scholarly journals A promoter region that controls basal and elicitor-inducible expression levels of the NADPH:cytochrome P450 reductase gene (Cpr ) from Catharanthus roseus binds nuclear factor GT-1

1997 ◽  
Vol 256 (6) ◽  
pp. 674-681
Author(s):  
M. I. Lopes Cardoso ◽  
A. H. Meijer ◽  
S. Rueb ◽  
J. Queiroz Machado ◽  
J. Memelink ◽  
...  
Keyword(s):  
Catharanthus Roseus ◽  
Promoter Region ◽  
Inducible Expression ◽  
Nuclear Factor ◽  
Expression Levels ◽  
P450 Reductase ◽  
Reductase Gene ◽  
Nadph:Cytochrome P450 Reductase

scholarly journals A promoter region that controls basal and elicitor-inducible expression levels of the NADPH:cytochrome P450 reductase gene (

1997 ◽  
Vol 256 (6) ◽  
pp. 674 ◽  
Author(s):  
M. I. Lopes Cardoso ◽  
A. H. Meijer ◽  
S. Rueb ◽  
J. Queiroz Machado ◽  
J. Memelink ◽  
...  
Keyword(s):  
Promoter Region ◽  
Inducible Expression ◽  
Expression Levels ◽  
P450 Reductase ◽  
Reductase Gene ◽  
Nadph:Cytochrome P450 Reductase

scholarly journals Hepatic Expression of the Mouse Angptl8 Gene Is Regulated by Insulin Through Increases in Hepatocyte Nuclear Factor-1

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A47-A48
Author(s):  
Takuya Watanabe ◽  
Takuya Watanabe ◽  
Atsushi Ozawa ◽  
Yuri Kondo ◽  
Kazuhiko Horiguchi ◽  
...  
Keyword(s):  
Promoter Region ◽  
Promoter Activity ◽  
Time Course ◽  
Binding Motif ◽  
Light Cycle ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Primary Hepatocytes ◽  
Expression Levels ◽  
Hepatic Expression

Abstract Angiopoietin-like proteins (ANGPTLs) are a family of proteins structurally similar to angiopoietins. ANGPTL8 is an important regulator of circulating triglyceride (TG) levels in mammals. Increasing evidence revealed an association between ANGPTL8 expression and serum lipid profiles, especially in subjects with metabolic syndrome. Several mice studies demonstrated that Angptl8 is suppressed by fasting and induced by long term refeeding, however the detailed mechanism is still unclear. In humans, ANGPTL8 is mainly expressed in the liver. Therefore, this study aims to investigate the mechanisms that control the refeeding induced increase in the hepatic Angptl8 gene expression. Methods and Results: Twenty-week-old male C57/BL6 mice were used in this study. Mice were fasted for 12h during the dark cycle and re-fed for 30, 60, 120, 240 and 360 minutes during the light cycle. Mice were euthanized after each refeeding time course and tissues were collected. We found even short refeeding times (~60 min) enhanced the expression levels of hepatic Angptl8 in mice. We cloned the mouse Angptl8 gene promoter region. Promoter deletion analyses showed that the basal promoter activity was significantly attenuated by a deletion of -309/-60 region in hepatocytes. A computational motif search revealed the presence of a potential binding motif for hepatocyte nuclear factor 1α/1β (HNF-1α/β) at -84/-68 bp of the promoter. Mutations of the HNF-1 binging site significantly decreased the promoter activity in mouse hepatoma cells (Hepa1-6) and mouse primary hepatocytes, and the promoter carrying the mutated HNF-1 site was not transactivated by co-transfected HNF-1 in a non-hepatic cell line. These findings indicated that HNF-1 was essential and critical factor for the basal expression of Angptl8 in murine liver. In fact, knockdown of Hnf-1 using siRNA method in mouse Hepa1-6 and mouse primary hepatocytes reduced Angptl8 protein levels. We also performed Electrophoretic mobility-shift assays and confirmed the direct binding of Hnf-1 to its Angptl8 promoter binding motif. To elucidate whether refeeding could enhance HNF-1, we checked the expression levels of Hnf-1 in mouse liver. Hnf-1 expression levels of both mRNA and protein were increased after short-term refeeding, paralleling the enhanced expression of the Angptl8. Moreover, insulin-stimulated primary hepatocytes showed increased expression of Angptl8 protein, but knockdown of Hnf-1 completely abolished this enhancement by insulin. Chromatin immunoprecipitation (ChIP) analyses confirmed the recruitment of endogenous Hnf-1 to the Angptl8 promoter region and it was strongly induced by insulin. Conclusion: HNF-1 plays essential role in hepatocyte-specific and refeeding-induced rapid increases in Angptl8 expression via insulin.

scholarly journals lncRNA MIR22HG-Derived miR-22-5p Enhances the Radiosensitivity of Hepatocellular Carcinoma by Increasing Histone Acetylation Through the Inhibition of HDAC2 Activity

2021 ◽  
Vol 11 ◽  
Author(s):  
Qiao Jin ◽  
Hao Hu ◽  
Siqi Yan ◽  
Long Jin ◽  
Yuliang Pan ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Histone Acetylation ◽  
Chromatin Immunoprecipitation ◽  
Promoter Region ◽  
Animal Experiments ◽  
Primary Hepatocellular Carcinoma ◽  
Acetylation Level ◽  
Expression Levels

BackgroundWith the development of radiotherapy technology, radiotherapy has been increasingly used to treat primary hepatocellular carcinoma (HCC). However, due to radioresistance and the intolerance of the adjacent organs to radiation, the effects of radiotherapy are often unsatisfactory. Therefore, it is necessary to study radiosensitization in HCC.MethodA microarray was used to analyze the genes that were significantly associated with radiosensitivity. HCC cells, HepG2 and MHCC97H, were subjected to radiation in vitro. Real-time PCR was performed to determine MIR22HG (microRNA22 host gene) and miR-22-5p expression levels. Western blotting was performed to determine histone expression levels. A histone deacetylase (HDAC) whole cell assay was used to determine the activity of HDAC2. MTT, colony formation, 5-ethynyl-2′-deoxyuridine, and wound healing assays were performed to examine the function of MIR22HG and miR-22-5p in cellular radiosensitivity. Chromatin immunoprecipitation-PCR was used to confirm that HDAC2 affects the acetylation level of the MIR22HG promoter region. Finally, animal experiments were performed to demonstrate the in vivo effect of MIR22HG on the radiosensitivity of hepatoma.ResultsIrradiation can up-regulate MIR22HG expression and down-regulate HDAC2 expression. Inhibition of HDAC2 expression promotes histone acetylation in the MIR22HG promoter region and up-regulates MIR22HG expression. MIR22HG can increase radiosensitivity via miR-22-5p in HCC.ConclusionInhibition of HDAC2 expression promotes histone acetylation in the MIR22HG promoter region, thereby up-regulating the expression of MIR22HG and promoting the production of miR-22-5p, and ultimately increasing the sensitivity of liver cancer radiotherapy.

Transcriptional regulation of an hsp70 heat shock gene in the yeast Saccharomyces cerevisiae

1987 ◽  
Vol 7 (5) ◽  
pp. 1906-1916
Author(s):  
M R Slater ◽  
E A Craig
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Promoter Region ◽  
Inducible Expression ◽  
Proximal Promoter ◽  
Heat Shock Gene ◽  
Heat Shock Element ◽  
Yeast Saccharomyces Cerevisiae ◽  
Hybrid Promoter ◽  
Shock Gene

The yeast Saccharomyces cerevisiae contains three heat-inducible hsp70 genes. We have characterized the promoter region of the hsp70 heat shock gene YG100, that also displays a basal level of expression. Deletion of the distal region of the promoter resulted in an 80% drop in the basal level of expression without affecting expression after heat shock. Progressive-deletion analysis suggested that sequences necessary for heat-inducible expression are more proximal, within 233 base pairs of the initiation region. The promoter region of YG100 contains multiple elements related to the Drosophila melanogaster heat shock element (HSE; CnnGAAnnT TCnnG). Deletion of a proximal promoter region containing one element, HSE2, eliminated most of the heat-inducible expression of YG100. The upstream activation site (UAS) of the yeast cytochrome c gene (CYC1) can be substituted by a single copy of HSE2 plus its adjoining nucleotides (UASHS). This hybrid promoter displayed a substantial level of expression before heat shock, and the level of expression was elevated eightfold by heat shock. YG100 sequences that flank UASHS inhibited basal expression of UASHS in the hybrid promoter but not its heat-inducible expression. This inhibition of basal UASHS activity suggests that negative regulation is involved in modulating expression of this yeast heat shock gene.

scholarly journals Mechanism of Metformin on LPS-Induced Bacterial Myocarditis

Dose-Response ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 155932581984740 ◽  
Author(s):  
Minghua Li ◽  
Yawei Gou ◽  
Hongmei Yu ◽  
Tiefeng Ji ◽  
Yi Li ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Potential Role ◽  
Nuclear Factor ◽  
Protective Effects ◽  
H9c2 Cells ◽  
Expression Levels ◽  
Opposite Trend ◽  
Mitogen Activated Protein ◽  
Related Proteins

Aims: Metformin is commonly used to treat type 2 diabetes mellitus; however, in recent years, it was found to play a potential role in the protection of myocardial injury. In this study, we intended to investigate whether metformin had protective effects on bacterial myocarditis. Methods and Results: We stimulated rat cardiac myoblast H9c2 cells with lipopolysaccharide (LPS) and administrated with metformin. The results showed that cell viability after LPS stimulation was greatly reduced. The expression levels of phosphorylated p38 mitogen-activated protein kinases (MAPK) and c-Jun N-terminal kinases (JNK), nuclear factor (NF)-κB (NF-κB), BAX, and cleaved Caspase3 were significantly increased, while the expression of antiapoptotic protein Bcl-2 showed a prominent decrease compared to control. Nevertheless, the cells activity increased remarkably after metformin administration, and the expression levels of intracellular related proteins showed the opposite trend to that of the LPS group. Conclusion: We demonstrate that LPS stimulation may activate intracellular MAPK/JNK and NF-κB signaling pathways and thus induce cell apoptosis. In contrast, metformin reduced apoptosis by inhibiting this signaling pathway and increasing the expression level of Bcl-2. Moreover, it was found that metformin could enhance the ability of cells to antagonize redox damage by regulating the activities of superoxide dismutase and lactate dehydrogenase and subsequently promote the recovery of cardiomyocyte function.

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