitative content analysis of the data, we distilled essential practices for each CAP factor. Ten community- and eight research-partners revised the results and co-authored this article. We identified 36 practices across the 22 CAP facilitating or hindering factors. Most practices address more than one factor. Many practices relate to workshop design, facilitation methods, and relationship building. Most practices were identified for facilitating 'trust among partners', 'shared visions, goals and/or missions', 'effective/frequent communication', and 'well-structured meetings'. Fewer practices were observed for 'effective conflict resolution', 'positive community impact' and for avoiding 'excessive funding pressure/control struggles' and 'high burden of activities'. Co-designing a programme for mental healthcare is a challenging process that requires skills in process management and communication. We provide practice steps for delivering co-design activities. However, practitioners may have to adapt them to different cultural contexts. Further research is needed to analyse whether co-writing with community-partners results in a better research output and benefits for participants.


Assuntos
Transtornos Mentais , Saúde Mental , Humanos , Criança , Áustria , Pais , Atenção à Saúde , Transtornos Mentais/terapia
20.
Hepatology ; 53(3): 895-904, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21374661

RESUMO

UNLABELLED: Diethylnitrosamine (DEN) is a hepatic procarcinogen which is frequently used as an inducer of hepatocellular carcinoma (HCC) in mice. Although mice after DEN exposure are among the most widely used models for liver tumorigenesis, a detailed, mechanistic characterization of the longitudinal changes in the respective tumor genomes has never been performed. Here we established the chronological order of genetic alterations during DEN carcinogenesis by examining mice at different points in time. Tumor samples were isolated by laser microdissection and subjected to array-comparative genomic hybridization (array-CGH) and sequencing analysis. Chromosomal gains and losses were observed in tumors by week 32 and increased significantly by week 56. Loss of distal chromosome 4q, including the tumor suppressors Runx3 and Nr0b2/Shp, was a frequent early event and persisted during all tumor stages. Surprisingly, sequencing revealed that ß-catenin mutations occurred late and were clearly preceded by chromosomal instability. Thus, contrary to common belief, ß-catenin mutations and activation of the Wnt/ß-catenin pathway are not involved in tumor initiation in this model of chemical hepatocarcinogenesis. CONCLUSION: Our study suggests that the majority of the current knowledge about genomic changes in HCC is based on advanced tumor lesions and that systematic analyses of the chronologic order including early lesions may reveal new, unexpected findings.


Assuntos
Instabilidade Genômica , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/genética , Hibridização Genômica Comparativa , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Variações do Número de Cópias de DNA , Dietilnitrosamina , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/genética , Masculino , Camundongos , Receptores Citoplasmáticos e Nucleares/genética , beta Catenina/genética
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