scholarly journals Cytosolic sulfotransferase 2B1b promotes hepatocyte proliferation gene expression in vivo and in vitro

2012 ◽  
Vol 303 (3) ◽  
pp. G344-G355 ◽  
Author(s):  
Xin Zhang ◽  
Qianming Bai ◽  
Leyuan Xu ◽  
Genta Kakiyama ◽  
William M. Pandak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mouse Liver ◽  
Rat Hepatocytes ◽  
Hepatocyte Proliferation ◽  
Gene Expressions ◽  
Primary Rat Hepatocytes ◽  
Liver Proliferation ◽  
Liver Tissues

Cytosolic sulfotransferase 2B1b (SULT2B1b) catalyzes the sulfation of 3β-hydroxysteroids and functions as a selective cholesterol and oxysterol sulfotransferase. Activation of liver X receptors (LXRs) by oxysterols has been known to be an antiproliferative factor. Overexpression of SULT2B1b impairs LXR's response to oxysterols, by which it regulates lipid metabolism. The aim of this study was to investigate in vivo and in vitro effects of SULT2B1b on liver proliferation and the underlying mechanisms. Primary rat hepatocytes and C57BL/6 mice were infected with adenovirus encoding SULT2B1b. Liver proliferation was determined by measuring the proliferating cell nuclear antigen (PCNA) immunostaining labeling index. The correlation between SULT2B1b and PCNA expression in mouse liver tissues was determined by double immunofluorescence. Gene expressions were evaluated by quantitative real-time PCR and Western blot analysis. SULT2B1b overexpression in mouse liver tissues increased PCNA-positive cells in a dose- and time-dependent manner. The increased expression of PCNA in mouse liver tissues was only observed in the SULT2B1b transgenic cells. Small interference RNA SULT2B1b significantly inhibited cell cycle regulatory gene expressions in primary rat hepatocytes. LXR activation by T0901317 effectively suppressed SULT2B1b-induced gene expression in vivo and in vitro. SULT2B1b may promote hepatocyte proliferation by inactivating oxysterol/LXR signaling.

scholarly journals Regulation of Spi 2.1 and 2.2 gene expression after turpentine inflammation: discordant responses to IL-6

1999 ◽  
Vol 276 (6) ◽  
pp. C1374-C1382 ◽  
Author(s):  
Susan A. Berry ◽  
Pearl L. Bergad ◽  
Allison M. Stolz ◽  
Howard C. Towle ◽  
Sarah Jane Schwarzenberg
Keyword(s):  
Gene Expression ◽  
Acute Phase ◽  
Gene Promoter ◽  
Rat Hepatocytes ◽  
Acute Phase Reactants ◽  
Primary Rat Hepatocytes ◽  
Fold Induction ◽  
Vitro Model

The rat serine protease inhibitor (Spi) 2 gene family includes both positive (Spi 2.2) and negative (Spi 2.1) acute phase reactants, facilitating modeling of regulation of hepatic acute phase response (APR). To examine the role of signal transducer and activation of transcription (STAT) proteins in the divergent regulation of these model genes after induction of APR, we evaluated the proximal promoters of the genes, focusing on STAT binding sites contained in these promoter elements. Induction of APR by turpentine injection includes activation of a STAT3 complex that can bind to a γ-activated sequence (GAS) in the Spi 2.2 gene promoter, although the Spi 2.2 GAS site can bind STAT1 or STAT5 as well. To create an in vitro model of APR, primary hepatocytes were treated with combinations of cytokines and hormones to mimic the hormonal milieu of the whole animal after APR induction. Incubation of primary rat hepatocytes with interleukin (IL)-6, a critical APR cytokine, leads to activation of STAT3 and a 28-fold induction of a chloramphenicol acetyltransferase reporter construct containing the −319 to +85 region of the Spi 2.2 promoter. This suggests the turpentine-induced increase of Spi 2.2 is mediated primarily by IL-6. In contrast, although turpentine treatment reduces Spi 2.1 mRNA in vivo and IL-6 does not increase Spi 2.1 mRNA in primary rat hepatocytes, treatment of hepatocytes with IL-6 results in a 5.4-fold induction of Spi 2.1 promoter activity mediated through the paired GAS elements in this promoter. Differential regulation of Spi 2.1 and 2.2 genes is due in part to differences in the promoters of these genes at the GAS sites. IL-6 alone fails to reproduce the pattern of rat Spi 2 gene expression that results from turpentine-induced inflammation.

Abstract 41: Explant-Derived Cells from Chronic Heart Failure Activated Endothelial-Mesenchymal Transition and Attenuated Pluripotency Genes Expression

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Liudmila Zakharova ◽  
Hikmet Nural ◽  
Mohamed A Gaballa
Keyword(s):  
Gene Expression ◽  
Progenitor Cells ◽  
Smooth Muscle Actin ◽  
Fold Increase ◽  
Gene Expressions ◽  
Mesenchymal Transition ◽  
Cell Outgrowth ◽  
Pluripotency Genes

Cardiac progenitor cells are generated from atria explants; however the cellular origin and the mechanisms of cell outgrowth are unclear. Using transgenic tamoxifen-induced Willms tumor 1 (Wt1)-Cre/ERT and Cre-activated GFP reporter mice, we found approximately 40% of explant-derived cells and 74% of explant-derived c-Kit+ cells originated from the epicardium. In atria from sham hearts, Wt1+ cells were located in a thin epicardial layer, while c-Kit+ cells were primarily found within both the sub-epicardium and the myocardium, albeit at low frequency. No overlap between c-Kit+ and Wt1+ cells was observed, suggesting that epicardial Wt1+ cells do not express c-Kit marker in vivo, but more likely the c-Kit marker was acquired in culture. Compared with 4 days in culture, at day 21 we observed 7 folds increase in Snail gene expression; 32% increase in α-smooth muscle actin (SMA) marker, and 30% decrease in E-cadherin marker, suggesting that the explant-derived cells underwent epithelial to mesenchymal transition (EMT) in vitro. Cell outgrowths released TGF-β (1036.4 ± 1.18 pm/ml) and exhibited active TGF-β signaling, which might triggered the EMT. Compared to shams, CHF cell outgrowths exhibited elevated levels of EMT markers, SMA (49% vs. 34%) and Snail (2 folds), and reduced level of Wt1 (11% vs. 22%). In addition, CHF cell outgrowths had two folds increase in Pai1 gene expression, a direct target of TGF-β signaling. In c-Kit+ cells derived from CHF explants, Nanog gene expression was 4 folds lower and Sox 2 was 2 folds lower compared with cells from shams. Suppression of EMT in cell outgrowth increased the percentage of c-Kit+ and Wt1+ cells by 17%, and 15%, respectively. Also suppression of EMT in c-Kit+ cells resulted in 4 folds increase in Nanog and 3 fold increase in Sox2 gene expressions. Our results showed that CHF may further exuberates EMT while diminishes the re-activation of pluripotency genes. Thus, EMT modulation in CHF is a possible strategy to regulate both the yield and the pluripotency of cardiac-explant-derived progenitor cells.

Comparison of hepatocarcinogen-induced gene expression profiles in conventional primary rat hepatocytes with in vivo rat liver

2012 ◽  
Vol 86 (9) ◽  
pp. 1399-1411 ◽  
Author(s):  
Tatyana Y. Doktorova ◽  
Heidrun Ellinger-Ziegelbauer ◽  
Mathieu Vinken ◽  
Tamara Vanhaecke ◽  
Joost van Delft ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Rat Hepatocytes ◽  
Primary Rat Hepatocytes

Bidirectional Oscillatory Shear Stress Increases Pro-Atherogenic Gene Expressions (I-CAM1, E-Selectin and IL-6) in Endothelial Cells

2011 ◽  
Author(s):  
Amlan Chakraborty ◽  
Venkatakrishna R. Jala ◽  
Sutirtha Chakraborty ◽  
R. Eric Berson ◽  
M. Keith Sharp ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Atherosclerotic Plaque ◽  
Inflammatory Diseases ◽  
Leukotriene B4 ◽  
Oscillatory Shear ◽  
Gene Expressions

Wall shear stress (WSS) plays a key role in altering intracellular pathways and gene expression of endothelial cells, and has significant impacts on atherosclerotic plaque development (1–3). Further, the atherogenic regulators Leukotriene B4 (LTB4) and Lipopolysaccharide (LPS) have significant impacts on the pathophysiology of many inflammatory diseases. This study investigates the effects of oscillatory shear directionality on pro-atherogenic gene expression (I-CAM, E-Selectin, and IL-6) in the presence of LTB4 and LPS. An orbital shaker was used to expose the endothelial cells to oscillatory shear in culture dishes, and Computational fluid dynamics (CFD) was applied to quantify the shear stress on the bottom of the orbiting dish. Directionality of oscillatory shear was characterized by a newly developed hemodynamic parameter — Directional oscillatory shear index (DOSI), which was demonstrated in a previous study to significantly impact cell morphology (4). Results showed that DOSI significantly altered gene expression. Therefore, directionality of shear modulates atherosclerotic gene expression in vitro and thus, may influence the formation of atherosclerotic plaque in vivo.

Solved in vivo/in vitro discrepancy in methapyrilene induced gene alterations in rat liver and in collagen sandwich cultured primary rat hepatocytes

2009 ◽  
Vol 189 ◽  
pp. S77
Author(s):  
Markus Schug ◽  
Tanja Heise ◽  
Georgia Günther ◽  
Dorothe Storm ◽  
Axel Oberemm ◽  
...  
Keyword(s):  
Rat Liver ◽  
Rat Hepatocytes ◽  
Primary Rat Hepatocytes ◽  
Gene Alterations

Cobalt exerts opposite effects on erythropoietin gene expression in rat hepatocytes in vivo and in vitro

1995 ◽  
Vol 269 (5) ◽  
pp. R995-R1001
Author(s):  
T. Gopfert ◽  
K. U. Eckardt ◽  
B. Gess ◽  
A. Kurtz
Keyword(s):  
Gene Expression ◽  
Oxygen Sensor ◽  
Rat Hepatocytes ◽  
Inhibitory Effect ◽  
Ribonuclease Protection Assay ◽  
Mrna Levels ◽  
Adult Rats ◽  
Ribonuclease Protection

This study investigates the effects of hypoxia and of cobalt on erythropoietin (EPO) gene expression in hepatocytes in vivo and in vitro in neonatal, juvenile, and adult rats. With the use of the ribonuclease protection assay to quantify RNA, both hypoxia (0.1% CO or 9% O2) and cobalt (60 mg/kg) elicit production of increased amounts of EPO mRNA in neonatal and juvenile rat liver in vivo. In vitro hepatocyte EPO gene expression could be reproducibly stimulated by hypoxia (3% O2) but not by cobaltous chloride (50-150 microM) within 2-20 h. Conversely, cobalt substantially attenuated the rise of EPO mRNA levels in response to hypoxia. This inhibitory effect of cobalt was mimicked by zinc but not by other metals. CO attenuated the rise of EPO mRNA levels in vitro in response to hypoxia; this inhibitory effect coincided with an inhibition of total RNA synthesis as determined by [3H]uridine incorporation. The lack of specific inhibitory effects of CO and of specific stimulatory effects of cobalt on hepatocyte EPO gene expression in vitro suggests that a specific heme oxygen sensor may be less important than in hepatoma cells.

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