Glucose induces expression of rat pyruvate carboxylase through a carbohydrate response element in the distal gene promoter

2010 ◽  
Vol 426 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Kim B. Pedersen ◽  
Rebecca S. Buckley ◽  
Ray Scioneaux
Keyword(s):  
Pyruvate Carboxylase ◽  
Gene Promoter ◽  
Upstream Stimulatory Factor ◽  
Glucose Response ◽  
Response Element ◽  
Insulinoma Cell ◽  
Glucose Stimulated Insulin Secretion ◽  
Glucose Responsiveness ◽  
Distal Gene

Pyruvate carboxylase is an enzyme of the so-called pyruvate cycling pathways, which have been proposed to contribute to glucose-stimulated insulin secretion in pancreatic β-cells. In the rat insulinoma cell line 832/13, transcripts from both the distal and proximal gene promoter for pyruvate carboxylase are up-regulated by glucose, with pyruvate carboxylase being expressed mainly from the distal gene promoter. At position −408 to −392 relative to the transcription start site, the distal gene promoter was found to contain a ChoRE (carbohydrate response element). Its deletion abolishes glucose responsiveness of the promoter, and the sequence can mediate glucose responsiveness to a heterologous gene promoter. ChREBP (carbohydrate response element-binding protein) and its dimerization partner Mlx (Max-like protein X) bind to the ChoRE in vitro. ChREBP further binds to the distal promoter region at a high glucose concentration in situ. The E-box-binding transcription factors USF1/2 (upstream stimulatory factor 1/2) and E2A variant 2 [also known as E47 and TCF3 (transcription factor 3)] can also bind to the ChoRE. Overexpression of E2A diminishes the magnitude of the glucose response from the pyruvate carboxylase ChoRE. This illustrates that competition between ChREBP–Mlx and other factors binding to the ChoRE affects glucose responsiveness. We conclude that a ChoRE in the distal gene promoter contributes to the glucose-mediated expression of pyruvate carboxylase.

Glucose Responsiveness of β-Cells Depends on Fatty Acids

2019 ◽  
Vol 128 (10) ◽  
pp. 644-653
Author(s):  
Felicia Gerst ◽  
Christine Singer ◽  
Katja Noack ◽  
Dunia Graf ◽  
Gabriele Kaiser ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Insulin Secretion ◽  
Cell Function ◽  
Human Islets ◽  
In Vitro Tests ◽  
High Concentration ◽  
Β Cell Function ◽  
Glucose Stimulated Insulin Secretion ◽  
Glucose Responsiveness

AbstractGlucose-stimulated insulin secretion (GSIS) is the gold standard for β-cell function. Both experimental and clinical diabetology, i. e., preceding transplantation of isolated human islets, depend on functional testing. However, multiple factors influence GSIS rendering the comparison of different in vitro tests of glucose responsiveness difficult. This study examined the influence of bovine serum albumin (BSA)-coupled fatty acids on GSIS. Isolated islet preparations of human donors and of 12-months old mice displayed impaired GSIS in the presence of 0.5% FFA-free BSA compared to 0.5% BSA (fraction V, not deprived from fatty acids). In aged INS-1E cells, i. e. at a high passage number, GSIS became highly sensitive to FFA-free BSA. Readdition of 30 µM palmitate or 30 µM oleate to FFA-free BSA did not rescue GSIS, while the addition of 100 µM palmitate and the raise of extracellular Ca2+from 1.3 to 2.6 mM improved glucose responsiveness. A high concentration of palmitate (600 µM), which fully activates FFA1, largely restored insulin secretion. The FFA1-agonist TUG-469 also increased insulin secretion but to a lesser extent than palmitate. Glucose- and TUG-induced Ca2+oscillations were impaired in glucose-unresponsive, i. e., aged INS-1E cells. These results suggest that fatty acid deprivation (FFA-free BSA) impairs GSIS mainly through an effect on Ca2+sensitivity.

scholarly journals Upstream Stimulatory Factor (USF) Proteins Induce HumanTGF-β1Gene Activation via the Glucose-response Element–1013/–1002 in Mesangial Cells

2004 ◽  
Vol 279 (16) ◽  
pp. 15908-15915 ◽  
Author(s):  
Cora Weigert ◽  
Katrin Brodbeck ◽  
Michèle Sawadogo ◽  
Hans U. Häring ◽  
Erwin D. Schleicher
Keyword(s):  
Mesangial Cells ◽  
Upstream Stimulatory Factor ◽  
Glucose Response ◽  
Response Element ◽  
Stimulatory Factor

scholarly journals Impaired cyclic AMP-dependent phosphorylation renders CREB a repressor of C/EBP-induced transcription of the somatostatin gene in an insulinoma cell line.

1995 ◽  
Vol 15 (1) ◽  
pp. 415-424 ◽  
Author(s):  
M Vallejo ◽  
M E Gosse ◽  
W Beckman ◽  
J F Habener
Keyword(s):  
Transcription Factor ◽  
Cyclic Amp ◽  
Cell Line ◽  
Target Genes ◽  
Gene Promoter ◽  
Chloramphenicol Acetyltransferase ◽  
Negative Regulator ◽  
Insulinoma Cell ◽  
Insulinoma Cell Line

Transcription factor CREB regulates cyclic AMP (cAMP)-dependent gene expression by binding to and activating transcription from cAMP response elements (CREs) in the promoters of target genes. The transcriptional transactivation functions of CREB are activated by its phosphorylation by cAMP-dependent protein kinase A (PKA). In studies of many different phenotypically distinct cells, the CRE of the somatostatin gene promoter is a prototype of a highly cAMP-responsive element regulated by CREB. We now report on a somatostatin-producing rat insulinoma cell line, RIN-1027-B2, in which transcription from the somatostatin gene promoter is paradoxically repressed by CREB. We find that CREB fails to transactivate a CRE-containing somatostatin-chloramphenicol acetyltransferase reporter even when coexpressed with the catalytic subunit of PKA. CAAT box/enhancer-binding protein beta (C/EBP beta) and C/EBP-related activating transcription factor bind to the CRE in the promoter of the somatostatin gene and transactivate transcription. CREB binds competitively with C/EBP beta to the somatostatin CRE in vitro and represses C/EBP beta-induced transcription of the CRE-containing somatostatin-chloramphenicol acetyltransferase reporter. The lack of CREB-mediated transcriptional stimulation is due to the presence of a heat-stable inhibitor of PKA that prevents activation of PKA and subsequent CREB phosphorylation in the nucleus. These findings indicate that dephosphorylated CREB is a negative regulator of C/EBP-activated transcription of the somatostatin gene promoter in RIN-1027-B2 cells.

The promoter for the gene encoding the catalytic subunit of rat glucose-6-phosphatase contains two distinct glucose-responsive regions

2007 ◽  
Vol 292 (3) ◽  
pp. E788-E801 ◽  
Author(s):  
Kim B. Pedersen ◽  
Pili Zhang ◽  
Chris Doumen ◽  
Marcel Charbonnet ◽  
Danhong Lu ◽  
...  
Keyword(s):  
Promoter Region ◽  
Binding Protein ◽  
Catalytic Subunit ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Glucose Response ◽  
Response Element ◽  
Element Binding Protein ◽  
Insulinoma Cells ◽  
Glucose Responsiveness

Glucose homeostasis requires the proper expression and regulation of the catalytic subunit of glucose-6-phosphatase (G-6- Pase), which hydrolyzes glucose 6-phosphate to glucose in glucose-producing tissues. Glucose induces the expression of G-6- Pase at the transcriptional and posttranscriptional levels by unknown mechanisms. To better understand this metabolic regulation, we mapped the cis-regulatory elements conferring glucose responsiveness to the rat G-6- Pase gene promoter in glucose-responsive cell lines. The full-length (−4078/+64) promoter conferred a moderate glucose response to a reporter construct in HL1C rat hepatoma cells, which was dependent on coexpression of glucokinase. The same construct provided a robust glucose response in 832/13 INS-1 rat insulinoma cells, which are not glucogenic. Glucose also strongly increased endogenous G-6- Pase mRNA levels in 832/13 cells and in rat pancreatic islets, although the induced levels from islets were still markedly lower than in untreated primary hepatocytes. A distal promoter region was glucose responsive in 832/13 cells and contained a carbohydrate response element with two E-boxes separated by five base pairs. Carbohydrate response element-binding protein bound this region in a glucose-dependent manner in situ. A second, proximal promoter region was glucose responsive in both 832/13 and HL1C cells, with a hepatocyte nuclear factor 1 binding site and two cAMP response elements required for glucose responsiveness. Expression of dominant-negative versions of both cAMP response element-binding protein and CAAT/enhancer-binding protein blocked the glucose response of the proximal region in a dose-dependent manner. We conclude that multiple, distinct cis-regulatory promoter elements are involved in the glucose response of the rat G-6- Pase gene.

scholarly journals Upstream Stimulatory Factor Proteins Are Major Components of the Glucose Response Complex of the L-type Pyruvate Kinase Gene Promoter

1995 ◽  
Vol 270 (6) ◽  
pp. 2640-2643 ◽  
Author(s):  
Anne-Marie Lefran¸ois-Martinez ◽  
Antoine Martinez ◽  
Bénédicte Antoine ◽  
Michel Raymondjean ◽  
Axel Kahn
Keyword(s):  
Pyruvate Kinase ◽  
Gene Promoter ◽  
Upstream Stimulatory Factor ◽  
Kinase Gene ◽  
Glucose Response ◽  
Stimulatory Factor ◽  
Response Complex

scholarly journals Characterization of the human liver fructose-1,6-bisphosphatase gene promoter

2000 ◽  
Vol 351 (2) ◽  
pp. 385-392 ◽  
Author(s):  
Birger HERZOG ◽  
Mary WALTNER-LAW ◽  
Donald K. SCOTT ◽  
Klaus ESCHRICH ◽  
Daryl K. GRANNER
Keyword(s):  
Hormonal Regulation ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Nuclear Factor Κb ◽  
Site Directed Mutagenesis ◽  
Upstream Stimulatory Factor ◽  
Mobility Shift ◽  
Fructose 1,6 Bisphosphatase

Fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11), an important gluconeogenic enzyme, catalyses the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and Pi. Enzyme activity is mainly regulated by the allosteric inhibitors fructose 2,6-bisphosphate and AMP. Although some observations about hormonal regulation of the enzyme have been published, the FBPase promoter has not been studied in detail. Here we report an in vitro characterization of the FBPase promoter with respect to the elements that are required for basal promoter activity. Transient transfection of H4IIE rat hepatoma cells, combined with site-directed mutagenesis, demonstrated that an enhancer box, three GC-boxes and a nuclear factor κB (NF-κB)-binding element are important for hepatic FBPase promoter activity. These elements are found in the region located between -405 to +25bp relative to the transcription start site. Electrophoretic-mobility-shift assays and supershift analysis confirmed that upstream stimulatory factor 1 (USF1)/USF2, specificity protein 1 (Sp1)/Sp3 and NF-κB respectively bind to these sites. The present study provides the basis for a more comprehensive screening for mutations in FBPase-deficient patients and for further studies of the transcriptional regulation of this gene.

PREPARATION AND CHARACTERISATION OF ACETYLATED WHEAT STARCH SUPPORTING FOR DIABETES TREATMENT

2018 ◽  
Vol 8 (5) ◽  
pp. 78-84
Author(s):  
Uyen Tran Thi Ngoc ◽  
Nam Nguyen Khac ◽  
Dung Tran Huu
Keyword(s):  
Physicochemical Properties ◽  
Resistant Starch ◽  
Starch Content ◽  
Degree Of Substitution ◽  
Wheat Starch ◽  
Diabetes Treatment ◽  
Glucose Response ◽  
Swelling Capacity ◽  
Wheat Starches

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase

scholarly journals Integrin α3β1 Promotes Invasive and Metastatic Properties of Breast Cancer Cells through Induction of the Brn-2 Transcription Factor

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 480
Author(s):  
Rakshitha Pandulal Miskin ◽  
Janine S. A. Warren ◽  
Abibatou Ndoye ◽  
Lei Wu ◽  
John M. Lamar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cell Invasion ◽  
Breast Cancer Cells ◽  
Gene Promoter ◽  
Akt Inhibitor ◽  
Integrin Α3β1

In the current study, we demonstrate that integrin α3β1 promotes invasive and metastatic traits of triple-negative breast cancer (TNBC) cells through induction of the transcription factor, Brain-2 (Brn-2). We show that RNAi-mediated suppression of α3β1 in MDA-MB-231 cells caused reduced expression of Brn-2 mRNA and protein and reduced activity of the BRN2 gene promoter. In addition, RNAi-targeting of Brn-2 in MDA-MB-231 cells decreased invasion in vitro and lung colonization in vivo, and exogenous Brn-2 expression partially restored invasion to cells in which α3β1 was suppressed. α3β1 promoted phosphorylation of Akt in MDA-MB-231 cells, and treatment of these cells with a pharmacological Akt inhibitor (MK-2206) reduced both Brn-2 expression and cell invasion, indicating that α3β1-Akt signaling contributes to Brn-2 induction. Analysis of RNAseq data from patients with invasive breast carcinoma revealed that high BRN2 expression correlates with poor survival. Moreover, high BRN2 expression positively correlates with high ITGA3 expression in basal-like breast cancer, which is consistent with our experimental findings that α3β1 induces Brn-2 in TNBC cells. Together, our study demonstrates a pro-invasive/pro-metastatic role for Brn-2 in breast cancer cells and identifies a role for integrin α3β1 in regulating Brn-2 expression, thereby revealing a novel mechanism of integrin-dependent breast cancer cell invasion.

Sign in / Sign up

Export Citation Format

Share Document