RESUMO
Numerous evidence corroborates roles of gap junctions/hemichannels in proper kidney development. We analyzed how Dab1 gene functional silencing influences expression and localization of Cx37, Cx40, Cx43, Cx45, Panx1 and renin in postnatal kidneys of yotari mice, by using immunohistochemistry and electron microscopy. Dab1 Δ102/221 might lead to the activation of c-Src tyrosine kinase, causing the upregulation of Cx43 in the medulla of yotari mice. The expression of renin was more prominent in yotari mice (p < 0.001). Renin granules were unusually present inside the vascular walls of glomeruli capillaries, in proximal and distal convoluted tubules and in the medulla. Disfunction of Cx40 is likely responsible for increased atypically positioned renin cells which release renin in an uncontrolled fashion, but this doesn't rule out simultaneous involvement of other Cxs, such as Cx45 which was significantly increased in the yotari cortex. The decreased Cx37 expression in yotari medulla might contribute to hypertension reduction provoked by high renin expression. These findings imply the relevance of Cxs/Panx1 as markers of impaired kidney function (high renin) in yotari mice and that they have a role in the preservation of intercellular signaling and implicate connexopathies as the cause of premature death of yotari mice.
Assuntos
Conexina 43/genética , Conexinas/genética , Glomérulos Renais/metabolismo , Proteínas do Tecido Nervoso/genética , Renina/genética , Animais , Animais Recém-Nascidos , Conexina 43/metabolismo , Conexinas/metabolismo , Junções Comunicantes/metabolismo , Junções Comunicantes/patologia , Regulação da Expressão Gênica no Desenvolvimento , Glomérulos Renais/crescimento & desenvolvimento , Glomérulos Renais/patologia , Medula Renal/crescimento & desenvolvimento , Medula Renal/metabolismo , Medula Renal/patologia , Túbulos Renais/crescimento & desenvolvimento , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/metabolismo , Renina/metabolismo , Transdução de Sinais , Proteína alfa-5 de Junções Comunicantes , Proteína alfa-4 de Junções ComunicantesRESUMO
Polyunsaturated fatty acids (PUFAs) are essential for brain development and function. Increasing evidence has shown that an imbalance of PUFAs is associated with various human psychiatric disorders, including autism and schizophrenia. Fatty acid-binding proteins (FABPs), cellular chaperones of PUFAs, are involved in PUFA intracellular trafficking, signal transduction, and gene transcription. In this study, we show that FABP3 is strongly expressed in the GABAergic inhibitory interneurons of the male mouse anterior cingulate cortex (ACC), which is a component of the limbic cortex and is important for the coordination of cognitive and emotional behaviors. Interestingly, Fabp3 KO male mice show an increase in the expression of the gene encoding the GABA-synthesizing enzyme glutamic acid decarboxylase 67 (Gad67) in the ACC. In the ACC of Fabp3 KO mice, Gad67 promoter methylation and the binding of methyl-CpG binding protein 2 (MeCP2) and histone deacetylase 1 (HDAC1) to the Gad67 promoter are significantly decreased compared with those in WT mice. The abnormal cognitive and emotional behaviors of Fabp3 KO mice are restored by methionine administration. Notably, methionine administration normalizes Gad67 promoter methylation and its mRNA expression in the ACC of Fabp3 KO mice. These findings demonstrate that FABP3 is involved in the control of DNA methylation of the Gad67 promoter and activation of GABAergic neurons in the ACC, thus suggesting the importance of PUFA homeostasis in the ACC for cognitive and emotional behaviors.SIGNIFICANCE STATEMENT The ACC is important for emotional and cognitive processing. However, the mechanisms underlying its involvement in the control of behavioral responses are largely unknown. We show the following new observations: (1) FABP3, a PUFA cellular chaperone, is exclusively expressed in GABAergic interneurons in the ACC; (2) an increase in Gad67 expression is detected in the ACC of Fabp3 KO mice; (3) the Gad67 promoter is hypomethylated and the binding of transcriptional repressor complexes is decreased in the ACC of Fabp3 KO mice; and (4) elevated Gad67 expression and abnormal behaviors seen in Fabp3 KO mice are mostly recovered by methionine treatment. These suggest that FABP3 regulates GABA synthesis through transcriptional regulation of Gad67 in the ACC.
Assuntos
Metilação de DNA/fisiologia , Proteína 3 Ligante de Ácido Graxo/biossíntese , Glutamato Descarboxilase/metabolismo , Giro do Cíngulo/metabolismo , Regiões Promotoras Genéticas/fisiologia , Animais , Linhagem Celular Tumoral , Proteína 3 Ligante de Ácido Graxo/genética , Glutamato Descarboxilase/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Técnicas de Cultura de ÓrgãosRESUMO
Reelin-Dab1 signaling is involved in brain development and neuronal functions. The abnormalities in the signaling through either reduction of Reelin and Dab1 gene expressions or the genomic mutations in the brain have been reported to be associated with psychiatric disorders. However, it has not been clear if the deficiency in Reelin-Dab1 signaling is responsible for symptoms of the disorders. Here, to examine the function of Reelin-Dab1 signaling in the forebrain, we generated dorsal forebrain-specific Dab1 conditional knockout mouse (Dab1 cKO) and performed a behavioral test battery on the Dab1 cKO mice. Although conventional Dab1 null mutant mice exhibit cerebellar atrophy and cerebellar ataxia, the Dab1 cKO mice had normal cerebellum and showed no motor dysfunction. Dab1 cKO mice exhibited behavioral abnormalities, including hyperactivity, decreased anxiety-like behavior, and impairment of working memory, which are reminiscent of symptoms observed in patients with psychiatric disorders such as schizophrenia and bipolar disorder. These results suggest that deficiency of Reelin-Dab1 signal in the dorsal forebrain is involved in the pathogenesis of some symptoms of human psychiatric disorders.
Assuntos
Comportamento Animal/fisiologia , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Transtornos Mentais/genética , Transtornos Mentais/fisiopatologia , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/metabolismo , Serina Endopeptidases/metabolismo , Transdução de Sinais/fisiologia , Adaptação Fisiológica/genética , Animais , Modelos Animais de Doenças , Comportamento Exploratório/fisiologia , Medo/psicologia , Hipocampo/metabolismo , Hipocampo/patologia , Resposta de Imobilidade Tônica/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/etiologia , Transtornos da Memória/genética , Transtornos Mentais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora/genética , Proteínas do Tecido Nervoso/genética , Proteína Reelina , Reflexo de Sobressalto/genéticaRESUMO
Intraepithelial lymphocytes (IELs) are present in the intestinal epithelium. Mechanisms of IELs for the protection of villi from foreign antigens and from infections by micro-organisms have not been sufficiently explained. Although more than 70% of mouse duodenal and jejunal IELs bear γδTCR (γδIELs), the functions of γδIELs are little investigated. We stimulate γδIELs by anti-CD3 monoclonal antibody (mAb) injection. The mAb activates γδIELs to release Granzyme B (GrB) into the spaces surrounding the γδIELs and intestinal villous epithelial cells (IECs). Released GrB induces DNA fragmentation in IECs independently of Perforin (Pfn). IECs immediately repair their fragmented DNA. Activated IELs reduce their cell size, remain for some time in the epithelium after the activation and are ultimately eliminated without leaving the site. We focus our attention on the response of IELs to the released GrB present in the gap surrounding IELs, after activation, in order to examine whether the released GrB has a similar effect on IELs to that observed on IECs in our previous studies. DNA fragmentation is also induced in IELs together with the repair of fragmented DNA thereafter. The time-kinetics of both events were found to be identical to those observed in IECs. DNA fragmentation in IELs is Pfn-independent. Here, we present Pfn-independent "autocrine DNA fragmentation" in IELs and the repair of fragmented DNA in IELs and discuss their biological significance. Autocrine DNA fragmentation has never been reported to date in vivo.
Assuntos
Comunicação Autócrina , Fragmentação do DNA , Granzimas/metabolismo , Mucosa Intestinal/citologia , Intestino Delgado/citologia , Linfócitos/citologia , Perforina/metabolismo , Animais , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Ativação Linfocitária/imunologia , Linfócitos/metabolismo , Camundongos Endogâmicos BALB CRESUMO
Intraepithelial lymphocytes (IELs) have been considered to play a key role in the defense system of the small intestine. Its mechanism has not been made sufficiently clear. Studies on IELs have been extremely limited to functions of αß T-cell receptor (αßTCR) IELs (αß-IELs). Since, in the mouse duodenum and jejunum, γδ-IELs consist 75 % of IELs, it thus would be inappropriate to argue the mechanism without extensive discussions over the functions of γδ-IELs. In previous studies, we found that the anti-CD3 monoclonal antibody (mAb) injection induced DNA fragmentation in intestinal epithelial cells (IECs) and DNA repair immediately after, that these responses were reproduced by anti-γδTCR mAb not by anti-αßTCR mAb and that the DNA fragmentation was induced by Granzyme B secreted by IELs, totally independent of Perforin. To further explore the functions of IELs in situ, we undertook experiments exclusively focused on IELs, on their changes and ultimate fate after the stimulation in mouse in vivo system. The current study demonstrated that the injected anti-CD3 mAb bound to CD3 on IELs, that the mAb activated γδ-IELs, leading to their degranulation, that changes occurred irreversibly in IELs and finally that activated IELs died in situ. γδ-IELs could be considered to respond to various stimulations most likely without the need of accessory cells ("always ready for rapid response"), to die in situ ("disposable") and thus to respond to the stimulation only once ("a one-shot responder"). These characteristics of γδ-IELs are important to further elucidate the functions of γδ-IELs in the intestinal defense system.
Assuntos
Biomarcadores/metabolismo , Linhagem da Célula , Forma Celular , Células Epiteliais/citologia , Ativação Linfocitária/imunologia , Linfócitos/citologia , Linfócitos/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/farmacologia , Complexo CD3/metabolismo , Contagem de Células , Morte Celular , Células Epiteliais/ultraestrutura , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Jejuno/citologia , Linfócitos/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Coloração e RotulagemRESUMO
We previously found that an i.p. injection of anti-CD3 monoclonal antibody (mAb) into mice caused DNA fragmentation in the intestinal villous epithelial cells (IVECs) of the duodenum and the jejunum. In this study, in order to elucidate the mechanism of DNA fragmentation in IVECs, we searched for the inducer(s) of DNA fragmentation by using immunohistochemistry. The release of cytoplasmic granules from intraepithelial lymphocytes (IELs) and the formation of large gaps between IELs and IVECs were observed electron microscopically after antibody administration. The presence and distribution pattern of Granzyme B (GrB), a serine protease in cytolytic granules present in cytotoxic T lymphocytes and natural killer cells and considered to be the responsible molecule for DNA fragmentation in target cells, was examined in detail in intestinal villi by immunohistology. GrB was detected in cytoplasmic granules in nearly all IELs. The time-kinetics of granule release from IELs after mAb injection coincided not only with that of the extracellular diffusion of GrB, but also with that of DNA fragmentation in IVECs. On the other hand, perforin (Pfn), assumed to cooperate with GrB in DNA fragmentation, could not be detected in IELs, and its release was not confirmed after the anti-CD3 mAb injection. Anti-CD3 mAb injection also induced DNA fragmentation in IVECs in Pfn-knockout mice. These results support the notion that DNA fragmentation in IVECs by the stimulated IELs in the present study is induced by a mechanism involving GrB, but independent of Pfn.
Assuntos
Anticorpos Monoclonais/farmacologia , Complexo CD3/imunologia , Fragmentação do DNA , Granzimas/metabolismo , Mucosa Intestinal/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Perforina/metabolismo , Animais , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Granzimas/genética , Mucosa Intestinal/efeitos dos fármacos , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Perforina/genética , GravidezRESUMO
The arrival and departure dates and the daily maximum populations of migrating swans (Cygnus cygnus) on the Asadokoro tidal flat, Hiranai town, Aomori Prefecture, Japan, were recorded by elementary school students for more than 50 years between 1956 and 2010. The Asadokoro tidal flat, which lies along the coast of Mutsu Bay, has been designated a National Special Natural Monument, known as "The swans of Kominato and their migration grounds." This long history of observation unfortunately came to an end with the closure of the elementary school in 2012. If analyzed together with data on environmental factors, such as temperature changes or the effects of avian influenza, this dataset could provide a potentially valuable source of information, and consequently, future secondary use of the data is anticipated.
RESUMO
This study aimed to explore morphology changes in the kidneys of Dab1-/- (yotari) mice, as well as expression patterns of reelin, NOTCH2, LC3B, and cleaved caspase3 (CASP3) proteins, as potential determinants of normal kidney formation and function. We assumed that Dab1 functional inactivation may cause disorder in a wide spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). Animals were sacrificed at postnatal days P4, P11, and P14. Paraffin-embedded kidney tissues were sectioned and analyzed by immunohistochemistry using specific antibodies. Kidney specimens were examined by bright-field, fluorescence, and electron microscopy. Data were analyzed by two-way ANOVA and t-tests. We noticed that yotari kidneys were smaller in size with a reduced diameter of nephron segments and thinner cortex. TEM microphotographs revealed foot process effacement in the glomeruli (G) of yotari mice, whereas aberrations in the structure of proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) were not observed. A significant increase in reelin expression, NOTCH2, LC3B and cleaved CASP3 proteins was observed in the glomeruli of yotari mice. Renal hypoplasia in conjunction with foot process effacement and elevation in the expression of examined proteins in the glomeruli revealed CAKUT phenotype and loss of functional kidney tissue of yotari.
Assuntos
Proteínas do Tecido Nervoso/genética , Fenótipo , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/genética , Animais , Caspase 3/genética , Caspase 3/metabolismo , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Genes Recessivos , Homozigoto , Córtex Renal/metabolismo , Córtex Renal/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Néfrons/metabolismo , Néfrons/ultraestrutura , Proteínas do Tecido Nervoso/metabolismo , Receptor Notch2/genética , Receptor Notch2/metabolismo , Proteína Reelina , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Anormalidades Urogenitais/metabolismo , Anormalidades Urogenitais/patologia , Refluxo Vesicoureteral/metabolismo , Refluxo Vesicoureteral/patologiaRESUMO
We developed a new kit to assemble three-dimensional (3D) tactile maps for orientation and mobility (O&M) training provided to persons with visual impairments. This study evaluated the effects of verbal explanations combined with 3D tactile map kits in improving understanding, recall, and walking along an unfamiliar route in comparison with the effects of only verbal explanation. The 3D tactile maps provided participants having severe visual impairments and little experience with tactile maps with a better understanding and recall of the environmental information concerning the route and landmarks. Participants who used the 3D tactile maps could find specific landmarks set as tasks more accurately and arrive at the destination alone getting lost less frequently. Tactile maps composed of 3D points, lines, and areal parts are useful as a support aid for O&M training because they have high tactile readability and can provide the environmental information that individuals with visual impairment require.
Assuntos
Mapas como Assunto , Orientação/fisiologia , Tecnologia Assistiva , Auxiliares Sensoriais , Percepção do Tato/fisiologia , Transtornos da Visão/reabilitação , Adulto , Planejamento Ambiental , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Navegação Espacial/fisiologia , Aprendizagem Verbal/fisiologia , Caminhada/psicologiaRESUMO
To effectively use a common marmoset (Callithrix jacchus) as an experimental animal species, it is critical to establish a normal characteristics and morphology of the organs of the common marmoset. Although gross morphology of the common marmoset heart is reportedly the same as that of humans, little information is available regarding detailed morphology of the right atrium and the interatrial septum. Heart specimens were collected from three male and 10 female marmosets aged 9 to 65 months to determine the morphological features of the right atrium and the interatrial septum. Ten specimens were evaluated morphologically with a stereoscopic microscope in accordance with preparation and investigation methods designed to facilitate evaluation. Three specimens were histologically evaluated after being stained with hematoxylin-eosin, Elastica van Gieson and periodic acid Schiff. An annular ridge that is not present in the human heart was present in the right atrium and the interatrial septum of the common marmoset hearts. Tissue structure of the annular ridge was similar to atrial myocardial fibers. Furthermore, location of the coronary sinus ostium was different to that in humans. Present findings were used to create a schematic view of the annular ridge in the common marmoset heart. In the common marmoset heart, the annular ridge may function as a valve of the superior vena cava ostium, inferior vena cava ostium, and coronary sinus ostium. Present study provides morphological evidence that common marmosets have a valve-like structure in the right atrium.
Assuntos
Callithrix/anatomia & histologia , Seio Coronário/anatomia & histologia , Septos Cardíacos/anatomia & histologia , Animais , Átrios do Coração/anatomia & histologiaRESUMO
In our earlier work, we found that, in mice, i.p. injection of anti-CD3 monoclonal antibody activated intraepithelial lymphocytes (iIEL), leading to DNA fragmentation in villous epithelial cells of the duodenum and jejunum within 30 min. By 2 h after injection, nearly half of the enterocytes had detached from the villi, and DNA fragmentation could barely be detected in the remaining villous epithelium. We hypothesized that DNA had been repaired in enterocytes in which DNA fragmentation had previously been induced. In this study, enterocytes became negative for TUNEL staining at 60 min after anti-CD3 treatment, prior to detachment. The remaining villous epithelial cells, after DNA fragmentation and detachment, were found to be positive for 5-bromo-2-deoxyuridine labeling. To confirm whether fragmented DNA had been repaired in situ, we investigated the appearance and/or mobilization of DNA-repair-related proteins. Focus formation, a typical staining pattern of repair-related proteins including phosphorylated H2AX, phospo-ATM substrate, and Nbs1, was observed 30 min after anti-CD3 injection, with the kinetics virtually identical to that of DNA fragmentation. The co-localization of gamma-H2AX and phospo-ATM substrate was also confirmed. The disappearance of a positive reaction for TUNEL staining in previously fragmented DNA, the appearance of representative DNA-repair-related proteins, the coincidence of the kinetics of DNA fragmentation and this appearance of DNA-repair-related proteins, and the co-localization of two of the repair-related proteins strongly indicated that enterocyte DNA could be repaired after it had been fragmented in vivo. Thus, DNA fragmentation per se may not necessarily be an immediate sign of cell death.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Fragmentação do DNA , Reparo do DNA , Enterócitos/metabolismo , Histonas/metabolismo , Jejuno/metabolismo , Proteínas Nucleares/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Proteínas de Ligação a DNA , Enterócitos/efeitos dos fármacos , Enterócitos/ultraestrutura , Feminino , Jejuno/efeitos dos fármacos , Jejuno/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de TransmissãoRESUMO
Lipids are major molecules for the function of organisms and are involved in the pathophysiology of various diseases. Fatty acids (FAs) signaling and their metabolism are some of the most important pathways in tumor development, as lipids serve as energetic sources during carcinogenesis. Fatty acid binding proteins (FABPs) facilitate FAs transport to different cell organelles, modulating their metabolism along with mediating other physiological activities. FABP7, brain-typed FABP, is thought to be an important molecule for cell proliferation in healthy as well as diseased organisms. Several studies on human tumors and tumor-derived cell lines put FABP7 in the center of tumorigenesis, and its high expression level has been reported to correlate with poor prognosis in different tumor types. Several types of FABP7-expressing tumors have shown an up-regulation of cell signaling activity, but molecular mechanisms of FABP7 involvement in tumorigenesis still remain elusive. In this review, we focus on the expression and function of FABP7 in different tumors, and possible mechanisms of FABP7 in tumor proliferation and migration.
Assuntos
Proliferação de Células , Proteína 7 de Ligação a Ácidos Graxos/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Neoplasias/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/biossíntese , Animais , Proteína 7 de Ligação a Ácidos Graxos/genética , Humanos , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/patologia , Proteínas Supressoras de Tumor/genéticaRESUMO
Fatty acid binding protein 7 (FABP7) is expressed in astrocytes of the developing and mature central nervous system, and modulates astrocyte function by controlling intracellular fatty acid homeostasis. Astrocytes in the spinal cord have an important role in the process of myelin degeneration and regeneration. In the present study, the authors examined the role of FABP7 in astrocytes in a mouse model of experimental autoimmune encephalomyelitis (EAE), which is an established model of multiple sclerosis (MS). FABP7 was expressed in the white matter astrocytes and increased after EAE onset; particularly strong expression was observed in demyelinating regions. In FABP7-knockout (KO) mice, the onset of EAE symptoms occurred earlier than in wild type (WT) mice, and mRNA expression levels of inflammatory cytokines (IL-17 and TNF-α) were higher in FABP7-KO lumbar spinal cord than in WT lumbar spinal cord at early stage of EAE. Interestingly, however, the clinical score was significantly reduced in FABP7-KO mice compared with WT mice in the late phase of EAE. Moreover, the area exhibiting expression of fibronectin, which is an extracellular matrix protein mainly produced by astrocytes and inhibits remyelination of oligodendrocytes, was significantly decreased in FABP7-KO compared with WT mice. Collectively, FABP7 in astrocyte may have a role to protect from the induction of inflammation leading to demyelination in CNS at early phase of EAE. Moreover, FABP7 may be involved in the regulation of fibronectin production through the modification of astrocyte activation at late phase of EAE.
Assuntos
Astrócitos/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/metabolismo , Medula Espinal/metabolismo , Animais , Citocinas/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/genética , Feminino , Fibronectinas/metabolismo , Camundongos , Camundongos Knockout , Bainha de Mielina/metabolismo , Substância Branca/metabolismoRESUMO
With the goal of understanding the role of non-homologous end-joining repair in the maintenance of genetic information at the tissue level, we studied mutations induced by radiation and subsequent repair of DNA double-strand breaks in Ku70 gene-deficient lacZ transgenic mice. The local mutation frequencies and types of mutations were analyzed on a lacZ gene that had been chromosomally integrated, which allowed us to monitor DNA sequence alterations within this 3.1-kbp region. The mutagenic process leading to the development of the most frequently observed small deletions in wild-type mice after exposure to 20 Gy of X rays was suppressed in Ku70(-/-) mice in the three tissues examined: spleen, liver and brain. Examination of DNA break rejoining and the phosphorylation of histone H2AX in Ku70-deficient and -proficient mice revealed that Ku70 deficiency decreased the frequency of DNA rejoining, suggesting that DNA rejoining is one of the causes of radiation-induced deletion mutations. Limited but statistically significant DNA rejoining was found in the liver and brain of Ku70-deficient mice 3.5 days after irradiation, showing the presence of a DNA double-strand break repair system other than non-homologous end joining. These data indicate a predominant role of non-homologous end joining in the production of radiation-induced mutations in vivo.
Assuntos
Antígenos Nucleares/metabolismo , Dano ao DNA/genética , Proteínas de Ligação a DNA/metabolismo , Deleção de Genes , Óperon Lac/genética , Mutagênese/efeitos da radiação , Vísceras/metabolismo , Vísceras/efeitos da radiação , Animais , Antígenos Nucleares/genética , Proteínas de Ligação a DNA/genética , Relação Dose-Resposta à Radiação , Autoantígeno Ku , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Mutagênese/genética , Doses de Radiação , Raios XRESUMO
Thymocytes are thought to be selected on the basis of antigen specificity between TCR and peptide-MHC (pMHC) ligands. The specificity depends primarily on extensive diversities of complementarity determining region 3 (CDR3), whose specificity is considered to be determined through thymocyte selection. We examined the CDR3 length profiles with 20 BV segments in thymocyte subpopulations from C57BL/6 (H-2(b)), C.B10 (Balb/c congenic, H-2(b)) and Balb/c (H-2(d)) mice. The CDR3 length was shorter in both CD4 single positive (SP) and CD8SP than in double positive (DP), but not altered among DP, double negative (DN) 4 and DN3 subpopulations. The CDR3 shortened more prominently in CD4SP than in CD8SP for C57BL/6 and C.B10, but the shortening was only slight for Balb/c. Although the shortening varied considerably among different BV segments, the greater shortening was observed in most BV segments for CD4SP and in several for CD8SP, in particular, the extent was the greatest in BV1, BV2, BV15, BV16, BV23 and BV26 for CD4SP, and in BV13-1 and BV29 for CD8SP. Moreover, the extent and the pattern of CDR3 shortening were basically the same among highly homologous BV segments (e.g. BV12-1 and 12-2; BV13-1, 13-2 and 13-3). These results taken together indicate that (1) the CDR3 shortening occurred between the DP to the SP stages but never earlier, that (2) there would be the MHC class preference for the CDR3 shortening, that (3) it was in part influenced by MHC haplotype, and finally that (4) the primary structure of particular BV segments would possibly affect the CDR3 length in selected thymocytes. It could be deduced from these results that the CDR3 shortening might play roles in ensuring geometrical disposition of CDRs unique to each BV segment and consequently allow CDRs to intimately interact with pMHC ligands.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Regiões Determinantes de Complementaridade/química , Receptores de Antígenos de Linfócitos T/química , Timo/citologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regiões Determinantes de Complementaridade/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/imunologia , Timo/imunologiaRESUMO
The hypothalamus is involved in the regulation of food intake and energy homeostasis. The arcuate nucleus (ARC) and median eminence (ME) are the primary hypothalamic sites that sense leptin and nutrients in the blood, thereby mediating food intake. Recently, studies demonstrating a role for non-neuronal cell types, including astrocytes and tanycytes, in these regulatory processes have begun to emerge. However, the molecular mechanisms involved in these activities remain largely unknown. In this study, we examined in detail the localization of fatty acid-binding protein 7 (FABP7) in the hypothalamic ARC and sought to determine its role in the hypothalamus. We performed a phenotypic analysis of diet-induced FABP7 knockout (KO) obese mice and of FABP7 KO mice treated with a single leptin injection. Immunohistochemistry revealed that FABP7+ cells are NG2+ or GFAP+ in the ARC and ME. In mice fed a high-fat diet, weight gain and food intake were lower in FABP7 KO mice than in wild-type (WT) mice. FABP7 KO mice also had lower food intake and weight gain after a single injection of leptin, and we consistently confirmed that the number of pSTAT3+ cells in the ARC indicated that the leptin-induced activation of neurons was significantly more frequent in FABP7 KO mice than in WT mice. In FABP7 KO mice-derived primary astrocyte cultures, the level of ERK phosphorylation was lower after leptin treatment. Collectively, these results indicate that in hypothalamic astrocytes, FABP7 might be involved in sensing neuronal leptin via glia-mediated mechanisms and plays a pivotal role in controlling systemic energy homeostasis.
Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/metabolismo , Leptina/farmacologia , Neuroglia/metabolismo , Neurônios/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Células Cultivadas , Dieta Hiperlipídica , Ingestão de Alimentos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Fosforilação/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Aumento de Peso/efeitos dos fármacosRESUMO
Mitochondrial dysfunction increases oxidative stress and depletes ATP in a variety of disorders. Several antioxidant therapies and drugs affecting mitochondrial biogenesis are undergoing investigation, although not all of them have demonstrated favorable effects in the clinic. We recently reported a therapeutic mitochondrial drug mitochonic acid MA-5 (Tohoku J. Exp. Med., 2015). MA-5 increased ATP, rescued mitochondrial disease fibroblasts and prolonged the life span of the disease model "Mitomouse" (JASN, 2016). To investigate the potential of MA-5 on various mitochondrial diseases, we collected 25 cases of fibroblasts from various genetic mutations and cell protective effect of MA-5 and the ATP producing mechanism was examined. 24 out of the 25 patient fibroblasts (96%) were responded to MA-5. Under oxidative stress condition, the GDF-15 was increased and this increase was significantly abrogated by MA-5. The serum GDF-15 elevated in Mitomouse was likewise reduced by MA-5. MA-5 facilitates mitochondrial ATP production and reduces ROS independent of ETC by facilitating ATP synthase oligomerization and supercomplex formation with mitofilin/Mic60. MA-5 reduced mitochondria fragmentation, restores crista shape and dynamics. MA-5 has potential as a drug for the treatment of various mitochondrial diseases. The diagnostic use of GDF-15 will be also useful in a forthcoming MA-5 clinical trial.
Assuntos
Ácidos Indolacéticos/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Doenças Mitocondriais/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Fenilbutiratos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Biomarcadores , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , DNA Mitocondrial , Modelos Animais de Doenças , Fatores de Crescimento de Fibroblastos/metabolismo , Fibroblastos/metabolismo , Fator 15 de Diferenciação de Crescimento/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/genética , Doenças Mitocondriais/diagnóstico , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/genética , Dinâmica Mitocondrial/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/química , Complexos Multiproteicos/metabolismo , Mutação , Biogênese de Organelas , Prognóstico , Substâncias Protetoras , Ligação ProteicaRESUMO
Although many studies of intraepithelial lymphocytes (IELs) have been reported, most of them have focused on αß-IELs; little attention has been paid to γδ-IELs. The function of γδ-IELs remains largely unclear. In this article, we briefly review a number of reports on γδ-IELs, especially those in the small intestine, along with our recent studies. We found that γδ-IELs are the most abundant (comprising >70 % of the) IELs in the duodenum and the jejunum, implying that it is absolutely necessary to investigate the function(s) of γδ-IELs when attempting to delineate the in vivo defense system of the small intestine. Intraperitoneal injection of anti-CD3 mAb stimulated the γδ-IELs and caused rapid degranulation of them. Granzyme B released from their granules induced DNA fragmentation of duodenal and jejunal epithelial cells (paracrine) and of the IELs themselves (autocrine). However, perforin (Pfn) was not detected, and DNA fragmentation was induced even in Pfn-knockout mice; our system was therefore found to present a novel type of in vivo Pfn-independent DNA fragmentation. We can therefore consider γδ-IELs to be a novel type of large granular lymphocyte without Pfn. Fragmented DNA was repaired in the cells, indicating that DNA fragmentation alone cannot be regarded as an unambiguous marker of cell death or apoptosis. Finally, since the response was so rapid and achieved without the need for accessory cells, it seems that γδ-IELs respond readily to various stimuli, are activated only once, and die 2-3 days after activation in situ without leaving their site. Taken together, these results suggest that γδ-IELs are not involved in the recognition of specific antigen(s) and are not involved in the resulting specific killing or exclusion of the relevant antigen(s).
Assuntos
Células Epiteliais , Intestino Delgado/citologia , Linfócitos/imunologia , Camundongos/anatomia & histologia , Animais , Anticorpos Monoclonais/imunologia , Complexo CD3/imunologia , Morte Celular , Degranulação Celular , Fragmentação do DNA , Células Epiteliais/imunologia , Granzimas , Intestino Delgado/imunologia , Ativação Linfocitária , PerforinaRESUMO
Cellular metabolic changes, especially to lipid metabolism, have recently been recognized as a hallmark of various cancer cells. However, little is known about the significance of cellular lipid metabolism in the regulation of biological activity of glioma stem cells (GSCs). In this study, we examined the expression and role of fatty acid synthase (FASN), a key lipogenic enzyme, in GSCs. In the de novo lipid synthesis assay, GSCs exhibited higher lipogenesis than differentiated non-GSCs. Western blot and immunocytochemical analyses revealed that FASN is strongly expressed in multiple lines of patient-derived GSCs (G144 and Y10), but its expression was markedly reduced upon differentiation. When GSCs were treated with 20 µM cerulenin, a pharmacological inhibitor of FASN, their proliferation and migration were significantly suppressed and de novo lipogenesis decreased. Furthermore, following cerulenin treatment, expression of the GSC markers nestin, Sox2 and fatty acid binding protein (FABP7), markers of GCSs, decreased while that of glial fibrillary acidic protein (GFAP) expression increased. Taken together, our results indicate that FASN plays a pivotal role in the maintenance of GSC stemness, and FASN-mediated de novo lipid biosynthesis is closely associated with tumor growth and invasion in glioblastoma.
Assuntos
Ácido Graxo Sintases/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioma/enzimologia , Glioma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cerulenina/farmacologia , Ácido Graxo Sintases/antagonistas & inibidores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/citologia , Células Tumorais CultivadasRESUMO
Although the benefits of carvedilol in patients with heart failure and depressed ejection fraction (EF) have been elucidated, those in patients with preserved EF are not understood. We enrolled 40 patients with mild or moderate heart failure and EF >/=45%. They were randomly assigned to carvedilol (n = 19) or conventional therapy (n = 21). After 12 months of treatment, carvedilol significantly improved all end points (plasma concentration of B-type natriuretic peptide [BNP] from 175 (35 to 209) to 106 (52 to 160) pg/ml, mean (95% confidence interval) p <0.01; New York Heart Association functional class from 2.37 (2.13 to 2.61) to 1.56 (1.21 to 1.91), p <0.01; exercise capacity estimated with the Specific Activity Scale from 4.75 (4.50 to 5.00) to 5.68 (5.22 to 6.14) METs, p <0.02), whereas conventional therapy did not (plasma BNP concentration from 150 (114 to 186) to 174 (100 to 248) pg/ml; New York Heart Association functional class from 2.29 (2.08 to 2.50) to 2.11 (1.73 to 2.49); exercise capacity from 4.57 (4.34 to 4.80) to 4.72 (4.41 to 5.03) METs). Univariate regression analyses showed that only the use of carvedilol was correlated with the decrease in plasma BNP concentration (p <0.03). Multivariate analyses demonstrated that an ischemic cause of heart failure (p <0.02), high plasma concentration of BNP (p <0.02), left ventricular dilation (p <0.03), and use of carvedilol (p <0.04) at baseline were predictive of a decrease in plasma concentration of BNP. In conclusion, carvedilol potentially decreased neurohumoral activation, decreased symptoms, and increased exercise capacity in patients with heart failure and preserved EF.