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1.
Phys Chem Chem Phys ; 22(3): 1137-1144, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31774080

RESUMO

Disulfide bonds play a fundamental role in controlling the tertiary structure of proteins; the formation or cleavage of some disulfide bonds can switch the structures and/or functions of proteins. Human galectin-1 (hGal-1), which is a lectin protein, exemplifies how both structure and function are changed by disulfide bonds; the structure and sugar-binding ability of hGal-1 are altered by the formation and cleavage of its three intra-molecular disulfide bonds. In the present study, the dynamics of the structural change of hGal-1 by the formation of disulfide bonds were investigated by time-resolved FTIR spectroscopy combined with a modification in which its thiol groups (-SH) were replaced with S-nitrosylated groups (SNO). Photodissociation of NO from SNO in reduced hGal-1 induced disulfide bond formation and transformed it into the oxidised form. The structural change to the oxidised form involved three distinct kinetics with fast (<300 s), middle (∼600 s), and slow (∼6400 s) lifetimes. In an examination of hGal-1 in the lactose-bound form, structural changes owing to the release of substrate lactose were also observed upon disulfide bond formation. The present method using the photodissociation of NO is useful for monitoring the dynamics of structural changes following disulfide formation.


Assuntos
Galectina 1/química , Modelos Moleculares , Espectroscopia de Infravermelho com Transformada de Fourier , Dissulfetos/química , Humanos , Luz , Estrutura Terciária de Proteína/efeitos da radiação
2.
Analyst ; 144(23): 6858-6861, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31663589

RESUMO

A highly lipophilic ionic liquid (IL) consisting of stoichiometrically equal amounts of two purely functional chemical sensing molecules, an anionic calcium ionophore and a cationic dye, was synthesized for the first time, and used as a component for a poly(vinyl chloride)-based or neat liquid membrane optical sensor. This is the first report of an IL consisting of purely functional chemical sensing molecules, which is completely different from the previously reported ionic liquids typically consisting of imidazolium or other lipophilic cations. Since the present IL contained an extremely high concentration of dyes, the IL-based sensor showed dramatically enhanced sensitivity (13 times higher compared to that of a conventional sensor), and fully reversible and selective response to Ca2+. Preliminary investigation on the unique response characteristics of the present liquid membrane IL-based sensor was performed with the responses to Ca2+ and Na+.

3.
BMC Cancer ; 12: 448, 2012 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-23031214

RESUMO

BACKGROUND: Chemotherapeutic bioassay for colorectal cancer (CRC) with a rat model bearing chemically-induced CRCs plays an important role in the development of new anti-tumor drugs and regimens. Although several protocols to induce CRCs have been developed, the incidence and number of CRCs are not much enough for the efficient bioassay. Recently, we established the very efficient system to induce CRCs with a chemically induced-colon carcinogenesis-prone Apc-mutant rat, Kyoto Apc Delta (KAD) rat. Here, we applied the KAD rat to the chemotherapeutic bioassay for CRC and showed the utility of the KAD rat. METHODS: The KAD rat has been developed by the ENU mutagenesis and carries a homozygous nonsense mutation in the Apc gene (S2523X). Male KAD rats were given a single subcutaneous injection of AOM (20 mg/kg body weight) at 5 weeks of age. Starting at 1 week after the AOM injection, they were given 2% DSS in drinking water for 7 days. Tumor-bearing KAD rats were divided into experimental and control groups on the basis of the number of tumors observed by endoscopy at week 8. The 5-fluorouracil (5-FU) was administrated intravenously a dose of 50 or 75 mg/kg weekly at week 9, 10, and 11. After one-week interval, the 5-FU was given again at week 13, 14, and 15. At week 16, animals were sacrificed and tumor number and volume were measured macroscopically and microscopically. RESULTS: In total 48 tumors were observed in 27 KAD rats with a 100% incidence at week 8. The maximum tolerated dose for the KAD rat was 50 mg/kg of 5-FU. Macroscopically, the number or volume of tumors in the 5-FU treated rats was not significantly different from the control. Microscopically, the number of adenocarcinoma in the 5-FU treated rats was not significantly different (p < 0.02) from that of the control. However, the volume of adenocarcinomas was significantly lower than in the control. Anticancer effect of the 5-FU could be obtained only after the 16 weeks of experimental period. CONCLUSION: The use of the AOM/DSS-treated tumor-bearing KAD rats could shorten the experimental period and reduce the number of animals examined in the chemotherapeutic bioassay. The efficient bioassay with the AOM/DSS-treated tumor-bearing KAD rats would promote the development of new anti-tumor drugs and regimens.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Fluoruracila/farmacologia , Mutação , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacologia , Azoximetano , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias do Colo/induzido quimicamente , Sulfato de Dextrana , Relação Dose-Resposta a Droga , Esquema de Medicação , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Fluoruracila/administração & dosagem , Injeções Intravenosas , Masculino , Ratos , Reprodutibilidade dos Testes
4.
J Allergy Clin Immunol ; 128(5): 1067-76.e1-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21794904

RESUMO

BACKGROUND: IL-22 functions as both a proinflammatory cytokine and an anti-inflammatory cytokine in various inflammations, depending on the cellular and cytokine milieu. However, the roles of IL-22 in the regulation of allergic airway inflammation are still largely unknown. OBJECTIVE: We sought to determine whether IL-22 is involved in the regulation of allergic airway inflammation. METHODS: We examined IL-22 production and its cellular source at the site of antigen-induced airway inflammation in mice. We also examined the effect of IL-22 neutralization, as well as IL-22 administration, on antigen-induced airway inflammation. We finally examined the effect of IL-22 on IL-25 production from a lung epithelial cell line (MLE-15 cells). RESULTS: Antigen inhalation induced IL-22 production in the airways of sensitized mice. CD4(+) T cells, but not other lymphocytes or innate cells, infiltrating in the airways produced IL-22, and one third of IL-22-producing CD4(+) T cells also produced IL-17A. The neutralization of IL-22 by anti-IL-22 antibody enhanced antigen-induced IL-13 production, eosinophil recruitment, and goblet cell hyperplasia in the airways. On the other hand, intranasal administration of recombinant IL-22 attenuated antigen-induced eosinophil recruitment into the airways. Moreover, anti-IL-22 antibody enhanced antigen-induced IL-25 production in the airways, and anti-IL-25 antibody reversed the enhancing effect of anti-IL-22 antibody on antigen-induced eosinophil recruitment into the airways. Finally, IL-22 inhibited IL-13-mediated enhancement of IL-25 expression in IL-1ß- or LPS-stimulated MLE-15 cells. CONCLUSION: IL-22 attenuates antigen-induced airway inflammation, possibly by inhibiting IL-25 production by lung epithelial cells.


Assuntos
Asma/imunologia , Eosinofilia/imunologia , Células Epiteliais/imunologia , Interleucinas/imunologia , Pneumonia/imunologia , Mucosa Respiratória/imunologia , Animais , Asma/metabolismo , Western Blotting , Líquido da Lavagem Broncoalveolar/imunologia , Modelos Animais de Doenças , Eosinofilia/metabolismo , Células Epiteliais/metabolismo , Imuno-Histoquímica , Interleucinas/biossíntese , Interleucinas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Pneumonia/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Mucosa Respiratória/metabolismo , Interleucina 22
5.
Biocontrol Sci ; 17(1): 17-25, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22451428

RESUMO

The anti-influenza virus activity of fossilized marine coral powder (sango mineral powder, SMP) was studied. SMP is composed in terms of mass of around 25 % of calcium and 10 % of magnesium, respectively, principally as dolomite (CaMg(CO(3))(2)) but not as calcium oxide (CaO) or magnesium oxide (MgO). By mixing the influenza virus with SMP, the infectivity of the virus substantially decreased and there was more than a 10(4) reduction on the 3rd d of infection. The antiviral effect was observed against all the type A and B strains of the influenza virus examined including the H1N1 2009 pandemic and H5N1 avian viruses. The surface structure of SMP was highly porous and the anti-influenza activity was explained by the adsorption of the viral particles onto its surface. The binding of viruses to SMP was strong and stable in the physiological condition, and the attached viruses detached only in the presence of a high concentration of phosphate. This was similar to the binding of protein to hydroxyapatite, suggesting an ionic interaction between SMP and the viral proteins. SMP maintained its activity to capture influenza viruses even after being immobilized on a non-woven textile. SMP would be useful as a practical anti-influenza tool especially in preparation for the next pandemic virus.


Assuntos
Antozoários , Antivirais/farmacologia , Minerais/farmacologia , Orthomyxoviridae/efeitos dos fármacos , Adsorção , Animais , Células Cultivadas , Cães , Orthomyxoviridae/crescimento & desenvolvimento , Tamanho da Partícula , Pós
6.
J Clin Med ; 11(13)2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35806959

RESUMO

The dextran sodium sulfate (DSS)-induced colitis mouse model has been widely utilized for human colitis research. While its mechanism involves a response to double-strand deoxyribonucleic acid (DNA) damage, ataxia telangiectasia mutated (Atm)-checkpoint kinase 2 (Chk2) pathway activation related to such response remains unreported. Recently, we reported that cyclin D1-binding protein 1 (Ccndbp1) activates the pathway reflecting DNA damage in its knockout mice. Thus, this study aimed to examine the contribution of Ccndbp1 and the Atm-Chk2 pathway in DSS-induced colitis. We assessed the effect of DSS-induced colitis on colon length, disease activity index, and histological score and on the Atm-Chk2 pathway and the subsequent apoptosis in Ccndbp1-knockout mice. DSS-induced colitis showed distal colon-dominant Atm and Chk2 phosphorylation, increase in TdT-mediated dUTP-biotin nick end labeling and cleaved caspase 3-positive cells, and histological score increase, causing disease activity index elevation and colon length shortening. These changes were significantly ameliorated in Ccndbp1-knockout mice. In conclusion, Ccndbp1 contributed to Atm-Chk2 pathway activation in the DSS-induced colitis mouse model, causing inflammation and apoptosis of mucosal cells in the colon.

7.
Clin J Gastroenterol ; 15(2): 381-387, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35064919

RESUMO

Gastrointestinal duplications are congenital malformations that are usually observed in pediatric patients. Diagnosis in adulthood is quite rare, and preoperative diagnosis of gastrointestinal duplication is difficult, particularly in the small intestine. We encountered an extremely rare adult case of duplication of the jejunum, which showed a stomach-like form diagnosed using double-balloon enteroscopy (DBE). The patient was an 18-year-old male who had been experiencing upper abdominal pain and vomiting repeatedly without any triggers for 3 years. Various examinations were performed, but no cause of symptoms was found. DBE revealed a narrow opening of the lumen at the upper jejunum, and the lumen was covered with mucosal folds similar to those of the stomach. Enteroclysis via DBE showed a tubular structure on the mesenteric side of the jejunum. We diagnosed a jejunal tubular duplication with ectopic gastric mucosa and underwent partial small bowel resection. The patient's abdominal symptoms resolved. From this, DBE can be a useful tool for diagnosing intestinal duplication in adults. We believe that this case and literature review will facilitate the accurate and prompt diagnosis of small intestinal duplication.


Assuntos
Enteroscopia de Duplo Balão , Enteropatias , Adolescente , Adulto , Biópsia , Criança , Humanos , Enteropatias/cirurgia , Intestino Delgado/cirurgia , Jejuno/cirurgia , Masculino
8.
J Clin Med ; 11(3)2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35160302

RESUMO

Cyclin D1 binding protein 1 (CCNDBP1) is considered a tumor suppressor, and when expressed in tumor cells, CCNDBP1 can contribute to the viability of cancer cells by rescuing these cells from chemotherapy-induced DNA damage. Therefore, this study focused on investigating the function of CCNDBP1, which is directly related to the survival of cancer cells by escaping DNA damage and chemoresistance. Hepatocellular carcinoma (HCC) cells and tissues obtained from Ccndbp1 knockout mice were used for the in vitro and in vivo examination of the molecular mechanisms of CCNDBP1 associated with the recovery of cells from DNA damage. Subsequently, gene and protein expression changes associated with the upregulation, downregulation, and irradiation of CCNDBP1 were assessed. The overexpression of CCNDBP1 in HCC cells stimulated cell growth and showed resistance to X-ray-induced DNA damage. Gene expression analysis of CCNDBP1-overexpressed cells and Ccndbp1 knockout mice revealed that Ccndbp1 activated the Atm-Chk2 pathway through the inhibition of Ezh2 expression, accounting for resistance to DNA damage. Our study demonstrated that by inhibiting EZH2, CCNDBP1 contributed to the activation of the ATM-CHK2 pathway to alleviate DNA damage, leading to chemoresistance.

9.
Plant Cell Physiol ; 52(8): 1315-29, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21666227

RESUMO

The plant circadian clock generates rhythms with a period close to 24 h, and it controls a wide variety of physiological and developmental events. Among clock-controlled developmental events, the best characterized is the photoperiodic control of flowering time, which is mediated through the CONSTANS (CO)-FLOWERING LOCUS T (FT) pathway in Arabidopsis thaliana. The clock also regulates the diurnal plant growth including the elongation of hypocotyls in a short day (SDs)-specific manner. In this mechanism, phytochromes (mainly phyB) and the PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and PIF5, encoding phytochrome-interacting basic helix-loop-helix (bHLH) transcription factors, play crucial roles. The time of day-specific and photoperiodic control of hypocotyl elongation is best explained by the accumulation of the PIF4 and PIF5 proteins during night-time before dawn, especially under SDs, due to coincidence between the internal (circadian rhythm) and external (photoperiod) time cues. However, the PIF4- and/or PIF5-controlled downstream factors have not yet been identified. Here, we provide evidence that ARABIDOPSIS THALIANA HOMEOBOX PROTEIN2 (ATHB2), together with auxin-inducible IAA29, is diurnally expressed with a peak at dawn under the control of PIF4 and PIF5 specifically in SDs. This coincidentally expressed transcription factor serves as a positive regulator for the elongation of hypocotyls. The expression profiles of ATHB2 were markedly altered in certain clock and phytochrome mutants, all of which show anomalous phenotypes with regard to the photoperiodic control of hypocotyl elongation. Taken together, we propose that an external coincidence model involving the clock-controlled PIF4/PIF5-ATHB2 pathway is crucial for the diurnal and photoperiodic control of plant growth in A. thaliana.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ácidos Indolacéticos/farmacologia , Fotoperíodo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Relógios Circadianos/efeitos dos fármacos , Relógios Circadianos/genética , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/genética , Escuridão , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Hipocótilo/efeitos dos fármacos , Hipocótilo/crescimento & desenvolvimento , Modelos Biológicos , Mutação/genética , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo
10.
Dis Model Mech ; 14(3)2021 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-33787507

RESUMO

The etiology of non-alcoholic fatty liver disease (NAFLD) consists of various factors, including neural signal pathways. However, the molecular mechanisms of the autonomic neural signals influencing NAFLD progression have not been elucidated. Therefore, we examined the involvement of the gut-liver neural axis in NAFLD development and tested the therapeutic effect of modulation of this axis in this study. To test the contribution of the gut-liver neural axis, we examined NAFLD progression with respect to body weight, hepatic steatosis, fibrosis, intestinal tight junction, microbiota and short-chain fatty acids in NAFLD models of choline-deficient defined L-amino-acid and high-fat diet-fed mice with or without blockades of autonomic nerves from the liver. Blockade of the neural signal from the liver to the gut in these NAFLD mice models ameliorated the progression of liver weight, hepatic steatosis and fibrosis by modulating serotonin expression in the small intestine. It was related to the severity of the liver pathology, the tight junction protein expression, microbiota diversity and short-chain fatty acids. These effects were reproduced by administrating serotonin antagonist, which ameliorated the NAFLD progression in the NAFLD mice models. Our study demonstrated that the gut-liver neural axis is involved in the etiologies of NAFLD progression and that serotonin expression through this signaling network is the key factor of this axis. Therefore, modulation of the gut-liver neural axis and serotonin antagonist ameliorates fatty and fibrotic changes in non-alcoholic fatty liver, and can be a potential therapeutic target of NAFLD.This article has an associated First Person interview with the first author of the paper.


Assuntos
Sistema Nervoso Autônomo/metabolismo , Trato Gastrointestinal/metabolismo , Cirrose Hepática/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Serotonina/metabolismo , Animais , Peso Corporal , Dieta Hiperlipídica , Modelos Animais de Doenças , Microbioma Gastrointestinal , Trato Gastrointestinal/patologia , Fígado/patologia , Cirrose Hepática/patologia , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia , Tamanho do Órgão , Transdução de Sinais , Junções Íntimas/metabolismo
11.
Biosci Microbiota Food Health ; 40(3): 150-155, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34285860

RESUMO

Sarcopenia causes functional disorders and decreases the quality of life. Thus, it has attracted substantial attention in the aging modern world. Dysbiosis of the intestinal microbiota is associated with sarcopenia; however, it remains unclear whether prebiotics change the microbiota composition and result in the subsequent recovery of muscle atrophy in elderly patients with sarcopenia. This study aimed to assess the effects of prebiotics in super-elderly patients with sarcopenia. We analyzed the effects of 1-kestose on the changes in the intestinal microbiota and body composition using a next-generation sequencer and a multi-frequency bioimpedance analysis device. The Bifidobacterium longum population was significantly increased in the intestine after 1-kestose administration. In addition, in all six patients after 12 weeks of 1-kestose administration, the skeletal muscle mass index was greater, and the body fat percentage was lower. This is the first study to show that administration of a prebiotic increased the population of B. longum in the intestinal microbiota and caused recovery of muscle atrophy in super-elderly patients with sarcopenia.

12.
Asia Pac Allergy ; 10(2): e12, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32411577

RESUMO

BACKGROUND: About one-half of all patients with chronic spontaneous urticaria have low or less reactivity of the basophils to FcεRI stimulation. However, the differences in the clinical characteristics between patients who show normal and attenuated basophil reactivities to FcεRI stimulation are still unclear. Furthermore, it also remains unknown as to what factors induce the poor reactivity of basophils to FcεRI stimulation. OBJECTIVE: The aim of the study is to investigate the differences in the clinical characteristics between patients who show normal and attenuated basophil reactivities to FcεRI stimulation. METHODS: We compared the clinical characteristics, including the autologous serum skin test-positive rates, serum concentrations of anti-IgE and anti-FcεRIα autoantibodies, and the FcεRI-crosslinking ability of these autoantibodies between patients with a negative basophil activation test (BAT) (≤10% CD203chigh basophils, n = 9) and positive BAT (>10% CD203chigh basophils, n = 13). We also monitored the changes in the 7-day urticaria activity scores after treatment with omalizumab, as compared to the score at the baseline, between the BAT-positive and BAT-negative patients. RESULTS: The BAT-negative patients showed a significantly higher urticaria control test score than the BAT-positive patients (p = 0.01). There were no significant differences in the autologous serum skin test-positive rates, concentrations of anti-IgE and anti-FcεRIα autoantibodies, and the FcεRI-crosslinking ability of these autoantibodies between the 2 groups. After treatment with omalizumab for 35 days, the score decreased to under 15 (corresponding to controlled or mild chronic spontaneous urticaria) in all of the BAT-negative patients, whereas in 6 out of the 13 BAT-positive patients, the scores remained over 16 (corresponding to moderate or severe chronic spontaneous urticaria). CONCLUSIONS: The weak reactivity of basophils to FcεRI stimulation may not be due to the desensitization of basophils by anti-IgE or anti-FcεRIα autoantibodies. The time to response to omalizumab might differ between BAT-negative and BAT-positive patients with chronic spontaneous urticaria.

13.
Neurogastroenterol Motil ; 32(5): e13799, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31984635

RESUMO

BACKGROUND: The correlation of the growth hormone (GH) and insulin-like growth factor-1 (IGF-1) with non-alcoholic fatty liver disease (NAFLD) has been reported in epidemiological studies. However, the mechanisms of molecular and inter-organ systems that render these factors to influence on NAFLD have not been elucidated. In this study, we examined the induction of ghrelin which is the GH-releasing hormone and IGF-1, and involvement of autonomic neural circuits, in the pathogenesis of NAFLD. METHODS: The expression of gastric and hypothalamic ghrelin, neural activation in the brain, and serum IGF-1 were examined in NAFLD models of choline-deficient defined l-amino-acid diet-fed, melanocortin 4 receptor knockout mice, and partial hepatectomy mice with or without the blockades of autonomic nerves to test the contribution of neural circuits connecting the brain, liver, and stomach. KEY RESULTS: The fatty changes in the liver increased the expression of gastric ghrelin through the autonomic pathways which sends the neural signals to the arcuate nucleus in the hypothalamus through the afferent vagal nerve which reached the pituitary gland to release GH and then stimulate the IGF-1 release from the liver. In addition, high levels of ghrelin expression in the arcuate nucleus were correlated with NAFLD progression regardless of the circuits. CONCLUSIONS: Our study demonstrated that the fatty liver stimulates the autonomic nervous signal circuits which suppress the progression of the disease by activating the gastric ghrelin expression, the neural signal transduction in the brain, and the release of IGF-1 from the liver.


Assuntos
Sistema Nervoso Autônomo/metabolismo , Sistema Nervoso Autônomo/patologia , Grelina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Hipotálamo/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Bloqueio Nervoso , Estômago/inervação , Estômago/patologia , Nervo Vago/patologia
14.
Plant Cell Physiol ; 50(4): 838-54, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19233867

RESUMO

The plant circadian clock generates rhythms with a period close to 24 h, and it controls a wide range of physiological and developmental oscillations in habitats under natural light/dark cycles. Among clock-controlled developmental events, the best characterized is the photoperiodic control of flowering time in Arabidopsis thaliana. Recently, it was also reported that the clock regulates a daily and rhythmic elongation of hypocotyls. Here, we report that the promotion of hypocotyl elongation is in fact dependent on changes in photoperiods in such a way that an accelerated hypocotyl elongation occurs especially under short-day conditions. In this regard, we provide genetic evidence to show that the circadian clock regulates the photoperiodic (or seasonal) elongation of hypocotyls by modulating the expression profiles of the PIF4 and PIF5 genes encoding phytochrome-interacting bHLH (basic helix-loop-helix) factors, in such a manner that certain short-day conditions are necessary to enhance the expression of these genes during the night-time. In other words, long-day conditions are insufficient to open the clock-gate for triggering the expression of PIF4 and PIF5 during the night-time. Based on these and other results, the photoperiodic control of hypocotyl elongation is best explained by the accumulation of PIF4 and PIF5 during the night-time of short days, due to coincidence between the internal (circadian rhythm) and external (photoperiod) time cues. This mechanism is a mirror image of the photoperiod-dependent promotion of flowering in that plants should experience long-day conditions to initiate flowering promptly. Both of these clock-mediated coincidence mechanisms may coordinately confer ecological fitness to plants growing in natural habitats with varied photoperiods.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Ritmo Circadiano , Hipocótilo/crescimento & desenvolvimento , Fotoperíodo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , RNA de Plantas/genética
15.
Plant Cell Physiol ; 50(2): 290-303, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19098071

RESUMO

In Arabidopsis thaliana, a consistent multiloop clock model has been widely adopted in many recent publications. This tentative model consists of three interactive feedback loops, namely the core CCA1/LHY-TOC1/X loop, the morning CCA1/LHY-PRR9/PRR7 loop and the evening Y-TOC1 loop, in which the undefined Y gene might be GI. The model in its current form provides us with a basis on which to address a number of fundamental issues for a better understanding of the molecular mechanism by which the central oscillator generates circadian rhythms. We have been conducting a series of genetic studies through the establishment of a set of combinatorial mutants. We have already characterized a prr9 prr7 double loss-of-function mutant that has lost the morning loop, and a cca1 lhy toc1 triple mutant that lacks the core loop. Extension of this line of study required characterization of a gi toc1 double loss-of-function mutant, which is expected to have no evening loop, and a prr9 prr7 toc1 triple mutant, lacking both the morning and evening loops. Genetic analysis of both these lines is reported here. From the results, we have clarified the genetic linkages between GI and TOC1 and those between PRR9/PRR7 and TOC1 with reference to the circadian clock-associated phenotypes, including: (i) length of hypocotyls during early photomor-phogenesis; (ii) photoperiodic control of flowering time; and (iii) expression profiles of CCA1 and LHY under free-running conditions. These results indicate that GI is not sufficient to fulfill the Y role, but plays more complicated clock-associated roles and, interestingly, that no epistatic interaction between PRR9/PRR7 and TOC1 was observed. Furthermore, these clock-defective mutants could still generate robust, free-running rhythms at the level of transcription. Therefore, we speculate that an as yet undefined oscillator (or loop) continues to generate rhythms within the plants lacking GI/TOC1 or PRR9/PRR7/TOC1.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Relógios Biológicos/genética , Ritmo Circadiano/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Flores/genética , Flores/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Mutação , Fenótipo , Fotoperíodo , RNA de Plantas/metabolismo , Fatores de Transcrição
16.
Intern Med ; 58(23): 3393-3400, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31327836

RESUMO

Fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases that cause aneurysm, occlusion, and thromboses. These diseases are rarely seen in mesenteric arterial lesions; however, as they can be lethal if appropriate management is not provided, the accumulation of clinical information from cases is essential. We herein report the cases of a 57-year-old man diagnosed with FMD and a 63-year-old man diagnosed with SAM. We conclude that an early diagnosis with imaging modalities and clinical information followed by the appropriate treatment improves the prognosis of these arterial diseases.


Assuntos
Arteriopatias Oclusivas/complicações , Displasia Fibromuscular/complicações , Aneurisma/diagnóstico , Aneurisma/etiologia , Arteriopatias Oclusivas/diagnóstico , Artérias/patologia , Diagnóstico Precoce , Feminino , Displasia Fibromuscular/diagnóstico , Humanos , Masculino , Mesentério/irrigação sanguínea , Mesentério/patologia , Pessoa de Meia-Idade , Prognóstico , Doenças Raras/complicações , Doenças Raras/diagnóstico , Trombose/diagnóstico , Trombose/etiologia
17.
FEBS Open Bio ; 9(4): 643-652, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30984539

RESUMO

The rise in the incidence of nonalcoholic steatohepatitis (NASH) has necessitated the development of an effective prevention methodology. An antidiabetic drug, belonging to the group of sodium glucose cotransporter 2 (SGLT2) inhibitors, has been tested for its therapeutic effect on NASH; however, no studies to date have demonstrated the preventive effect of an SGLT2 inhibitor on the histological progression of steatosis and fibrosis in a sequential manner in animal models. In the present study, we examined the effect of the SGLT2 inhibitor, tofogliflozin (Tofo), on NASH liver tissue using medaka as an animal model, maintaining a feeding amount and drug concentration in all animal bodies. We generated a medaka NASH model by feeding d-rR/Tokyo medaka a high-fat diet and administered Tofo by dissolving the drug directly in the water of the feeding tank. Thereafter, the effects of Tofo on body weight (BW), liver weight, hepatotoxicity, fatty infiltration, and fibrotic changes in the liver were examined. We report here that SGLT2 is expressed in medaka fish and that Tofo inhibits the accumulation of fatty tissue and delays the progression of liver fibrosis in the medaka NASH model by inhibiting increases in blood sugar, serum lipids, and transaminase, irrespective of changes in BW. These results suggest that Tofo is effective for treating NASH and that the medaka model may be useful for developing new therapeutic drugs for this disease.


Assuntos
Compostos Benzidrílicos/farmacologia , Fígado Gorduroso/tratamento farmacológico , Proteínas de Peixes/metabolismo , Glucosídeos/farmacologia , Cirrose Hepática/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Transportador 2 de Glucose-Sódio/metabolismo , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Proteínas de Peixes/antagonistas & inibidores , Fígado/metabolismo , Oryzias
18.
FEBS Open Bio ; 9(12): 2016-2024, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31561285

RESUMO

The effect of sodium-glucose cotransporter 2 inhibitor (SGLT2I) on nonalcoholic steatohepatitis (NASH) has been reported, but there are few studies on its effect on NASH-related renal injury. In this study, we examined the effect of SGLT2I using a novel medaka fish model of NASH-related kidney disease, which was developed by feeding the d-rR/Tokyo strain a high-fat diet. SGLT2I was administered by dissolving it in water of the feeding tank. SGLT2I ameliorates macrophage accumulation and oxidative stress and maintained mitochondrial function in the kidney. The results demonstrate the effect of SGLT2I on NASH-related renal injury and the usefulness of this novel animal model for research into NASH-related complications.


Assuntos
Compostos Benzidrílicos/farmacologia , Glucosídeos/farmacologia , Proteínas de Transporte de Glutamato da Membrana Plasmática/metabolismo , Nefropatias/metabolismo , Animais , Diabetes Mellitus Tipo 2 , Dieta Hiperlipídica , Modelos Animais de Doenças , Glucose/metabolismo , Proteínas de Transporte de Glutamato da Membrana Plasmática/antagonistas & inibidores , Proteínas de Transporte de Glutamato da Membrana Plasmática/fisiologia , Hipoglicemiantes , Rim/patologia , Nefropatias/fisiopatologia , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/metabolismo , Oryzias/metabolismo , Sódio/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia
19.
Cancer Manag Res ; 11: 4437-4448, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31191006

RESUMO

Background: Sorafenib (SOR) is an anti-angiogenic chemotherapeutic that prolongs the survival rates of patients with hepatocellular carcinoma. However, SOR also damages normal vasculature and causes associated adverse events, including hand-foot syndrome and hypertension (HT). We previously reported in an animal study that vascular damage resulted in the narrowing of the normal vascular dimension area in medaka fish (Oryzias), and histidine (HIS), a major amino acid contained in dried bonito broth (DBB), prevented these changes. Therefore, in the study, we analyzed the effects of DBB and HIS on SOR-related vascular damages and associated adverse events in patients. Materials and methods: Three-dimensional (3D) vascular images of abdominal regions reconstituted from computed tomography were assessed to compare vascular diameter prior to and following SOR administration in groups receiving SOR monotherapy, DBB+SOR, and HIS+SOR. The clinical courses of hand-foot syndrome and HT and the toxicities of SOR in biochemical assays were monitored and compared between the groups. Correlations between hepatic function and SOR-related changes in the portal venous area dimension were also assessed. Results: SOR-related vascular damage revealed narrowing of the normal abdominal vasculature in the human body, which was monitored using 3D images. The damage was ameliorated by DBB and HIS, however, HIS had a more marked effect, particularly on the renal arteries and portal vein (PV). Maintenance of blood flow contributed to the maintenance of total cholesterol, prothrombin time, albumin (ALB), and renal functions. Changes in the 3D vascular area dimension of the PV and level of serum ALB were significantly correlated. The occurrences of the clinical symptoms of hand-foot syndrome and HT were lower in the DBB- and HIS-treated groups. Conclusion: Our results clearly demonstrate that DBB and HIS prevented SOR-related abdominal vascular damage and effectively maintained hepatic function, and prevented clinical symptoms and toxicity. Trial registration: This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000025937 and UMIN000026898).

20.
Plant Cell Physiol ; 49(2): 201-13, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18178585

RESUMO

In Arabidopsis thaliana, many circadian clock-associated genes have been identified. Among them, the evening-expressed TOC1 (TIMING OF CAB EXPRESSION 1) gene plays a role by forming a transcriptional feedback core loop together with the morning-expressed CCA1 (CIRCADIAN CLOCK-ASSOCIATED 1) gene and its homologous LHY (LATE ELONGATED HYPOCOTYL) gene. TOC1 encodes a member of the PSEUDO-RESPONSE REGULATOR (PRR) family, including PRR9, PRR7, PRR5, PRR3,and PRR1/TOC1. The PRR genes other than TOC1 (or PRR1) also appear to be crucial for certain circadian-associated events. To clarify missing genetic linkages amongst these PRR genes, here we constructed a toc1 prr5 double knockdown mutant. In free-running circadian rhythms, the resulting toc1-2 prr5-11 mutant plants showed an extremely short period and reduced amplitude phenotype, which was more severe than that of the toc1-2 single mutant plant, suggesting a non-linear genetic interaction between TOC1 and PRR5. Surprisingly, the hallmark early flowering phenotype of toc1-2 in the short-day conditions had been converted to a markedly late flowering phenotype in the long-day conditions, when combined with the prr5-11 allele, which itself showed a subtle flowering phenotype. This unexpected genetic result (i.e. phenotypic sign conversion) suggested that the TOC1 and PRR5 genes are coordinately implicated in a non-linear and closed genetic circuitry. In the toc1-2 prr5-11 double mutant, the diurnal expression profile of CDF1 (CYCLING DOF FACTOR 1) was markedly de-repressed in the evening in the long-day conditions. These and other results of this study led us to propose the novel view that TOC1 might play bipartite roles in the control of flowering time within a closed circuitry; the one is a GI (GIGANTEA)-dependent negative role through CCA1/LHY, and the other is a CDF1-dependent positive role through cooperating closely with PRR5.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Relógios Biológicos/genética , Ritmo Circadiano/fisiologia , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Flores/genética , Flores/metabolismo , Mutação , Fatores de Transcrição/genética
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