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Koeberlein B.,University Hospital of Tuebingen | Hausen A.z.,Albert Ludwigs University of Freiburg | Bektas N.,RWTH Aachen | Zentgraf H.,German Cancer Research Center | And 7 more authors.
Virus Research | Year: 2010

The mechanism by which hepatitis B virus (HBV) infection causes severe inflammatory liver diseases is multifactorial and related to interactions with cell signaling pathways and the ensuing inflammatory response. Activation of JAK/STAT/SOCS signaling is essential for the induction of cellular antiviral responses, contributes to apoptosis and is negatively regulated by SOCS proteins. Recent reports have shown that SOCS3 activation interferes with viral protein expression and treatment response and thereby plays a major role in hepatitis virus infections. We analyzed the expression of SOCS3 in liver specimens from HBV-infected patients using immunohistochemistry (IHC) and determined the effect of HBV on STAT/SOCS signaling in functional cell culture experiments (HuH-7) using HBV-expressing adenoviral constructs (AdHBV). Increased expression of SOCS3 protein was identified in liver specimens from patients with chronic HBV-infection and this correlated with the severity of liver inflammation. In accordance with the IHC-findings, in vitro analyses demonstrated that HBV infection of HuH7 cells was associated with increased expression of SOCS3 protein. In spite of the over expression of its negative regulator SOCS3 we observed a constitutive activation of STAT3. SOCS1 levels were not increased while pSTAT1 was suppressed in HBV-infected HuH7 cells. Our results demonstrate that STAT/SOCS-signaling is dysregulated in HBV-infected hepatocytes both in vivo and in vitro and this correlated with the severity of liver inflammatory changes. This interference of STAT/SOCS signaling by HBV may result in an ineffective immune response against HBV and potentially contributes to viral pathogenesis, malignant transformation and may represent an important mechanism of viral persistence. © 2009 Elsevier B.V. Source


Dang P.H.,Vietnam National University, Ho Chi Minh City | Nguyen N.T.,Vietnam National University, Ho Chi Minh City | Nguyen H.X.,Vietnam National University, Ho Chi Minh City | Nguyen L.B.,Vietnam National University, Ho Chi Minh City | And 4 more authors.
Fitoterapia | Year: 2015

A novel and rare 1,4-dehydrated ceramide, embelamide (1), and a new C-glycoalkaloid which is based on a β-carboline ring system, 1-(2′-deoxy-α-d-ribopyranosyl)-β-carboline (4), were isolated from the CHCl3 soluble fraction of the leaves of Embelia ribes (Myrsinaceae), together with thirteen known compounds (2-3, 5-15). Their structures were elucidated on the basis of spectroscopic data. Compounds 1, and 5-12 possessed significant α-glucosidase inhibitory activity in a concentration-dependent manner, and showed more potent inhibitory activity, with IC50 values ranging from 1.3 to 155.0 μM, than that of a positive control acarbose (IC50, 214.5 μM). © 2014 Elsevier B.V. All rights reserved. Source


Ito M.,University of Toyama | Nakashima A.,University of Toyama | Hidaka T.,University of Toyama | Okabe M.,University of Toyama | And 8 more authors.
Journal of Reproductive Immunology | Year: 2010

Chorioamnionitis (CAM) is a major cause of preterm delivery. Inflammatory cytokines and chemokines play important roles in the pathogenesis of preterm delivery. Interleukin (IL)-17 is a key cytokine which induces inflammation and is critical to host defense. In this study, we examined the role of IL-17 in the pathogenesis of preterm delivery. The levels of cytokines including IL-17, IL-8 and tumor necrosis factor (TNF) α were measured by ELISA in amniotic fluid from 154 cases of preterm labor. Flow cytometry and immunohistochemical staining were performed to determine the distribution of IL-17-producing cells. IL-8 secretion was evaluated in primary cultured human amniotic mesenchymal (HAM) cells and human amniotic epithelial (HAE) cells stimulated with IL-17, TNFα or IL-1β. We also studied the signaling pathway of IL-17 and TNFα in HAM cells. Levels of inflammatory cytokines in amniotic fluid were higher in preterm delivery cases than in term delivery cases. Furthermore, IL-8, IL-17 and TNFα levels were significantly higher in the preterm cases with CAM stage II or III than those without CAM. Flow cytometry and immunohistochemical staining revealed that CD3+CD4+ T cells were the main source of IL-17 in the chorioamniotic membrane. Interestingly, TNFα-induced IL-8 secretion was enhanced by IL-17 in a dose-dependent manner in HAM cells. The IKK inhibitor BMS-345541 and mitogen-activated protein kinase (MAPK) inhibitors p38, JNK and p42/44 (ERK1/2 pathway) reduced IL-8 secretion by IL-17-stimulated and TNFα-stimulated HAM cells. These results indicate that IL-17, produced by T cells, promotes inflammation at the fetomaternal interface in preterm delivery. © 2009 Elsevier Ireland Ltd. All rights reserved. Source


Anh N.T.N.,Kanazawa Medical University | Nishijo M.,Kanazawa Medical University | Tai P.T.,Vietnam Military Medical University | Maruzeni S.,Kanazawa Medical University | And 7 more authors.
Journal of Exposure Science and Environmental Epidemiology | Year: 2014

This study looked to identify determinants of exposure to dioxin in breast milk from breast-feeding women in a hot spot of dioxin exposure in Vietnam. Breast milk was collected from 140 mothers 1 month after delivery. The risk factors investigated included length of residency, drinking of well water and the frequency of animal food consumption. Cluster analysis was performed to identify dietary patterns of fish and meat portions, fish variety and egg variety. Residency, age and parity were clearly associated with increased dioxin levels. Drinking well water and the consumption of marine crab and shrimps were related to higher levels of furans in breast milk. The consumption of quail eggs also appeared to be associated with increased levels of some dioxin isomers in this area. Some mothers who ate no or less meat than fish and mothers who consumed more freshwater fish than marine fish had lower levels of dioxins in their breast milk. However, the type of water and the eating habits of mothers contributed only partly to the increased dioxin levels in their breast milk; the length of residency was the most important risk factor associated with increased dioxin body burdens of mothers. © 2014 Nature America, Inc. All rights reserved. Source


Tai P.T.,Kanazawa Medical University | Tai P.T.,Vietnam Military Medical University | Nishijo M.,Kanazawa Medical University | Anh N.T.N.,Kanazawa Medical University | And 7 more authors.
Occupational and Environmental Medicine | Year: 2013

Objectives Dioxin levels in the breast milk of mothers residing near hot spots of dioxin contamination areas in South Vietnam remain much higher than in unsprayed areas, suggesting that fetuses and breast-fed infants may be exposed to high levels of dioxins. The present study investigated the association of infant neurodevelopment in early infancy and dioxin exposure during the perinatal period. Methods The study involved 216 mother-infant pairs living near the Da Nang airbase, a dioxin contaminated area in Vietnam. Mothers and infants were followed from birth until infants were 4 months old. Dioxin levels in breast milk were measured to estimate the perinatal dioxin exposure, including the infant daily dioxin intake (DDI) via breastfeeding. Infant neurodevelopmental parameters, including cognitive, language and motor domains were assessed at approximately 4 months using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III). Results The level of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated dibenzo-p-dioxins/ furans-toxic equivalents in breast milk and the infant DDI showed significant inverse correlations with neurodevelopmental scores. When the subjects were divided into four groups according to dioxin levels in breast milk, the moderate and high DDI groups had significantly lower cognitive, composite motor and fine motor scores, and the high polychlorinated dibenzo-p-dioxins/furans-toxic equivalents group had significantly lower fine motor score than the low exposure group. For all domains, neurodevelopmental scores were decreased with increase in the level of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Conclusion The present study demonstrates a considerable impact of perinatal dioxin exposure on neurodevelopment in 4-month-old infants living in contaminated areas in Vietnam. Source

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