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1.
Clin J Gastroenterol ; 16(4): 593-598, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37040045

RESUMEN

Hepatic portal vein gas (HPVG) is caused by the influx of gastrointestinal gas into the intrahepatic portal vein as a result of gastrointestinal wall fragility due to ischemia or necrosis. Gastrointestinal tract necrosis is fatal in severe cases. We observed a case of food intake-induced acute gastric dilatation (AGD) in a healthy young male who developed HPVG and underwent conservative treatment. A 25-year-old male presented to our hospital with epigastric pain and nausea the day after excessive food intake. Computed tomography (CT) revealed gas along the intrahepatic portal vein and marked gastric dilatation with large food residue. AGD-induced HPVG was considered. Esophagogastroduodenoscopy (EGD) was not performed at this stage because of the risk of HPVG and AGD exacerbation, and the patient was followed up with intragastric decompression via a nasogastric tube. Food residue and approximately 2 L of liquid without blood were vomited 1 h after the nasogastric tube placement. His symptoms improved after the vomiting episode. An EGD was performed 2 days after undergoing CT. Endoscopic findings revealed extensive erosions and the presence of a whitish coat extending from the fornix to the lower body of the stomach, indicating AGD. HPVG disappeared on the CT scan taken during EGD. Thereafter, symptom relapse and HPVG recurrence were not observed.


Asunto(s)
Dilatación Gástrica , Vena Porta , Humanos , Masculino , Adulto , Vena Porta/diagnóstico por imagen , Dilatación Gástrica/diagnóstico por imagen , Dilatación Gástrica/etiología , Tomografía Computarizada por Rayos X , Necrosis
2.
Lab Invest ; 103(3): 100025, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36925201

RESUMEN

Although platinum-combination chemotherapy shows a high response rate at the primary site, epithelial ovarian cancer (EOC) treatment remains challenging because of tumor recurrence and metastasis. Recent studies have revealed that chemotherapy paradoxically promotes cancer cell survival, proliferation, and metastasis, although the reason for this remains unclear. The underlying molecular mechanisms that contribute to chemotherapy-induced metastasis need to be elucidated to establish effective therapeutic strategies. Acute kidney injury is a known side effect of cisplatin treatment, and kidney dysfunction results in the accumulation of uremic toxins in the serum. The present study aimed to investigate whether indoxyl sulfate (IS), a representative uremic toxin, affects the pathophysiology of EOC. In this study, IS reduced the expression of Mas receptor (MasR) in cultured human EOC cells. Both knockdown of the aryl hydrocarbon receptor (AhR), which is an intracellular IS receptor, and inhibition of AhR function suppressed IS-mediated downregulation of MasR in SK-OV-3 cells. IS induced the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in an AhR-dependent manner. Inhibition of the STAT3 pathway or reactive oxygen species production suppressed the IS-mediated reduction of MasR. IS stimulated cell migration and invasion of SK-OV-3 cells in an AhR-dependent manner. Cisplatin-nephropathy model mice exhibited elevated levels of serum IS accompanied by elevated levels of blood urea nitrogen and serum creatinine. Furthermore, intraperitoneal administration of IS in mice promoted tumor growth and metastasis. Finally, we found that the MasR agonist Ang-(1-7) suppressed the IS-mediated effects on cell proliferation, migration, and invasion of SK-OV-3 cells. However, the knockdown of MasR expression by specific small interfering RNA in the absence of IS resulted in only minimal promotion of cell migration and invasion. These findings demonstrate that IS promotes malignancy in ovarian cancer via AhR-mediated downregulation of MasR function, whereas Ang-(1-7) attenuates this effect, thereby suggesting that Ang-(1-7) could provide a future treatment strategy for this cancer type.


Asunto(s)
Indicán , Neoplasias Ováricas , Ratones , Humanos , Animales , Femenino , Indicán/farmacología , Indicán/metabolismo , Regulación hacia Abajo , Receptores de Hidrocarburo de Aril/metabolismo , Cisplatino/farmacología
3.
Cancer Sci ; 111(5): 1794-1804, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32154964

RESUMEN

Folate receptor alpha (FRα) is overexpressed in >80% of epithelial ovarian cancer (EOC). Accordingly, folate is attracting attention as a targeting ligand for EOC. For EOC patients, paclitaxel (PTX) is generally used as a first-line chemotherapeutic agent in combination with platinum-based drugs. Cyclodextrin (CyD) is a potential new formulation vehicle for PTX that could replace Cremophor-EL, a traditional formulation vehicle that causes significant side effects, including neutropenia. Several years ago, folate-appended ß-CyD (Fol-c1 -ß-CyD) was developed as an FRα-targeting drug carrier, but its efficacy as a treatment for EOC remains to be determined. In this study, we assessed the antitumor activity of PTX in Fol-c1 -ß-CyD (PTX/Fol-c1 -ß-CyD) in EOC-derived cell lines. We found that PTX/Fol-c1 -ß-CyD killed not only FRα-expressing cells but also FRα-negative cells. In the FRα-negative A2780 cells, knockdown of proton-coupled folate transporter (PCFT) significantly decreased the cytotoxicity of PTX/Fol-c1 -ß-CyD, whereas knockdown of FRα did not. By contrast, knockdown of either FRα or proton-coupled folate transporter (PCFT) decreased the cytotoxicity of PTX/Fol-c1 -ß-CyD in FRα-expressing SK-OV-3 cells. Furthermore, the cytotoxicity of PTX/Fol-c1 -ß-CyD in A2780 cells was increased at acidic pH, and this increase was suppressed by PCFT inhibitor. In mice intraperitoneally inoculated with FRα-expressing or PCFT-expressing EOC cells, intraperitoneal administration of PTX/Fol-c1 -ß-CyD significantly suppressed the growth of both types of EOC cells relative to PTX alone, without inducing a significant change in the neutrophil/white blood cell ratio. Our data suggest that Fol-c1 -ß-CyD targets not only FRα but also PCFT, and can efficiently deliver anticancer drugs to EOC cells in the peritoneal cavity.


Asunto(s)
Carcinoma Epitelial de Ovario/metabolismo , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Ácido Fólico/química , Neoplasias Ováricas/metabolismo , Transportador de Folato Acoplado a Protón/metabolismo , beta-Ciclodextrinas/química , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Antineoplásicos/farmacología , Carcinoma Epitelial de Ovario/tratamiento farmacológico , Carcinoma Epitelial de Ovario/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/administración & dosificación , Femenino , Receptor 1 de Folato/genética , Receptor 1 de Folato/metabolismo , Ácido Fólico/administración & dosificación , Expresión Génica , Humanos , Ratones , Estructura Molecular , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Paclitaxel/administración & dosificación , Paclitaxel/química , Paclitaxel/farmacología , Transportador de Folato Acoplado a Protón/genética , Ensayos Antitumor por Modelo de Xenoinjerto , beta-Ciclodextrinas/administración & dosificación
4.
J Am Chem Soc ; 141(43): 17042-17047, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31523958

RESUMEN

The metal-catalyzed (Z)-selective hydroboration of terminal alkynes is synthetically challenging due to the usually (E)-selective nature of the hydroboration and the formation of the thermodynamically unstable (Z)-isomer. Herein, we report that N-heterocyclic-carbene-ligated ruthenium complexes catalyze the (Z)-selective hydroboration of terminal alkynes with H-B(dan) (dan = naphthalene-1,8-diaminato), which generates a diverse range of synthetically valuable (Z)-alkenylboranes. Mechanistic studies, particularly the isolation of a catalytically relevant borylruthenium complex, revealed a mechanism that involves the insertion of the alkyne into a Ru-B bond, which provides a catalytic cycle that is distinctly different from that of previously reported (Z)-selective hydroborations. The direct cross-coupling of the obtained (Z)-alkenyl-B(dan) enables the rapid synthesis of biologically active Combretastatin A-4 analogues.


Asunto(s)
Alquinos/química , Boro/química , Rutenio/química , Estilbenos/química , Alquinos/síntesis química , Antineoplásicos Fitogénicos/síntesis química , Isomerismo , Metano/análogos & derivados , Metano/química , Estructura Molecular , Naftalenos/química , Estilbenos/síntesis química
5.
Org Lett ; 19(19): 5204-5207, 2017 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-28885855

RESUMEN

The N-heterocyclic-carbene-ligated ruthenium complex [RuHCl(CO)(H2IMes)(PCy3)] exhibits high catalytic activity for the (Z)-selective hydrosilylation of various terminal alkynes with 1,1,1,3,5,5,5-heptamethyltrisiloxane (HSiMe(OSiMe3)2). The stereoretentive derivatization of the (Z)-alkenylsiloxanes allows the synthesis of biologically active compounds, e.g. potent antitumor agents and inhibitors for induced-NO synthase.

6.
Biochem Biophys Res Commun ; 489(2): 248-254, 2017 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-28559134

RESUMEN

Orally administered Lactobacillus strains, including L. plantarum No.14 and L. rhamnosus GG, reportedly reduce inflammatory cytokine production in mice. The present study tested our idea that circulating exosomes mediate the action of Lactobacillus strains. The lipopolysaccharide-induced production of TNF-α and IL-6 in vitro was attenuated in peritoneal exudate cells (PECs) isolated from C57BL/6N mice that had been fed L. plantarum No.14. When PECs were cultured for 24 h with exosomes isolated from the serum of mice fed L. plantarum No.14 or L. rhamnosus GG, accumulation of both TNF-α and of the corresponding mRNA was lowered. Growth in the presence of these exosomes also decreased the production of TNF-α and IL-6 by the murine macrophage cell line RAW264.7. In contrast, supplementation with exosome-depleted serum of mice fed L. plantarum No.14 or L. rhamnosus GG failed to affect the production of TNF-α and IL-6 by RAW264.7 cells. When PECs and RAW264.7 cells were cultured for 24 h with PKH67-labeled exosomes isolated from murine serum, fluorescent signal was observed inside the cells, suggesting that these cells incorporate serum exosomes. We propose that the anti-inflammatory activity of orally administered L. plantarum No.14 and L. rhamnosus GG is mediated, at least in part, by circulating exosomes.


Asunto(s)
Citocinas/biosíntesis , Exosomas/microbiología , Inflamación/metabolismo , Lactobacillus/inmunología , Macrófagos/metabolismo , Administración Oral , Animales , Células Cultivadas , Exosomas/inmunología , Femenino , Inflamación/inmunología , Lactobacillus/clasificación , Lipopolisacáridos/administración & dosificación , Lipopolisacáridos/farmacología , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , Células RAW 264.7
7.
Nephron Exp Nephrol ; 128(1-2): 1-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25376195

RESUMEN

BACKGROUND/AIMS: Interleukin-6 (IL-6) is one of the inflammation biomarkers with highest predictive value for outcome in chronic kidney disease (CKD) patients. The present study aimed to determine the effects of indoxyl sulfate (IS) on IL-6 expression in vascular cells. METHODS: IS was administered to normo- and hypertensive rats. Human umbilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs) were incubated with or without IS. RESULTS: Immunohistochemistry revealed that IS-administered rats showed increased expression of IL-6 in the aortic tissues. IS increased IL-6 expression in HUVECs and HASMCs in a time- and dose-dependent manner. Knockdown of organic anion transporter 3 (OAT3) using small interfering RNA (siRNA) inhibited IS-induced expression of IL-6 in HUVECs and HASMCs. IS induced activation of aryl hydrocarbon receptor (AhR) and nuclear factor-κB (NF-κB) subunit p65 in HUVECs and HASMCs. Both AhR siRNA and p65 siRNA inhibited IS-induced expression of IL-6. AhR siRNA inhibited IS-induced phosphorylation and nuclear translocation of p65 without change in total p65 level. However, p65 siRNA did not inhibit IS-induced nuclear translocation of AhR. Thus, AhR is responsible for IS-induced p65 signaling transduction. CONCLUSION: IS induces IL-6 expression in vascular endothelial and smooth muscle cells through OAT3/AhR/NF-κB pathway.


Asunto(s)
Endotelio Vascular/metabolismo , Indicán/farmacología , Interleucina-6/metabolismo , Músculo Liso Vascular/metabolismo , FN-kappa B/metabolismo , Transportadores de Anión Orgánico Sodio-Independiente/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Humanos , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , Transportadores de Anión Orgánico Sodio-Independiente/efectos de los fármacos , Transportadores de Anión Orgánico Sodio-Independiente/genética , ARN Interferente Pequeño/farmacología , Ratas , Ratas Endogámicas Dahl , Transducción de Señal/fisiología , Factores de Tiempo , eIF-2 Quinasa/metabolismo
8.
PLoS One ; 9(3): e91517, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24614509

RESUMEN

UNLABELLED: Renin-angiotensin system (RAS) plays a pivotal role in chronic kidney disease (CKD). Angiotensin converting enzyme-related carboxypeptidase 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor axis counteracts the deleterious actions of Ang II. ACE2 exerts its actions by cleaving Ang II into Ang-(1-7) which activates Mas receptor. This study aimed to determine if the expression of Mas receptor is altered in the kidneys of CKD rats, and if indoxyl sulfate (IS), a uremic toxin, affects the expression of Mas receptor in rat kidneys and cultured human proximal tubular cells (HK-2 cells). The expression of Mas receptor was examined in the kidneys of CKD and AST-120-treated CKD rats using immunohistochemistry. Further, the effects of IS on Mas receptor expression in the kidneys of normotensive and hypertensive rats were examined. The effects of IS on the expression of Mas receptor and phosphorylation of endothelial nitric oxide synthase (eNOS) in HK-2 cells were examined using immunoblotting. CKD rats showed reduced renal expression of Mas receptor, while AST-120 restored its expression. Administration of IS downregulated Mas receptor expression in the kidneys of normotensive and hypertensive rats. IS downregulated Mas receptor expression in HK-2 cells in a time- and dose-dependent manner. Knockdown of organic anion transporter 3 (OAT3), aryl hydrocarbon receptor (AhR), and signal transducer and activator of transcription 3 (Stat3) inhibited IS-induced downregulation of Mas receptor and phosphorylated eNOS. N-acetylcysteine, an antioxidant, also inhibited IS-induced downregulation of Mas receptor and phosphorylated eNOS. Ang-(1-7) attenuated IS-induced transforming growth factor-ß1 (TGF-ß1) expression. CONCLUSION: Mas receptor expression is reduced in the kidneys of CKD rats. IS downregulates renal expression of Mas receptor via OAT3/AhR/Stat3 pathway in proximal tubular cells. IS-induced downregulation of Mas receptor might be involved in upregulation of TGF-ß1 in proximal tubular cells.


Asunto(s)
Regulación hacia Abajo/efectos de los fármacos , Indicán/farmacología , Túbulos Renales Proximales/metabolismo , Transportadores de Anión Orgánico Sodio-Independiente/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Factor de Transcripción STAT3/metabolismo , Acetilcisteína/farmacología , Angiotensinas/farmacología , Animales , Humanos , Inmunohistoquímica , Indicán/administración & dosificación , Túbulos Renales Proximales/citología , Túbulos Renales Proximales/efectos de los fármacos , Masculino , Modelos Biológicos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosforilación/efectos de los fármacos , Proto-Oncogenes Mas , ARN Interferente Pequeño/metabolismo , Ratas Endogámicas Dahl , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Insuficiencia Renal Crónica/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Factor de Crecimiento Transformador beta1/metabolismo
9.
J Am Chem Soc ; 135(39): 14508-11, 2013 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-24044752

RESUMEN

A density functional theory (DFT) study was performed to elucidate the mechanism of the Ni-catalyzed [3 + 2 + 2] cyclization reaction of cyclopropylideneacetate with two alkynes. A systematic search showed that the nature of the alkynes determines the choice between two reaction pathways and hence the regioselectivity. Strongly electron-deficient acetylenes preferentially afford 2,5-disubstituted products via nickelacyclopentadienes generated by [2 + 2] cocyclization, whereas normal alkynes afford 3,4- or 3,5-products via an unprecedented pathway involving a [3 + 2] nickelacycle intermediate.


Asunto(s)
Acetatos/química , Alquinos/química , Ciclopropanos/química , Níquel/química , Estereoisomerismo
10.
J Virol ; 87(11): 6482-91, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23552409

RESUMEN

Epstein-Barr virus (EBV) replication proteins are transported into the nucleus to synthesize viral genomes. We here report molecular mechanisms for nuclear transport of EBV DNA polymerase. The EBV DNA polymerase catalytic subunit BALF5 was found to accumulate in the cytoplasm when expressed alone, while the EBV DNA polymerase processivity factor BMRF1 moved into the nucleus by itself. Coexpression of both proteins, however, resulted in efficient nuclear transport of BALF5. Deletion of the nuclear localization signal of BMRF1 diminished the proteins' nuclear transport, although both proteins can still interact. These results suggest that BALF5 interacts with BMRF1 to effect transport into the nucleus. Interestingly, we found that Hsp90 inhibitors or knockdown of Hsp90ß with short hairpin RNA prevented the BALF5 nuclear transport, even in the presence of BMRF1, both in transfection assays and in the context of lytic replication. Immunoprecipitation analyses suggested that the molecular chaperone Hsp90 interacts with BALF5. Treatment with Hsp90 inhibitors blocked viral DNA replication almost completely during lytic infection, and knockdown of Hsp90ß reduced viral genome synthesis. Collectively, we speculate that Hsp90 interacts with BALF5 in the cytoplasm to assist complex formation with BMRF1, leading to nuclear transport. Hsp90 inhibitors may be useful for therapy for EBV-associated diseases in the future.


Asunto(s)
Antígenos Virales/metabolismo , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , ADN Polimerasa Dirigida por ADN/metabolismo , Infecciones por Virus de Epstein-Barr/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Herpesvirus Humano 4/enzimología , Proteínas Virales/metabolismo , Transporte Activo de Núcleo Celular , Antígenos Virales/genética , Núcleo Celular/genética , Núcleo Celular/virología , Proteínas de Unión al ADN/genética , ADN Polimerasa Dirigida por ADN/genética , Infecciones por Virus de Epstein-Barr/virología , Proteínas HSP90 de Choque Térmico/genética , Células HeLa , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Humanos , Unión Proteica , Proteínas Virales/genética
11.
J Virol ; 87(7): 4060-70, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23365429

RESUMEN

Epstein-Barr virus (EBV), a human oncogenic herpesvirus that establishes a lifelong latent infection in the host, occasionally enters lytic infection to produce progeny viruses. The EBV oncogene latent membrane protein 1 (LMP1), which is expressed in both latent and lytic infection, constitutively activates the canonical NF-κB (p65) pathway. Such LMP1-mediated NF-κB activation is necessary for proliferation of latently infected cells and inhibition of viral lytic cycle progression. Actually, canonical NF-κB target gene expression was suppressed upon the onset of lytic infection. TRAF6, which is activated by conjugation of polyubiquitin chains, associates with LMP1 to mediate NF-κB signal transduction. We have found that EBV-encoded BPLF1 interacts with and deubiquitinates TRAF6 to inhibit NF-κB signaling during lytic infection. HEK293 cells with BPLF1-deficient recombinant EBV exhibited poor viral DNA replication compared with the wild type. Furthermore, exogenous expression of BPLF1 or p65 knockdown in cells restored DNA replication of BPLF1-deficient viruses, indicating that EBV BPLF1 deubiquitinates TRAF6 to inhibit NF-κB signal transduction, leading to promotion of viral lytic DNA replication.


Asunto(s)
Herpesvirus Humano 4/enzimología , FN-kappa B/metabolismo , Transducción de Señal/fisiología , Factor 6 Asociado a Receptor de TNF/metabolismo , Proteínas de la Matriz Viral/metabolismo , Proteínas Reguladoras y Accesorias Virales/metabolismo , Replicación Viral/fisiología , Análisis de Varianza , Cromosomas Artificiales Bacterianos , Cartilla de ADN/genética , Células HEK293 , Herpesvirus Humano 4/fisiología , Humanos , Immunoblotting , Inmunoprecipitación , Luciferasas , Mutagénesis , Reacción en Cadena en Tiempo Real de la Polimerasa , Transfección , Ubiquitinación
12.
Circ J ; 77(5): 1326-36, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23337206

RESUMEN

BACKGROUND: Erythropoietin (EPO) is used to treat anemia in patients with chronic kidney disease (CKD). A wide variation in individual response to EPO, however, is often observed, causing EPO resistance. EPO exhibits not only hematopoietic but also extra-hematopoietic functions such as endothelial effects. Indoxyl sulfate, a uremic toxin, is involved in endothelial dysfunction, and consequently, the pathogenesis of CKD-associated cardiovascular disease. The aim of the present study was to determine the effect of indoxyl sulfate on the extra-hematopoietic functions of EPO in human umbilical vein endothelial cells (HUVECs). METHODS AND RESULTS: HUVECs were incubated with or without indoxyl sulfate or an Akt inhibitor, and then stimulated with or without EPO. Indoxyl sulfate suppressed EPO-induced survival/proliferation, anti-apoptosis function, phosphorylation of endothelial nitric oxide synthase, and the expression of thrombospondin-1, an erythroid-stimulating factor, in HUVECs. Although EPO induced phosphorylation of both Akt and extracellular signal-regulated kinases (ERK) in HUVECs, indoxyl sulfate suppressed phosphorylation of Akt but not ERK. An Akt kinase inhibitor or Akt small interfering RNA suppressed all the EPO-induced cellular effects in HUVECs. As a site of action of indoxyl sulfate on EPO signaling, indoxyl sulfate attenuated EPO-induced tyrosine phosphorylation of EPO receptor (EPOR) in HUVECs. CONCLUSIONS: Indoxyl sulfate negatively regulates the EPOR-Akt pathway in endothelial cells, and might contribute to EPO resistance and endothelial dysfunction in patients with CKD.


Asunto(s)
Eritropoyetina/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Indicán/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Células Endoteliales de la Vena Umbilical Humana/enzimología , Humanos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/genética , Interferencia de ARN , Receptores de Eritropoyetina/efectos de los fármacos , Receptores de Eritropoyetina/metabolismo , Transducción de Señal/efectos de los fármacos , Trombospondina 1/metabolismo , Factores de Tiempo , Transfección
13.
J Virol ; 86(9): 4752-61, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22357272

RESUMEN

The Epstein-Barr virus (EBV) predominantly establishes latent infection in B cells, and the reactivation of the virus from latency is dependent on the expression of the viral BZLF1 protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers, such as 12-O-tetradecanoylphorbol-13-acetate (TPA), calcium ionophores, or histone deacetylase (HDAC) inhibitors. In some cell lines latently infected with EBV, an HDAC inhibitor alone can induce BZLF1 transcription, while the treatment does not enhance expression in other cell lines, such as B95-8 or Raji cells, suggesting unknown suppressive mechanisms besides histone deacetylation in those cells. Here, we found the epigenetic modification of the BZLF1 promoter in latent Raji cells by histone H3 lysine 27 trimethylation (H3K27me3), H3K9me2/me3, and H4K20me3. Levels of active markers such as histone acetylation and H3K4me3 were low in latent cells but increased upon reactivation. Treatment with 3-deazaneplanocin A (DZNep), an inhibitor of H3K27me3 and H4K20me3, significantly enhanced the BZLF1 transcription in Raji cells when in combination with an HDAC inhibitor, trichostatin A (TSA). The knockdown of Ezh2 or Suv420h1, histone methyltransferases for H3K27me3 or H4K20me3, respectively, further proved the suppression of Zp by the methylations. Taken together, the results indicate that H3K27 methylation and H4K20 methylation are involved, at least partly, in the maintenance of latency, and histone acetylation and H3K4 methylation correlate with the reactivation of the virus in Raji cells.


Asunto(s)
Epigénesis Genética , Herpesvirus Humano 4/genética , Histonas/metabolismo , Regiones Promotoras Genéticas , Transactivadores/genética , Latencia del Virus/genética , Azacitidina/análogos & derivados , Azacitidina/farmacología , Línea Celular , Metilasas de Modificación del ADN/antagonistas & inhibidores , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Decitabina , Proteína Potenciadora del Homólogo Zeste 2 , Regulación Viral de la Expresión Génica/efectos de los fármacos , Silenciador del Gen , Inhibidores de Histona Desacetilasas/farmacología , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Complejo Represivo Polycomb 2 , Regiones Promotoras Genéticas/efectos de los fármacos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
14.
J Biol Chem ; 286(49): 42524-42533, 2011 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-22013073

RESUMEN

Epstein-Barr virus LMP1, a major oncoprotein expressed in latent infection, is critical for primary B cell transformation, functioning as a TNFR family member by aggregation in the plasma membrane resulting in constitutive activation of cellular signals, such as NF-κB, MAPK, JAK/STAT, and AKT. Although transcription of LMP1 in latent type III cells is generally under the control of the viral coactivator EBNA2, little is known about EBNA2-independent LMP1 expression in type II latency. We thus screened a cDNA library for factors that can activate the LMP1 promoter in an EBNA2-independent manner, using a reporter assay system. So far, we have screened >20,000 clones, and here identified C/EBPε as a new transcriptional activator. Exogenous expression of C/EBPα, -ß, or -ε efficiently augmented LMP1 mRNA and protein levels in EBV-positive cell lines, whereas other members of the C/EBP family exhibited modest or little activity. It has been demonstrated that LMP1 gene transcription depends on two promoter regions: proximal (ED-L1) and distal (TR-L1). Interestingly, although we first used the proximal promoter for screening, we found that C/EBP increased transcription from both promoters in latent EBV-positive cells. Mutagenesis in reporter assays and EMSA identified only one functional C/EBP binding site, through which activation of both proximal and distal promoters is mediated. Introduction of point mutations into the identified C/EBP site in EBV-BAC caused reduced LMP1 transcription from both LMP1 promoters in epithelial cells. In conclusion, C/EBP is a newly identified transcriptional activator of the LMP1 gene, independent of the EBNA2 coactivator.


Asunto(s)
Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Regulación de la Expresión Génica , Activación Transcripcional , Proteínas de la Matriz Viral/genética , Secuencias de Aminoácidos , Sitios de Unión , Línea Celular , Biblioteca de Genes , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Células HeLa , Humanos , Modelos Genéticos , Oncogenes , Regiones Promotoras Genéticas , ARN Mensajero/metabolismo , Transcripción Genética
15.
J Biol Chem ; 286(25): 22007-16, 2011 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-21525011

RESUMEN

Reactivation of the Epstein-Barr virus from latency is dependent on expression of the BZLF1 viral immediate-early protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical inducers such as 12-O-tetradecanoylphorbol-13-acetate and calcium ionophore. We found that Jun dimerization protein 2 (JDP2) plays a significant role in suppressing Zp activity. Reporter, EMSA, and ChIP assays of a Zp mutant virus revealed JDP2 association with Zp at the ZII cis-element, a binding site for CREB/ATF/AP-1. Suppression of Zp activity by JDP2 correlated with HDAC3 association and reduced levels of histone acetylation. Although introduction of point mutations into the ZII element of the viral genome did not increase the level of BZLF1 production, silencing of endogenous JDP2 gene expression by RNA interference increased the levels of viral early gene products and viral DNA replication. These results indicate that JDP2 plays a role as a repressor of Zp and that its replacement by CREB/ATF/AP-1 at ZII is crucial to triggering reactivation from latency to lytic replication.


Asunto(s)
Herpesvirus Humano 4/fisiología , Proteínas Represoras/metabolismo , Latencia del Virus , Silenciador del Gen , Células HEK293 , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Histona Desacetilasas/metabolismo , Humanos , Regiones Promotoras Genéticas/genética , Proteínas Represoras/deficiencia , Proteínas Represoras/genética , Transactivadores/genética , Transcripción Genética , Activación Viral
16.
J Virol ; 85(13): 6127-35, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21490093

RESUMEN

Productive replication of Epstein-Barr virus occurs in discrete sites in nuclei, called replication compartments, where viral DNA replication proteins and host homologous recombinational repair (HRR) and mismatch repair (MMR) factors are recruited. Three-dimensional (3D) surface reconstruction imaging clarified the spatial arrangements of these factors within the replication compartments. Subnuclear domains, designated BMRF1 cores, which were highly enriched in viral polymerase processivity factor BMRF1 could be identified inside the replication compartments. Pulse-chase experiments revealed that newly synthesized viral genomes organized around the BMRF1 cores were transferred inward. HRR factors could be demonstrated mainly outside BMRF1 cores, where de novo synthesis of viral DNA was ongoing, whereas MMR factors were found predominantly inside. These results imply that de novo synthesis of viral DNA is coupled with HRR outside the cores, followed by MMR inside cores for quality control of replicated viral genomes. Thus, our approach unveiled a viral genome manufacturing plant.


Asunto(s)
Reparación de la Incompatibilidad de ADN , Reparación del ADN , Herpesvirus Humano 4/metabolismo , Recombinación Genética , Replicación Viral , Animales , Línea Celular , Núcleo Celular/ultraestructura , Núcleo Celular/virología , Replicación del ADN , ADN Viral/genética , ADN Viral/metabolismo , Genoma Viral , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/ultraestructura , Humanos , Procesamiento de Imagen Asistido por Computador , Microscopía Confocal , Proteínas Virales/genética , Proteínas Virales/metabolismo
17.
Biotechnol Lett ; 33(1): 33-9, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20820878

RESUMEN

Bovine lactoferrin (BLF) enhanced production of hyaluronan in normal human dermal fibroblasts. The elevation of hyaluronan was accompanied by elevation of HAS2 (hyaluronan synthase 2) mRNA transcription and HAS2 protein expression. The promoting effect of BLF was not observed for HAS1. In addition, COL1A1 transcription and collagen synthesis were enhanced by BLF. These observations suggest that BLF promotes wound healing by increasing hyaluronan and type-I collagen synthesis.


Asunto(s)
Fibroblastos/metabolismo , Ácido Hialurónico/biosíntesis , Lactoferrina/metabolismo , Animales , Bovinos , Colágeno Tipo I/biosíntesis , Cadena alfa 1 del Colágeno Tipo I , Expresión Génica , Glucuronosiltransferasa/biosíntesis , Humanos , Hialuronano Sintasas , Regulación hacia Arriba , Cicatrización de Heridas
18.
J Hepatobiliary Pancreat Sci ; 17(5): 673-81, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20703846

RESUMEN

BACKGROUND: Accurate preoperative estimation of remnant liver function is critically important for hepatic surgery, and the expression of asialoglycoprotein receptors (ASGPR) is associated with hepatic function. METHODS: Thirty-two patients with hepatocellular carcinoma who underwent surgical resection were studied. To estimate the expression of ASGPR in the remnant liver, simulated surgery was performed on fusion images that combined data from (99m)technetium-galactosyl human serum albumin ((99m)Tc-GSA)/single photon emission computed tomography (SPECT) and computed tomography (CT) scanning. The liver uptake ratio (LUR) of (99m)Tc-GSA and the functional liver volume (FLV) in the remnant liver were predicted and were compared with postoperative liver function parameters. RESULTS: The LUR of (99m)Tc-GSA was strongly correlated with the extent of hepatic ASGPR expression (r = 0.944, p = 5.01 x 10(-16)), being confirmed to be a reliable parameter for the evaluation of liver function. The estimated remnant LUR, but not the estimated remnant FLV, was significantly correlated with postoperative liver function parameters, such as serum total bilirubin (r = -0.430, p < 0.05), prothrombin activity (r = 0.515, p < 0.01), and serum cholinesterase activity (r = 0.546, p < 0.01) at 1 week. CONCLUSION: Preoperative estimation of the extent of ASGPR expression in the remnant liver on CT/GSA-SPECT fusion images correlated well with postoperative liver function parameters, suggesting its usefulness for surgical decisions.


Asunto(s)
Receptor de Asialoglicoproteína/biosíntesis , Carcinoma Hepatocelular/diagnóstico , Hepatectomía/métodos , Neoplasias Hepáticas/diagnóstico , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Pentetato de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón Único/métodos , Tomografía Computarizada por Rayos X/métodos , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/cirugía , Femenino , Estudios de Seguimiento , Humanos , Hígado/diagnóstico por imagen , Hígado/metabolismo , Pruebas de Función Hepática , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Cuidados Preoperatorios , Radiofármacos/farmacocinética , Estudios Retrospectivos , Agregado de Albúmina Marcado con Tecnecio Tc 99m/farmacocinética , Pentetato de Tecnecio Tc 99m/farmacocinética
19.
J Org Chem ; 75(2): 480-3, 2010 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-20014802

RESUMEN

Heteroatom-substituted alkynes such as ynol ethers and ynamines turned out to be decent substrates for the Ni-catalyzed [3 + 2 + 2] cocyclization of ethyl cyclopropylideneacetate (1). The three-component cocyclization of 1, 1,3-diynes, and heteroatom-substituted alkynes also proceeded selectively. The study provided an efficient method for the synthesis of heteroatom-substituted cycloheptadiene and related compounds.

20.
J Hepatobiliary Pancreat Surg ; 16(6): 808-15, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19466379

RESUMEN

BACKGROUND/PURPOSE: Laparoscopic liver resection has not gained wide acceptance compared with other laparoscopic procedures. We evaluated the impact of simulated surgery using data from multidetector CT scanning on planning for laparoscopic hepatectomy. METHODS: The hepatectomy simulation system was programmed to perform three-dimensional reconstruction of the vasculature and to calculate the liver resection volume and surgical margin. In 35 patients undergoing laparoscopic hepatectomy or laparoscopy-assisted hepatectomy, the liver resection volume and margin were estimated by simulation preoperatively. Then, the estimated values were compared with the actual resected liver weight and margin. RESULTS: Three-dimensional reconstruction allowed stereoscopic identification of the tumor-bearing portal vein and draining vein. The predicted liver resection volume and margin both showed a significant correlation with the actual values: the mean difference was 21 mL (P < 0.0001) and 1.3 mm (P < 0.01), respectively. Preoperative planning based on simulated resection facilitated laparoscopic mobilization of the liver and mini-laparotomy resection of a large tumor located in the upper right lobe. CONCLUSIONS: Three-dimensional simulation of hepatectomy facilitated intraoperative identification of the vascular anatomy, and accurately predicted the resected liver volume and surgical margin. This simulation method should contribute to preoperative planning for safe and curative laparoscopic hepatectomy.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía/métodos , Neoplasias Hepáticas/cirugía , Hígado/diagnóstico por imagen , Cirugía Asistida por Computador/métodos , Carcinoma Hepatocelular/irrigación sanguínea , Femenino , Humanos , Hígado/cirugía , Neoplasias Hepáticas/irrigación sanguínea , Neoplasias Hepáticas/diagnóstico por imagen , Masculino , Ilustración Médica , Persona de Mediana Edad , Cuidados Preoperatorios , Tomografía Computarizada por Rayos X/métodos
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