Diet-induced epigenetic regulation in vivo of the intestinal fructose transporter Glut5 during development of rat small intestine

2011 ◽  
Vol 435 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Takuji Suzuki ◽  
Veronique Douard ◽  
Kazuki Mochizuki ◽  
Toshinao Goda ◽  
Ronaldo P. Ferraris

Metabolic complications arising from excessive fructose consumption are increasing dramatically even in young children, but little is known about ontogenetic mechanisms regulating Glut5 [glucose transporter 5; encoded by the Slc2a5 (solute carrier family 2 member 5) gene]. Glut5 expression is low postnatally and does not increase, unless luminal fructose and systemic glucocorticoids are present, until ≥14 days of age, suggesting substrate-inducible age- and hormone-sensitive regulation. In the present study, we perfused intestines of 10- and 20-day-old rats with either fructose or glucose then analysed the binding of Pol II (RNA polymerase II) and GR (glucocorticoid receptor), as well as acetylation of histones H3 and H4 by chromatin immunoprecipitation. Abundance of Glut5 mRNA increased only with fructose perfusion and age, a pattern that matched that of Pol II binding and histone H3 acetylation to the Glut5 promoter. Although many regions of the Glut5 promoter respond to developmental signals, fewer regions perceive dietary signals. Age- but not fructose-dependent expression of Sglt1 [sodium-dependent glucose co-transporter 1 encoded by the Slc5a1(solute carrier family 5 member 1) gene] also correlated with Pol II binding and histone H3 acetylation. In contrast, G6Pase (glucose-6-phosphatase; encoded by the G6pc gene) expression, which decreases with age and increases with fructose, is associated only with age-dependent changes in histone H4 acetylation. Induction of Glut5 during ontogenetic development appears to be specifically mediated by GR translocation to the nucleus and subsequent binding to the Glut5 promoter, whereas the glucocorticoid-independent regulation of Sglt1 by age was not associated with any GR binding to the Sglt1 promoter.

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Emily Hsu ◽  
Nathan R Zemke ◽  
Arnold J Berk

Regulation of RNA Polymerase II (Pol2) elongation in the promoter proximal region is an important and ubiquitous control point for gene expression in metazoans. We report that transcription of the adenovirus 5 E4 region is regulated during the release of paused Pol2 into productive elongation by recruitment of the super elongation complex (SEC), dependent on promoter H3K18/27 acetylation by CBP/p300. We also establish that this is a general transcriptional regulatory mechanism that applies to ~6% of expressed protein-coding genes in primary human airway epithelial cells. We observed that a homeostatic mechanism maintains promoter, but not enhancer H3K18/27ac in response to extensive inhibition of CBP/p300 acetyl transferase activity by the highly specific small molecule inhibitor A-485. Further, our results suggest a function for BRD4 association at enhancers in regulating paused Pol2 release at nearby promoters. Taken together, our results uncover processes regulating transcriptional elongation by promoter region histone H3 acetylation and homeostatic maintenance of promoter, but not enhancer, H3K18/27ac in response to inhibition of CBP/p300 acetyl transferase activity.


2020 ◽  
Author(s):  
E Hsu ◽  
NR Zemke ◽  
AJ Berk

SummaryRegulation of RNA Polymerase II (Pol2) elongation in the promoter proximal region is an important and ubiquitous control point for gene expression in metazoan cells. We report that transcription of the adenovirus 5 E4 region is regulated during the release of paused Pol2 into productive elongation by recruitment of the super elongation complex (SEC), dependent on promoter H3K18/27 acetylation by CBP/p300. We also establish that this is a general transcriptional regulatory mechanism for ∼6% of genes expressed with FPKM>1 in primary human airway epithelial cells. We observed that a homeostatic mechanism maintains promoter, but not enhancer H3K18/27ac in response to extensive inhibition of CBP/p300 acetyl transferase activity by the highly specific small molecule inhibitor A-485. Further, our results suggest a function for BRD4 association at enhancers in regulating paused Pol2 release at nearby promoters. Taken together, our results uncover processes regulating transcriptional elongation by promoter region histone H3 acetylation and homeostatic maintenance of promoter, but not enhancer, H3K18/27ac in response to inhibition of CBP/p300 acetyl transferase activity.


Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 525 ◽  
Author(s):  
Liqian Zhu ◽  
Xinyi Jiang ◽  
Xiaotian Fu ◽  
Yanhua Qi ◽  
Guoqiang Zhu

During bovine herpesvirus 1 (BoHV-1) productive infection in cell cultures, partial of intranuclear viral DNA is present in nucleosomes, and viral protein VP22 associates with histones and decreases histone H4 acetylation, indicating the involvement of histone H4 acetylation in virus replication. In this study, we demonstrated that BoHV-1 infection at the late stage (at 24 h after infection) dramatically decreased histone H3 acetylation [at residues K9 (H3K9ac) and K18 (H3K18ac)], which was supported by the pronounced depletion of histone acetyltransferases (HATs) including CBP/P300 (CREB binding protein and p300), GCN5L2 (general control of amino acid synthesis yeast homolog like 2) and PCAF (P300/CBP-associated factor). The depletion of GCN5L2 promoted by virus infection was partially mediated by ubiquitin-proteasome pathway. Interestingly, the viral replication was enhanced by HAT (histone acetyltransferase) activator CTPB [N-(4-Chloro-3-trifluoromethylphenyl)-2-ethoxy-6-pentadecylbenzamide], and vice versa, inhibited by HAT inhibitor Anacardic acid (AA), suggesting that BoHV-1 may take advantage of histone acetylation for efficient replication. Taken together, we proposed that the HAT-dependent histone H3 acetylation plays an important role in BoHV-1 replication in MDBK (Madin-Darby bovine kidney) cells.


2007 ◽  
Vol 27 (22) ◽  
pp. 7886-7894 ◽  
Author(s):  
A. Francesca Setiadi ◽  
Muriel D. David ◽  
Robyn P. Seipp ◽  
Jennifer A. Hartikainen ◽  
Rayshad Gopaul ◽  
...  

ABSTRACT Downregulation of the transporter associated with antigen processing 1 (TAP-1) has been observed in many tumors and is closely associated with tumor immunoevasion mechanisms, growth, and metastatic ability. The molecular mechanisms underlying the relatively low level of transcription of the tap-1 gene in cancer cells are largely unexplained. In this study, we tested the hypothesis that epigenetic regulation plays a fundamental role in controlling tumor antigen processing and immune escape mechanisms. We found that the lack of TAP-1 transcription in TAP-deficient cells correlated with low levels of recruitment of the histone acetyltransferase, CBP, to the TAP-1 promoter. This results in lower levels of histone H3 acetylation at the TAP-1 promoter, leading to a decrease in accessibility of the RNA polymerase II complex to the TAP-1 promoter. These observations suggest that CBP-mediated histone H3 acetylation normally relaxes the chromatin structure around the TAP-1 promoter region, allowing transcription. In addition, we found a hitherto-unknown mechanism wherein interferon gamma up-regulates TAP-1 expression by increasing histone H3 acetylation at the TAP-1 promoter locus. These findings lie at the heart of understanding immune escape mechanisms in tumors and suggest that the reversal of epigenetic codes may provide novel immunotherapeutic paradigms for intervention in cancer.


2015 ◽  
Vol 308 (9) ◽  
pp. L962-L972 ◽  
Author(s):  
Rachel L. Clifford ◽  
Jamie K. Patel ◽  
Alison E. John ◽  
Amanda L. Tatler ◽  
Lisa Mazengarb ◽  
...  

Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation.


2018 ◽  
Vol 19 (12) ◽  
pp. 4071 ◽  
Author(s):  
Mei-Chi Chang ◽  
Yunn-Jy Chen ◽  
Yun-Chia Lian ◽  
Bei-En Chang ◽  
Chih-Chia Huang ◽  
...  

Butyric acid as a histone deacetylase (HDAC) inhibitor is produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium, etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells, etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on the matrix and mineralization marker expression in MG-63 osteoblasts. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/annexin V flow cytometry. The protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, matrix metalloproteinase-2 (MMP-2), osteonectin (SPARC), osteocalcin and osteopontin (OPN) secretion into culture medium were measured by enzyme-linked immunosorbant assay. Alkaline phosphatase (ALP) activity was checked by ALP staining. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and Western blot. We found that butyrate activated the histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell viability with no marked increase in apoptosis and necrosis. Twenty-four hours of exposure to butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas the sRANKL level was below the detection limit. However, 3 days of exposure to butyrate (1 to 8 mM) or other HDAC inhibitors such as phenylbutyrate, valproic acid and trichostatin stimulated OPG secretion. Butyrate stimulated 8-isoprostane, MMP-2 and OPN secretion, but not procollagen I, or osteocalcin in MG-63 cells. Exposure to butyrate (2–4 mM) for 3 days markedly stimulated osteonectin secretion and ALP activity. In conclusion, higher concentrations of butyric acid generated by periodontal and root canal microorganisms may potentially induce bone destruction and impair bone repair by the alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2 and OPN secretion, and affect cell viability. However, lower concentrations of butyrate (1–4 mM) may stimulate ALP, osteonectin and OPG. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis and repair of periodontal and periapical destruction.


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