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1.
Cell Rep ; 42(5): 112479, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37178686

RESUMO

CREB/ATF transcription factor OASIS/CREB3L1 is upregulated in long-term-cultured astrocytes undergoing cell-cycle arrest due to loss of DNA integrity by repeated replication. However, the roles of OASIS in the cell cycle remain unexplored. We find that OASIS arrests the cell cycle at G2/M phase after DNA damage via direct induction of p21. Cell-cycle arrest by OASIS is dominant in astrocytes and osteoblasts, but not in fibroblasts, which are dependent on p53. In a brain injury model, Oasis-/- reactive astrocytes surrounding the lesion core show sustained growth and inhibition of cell-cycle arrest, resulting in prolonged gliosis. We find that some glioma patients exhibit low expression of OASIS due to high methylation of its promoter. Specific removal of this hypermethylation in glioblastomas transplanted into nude mice by epigenomic engineering suppresses the tumorigenesis. These findings suggest OASIS as a critical cell-cycle inhibitor with potential to act as a tumor suppressor.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Proteína Supressora de Tumor p53 , Camundongos , Animais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Camundongos Nus , Pontos de Checagem do Ciclo Celular , Fatores Ativadores da Transcrição/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo
2.
Plant Reprod ; 36(3): 255-262, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37099188

RESUMO

KEY MESSAGE: S29 haplotype does not require the MLPK function for self-incompatibility in Brassica rapa. Self-incompatibility (SI) in Brassicaceae is regulated by the self-recognition mechanism, which is based on the S-haplotype-specific direct interaction of the pollen-derived ligand, SP11/SCR, and the stigma-side receptor, SRK. M locus protein kinase (MLPK) is known to be one of the positive effectors of the SI response. MLPK directly interacts with SRK, and is phosphorylated by SRK in Brassica rapa. In Brassicaceae, MLPK was demonstrated to be essential for SI in B. rapa and Brassica napus, whereas it is not essential for SI in Arabidopsis thaliana (with introduced SRK and SP11/SCR from related SI species). Little is known about what determines the need for MLPK in SI of Brassicaceae. In this study, we investigated the relationship between S-haplotype diversity and MLPK function by analyzing the SI phenotypes of different S haplotypes in a mlpk/mlpk mutant background. The results have clarified that in B. rapa, all the S haplotypes except the S29 we tested need the MLPK function, but the S29 haplotype does not require MLPK for the SI. Comparative analysis of MLPK-dependent and MLPK-independent S haplotype might provide new insight into the evolution of S-haplotype diversity and the molecular mechanism of SI in Brassicaceae.


Assuntos
Brassica rapa , Brassica rapa/genética , Brassica rapa/metabolismo , Proteínas Quinases , Haplótipos , Sequência de Aminoácidos , Locos Secundários de Estimulação Linfocitária , Proteínas de Plantas/genética
3.
Int J Clin Pharmacol Ther ; 61(1): 16-23, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36366967

RESUMO

OBJECTIVE: Fractures are significantly associated with increased morbidity and mortality in older individuals; additionally, patients with diabetes mellitus are highly prone to fractures. The aim of the present study was to examine the association between dipeptidyl peptidase-4 (DPP-4) inhibitor use and the risk of fracture in older patients by analyzing data obtained from spontaneous adverse event reporting databases from the United States and Japan. MATERIALS AND METHODS: Data on older patients registered in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) from the first quarter of 2013 to the end of 2019 and data registered in the Japanese Adverse Drug Event Report database (JADER) from April 2004 to December 2019 were used. Reporting odds ratio (ROR) and information component (IC) values were used for disproportionality analysis. RESULTS: Significant inverse associations between DPP-4 inhibitor use and fracture were found for DPP-4 inhibitors as a whole (ROR = 0.80; 95% CI = 0.73 - 0.88; IC = -0.31, 95% CI = -0.46 to -0.17); linagliptin (ROR = 0.74; 95% CI = 0.59 - 0.94; IC = -0.42, 95% CI = -0.75 to -0.08); and sitagliptin (ROR = 0.77; 95% CI = 0.68 - 0.88; IC = -0.36, 95% CI = -0.55 to -0.17) in the analyses of FAERS data. Similarly, significant inverse associations were also found for DPP-4 inhibitors as whole (ROR = 0.71; 95% CI = 0.59 to 0.86; IC = -0.46, 95% CI = -0.74 to -0.18); sitagliptin (ROR = 0.70; 95% CI = 0.52 - 0.95; IC = -0.49, 95% CI = -0.93 to -0.05); and vildagliptin (ROR = 0.54; 95% CI = 0.35 - 0.83; IC = -0.85, 95% CI = -1.49 to -0.22) in the analyses of JADER data. CONCLUSION: Our analysis of adverse event databases using different algorithms revealed that DPP-4 inhibitor use was inversely associated with fracture in older patients.


Assuntos
Inibidores da Dipeptidil Peptidase IV , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Estados Unidos/epidemiologia , Idoso , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Preparações Farmacêuticas , United States Food and Drug Administration , Sistemas de Notificação de Reações Adversas a Medicamentos , Hipoglicemiantes/efeitos adversos , Fosfato de Sitagliptina , Bases de Dados Factuais
4.
Chem Pharm Bull (Tokyo) ; 70(4): 304-308, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35370209

RESUMO

Prodrugs have seen increased clinical applications as therapeutic agents, as they reduce undesirable side effects and improve the therapeutic potential of drugs. While microorganisms produce numerous secondary metabolites with useful medicinal properties, there are only a handful of naturally occurring prodrugs discovered to date. The techniques of isolating secondary metabolites with therapeutic potential from natural product producers have been developed extensively over the years. However, the methods of identifying prodrugs from microbes have not been examined in depth, partly because prodrug-type compounds inherently lack the biological activities that are often used to screen for therapeutically useful secondary metabolites. Therefore, we hypothesized that the difficulty in searching for natural prodrug-type compounds may be addressed by simulating human prodrug activation within natural product-producing microbes. We chose to introduce human CYP (hCYP) into natural product-producing filamentous fungi, because hCYPs are the key enzymes that activate prodrugs in human body, and filamentous fungi are known to be prolific producers of a wide variety of natural products. Here, we successfully identified a cytotoxic, antibiotic and potential anti-diabetic natural product leporin B from Aspergillus flavus that was previously not known to produce this compound. Through bioinformatic and metabolite analyses, we identified the prodrug-equivalent compound leporin C that is converted into leporin B by the action of the hCYP isoenzyme 3A4. By employing various prodrug-activating enzymes and microbes that biosynthesize diverse arrays of natural products, we should be able to probe wider biosynthetic space for identification of interesting prodrug-type natural products.


Assuntos
Produtos Biológicos , Pró-Fármacos , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Fungos/metabolismo , Humanos , Pró-Fármacos/farmacologia
5.
Biomater Sci ; 9(16): 5588-5598, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34241600

RESUMO

Macromolecular toxins often induce inflammatory cytokine production, multiple-organ dysfunction, and cell death. Synthetic polymer ligands (PLs) prepared with several functional monomers have the potential of neutralizing target toxins after binding to them; therefore, they are of significant interest as abiotic antidotes. Although PLs show little toxin neutralization effect in the bloodstream because of immediate elimination from there, the toxin neutralization effect is significantly improved by the direct decoration of PLs onto lipid nanoparticles (PL-LNPs). However, this direct decoration decreases PL mobility, induces LNP aggregation after capturing the target, and decreases LNP blood circulation time. We designed novel PL-LNPs to improve PL mobility, inhibit the aggregation tendency after capturing the target, and increase LNP blood circulation time in order to achieve highly effective toxin neutralization in vivo. Specifically, LNPs were modified with PLs-conjugated polyethylene glycol (PEG), and additional PEG was used to modify the PL-decorated LNPs (PL-PEG-LNPs). Histones were used as target toxins, and N-isopropylacrylamide-based PLs were used for histone capture. PEGylation increased the plasma LNP level 24 h after intravenous injection by ∼90 times and inhibited LNP aggregation after histone capture. The dissociation constant (Kd) of PL-PEG-LNPs against histone was two times smaller compared to that of PL-LNPs. Although PL-LNPs inhibited histone-platelet interaction in the bloodstream, a large amount of histone-PL-LNP complexes accumulated in the lungs because of aggregation. However, PL-PEG-LNPs inhibited both histone-platelet interaction and histone accumulation in the lungs. Importantly, PL-PEG-LNP treatment increased the survival rate of histone-treated mice compared to PL-LNPs. These results provide a platform for the development of abiotic antidote nanoparticles in vivo.


Assuntos
Nanopartículas , Polímeros , Animais , Ligantes , Lipídeos , Camundongos , Polietilenoglicóis , RNA Interferente Pequeno
6.
Mol Genet Genomics ; 296(2): 299-312, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33386986

RESUMO

Pseudomonas syringae pv. tabaci 6605 (Pta6605) is a causal agent of wildfire disease in host tobacco plants and is highly motile. Pta6605 has multiple clusters of chemotaxis genes including cheA, a gene encoding a histidine kinase, cheY, a gene encoding a response regulator, mcp, a gene for a methyl-accepting chemotaxis protein, as well as flagellar and pili biogenesis genes. However, only two major chemotaxis gene clusters, cluster I and cluster II, possess cheA and cheY. Deletion mutants of cheA or cheY were constructed to evaluate their possible role in Pta6605 chemotaxis and virulence. Motility tests and a chemotaxis assay to known attractant demonstrated that cheA2 and cheY2 mutants were unable to swarm and to perform chemotaxis, whereas cheA1 and cheY1 mutants retained chemotaxis ability almost equal to that of the wild-type (WT) strain. Although WT and cheY1 mutants of Pta6605 caused severe disease symptoms on host tobacco leaves, the cheA2 and cheY2 mutants did not, and symptom development with cheA1 depended on the inoculation method. These results indicate that chemotaxis genes located in cluster II are required for optimal chemotaxis and host plant infection by Pta6605 and that cluster I may partially contribute to these phenotypes.


Assuntos
Histidina Quinase/genética , Proteínas Quimiotáticas Aceptoras de Metil/genética , Pseudomonas aeruginosa/fisiologia , Pseudomonas syringae/fisiologia , Quimiotaxia , Resistência à Doença , Deleção de Genes , Histidina Quinase/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil/metabolismo , Família Multigênica , Filogenia , Doenças das Plantas/microbiologia , Pseudomonas aeruginosa/patogenicidade , Pseudomonas syringae/patogenicidade , Virulência
7.
Int J Mol Sci ; 21(11)2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32486221

RESUMO

Ubiquitylation plays multiple roles not only in proteasome-mediated protein degradation but also in various other cellular processes including DNA repair, signal transduction, and endocytosis. Ubiquitylation is mediated by ubiquitin ligases, which are predicted to be encoded by more than 600 genes in humans. RING finger (RNF) proteins form the majority of these ubiquitin ligases. It has also been predicted that there are 49 RNF proteins containing transmembrane regions in humans, several of which are specifically localized to membrane compartments in the secretory and endocytic pathways. Of these, RNF183, RNF186, RNF182, and RNF152 are closely related genes with high homology. These genes share a unique common feature of exhibiting tissue-specific expression patterns, such as in the kidney, nervous system, and colon. The products of these genes are also reported to be involved in various diseases such as cancers, inflammatory bowel disease, Alzheimer's disease, and chronic kidney disease, and in various biological functions such as apoptosis, endoplasmic reticulum stress, osmotic stress, nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR), and Notch signaling. This review summarizes the current knowledge of these tissue-specific ubiquitin ligases, focusing on their physiological roles and significance in diseases.


Assuntos
Ubiquitina-Proteína Ligases/fisiologia , Doença de Alzheimer/metabolismo , Animais , Apoptose , Estresse do Retículo Endoplasmático , Humanos , Inflamação , Doenças Inflamatórias Intestinais/metabolismo , Camundongos , NF-kappa B/metabolismo , Neoplasias/metabolismo , Pressão Osmótica , Filogenia , Ratos , Insuficiência Renal Crônica/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Ubiquitinação
8.
Genes Genet Syst ; 95(3): 111-118, 2020 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32493878

RESUMO

Recognition of self-incompatibility (SI) is regulated by the SRK and SP11 genes in Brassicaceae. Brassica rapa and B. oleracea are self-incompatible, while most cultivated species of B. napus, which arose from hybridization between B. rapa and B. oleracea, are self-compatible. Various studies of the SRK and SP11 genes in self-compatible B. napus have been reported, but details of the mechanism in different B. napus lines are not fully understood. In this study, we confirmed the S haplotypes, SI phenotypes and SP11 expression in 10 representative lines of B. napus, and identified two SI lines (N110 and N343) lacking SP11 expression. In N343 (with BnS1 and BnS6 haplotypes), we confirmed that there is a 3.6-kb insertion in the promoter region of BnSP11-1, and that BnSP11-1 and BnSP11-6 are not expressed, as reported previously (expression of BnSP11-6 is suppressed by the BnS1 haplotype), although this line is self-incompatible. Similarly, in N110, with two novel S haplotypes (BnS8 and BnS9) in addition to BnS6, a 4.3-kb insertion was identified in the promoter region of BnSP11-9, and expression levels of BnSP11-6, BnSP11-8 and BnSP11-9 were all suppressed (BnSP11-6 and BnSP11-8 may be suppressed by BnS8 and BnS9, respectively), although the phenotype was self-incompatible. This observation of an SI phenotype without SP11 expression suggests the existence of unknown factor(s) that induce pollen-stigma incompatibility in B. napus.


Assuntos
Brassica/genética , Proteínas de Plantas/genética , Autoincompatibilidade em Angiospermas , Brassica/fisiologia , Haplótipos , Proteínas de Plantas/metabolismo
9.
FASEB J ; 34(1): 865-880, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914686

RESUMO

Intramembrane cleavage of transmembrane proteins is a fundamental cellular process to produce important signals that elicit biological responses. These proteolytic events are known as regulated intramembrane proteolysis (RIP). ATF6 and BBF2H7 are transmembrane basic leucine zipper transcription factors and are subjected to RIP by site-1 protease (S1P) and site-2 protease (S2P) sequentially in response to endoplasmic reticulum (ER) stress. However, the detailed mechanisms responsible for RIP of the transcription factors, including the precise cutting sites, are still unknown. In this study, we demonstrated that S1P cleaves BBF2H7 just before the RXXL S1P recognition motif. Conversely, S2P cut at least three different sites in the membrane (next to Leu380, Met381, and Leu385), indicating that S2P cleaves the substrates at variable sites or via a multistep process. Interestingly, we found BBF2H7-derived small peptide (BSP) fragments located between the S1P and S2P cleavage sites in cells exposed to ER stress. Major type of BSP fragments was composed of 45 amino acid including partial transmembrane and luminal regions and easily aggregates like amyloid ß (Aß) protein. These results advance the understanding of poorly characterized ER stress-dependent RIP. Furthermore, the aggregable peptides produced by ER stress could link to the pathophysiology of neurodegenerative disorders.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/metabolismo , Proteólise , Fator 6 Ativador da Transcrição/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Humanos , Fragmentos de Peptídeos/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Transcrição Gênica/fisiologia
10.
Biochem Biophys Res Commun ; 521(4): 1030-1035, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31732153

RESUMO

We previously reported that RNF183, a member of the RING finger (RNF) protein family, is specifically expressed in the renal collecting duct and that RNF183 mRNA is induced by the activity of nuclear factor of activated T cells 5 (NFAT5), which regulates the transcription of essential proteins for adaptation to hypertonic conditions. The renal medulla is the only tissue that is continuously hypertonic; therefore, RNF183 possibly plays an important role in adaptation to continuous hypertonic conditions. However, the mechanism of how cells adapt to long-term hypertonicity via RNF183 remains unclear. In this study, the Na, K-ATPase α1 subunit was identified as a candidate substrate of RNF183 by the BirA proximity-biotinylation technique. The Na, K-ATPase α1 subunit acts as an ion transporter along with the Na, K-ATPase ß1 subunit at the plasma membrane. We confirmed that RNF183 interacted with both α1 and ß1 subunits; however, we found that RNF183 ubiquitinated only the ß1 subunit, not the α1 subunit. Furthermore, RNF183 translocated both α1 and ß1 subunits from the plasma membrane to lysosomes. In addition, the expression levels of α1 and ß1 subunits in HEK293 cells stably expressing RNF183 were significantly decreased compared with mock control cells, and were restored by siRNA-mediated knockdown of RNF183. Moreover, in RNF183-expressing cells, chloroquine treatment increased the protein levels of the α1 and ß1 subunits. Therefore, our results suggest that Na, K-ATPase α1 and ß1 subunits are degraded in lysosomes by RNF183-mediated ubiquitination of ß1 subunit.


Assuntos
Soluções Hipertônicas/farmacologia , Subunidades Proteicas/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células HEK293 , Células HeLa , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Camundongos , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacos
11.
Biochem Biophys Res Commun ; 514(2): 436-442, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31053298

RESUMO

Nuclear factor of activated T-cells 5 (NFAT5) directly binds to the promoter of the RING finger protein 183 (RNF183) gene and induces its transcription under hypertonic conditions in mouse inner-medullary collecting duct (mIMCD-3) cells. However, there is no specific anti-RNF183 antibody for immunostaining; therefore, it is unclear whether NFAT5 regulates RNF183 expression in vivo and where RNF183 is localized in the kidney. This study investigated NFAT5-regulated in vivo RNF183 expression and localization using CRISPR/Cas9-mediated RNF183-green fluorescent protein (RNF183-GFP) knock-in mice. GFP with linker sequences was introduced upstream of an RNF183 open reading frame in exon 3 by homologous recombination through a donor plasmid. Immunofluorescence staining using GFP antibody revealed that GFP signals gradually increase from the outer medulla down to the inner medulla and colocalize with aquaporin-2. Furosemide treatment dramatically decreased RNF183 expression in the renal medulla, consistent with the decrease in NFAT5 protein and target gene mRNA expression. Furosemide treatment of mIMCD-3 cells did not affect mRNA expression and RNF183 promoter activities. These results indicated that RNF183 is predominantly expressed in the renal medullary collecting ducts, and that decreased renal medullary tonicity by furosemide treatment decreases RNF183 expression by NFAT5 downregulation.


Assuntos
Regulação da Expressão Gênica , Medula Renal/fisiologia , Túbulos Renais Coletores/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Sistemas CRISPR-Cas/genética , Regulação para Baixo/efeitos dos fármacos , Feminino , Furosemida/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Introdução de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Masculino , Camundongos
12.
Sci Rep ; 9(1): 20301, 2019 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-31889078

RESUMO

RNF183 is a ubiquitin ligase containing RING-finger and transmembrane domains, and its expression levels are increased in patients with inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, and in 2,4,6-trinitrobenzene sulfonic acid-induced colitis mice. Here, we further demonstrate that RNF183 was induced to a greater degree in the dextran sulfate sodium (DSS)-treated IBD model at a very early stage than were inflammatory cytokines. In addition, fluorescence-activated cell sorting and polymerase chain reaction analysis revealed that RNF183 was specifically expressed in epithelial cells of DSS-treated mice, which suggested that increased levels of RNF183 do not result from the accumulation of immune cells. Furthermore, we identified death receptor 5 (DR5), a member of tumour necrosis factor (TNF)-receptor superfamily, as a substrate of RNF183. RNF183 mediated K63-linked ubiquitination and lysosomal degradation of DR5. DR5 promotes TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis signal through interaction with caspase-8. Inhibition of RNF183 expression was found to suppress TRAIL-induced activation of caspase-8 and caspase-3. Thus, RNF183 promoted not only DR5 transport to lysosomes but also TRAIL-induced caspase activation and apoptosis. Together, our results provide new insights into potential roles of RNF183 in DR5-mediated caspase activation in IBD pathogenesis.


Assuntos
Doenças Inflamatórias Intestinais/metabolismo , Lisossomos/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Apoptose , Biomarcadores , Linhagem Celular , Modelos Animais de Doenças , Suscetibilidade a Doenças , Expressão Gênica , Humanos , Imuno-Histoquímica , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/patologia , Camundongos , Mucosa/metabolismo , Mucosa/patologia , Ligação Proteica , Transporte Proteico , Proteólise , RNA Mensageiro , Índice de Gravidade de Doença , Especificidade por Substrato , Ubiquitina-Proteína Ligases/genética
13.
J Biol Chem ; 294(1): 101-115, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30413537

RESUMO

We previously reported that among the 37 RING finger protein (RNF) family members, RNF183 mRNA is specifically expressed in the kidney under normal conditions. However, the mechanism supporting its kidney-specific expression pattern remains unclear. In this study, we elucidated the mechanism of the transcriptional activation of murine Rnf183 in inner-medullary collecting duct cells. Experiments with anti-RNF183 antibody revealed that RNF183 is predominantly expressed in the renal medulla. Among the 37 RNF family members, Rnf183 mRNA expression was specifically increased in hypertonic conditions, a hallmark of the renal medulla. RNF183 up-regulation was consistent with the activation of nuclear factor of activated T cells 5 (NFAT5), a transcription factor essential for adaptation to hypertonic conditions. Accordingly, siRNA-mediated knockdown of NFAT5 down-regulated RNF183 expression. Furthermore, the -3,466 to -3,136-bp region upstream of the mouse Rnf183 promoter containing the NFAT5-binding motif is conserved among mammals. A luciferase-based reporter vector containing the NFAT5-binding site was activated in response to hypertonic stress, but was inhibited by a mutation at the NFAT5-binding site. ChIP assays revealed that the binding of NFAT5 to this DNA site is enhanced by hypertonic stress. Of note, siRNA-mediated RNF183 knockdown increased hypertonicity-induced caspase-3 activation and decreased viability of mIMCD-3 cells. These results indicate that (i) RNF183 is predominantly expressed in the normal renal medulla, (ii) NFAT5 stimulates transcriptional activation of Rnf183 by binding to its cognate binding motif in the Rnf183 promoter, and (iii) RNF183 protects renal medullary cells from hypertonicity-induced apoptosis.


Assuntos
Regulação Enzimológica da Expressão Gênica , Túbulos Renais Coletores/metabolismo , Pressão Osmótica , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/biossíntese , Regulação para Cima , Animais , Caspase 3/genética , Caspase 3/metabolismo , Células HEK293 , Células HeLa , Humanos , Túbulos Renais Coletores/citologia , Camundongos , Elementos de Resposta , Fatores de Transcrição/genética , Transcrição Gênica , Ubiquitina-Proteína Ligases/genética
14.
Biochem Biophys Res Commun ; 496(4): 1122-1127, 2018 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-29397936

RESUMO

In mammals, four ATP-binding cassette (ABC) proteins belonging to subfamily D have been identified. ABCD1‒3 are located on peroxisomal membrane and play an important role in the transportation of various fatty acid-CoA derivatives, including very long chain fatty acid-CoA, into peroxisomes. ABCD4 is located on lysosomal membrane and is suggested to be involved in the transport of vitamin B12 from lysosomes to the cytosol. However, the precise transport mechanism by which these ABC transporters facilitate the import or export of substrate has yet to be well elucidated. In this study, the overexpression of human ABCD1‒4 in the methylotrophic yeast Pichia pastoris and a purification procedure were developed. The detergent-solubilized proteins were reconstituted into liposomes. ABCD1‒4 displayed stable ATPase activity, which was inhibited by AlF3. Furthermore, ABCD1‒4 were found to possess an equal levels of acyl-CoA thioesterase activity. Proteoliposomes is expected to be an aid in the further biochemical characterization of ABCD transporters.


Assuntos
Subfamília D de Transportador de Cassetes de Ligação de ATP/química , Lipossomos/química , Proteolipídeos/química , Sítios de Ligação , Ativação Enzimática , Estabilidade Enzimática , Cinética , Ligação Proteica
15.
Gels ; 3(1)2017 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-30920508

RESUMO

Stimuli-responsive colloidal nanocomposite hydrogels are prepared by exploiting non-covalent interactions between anionic cellulose nanocrystals and polycationic delaminated sheets of aminopropyl-functionalized magnesium phyllosilicate clays.

16.
Sci Rep ; 6: 30183, 2016 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-27456980

RESUMO

We previously demonstrated that ABCD4 does not localize to peroxisomes but rather, the endoplasmic reticulum (ER), because it lacks the NH2-terminal hydrophilic region required for peroxisomal targeting. It was recently reported that mutations in ABCD4 result in a failure to release vitamin B12 from lysosomes. A similar phenotype is caused by mutations in LMBRD1, which encodes the lysosomal membrane protein LMBD1. These findings suggested to us that ABCD4 translocated from the ER to lysosomes in association with LMBD1. In this report, it is demonstrated that ABCD4 interacts with LMBD1 and then localizes to lysosomes, and this translocation depends on the lysosomal targeting ability of LMBD1. Furthermore, endogenous ABCD4 was localized to both lysosomes and the ER, and its lysosomal localization was disturbed by knockout of LMBRD1. To the best of our knowledge, this is the first report demonstrating that the subcellular localization of the ABC transporter is determined by its association with an adaptor protein.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Retículo Endoplasmático/metabolismo , Lisossomos/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Linhagem Celular , Humanos , Mutação , Proteínas de Transporte Nucleocitoplasmático/genética , Transporte Proteico , Frações Subcelulares/metabolismo
17.
J Nanosci Nanotechnol ; 15(9): 7117-20, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26716294

RESUMO

We succeeded to use hydrothermal treatment to insert prefabricated Pt-loaded Ce0.5Zr0.5O2 (PtCZ) nanoparticles into the mesopores of the SBA-16 mesoporous silica without disordering of the mesoporous structure. Samples prepared by the hydrothermal treatment exhibited superior oxygen storage capacity compared to that of simple dry mixed sample. The oxygen storage capacity of the hydrothermally treated PtCZ is attributed to the localized PtCZ nanoparticles inside the mesopores of the SBA-16. FTIR analysis suggested that the PtCZ nanoparticles inside the mesopores possess the Si-O-Zr linkages that are bonded to the inner walls of the SBA-16 host. This linkage is the key reason for the superior oxygen storage capacity of PtCZ localized in the mesopores by hydrothermal treatment. It is considered that the formation of the Si-O-Zr linkage in the hydrothermally treated samples resulted in crystalline distortions of Ce0.5Zr0.5O2 nanoparticles inside the mesopores, and which contribute to enhance the oxygen storage capacity of PtCZ.

18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 2997-3000, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26736922

RESUMO

With the increase of colorectal cancer patients in recent years, the needs of quantitative evaluation of colorectal cancer are increased, and the computer-aided diagnosis (CAD) system which supports doctor's diagnosis is essential. In this paper, a hardware design of type identification module in CAD system for colorectal endoscopic images with narrow band imaging (NBI) magnification is proposed for real-time processing of full high definition image (1920 × 1080 pixel). A pyramid style image segmentation with SVMs for multi-size scan windows, which can be implemented on an FPGA with small circuit area and achieve high accuracy, is proposed for actual complex colorectal endoscopic images.


Assuntos
Neoplasias Colorretais , Colonoscopia , Diagnóstico por Computador , Humanos , Imagem de Banda Estreita , Máquina de Vetores de Suporte
19.
Biochem Biophys Res Commun ; 453(3): 612-8, 2014 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-25301552

RESUMO

In mammals, four ATP-binding cassette (ABC) proteins belonging to subfamily D have been identified. ABCD1-3 possesses the NH2-terminal hydrophobic region and are targeted to peroxisomes, while ABCD4 lacking the region is targeted to the endoplasmic reticulum (ER). Based on hydropathy plot analysis, we found that several eukaryotes have ABCD protein homologs lacking the NH2-terminal hydrophobic segment (H0 motif). To investigate whether the role of the NH2-terminal H0 motif in subcellular localization is conserved across species, we expressed ABCD proteins from several species (metazoan, plant and fungi) in fusion with GFP in CHO cells and examined their subcellular localization. ABCD proteins possessing the NH2-terminal H0 motif were localized to peroxisomes, while ABCD proteins lacking this region lost this capacity. In addition, the deletion of the NH2-terminal H0 motif of ABCD protein resulted in their localization to the ER. These results suggest that the role of the NH2-terminal H0 motif in organelle targeting is widely conserved in living organisms.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Frações Subcelulares/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Animais , Arabidopsis/metabolismo , Células CHO , Caenorhabditis elegans/metabolismo , Cricetinae , Cricetulus , Células Eucarióticas/metabolismo , Imunofluorescência , Interações Hidrofóbicas e Hidrofílicas
20.
Chem Pharm Bull (Tokyo) ; 53(12): 1547-50, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16327186

RESUMO

Scale-up of wet granulation in a vertical high shear mixer was conducted. Pharmaceutical excipient mixtures composed of lactose, cornstarch and micro-crystalline cellulose, and hydroxypropylecellulose as a binder were mixed together and then granulated with purified water under various operating conditions and vessel scales. Torque of agitator shaft was continuously measured and then agitation power per unit vessel volume was calculated. The agitation power per unit vessel volume showed a good correlation with physical properties of obtained granules, such as mass median diameter, strength and compressibility. This implied that the scale-up characteristics could be well analyzed by means of the agitation power per unit vessel volume. In addition, the effects of agitator tip speed and Froude number on the agitation power per unit vessel volume were investigated. The results showed that the agitation power per unit vessel volume was well characterized by the tip speed rather than the Froude number. This meant that the granule growth mainly progressed by the shear stress from the agitator blade. Dynamic characteristics of high shear granulation were also discussed here.


Assuntos
Pós , Algoritmos , Química Farmacêutica , Composição de Medicamentos , Excipientes , Tamanho da Partícula , Água
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