Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Med Primatol ; 52(3): 163-169, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36973936

RESUMO

BACKGROUND: Melatonin is a multifunctional hormone synthesized in the pineal gland and peripheral reproductive tissues that regulates many biological processes. There is increasing evidence for a role of melatonin in oocyte maturation and embryonic development in various mammals. However, no study has reported evidence for the existence of melatonergic system, such as melatonin synthesis enzymes, melatonin membrane receptors, or melatonin binding sites in non-human primate cumulus-oocyte complexes (COCs). METHODS: Reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry were performed to detect transcripts and proteins of the rate-limiting enzyme in melatonin synthesis (arylalkylamine N-acetyltransferase, AANAT), melatonin membrane receptors (MT1 and MT2), and a melatonin binding site (NRH: quinone oxidoreductase 2, NQO2) in cynomolgus monkey COCs. RESULTS: RT-PCR analyses revealed the presence of AANAT, MT1, MT2, and NQO2 transcripts in granulosa cells, germinal vesicle (GV)- and metaphase II (MII)-stage cumulus cells, and oocytes. Immunocytochemistry revealed the presence of AANAT, MT1, MT2, and NQO2 proteins in GV- and MII-stage COCs. CONCLUSIONS: Our results provide the first evidence for the existence of the rate-limiting enzyme required for melatonin synthesis, melatonin membrane receptors, and a melatonin binding site in non-human primate COCs.


Assuntos
Melatonina , Feminino , Animais , Macaca fascicularis/metabolismo , Melatonina/metabolismo , Oócitos , Receptores de Melatonina/metabolismo , Células do Cúmulo/metabolismo , Mamíferos/metabolismo
2.
Biochem J ; 477(23): 4581-4597, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33155636

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disease associated with the accumulation of amyloid-beta oligomers (AßO). Recent studies have demonstrated that mitochondria-specific autophagy (mitophagy) contributes to mitochondrial quality control by selectively eliminating the dysfunctional mitochondria. Mitochondria motility, which is regulated by Miro1, is also associated with neuronal cell functions. However, the role played by Miro1 in the mitophagy mechanism, especially relative to AßO and neurodegenerative disorders, remains unknown. In this study, AßO induced mitochondrial dysfunction, enhanced Parkin-mediated mitophagy, and reduced mitochondrial quantities in hippocampal neuronal cells (HT-22 cells). We demonstrated that AßO-induced mitochondrial fragmentation could be rescued to the elongated mitochondrial form and that mitophagy could be mitigated by the stable overexpression of Miro1 or by pretreatment with N-acetylcysteine (NAC)-a reactive oxygen species (ROS) scavenger-as assessed by immunocytochemistry. Moreover, using time-lapse imaging, under live cell-conditions, we verified that mitochondrial motility was rescued by the Miro1 overexpression. Finally, in hippocampus from amyloid precursor protein (APP)/presenilin 1 (PS1)/Tau triple-transgenic mice, we noted that the co-localization between mitochondria and LC3B puncta was increased. Taken together, these results indicated that up-regulated ROS, induced by AßO, increased the degree of mitophagy and decreased the Miro1 expression levels. In contrast, the Miro1 overexpression ameliorated AßO-mediated mitophagy and increased the mitochondrial motility. In AD model mice, AßO induced mitophagy in the hippocampus. Thus, our results would improve our understanding of the role of mitophagy in AD toward facilitating the development of novel therapeutic agents for the treatment of AßO-mediated diseases.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Mitofagia , Neurônios/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Animais , Linhagem Celular , Humanos , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas rho de Ligação ao GTP/genética
3.
BMC Evol Biol ; 20(1): 66, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503430

RESUMO

BACKGROUND: Alternative splicing (AS) generates various transcripts from a single gene and thus plays a significant role in transcriptomic diversity and proteomic complexity. Alu elements are primate-specific transposable elements (TEs) and can provide a donor or acceptor site for AS. In a study on TE-mediated AS, we recently identified a novel AluSz6-exonized ACTR8 transcript of the crab-eating monkey (Macaca fascicularis). In the present study, we sought to determine the molecular mechanism of AluSz6 exonization of the ACTR8 gene and investigate its evolutionary and functional consequences in the crab-eating monkey. RESULTS: We performed RT-PCR and genomic PCR to analyze AluSz6 exonization in the ACTR8 gene and the expression of the AluSz6-exonized transcript in nine primate samples, including prosimians, New world monkeys, Old world monkeys, and hominoids. AluSz6 integration was estimated to have occurred before the divergence of simians and prosimians. The Alu-exonized transcript obtained by AS was lineage-specific and expressed only in Old world monkeys and apes, and humans. This lineage-specific expression was caused by a single G duplication in AluSz6, which provides a new canonical 5' splicing site. We further identified other alternative transcripts that were unaffected by the AluSz6 insertion. Finally, we observed that the alternative transcripts were transcribed into new isoforms with C-terminus deletion, and in silico analysis showed that these isoforms do not have a destructive function. CONCLUSIONS: The single G duplication in the TE sequence is the source of TE exonization and AS, and this mutation may suffer a different fate of ACTR8 gene expression during primate evolution.


Assuntos
Regulação da Expressão Gênica , Proteínas dos Microfilamentos/genética , Mutação , Primatas/genética , Processamento Alternativo , Elementos Alu/genética , Animais , Elementos de DNA Transponíveis/genética , Evolução Molecular , Éxons/genética , Humanos
4.
Mol Cell Biochem ; 468(1-2): 97-109, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32185676

RESUMO

Obesity was originally considered a disease endemic to developed countries but has since emerged as a global health problem. Obesity is characterized by abnormal or excessive lipid accumulation (World Health Organization, WHO) resulting from pre-adipocyte differentiation (adipogenesis). The endoplasmic reticulum (ER) produces proteins and cholesterol and shuttles these compounds to their target sites. Many studies have implicated ER stress, indicative of ER dysfunction, in adipogenesis. Reactive oxygen species (ROS) are also known to be involved in pre-adipocyte differentiation. Prx4 specific to the ER lumen exhibits ROS scavenging activity, and we thereby focused on ER-specific Prx4 in tracking changes in adipocyte differentiation and lipid accumulation. Overexpression of Prx4 reduced ER stress and suppressed lipid accumulation by regulating adipogenic gene expression during adipogenesis. Our results demonstrate that Prx4 inhibits ER stress, lowers ROS levels, and attenuates pre-adipocyte differentiation. These findings suggested enhancing the activity of Prx4 may be helpful in the treatment of obesity; the data also support the development of new therapeutic approaches to obesity and obesity-related metabolic disorders.


Assuntos
Adipócitos/metabolismo , Adipogenia/genética , Estresse do Retículo Endoplasmático/genética , Insulina/farmacologia , Obesidade/metabolismo , Peroxirredoxinas/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/enzimologia , Adipogenia/efeitos dos fármacos , Animais , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Metabolismo dos Lipídeos/genética , Camundongos , Obesidade/genética , Peroxirredoxinas/genética , Espécies Reativas de Oxigênio/metabolismo
5.
Cell Biol Int ; 44(10): 2086-2093, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32639620

RESUMO

Reactive oxygen species (ROS) act as signaling molecules to regulate various cell functions. Numerous studies have demonstrated ROS to be essential for the differentiation of adipocytes. Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant enzymes in mammalian cells. Prx2 is present in the cytoplasm and cell membranes and demonstrates ROS scavenging activity. We focused on Prx2 involvement in regulating adipogenesis and lipid accumulation and demonstrated that Prx2 expression was upregulated during adipocyte differentiation. In addition, the silencing of Prx2 (shPrx2) inhibited adipogenesis by modulating adipogenic gene expression, and cell death was enhanced via increased ROS production in shPrx2-3T3-L1 cells. These results demonstrate that shPrx2 triggers adipocyte cell death and weakens adipocyte function via ROS production. Taken together, our data suggest the participation of Prx2 in adipocyte function and differentiation. Our results also imply that the downregulation of Prx2 activity could help prevent obesity. Overall, findings support the development of ROS-based therapeutic solutions for the treatment of obesity and obesity-related metabolic disorders.


Assuntos
Adipócitos , Adipogenia , Tecido Adiposo Branco/citologia , Metabolismo dos Lipídeos , Peroxirredoxinas/fisiologia , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Diferenciação Celular , Camundongos , Obesidade/metabolismo , Obesidade/patologia , Espécies Reativas de Oxigênio/metabolismo
6.
BMC Evol Biol ; 19(1): 196, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666001

RESUMO

BACKGROUND: The BLOC1S2 gene encodes the multifunctional protein BLOS2, a shared subunit of two lysosomal trafficking complexes: i) biogenesis of lysosome-related organelles complex-1 and i) BLOC-1-related complex. In our previous study, we identified an intriguing unreported transcript of the BLOC1S2 gene that has a novel exon derived from two transposable elements (TEs), MIR and AluSp. To investigate the evolutionary footprint and molecular mechanism of action of this transcript, we performed PCR and RT-PCR experiments and sequencing analyses using genomic DNA and RNA samples from humans and various non-human primates. RESULTS: The results showed that the MIR element had integrated into the genome of our common ancestor, specifically in the BLOC1S2 gene region, before the radiation of all primate lineages and that the AluSp element had integrated into the genome of our common ancestor, fortunately in the middle of the MIR sequences, after the divergence of Old World monkeys and New World monkeys. The combined MIR and AluSp sequences provide a 3' splice site (AG) and 5' splice site (GT), respectively, and generate the Old World monkey-specific transcripts. Moreover, branch point sequences for the intron removal process are provided by the MIR and AluSp combination. CONCLUSIONS: We show for the first time that sequential integration into the same location and sequence divergence events of two different TEs generated lineage-specific transcripts through sequence collaboration during primate evolution.


Assuntos
Processamento Alternativo , Elementos de DNA Transponíveis , Evolução Molecular , Primatas/genética , Elementos Alu , Animais , Evolução Biológica , Cercopithecidae/classificação , Cercopithecidae/genética , Éxons , Humanos , Íntrons , MicroRNAs/genética , Especificidade de Órgãos , Platirrinos/classificação , Platirrinos/genética , Primatas/classificação , Proteínas/genética , Transcriptoma
7.
Toxicol Appl Pharmacol ; 384: 114797, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676320

RESUMO

Many studies report that cadmium chloride (CdCl2)-induces oxidative stress is associated with male reproductive damage in the testes. CdCl2 also induces mitochondrial fission by increasing dynamin-related protein 1 (Drp1) expression as well as the mitochondria-dependent apoptosis pathway by extracellular signal-regulated kinase (ERK) activation. However, it remains unclear whether mechanisms linked to the mitochondrial damage signal via CdCl2-induced mitogen-activated protein kinases (MAPK) cause damage to spermatocytes. In this study, increased intracellular and mitochondrial reactive oxygen species (ROS) levels, mitochondrial membrane potential (∆Ψm) depolarization, and mitochondrial fragmentation and swelling were observed at 5 µM of CdCl2 exposure, resulting in increased apoptotic cell death. Moreover, CdCl2-induced cell death is closely associated with the ERK/Drp1/p38 signaling axis. Interestingly, SB203580, a p38 inhibitor, effectively prevented CdCl2-induced apoptotic cell death by reducing ∆Ψm depolarization and intracellular and mitochondrial ROS levels. Knockdown of Drp1 expression diminished CdCl2-induced mitochondrial deformation and ROS generation and protected GC-2spd cells from apoptotic cell death. In addition, electron microscopy showed that p38 inhibition reduced CdCl2-induced mitochondrial interior damage more effectively than N-acetyl-L-cysteine (NAC), an ROS scavenger; ERK inhibition; or Drp1 knockdown. Therefore, these results demonstrate that inhibition of p38 activity prevents CdCl2-induced apoptotic GC-2spd cell death by reducing depolarization of mitochondrial membrane potential and mitochondrial ROS levels via ERK phosphorylation in a signal pathway different from the CdCl2-induced ERK/Drp1/p38 axis and suggest a therapeutic strategy for CdCl2-induced male infertility.


Assuntos
Cloreto de Cádmio/toxicidade , Imidazóis/farmacologia , Infertilidade Masculina/tratamento farmacológico , Piridinas/farmacologia , Espermatócitos/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Dinaminas/genética , Dinaminas/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Imidazóis/uso terapêutico , Infertilidade Masculina/induzido quimicamente , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Microscopia Eletrônica , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Mitocôndrias/ultraestrutura , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Piridinas/uso terapêutico , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Espermatócitos/citologia , Espermatócitos/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
8.
Reproduction ; 158(6): 543-554, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31652418

RESUMO

The developmental competence of in vitro-matured oocytes is still lower than that of the in vivo-matured oocytes due to precocious meiotic resumption and inappropriate cytoplasmic maturation. Although numerous efforts have been attempted to accomplish better in vitro maturation (IVM) condition, only limited progress has been achieved. Thus, a current study was conducted to examine the effects of 6-diazo-5-oxo-l-norleucine (DON, an inhibitor of hyaluronan synthesis) during the first half period of IVM on nuclear/cytoplasmic maturation of porcine oocytes and subsequent embryonic development. Based on the observation of the nucleus pattern, metaphase II (MII) oocyte production rate in 1 µM DON group was significantly higher than other groups at 44 h of IVM. The 1 µM of DON was suggested to be optimal for porcine IVM and was therefore used for further investigation. Meiotic arrest effect of DON was maximal at 6 h of IVM, which was supported by the maintenance of significantly higher intra-oocyte cAMP level. In addition, increased pERK1/2 levels and clear rearrangement of cortical granules in membrane of MII oocytes matured with DON provided the evidence for balanced meiosis progression between nuclear and cytoplasmic maturation. Subsequently, DON significantly improved blastocyst formation rate, total cell numbers, and cellular survival in blastocysts after parthenogenetic activation, in vitro fertilization, and somatic cell nuclear transfer. Altogether, our results showed for the first time that 1 µM DON can be used to increase the yield of developmentally competent MII oocytes by synchronizing nuclear/cytoplasmic maturation, and it subsequently improves embryo developmental competence.


Assuntos
Núcleo Celular/fisiologia , Citoplasma/fisiologia , Diazo-Oxo-Norleucina/farmacologia , Desenvolvimento Embrionário/efeitos dos fármacos , Técnicas de Maturação in Vitro de Oócitos/veterinária , Meiose , Oócitos/citologia , Animais , Antibióticos Antineoplásicos/farmacologia , Núcleo Celular/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Feminino , Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/métodos , Técnicas de Transferência Nuclear , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Gravidez , Suínos
9.
Cogn Behav Neurol ; 32(3): 172-178, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31517700

RESUMO

BACKGROUND: Mixed reality (MR) technology, which combines the best features of augmented reality and virtual reality, has recently emerged as a promising tool in cognitive rehabilitation therapy. OBJECTIVE: To investigate the effectiveness of an MR-based cognitive training system for individuals with mild cognitive impairment (MCI). METHODS: Twenty-one individuals aged 65 years and older who had been diagnosed with MCI were recruited for this study and were divided into two groups. Participants in the MR group (n=10, aged 70.5±4.2 years) received 30 minutes of training 3 times a week for 6 weeks using a newly developed MR-based cognitive training system. Participants in the control group (n=11, aged 72.6±5.3 years) received the same amount of training using a conventional computer-assisted cognitive training system. Both groups took the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) both before and after intervention. To determine the effect of the intervention on cognitive function, we compared the difference in each group's CERAD-K scores. RESULTS: There was a statistically significant interaction between intervention (MR group vs control group) and time (before vs after intervention) as assessed by the Constructional Recall Test. The individuals with MCI who participated in the MR training showed significantly improved performance in visuospatial working memory compared with the individuals with MCI who participated in the conventional training. CONCLUSION: An MR-based cognitive training system can be used as a cognitive training tool to improve visuospatial working memory in individuals with MCI.


Assuntos
Transtornos Cognitivos/diagnóstico , Testes Neuropsicológicos/normas , Idoso , Idoso de 80 Anos ou mais , Realidade Aumentada , Disfunção Cognitiva/diagnóstico , Feminino , Humanos , Masculino , Projetos Piloto , Realidade Virtual
10.
J Korean Med Sci ; 34(8): e66, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833883

RESUMO

BACKGROUND: Gross anatomy and sectional anatomy of a monkey should be known by students and researchers of veterinary medicine and medical research. However, materials to learn the anatomy of a monkey are scarce. Thus, the objective of this study was to produce a Visible Monkey data set containing cross sectional images, computed tomographs (CTs), and magnetic resonance images (MRIs) of a monkey whole body. METHODS: Before and after sacrifice, a female rhesus monkey was used for 3 Tesla MRI and CT scanning. The monkey was frozen and sectioned at 0.05 mm intervals for the head region and at 0.5 mm intervals for the rest of the body using a cryomacrotome. Each sectioned surface was photographed using a digital camera to obtain horizontal sectioned images. Segmentation of sectioned images was performed to elaborate three-dimensional (3D) models of the skin and brain. RESULTS: A total of 1,612 horizontal sectioned images of the head and 1,355 images of the remaining region were obtained. The small pixel size (0.024 mm × 0.024 mm) and real color (48 bits color) of these images enabled observations of minute structures. CONCLUSION: Due to small intervals of these images, continuous structures could be traced completely. Moreover, 3D models of the skin and brain could be used for virtual dissections. Sectioned images of this study will enhance the understanding of monkey anatomy and foster further studies. These images will be provided to any requesting researcher free of charge.


Assuntos
Macaca mulatta/anatomia & histologia , Imageamento por Ressonância Magnética , Anatomia Transversal , Animais , Feminino , Cabeça/anatomia & histologia , Cabeça/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X , Imagem Corporal Total
11.
BMC Genomics ; 19(1): 267, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29669513

RESUMO

BACKGROUND: The characterization of genomic or epigenomic variation in human and animal models could provide important insight into pathophysiological mechanisms of various diseases, and lead to new developments in disease diagnosis and clinical intervention. The African green monkey (AGM; Chlorocebus aethiops) and cynomolgus monkey (CM; Macaca fascicularis) have long been considered important animal models in biomedical research. However, non-human primate-specific methods applicable to epigenomic analyses in AGM and CM are lacking. The recent development of methyl-capture sequencing (MC-seq) has an unprecedented advantage of cost-effectiveness, and further allows for extending the methylome coverage compared to conventional sequencing approaches. RESULTS: Here, we used a human probe-designed MC-seq method to assay DNA methylation in DNA obtained from 13 CM and three AGM blood samples. To effectively adapt the human probe-designed target region for methylome analysis in non-human primates, we redefined the target regions, focusing on regulatory regions and intragenic regions with consideration of interspecific sequence homology and promoter region variation. Methyl-capture efficiency was controlled by the sequence identity between the captured probes based on the human reference genome and the AGM and CM genome sequences, respectively. Using reasonable guidelines, 56 and 62% of the human-based capture probes could be effectively mapped for DNA methylome profiling in the AGM and CM genome, respectively, according to numeric global statistics. In particular, our method could cover up to 89 and 87% of the regulatory regions of the AGM and CM genome, respectively. CONCLUSIONS: Use of human-based MC-seq methods provides an attractive, cost-effective approach for the methylome profiling of non-human primates at the single-base resolution level.


Assuntos
Chlorocebus aethiops , Metilação de DNA , Epigenômica/métodos , Macaca fascicularis , Animais , Genoma Humano/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
12.
Biochim Biophys Acta ; 1858(12): 3017-3023, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27664498

RESUMO

Cholesterol is an important cell membrane component and has been used as co-lipid for cationic liposome to enhance gene delivery. However, the role of cholesterol in transfection efficiency has not been fully understood. In this study, transfection efficiency of liposome was measured after cholesterol was added to the cell culture medium. As a result, addition of cholesterol increased transfection efficiency of several liposomes consisting of different lipid components in various cells (AGS, CHO, COS7 and, MCF7). Furthermore, treatment of cells with cholesterol modulating drugs, imipramine and U18666A, also increased transfection efficiency of liposomes. To elucidate the role of added cholesterol in gene transfer, endocytotic mechanism was studied and also revealed that adding cholesterol in culture media induced participation of caveolae-mediated endocytosis and micropinocytosis in CHO cell. Therefore, the results of this work suggest that modulation of intracellular cholesterol can be an important method to enhance gene delivery.


Assuntos
Colesterol/farmacologia , Técnicas de Transferência de Genes , Lipossomos/metabolismo , Androstenos/farmacologia , Animais , Células CHO , Células COS , Colesterol/metabolismo , Cricetulus , Endocitose , Humanos , Imipramina/farmacologia
13.
Opt Express ; 25(10): 11275-11282, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28788809

RESUMO

We report an electrically-switchable two-dimensional liquid crystal (LC) phase grating device for window display applications. The device consists of the top and bottom substrates with crossed interdigitated electrodes and vertically-aligned LCs sandwiched between the two substrates. The device, switchable between the transparent and translucent states by applying an electric field, can provide high haze by the strong diffraction effect thanks to a large spatial phase difference with little dependence on the azimuth angle. We found that the device has outstanding features, such as a low operating voltage, high transparency, and wide viewing angle characteristics in the transparent state and high haze in the translucent state. Moreover, we achieved submillisecond switching between transparent and translucent states by employing the overdrive scheme and a vertical trigger pulse.

14.
Reprod Fertil Dev ; 29(7): 1306-1318, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27279419

RESUMO

Despite evidence of the presence of prostaglandin (PG) I2 in mammalian oviducts, its role in early development of in vitro-produced (IVP) embryos is largely unknown. Thus, in the present study we examined the effects of iloprost, a PGI2 analogue, on the in vitro developmental competence of early porcine embryos and the underlying mechanism(s). To examine the effects of iloprost on the development rate of IVF embryos, iloprost was added to the in vitro culture (IVC) medium and cultured for 6 days. Supplementation of the IVC medium with iloprost significantly improved developmental parameters, such as blastocyst formation rate, the trophectoderm:inner cell mass ratio and cell survival in IVF and parthenogenetically activated (PA) embryos. In addition, post-blastulation development into the expanded blastocyst stage was improved in iloprost-treated groups compared with controls. Interestingly, the phosphatidylinositol 3-kinase (PI3K)/AKT signalling pathway was significantly activated by iloprost supplementation in a concentration-dependent manner (10-1000nM), and the beneficial effects of iloprost on the early development of porcine IVF and PA embryos was completely ablated by treatment with 2.5µM wortmannin, a PI3K/AKT signalling inhibitor. Importantly, expression of the PI3K/AKT signalling pathway was significantly reduced in somatic cell nuclear transfer (SCNT) compared with IVF embryos, and iloprost supported the early development of SCNT embryos, as was the case for IVF and PA embryos, suggesting a consistent effect of iloprost on the IVC of IVP porcine embryos. Together, these results indicate that iloprost can be a useful IVC supplement for production of IVP early porcine embryos with high developmental competence.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Iloprosta/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sus scrofa/embriologia , Sus scrofa/metabolismo , Androstadienos/farmacologia , Animais , Meios de Cultura , Técnicas de Cultura Embrionária/métodos , Técnicas de Cultura Embrionária/veterinária , Desenvolvimento Embrionário/fisiologia , Epoprostenol/análogos & derivados , Epoprostenol/farmacologia , Feminino , Fertilização in vitro/métodos , Fertilização in vitro/veterinária , Modelos Biológicos , Técnicas de Transferência Nuclear/veterinária , Partenogênese , Transdução de Sinais/efeitos dos fármacos , Wortmanina
15.
EMBO J ; 31(17): 3564-74, 2012 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-22863776

RESUMO

The Rpd3S histone deacetylase complex represses cryptic transcription initiation within coding regions by maintaining the hypo-acetylated state of transcribed chromatin. Rpd3S recognizes methylation of histone H3 at lysine 36 (H3K36me), which is required for its deacetylation activity. Rpd3S is able to function over a wide range of H3K36me levels, making this a unique system to examine how chromatin regulators tolerate the reduction of their recognition signal. Here, we demonstrated that Rpd3S makes histone modification-independent contacts with nucleosomes, and that Rpd3S prefers di-nucleosome templates since two binding surfaces can be readily accessed simultaneously. Importantly, this multivalent mode of interaction across two linked nucleosomes allows Rpd3S to tolerate a two-fold intramolecular reduction of H3K36me. Our data suggest that chromatin regulators utilize an intrinsic di-nucleosome-recognition mechanism to prevent compromised function when their primary recognition modifications are diluted.


Assuntos
Histona Desacetilases/metabolismo , Histonas/metabolismo , Nucleossomos/metabolismo , Animais , Metilação , Xenopus
16.
J Thromb Thrombolysis ; 42(1): 107-17, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26680778

RESUMO

High residual platelet activation (HRPA) after ADP stimuli has associated with recurrent vascular events in acute atherothrombosis with the use of antiplatelet agents (APAs). However, there has been little evidence supporting this association in acute ischemic stroke (AIS). In this study, we evaluated the influences of HRPR after ADP stimuli on the 1-year incidence of recurrent cardiovascular events and mortality in AIS with APAs. We conducted an observational, referral center cohort study on 968 AIS patients with APAs from January 2010 to December 2013 who were evaluated using optical platelet aggregometry (OPA). All patients received the dual APA combination of aspirin and clopidogrel or aspirin alone. We evaluated their platelet function 5 days after hospital admission using OPA. HRPR after ADP stimuli was defined as platelet aggregation of 70 % or greater according to OPA after 10 µM ADP stimuli. The primary endpoint was a composite of all causes of death, myocardial infarction, and stroke at the 1-year follow-up. The secondary endpoints were each component of the primary endpoint. The event rate of primary endpoint was 11.3 % (109/968). Its rate was significantly higher in the patients with HRPR (16.7 %) than in those without (9.7 %). HPRP was independently associated with the primary endpoint (OR = 1.97, CI 1.22-3.18, p < 0.01). According to the AIS subtype, the presence of HRPR was independently significant for the occurrence of the primary endpoint in the large artery atherosclerosis (LAA) subtype only (OR = 2.26, CI 1.15-4.45, p = 0.02). In this study, the presence of HRPR after ADP stimuli is associated with a poor long-term outcome after acute ischemic stroke. In particular, the influence of this factor might be more prominent in LAA compared with other types of AIS.


Assuntos
Difosfato de Adenosina/farmacologia , Isquemia Encefálica/sangue , Ativação Plaquetária/efeitos dos fármacos , Acidente Vascular Cerebral/sangue , Aterosclerose/patologia , Estudos de Coortes , Determinação de Ponto Final , Seguimentos , Humanos , Infarto , Inibidores da Agregação Plaquetária/uso terapêutico , Prognóstico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento
17.
J Stroke Cerebrovasc Dis ; 25(7): 1665-1670, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27067887

RESUMO

BACKGROUND: The use of emergency medical services (EMS) and notification to hospitals by paramedics for patients with suspected stroke are crucial determinants in reducing delay time to acute stroke treatment. The aim of this study is to investigate whether EMS use and prehospital notification (PN) can shorten the time to thrombolytic therapy in a stroke center with a systemized stroke code program. METHODS: Beginning in January 2012, stroke experts in our stroke center received direct calls via mobile phone from paramedics prenotifying the transport of patients with suspected stroke. We compared baseline characteristics and prehospital/in-hospital delay time in stroke patients treated with intravenous recombinant tissue plasminogen activator for 44 months with and without EMS use and/or PN. RESULTS: Intravenous thrombolytic therapy was performed on 274 patients. Of those patients, 215 (78.5%) were transported to the hospital via EMS and 59 (21.5%) were admitted via private modes of transportation. The patients who used EMS had shorter median onset-to-arrival times (62 minutes versus 116 minutes, P < .001). There was no difference in in-hospital delay time between the 2 groups. In 28 cases (13%) of EMS transport, EMS personnel called the clinical staff to notify the incoming patient. Prenotification by EMS was associated with shorter median door-to-imaging time (9 minutes versus 12 minutes, P = .045) and door-to-needle time (20 minutes versus 29 minutes, P = .011). CONCLUSIONS: We found that EMS use reduces prehospital delay time. However, EMS use without prenotification does not shorten in-hospital processing time in a stroke center with a systemized stroke code program.


Assuntos
Prestação Integrada de Cuidados de Saúde , Serviços Médicos de Emergência , Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/administração & dosagem , Idoso , Ambulâncias , Telefone Celular , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Avaliação de Programas e Projetos de Saúde , Proteínas Recombinantes/administração & dosagem , República da Coreia , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
18.
EMBO J ; 30(16): 3309-21, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21743438

RESUMO

Centromeres nucleate the formation of kinetochores and are vital for chromosome segregation during mitosis. The SNF2 family helicase PICH (Plk1-interacting checkpoint helicase) and the BLM (the Bloom's syndrome protein) helicase decorate ultrafine histone-negative DNA threads that link the segregating sister centromeres during anaphase. The functions of PICH and BLM at these threads are not understood, however. Here, we show that PICH binds to BLM and enables BLM localization to anaphase centromeric threads. PICH- or BLM-RNAi cells fail to resolve these threads in anaphase. The fragmented threads form centromeric-chromatin-containing micronuclei in daughter cells. Anaphase threads in PICH- and BLM-RNAi cells contain histones and centromere markers. Recombinant purified PICH has nucleosome remodelling activities in vitro. We propose that PICH and BLM unravel centromeric chromatin and keep anaphase DNA threads mostly free of nucleosomes, thus allowing these threads to span long distances between rapidly segregating centromeres without breakage and providing a spatiotemporal window for their resolution.


Assuntos
Centrômero/metabolismo , DNA Helicases/fisiologia , DNA/metabolismo , Nucleossomos/metabolismo , RecQ Helicases/fisiologia , Anáfase , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Células HeLa , Histonas/metabolismo , Humanos , Micronúcleos com Defeito Cromossômico , Ligação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/fisiologia
19.
J Stroke Cerebrovasc Dis ; 24(2): 465-72, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25524016

RESUMO

BACKGROUND: A stroke code can shorten time intervals until intravenous tissue plasminogen activator (IV t-PA) treatment in acute ischemic stroke (AIS). Recently, several reports demonstrated that magnetic resonance imaging (MRI)-based thrombolysis had reduced complications and improved outcomes in AIS despite longer processing compared with computed tomography (CT)-based thrombolysis. METHODS: In January 2009, we implemented CODE RED, a computerized stroke code, at our hospital with the aim of achieving rapid stroke assessment and treatment. We included patients with thrombolysis from January 2007 to December 2008 (prestroke code period) and from January 2009 to May 2013 (poststroke code period). The IV t-PA time intervals and 90-day modified Rankin Scale (mRS) scores were collected. RESULTS: During the observation period, 252 patients used IV t-PA under the CODE RED (MRI based: 208; CT based: 44). The remaining 71 patients (MRI based: 53; CT based: 18) received it before the implementation of our stroke code. After implementation of CODE RED, door-to-image time, door-to-needle time, and the onset-to-needle time were significantly reduced by 11, 18, and 22 minutes in MRI-based thrombolysis. Particularly, the proportion of favorable outcome (mRS score 0-2) was significantly increased (from 41.5% to 60.1%, P = .02) in poststroke than in prestroke code period in MRI-based thrombolysis. However, in ordinal regression, the presence of stroke code showed just a trend for favorable outcome (odds ratio, .99-2.87; P = .059) at 90 days of using IV t-PA after correction of age, sex, and National Institutes of Health Stroke Scale. CONCLUSIONS: In this study, we demonstrated that a systemized stroke code shortened time intervals for using IV t-PA under MRI screening. Also, our results showed a possibility that a systemized stroke code might enhance the efficacy of MRI-based thrombolysis. In the future, we need to carry out a more detailed prospective study about this notion.


Assuntos
Encéfalo/patologia , Fibrinolíticos/uso terapêutico , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/diagnóstico , Ativador de Plasminogênio Tecidual/uso terapêutico , Administração Intravenosa , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Fatores de Tempo
20.
Int J Mol Sci ; 16(2): 2386-402, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25622254

RESUMO

The accumulation and aggregation of misfolded proteins in the brain, such as amyloid-ß (Aß) and hyperphosphorylated tau, is a neuropathological hallmark of Alzheimer's disease (AD). Previously, we developed and validated a novel non-human primate model for sporadic AD (sAD) research using intracerebroventricular administration of streptozotocin (icv STZ). To date, no characterization of AD-related genes in different brain regions has been performed. Therefore, in the current study, the expression of seven amyloid precursor protein (APP) pathway-related and five tau phosphorylation-related genes was investigated by quantitative real-time PCR experiments, using two matched-pair brain samples from control and icv STZ-treated cynomolgus monkeys. The genes showed similar expression patterns within the control and icv STZ-treated groups; however, marked differences in gene expression patterns were observed between the control and icv STZ-treated groups. Remarkably, other than ß-secretase (BACE1) and cyclin-dependent kinase 5 (CDK5), all the genes tested showed similar expression patterns in AD models compared to controls, with increased levels in the precuneus and occipital cortex. However, significant changes in gene expression patterns were not detected in the frontal cortex, hippocampus, or posterior cingulate. Based on these results, we conclude that APP may be cleaved via the general metabolic mechanisms of increased α- and γ-secretase levels, and that hyperphosphorylation of tau could be mediated by elevated levels of tau protein kinase, specifically in the precuneus and occipital cortex.


Assuntos
Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Calpaína/genética , Calpaína/metabolismo , Quinase 5 Dependente de Ciclina/genética , Quinase 5 Dependente de Ciclina/metabolismo , Modelos Animais de Doenças , Feminino , Quinase 3 da Glicogênio Sintase/genética , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Macaca fascicularis , Fosforilação , RNA Mensageiro/metabolismo , Estreptozocina/toxicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA