RESUMO
Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.
Assuntos
Anormalidades Múltiplas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Antígenos de Neoplasias/genética , Cerebelo/anormalidades , Anormalidades do Olho/genética , Doenças Renais Císticas/genética , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas de Neoplasias/genética , Retina/anormalidades , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/epidemiologia , Anormalidades Múltiplas/fisiopatologia , Alelos , Proteínas de Ciclo Celular , Cerebelo/diagnóstico por imagem , Cerebelo/fisiopatologia , Proteínas do Citoesqueleto , Anormalidades do Olho/diagnóstico por imagem , Anormalidades do Olho/epidemiologia , Anormalidades do Olho/fisiopatologia , Feminino , Heterogeneidade Genética , Predisposição Genética para Doença , Humanos , Japão/epidemiologia , Doenças Renais Císticas/diagnóstico por imagem , Doenças Renais Císticas/epidemiologia , Doenças Renais Císticas/fisiopatologia , Masculino , Mutação , Omã/epidemiologia , Linhagem , Retina/diagnóstico por imagem , Retina/fisiopatologiaRESUMO
INTRODUCTION: This study evaluated the effects of the CYP2D6*10 genotype on steady-state plasma concentrations of enantiomeric mirtazapine (MIR) and N-desmethylmirtazapine (DMIR) in Japanese patients. METHODS: Subjects were 77 Japanese patients treated with racemic MIR. Steady-state plasma concentrations of MIR and DMIR enantiomers were measured using stereoselective liquid chromatography. Polymerase chain reaction was used to determine the CYP2D6 genotypes. RESULTS: After correcting for dose and body weight, smokers (n=15) had significantly lower S-(+)-MIR than nonsmokers (n=55) (15.1±17.8 vs. 23.9±17.8 ng/mL/mg/kg, Kruskal-Wallis test, p=0.034). One-way analysis of variance revealed that CYP2D6*10 homozygotes had significantly higher corrected plasma concentrations of S-(+)-MIR than the no-variant allele group (p=0.034). Multiple regression analysis revealed a significant positive correlation between the number of CYP2D6*10 alleles and corrected plasma concentrations of S-(+)-MIR. These results yielded the following final model: corrected plasma concentration of S-(+)-MIR=15.9+7.30×(number of CYP2D6*10 alleles) (R=0.279, p=0.023, coefficient of determination (R(2))=0.078). CONCLUSION: Homozygous CYP2D6*10 alleles and smoking have a significant impact on the metabolism of S-(+)-MIR in Japanese patients.
Assuntos
Antidepressivos Tricíclicos/sangue , Citocromo P-450 CYP2D6/genética , Transtorno Depressivo/tratamento farmacológico , Genótipo , Mianserina/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Antidepressivos Tricíclicos/uso terapêutico , Transtorno Depressivo/sangue , Transtorno Depressivo/genética , Feminino , Humanos , Japão , Masculino , Mianserina/sangue , Mianserina/uso terapêutico , Pessoa de Meia-Idade , Mirtazapina , Farmacogenética , Adulto JovemRESUMO
An increased incidence of sudden death has been observed among patients treated with antidepressants. A prolonged QTc interval is a known prognostic factor for fatal arrhythmia, and several studies have shown that the use of antidepressants can cause a prolonged QTc interval. However, few studies, especially in Japan, have compared the effects of multiple drugs on QTc interval or examined dose relationships in a clinical setting.We compared the effects of antidepressants on QT interval, corrected to QTc by Bazett's formula, in 729 Japanese patients who were diagnosed with mood disorder.Using stepwise multiple linear regression analysis, we found that the use of tricyclic antidepressants (P<0.01) and concomitant use of antipsychotics (P<0.05), as well as advanced age and being female (known factors for prolonged QTc interval; both P<0.01), significantly prolonged the QTc interval. Analysis of individual antidepressants also revealed that the use of clomipramine (P<0.01) and amitriptyline (P<0.05) significantly prolonged the QTc interval.Our results reveal that tricyclic antidepressants, especially clomipramine and amitriptyline, confer a risk of prolonged QTc interval in a dose-dependent manner. The selective serotonin reuptake inhibitors investigated (fluvoxamine, paroxetine, sertraline) were not indicated as risk factors for QTc prolongation.
Assuntos
Antidepressivos Tricíclicos/efeitos adversos , Antipsicóticos/efeitos adversos , Povo Asiático/psicologia , Síndrome do QT Longo/induzido quimicamente , Transtornos do Humor/fisiopatologia , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Fatores Etários , Antidepressivos Tricíclicos/administração & dosagem , Antipsicóticos/administração & dosagem , Relação Dose-Resposta a Droga , Quimioterapia Combinada/efeitos adversos , Eletrocardiografia/psicologia , Eletrocardiografia/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/tratamento farmacológico , Análise de Regressão , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Caracteres SexuaisRESUMO
In the larval bester, a hybrid sturgeon of beluga Huso huso and sterlet Acipenser ruthenus, development of cartilage around the notochord began 7 days post hatch (dph) (14.0 mm, total length, L(T)). The vertebral cartilage develops in the following sequence: basidorsals and basiventrals, neural canals, neural spines and ribs. The development of ribs remained incomplete in the largest specimen (181 dph, 179 mm L(T) ) that was examined. Endoskeletal development of the fins began 4 dph for the dorsal and anal fins, 6 dph for the pectoral fin and 10 dph for the caudal and pelvic fins. Complete elements of all fins were observed by 91 dph and complete ossification of fin rays was observed by 122 dph in the double-stained specimens. Observation of the histological sections, however, suggested that ossification occurred soon after the formation of the organic matrix in the fin rays. Dorsal scutes were first visible by 25 dph, followed by the lateral and ventral scutes, which were visible by 37 and 44 dph, respectively. The number of scutes was fixed at 44, 59 and 91 dph and ossification was complete by 59 (dorsal) and 91 dph (lateral and ventral scutes) in the double-stained specimens. Ossification occurred soon after the formation of the scute organic matrix in the histological sections. Four types of scales were observed in the H. huso×A. ruthenus hybrid. Median predorsal, preanal and small scales on the anterior section of the head were visible by 59 dph. Scales on the caudal fin were visible by 91 dph and a variable assemblage of scales anterior to the anal fin was visible by 122 dph. Both the scutes and scales developed in a process that is similar to that of intramembranous ossification.
Assuntos
Nadadeiras de Animais/crescimento & desenvolvimento , Peixes/crescimento & desenvolvimento , Coluna Vertebral/crescimento & desenvolvimento , Animais , Cartilagem/crescimento & desenvolvimento , Larva/crescimento & desenvolvimentoRESUMO
BACKGROUND: The F-box protein S-phase kinase-associated protein 2 (Skp2) positively regulates the G1-S transition by promoting degradation of the cyclin-dependent kinase inhibitor p27(kip1) (p27). Recent evidence has indicated an oncogenic role of Skp2 in not only carcinogenesis but also lymphomagenesis. MATERIALS AND METHODS: Clinicopathologic features and immunohistochemical expression of Skp2 and p27 were studied retrospectively in 671 patients treated with cyclophosphamide, vincristine, doxorubicin and prednisolone (CHOP) or cyclophosphamide, vincristine, doxorubicin and prednisolone plus rituximab (R-CHOP). The median follow-up periods were 43.2 months in the CHOP group (n = 425) and 24.0 months in the R-CHOP group (n = 246). RESULTS: High Skp2 or low p27 expression correlated significantly with poor overall survival (OS) and progression-free survival (P < 0.001) in both treatment groups. The prognostic value of Skp2 or p27 expression was independent of the parameters included in the International Prognostic Index by multivariate analysis. Patients with high Skp2 expression in combination with low p27 expression showed the worst survival. CONCLUSIONS: Addition of rituximab to the CHOP regimen did not provide a beneficial outcome to patients with diffuse large B-cell lymphoma with high Skp2 expression and low p27 expression. Skp2 and p27 may be useful prognostic markers in the rituximab era.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Proteínas Quinases Associadas a Fase S/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Murinos , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Biomarcadores Tumorais/metabolismo , Ciclofosfamida , Doxorrubicina , Feminino , Humanos , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Prednisona , Prognóstico , Estudos Retrospectivos , Rituximab , Análise de Sobrevida , Vincristina , Adulto JovemRESUMO
Janus kinase 2 (JAK2) V617F mutation has been regarded as the major cause of myeloproliferative disorders (MPD). However, the mechanisms of abnormal cell growth by JAK2V617F have not been elucidated. In this study, cell cycle regulatory protein expression was analyzed using JAK2V617F-Ba/F3 and mock-Ba/F3. JAK2V617F-Ba/F3, but not mock-Ba/F3, showed IL-3 independent cell growth and constitutive STATs activation. Deregulation of p27(Kip1), the cell cycle regulator at the G1 to S transition, was observed in JAK2V617F-Ba/F3 but not in mock-control. p27(Kip1) deregulation was not due to p27(Kip1) mRNA level but due to high Skp2 expression, a subunit of ubiquitin E3 ligase, through the STAT binding in the Skp2 promoter. Like JAK2V617F overexpression, constitutively active STAT5 or STAT3 induced aberrant p27(Kip1) expression of Ba/F3 cells. Similar findings were observed in BCR/ABL-transfected Ba/F3. Our results elucidate the regulatory mechanism by which JAK2V617F modulates Skp2 gene expression through the STAT transcription factors.
Assuntos
Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Regulação da Expressão Gênica , Janus Quinase 2/metabolismo , Proteínas Quinases Associadas a Fase S/genética , Fatores de Transcrição STAT/metabolismo , Animais , Linhagem Celular Tumoral , Ensaio de Desvio de Mobilidade Eletroforética , Interleucina-3/metabolismo , Janus Quinase 2/genética , Camundongos , Mutação , Regiões Promotoras GenéticasRESUMO
BACKGROUND: Psychiatric comorbidity of autism spectrum disorder (ASD) has not been well examined. METHODS: Mood disorders in 44 consecutive outpatients with high-functioning ASD were examined at a university hospital according to DSM-IV. Inclusion criteria were an IQ of 70 or higher on the Wechsler Intelligence Scale and age of 12 years or over. RESULTS: Sixteen patients (36.4%) were diagnosed with mood disorder. Of these 16 patients, four were diagnosed as having major depressive disorder, two patients as bipolar I disorder, six patients as bipolar II disorder, and four patients as bipolar disorder not otherwise specified. Bipolar disorder accounted for 75% of cases. Twelve patients had Asperger disorder and four patients had pervasive developmental disorder not otherwise specified. None of the patients had autistic disorder. LIMITATIONS: The sample size was small. We could not use Autism Diagnostic Interview - Revised. Referral bias could not be avoided in this study. CONCLUSIONS: The major comorbid mood disorder in patients with high-functioning ASD is bipolar disorder and not major depressive disorder. The autistic spectrum may share common vulnerability genes with the bipolar spectrum.
Assuntos
Assistência Ambulatorial , Síndrome de Asperger/epidemiologia , Transtorno Autístico/epidemiologia , Transtorno Bipolar/epidemiologia , Transtornos Globais do Desenvolvimento Infantil/epidemiologia , Adolescente , Adulto , Síndrome de Asperger/diagnóstico , Transtorno Autístico/diagnóstico , Transtorno Bipolar/diagnóstico , Criança , Transtornos Globais do Desenvolvimento Infantil/diagnóstico , Comorbidade , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Seguimentos , Humanos , Masculino , Prevalência , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários , Escalas de Wechsler , Adulto JovemRESUMO
beta-Thujaplicin (hinokitiol) is a tropolone derivative present in the heartwood of cupressaceous plants and is used as a medicine, a food additive, and a preservative, and in cosmetics as hair tonic. The cultured plant cells of Nicotiana tabacum glycosylated beta-thujaplicin to two glucosides, 4-isopropyltropolone 2-O-beta-D-glucoside (6%) and 6-isopropyltropolone 2-O-beta-D-glucoside (12%), and two gentiobiosides, 4-isopropyltropolone 2-O-beta-D-gentiobioside (2%) and 6-isopropyltropolone 2-O-beta-D-gentiobioside (5%) after 48 h incubation. The use of immobilized cells of N. tabacum in sodium alginate gel much improved the yield of the products; the glycosylation of beta-thujaplicin with immobilized N. tabacum gave the glycoside products, 4-isopropyltropolone 2-O-beta-D-glucoside (11%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (6%), 6-isopropyltropolone 2-O-beta-D-glucoside (20%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (10%). On the other hand, 4-isopropyltropolone 2-O-beta-D-glucoside (14%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (7%), 6-isopropyltropolone 2-O-beta-D-glucoside (33%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (13%) were obtained through the biotransformation with immobilized cells in the medium without iron ions. In comparison with the case of bioconversion in the normal medium containing iron ions, removal of iron ions improved the yields of products.
Assuntos
Glicosídeos/metabolismo , Monoterpenos/metabolismo , Nicotiana/metabolismo , Tropolona/análogos & derivados , Linhagem Celular , Estrutura Molecular , Monoterpenos/química , Tropolona/química , Tropolona/metabolismoRESUMO
Signal transducer and activator of transcription 3 (STAT3) play key roles in the intracellular signaling pathways of the interleukin (IL)-6 family of cytokines, which exhibit a diverse set of cellular responses, including cell proliferation and differentiation. Dysregulated IL-6/STAT3 signaling is involved in the pathogenesis of several diseases, for example autoimmune diseases and tumors. Type I interferon (IFN) induces the expression of proapoptotic genes and has been used in the clinical treatment of several tumors. In the present study, we found that type I IFN suppressed IL-6/STAT3-mediated transcription and gene expression. Furthermore, a type I IFN-induced protein, Daxx, also suppressed STAT3-mediated transcriptional activation, while overexpression of Daxx inhibited IL-6/STAT3-mediated gene expression. Importantly, small-interfering RNA-mediated reduction of Daxx expression enhanced IL-6/leukemia inhibitory factor (LIF)-induced STAT3-dependent transcription. Co-immunoprecipitation studies revealed a physical interaction between Daxx and STAT3 in transiently transfected 293T cells. We further found that Daxx and STAT3 were co-localized in the nucleus. These results indicate that Daxx may serve as a transcriptional regulator of type I IFN-mediated suppression of the IL-6/STAT3 signaling pathway.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Nucleares/metabolismo , Fator de Transcrição STAT3/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Linhagem Celular , Núcleo Celular/metabolismo , Proteínas Correpressoras , Regulação da Expressão Gênica/fisiologia , Humanos , Imunoprecipitação , Chaperonas Moleculares , Proteínas Nucleares/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/fisiologiaRESUMO
To test the hypothesis that burn and smoke injury will deplete tissue alpha-tocopherol and cause its faster plasma disappearance, deuterium-labeled vitamin E was administered to sheep exposed to both surface skin burn and smoke insufflation, which cause injuries similar to those of human victims of fire accidents. Two different protocols were used: (1) deuterated vitamin E was administered orally with food at time 0 (just before injury) or (2) the labeled vitamin E was administered orally with food the day before injury. The animals, which had been operatively prepared seven days before, were anesthetized and then received both 40% body surface area third-degree burn and 48 breaths of cotton smoke or sham injuries. All were resuscitated with Ringer's lactate solution (4 ml/kg/% BSA burn/24 h) and mechanically ventilated. Blood samples were collected at various times after vitamin E dosing. In both studies the depletion of plasma alpha-tocopherol was faster in the injured sheep. The sheep given deuterated vitamin E 24 h before injury had similar maximum alpha-tocopherol concentrations at similar times. The exponential rates of alpha-tocopherol disappearance were 1.5 times greater and half-lives were 12 h shorter (p < 0.05) in the injured sheep. In separate studies, various tissues were obtained from sheep that were sacrificed from 4 to 48 h after injury. The liver alpha-tocopherol concentrations in sheep killed at various times after injury seem to show a linear decrease at a rate of 0.1 nmol alpha-tocopherol/g liver per hour, suggesting that the liver is supplying alpha-tocopherol to maintain the plasma and lung alpha-tocopherol concentrations, but that this injury is so severe the liver is unable to maintain lung alpha-tocopherol concentrations. These findings suggest that alpha-tocopherol should be administered to burn patients to prevent vitamin E depletion and to protect against oxidative stress from burn injury.
Assuntos
Queimaduras/complicações , Fumaça/efeitos adversos , Fumar/efeitos adversos , Deficiência de Vitamina E/etiologia , Vitamina E/metabolismo , Animais , Deutério , Modelos Animais de Doenças , Cinética , Ovinos , Fatores de Tempo , VigíliaRESUMO
Since granulocyte colony-stimulating factor (G-CSF) is thought to be a granulocyte lineage-specific cytokine, G-CSF receptors on blood cells other than those of granulocyte or monocyte lineage have not been well investigated. We now report that G-CSF receptors are present on platelets. The expression of G-CSF receptors on platelets was demonstrated by flow cytometry and radioreceptor assay. The mean number of G-CSF-binding sites per cell was 41 and the binding affinity was high (Kd 300 pM), similar to the affinity observed on granulocytes. Cross-linking assay revealed that G-CSF receptors were present on a single subunit protein of approximately 150 kD on the platelets. To clarify whether or not G-CSF might produce some direct functional influence on platelet response, the effects on platelet aggregation were studied. Although G-CSF itself did not affect platelet aggregation in vitro, preincubation with G-CSF augmented a secondary aggregation of platelets induced by low concentrations of adenosine diphosphate (ADP). There was a dose-response relationship for this G-CSF activity at concentrations of up to 10 ng/ml. Furthermore, the augmented ADP-induced secondary aggregation of platelets on G-CSF receptors was completely abrogated in the presence of anti-G-CSF polyclonal antibodies. These results indicate that platelets possess functional G-CSF receptors.
Assuntos
Plaquetas/ultraestrutura , Receptores de Fator Estimulador de Colônias de Granulócitos/fisiologia , Difosfato de Adenosina/farmacologia , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Agregação Plaquetária/efeitos dos fármacos , Ensaio RadioliganteRESUMO
By searching a database of expressed sequences, we identified a member of the signal transducers and activators of transcription (Stat) family of proteins. Human and murine full-length cDNA clones were obtained and sequenced. The sequence of the human cDNA was identical to the recently published sequence for interleukin-4 (IL-4)-Stat (J. Hou, U. Schindler, W.J. Henzel, T.C. Ho, M. Brasseur, and S. L. McKnight, Science 265:1701-1706, 1994), while the murine Stat6 amino acid and nucleotide sequences were 83 and 84% identical to the human sequences, respectively. Using Stat6-specific antiserum, we demonstrated that Stat6 is rapidly tyrosine phosphorylated following stimulation of appropriate cell lines with IL-4 or IL-3 but is not detectably phosphorylated following stimulation with IL-2, IL-12, or erythropoietin. In contrast, IL-2, IL-3, and erythropoietin induce the tyrosine phosphorylation of Stat5 while IL-12 uniquely induces the tyrosine phosphorylation of Stat4. Inducible tyrosine phosphorylation of Stat6 requires the membrane-distal region of the IL-4 receptor alpha chain. This region of the receptor is not required for cell growth, demonstrating that Stat6 tyrosine phosphorylation does not contribute to mitogenesis.
Assuntos
Interleucina-3/farmacologia , Interleucina-4/farmacologia , Transativadores/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Humanos , Camundongos , Mitose/efeitos dos fármacos , Dados de Sequência Molecular , Fosforilação , Fator de Transcrição STAT6 , Análise de Sequência , Transativadores/metabolismo , Fatores de Transcrição/isolamento & purificação , Fatores de Transcrição/metabolismoRESUMO
Cultured plant cells of Marchantia polymorpha were examined for their ability to reduce beta-keto ester, 2-methyl-3-oxobutanoate. The cells reduced ethyl 2-methyl-3-oxobutanoate to predominantly yield the anti-product, ethyl (2S,3S)-3-hydroxy-2-methylbutanoate, with 92% diastereomeric excess and over 99% enantiomeric excess. The use of immobilized cells of M. polymorpha in calcium alginate gel improved the diastereomeric excess of the product (97% de). In addition, the large-scale reduction of 75 g of ethyl 2-methyl-3-oxobutanoate with immobilized M. polymorpha gave the product with 97% de and >99% ee in 92% yield.
Assuntos
Hidroxibutiratos/metabolismo , Marchantia/metabolismo , Células Imobilizadas , Isomerismo , Marchantia/citologia , OxirreduçãoRESUMO
Somatic inactivating mutations in epigenetic regulators are frequently found in combination in myelodysplastic syndrome (MDS). However, the mechanisms by which combinatory mutations in epigenetic regulators promote the development of MDS remain unknown. Here we performed epigenomic profiling of hematopoietic progenitors in MDS mice hypomorphic for Tet2 following the loss of the polycomb-group gene Ezh2 (Tet2KD/KDEzh2Δ/Δ). Aberrant DNA methylation propagated in a sequential manner from a Tet2-insufficient state to advanced MDS with deletion of Ezh2. Hyper-differentially methylated regions (hyper-DMRs) in Tet2KD/KDEzh2Δ/Δ MDS hematopoietic stem/progenitor cells were largely distinct from those in each single mutant and correlated with transcriptional repression. Although Tet2 hypomorph was responsible for enhancer hypermethylation, the loss of Ezh2 induced hyper-DMRs that were enriched for CpG islands of polycomb targets. Notably, Ezh2 targets largely lost the H3K27me3 mark while acquiring a significantly higher level of DNA methylation than Ezh1 targets that retained the mark. These findings indicate that Ezh2 targets are the major targets of the epigenetic switch in MDS with Ezh2 insufficiency. Our results provide a detailed trail for the epigenetic drift in a well-defined MDS model and demonstrate that the combined dysfunction of epigenetic regulators cooperatively remodels the epigenome in the pathogenesis of MDS.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Regulação da Expressão Gênica , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Ilhas de CpG , Metilação de DNA , Proteínas de Ligação a DNA/genética , Dioxigenases , Modelos Animais de Doenças , Elementos Facilitadores Genéticos , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Hematopoese/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Motivos de Nucleotídeos , Ligação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Mutations of calreticulin (CALR) are detected in 25-30% of patients with essential thrombocythemia (ET) or primary myelofibrosis and cause frameshifts that result in proteins with a novel C-terminal. We demonstrate that CALR mutations activated signal transducer and activator of transcription 5 (STAT5) in 293T cells in the presence of thrombopoietin receptor (MPL). Human megakaryocytic CMK11-5 cells and erythroleukemic F-36P-MPL cells with knocked-in CALR mutations showed increased growth and acquisition of cytokine-independent growth, respectively, accompanied by STAT5 phosphorylation. Transgenic mice expressing a human CALR mutation with a 52 bp deletion (CALRdel52-transgenic mice (TG)) developed ET, with an increase in platelet count, but not hemoglobin level or white blood cell count, in association with an increase in bone marrow (BM) mature megakaryocytes. CALRdel52 BM cells did not drive away wild-type (WT) BM cells in in vivo competitive serial transplantation assays, suggesting that the self-renewal capacity of CALRdel52 hematopoietic stem cells (HSCs) was comparable to that of WT HSCs. Therapy with the Janus kinase (JAK) inhibitor ruxolitinib ameliorated the thrombocytosis in TG mice and attenuated the increase in number of BM megakaryocytes and HSCs. Taken together, our study provides a model showing that the C-terminal of mutant CALR activated JAK-STAT signaling specifically downstream of MPL and may have a central role in CALR-induced myeloproliferative neoplasms.
Assuntos
Calreticulina/genética , Animais , Autorrenovação Celular , Células HEK293 , Células-Tronco Hematopoéticas , Humanos , Janus Quinases/antagonistas & inibidores , Camundongos , Camundongos Transgênicos , Transtornos Mieloproliferativos/induzido quimicamente , Transtornos Mieloproliferativos/etiologia , Nitrilas , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Pirimidinas , Receptores de Trombopoetina , Fator de Transcrição STAT5/metabolismo , Trombocitemia Essencial/tratamento farmacológico , Trombocitemia Essencial/genéticaRESUMO
Adult T-cell leukemia (ATL) develops via multiple oncogenic steps in human T-cell leukemia virus type I (HTLV-I) carriers. To better understand pathogenesis of ATL, we developed a novel xenogeneic engraftment model in which primary ATL cells are intravenously transplanted into neonatal nonobese diabetic (NOD)/severe-combined immunodeficiency (SCID)/beta2-microglobulin(null) (NOD/SCID/beta2m(null)) mice. Acute-type ATL cells engrafted in the peripheral blood and in the lymph nodes of recipients at a high efficiency. Engrafted ATL cells were dually positive for human CD4 and CD25, and displayed patterns of HTLV-I integration identical to those of donors by Southern blot analysis. These cells infiltrated into recipients' liver, and formed nodular lesions, recapitulating the clinical feature of each patient. In contrast, in smoldering-type ATL cases, multiple clones of ATL cells engrafted efficiently in NOD/SCID/beta2m(null) mice. When smoldering-type ATL cells were retransplanted into secondary NOD/SCID/beta2m(null) recipients, single HTLV-I-infected clones became predominant, suggesting that clones with dominant proliferative activity can be competitively selected in this xenogeneic system. Taken together, the NOD/SCID/beta2m(null) newborn system is useful to understand kinetics, metastasis, and disease progression of ATL in vivo.
Assuntos
Modelos Animais de Doenças , Leucemia-Linfoma de Células T do Adulto/patologia , Transplante de Neoplasias , Anemia Refratária com Excesso de Blastos/patologia , Animais , Sangue , Proliferação de Células , Células Clonais/patologia , Sobrevivência de Enxerto , Humanos , Leucemia-Linfoma de Células T do Adulto/etiologia , Infiltração Leucêmica , Fígado , Linfonodos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Transplante Heterólogo , Microglobulina beta-2/genéticaRESUMO
The biological roles of the soluble granulocyte colony-stimulating factor (G-CSF) receptor, which arises as a result of alternative RNA splicing, are as yet unknown. In this study, we examined the in vitro effect of a chimeric protein composed of the extracellular region of a murine G-CSF receptor and the human IgG1 Fc region because a human natural soluble G-CSF receptor was not available. First, we found that this chimeric soluble G-CSF receptor could inhibit the biological activity of G-CSF on normal bone marrow colony formation. Because G-CSF also plays an important role in the proliferation of leukemic blast cells, we next examined the effect of the soluble G-CSF receptor on leukemic blast colony formation in 10 acute myeloblastic leukemia cases. Although G-CSF stimulated the proliferation of leukemic progenitor cells to form leukemic blast colonies, the chimeric soluble G-CSF receptor completely inhibited this stimulatory effect. Furthermore, the chimeric soluble G-CSF receptor also inhibited spontaneous leukemic blast colony formation in two cases. Because a high concentration of G-CSF was observed in the supernatants of leukemic blast cells from these two cases, it seems likely that the soluble G-CSF receptor cut off the autocrine growth mechanism of leukemic blast cells mediated by G-CSF. These findings suggest the possibility that the soluble G-CSF receptor could be used in a clinical application for acute myeloblastic leukemia patients in the future.
Assuntos
Crise Blástica/patologia , Fragmentos Fc das Imunoglobulinas , Leucemia Mieloide Aguda/patologia , Receptores de Fator Estimulador de Colônias de Granulócitos , Proteínas Recombinantes de Fusão/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Camundongos , Proteínas Recombinantes de Fusão/químicaRESUMO
Granulocyte colony-stimulating factor (G-CSF) receptors on the gated leukemic blast cells from newly diagnosed patients with acute leukemia or crisis of chronic myelogenous leukemia were investigated using flow cytometric detection. Surface marker analysis and cytochemical studies were conducted simultaneously to characterize the blast cells. Among 24 leukemia cases examined, G-CSF receptor-positive blast cells were detected in all 11 cases of acute myeloblastic leukemia even though the percentage range of positive cells was widely variable. On the other hand, they were not detected on the blast cells from patients with peroxidase-negative acute lymphoblastic leukemia with no myeloid surface antigens. However, G-CSF receptors were demonstrated in significant amounts on blast cells from 5 of 8 cases of peroxidase-negative acute leukemia expressing both myeloid and lymphoid surface antigens (biphenotypic leukemia). The percentage of blast cells positive for G-CSF receptors was significantly smaller in biphenotypic cases [33 +/- 14% (SD)] than in acute myeloblastic leukemia cases [65 +/- 22%] (P less than 0.01). The percentage expression of CD13 antigen by blast cells was significantly related to their percentage positivity for G-CSF receptors (rs = 0.50, P less than 0.05). These findings indicate that the distribution of flow cytometrically detectable G-CSF receptors on leukemic cells possessing myeloid characteristics may be related to the maturation process.
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia/metabolismo , Receptores de Fator Estimulador de Colônias de Granulócitos/análise , Antígenos CD/análise , Antígenos de Diferenciação/análise , Antígenos de Neoplasias/análise , Crise Blástica/metabolismo , Medula Óssea/imunologia , Medula Óssea/metabolismo , Citometria de Fluxo , Humanos , Imunofenotipagem , Leucemia/imunologia , Leucemia/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Linfonodos/imunologia , Linfonodos/metabolismo , Neprilisina , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologiaRESUMO
BACKGROUND: This study evaluated the indications and outcome for transanal endoscopic surgery (TES) used to manage rectal carcinoid tumor as compared with those of conventional transanal local resection (TAR). METHODS: The retrospective study subjects were 28 patients with rectal carcinoid tumor treated by TES (n = 17) or TAR (n = 11) between January 1995 and December 2001. Patient and tumor characteristics, operative results, and postoperative outcomes were compared between the two groups. RESULTS: The distance from the anal verge to the distal tumor margin in the TES group (range, 4-12 cm; median, 6.8 cm) was significantly greater than in the TAR group (range, 3-6 cm; median, 4.5 cm) (p = 0.001). The median tumor diameter was 5.5 mm (range, 3-11 mm) in the TES group and 5.0 mm (range, 3-8 mm) in the TAR group, showing no statistical difference. Microscopically, resected specimens in both groups were typical carcinoid tumors restricted to the submucosal layer. No recurrence was noted in either group. CONCLUSION: Whereas TES is useful for patients with small rectal carcinoid tumor of typical histology within the submucosal layer in the upper and middle rectum, TAR is effective for accessing the lower rectum.
Assuntos
Tumor Carcinoide/cirurgia , Proctoscopia/métodos , Neoplasias Retais/cirurgia , Adulto , Idoso , Canal Anal , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
We present the first report of a T-helper cell line, HUT 102, constitutively producing both granulocyte-macrophage colony-stimulating factor (GM-CSF) and monocytic colony-stimulating factor (M-CSF), as detected by sensitive enzyme-linked immunosorbent assays and Northern blot analysis. However, neither amplification nor structural change of the GM-CSF and M-CSF genes was detected by Southern blot analysis. In the case of HUT 102, in which human T-lymphotropic leukemia virus type I (HTLV-I) is integrated, the viral protein, which acts as a trans-acting transcriptional activator, may induce the production of both GM-CSF and M-CSF.