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1.
Allergol Int ; 71(3): 362-372, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35272957

RESUMO

BACKGROUND: Tingling dermal pain triggered by sweating impairs the lives of patients with cholinergic urticaria and generalized anhidrosis. However, dermal pain evoked by sweating stimuli has been under investigated. METHODS: To clarify characteristics of tingling dermal pain on sweating, we retrospectively evaluated clinical and histopathological manifestations in 30 patients having the main problem of dermal pain on sweating, and the efficacy of treatments. RESULTS: Dermal pain upon sweating affected mostly young males. It accompanied eruptions upon sweating and/or hypohidrosis in 24 patients, while 6 patients had dermal pain independently of hypohidrosis or eruptions. Dermal pain appeared immediately upon exposure to sweating stimuli, and disappeared within mostly 30 or 10 min. Hypohidrosis was not necessarily generalized but localized or absent. Histological analysis revealed that dermal pain could occur even without morphological changes and inflammation of sweat glands. Hypersensitivity to sweat contents was found only in 26% of patients. Sweat histamine and increase of plasma histamine after thermal induction in patients were significantly higher than those in healthy subjects. Effectiveness of steroid pulse therapy was demonstrated for dermal pain with hypohidrosis. Medications acting on nervous systems and regular sweat-inducing activities for promoting perspiration were also effective. CONCLUSIONS: Short-lasting tingling dermal pain appears immediately upon exposure to sweating stimuli, regardless of developing eruptions and/or presence of hypohidrosis, but possibly in association with sweat and plasma histamine.


Assuntos
Hipo-Hidrose , Urticária , Histamina , Humanos , Hipo-Hidrose/complicações , Hipo-Hidrose/tratamento farmacológico , Hipo-Hidrose/patologia , Masculino , Dor/complicações , Estudos Retrospectivos , Sudorese , Urticária/patologia
2.
Cereb Cortex ; 29(3): 1121-1138, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29415216

RESUMO

How the variety of neurons that organize into neocortical layers and functional areas arises is a central question in the study of cortical development. While both intrinsic and extrinsic cues are known to influence this process, whether distinct neuronal progenitor groups contribute to neuron diversity and allocation is poorly understood. Using in vivo genetic fate-mapping combined with whole-cell patch clamp recording, we show that the firing pattern and apical dendritic morphology of excitatory neurons in layer 4 of the barrel cortex are specified in part by their neural precursor lineage. Further, we show that separate precursors contribute to unique features of barrel cortex topography including the intralaminar position and thalamic innervation of the neurons they generate. Importantly, many of these lineage-specified characteristics are different from those previously measured for pyramidal neurons in layers 2-3 of the frontal cortex. Collectively, our data elucidate a dynamic temporal program in neuronal precursors that fine-tunes the properties of their progeny according to the lamina of destination.


Assuntos
Células-Tronco Neurais/fisiologia , Células Piramidais/fisiologia , Córtex Somatossensorial/crescimento & desenvolvimento , Potenciais de Ação , Animais , Espinhas Dendríticas , Feminino , Masculino , Camundongos , Modelos Neurológicos , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Células Piramidais/citologia , Córtex Somatossensorial/citologia , Proteínas com Domínio T/metabolismo
3.
FASEB J ; 30(12): 4149-4158, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27601443

RESUMO

Fatty acids are taken up by cells and incorporated into complex lipids such as neutral lipids and glycerophospholipids. Glycerophospholipids are major constituents of cellular membranes. More than 1000 molecular species of glycerophospholipids differ in their polar head groups and fatty acid compositions. They are related to cellular functions and diseases and have been well analyzed by mass spectrometry. However, intracellular imaging of fatty acids and glycerophospholipids has not been successful due to insufficient resolution using conventional methods. Here, we developed a method for labeling fatty acids with bromine (Br) and applied scanning X-ray fluorescence microscopy (SXFM) to obtain intracellular Br mapping data with submicrometer resolution. Mass spectrometry showed that cells took up Br-labeled fatty acids and metabolized them mainly into glycerophospholipids in CHO cells. Most Br signals observed by SXFM were in the perinuclear region. Higher resolution revealed a spot-like distribution of Br in the cytoplasm. The current method enabled successful visualization of intracellular Br-labeled fatty acids. Single-element labeling combined with SXFM technology facilitates the intracellular imaging of fatty acids, which provides a new tool to determine dynamic changes in fatty acids and their derivatives at the single-cell level.-Shimura, M., Shindou, H., Szyrwiel, L., Tokuoka, S. M., Hamano, F., Matsuyama, S., Okamoto, M., Matsunaga, A., Kita, Y., Ishizaka, Y., Yamauchi, K., Kohmura, Y., Lobinski, R., Shimizu, I., Shimizu, T. Imaging of intracellular fatty acids by scanning X-ray fluorescence microscopy.


Assuntos
Membrana Celular/metabolismo , Ácidos Graxos/metabolismo , Glicerofosfolipídeos/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Citoplasma/metabolismo , Metabolismo dos Lipídeos , Lipídeos , Microscopia de Fluorescência/métodos , Raios X
4.
PLoS Genet ; 10(9): e1004639, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25233213

RESUMO

Nonessential tRNA modifications by methyltransferases are evolutionarily conserved and have been reported to stabilize mature tRNA molecules and prevent rapid tRNA decay (RTD). The tRNA modifying enzymes, NSUN2 and METTL1, are mammalian orthologs of yeast Trm4 and Trm8, which are required for protecting tRNA against RTD. A simultaneous overexpression of NSUN2 and METTL1 is widely observed among human cancers suggesting that targeting of both proteins provides a novel powerful strategy for cancer chemotherapy. Here, we show that combined knockdown of NSUN2 and METTL1 in HeLa cells drastically potentiate sensitivity of cells to 5-fluorouracil (5-FU) whereas heat stress of cells revealed no effects. Since NSUN2 and METTL1 are phosphorylated by Aurora-B and Akt, respectively, and their tRNA modifying activities are suppressed by phosphorylation, overexpression of constitutively dephosphorylated forms of both methyltransferases is able to suppress 5-FU sensitivity. Thus, NSUN2 and METTL1 are implicated in 5-FU sensitivity in HeLa cells. Interfering with methylation of tRNAs might provide a promising rationale to improve 5-FU chemotherapy of cancer.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Fluoruracila/farmacologia , Metiltransferases/metabolismo , RNA de Transferência/metabolismo , Proliferação de Células , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica , Técnicas de Silenciamento de Genes , Células HeLa , Resposta ao Choque Térmico/genética , Humanos , Metiltransferases/genética , Paclitaxel/farmacologia , Fosforilação , Estabilidade de RNA/efeitos dos fármacos , RNA de Transferência/genética , Ensaio Tumoral de Célula-Tronco
5.
J Cell Physiol ; 231(11): 2493-505, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26919575

RESUMO

The equilibrium between proliferation and apoptosis is tightly balanced to maintain tissue homeostasis in normal tissues and even in tumors. Achieving and maintaining such a balance is important for cancer regrowth and spreading after cytotoxic treatments. Caspase-3 activation and tumor cell death following anticancer therapy as well as accompanying cell death pathways are well characterized, but their association to homeostasis of cancerous tissue and tumor progression remains poorly understood. Here we proposed a novel mechanism of cancer spreading induced by caspase-3. RhoGDIß, known as a direct cleavage substrate of caspase-3, is overexpressed in many epithelial cancers. The N-terminal-truncated RhoGDIß (ΔN-RhoGDIß) is accumulated in caspase-3-activated cells. Stable expression of ΔN-RhoGDIß in HeLa cells did not induce apoptosis, but impaired directional cell migration in a wound-healing assay accompanied by a perturbed direction of cell division at the wound edge. Subcellular protein fractionation experiments revealed that ΔN-RhoGDIß but not wild-type RhoGDIß was present in the detergent-soluble cytoplasmic and nuclear fractions and preferentially associated with Cdc42. Furthermore, Cdc42 activity was constitutively inhibited by stable expression of ΔN-RhoGDIß, resulting in increased radiation-induced compensatory proliferation linking to RhoA activation. Thus, ΔN-RhoGDIß dominant-negatively regulates Cdc42 activity and contributes to loss of polarity-related functions. The caspase-3-cleaved RhoGDIß is a possible determinant to promote cancer spreading due to deregulation of directional organization of tumor cell population and inhibition of default equilibrium between proliferation and apoptosis after cytotoxic damage. J. Cell. Physiol. 231: 2493-2505, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Movimento Celular/efeitos da radiação , Polaridade Celular/efeitos da radiação , Neoplasias/patologia , Radiação , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/metabolismo , Apoptose/efeitos da radiação , Caspase 3/metabolismo , Divisão Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Regulação para Baixo/efeitos da radiação , Ativação Enzimática/efeitos da radiação , Genes Dominantes , Células HeLa , Humanos , Modelos Biológicos , Proteínas Mutantes/metabolismo , Metástase Neoplásica , Transporte Proteico/efeitos da radiação , Frações Subcelulares/metabolismo , Raios X , Proteína cdc42 de Ligação ao GTP/metabolismo
6.
Biol Pharm Bull ; 39(8): 1387-91, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27476947

RESUMO

Two vitamin D3 derivatives, namely 24,24-difluoro-1ß,3ß,25-dihydroxy-19-norvitamin D3 (6a) and 24,24-difluoro-1α,3α,25-dihydroxy-19-norvitamin D3 (6b), were synthesized via a convergent route employing Julia-Kocienski olefination as a key step. Compounds 6a and b bound to vitamin D receptor (VDR) with IC50 values of 64.8 and 57.6 nM, respectively, exhibiting about 400- and 30-fold greater binding affinity than the corresponding non-fluorinated derivatives 5a and b.


Assuntos
Colecalciferol/análogos & derivados , Colecalciferol/metabolismo , Receptores de Calcitriol/metabolismo
8.
Dev Growth Differ ; 56(4): 293-304, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24712911

RESUMO

To achieve highly sensitive and comprehensive assessment of the morphology and dynamics of cells committed to the neuronal lineage in mammalian brain primordia, we generated two transgenic mouse lines expressing a destabilized (d4) Venus controlled by regulatory elements of the Neurogenin2 (Neurog2) or Gadd45g gene. In mid-embryonic neocortical walls, expression of Neurog2-d4Venus mostly overlapped with that of Neurog2 protein, with a slightly (1 h) delayed onset. Although Neurog2-d4Venus and Gadd45g-d4Venus mice exhibited very similar labeling patterns in the ventricular zone (VZ), in Gadd45g-d4Venus mice cells could be visualized in more basal areas containing fully differentiated neurons, where Neurog2-d4Venus fluorescence was absent. Time-lapse monitoring revealed that most d4Venus(+) cells in the VZ had processes extending to the apical surface; many of these cells eventually retracted their apical process and migrated basally to the subventricular zone, where neurons, as well as the intermediate neurogenic progenitors that undergo terminal neuron-producing division, could be live-monitored by d4Venus fluorescence. Some d4Venus(+) VZ cells instead underwent nuclear migration to the apical surface, where they divided to generate two d4Venus(+) daughter cells, suggesting that the symmetric terminal division that gives rise to neuron pairs at the apical surface can be reliably live-monitored. Similar lineage-committed cells were observed in other developing neural regions including retina, spinal cord, and cerebellum, as well as in regions of the peripheral nervous system such as dorsal root ganglia. These mouse lines will be useful for elucidating the cellular and molecular mechanisms underlying development of the mammalian nervous system.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Encéfalo/citologia , Encéfalo/embriologia , Proteínas de Transporte/metabolismo , Linhagem da Célula , Movimento Celular , Mitose , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Transporte/genética , Diferenciação Celular , Células Cultivadas , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Transgênicos , Mitose/genética , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Imagem com Lapso de Tempo
9.
J Plant Res ; 126(1): 73-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22653327

RESUMO

Macaranga myrmecophytes (ant-plants) provide their partner symbiotic ants (plant-ants) with food bodies as their main food, and they are protected by the plant-ants from herbivores. The amount of resource allocated to food bodies determines the plant-ant colony size and consequently determines the intensity of ant defense (anti-herbivore defense by plant-ants). As constraints in resource allocation change as plants grow, the plant-ant colony size is hypothesized to change with the ontogenesis of Macaranga myrmecophyte. To determine the ontogenetic change in the relative size of the plant-ant colony, we measured the dry weights of the whole plant-ant colony and all of the aboveground parts of trees at various ontogenetic stages for a myrmecophytic species (Macaranga beccariana) in a Bornean lowland tropical rain forest. Ant biomass increased as plant biomass increased. However, the rate of increase gradually declined, and the ant biomass appeared to reach a ceiling once trees began to branch. The ant/plant biomass ratio consistently decreased as plant biomass increased, with the rate of decrease gradually accelerating. We infer that the ontogenetic reduction in ant/plant biomass ratio is caused by an ontogenetic change in resource allocation to food rewards for ants related to the physiological changes accompanying the beginning of branching.


Assuntos
Formigas/fisiologia , Biomassa , Euphorbiaceae/fisiologia , Simbiose/fisiologia , Animais , Bornéu , Ecossistema , Especificidade da Espécie , Árvores , Clima Tropical
10.
Mutat Res ; 688(1-2): 78-87, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20346366

RESUMO

In mouse thymic lymphoma 3SB cells bearing wild type p53, ionizing radiation (IR) and UV light are potent triggers of caspase-3-dependent apoptosis. Although cytochrome c was released from mitochondria as expected, caspase-9 activation was not observed in UV-exposed cells. Laser scanning confocal microscopy analysis showed that caspase-9 is localized in an unusual punctuated pattern in UV-induced apoptotic cells. In agreement with differences in the status of caspase-9 activation between IR and UV, subcellular protein fractionation experiments showed that pro-apoptotic apoptosis protease-activating factor 1 (Apaf-1), normally a part of the apoptosome assembled in response to the release of cytochrome c from mitochondria, and B-cell lymphoma extra long (Bcl-xL), an inhibitor of the change in mitochondrial membrane permeability, were redistributed by the IR-exposure but not by the UV-exposure. Instead of the sequestration of the capase-9/apoptosome activation in UV-induced apoptotic cells, the extrinsic apoptotic signaling generated by caspase-8 activation and consequent activation of B-cell lymphoma extra long (Bid) to release cytochrome c from mitochondria was observed. Thus, the post-mitochondrial apoptotic pathway downstream of cytochrome c release cannot operate the apoptosome function in UV-induced apoptosis in thymic 3SB cells. The intracellular redistribution and sequestration of apoptosis-related proteins upon mitochondrion-based apoptotic signaling was identified as a novel cellular mechanism to respond to DNA damage in an agent type-specific manner. This finding suggests that the kind of the critical ultimate apoptosis-inducing DNA lesion complex form resulting from the agent-specific DNA damage responses is important to determine which of apoptosis signals would be activated.


Assuntos
Caspase 9/metabolismo , Radiação Ionizante , Timo/efeitos da radiação , Raios Ultravioleta , Animais , Apoptose/efeitos da radiação , Caspase 3/metabolismo , Fracionamento Celular , Células Cultivadas , Citocromos c/metabolismo , Ativação Enzimática/efeitos da radiação , Camundongos , Mitocôndrias/metabolismo , Timo/metabolismo
11.
Biosci Biotechnol Biochem ; 74(2): 292-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20139619

RESUMO

C-Reactive protein (CRP) is an acute-phase protein that increases during systemic inflammation and is currently one of the most frequently studied inflammatory markers in epidemiology. We have determined CRP concentration using novel latex reagent with polyclonal antibody. In the present study, we determined the concentration of CRP using monoclonal antibodies, and evaluated the interaction of antigen-antibody reactive sites and latex agglutination to detect low CRP concentrations. We developed four novel monoclonal antibodies that we classified into two major groups, and that were used to prepare the latex reagents. The latex reagents prepared using a cocktail of monoclonal antibodies for different epitopes appeared highly sensitive. The lower limit of CRP detection, which was defined using the mean 3 SD method, was calculated to be 5 ng/ml for the latex reagents when oligoclonal antibodies were utilized. Furthermore, the latex reagents were found to react specifically with CRP in clinical samples.


Assuntos
Anticorpos Monoclonais/imunologia , Proteína C-Reativa/imunologia , Epitopos/análise , Indicadores e Reagentes/análise , Látex/análise , Humanos , Testes de Fixação do Látex/métodos
12.
Sci Adv ; 6(45)2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33158872

RESUMO

How the rich variety of neurons in the nervous system arises from neural stem cells is not well understood. Using single-cell RNA-sequencing and in vivo confirmation, we uncover previously unrecognized neural stem and progenitor cell diversity within the fetal mouse and human neocortex, including multiple types of radial glia and intermediate progenitors. We also observed that transcriptional priming underlies the diversification of a subset of ventricular radial glial cells in both species; genetic fate mapping confirms that the primed radial glial cells generate specific types of basal progenitors and neurons. The different precursor lineages therefore diversify streams of cell production in the developing murine and human neocortex. These data show that transcriptional priming is likely a conserved mechanism of mammalian neural precursor lineage specialization.


Assuntos
Neocórtex , Células-Tronco Neurais , Animais , Diferenciação Celular/genética , Células Ependimogliais , Humanos , Mamíferos , Camundongos , Células-Tronco Neurais/fisiologia , Neurogênese/genética , Neurônios/fisiologia
13.
Gene Expr Patterns ; 9(5): 306-13, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19272464

RESUMO

The mechanisms underlying retinal cell diversification are crucial to proper neural development. Fibroblast growth factor 19 (Fgf19) is expressed by developing horizontal cells (HCs) in the chicken retina. Although there are two major HC subtypes, axon-bearing and axon-less, the precise subtype expressing Fgf19 remains uncertain. Here we characterize Fgf19-expressing cells by co-labeling with antibodies against Lim1 (LIM homeodomain 1, or Lhx1), Islet1, and Prox1 (prospero-related homeobox 1) which are axon-bearing HC, axon-less HC, and pan-HC markers, respectively. We found that a subset of Fgf19-expressing cells was positive for Prox1 and Lim1 in the vitread neuroepithelium at embryonic day 4 (E4). By E9, the majority of Fgf19-expressing cells became positive for Prox1 and Lim1 prior to arrival at the prospective HC layer. In contrast, Fgf19-expressing cells did not overlap with the Islet1-positive population at any stage examined. These results suggest that Fgf19 is expressed by the early migratory horizontal precursors, and later by the presumptive axon-bearing HCs.


Assuntos
Fatores de Crescimento de Fibroblastos/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Retina/metabolismo , Células Horizontais da Retina/metabolismo , Animais , Movimento Celular , Embrião de Galinha , Galinhas , Fatores de Crescimento de Fibroblastos/metabolismo , Imunofluorescência , Proteínas de Homeodomínio/metabolismo , Hibridização In Situ , Retina/citologia , Retina/embriologia , Fatores de Tempo , Proteínas Supressoras de Tumor/metabolismo
14.
Oncol Rep ; 22(3): 557-62, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19639203

RESUMO

Survivin is a bifunctional protein that suppresses apoptosis and regulates cell division and is highly expressed in various human cancers. Recently, the intracellular localization of survivin in tumors has been suggested as a prognostic marker, but the molecular mechanisms are not understood. The aims of the present study were to investigate the different localization of survivin expression in colorectal carcinoma and expression of survivin relationships with clinicopathological factors and patient survival. Immunohistochemical analyses of 142 cases of advanced colorectal cancer showed that 109 (76.8%) cases expressed survivin in the nucleus and 29 cases (20.4%) in the cytoplasm. Cytoplasmic survivin overexpression was associated with a poor prognosis, but nuclear survivin overexpression was associated with a better prognosis. Subcellular distribution of survivin in five cases of cancerous or surrounding normal tissues derived from fresh biopsy of non-fixed samples of colorectal cancer patients was further demonstrated by Western blotting. Survivin was primarily found in the insoluble fraction. Interestingly, regardless of survivin protein levels in the insoluble fraction, patients who had cancerous tissue expressing cytoplasmic and nuclear soluble survivin suffered from lymph nodes metastases. These data suggest that the function of cytoplasmic survivin might be important for malignant progress and the levels of cytoplasmic and nuclear soluble survivin might be more relevant for prognostic factors for colorectal cancer than the total amount of survivin.


Assuntos
Neoplasias Colorretais/química , Proteínas Associadas aos Microtúbulos/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Núcleo Celular/química , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Citoplasma/química , Feminino , Humanos , Imuno-Histoquímica , Proteínas Inibidoras de Apoptose , Masculino , Proteínas Associadas aos Microtúbulos/fisiologia , Pessoa de Meia-Idade , Metástase Neoplásica , Survivina
15.
Cell Rep ; 29(6): 1555-1567.e5, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31693895

RESUMO

Despite recent studies elucidating the molecular mechanisms underlying cortical patterning and map formation, very little is known about how the embryonic pallium expands ventrally to form the future cortex and the nature of the underlying force-generating events. We find that neurons born at embryonic day 10 (E10) in the mouse dorsal pallium ventrally stream until E13, thereby superficially spreading the preplate, and then constitute the subplate from E14. From E11 to E12, the preplate neurons migrate, exerting pulling and pushing forces at the process and the soma, respectively. At E13, they are morphologically heterogeneous, with ∼40% possessing corticofugal axons, which are found to be in tension. Ablation of these E10-born neurons attenuates both deflection of radial glial fibers (by E13) and extension of the cortical plate (by E14), which should occur ventrally, and subsequently shrinks the postnatal neocortical map dorsally. Thus, the preplate stream physically primes neocortical expansion and arealization.


Assuntos
Axônios/fisiologia , Córtex Cerebral/embriologia , Células Ependimogliais/citologia , Neocórtex/embriologia , Neurônios/fisiologia , Animais , Axônios/metabolismo , Movimento Celular , Córtex Cerebral/citologia , Córtex Cerebral/fisiologia , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário , Células Ependimogliais/metabolismo , Células Ependimogliais/fisiologia , Camundongos , Camundongos Knockout , Neocórtex/citologia , Neocórtex/metabolismo , Neocórtex/fisiologia , Neurônios/citologia , Córtex Somatossensorial/citologia , Córtex Somatossensorial/embriologia , Córtex Somatossensorial/metabolismo
16.
Dev Growth Differ ; 50(3): 159-68, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18312426

RESUMO

Fgf19 is known to be expressed in the developing chicken eye but its functions during retinal development have remained elusive. Since Fgf19 is expressed in the dorsal portion of the optic cup, it is intriguing to know whether FGF19 is required for expression of dorso-ventral morphogenetic genes in the eye. To clarify this, expression patterns of Tbx5 and Vax were examined in the developing eye after in ovo RNA interference targeted against Fgf19. Quantitative polymerase chain reaction (PCR) analysis showed that the short-hairpin RNAs (shRNAs) targeted against Fgf19 could reduce its expression in the eye to less than 50% of a relative amount of mRNA, compared with contralateral or untreated control eyes. However, no obvious alteration in expression domains of Tbx5 or Vax was observed. Misexpression of Tbx5 or Tbx5-RNAi did not alter the Fgf19 expression either. Furthermore, although Fgf19 is expressed in the central retina before neurogenesis occurs, beta3-tubulin, a marker for early retinal differentiation was still detected in the central retina after knockdown of Fgf19. Thus, knockdown of Fgf19 supports no obvious regulations between Fgf19 and Tbx5, or exhibits no phenotypes that perturb early retinal differentiation.


Assuntos
Proteínas do Olho/biossíntese , Fatores de Crescimento de Fibroblastos/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Interferência de RNA , Retina/embriologia , Proteínas com Domínio T/biossíntese , Tubulina (Proteína)/biossíntese , Animais , Células Cultivadas , Embrião de Galinha , Eletroporação , Proteínas do Olho/genética , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Fatores de Crescimento de Fibroblastos/biossíntese , Fatores de Crescimento de Fibroblastos/genética , Morfogênese/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , RNA Interferente Pequeno/genética , Retina/metabolismo , Proteínas com Domínio T/genética , Transgenes , Tubulina (Proteína)/genética
17.
Science ; 360(6386): 313-317, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29674592

RESUMO

The neocortex exhibits a six-layered structure that is formed by radial migration of excitatory neurons, for which the multipolar-to-bipolar transition of immature migrating multipolar neurons is required. Here, we report that subplate neurons, one of the first neuron types born in the neocortex, manage the multipolar-to-bipolar transition of migrating neurons. By histochemical, imaging, and microarray analyses on the mouse embryonic cortex, we found that subplate neurons extend neurites toward the ventricular side of the subplate and form transient glutamatergic synapses on the multipolar neurons just below the subplate. NMDAR (N-methyl-d-aspartate receptor)-mediated synaptic transmission from subplate neurons to multipolar neurons induces the multipolar-to-bipolar transition, leading to a change in migration mode from slow multipolar migration to faster radial glial-guided locomotion. Our data suggested that transient synapses formed on early immature neurons regulate radial migration.


Assuntos
Movimento Celular , Neocórtex/citologia , Neocórtex/embriologia , Neurogênese , Neurônios/fisiologia , Transmissão Sináptica , Animais , Comunicação Celular , Técnicas de Introdução de Genes , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Toxina Tetânica/genética
19.
Ann Nucl Med ; 31(1): 53-62, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27680022

RESUMO

OBJECTIVE: 7α-Substituted androgen derivatives may have the potential to visualize androgen receptors with positron emission tomography. In the present study, we synthesized fluoropropyl derivatives of 7α-(3-[18F]fluoropropyl)-testosterone ([18F]7) and 7α-(3-[18F]fluoropropyl)-dihydrotestosterone ([18F]15), and characterized their in vitro binding, in vivo biodistribution, and performed blocking studies in mature androgen deprived male rats. METHODS: We synthesized [18F]7 and [18F]15. In vitro binding to recombinant rat AR ligand binding domain protein was determined using a competitive radiometric ligand-binding assay with the high-affinity synthetic androgen [17α-methyl-3H]-methyltrienolone ([3H]R1881). In vivo biodistribution was performed in mature male rats treated with diethylstilbestrol (chemical castration). A blocking study was performed by co-administration of dihydrotestosterone (36 µg/animal). RESULTS: 7α-(3-Fluoropropyl)-testosterone (7) and 7α-(3-fluoropropyl)-dihydrotestosterone (15) showed competitive binding to recombinant rat AR ligand binding domain protein. The IC50 value of 15 (13.0 ± 3.3 nM) was higher than 7 (47.8 ± 10.0 nM). In contrast to the AR binding affinity, the ventral prostate uptake of [18F]7 and [18F]15 at 2 h post-injection was similar (0.07 % injected dose/g of tissue). A blocking study indicated that specific binding of [18F]15 is observed in the ventral prostate. [18F]7 and [18F]15 showed moderate levels of bone uptake, which indicates moderate metabolic de-fluorination in rodents. CONCLUSION: [18F]15 is better than [18F]7 in terms of radiochemical yield, in vitro binding affinity, prostate specific binding and stability against in vivo metabolic de-fluorination. However, the net uptake level of [18F]15 in prostate might be insufficient for in vivo visualization. Although [18F]7 and [18F]15 improved in vivo stability against de-fluorination, other basic characterization data in rodents were not superior to the current standard tracer 16ß-[18F]fluoro-5α-dihydrotestosterone. It is also revealed that the shorter side chain length of 7α-[18F]fluoromethyl-dihydrotestosterone is superior to the longer three carbon chain in [18F]15, in terms of net prostate uptake and in vivo metabolic stability.


Assuntos
Di-Hidrotestosterona/síntese química , Di-Hidrotestosterona/metabolismo , Testosterona/análogos & derivados , Testosterona/síntese química , Testosterona/metabolismo , Androgênios/deficiência , Animais , Técnicas de Química Sintética , Di-Hidrotestosterona/química , Di-Hidrotestosterona/farmacocinética , Masculino , Radioquímica , Ratos , Receptores Androgênicos/metabolismo , Testosterona/química , Testosterona/farmacocinética , Distribuição Tecidual
20.
Mitochondrion ; 6(6): 299-304, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17098481

RESUMO

It is known that mitochondrial DNA (mtDNA) replication is independent of the cell cycle. Even in post-mitotic cells in which nuclear DNA replication has ceased, mtDNA is believed to still be replicating. Here, we investigated the turnover rate of mtDNA in primary rat hepatocytes, which are quiescent cells. Southwestern blot analysis using 5-bromo-2'-deoxyuridine (BrdU) was employed to estimate the activity of full-length mtDNA replication and to determine efficient doses of replication inhibitors. Southern blot analysis showed that a two-day treatment with 20mM 2',3'-dideoxycytidine and 0.2mug/ml ethidium bromide caused a 37% reduction in the amount of mtDNA, indicating that the hepatocytes had a considerably high rate of turnover of mtDNA. Further, pulse-chase analysis using Southwestern analysis showed that the amount of newly synthesized mtDNA labeled with BrdU declined to 60% of the basal level within two days. Because the rate of reduction of the new mtDNA was very similar to the overall turnover rate described above, it appears that degrading mtDNA molecules were randomly chosen. Thus, we demonstrated that there is highly active and random turnover of mtDNA in hepatocytes.


Assuntos
DNA Mitocondrial/metabolismo , Hepatócitos/citologia , Hepatócitos/metabolismo , Mitocôndrias Hepáticas/genética , Mitocôndrias Hepáticas/metabolismo , Animais , Bromouracila/metabolismo , Células Cultivadas , Replicação do DNA , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
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