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1.
Eur J Pharmacol ; 924: 174941, 2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35398031

RESUMO

Pathological osteolysis is associated with excessive bone resorption by activated osteoclasts. Given that receptor activator of NF-kB and its ligand (RANKL) are key players in the differentiation and activation of osteoclasts, the RANKL/RANK signaling pathway is considered a promising target for the development of effective osteoclastogenesis inhibitors. We previously found that the orally available compound, AS2690168, suppresses RANKL-induced osteoclastogenesis of RAW264 cells. In this report, we further characterized the pharmacological profiles of AS2690168 in vitro and in vivo. AS2690168 suppressed soluble RANKL (sRANKL)-induced NFATc1 mRNA expression in RAW264 cells at 0.3 and 3.0 µM. It also suppressed calcium release from parathyroid hormone-stimulated mouse calvaria with an IC50 value of 0.46 µM. Oral administration of AS2690168 completely suppressed the decrease in femoral bone mineral content in an sRANKL-induced osteopenic mice model at 3.0 mg/kg. It also significantly suppressed the decrease in femoral bone mineral density and increase in serum tartrate-resistant acid phosphatase-5b levels in ovariectomized rats at doses of 0.3, 1 and 3 mg/kg. Finally, AS260168 suppressed the increase in urine deoxypyridinoline in a rat prednisolone-induced osteoporosis model at 10 mg/kg. These results suggest that AS2690168 is a promising treatment for bone disorders with excessive bone resorption.


Assuntos
Reabsorção Óssea , Ligante RANK , Animais , Reabsorção Óssea/patologia , Diferenciação Celular , Ligantes , Camundongos , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/metabolismo , Osteoclastos , Osteogênese , Ligante RANK/farmacologia , Ratos , Receptor Ativador de Fator Nuclear kappa-B , Transdução de Sinais
2.
Genes Genet Syst ; 96(6): 259-269, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35264511

RESUMO

A spontaneous mutation, enNK14, was a new allele of engrailed (en) in Drosophila melanogaster. Females of enNK14 have three spermathecae, instead of two in wild type, under a wide range of developmental temperatures, while the males show no abnormal phenotype. Spermathecae of the mutant female can accept inseminated sperms, albeit with a delay of at least an hour until full acceptance compared with wild type. The time course of decrease in the number of stored sperms was thoroughly similar between the mutant and wild type. enNK14 females produced fewer progeny than wild type females despite storing a larger number of sperms. The delay of sperm entry and lower fecundity suggested some functional defects in secretory products of the spermathecae. In addition, some spermathecae in the mutant were accompanied by a mass of brown pigments in the adipose tissue surrounding the capsule. Six contiguous amino acids, Ser340-Ala345, were replaced by one Thr in enNK14. In another mutant, enspt, Ser325 was also shown to be substituted by a Cys. These amino acid changes were located within a serine-rich region, in which Ser325, Ser340 and Thr341 were suggested as targets of Protein Kinase C by an in silico analysis. The splicing pattern of en mRNA did not differ between enNK14 and wild type in embryo, larva, pupa or adult. Our results suggest that en plays an important role in determining the number of spermathecae as well as in sperm storage function in the Drosophila female.


Assuntos
Drosophila melanogaster , Espermatozoides , Alelos , Animais , Drosophila melanogaster/genética , Feminino , Fertilidade/genética , Masculino , Fenótipo
3.
Curr Biol ; 32(2): 386-397.e6, 2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-34875230

RESUMO

The role of processing bodies (P-bodies), key sites of post-transcriptional control, in adult stem cells remains poorly understood. Here, we report that adult Drosophila intestinal stem cells, but not surrounding differentiated cells such as absorptive enterocytes (ECs), harbor P-bodies that contain Drosophila orthologs of mammalian P-body components DDX6, EDC3, EDC4, and LSM14A/B. A targeted RNAi screen in intestinal progenitor cells identified 39 previously known and 64 novel P-body regulators, including Patr-1, a gene necessary for P-body assembly. Loss of Patr-1-dependent P-bodies leads to a loss of stem cells that is associated with inappropriate expression of EC-fate gene nubbin. Transcriptomic analysis of progenitor cells identifies a cadre of such weakly transcribed pro-differentiation transcripts that are elevated after P-body loss. Altogether, this study identifies a P-body-dependent repression activity that coordinates with known transcriptional repression programs to maintain a population of in vivo stem cells in a state primed for differentiation.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Diferenciação Celular/genética , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Intestinos , Mamíferos , Células-Tronco/metabolismo
4.
Genes Cells ; 26(4): 219-229, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33556205

RESUMO

In eukaryotes, specific DNA-protein structures called telomeres exist at linear chromosome ends. Telomere stability is maintained by a specific capping protein complex. This capping complex is essential for the inhibition of the DNA damage response (DDR) at telomeres and contributes to genome integrity. In Drosophila, the central factors of telomere capping complex are HOAP and HipHop. Furthermore, a DDR protein complex Mre11-Rad50-Nbs (MRN) is known to be important for the telomere association of HOAP and HipHop. However, whether MRN interacts with HOAP and HipHop, and the telomere recognition mechanisms of HOAP and HipHop are poorly understood. Here, we show that Nbs interacts with Mre11 and transports the Mre11-Rad50 complex from the cytoplasm to the nucleus. In addition, we report that HOAP interacts with both Mre11 and Nbs. The N-terminal region of HOAP is essential for its co-localization with HipHop. Finally, we reveal that Nbs interacts with the N-terminal region of HOAP.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Quebras de DNA de Cadeia Dupla , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Endodesoxirribonucleases/metabolismo , Telômero/metabolismo , Sequência de Aminoácidos , Animais , Núcleo Celular/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas de Drosophila/química , Ligação Proteica , Transporte Proteico
5.
Biomolecules ; 9(10)2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31546991

RESUMO

The spatial and temporal availability of cytokines, and the microenvironments this creates, is critical to tissue development and homeostasis. Creating concentration gradients in vitro using soluble proteins is challenging as they do not provide a self-sustainable source. To mimic the sustained cytokine secretion seen in vivo from the extracellular matrix (ECM), we encapsulated a cargo protein into insect virus-derived proteins to form nanoparticle co-crystals and studied the release of this cargo protein mediated by matrix metalloproteinase-2 (MMP-2) and MMP-8. Specifically, when nerve growth factor (NGF), a neurotrophin, was encapsulated into nanoparticles, its release was promoted by MMPs secreted by a PC12 neuronal cell line. When these NGF nanoparticles were spotted onto a cover slip to create a uniform circular field, movement and alignment of PC12 cells via their extended axons along the periphery of the NGF nanoparticle field was observed. Neural cell differentiation was confirmed by the expression of specific markers of tau, neurofilament, and GAP-43. Connections between the extended axons and the growth cones were also observed, and expression of connexin 43 was consistent with the formation of gap junctions. Extensions and connection of very fine filopodia occurred between growth cones. Our studies indicate that crystalline protein nanoparticles can be utilized to generate a highly stable cytokine gradient microenvironment that regulates the alignment and differentiation of nerve cells. This technique greatly simplifies the creation of protein concentration gradients and may lead to therapies for neuronal injuries and disease.


Assuntos
Citocinas/metabolismo , Metaloproteinases da Matriz/metabolismo , Fator de Crescimento Neural/farmacologia , Neurônios/citologia , Proteínas de Matriz de Corpos de Inclusão/genética , Reoviridae/fisiologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Preparações de Ação Retardada , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 8 da Matriz/metabolismo , Nanopartículas , Fator de Crescimento Neural/química , Fator de Crescimento Neural/genética , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Proteínas de Matriz de Corpos de Inclusão/metabolismo , Células PC12 , Tamanho da Partícula , Ratos , Reoviridae/genética , Reoviridae/metabolismo , Transdução de Sinais
6.
Cardiovasc Interv Ther ; 34(3): 234-241, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30343351

RESUMO

This study aims to elucidate 1-year clinical outcomes using this technique for patients with stage 4 or 5 advanced chronic kidney disease (CKD). Research has proven that imaging-guided percutaneous coronary intervention (PCI) reduces contrast volume significantly; however, only short-term clinical benefits have been reported. Minimum-contrast (MINICON) studies are based on the registry design pattern to enroll PCI results in patients with advanced CKD stage 4 or 5 comorbid with coronary artery disease. We excluded cases of emergency PCI or maintenance dialysis from this study. In this study, we compared the intravascular ultrasound (IVUS)-guided MINICON PCI group (n = 98) with the angiography-guided standard PCI group (n = 86). Enrollment of the MINICON studies started in 2006. Before 2012, IVUS-guided MINICON PCI was performed only in 14% (stage 1), but it was 100% after 2012 (stage 2). The enrollment finished in 2016. The IVUS-guided MINICON PCI group exhibited a significantly reduced contrast volume (22 ± 20 vs. 130 ± 105 mL; P < 0.0001) and contrast-induced acute kidney injury (CI-AKI; 2% vs. 15%; P = 0.001). The PCI success rate was similarly high (100% vs. 99%; P = 0.35). At 1 year (follow-up rate, 100%), we observed less induction of renal replacement therapy (RRT; 2.7% vs. 13.6%; P = 0.01), but all-cause mortality or myocardial infarction was similar in both groups. The IVUS-guided MINICON PCI reduces CI-AKI significantly and induction of RRT at 1 year in patients with stage 4 or 5 advanced CKD.


Assuntos
Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Intervenção Coronária Percutânea/métodos , Insuficiência Renal Crônica/complicações , Cirurgia Assistida por Computador/métodos , Ultrassonografia de Intervenção/métodos , Idoso , Doença da Artéria Coronariana/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Insuficiência Renal Crônica/diagnóstico , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
7.
Ecol Evol ; 8(19): 9590-9599, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30386559

RESUMO

Transposable elements not only can change genomic positions and disperse across the gene pool, but also can jump to another species through horizontal transmission. Of late, the P element, a DNA transposon in insects, was shown to cross the genetic boundary from Drosophila melanogaster to D. simulans in Europe around 2006. To understand the dynamics of transposable elements, especially in the early stages of invasion, we examined 63 lines of D. simulans from 11 natural populations in Japan established in 1976-2015. Based on PCR analyses, P elements were demonstrated to exist in Japan in 2008 and later. One copy of the full-length P element was identified and mapped to a site on chromosome 3 L in a genome. All of 18 copies of P elements examined shared "A" at the nucleotide position 2040, which is representative of the direct descendants of the original P element that invaded in D. simulans. We also found that some lines having P elements can induce intensive gonadal dysgenesis in D. simulans at 29°C. Our present results imply that P elements in D. simulans arrived at the east end of Asia just a few years later than or almost simultaneously to the initial invasion in Europe, Africa, and North America, suggesting a more astonishingly rapid spread than previously assumed.

8.
PLoS One ; 13(2): e0192096, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29420572

RESUMO

In order to investigate genetic impact of a large amount of radionuclides released by the Fukushima Dai-ichi Nuclear Power Plant accident in 2011, we surveyed 2,304 haploid genomes of Drosophila melanogaster collected in three localities in Fukushima in 2012 and 2013 for chromosomal inversions. No unique inversion was found in 298 genomes in 2012 and only two in 2,006 genomes in 2013. The observed frequencies were even lower than the long-term average frequency of unique inversions in Japan. The common cosmopolitan inversions were also examined in Fukushima, Kyoto, and Iriomote (Okinawa) in 2012. Among three samples in Fukushima, the flies in Iizaka, where environmental radiation level was the highest, showed the lowest frequency of In(2L)t, but the highest frequency of In(3R)P, contrary to the expectation of decreasing of their frequencies in higher polluted areas. These results suggest that, at this level of genetic analysis, Fukushima populations of D. melanogaster would not have been negatively impacted following the release of radionuclides. Transposable P-element mobility was not likely to induce DNA damage solely or synergistically with radioactivity, because their transposition activity was totally repressed in the Fukushima strains. However, it should be noted that, because of limitations in access to the exclusion zone, we could only sample the populations in areas of relatively low radioactive contamination (0.39-0.63 µSv/h). Therefore, the present study is likely to be underpowered to detect any effects that might be expected in heavily contaminated areas.


Assuntos
Inversão Cromossômica , Drosophila melanogaster/genética , Acidente Nuclear de Fukushima , Animais , Japão
9.
Hum Mol Genet ; 27(7): 1136-1149, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29360988

RESUMO

The continuity of life depends on mechanisms in the germline that ensure the integrity of the genome. The DNA damage response/checkpoint kinases ATM and ATR are essential signaling factors in the germline. However, it remains unknown how a downstream transducer, Checkpoint Kinase 1 (CHEK1 or CHK1), mediates signaling in the male germline. Here, we show that CHEK1 has distinct functions in both the mitotic and meiotic phases of the male germline in mice. In the mitotic phase, CHEK1 is required for the resumption of prospermatogonia proliferation after birth and the maintenance of spermatogonia. In the meiotic phase, we uncovered two functions for CHEK1: one is the stage-specific attenuation of DNA damage signaling on autosomes, and the other is coordination of meiotic stage progression. On autosomes, the loss of CHEK1 delays the removal of DNA damage signaling that manifests as phosphorylation of histone variant H2AX at serine 139 (γH2AX). Importantly, CHEK1 does not have a direct function in meiotic sex chromosome inactivation (MSCI), an essential event in male meiosis, in which ATR is a key regulator. Thus, the functions of ATR and CHEK1 are uncoupled in MSCI, in contrast to their roles in DNA damage signaling in somatic cells. Our study reveals stage-specific functions for CHEK1 that ensure the integrity of the male germline.


Assuntos
Quinase 1 do Ponto de Checagem/metabolismo , Dano ao DNA , Meiose , Transdução de Sinais , Espermatogônias/metabolismo , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quinase 1 do Ponto de Checagem/genética , Masculino , Camundongos , Camundongos Knockout , Espermatogônias/citologia
10.
Intern Med ; 56(7): 749-753, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28381739

RESUMO

Objectives The fractional flow reserve (FFR) is an index of the severity of coronary stenosis that has been clinically validated in several studies. The instantaneous wave-free ratio (iFR) and the resting distal coronary artery pressure/aortic pressure (Pd/Pa) are nonhyperemic pressure-derived indices of the severity of stenosis. This study sought to examine the diagnostic accuracy of the iFR and resting Pd/Pa with respect to hyperemic FFR. Methods Following an intracoronary injection of papaverine, the iFR, resting Pd/Pa, and FFR were continuously measured in 123 lesions in 103 patients with stable coronary disease. Results The iFR and resting Pd/Pa values were strongly correlated with the FFR (R=0.794, p<0.001, R=0.832, p<0.0001, respectively). A receiver operator curve (ROC) analysis revealed that the optimal iFR cut-off value for predicting an FFR of <0.80 was 0.89 (AUC 0.901, sensitivity 84.1%, specificity 80.0%, positive predictive value 69.8%, negative predictive value 90.0%, diagnostic accuracy 81.3%), while the optimal resting Pd/Pa cut-off value was 0.92 (AUC 0.925, sensitivity 90.9%, specificity 78.5%, positive predictive value 70.2%, negative predictive value 93.9%, diagnostic accuracy 82.9%). The lesions with an iFR value of ≤0.89 and a Pd/Pa value of ≤0.92 were defined as double-positive lesions, while the lesions with an iFR value of >0.89 and a Pd/Pa value of >0.92 were defined as double-negative lesions. In these 109 lesions, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 92.3%, 82.9%, 75.0%, 95.1%, and 86.2%, respectively. Conclusion This analysis demonstrated that the iFR and resting Pd/Pa were strongly correlated with the FFR and that the diagnostic accuracy of the iFR was similar to that of the resting Pd/Pa. The diagnostic accuracy can be improved with the use of both the iFR and the resting Pd/Pa.


Assuntos
Aorta/fisiologia , Pressão Arterial/fisiologia , Estenose Coronária/diagnóstico , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Idoso , Angiografia Coronária , Doença da Artéria Coronariana , Feminino , Coração , Humanos , Hiperemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Papaverina/farmacologia , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Vasodilatadores/farmacologia
11.
Intern Med ; 56(3): 253-257, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28154267

RESUMO

Objective Measuring the fractional flow reserve (FFR) requires the induction of coronary hyperemia, usually with adenosine, adenosine triphosphate (ATP), or papaverine. However, adenosine can induce rhythmic complications, and intracoronary boluses of papaverine that prolong the QT interval can cause ventricular tachycardia. Injection of contrast media, which is routinely performed to validate the FFR guidewire placement, also induces hyperemia and may be an alternative method of measuring the FFR. We evaluated the diagnostic accuracy of the FFR after contrast hyperemia (FFRcont) compared to FFR evaluated after intracoronary papaverine (FFRpp). Methods This study included 109 lesions in 93 patients (mean age 70.4±8.7 years) with stable coronary disease. The FFR was measured as follows: 1) baseline pressure value; 2) FFRcont after intracoronary contrast injection (iopamidol, 8 mL for left coronary artery [LCA] or 6 mL for right coronary artery [RCA]); 3) FFRpp after intracoronary injection of papaverine (12 mg for LCA or 8 mg for RCA). Results FFRcont values were strongly correlated with FFRpp (R=0.940, p<0.0001; FFRpp = FFRcont ×1.007-0.032). The best cut-off point in the receiver operator curve analysis for predicting a FFRpp <0.80 was 0.82 (area under the curve =0.980; sensitivity 95.1%, specificity 91.2%, positive predictive value 86.7%, negative predictive value 96.9%). Conclusion FFRcont is highly accurate for predicting FFRpp. An FFRcont threshold value of 0.82 provides excellent sensitivity and a negative predictive value. FFRcont is an alternative method of inducing hyperemia.


Assuntos
Meios de Contraste/administração & dosagem , Doença da Artéria Coronariana/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Hiperemia/induzido quimicamente , Vasodilatadores/administração & dosagem , Adenosina/administração & dosagem , Idoso , Angiografia Coronária , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Hiperemia/fisiopatologia , Infusões Intravenosas , Masculino , Papaverina/administração & dosagem , Valor Preditivo dos Testes , Índice de Gravidade de Doença
12.
Cell Rep ; 17(4): 1141-1157, 2016 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-27760317

RESUMO

Precise epigenetic regulation of the sex chromosomes is vital for the male germline. Here, we analyze meiosis in eight mouse models deficient for various DNA damage response (DDR) factors, including Fanconi anemia (FA) proteins. We reveal a network of FA and DDR proteins in which FA core factors FANCA, FANCB, and FANCC are essential for FANCD2 foci formation, whereas BRCA1 (FANCS), MDC1, and RNF8 are required for BRCA2 (FANCD1) and SLX4 (FANCP) accumulation on the sex chromosomes during meiosis. In addition, FA proteins modulate distinct histone marks on the sex chromosomes: FA core proteins and FANCD2 regulate H3K9 methylation, while FANCD2 and RNF8 function together to regulate H3K4 methylation independently of FA core proteins. Our data suggest that RNF8 integrates the FA-BRCA pathway. Taken together, our study reveals distinct functions for FA proteins and illuminates the male sex chromosomes as a model to dissect the function of the FA-BRCA pathway.


Assuntos
Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Histonas/metabolismo , Meiose , Processamento de Proteína Pós-Traducional , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Proteínas de Ciclo Celular , Quebras de DNA de Cadeia Dupla , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lisina/metabolismo , Masculino , Metilação , Camundongos , Rad51 Recombinase/metabolismo , Recombinação Genética/genética , Cromossomos Sexuais/metabolismo , Fatores de Tempo
13.
Int J Cardiol ; 222: 391-395, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27500767

RESUMO

BACKGROUND: Generally, newly progressed coronary lesions (NPCLs) are considered to be composed of lipid-rich plaques. In case of vulnerable plaque rupture, they may quickly become culprit lesions responsible for acute coronary syndromes. METHODS: Between September 2011 and September 2015, 2034 patients underwent scheduled follow-up coronary angiography (CAG) after percutaneous coronary intervention (PCI) in Tsuchiya General Hospital. Patients with NPCLs found by CAG during the follow-up period were evaluated by optical coherence tomography (OCT). NPCLs were defined as the lesions with less than 50% diameter stenosis, which progressed to more than 75% diameter stenosis within 3years after the previous CAG. Patients with restenosis after PCI were excluded. We compared OCT findings of NPCLs between symptomatic and asymptomatic patients. RESULTS: The follow-up CAG showed NPCLs in 64 patients (3.2%). OCT revealed fibrous plaque in 42 patients (65.6%) and thin-cap fibroatheroma in one patient. Thirteen patients had chest symptoms for one month before CAG and the remaining 51 patients were asymptomatic. The prevalence of fibrous plaque and intimal disruption or plaque rupture were not significantly different between symptomatic and asymptomatic patients (61.5% vs. 66.7%, p=0.752 and 30.8% vs. 11.8%, p=0.213, respectively). However, thrombi were more frequently observed in symptomatic patients (61.5% vs. 13.7%, p<0.001). CONCLUSIONS: The majority of NPCLs found in asymptomatic patients at follow-up CAG were not vulnerable; however, those found in symptomatic patients might be vulnerable. In clinical practice, NPCLs found in asymptomatic patients should be evaluated for functional severity of stenosis in order to determine the need for coronary revascularization.


Assuntos
Doenças Assintomáticas , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Progressão da Doença , Tomografia de Coerência Óptica/métodos , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas/epidemiologia , Angiografia Coronária/normas , Doença da Artéria Coronariana/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia de Coerência Óptica/normas
14.
Genes Cells ; 20(11): 902-14, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26334932

RESUMO

Post-translational modification of the histone plays important roles in epigenetic regulation of various biological processes. Among the identified histone methyltransferases (HMTases), G9a is a histone H3 Lys 9 (H3K9)-specific example active in euchromatic regions. Drosophila G9a (dG9a) has been reported to feature H3K9 dimethylation activity in vivo. Here, we show that the time required for hatching of a homozygous dG9a null mutant and heteroallelic combination of dG9a null mutants is delayed, suggesting that dG9a is at least partially responsible for progression of embryogenesis. Immunocytochemical analyses of the wild-type and the dG9a null mutant flies indicated that dG9a localizes in cytoplasm up to nuclear division cycle 7 where it is likely responsible for di-methylation of nucleosome-free H3K9. From cycles 8-11, dG9a moves into the nucleus and is responsible for di-methylating H3K9 in nucleosomes. RNA-sequence analysis utilizing early wild-type and dG9a mutant embryos showed that dG9a down-regulates expression of genes responsible for embryogenesis. RNA fluorescent in situ hybridization analysis further showed temporal and spatial expression patterns of these mRNAs did not significantly change in the dG9a mutant. These results indicate that dG9a controls transcription levels of some zygotic genes without changing temporal and spatial expression patterns of the transcripts of these genes.


Assuntos
Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Animais , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Desenvolvimento Embrionário/genética , Epigênese Genética , Epigenômica , Histona Metiltransferases , Histonas/metabolismo , Metilação , Dados de Sequência Molecular , Processamento de Proteína Pós-Traducional , Transcriptoma
15.
Hum Mol Genet ; 24(18): 5234-49, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26123487

RESUMO

Fanconi anemia (FA) is a recessive X-linked and autosomal genetic disease associated with bone marrow failure and increased cancer, as well as severe germline defects such as hypogonadism and germ cell depletion. Although deficiencies in FA factors are commonly associated with germ cell defects, it remains unknown whether the FA pathway is involved in unique epigenetic events in germ cells. In this study, we generated Fancb mutant mice, the first mouse model of X-linked FA, and identified a novel function of the FA pathway in epigenetic regulation during mammalian gametogenesis. Fancb mutant mice were infertile and exhibited primordial germ cell (PGC) defects during embryogenesis. Further, Fancb mutation resulted in the reduction of undifferentiated spermatogonia in spermatogenesis, suggesting that FANCB regulates the maintenance of undifferentiated spermatogonia. Additionally, based on functional studies, we dissected the pathway in which FANCB functions during meiosis. The localization of FANCB on sex chromosomes is dependent on MDC1, a binding partner of H2AX phosphorylated at serine 139 (γH2AX), which initiates chromosome-wide silencing. Also, FANCB is required for FANCD2 localization during meiosis, suggesting that the role of FANCB in the activation of the FA pathway is common to both meiosis and somatic DNA damage responses. H3K9me2, a silent epigenetic mark, was decreased on sex chromosomes, whereas H3K9me3 was increased on sex chromosomes in Fancb mutant spermatocytes. Taken together, these results indicate that FANCB functions at critical stages of germ cell development and reveal a novel function of the FA pathway in the regulation of H3K9 methylation in the germline.


Assuntos
Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Genes Essenciais , Células Germinativas/metabolismo , Histonas/metabolismo , Meiose/genética , Cromossomos Sexuais , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas de Ciclo Celular , Diferenciação Celular/genética , Epigênese Genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Feminino , Fertilidade/genética , Regulação da Expressão Gênica , Loci Gênicos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Metilação , Camundongos , Camundongos Knockout , Modelos Biológicos , Mutação , Transporte Proteico , Recombinação Genética , Espermatogônias/citologia , Espermatogônias/metabolismo
16.
J Cell Biol ; 205(5): 663-75, 2014 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-24914237

RESUMO

During meiosis, DNA damage response (DDR) proteins induce transcriptional silencing of unsynapsed chromatin, including the constitutively unsynapsed XY chromosomes in males. DDR proteins are also implicated in double strand break repair during meiotic recombination. Here, we address the function of the breast cancer susceptibility gene Brca1 in meiotic silencing and recombination in mice. Unlike in somatic cells, in which homologous recombination defects of Brca1 mutants are rescued by 53bp1 deletion, the absence of 53BP1 did not rescue the meiotic failure seen in Brca1 mutant males. Further, BRCA1 promotes amplification and spreading of DDR components, including ATR and TOPBP1, along XY chromosome axes and promotes establishment of pericentric heterochromatin on the X chromosome. We propose that BRCA1-dependent establishment of X-pericentric heterochromatin is critical for XY body morphogenesis and subsequent meiotic progression. In contrast, BRCA1 plays a relatively minor role in meiotic recombination, and female Brca1 mutants are fertile. We infer that the major meiotic role of BRCA1 is to promote the dramatic chromatin changes required for formation and function of the XY body.


Assuntos
Proteína BRCA1/fisiologia , Dano ao DNA , Heterocromatina/genética , Meiose , Recombinação Genética , Cromossomo X/genética , Alelos , Animais , Pareamento Cromossômico , Cromossomos/metabolismo , Éxons , Feminino , Deleção de Genes , Inativação Gênica , Masculino , Camundongos , Mutação , Fenótipo , Espermatogênese
17.
Thromb Res ; 132(1): 56-62, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23522855

RESUMO

INTRODUCTION: Aspirin inhibits both the cyclooxygenase (COX)-1-dependent production of thromboxane A2 (TXA2) in platelets and COX-2-dependent production of anti-aggregatory prostaglandin I2 (PGI2) in vessel walls, resulting in "aspirin dilemma." Our objective is to investigate whether ASP6537 can overcome aspirin dilemma and exert a potent antithrombotic effect without a concurrent ulcerogenic effect. METHODS: We evaluated the inhibitory effects of ASP6537 on recombinant human COX-1 (rhCOX-1) and rhCOX-2 activities using a COX-1/2 selectivity test. To determine whether ASP6537 induces aspirin dilemma, we examined the effects of ASP6537 on in vitro TXA2 and PGI2 metabolite production from platelets and isolated aorta of guinea pigs, and on plasma concentrations of TXA2 and PGI2 metabolites in aged rats. Finally, we evaluated the antithrombotic effects and ulcerogenic activity of ASP6537 using an electrically induced carotid arterial thrombosis model and a gastric ulcer model in guinea pigs. RESULTS: The IC50 ratios of rhCOX-2 to rhCOX-1 for ASP6537 and aspirin were >142,000 and 1.63 fold, respectively. ASP6537 inhibited TXA2 production more selectively than aspirin in in vitro and in vivo TXA2/PGI2 production studies. ASP6537 exerted a significant antithrombotic effect at ≥3 mg/kg, while aspirin tended to inhibit thrombosis at 300 mg/kg but it was not statistically significant. Further, ASP6537 did not induce ulcer formation at 100 mg/kg, whereas aspirin exhibited an ulcerogenic effect at doses of ≥100 mg/kg. CONCLUSIONS: ASP6537 functions as a highly selective COX-1 inhibitor with a superior ability to aspirin for normalizing TXA2/PGI2 balance, and exerts antithrombotic effect without ulcerogenic effect.


Assuntos
Aspirina/uso terapêutico , Trombose das Artérias Carótidas/tratamento farmacológico , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase/uso terapêutico , Fibrinolíticos/uso terapêutico , Triazóis/uso terapêutico , Animais , Aspirina/efeitos adversos , Aspirina/farmacologia , Trombose das Artérias Carótidas/enzimologia , Inibidores de Ciclo-Oxigenase/efeitos adversos , Inibidores de Ciclo-Oxigenase/farmacologia , Epoprostenol/metabolismo , Epoprostenol/urina , Fibrinolíticos/efeitos adversos , Fibrinolíticos/farmacologia , Cobaias , Humanos , Masculino , Prostaglandinas/sangue , Prostaglandinas/metabolismo , Ratos , Estômago/efeitos dos fármacos , Triazóis/efeitos adversos , Triazóis/farmacologia , Úlcera/induzido quimicamente
18.
Heart Vessels ; 28(1): 7-11, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22045153

RESUMO

Aliskiren is a novel blood pressure-lowering agent acting as an oral direct renin inhibitor. We evaluated the effects of aliskiren on the fibrinolytic system in patients with coronary artery disease who were receiving angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs). We studied 17 patients with coronary artery disease whose systolic blood pressure was more than 130 mmHg despite treatment with ACEIs or ARBs. Aliskiren (150 mg) was added to ACEIs or ARBs, and was continued for 6 weeks. Aliskiren significantly decreased systolic blood pressure (140 ± 6-128 ± 8 mmHg, P < 0.001) and plasma renin activity (1.8 ± 2.3-0.6 ± 0.9 ng/ml/h, P < 0.01) after 6 weeks. However, it did not affect plasminogen activator inhibitor-1 (28.8 ± 14.5-30.6 ± 13.6 ng/ml, P = 0.84), fibrinogen (305 ± 72 vs 301 ± 71 mg/dl, P = 0.33), or D-dimer (0.49 ± 0.24-0.51 ± 0.28 µg/ml, P = 0.70) levels. Our data suggested that patients receiving ACEIs or ARBs would not be expected to have any changes in biomarkers of the fibrinolytic system with additional pharmacologic inhibition of the renin-angiotensin-aldosterone system.


Assuntos
Amidas/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Doença da Artéria Coronariana/tratamento farmacológico , Fibrinólise/efeitos dos fármacos , Fumaratos/administração & dosagem , Idoso , Pressão Sanguínea/efeitos dos fármacos , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/fisiopatologia , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Renina/antagonistas & inibidores , Resultado do Tratamento
19.
Heart Vessels ; 28(1): 34-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22187148

RESUMO

Residual risk of cardiovascular events after treatment with stain might be explained in part because patients have low levels of n-3 polyunsaturated fatty acids (PUFA). We examined how lipid-lowering therapy with strong statin affected serum PUFA levels in patients with coronary artery disease. The study population consisted of 46 patients with coronary artery disease whose low-density lipoprotein (LDL) cholesterol was more than 100 mg/dl. Lipid-lowering therapy was performed with a strong statin including atorvastatin (n = 22), rosuvastatin (n = 9) or pitavastatin (n = 15). Serum PUFA levels were determined by gas chromatography. The treatment with strong statin decreased the sum of dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA) levels (195 ± 41 to 184 ± 44 µg/ml, P < 0.05) as well as the sum of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels (233 ± 71 to 200 ± 72 µg/ml, P < 0.001). These effects of strong statin resulted in a significant decrease in ratio of the sum of EPA and DHA levels to the sum of DGLA and AA levels (1.20 ± 0.27 to 1.10 ± 0.35, P < 0.05). The percent decrease in the LDL cholesterol level correlated significantly with that in the sum of EPA and DHA levels (r = 0.38, P < 0.01). In conclusion, our results showed that lipid-lowering therapy with strong statin mainly reduced n-3 PUFAs in proportion to the decrease in the LDL cholesterol level in patients with coronary artery disease.


Assuntos
Doença da Artéria Coronariana/tratamento farmacológico , Ácidos Graxos Insaturados/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipolipemiantes/uso terapêutico , Lipídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Doença da Artéria Coronariana/sangue , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
20.
PLoS One ; 7(11): e48431, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23133633

RESUMO

Sensory input is essential for the normal development of sensory centers in the brain, such as the somatosensory, visual, auditory, and olfactory systems. Visual deprivation during a specific developmental stage, called the critical period, results in severe and irreversible functional impairments in the primary visual cortex. Olfactory deprivation in the early postnatal period also causes significant developmental defects in the olfactory bulb, the primary center for olfaction. Olfactory bulb interneurons are continuously generated from neural stem cells in the ventricular-subventricular zone, suggesting that the olfactory system has plasticity even in adulthood. Here, we investigated the effect of transient neonatal olfactory deprivation on the addition of interneurons to the glomerular layer of the adult mouse olfactory bulb. We found that the addition of one subtype of interneurons was persistently inhibited even after reopening the naris. BrdU pulse-chase experiments revealed that the neonatal olfactory deprivation predominantly affected an early phase in the maturation of this neuronal subtype in the olfactory bulb. Subjecting the mice to odor stimulation for 6 weeks after naris reopening resulted in significant recovery from the histological and functional defects caused by the olfactory deprivation. These results suggest that a subtype-specific critical period exists for olfactory bulb neurogenesis, but that this period is less strict and more plastic compared with the critical periods for other systems. This study provides new insights into the mechanisms of postnatal neurogenesis and a biological basis for the therapeutic effect of olfactory training.


Assuntos
Neurogênese/fisiologia , Bulbo Olfatório/patologia , Olfato/fisiologia , Animais , Bromodesoxiuridina/farmacologia , Núcleo Celular/metabolismo , Imuno-Histoquímica/métodos , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Odorantes , Privação Sensorial/fisiologia , Córtex Visual/fisiologia
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