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1.
Gastroenterology ; 150(7): 1620-1632, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26965517

RESUMO

BACKGROUND & AIMS: Attachment of a fucose molecule to the innermost N-glycan in a glycoprotein (core fucosylation) regulates the activity of many growth factor receptors and adhesion molecules. The process is catalyzed by α1-6 fucosyltransferase (FUT8) and required for immune regulation, but it is not clear whether this process is dysregulated during disease pathogenesis. We investigated whether core fucosylation regulates T-cell activation and induction of colitis in mice, and is altered in patients with inflammatory bowel disease (IBD). METHODS: Biopsy samples were collected from inflamed and noninflamed regions of intestine from patients (8 with Crohn's disease, 4 with ulcerative colitis, and 4 without IBD [controls]) at Osaka University Hospital. Colitis was induced in FUT8-deficient (Fut8(-/-)) mice and Fut8(+/+) littermates by administration of trinitrobenzene sulfonic acid. Intestinal tissues were collected and analyzed histologically. Immune cells were collected and analyzed by lectin flow cytometry, immunofluorescence, and reverse-transcription polymerase chain reaction, as well as for production of cytokines and levels of T-cell receptor (TCR) in lipid raft fractions. T-cell function was analyzed by intraperitoneal injection of CD4(+)CD62L(+) naïve T cells into RAG2-deficient mice. RESULTS: Levels of core fucosylation were increased on T cells from mice with colitis, compared with mice without colitis, as well as on inflamed mucosa from patients with IBD, compared with their noninflamed tissues or tissues from control patients. Fut8(-/-) mice developed less-severe colitis than Fut8(+/+) mice, and T cells from Fut8(-/-) mice produced lower levels of T-helper 1 and 2 cytokines. Adoptive transfer of Fut8(-/-) T cells to RAG2-deficient mice reduced the severity of colitis. Compared with CD4(+) T cells from Fut8(+/+) mice, those from Fut8(-/-) mice expressed similar levels of TCR and CD28, but these proteins did not contain core fucosylation. TCR complexes formed on CD4(+) T cells from Fut8(-/-) mice did not signal properly after activation and were not transported to lipid rafts. CONCLUSIONS: Core fucosylation of the TCR is required for T-cell signaling and production of inflammatory cytokines and induction of colitis in mice. Levels of TCR core fucosylation are increased on T cells from intestinal tissues of patients with IBD; this process might be blocked as a therapeutic strategy.


Assuntos
Colite Ulcerativa/imunologia , Colite/imunologia , Doença de Crohn/imunologia , Fucosiltransferases/metabolismo , Linfócitos T/metabolismo , Transferência Adotiva , Adulto , Animais , Biópsia , Estudos de Casos e Controles , Colite/induzido quimicamente , Colite/metabolismo , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Feminino , Fucose/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Intestinos/patologia , Ativação Linfocitária , Masculino , Camundongos , Transdução de Sinais
2.
Hepatol Res ; 47(9): 902-909, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27615366

RESUMO

AIM: We identified Mac-2 (galectin-3) binding protein (Mac-2bp) as a novel diagnostic and liver fibrosis predicting biomarker for nonalcoholic steatohepatitis in humans. In mouse models, there are no serum biomarkers predicting liver disease severity. In this study, we developed a mouse Mac-2bp enzyme-linked immunosorbent assay (ELISA) system and determined its efficacy for predicting the severity of liver disease in mouse models, especially in non-alcoholic fatty liver disease (NAFLD) models. METHODS: We established several rat monoclonal antibodies against mouse Mac-2bp, selected two clones for the ELISA, and checked the accuracy and reproducibility of the ELISA, especially for NAFLD models and liver fibrosis models. We also investigated the relationships between serum levels and hepatic gene expression of Mac-2bp in mouse models. RESULTS: Our ELISA system had high accuracy and reproducibility (R2 = 0.999). The intra-assay and inter-assay results for the coefficient of variation were 2.0-3.7% and 1.7-6.9%, respectively. The levels of bilirubin, hemoglobin, and chyle did not affect the Mac-2bp serum levels detected by our ELISA kit. In the mouse models, serum Mac-2bp levels increased with liver disease progression (F0/F1/F2/F3, 239.1 ± 36.7 / 259.1 ± 43.0 / 457.5 ± 162.0 / 643.7 ± 116.0 ng/mL; P < 0.0001), and were significantly correlated with hepatic gene expression of Mac-2bp (R = 0.42, P < 0.0001). CONCLUSION: Our mouse Mac-2bp ELISA system effectively predicts severity of NAFLD and liver fibrosis in mouse models.

3.
Am J Physiol Gastrointest Liver Physiol ; 311(5): G859-G868, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27659420

RESUMO

Glycosylation is involved in various pathophysiological conditions. N-Acetylglucosaminyltransferase V (GnT-V), catalyzing ß1-6 branching in asparagine-linked oligosaccharides, is one of the most important glycosyltransferases involved in cancer and the immune system. Recent findings indicate that aberrant N-glycan structure can modify lipid metabolism. In this study, we investigated the effects of aberrant glycosylation by GnT-V on high-density lipoprotein cholesterol (HDL) assembly. We used GnT-V transgenic (Tg) mice and GnT-V Hep3B cell (human hepatoma cell line) transfectants. The study also included 96 patients who underwent medical health check-ups. Total serum cholesterol levels, particularly HDL-cholesterol (HDL-C) levels, were significantly increased in Tg vs. wild-type (WT) mice. Hepatic expression of apolipoprotein AI (ApoAI) and ATP-binding cassette subfamily A member 1 (ABCA1), two important factors in HDL assembly, were higher in Tg mice compared with WT mice. ApoAI and ABCA1 were also significantly elevated in GnT-V transfectants compared with mock-transfected cells. Moreover, ApoAI protein in the cultured media of GnT-V transfectants was significantly increased. Finally, we found a strong correlation between serum GnT-V activity and HDL-C concentration in human subjects. Multivariate logistic analyses demonstrated that GnT-V activity was an independent and significant determinant for serum HDL-C levels even adjusted with age and gender differences. Further analyses represented that serum GnT-V activity had strong correlation especially with the large-size HDL particle concentration. These findings indicate that enhanced hepatic GnT-V activity accelerated HDL assembly and could be a novel mechanism for HDL synthesis.


Assuntos
Lipoproteínas HDL/metabolismo , Fígado/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Animais , Apolipoproteínas A/metabolismo , Linhagem Celular Tumoral , Feminino , Glicosilação , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Fosforilação
4.
Hepatology ; 62(5): 1433-43, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26199205

RESUMO

UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) is a growing medical problem; thus, discriminating nonalcoholic steatohepatitis (NASH) from NAFLD is of great clinical significance. For the diagnosis of NASH, liver biopsy-proven histological examination is the current gold standard, and noninvasive and reliable biomarkers are greatly needed. Recently, we found that two glycobiomarkers, fucosylated haptoglobin (Fuc-Hpt) and Mac-2 binding protein (Mac2bp), are useful independently for NASH diagnosis. In this study, we confirmed that serum Fuc-Hpt is suitable for the prediction of ballooning hepatocytes and that serum Mac2bp is suitable for the prediction of liver fibrosis severity in 124 biopsy-proven NAFLD patients (training cohort). In addition, we found that the combination of serum Fuc-Hpt and Mac2bp levels was an excellent tool for NASH diagnosis. Using receiver operating characteristic analyses, the area under the receiver operating characteristic curve, sensitivity, and specificity of the combination of these two glycobiomarkers were 0.854, 81.1%, and 79.3%, respectively. We established a prediction model for NASH diagnosis using logistic regression analysis: logit (p)=-2.700+0.00242×Fuc-Hpt+1.225×Mac2bp. To validate the prediction model, another 382 biopsy-proven NAFLD patients were enrolled (validation cohort). In the validation cohort, the area under the receiver operating characteristic curve of this model for NASH diagnosis was 0.844, with 71.4% and 82.3% sensitivity and specificity, respectively. In addition, we investigated the significance of our developed NASH diagnosis model in ultrasound-diagnosed NAFLD subjects who received medical health checkups (n = 803). Our model also could predict NAFLD disease severity in this larger population. CONCLUSION: The combination of serum Fuc-Hpt and Mac2bp can distinguish NASH from NAFLD patients. Our noninvasive model using two serum glycobiomarkers contributes to a novel NASH diagnostic methodology that could replace liver biopsy.


Assuntos
Antígenos de Neoplasias/sangue , Biomarcadores/sangue , Fucose/metabolismo , Haptoglobinas/análise , Glicoproteínas de Membrana/sangue , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Adulto , Idoso , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Curva ROC
5.
Pancreatology ; 16(2): 238-43, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26897254

RESUMO

BACKGROUND/OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis of all malignancies, and its diagnosis in early stages is the most important prognostic factor. Chronic pancreatitis (CP), a common background of PDAC occurrence, is morphologically defined as progressive pancreatic fibrosis and inflammation accompanied by pancreatic exocrine cell atrophy. We recently found that inflammation and fibrosis are independent characteristic histological changes in noncancerous lesions in PDAC patients despite the absence of a past history of clinical CP. Subclinical CP is an important background for PDAC occurrence. Therefore, there is an urgent need to develop a noninvasive and reliable biomarker for CP diagnosis. METHODS: Fifty-nine healthy volunteers (HV), 159 patients with CP, and 83 patients with PDAC were enrolled in this study. We measured serum total fucosylated haptoglobin (Fuc-Hpt) and core-Fuc-Hpt levels using lectin-antibody enzyme-linked immunosorbent assay kits that we developed. In these kits, total Fuc-Hpt and core-Fuc-Hpt were measured using Aleuria aurantia lectin and Pholiota squarrosa lectin, respectively. RESULTS: Serum Fuc-Hpt levels were significantly increased in CP patients compared to HV (P < 0.0001) and were further increased in PDAC patients (P < 0.0001). Interestingly, serum core-Fuc-Hpt levels were significantly higher in CP patients compared to HV (P < 0.0001) and PDAC patients (P < 0.0001). Multivariate analyses demonstrated that total serum core-Fuc-Hpt was an independent determinant for CP diagnosis, but Fuc-Hpt was not. CONCLUSIONS: A dramatic change in oligosaccharides was observed in serum haptoglobin between CP and PDAC. Serum core-Fuc-Hpt may be a novel and useful biomarker for CP diagnosis.


Assuntos
Haptoglobinas/metabolismo , Pancreatite Crônica/sangue , Pancreatite Crônica/metabolismo , Adulto , Idoso , Biomarcadores , Feminino , Expressão Gênica , Haptoglobinas/genética , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatite Crônica/diagnóstico
6.
Hepatol Res ; 46(3): E118-29, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26041473

RESUMO

AIM: Glycosylation changes induce various types of biological phenomena in human diseases. N-Acetylglucosaminyltransferase V (GnT-V) is one of the most important glycosyltransferases involved in cancer biology. Recently, many researchers have challenged studies of lipid metabolism in cancer. To elucidate the relationships between cancer and lipid metabolism more precisely, we investigated the effects of GnT-V on lipid metabolism. In this study, we investigated the effects of aberrant glycosylation by GnT-V on hepatic triglyceride production. METHODS: We compared lipid metabolism in GnT-V transgenic (Tg) mice with that of wild-type (WT) mice fed with normal chow or a choline-deficient amino acid-defined (CDAA) diet in vivo. HepG2 cells and GnT-V transfectants of Hep3B cells were used in an in vitro study. RESULTS: Serum triglyceride levels and hepatic very low-density lipoprotein (VLDL) secretion in Tg mice were significantly elevated compared with that of WT mice. Hepatic lipogenic genes (Lxrα, Srebp1, Fas and Acc) and VLDL secretion-related gene (Mttp1) were significantly higher in Tg mice. Expression of these genes was also significantly higher in GnT-V transfectants than in mock cells. Knockdown of GnT-V decreased, while both epidermal growth factor and transforming growth factor-ß1 stimulation increased LXRα gene expression in HepG2 cells. Finally, we found that the blockade of VLDL secretion by CDAA diet induced massive hepatic steatosis in Tg mice. CONCLUSION: Our study demonstrates that enhancement of hepatic GnT-V activity accelerates triglyceride synthesis and VLDL secretion. Glycosylation modification by GnT-V regulation could be a novel target for a therapeutic approach to lipid metabolism.

7.
Liver Int ; 35(3): 925-35, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25627311

RESUMO

BACKGROUND & AIMS: Fetuin-A (α2HS-glycoprotein), a liver secretory glycoprotein, is known as a transforming growth factor (TGF)-ß1 signalling inhibitor. Serum fetuin-A concentration is associated with nonalcoholic fatty liver disease (NAFLD) and cardiovascular disease. However, the usefulness of serum fetuin-A as a predictive fibrosis biomarker in NAFLD patients remains unclear. In this study, we investigated the relationship between circulating fetuin-A levels and fibrosis-related markers [platelet count, NAFLD fibrosis score and carotid intima media thickness (IMT)] in subjects with NAFLD. METHODS: A total of 295 subjects (male, 164; female, 131) who received medical health check-ups were enrolled in this study. NAFLD was diagnosed using abdominal ultrasonography. Serum fetuin-A was measured by ELISA. IMT was assessed using a high-resolution ultrasound scanner. Using recombinant human fetuin-A, we investigated the effects of fetuin-A on hepatic stellate cells, which play a pivotal role in the process of hepatic fibrosis. RESULTS: Serum fetuin-A concentration was significantly correlated with platelet count (R = 0.19, P < 0.01), NAFLD fibrosis score (R = -0.25, P < 0.01) and mean IMT (R = -0.22, P < 0.01). Multivariate analyses revealed that the fetuin-A concentration is a significant and independent determinant of platelet count, NAFLD fibrosis score and mean IMT. Recombinant fetuin-A suppressed TGF-ß1 signalling and fibrosis-related gene expression and increased the expression of TGF-ß1 pseudoreceptor bone morphogenic protein and activin membrane-bound inhibitor (BAMBI). CONCLUSIONS: Serum fetuin-A level is associated with liver/vessel fibrosis-related markers in NAFLD patients. Circulating fetuin-A could be a useful serum biomarker for predicting liver and vascular fibrosis progression in NAFLD patients.


Assuntos
Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/sangue , alfa-2-Glicoproteína-HS/metabolismo , Idoso , Biomarcadores/sangue , Espessura Intima-Media Carotídea , Linhagem Celular , Feminino , Fibrose , Células Estreladas do Fígado/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/patologia , Contagem de Plaquetas , Fator de Crescimento Transformador beta1
8.
Gastroenterology ; 142(5): 1172-82, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22333949

RESUMO

BACKGROUND & AIMS: Oligosaccharide modifications induce various functional changes in immune cells. The galactose-deficient fraction of fucosylated IgG oligosaccharides is increased, whereas that of ß-1,4-galactosyltransferase I (B4GalTI) is reduced, in patients with Crohn's disease. We investigated the role of oligosaccharide modification in the pathophysiology of colitis using B4galt1-deficient mice. METHODS: Colitis severity was compared between B4galt1(+/-) and B4galt1(+/+) mice. B cells isolated from B4galt1(+/-) and B4galt1(+/+) mice were adoptively transferred to recombination activating gene 2(-/-) mice, in which colitis was induced by administration of CD4(+)CD62L(+) T cells. Cell-surface glycan profiles were determined by lectin microarray analysis. Cytokine production was determined in a coculture of various types of cells isolated from either B4galt1(+/-) or B4galt1(+/+) mice. RESULTS: Colitis induction by dextran sodium sulfate or trinitrobenzene sulfonic acid was significantly reduced in B4galt1(+/-) mice, which had galactose deficiency in IgG oligosaccharides (similar to patients with Crohn's disease) compared with B4galt1(+/+) mice. Amelioration of colitis was associated with increased production of interleukin-10 by macrophages in B4galt1(+/-) mice. Colitis induction in recombination activating gene 2(-/-) mice by administration of CD4(+)CD62L(+) T cells was reduced by cotransfer of B cells isolated from B4galt1(+/-), but not from B4galt1(+/+) mice. Lectin microarray analysis revealed increased expression of polylactosamines on B4galt1(+/-) B cells and macrophages, compared with B4galt1(+/+) cells. The production of interleukin-10 from macrophages was induced via their direct interaction with B4galt1(+/-) B cells. CONCLUSIONS: Altered oligosaccharide structures on immune cells modulate mucosal inflammation. Oligosaccharides in immune cells might be a therapeutic target for inflammatory bowel diseases.


Assuntos
Colite/prevenção & controle , Galactosiltransferases/fisiologia , Oligossacarídeos/fisiologia , Animais , Antígeno CD11b/análise , Comunicação Celular , Colite/imunologia , Galectinas/fisiologia , Interleucina-10/biossíntese , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Oligossacarídeos/química
10.
J Biochem ; 165(3): 227-237, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30445455

RESUMO

Core fucosylation, catalysed by α-1, 6 fucosyltransferase (FUT8), regulates growth factor receptors in immune function. Although core fucose regulates many immune cell types, few reports confront the association between core fucose activity and an innate immune reaction. Here, we have investigated the function of core fucose in macrophages in vivo and in vitro using Fut8-deficient mice and cells. Following lipopolysaccharide (LPS) stimulation, inflammatory cytokine production in Fut8-deficient (Fut8-/-) macrophages was suppressed in both in vivo and in vitro experiments. Because LPS is recognized by Toll-like receptor 4 (TLR4), which induces the signalling cascade, TLR4 signalling was assumed to be impaired in Fut8-/- cells. Flow cytometry analyses revealed, however, that a lack of core fucose reduced the expression of, not TLR4, but CD14, which is necessary for TLR4 endocytosis. Because CD14 is necessary for TLR2 signalling, the immune response of TLR2 was also impaired in Fut8-/- macrophages. Moreover, in the dextran sodium sulphate (DSS)-induced murine colitis model, the mice grafted with Fut8-/- bone marrow cells exhibited higher resistance to inflammation than those grafted with Fut8+/+ bone marrow cells. These findings indicate that core fucose is essential for CD14-dependent TLR4 and TLR2 signalling in murine macrophage activity, leading to DSS-induced experimental colitis.


Assuntos
Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/metabolismo , Transdução de Sinais , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células Cultivadas , Glicosilação , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Células RAW 264.7
11.
J Biochem ; 161(5): 409-415, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28338836

RESUMO

Oligosaccharide modifications play an essential role in various inflammatory diseases and cancers, but their pathophysiologic roles, especially in inflammation, are not clear. Inflammatory bowel disease (IBD) is an intractable chronic inflammatory disorder with an unknown aetiology, and the number of patients with IBD is increasing throughout the world. Certain types of immunosuppressant drugs, such as corticosteroids, are effective for IBD, suggesting that immune function is closely associated with the pathophysiology of IBD. Recent progress in the analysis of oligosaccharides revealed a role for oligosaccharides in intestinal inflammation based on both experimental models and human samples from IBD patients. Moreover, changes in the oligosaccharide structures on glycoproteins in the sera and tissue samples may serve as biomarkers of IBD. Here, we present current studies of IBD with regard to the immunologic aspects of glycobiology, suggesting a novel concept for IBD pathogenesis and the function of oligosaccharides on immune cells, termed "glyco-immunology".


Assuntos
Imunoglobulinas/imunologia , Doenças Inflamatórias Intestinais/imunologia , Oligossacarídeos/imunologia , Biomarcadores/sangue , Humanos , Imunoglobulinas/química , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Oligossacarídeos/química
12.
Inflamm Bowel Dis ; 23(12): 2172-2179, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28945638

RESUMO

BACKGROUND: Many reports indicate that a high-serum trough level of anti-tumor necrosis factor (TNF) agents is required for sustained remission in patients with Crohn's disease The pharmacokinetics of anti-TNF agents in inflamed intestinal tissue, however, is not well investigated. We investigated the association between the tissue concentration of anti-TNF agents and long-term disease outcome. METHODS: This was a prospective single-center study that enrolled 25 patients with Crohn's disease who were administered infliximab or adalimumab. All participants underwent endoscopy 2 weeks after administration of the anti-TNF agents, and biopsy samples were obtained from both inflamed and noninflamed intestinal tissue. Tissue concentrations of anti-TNF agents were evaluated and the correlation with serum trough levels was compared. The relation between the tissue drug concentration and clinical course over 24 months was also investigated. RESULTS: Concentrations of anti-TNF agents were significantly higher in inflamed tissue than in noninflamed tissue. Patients with high-serum trough concentrations of anti-TNF agents had significantly higher drug levels in the noninflamed tissue than those with low-serum trough concentrations, but no difference in the levels was detected in the inflamed tissue. Patients with high-drug levels in the noninflamed tissue had a significantly higher sustained response rate than patients with low-drug levels. CONCLUSIONS: Concentrations of anti-TNF agents in the noninflamed tissue can reflect sustained remission and may be a useful biomarker for monitoring therapeutic intensity in patients with Crohn's disease treated with anti-TNF agents (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B623).


Assuntos
Adalimumab/farmacocinética , Doença de Crohn/tratamento farmacológico , Infliximab/farmacocinética , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/uso terapêutico , Adulto , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/uso terapêutico , Colonoscopia , Doença de Crohn/patologia , Feminino , Humanos , Infliximab/uso terapêutico , Intestinos/efeitos dos fármacos , Intestinos/patologia , Japão , Estimativa de Kaplan-Meier , Masculino , Estudos Prospectivos , Índice de Gravidade de Doença
13.
J Phys Chem B ; 110(26): 12964-8, 2006 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-16805600

RESUMO

In this work, the hydrogen desorption and structural properties of the Li-Mg-N-H systems with different LiH/Mg(NH2)2 ratios are systemically investigated. The results indicate that the system with the LiH/Mg(NH2)2 ratio of 6/3 transforms into Li2NH and MgNH, and then, the mixture forms an unknown phase by a solid-solid reaction, which presumably is the ternary imide Li2Mg(NH)2; the system with the LiH/Mg(NH2)2 ratio of 8/3 transforms into 4Li2NH and Mg3N2 after releasing H2 at T < 400 degrees C; the system with the LiH/Mg(NH2)2 ratio of 12/3 transforms into 4Li3N and Mg3N2 after releasing H2 at T > 400 degrees C, where the LiMgN phase is formed by the reaction between Li3N and Mg3N2. The characteristics of the phase transformations and the thermal gas desorption behaviors in these Li-Mg-N-H systems could be reasonably explained by the ammonia mediated reaction model, irrespective of the difference in the LiH/Mg(NH2)2 ratios.

14.
Proteomics Clin Appl ; 10(4): 384-90, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26427763

RESUMO

The intestine is one of the most important organs associated with the immune system. It is thought that disruption of intestinal immunity causes inflammatory bowel disease (IBD). Recent advances in immune glycobiology have provided novel insights into many human diseases. For example, studies of glycosylation remodeling in mice have underscored the importance of oligosaccharides in the pathogenesis of IBD. Furthermore, aberrant glycosylation of IgG is a good serum marker of IBD activity. In this review, we examine current understanding of the role of aberrant glycosylation in the pathogenesis of IBD in terms of our original data and recent reports.


Assuntos
Colite Ulcerativa/imunologia , Doença de Crohn/imunologia , Imunidade nas Mucosas , Imunoglobulina G/sangue , Mucosa Intestinal/imunologia , Animais , Biomarcadores/sangue , Sequência de Carboidratos , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Doença de Crohn/diagnóstico , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Modelos Animais de Doenças , Galectinas/química , Galectinas/imunologia , Galectinas/metabolismo , Glicosilação , Glicosiltransferases/imunologia , Glicosiltransferases/metabolismo , Humanos , Imunoglobulina G/química , Camundongos
15.
J Gastroenterol ; 51(4): 357-69, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26349931

RESUMO

BACKGROUND: Oligosaccharide structures and their alterations have important roles in modulating intestinal inflammation. N-Acetylglucosaminyltransferase V (GnT-V) is involved in the biosynthesis of N-acetylglucosamine (GlcNAc) by ß1,6-branching on N-glycans and is induced in various pathologic processes, such as inflammation and regeneration. GnT-V alters host immune responses by inhibiting the functions of CD4(+) T cells and macrophages. The present study aimed to clarify the role of GnT-V in intestinal inflammation using GnT-V transgenic mice. METHODS: Colitis severity was compared between GnT-V transgenic mice and wild-type mice. ß1,6-GlcNAc levels were investigated by phytohemagglutinin-L4 lectin blotting and flow cytometry. We investigated phagocytosis of macrophages by measuring the number of peritoneal-macrophage-ingested fluorescent latex beads by flow cytometry. Cytokine production in the culture supernatant of mononuclear cells from the spleen, mesenteric lymph nodes, and bone-marrow-derived macrophages was determined by enzyme-linked immunosorbent assay. Clodronate liposomes were intravenously injected to deplete macrophages in vivo. Chronic-colitis-associated tumorigenesis was assessed after 9 months of repeated administration of dextran sodium sulfate (DSS). RESULTS: DSS-induced colitis and colitis induced by trinitrobenzene sulfonic acid were markedly exacerbated in GnT-V transgenic mice compared with wild-type mice. Production of interleukin-10 and phagocytosis of macrophages were significantly impaired in GnT-V transgenic mice compared with wild-type mice. Clodronate liposome treatment to deplete macrophages blocked the exacerbation of DSS-induced colitis and impairment of interleukin-10 production in GnT-V transgenic mice. Chronic-colitis-associated tumorigenesis was significantly increased in GnT-V transgenic mice. CONCLUSIONS: Overexpression of GnT-V exacerbated murine experimental colitis by inducing macrophage dysfunction, thereby enhancing colorectal tumorigenesis.


Assuntos
Colite/patologia , Neoplasias do Colo/patologia , Macrófagos/patologia , N-Acetilglucosaminiltransferases/genética , Animais , Ácido Clodrônico/farmacologia , Colite/genética , Neoplasias do Colo/genética , Citocinas/metabolismo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Citometria de Fluxo , Inflamação/genética , Inflamação/patologia , Interleucina-10/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Índice de Gravidade de Doença , Ácido Trinitrobenzenossulfônico/toxicidade
16.
J Gastroenterol ; 51(4): 346-56, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26314836

RESUMO

BACKGROUND: Patients with inflammatory bowel disease (IBD) often exhibit vitamin K deficiency. Vitamin K has been shown to inhibit inflammation via interleukin (IL)-6 suppression. This study aimed to evaluate the effect of vitamin K in a murine model of colitis. METHODS: Colitis was induced using dextran sulfate sodium (DSS) in mice fed either a vitamin K-deficient (K-def) or a vitamin K-supplemented (K-sup) diet. The clinical and histological severity of colitis was assessed, and levels of cytokine production from the spleen and colonic lamina propria were measured by enzyme-linked immunosorbent assay and quantitative real-time reverse transcription polymerase chain reaction. Cytokine expression levels in CD4(+), CD11b(+), and CD19(+) cells in the presence and absence of vitamin K [menatetrenone (MK-4)] were measured in vitro and apoptosis was determined by caspase 3/7 activity and Annexin V staining. RESULTS: DSS administration resulted in significantly more severe body weight loss, shorter colon length, and higher histological scores in mice fed a K-def diet than those fed a K-sup diet. IL-6 expression in lamina propria mononuclear cells was significantly higher in the K-def group than in the K-sup group. IL-6 expression was significantly decreased in the presence of MK-4 in CD19(+) cells, but not in the CD4(+) and CD11b(+) subpopulations. Apoptotic cell population in CD19(+) cells was increased in the presence of MK-4 in vitro and in vivo. CONCLUSIONS: Vitamin K exerts a protective effect against DSS colitis; this effect is associated with IL-6 downregulation. Vitamin K could be a potential treatment target for IBD.


Assuntos
Colite/patologia , Inflamação/patologia , Deficiência de Vitamina K/complicações , Animais , Apoptose , Colite/etiologia , Citocinas/metabolismo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Inflamação/etiologia , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Índice de Gravidade de Doença
17.
World J Gastroenterol ; 22(17): 4403-10, 2016 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-27158210

RESUMO

AIM: To determine the efficacy of Mac-2 binding protein (Mac-2bp) for diagnosis of chronic pancreatitis. METHODS: Fifty-nine healthy volunteers (HV), 162 patients with chronic pancreatitis (CP), and 94 patients with pancreatic ductal adenocarcinoma (PDAC) were enrolled in this study. We measured serum Mac-2bp using our developed enzyme-linked immunosorbent assay kit. Additional biochemical variables were measured using an automated analyzer (including aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, triglyceride, C-reactive protein, and amylase levels) or chemiluminescent enzyme immunoassay (carbohydrate antigen 19-9 and carcinoembryonic antigen). The ability of Mac-2bp to predict CP diagnosis accurately was assessed using receiver operating characteristic (ROC) analyses. RESULTS: Serum Mac-2bp levels were significantly increased in CP patients compared to HV (P < 0.0001) and PDAC patients (P < 0.0001). Area under the ROC curve values of Mac-2bp for the discrimination of CP from HV and PDAC were 0.727 and 0.784, respectively. Multivariate analyses demonstrated that serum Mac-2bp levels were independent determinants for CP diagnosis from HV and PDAC patients. Immunohistological staining showed that Mac-2bp was expressed faintly in the pancreas tissues of both CP and PDAC patients. Serum aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, and triglyceride levels were significantly higher in patients with CP or PDAC. Serum Mac-2bp levels were highly correlated with protein levels of alanine aminotransferase, γ-glutamyltransferase, and C-reactive protein, but not amylase, suggesting that the damaged liver produces Mac-2bp. CONCLUSION: Measurement of serum Mac-2bp may be a novel and useful biomarker for CP diagnosis as well as liver fibrosis in the general population.


Assuntos
Antígenos de Neoplasias/sangue , Biomarcadores/sangue , Glicoproteínas de Membrana/sangue , Pancreatite Crônica/diagnóstico , Adulto , Idoso , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Proteína C-Reativa/análise , Carcinoma Ductal Pancreático/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/sangue , Pancreatite Crônica/sangue
18.
J Phys Chem B ; 109(15): 7188-94, 2005 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16851820

RESUMO

We examined the catalytic effect of nanoparticle 3d-transition metals on hydrogen desorption (HD) properties of MgH(2) prepared by mechanical ball milling method. All the MgH(2) composites prepared by adding a small amount of nanoparticle Fe(nano), Co(nano), Ni(nano), and Cu(nano) metals and by ball milling for 2 h showed much better HD properties than the pure ball-milled MgH(2) itself. In particular, the 2 mol % Ni(nano)-doped MgH(2) composite prepared by soft milling for a short milling time of 15 min under a slow milling revolution speed of 200 rpm shows the most superior hydrogen storage properties: A large amount of hydrogen ( approximately 6.5 wt %) is desorbed in the temperature range from 150 to 250 degrees C at a heating rate of 5 degrees C/min under He gas flow with no partial pressure of hydrogen. The EDX micrographs corresponding to Mg and Ni elemental profiles indicated that nanoparticle Ni metals as catalyst homogeneously dispersed on the surface of MgH(2). In addition, it was confirmed that the product revealed good reversible hydriding/dehydriding cycles even at 150 degrees C. The hydrogen desorption kinetics of catalyzed and noncatalyzed MgH(2) could be understood by a modified first-order reaction model, in which the surface condition was taken into account.

19.
J Phys Chem B ; 109(31): 14855-8, 2005 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-16852881

RESUMO

The hydrogen desorption mechanism in the reaction from LiH + LiNH2 to Li2NH + H2 was examined by thermal desorption mass spectrometry, thermogravimetric analysis, and Fourier transform IR analyses for the products replaced by LiD or LiND2 for LiH or LiNH2, respectively. The results obtained indicate that the hydrogen desorption reaction proceeds through the following two-step elementary reactions mediated by ammonia: 2LiNH2 --> Li2NH + NH3 and LiH + NH3 --> LiNH2 + H2, where hydrogen molecules are randomly formed from four equivalent hydrogen atoms in a hypothetical LiNH4 produced by the reaction between LiH and NH3 according to the laws of probability.

20.
J Phys Chem B ; 109(21): 10744-8, 2005 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-16852305

RESUMO

The Li-Mg-N-H system composed of 3 Mg(NH2)2 and 8 LiH reversibly desorbs/absorbs approximately 7 wt % of H2 at 120-200 degrees C and transforms into 4 Li2NH and Mg3N2 after dehydrogenation. In this work, the mechanism of the hydrogenation reaction from 4 Li2NH and Mg3N2 to 8 LiH and 3 Mg(NH2)2 was investigated in detail. Experimental results indicate that 4 Li2NH is first hydrogenated into 4 LiH and 4 LiNH2. At the next step, 4 LiNH2 decomposes into 2 Li2NH and 2 NH3, and the emitted 2 NH3 reacts with (1/2) Mg3N2 and produces the (3/2) Mg(NH2)2 phase, while the produced 2 Li2NH is hydrogenated into 2 LiH and 2 LiNH2 again. Such successive steps continue until all 4 Li2NH and Mg3N2 completely transform into 8 LiH and 3 Mg(NH2)2 by hydrogenation.

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