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1.
Cancer Sci ; 115(6): 1936-1947, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38590281

RESUMO

The immunoglobulin superfamily (IgSF) is one of the largest families of cell-surface molecules involved in various cell-cell interactions, including cancer-stromal interactions. In this study, we undertook a comprehensive RT-PCR-based screening for IgSF molecules that promote experimental lung metastasis in mice. By comparing the expression of 325 genes encoding cell-surface IgSF molecules between mouse melanoma B16 cells and its highly metastatic subline, B16F10 cells, we found that expression of the immunoglobulin superfamily member 3 gene (Igsf3) was significantly enhanced in B16F10 cells than in B16 cells. Knockdown of Igsf3 in B16F10 cells significantly reduced lung metastasis following intravenous injection into C57BL/6 mice. IGSF3 promoted adhesion of B16F10 cells to vascular endothelial cells and functioned as a homophilic cell adhesion molecule between B16F10 cells and vascular endothelial cells. Notably, the knockdown of IGSF3 in either B16F10 cells or vascular endothelial cells suppressed the transendothelial migration of B16F10 cells. Moreover, IGSF3 knockdown suppressed the extravasation of B16F10 cells into the lungs after intravenous injection. These results suggest that IGSF3 promotes the metastatic potential of B16F10 cells in the lungs by facilitating their adhesion to vascular endothelial cells.


Assuntos
Adesão Celular , Endotélio Vascular , Neoplasias Pulmonares , Melanoma Experimental , Camundongos Endogâmicos C57BL , Animais , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Camundongos , Adesão Celular/genética , Melanoma Experimental/patologia , Melanoma Experimental/metabolismo , Melanoma Experimental/genética , Linhagem Celular Tumoral , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Imunoglobulinas/metabolismo , Imunoglobulinas/genética , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular/genética , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Técnicas de Silenciamento de Genes , Humanos
2.
Biol Pharm Bull ; 47(1): 23-27, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38171776

RESUMO

Mammalian type 2 carnitine parmitoyltransferase (EC 2.3.1.21), abbreviated as CPT2, is an enzyme involved in the translocation of fatty acid into the mitochondrial matrix space, and catalyzes the reaction acylcarnitine + CoA = acyl-CoA + carnitine. When rat CPT2 was expressed in Escherichia coli, its behavior was dependent on the presence or absence of i) its mitochondrial localization sequence and ii) a short amino acid sequence thought to anchor it to the mitochondrial inner membrane: CPT2 containing both sequences behaved as a hydrophobic protein, while recombinant CPT2 lacking both regions behaved as a water soluble protein; if only one region was present, the resultant proteins were observed in both fractions. Because relatively few protein species could be obtained from bacterial lysates as insoluble pellets under the experimental conditions used, selective enrichment of recombinant CPT2 protein containing both hydrophobic sequences was easily achieved. Furthermore, when CPT2 enriched in insoluble fraction was resuspended in an appropriate medium, it showed catalytic activity typical of CPT2: it was completely suppressed by the CPT2 inhibitor, ST1326, but not by the CPT1 inhibitor, malonyl-CoA. Therefore, we conclude that the bacterial expression system is an effective tool for characterization studies of mammalian CPT2.


Assuntos
Carnitina O-Palmitoiltransferase , Mitocôndrias , Ratos , Animais , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/química , Mitocôndrias/metabolismo , Malonil Coenzima A/metabolismo , Malonil Coenzima A/farmacologia , Ácidos Graxos/metabolismo , Proteínas Recombinantes/genética , Carnitina/metabolismo , Mamíferos/metabolismo
3.
J Bacteriol ; 205(1): e0038922, 2023 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-36475831

RESUMO

Bacteroides species can use fumarate and oxygen as terminal electron acceptors during cellular respiration. In the human gut, oxygen diffuses from intestinal epithelial cells supplying "nanaerobic" oxygen levels. Many components of the anaerobic respiratory pathway have been determined, but such analyses have not been performed for nanaerobic respiration. Here, we present genetic, biochemical, enzymatic, and mass spectrometry analyses to elucidate the nanaerobic respiratory pathway in Bacteroides fragilis. Under anaerobic conditions, the transfer of electrons from NADH to the quinone pool has been shown to be contributed by two enzymes, NQR and NDH2. We find that the activity contributed by each under nanaerobic conditions is 77 and 23%, respectively, similar to the activity levels under anaerobic conditions. Using mass spectrometry, we show that the quinone pool also does not differ under these two conditions and consists of a mixture of menaquinone-8 to menaquinone-11, with menaquinone-10 predominant under both conditions. Analysis of fumarate reductase showed that it is synthesized and active under anaerobic and nanaerobic conditions. Previous RNA sequencing data and new transcription reporter assays show that expression of the cytochrome bd oxidase gene does not change under these conditions. Under nanaerobic conditions, we find both increased CydA protein and increased cytochrome bd activity. Reduced-minus-oxidized spectra of membranes showed the presence of heme d when the bacteria were grown in the presence of protoporphyrin IX and iron under both anaerobic and nanaerobic conditions, suggesting that the active oxidase can be assembled with or without oxygen. IMPORTANCE By performing a comprehensive analysis of nanaerobic respiration in Bacteroides fragilis, we show that this organism maintains capabilities for anaerobic respiration on fumarate and nanaerobic respiration on oxygen simultaneously. The contribution of the two NADH:quinone oxidoreductases and the composition of the quinone pool are the same under both conditions. Fumarate reductase and cytochrome bd are both present, and which of these terminal enzymes is active in electron transfer depends on the availability of the final electron acceptor: fumarate or oxygen. The synthesis of cytochrome bd and fumarate reductase under both conditions serves as an adaptation to an environment with low oxygen concentrations so that the bacteria can maximize energy conservation during fluctuating environmental conditions or occupation of different spatial niches.


Assuntos
Bacteroides fragilis , Succinato Desidrogenase , Humanos , Bacteroides fragilis/genética , Bacteroides fragilis/metabolismo , Anaerobiose , Succinato Desidrogenase/metabolismo , Vitamina K 2 , NAD/metabolismo , Transporte de Elétrons , Citocromos/metabolismo , Quinonas/metabolismo , Respiração , Oxigênio/metabolismo , Fumaratos/metabolismo
4.
J Neurochem ; 165(3): 303-317, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36547371

RESUMO

Cells possess intrinsic features that are inheritable via epigenetic regulation, such as DNA methylation and histone modification. These inheritable features maintain a unique gene expression pattern, underlying cellular memory. Because of the degradation or displacement of mitotic chromosomes, most transcription factors do not contribute to cellular memory. However, accumulating in vitro evidence indicates that some transcription factors can be retained in mitotic chromosomes called as bookmarking. Such transcription factors may contribute to a novel third mechanism of cellular memory. Since most findings of transcription factor bookmarking have been reported in vitro, little is currently known in vivo. In the neural tube of mouse embryos, we discovered that OLIG2, a basic helix loop helix (bHLH) transcription factor that regulates proliferation of neural progenitors and the cell fate of motoneurons and oligodendrocytes, binds to chromatin through every cell cycle including M-phase. OLIG2 chromosomal localization coincides with mitotic cell features such as the phosphorylation of histone H3, KI67, and nuclear membrane breakdown. Chromosomal localization of OLIG2 is regulated by an N-terminus triple serine motif. Photobleaching analysis revealed slow OLIG2 mobility, suggesting a high affinity of OLIG2 to DNA. In Olig2 N-terminal deletion mutant mice, motoneurons and oligodendrocyte progenitor numbers are reduced in the neural tube, suggesting that the bookmarking regulatory domain is important for OLIG2 function. We conclude that OLIG2 is a de novo in vivo bookmarking transcription factor. Our results demonstrate the presence of in vivo bookmarking in a living organism and illustrate a novel function of transcription factors.


Assuntos
Epigênese Genética , Fatores de Transcrição , Camundongos , Animais , Fatores de Transcrição/genética , Tubo Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fator de Transcrição 2 de Oligodendrócitos/genética , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular/genética , Oligodendroglia/metabolismo
5.
Plant Physiol ; 189(1): 419-432, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35348770

RESUMO

Chlorophyll (Chl) serves a number of essential functions, capturing and converting light energy as a component of photosystem supercomplexes. Chl degradation during leaf senescence is also required for adequate degeneration of chloroplasts and salvaging of nutrients from senescent leaves. In this study, we performed genetic analysis to determine the functions of BALANCE of CHLOROPHYLL METABOLISM1 (BCM1) and BCM2, which control Chl levels by regulating synthesis and degradation, and STAY-GREEN (SGR)1 (also known as NON-YELLOWING1 [NYE1]) and SGR2, which encode Mg-dechelatase and catalyze Chl a degradation in Arabidopsis (Arabidopsis thaliana). Analysis of bcm1 bcm2 revealed that both BCM1 and BCM2 are involved in the regulation of Chl levels in presenescent leaves and Chl degradation in senescing leaves. Analysis of bcm1 bcm2 nye1 nye2 suggested that BCMs repress Chl-degrading activity in both presenescent and senescing leaves by regulating SGR activity. Furthermore, transactivation analysis and chromatin immunoprecipitation (ChIP) assay revealed that GOLDEN2-LIKE1 (GLK1), a central transcription factor regulating the expression of genes encoding photosystem-related proteins, such as light-harvesting Chl a/b-binding proteins (LHCPs), directly regulates the transcription of BCM1. LHCPs are stabilized by Chl binding, suggesting that GLKs control the amount of LHCP through transcriptional and post-translational regulation via BCM-mediated Chl-level regulation. Meanwhile, we generated a mutant of the BCM ortholog in lettuce (Lactuca sativa) by genome editing and found that it showed an early yellowing phenotype, but only a slight reduction in Chl in presenescent leaves. Thus, this study revealed a conserved but slightly diversified regulation of Chl and LHCP levels via the GLK-BCM pathway in eudicots.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Complexos de Proteínas Captadores de Luz/genética , Complexos de Proteínas Captadores de Luz/metabolismo , Folhas de Planta/metabolismo , Fatores de Transcrição/metabolismo
6.
Microbiol Immunol ; 67(3): 120-128, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36480238

RESUMO

Two messenger RNA (mRNA) vaccines of BNT162b2 and mRNA-1273 were licensed. The most common adverse event is regional pain at the injection site in 80%. As systemic reactions, fatigue and headache were noted in 40%-60% and febrile illness in 10%-40% of the recipients. To investigate the mechanism of adverse events, cytokine profiles were investigated in mice. Muscle tissue and serum samples were obtained on days 0, 1, 3, 5, and 7, and at 2 and 4 weeks after the first dose. The second dose was given 4 weeks after the first dose and samples were obtained. After inoculation with 0.1 mL of mRNA-1273, IFN-γ and IL-2 were detected in muscle tissues and serum samples on day 1 of the second doses, and similar profiles were observed for IL-4, IL-5, and IL-12 production. mRNA-1273 induced higher levels of Th1 and Th2 cytokines. TNF-α was induced in muscle tissues on day 1 of the first dose and enhanced on day 1 of the second dose after inoculation with BNT162b2 and mRNA-1273. IL-6 was also detected in muscle tissue on day 1 of the first dose, but it decreased after day 3, and enhanced production was demonstrated on day 1 of the second dose. Granulocyte colony-stimulating factor in muscle tissues showed a similar profile. The induction of inflammatory cytokines in the mouse model is related to the cause of adverse events in humans, with a higher incidence of adverse events after the second dose.


Assuntos
Vacina de mRNA-1273 contra 2019-nCoV , Vacina BNT162 , Humanos , Animais , Camundongos , Vacinas de mRNA , RNA Mensageiro/genética , Citocinas
7.
Proc Natl Acad Sci U S A ; 117(39): 24484-24493, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32938803

RESUMO

Mechanistic studies of anaerobic gut bacteria have been hindered by the lack of a fluorescent protein system to track and visualize proteins and dynamic cellular processes in actively growing bacteria. Although underappreciated, many gut "anaerobes" are able to respire using oxygen as the terminal electron acceptor. The oxygen continually released from gut epithelial cells creates an oxygen gradient from the mucus layer to the anaerobic lumen [L. Albenberg et al., Gastroenterology 147, 1055-1063.e8 (2014)], with oxygen available to bacteria growing at the mucus layer. Here, we show that Bacteroides species are metabolically and energetically robust and do not mount stress responses in the presence of 0.10 to 0.14% oxygen, defined as nanaerobic conditions [A. D. Baughn, M. H. Malamy, Nature 427, 441-444 (2004)]. Taking advantage of this metabolic capability, we show that nanaerobic growth provides sufficient oxygen for the maturation of oxygen-requiring fluorescent proteins in Bacteroides species. Type strains of four different Bacteroides species show bright GFP fluorescence when grown nanaerobically versus anaerobically. We compared four different red fluorescent proteins and found that mKate2 yields the highest red fluorescence intensity in our assay. We show that GFP-tagged proteins can be localized in nanaerobically growing bacteria. In addition, we used time-lapse fluorescence microscopy to image dynamic type VI secretion system processes in metabolically active Bacteroides fragilis The ability to visualize fluorescently labeled Bacteroides and fluorescently linked proteins in actively growing nanaerobic gut symbionts ushers in an age of imaging analyses not previously possible in these bacteria.


Assuntos
Bacteroides/metabolismo , Microbioma Gastrointestinal , Aerobiose , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteroides/classificação , Bacteroides/genética , Bacteroides/crescimento & desenvolvimento , Humanos , Oxigênio/metabolismo , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo
8.
Cancer Sci ; 113(5): 1669-1678, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35213073

RESUMO

The initial step of organ infiltration of malignant cells is the interaction with host vascular endothelial cells, which is often mediated by specific combinations of cell adhesion molecules. Cell adhesion molecule 1 (CADM1) is overexpressed in adult T-cell leukemia/lymphoma (ATL) and provides a cell-surface diagnostic marker. CADM1 promotes the adhesion of ATL cells to vascular endothelial cells and multiple organ infiltration in mice. However, its binding partner on host cells has not yet been identified. In this study, we show that CADM1 promotes transendothelial migration of ATL cells in addition to the adhesion to vascular endothelial cells. Moreover, CADM1 enhances liver infiltration of mouse T-cell lymphoma cells, EL4, after tail vein injection, whereas a CADM1 mutant lacking adhesive activity did not. Among the known CADM1-binding proteins expressed in primary endothelial cells, only CADM1 and CADM4 could induce morphological extension of ATL cells when plated onto glass coated with these proteins. Furthermore, CADM1-mediated liver infiltration of EL4 cells was canceled in conventional and vascular endothelium-specific Cadm1 knockout mice, whereas it was not canceled in Cadm4 knockout mice. These results suggest that CADM1 on host vascular endothelial cells is required for organ infiltration of ATL and other T-cell lymphomas expressing CADM1.


Assuntos
Molécula 1 de Adesão Celular/metabolismo , Endotélio Vascular , Linfoma de Células T , Animais , Adesão Celular , Molécula 1 de Adesão Celular/genética , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Humanos , Imunoglobulinas/química , Imunoglobulinas/genética , Linfoma de Células T/genética , Camundongos
9.
Int Immunol ; 33(3): 171-182, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33038259

RESUMO

T-cell development depends on the thymic microenvironment, in which endothelial cells (ECs) play a vital role. Interestingly, vascular permeability of the thymic cortex is lower than in other organs, suggesting the existence of a blood-thymus barrier (BTB). On the other hand, blood-borne molecules and dendritic cells bearing self-antigens are accessible to the medulla, facilitating central tolerance induction, and continuous T-precursor immigration and mature thymocyte egress occur through the vessels at the cortico-medullary junction (CMJ). We found that claudin-5 (Cld5), a membrane protein of tight junctions, was expressed in essentially all ECs of the cortical vasculatures, whereas approximately half of the ECs of the medulla and CMJ lacked Cld5 expression. An intravenously (i.v.) injected biotin tracer hardly penetrated cortical Cld5+ vessels, but it leaked into the medullary parenchyma through Cld5- vessels. Cld5 expression in an EC cell line caused a remarkable increase in trans-endothelial resistance in vitro, and the biotin tracer leaked from the cortical vasculatures in Cldn5-/- mice. Furthermore, i.v.-injected sphingosine-1 phosphate distributed selectively into the medulla through the Cld5- vessels, probably ensuring the egress of CD3high mature thymocytes from Cld5- vessels at the CMJ. These results suggest that distinct Cld5 expression profiles in the cortex and medulla may control the BTB and the T-cell gateway to blood circulation, respectively.


Assuntos
Permeabilidade Capilar/fisiologia , Claudina-5/metabolismo , Linfócitos T/metabolismo , Timo/metabolismo , Junções Íntimas/fisiologia , Animais , Diferenciação Celular/imunologia , Linhagem Celular , Claudina-5/biossíntese , Células Endoteliais/metabolismo , Lisofosfolipídeos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Linfócitos T/citologia , Timócitos/metabolismo
10.
J Immunol ; 205(8): 2008-2015, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32907997

RESUMO

Immune complexes (ICs) in blood are efficiently removed mainly by liver reticuloendothelial systems consisting of sinusoidal endothelial cells and Kupffer cells expressing FcγR. The bone marrow (BM) also has sinusoidal vasculatures, and sinusoidal BM endothelial cells (BMECs) bear unique function, including hematopoietic niches and traffic regulation of hematopoietic cells. In this study, we found that sinusoidal BMECs express FcγRIIb2, which is markedly increased in anemic conditions or by the administration of erythropoietin (Epo) in healthy mice. BMECs expressed Epo receptor (EpoR), and the Epo-induced increase in FcγRIIb2 expression was abolished in Epor-/- ::HG1-Epor transgenic mice, which lack EpoR in BMECs except for BM erythroblasts, suggesting the effect was directly mediated via EpoR on BMECs. Further, although BMECs hardly captured i.v.-injected soluble ICs in healthy mice, Epo administration induced a remarkable increase in the uptake of ICs in a FcγRIIb-dependent manner. Enhancement of the IC incorporation capacity by Epo was also observed in cultured BMECs in vitro, suggesting the direct effect of Epo on BMECs. Moreover, we found that i.v.-injected ICs in Epo-treated mice were more rapidly removed from the circulation than in PBS-treated mice. These results reveal a novel function of BMECs to efficiently remove circulating blood-borne ICs in an FcγRIIb2-mediated manner.


Assuntos
Complexo Antígeno-Anticorpo/imunologia , Células da Medula Óssea/imunologia , Células Endoteliais/imunologia , Eritropoetina/imunologia , Receptores de IgG/imunologia , Animais , Complexo Antígeno-Anticorpo/sangue , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Eritropoetina/sangue , Eritropoetina/genética , Camundongos , Camundongos Knockout , Receptores de IgG/sangue , Receptores de IgG/genética
11.
Clin Exp Nephrol ; 26(5): 466-475, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35048329

RESUMO

BACKGROUND: A Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown a one-to-one male-to-female mortality ratio, notwithstanding the statistically longer life expectancy of women in the general population. This finding contrasts with the recent report that Japanese women on dialysis treatment have a more favorable longevity. Accordingly, we further investigated the clinical procedures and outcomes to clarify the sex differences in Japanese patients undergoing dialysis treatment. METHODS: Subjects were incident dialysis patients who participated in a multicenter prospective cohort study from October 2011 to September 2013. The all-cause mortality was analyzed by a Cox proportional hazard regression model and studied separately in women and men with or without cardiovascular disease (CVD) at baseline. RESULTS: Overall, 492 (32.3%) of the 1520 test subjects were women. All-cause mortality was higher in men (28.6%) than in women (19.9%, p < 0.001). Female sex (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.54-0.90) and history of CVD (HR: 1.51, 95% CI: 1.18-1.95) were independent predictors of all-cause mortality. In patients without CVD, female gender was strong independent contributor (HR = 0.46, 95% CI: 0.30-0.70, p < 0.001). In contrast, patients with CVD showed no difference in survival between the sexes (HR: 0.92, 95% CI: 0.67-1.24, p = 0.597). CONCLUSION: Our study demonstrated that women undergoing chronic dialysis therapy had a lower mortality risk than men. However, complication with CVD canceled out the survival advantage in Japanese women on chronic dialysis. We should reevaluate the risk of women with CVD undergoing dialysis and apply the optimal care for CVD.


Assuntos
Doenças Cardiovasculares , Caracteres Sexuais , Feminino , Humanos , Japão/epidemiologia , Masculino , Estudos Prospectivos , Diálise Renal/efeitos adversos , Fatores de Risco
12.
J Fish Biol ; 100(1): 82-91, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34622452

RESUMO

In this study, the authors report the first record of egg masses deposited in solitary tunicates by the snubnose sculpin, Orthonopias triacis, from the Northeastern Pacific. Four egg masses were discovered in the tunicate Ascidia ceratodes that were genetically determined to be O. triacis. Female O. triacis had long ovipositors that allow deposition of their eggs inside the atrium of the tunicates. A comparison of host-tunicate size with ovipositor length of sculpins from the Northwestern Pacific, including the genera Furcina and Pseudoblennius, revealed that O. triacis had shorter ovipositors and spawned in the atrium of smaller species of tunicates. Ancestral state reconstruction of egg deposition in solitary tunicates using 1.86Mbp RNAseq data of 20 sculpin species from Northeastern and Northwestern Pacific revealed that this unusual spawning behaviour may have evolved convergently in different species occurring in the Northeastern vs. the Northwestern Pacific.


Assuntos
Perciformes , Urocordados , Animais , Feminino
13.
J Biol Chem ; 295(36): 12739-12754, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690607

RESUMO

The Na+-pumping NADH-ubiquinone (UQ) oxidoreductase (Na+-NQR) is present in the respiratory chain of many pathogenic bacteria and is thought to be a promising antibiotic target. Whereas many details of Na+-NQR structure and function are known, the mechanisms of action of potent inhibitors is not well-understood; elucidating the mechanisms would not only advance drug design strategies but might also provide insights on a terminal electron transfer from riboflavin to UQ. To this end, we performed photoaffinity labeling experiments using photoreactive derivatives of two known inhibitors, aurachin and korormicin, on isolated Vibrio cholerae Na+-NQR. The inhibitors labeled the cytoplasmic surface domain of the NqrB subunit including a protruding N-terminal stretch, which may be critical to regulate the UQ reaction in the adjacent NqrA subunit. The labeling was blocked by short-chain UQs such as ubiquinone-2. The photolabile group (2-aryl-5-carboxytetrazole (ACT)) of these inhibitors reacts with nucleophilic amino acids, so we tested mutations of nucleophilic residues in the labeled region of NqrB, such as Asp49 and Asp52 (to Ala), and observed moderate decreases in labeling yields, suggesting that these residues are involved in the interaction with ACT. We conclude that the inhibitors interfere with the UQ reaction in two ways: the first is blocking structural rearrangements at the cytoplasmic interface between NqrA and NqrB, and the second is the direct obstruction of UQ binding at this interfacial area. Unusual competitive behavior between the photoreactive inhibitors and various competitors corroborates our previous proposition that there may be two inhibitor binding sites in Na+-NQR.


Assuntos
Proteínas de Bactérias/metabolismo , NADH NADPH Oxirredutases/metabolismo , Ubiquinona/metabolismo , Vibrio cholerae/metabolismo , Proteínas de Bactérias/genética , NADH NADPH Oxirredutases/genética , Ubiquinona/genética , Vibrio cholerae/genética
14.
Plant Mol Biol ; 105(4-5): 463-482, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33474657

RESUMO

KEY MESSAGE: SCL3 inhibits transcriptional activity of IDD-DELLA complex by acting as a co-repressor and repression activity is enhanced in the presence of GAF1 in a TOPLESS-independent manner. GRAS [GIBBERELLIN-INSENSITIVE (GAI), REPRESSOR OF ga1-3 (RGA) and SCARECROW (SCR)] proteins are a family of plant-specific transcriptional regulators that play diverse roles in development and signaling. GRAS family DELLA proteins act as growth repressors by inhibiting gibberellin (GA) signaling in response to developmental and environmental cues. DELLAs also act as co-activators of transcription factor GAI-ASSOCIATED FACTOR1 (GAF1)/INDETERMINATE DOMAIN2 (IDD2), the GAF1-DELLA complex activating transcription of GAF1 target genes. GAF1 also interacts with TOPLESS (TPL), a transcriptional co-repressor, in the absence of DELLA, the GAF1-TPL complex repressing transcription of the target genes. SCARECROW-LIKE3 (SCL3), another member of the GRAS family, is thought to inhibit transcriptional activity of the IDD-DELLA complex through competitive interaction with IDD. Here, we also revealed that SCL3 inhibits transcriptional activation by the GAF1-DELLA complex via repression activity rather than via competitive inhibition of the GAF1-DELLA interaction. Moreover, the repression activity of SCL3 was enhanced by GAF1 in a TPL-independent manner. While the GRAS domain of DELLA has transcriptional activation activity, that of SCL3 has repression activity. SCL3 also inhibited transcriptional activity of GAF1-RGA fusion proteins. Results from the co-immunoprecipitation assays and the yeast three-hybrid assay suggested the possibility that SCL3 forms a ternary complex with GAF1 and DELLA. These findings provide important information on DELLA-regulated GA signaling and new insight into the transcriptional repression mechanism.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas Correpressoras/genética , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Ribonuclease P/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas Correpressoras/metabolismo , Immunoblotting , Ligação Proteica , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonuclease P/metabolismo , Transdução de Sinais/genética , Técnicas do Sistema de Duplo-Híbrido
15.
Cancer Sci ; 112(1): 444-453, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32860329

RESUMO

Copy number variation (CNV) is a polymorphism in the human genome involving DNA fragments larger than 1 kb. Copy number variation sites provide hotspots of somatic alterations in cancers. Herein, we examined somatic alterations at sites of CNV in DNA from 20 invasive breast cancers using a Comparative Genomic Hybridization array specifically designed to detect the genome-wide CNV status of approximately 412 000 sites. Somatic copy number alterations (CNAs) were detected in 39.9% of the CNV probes examined. The most frequently altered regions were gains of 1q21-22 (90%), 8q21-24 (85%), 1q44 (85%), and 3q11 (85%) or losses of 16q22-24 (80%). Gene ontology analyses of genes within the CNA fragments revealed that cascades related to transcription and RNA metabolism correlated significantly with human epidermal growth factor receptor 2 positivity and menopausal status. Thirteen of 20 tumors showed CNAs in more than 35% of sites examined and a high prevalence of CNAs correlated significantly with estrogen receptor (ER) negativity, higher nuclear grade (NG), and higher Ki-67 labeling index. Finally, when CNA fragments were categorized according to their size, CNAs smaller than 10 kb correlated significantly with ER positivity and lower NG, whereas CNAs exceeding 10 Mb correlated with higher NG, ER negativity, and a higher Ki-67 labeling index. Most of these findings were confirmed or supported by quantitative PCR of representative DNA fragments in 72 additional breast cancers. These results suggest that most CNAs are caused by gain or loss of large chromosomal fragments and correlate with NG and several malignant features, whereas solitary CNAs of less than 10 kb could be involved in ER-positive breast carcinogenesis.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Variações do Número de Cópias de DNA/genética , Adulto , Idoso , Hibridização Genômica Comparativa/métodos , Feminino , História do Século XVII , Humanos
16.
Biochem Biophys Res Commun ; 571: 201-209, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34332425

RESUMO

Cell signaling and the following gene regulation are tightly regulated to keep homeostasis. NF-κB is a famous key transcription factor for inflammatory cell regulations that obtain a closed feedback loop with IκB. Similarly, we show here, NFAT is also tightly regulated via its downstream target, down syndrome critical region (DSCR)-1. In primary cultured endothelium, either shear stress or VEGF treatment revealed quick NFAT1 nuclear localization following the DSCR-1 transactivation, which in turn induced NFAT1 cytoplasm sequestration. Interestingly, both NFAT and DSCR-1 can be competitive substrates for calcineurin phosphatase and DSCR-1 is known to unstable protein, which caused NFAT1-nucleocytoplasmic damped oscillation via sustained shear stress or VEGF stimulation in endothelial cell (EC)s. To understand the molecular mechanism underlying the NFAT1 oscillation, we built a mathematical model of spatiotemporal regulation of NFAT1 combined with calcineurin and DSCR-1. Theoretically, manipulation of DSCR-1 expression in simulation predicted that DSCR-1 reduction would cause nuclear retention of dephosphorylated NFAT1 and disappearance of NFAT1 oscillation. To confirm this in ECs, DSCR-1 knockdown analysis was performed. DSCR-1 reduction indeed increased dephosphorylated NFAT1 in both the nucleus and cytoplasm, which eventually led to nuclear retention of NFAT1. Taken together, these studies suggest that DSCR-1 is a responsible critical factor for NFAT1 nucleocytoplasmic oscillation in shear stress or VEGF treated ECs. Our mathematical model successfully reproduced the experimental observations of NFAT1 dynamics. Combined mathematical and experimental approaches would provide a quantitative understanding way for the spatiotemporal NFAT1 feedback system.


Assuntos
Calcineurina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células Endoteliais/metabolismo , Proteínas Musculares/metabolismo , Fatores de Transcrição NFATC/metabolismo , Transporte Ativo do Núcleo Celular , Linhagem Celular , Humanos , Transdução de Sinais
17.
Biochem Biophys Res Commun ; 534: 172-178, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33298314

RESUMO

Cell adhesion molecule 1 (CADM1), which mediates intercellular adhesion between epithelial cells, is shown to be highly expressed in small-cell lung cancer (SCLC) and to enhance tumorigenicity of SCLC cells in nude mice. Here, we investigated the molecular mechanism underlying the oncogenic role of CADM1 in SCLC. CADM1 promoted colony formation of SCLC cells in soft agar. Analysis of deletion and point mutants of the conserved protein-binding motifs in CADM1 revealed that the 4.1 protein-binding motif in the cytoplasmic domain is responsible for the promotion of colony formation. Among the actin-binding 4.1 proteins, 4.1R was the only protein whose localization to the plasma membrane is dependent on CADM1 expression in SCLC cells. Knockdown of 4.1R suppressed the colony formation enhanced by CADM1, suggesting that 4.1R is required for the oncogenic role of CADM1 in SCLC. In primary SCLC, CADM1 expression was correlated with membranous localization of 4.1R, as was observed in a SCLC cell line. Moreover, membranous co-localization of CADM1 and 4.1R was associated with more advanced tumor stage. These results suggest that the formation of CADM1-4.1R complex would promote malignant features of SCLC.


Assuntos
Molécula 1 de Adesão Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Membrana/metabolismo , Carcinoma de Pequenas Células do Pulmão/metabolismo , Animais , Molécula 1 de Adesão Celular/genética , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Feminino , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação , Carcinoma de Pequenas Células do Pulmão/patologia
18.
Shokuhin Eiseigaku Zasshi ; 62(4): 129-132, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34470942

RESUMO

The sensitivity of the 3M TM Molecular Detection Assay 2-STEC Gene Screen (stx) assay (3M MDA2 STEC assay) was evaluated for verotoxin (VT) gene screening from food materials. The pure culture and foods such as sliced beef, tandoori paste, cucumber, etc. were used for this study. The sensitivity was obtained as 3 to 4 log CFU/mL in enrichment broth (BPW and mEC), which was cultured with food matrices. These results showed this detection kit was suitable the notification of standard methods from Ministry of health, which requires 4 log CFU/mL as detection limit in enrichment broth. This assay was useful as a rapid and simple screening method for VT gene from foods.


Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Toxina Shiga , Escherichia coli Shiga Toxigênica , Animais , Bovinos , Escherichia , Escherichia coli Shiga Toxigênica/genética
19.
Cancer Sci ; 111(6): 2183-2195, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32237253

RESUMO

Molecular targeted therapies against EGFR and ALK have improved the quality of life of lung adenocarcinoma patients. However, targetable driver mutations are mainly found in thyroid transcription factor-1 (TTF-1)/NK2 homeobox 1 (NKX2-1)-positive terminal respiratory unit (TRU) types and rarely in non-TRU types. To elucidate the molecular characteristics of the major subtypes of non-TRU-type adenocarcinomas, we analyzed 19 lung adenocarcinoma cell lines (11 TRU types and 8 non-TRU types). A characteristic of non-TRU-type cell lines was the strong expression of TFF-1 (trefoil factor-1), a gastric mucosal protective factor. An immunohistochemical analysis of 238 primary lung adenocarcinomas resected at Jichi Medical University Hospital revealed that TFF-1 was positive in 31 cases (13%). Expression of TFF-1 was frequently detected in invasive mucinous (14/15, 93%), enteric (2/2, 100%), and colloid (1/1, 100%) adenocarcinomas, less frequent in acinar (5/24, 21%), papillary (7/120, 6%), and solid (2/43, 5%) adenocarcinomas, and negative in micropapillary (0/1, 0%), lepidic (0/23, 0%), and microinvasive adenocarcinomas or adenocarcinoma in situ (0/9, 0%). Expression of TFF-1 correlated with the expression of HNF4-α and MUC5AC (P < .0001, P < .0001, respectively) and inversely correlated with that of TTF-1/NKX2-1 (P < .0001). These results indicate that TFF-1 is characteristically expressed in non-TRU-type adenocarcinomas with gastrointestinal features. The TFF-1-positive cases harbored KRAS mutations at a high frequency, but no EGFR or ALK mutations. Expression of TFF-1 correlated with tumor spread through air spaces, and a poor prognosis in advanced stages. Moreover, the knockdown of TFF-1 inhibited cell proliferation and soft-agar colony formation and induced apoptosis in a TFF-1-high and KRAS-mutated lung adenocarcinoma cell line. These results indicate that TFF-1 is not only a biomarker, but also a potential molecular target for non-TRU-type lung adenocarcinomas.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Neoplasias Pulmonares/metabolismo , Fator Nuclear 1 de Tireoide/metabolismo , Fator Trefoil-1/metabolismo , Adenocarcinoma de Pulmão/classificação , Adenocarcinoma de Pulmão/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/classificação , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade
20.
Chem Pharm Bull (Tokyo) ; 68(8): 773-778, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32741919

RESUMO

Lower urinary tract symptoms (LUTS) induced by anticholinergic drug action impair the QOL of patients and are associated with a poor prognosis. Therefore, it is expedient to develop methods of predicting the anticholinergic side effects of drugs, which we aimed to achieve in this study using a quantitative structure-activity relationship (QSAR) and docking study with molecular operations environment (MOE; Molecular Simulation Informatics Systems [MOLSIS], Inc.) In the QSAR simulation, the QSAR model built using the partial least squares regression (PLS) and genetic algorithm-multiple linear regression (GA-MLR) methods showed remarkable coefficient of determination (R2) and XR2 values. In the docking study, a specific relationship was identified between the adjusted docking score (-S) and bioactivity (pKi) values. In conclusion, the methods developed could be useful for in silico risk assessment of LUTS, and plans are potentially applicable to numerous drugs with anticholinergic activity that induce serious side effects, limiting their use.


Assuntos
Antagonistas Colinérgicos/química , Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , Algoritmos , Sítios de Ligação , Antagonistas Colinérgicos/uso terapêutico , Humanos , Análise dos Mínimos Quadrados , Modelos Lineares , Sintomas do Trato Urinário Inferior/tratamento farmacológico , Sintomas do Trato Urinário Inferior/patologia , Receptor Muscarínico M3/química , Receptor Muscarínico M3/metabolismo
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