scholarly journals Carcinogen-induced trans activation of gene expression.

1988 ◽  
Vol 8 (3) ◽  
pp. 1366-1370 ◽  
Author(s):  
T Kleinberger ◽  
Y B Flint ◽  
M Blank ◽  
S Etkin ◽  
S Lavi

We report a new mechanism of carcinogen action by which the expression of several genes was concomitantly enhanced. This mechanism involved the altered activity of cellular factors which modulate the expression of genes under their control. The increased expression was regulated at least in part on the transcriptional level and did not require amplification of the overexpressed genes. This phenomenon was transient; it was apparent as early as 24 h after carcinogen treatment and declined a few days later.

1988 ◽  
Vol 8 (3) ◽  
pp. 1366-1370
Author(s):  
T Kleinberger ◽  
Y B Flint ◽  
M Blank ◽  
S Etkin ◽  
S Lavi

We report a new mechanism of carcinogen action by which the expression of several genes was concomitantly enhanced. This mechanism involved the altered activity of cellular factors which modulate the expression of genes under their control. The increased expression was regulated at least in part on the transcriptional level and did not require amplification of the overexpressed genes. This phenomenon was transient; it was apparent as early as 24 h after carcinogen treatment and declined a few days later.


2017 ◽  
Vol 102 (8) ◽  
pp. 3040-3049 ◽  
Author(s):  
Natalia Matulewicz ◽  
Magdalena Stefanowicz ◽  
Agnieszka Nikołajuk ◽  
Monika Karczewska-Kupczewska

Abstract Context In obesity, adipose tissue (AT) undergoes dynamic remodeling, including an alternation in adipogenesis, AT-resident cell content, angiogenesis, and turnover of extracellular matrix (ECM) components. Studies of AT in humans have been carried out mostly in people with severe metabolic abnormalities, like type 2 diabetes or morbid obesity. Objective The purpose of this study was to investigate subcutaneous AT gene expression of markers of adipogenesis, ECM remodeling, and inflammation in young, healthy, overweight or obese subjects. Design The study group comprised 83 normal-weight, 48 overweight, and 19 obese subjects. Euglycemic hyperinsulinemic clamp, biopsy of subcutaneous AT, and isolation of peripheral blood mononuclear cells (PBMCs) were performed. Gene expression was measured with real-time polymerase chain reaction. Results Overweight/obese subjects had lower AT expression of markers of adipogenesis, insulin signaling, and angiogenesis; higher expression of markers of ECM remodeling; altered expression of genes of the nuclear factor-κ-B (NFκB), but not c-Jun NH2-terminal kinase, pathway; and higher expression of macrophage markers but not markers of other immune cells. In multiple regression analysis, the expression of CEBPA, ADIPOQ, IRS1, IRS2, SLC2A4, and MMP9 was associated with insulin sensitivity independently of body mass index. No differences were found in inflammatory-gene PBMC expression. Conclusion Overweight/obesity is associated with altered expression of genes of adipogenesis, insulin signaling, ECM remodeling, and inflammation. NFκB seems to be the earliest inflammatory pathway altered at the transcriptional level in AT. Macrophages seem to be the first immune cells to infiltrate AT. Adipogenesis and ECM remodeling are the initial processes in AT that are independently associated with insulin sensitivity.


2009 ◽  
Vol 103 (5) ◽  
pp. 696-702 ◽  
Author(s):  
Astrid de Greeff ◽  
Machteld Huber ◽  
Lucy van de Vijver ◽  
Willem Swinkels ◽  
Henk Parmentier ◽  
...  

Using a nutrigenomics approach we studied the response of second-generation chickens at a transcriptional level to organically grown feed ingredients compared with conventionally grown feed ingredients. Both diets consisted of the same amounts of ingredients, the only difference was the production method. Gene expression was analysed in jejuni using whole genome chicken cDNA arrays. After analysis, forty-nine genes were found to be differentially regulated between chickens fed on the different diets, independent of their genetic background. Of these forty-nine genes, seven genes were involved in cholesterol biosynthesis. Genes involved in cholesterol biosynthesis were higher expressed in jejuni from organically fed birds. Other genes found to be regulated were involved in immunological processes, such as B-G protein (part of chicken major histocompatibility complex), chemokine ah221, and the immunoglobulin heavy chain. Using quantitative PCR the effect of genetic background on the differential expression of genes was studied. Differences in gene expression existed between animals fed different diets as well as between different chicken lines. This indicated that diet and genetic background influence the transcriptional response of the jejunum. This is the first time that significant differences in gene expression were shown between animals on diets with organically or conventionally produced ingredients.


2021 ◽  
Author(s):  
Sarah Belhocine ◽  
Andre Machado Xavier ◽  
Félix Distéfano-Gagné ◽  
Stéphanie Fiola ◽  
Serge Rivest ◽  
...  

SummaryMicroglia proliferation occurs during brain development and brain lesions, but how this is coordinated at the transcriptional level is not well understood. Here, we investigated transcriptional mechanisms underlying proliferation of mouse microglia during postnatal development and in adults in models of induced microglial depletion-repopulation and brain demyelination. While each proliferative subset displayed globally a distinct signature of gene expression, they also co-expressed a subgroup of 1,370 genes at higher levels than quiescent microglia. Furthermore, expression of these may be coordinated by one of two modes of regulation. A first mode augments expression of genes already expressed in quiescent microglia and is subject to regulation by Klf/Sp, Nfy, and Ets transcription factors. Alternatively, a second mode enables de novo transcription of cell cycle genes and requires additional regulatory input from Lin54 and E2f factors. Overall, proliferating microglia integrate regulation of cell cycle gene expression with their broader, context-dependent, transcriptional landscape.


Author(s):  
Tara A Shrout

Cardiac hypertrophy is a growth process that occurs in response to stress stimuli or injury, and leads to the induction of several pathways to alter gene expression. Under hypertrophic stimuli, sarcomeric structure is disrupted, both as a consequence of gene expression and local changes in sarcomeric proteins. Cardiac-restricted ankyrin repeat protein (CARP) is one such protein that function both in cardiac sarcomeres and at the transcriptional level. We postulate that due to this dual nature, CARP plays a key role in maintaining the cardiac sarcomere. GATA4 is another protein detected in cardiomyocytes as important in hypertrophy, as it is activated by hypertrophic stimuli, and directly binds to DNA to alter gene expression. Results of GATA4 activation over time were inconclusive; however, the role of CARP in mediating hypertrophic growth in cardiomyocytes was clearly demonstrated. In this study, Neonatal Rat Ventricular Myocytes were used as a model to detect changes over time in CARP and GATA4 under hypertrophic stimulation by phenylephrine and high serum media. Results were detected by analysis of immunoblotting. The specific role that CARP plays in mediating cellular growth under hypertrophic stimuli was studied through immunofluorescence, which demonstrated that cardiomyocyte growth with hypertrophic stimulation was significantly blunted when NRVMs were co-treated with CARP siRNA. These data suggest that CARP plays an important role in the hypertrophic response in cardiomyocytes.


2011 ◽  
Vol 33 (12) ◽  
pp. 1300-1307
Author(s):  
Xiu-Jun ZHANG ◽  
Mei-Ling LIU ◽  
Meng-Chun JIA

2020 ◽  
Vol 20 (12) ◽  
pp. 1487-1496 ◽  
Author(s):  
Midori Murakami ◽  
Hiroto Izumi ◽  
Tomoko Kurita ◽  
Chiho Koi ◽  
Yasuo Morimoto ◽  
...  

Background: Cisplatin is an important anticancer agent in cancer chemotherapy, but when resistant cells appear, treatment becomes difficult, and the prognosis is poor. Objective: In this study, we investigated the gene expression profile in cisplatin sensitive and resistant cells, and identified the genes involved in cisplatin resistance. Methods: Comparison of gene expression profiles revealed that UBE2L6 mRNA is highly expressed in resistant cells. To elucidate whether UBE2L6 is involved in the acquisition of cisplatin resistance, UBE2L6- overexpressing cells established from cisplatin-sensitive cells and UBE2L6-silenced cells developed from cisplatin- resistant cells were generated, and the sensitivity of cisplatin was examined. Results: The sensitivity of the UBE2L6-overexpressing cells did not change compared with the control cells, but the UBE2L6-silenced cells were sensitized to cisplatin. To elucidate the mechanism of UBE2L6 in cisplatin resistance, we compared the gene expression profiles of UBE2L6-silenced cells and control cells and found that the level of ABCB6 mRNA involved in cisplatin resistance was decreased. Moreover, ABCB6 promoter activity was partially suppressed in UBE2L6-silenced cells. Conclusion: These results suggest that cisplatin-resistant cells have upregulated UBE2L6 expression and contribute to cisplatin resistance by regulating ABCB6 expression at the transcriptional level. UBE2L6 might be a molecular target that overcomes cisplatin resistance.


Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1427
Author(s):  
Tiago Barros Afonso ◽  
Lúcia Chaves Simões ◽  
Nelson Lima

Biofilms can be considered the main source of microorganisms in drinking water distribution systems (DWDS). The ecology of a biofilm is dependent on a variety of factors, including the presence of microbial metabolites excreted by its inhabitants. This study reports the effect of the Gram-negative bacteria Methylobacterium oryzae on the idh gene expression levels and patulin production of Penicillium expansum mature biofilms. For this purpose, a RT-qPCR method to quantify idh mRNA levels was applied. In addition, the idh expression levels were compared with the patulin production. The results obtained revealed that the effect of the bacterium on pre-established P. expansum biofilms is dependent on the time of interaction. More mature P. expansum biofilms appear to be more resistant to the inhibitory effect that M. oryzae causes towards idh gene expression and patulin production. A positive trend was observed between the idh expression and patulin production values. The results indicate that M. oryzae affects patulin production by acting at the transcriptional level of the idh gene.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Fan ◽  
Jiayu Peng ◽  
Jiacheng Wu ◽  
Ping Zhou ◽  
Ruijie He ◽  
...  

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.


2021 ◽  
Vol 11 (11) ◽  
pp. 4723
Author(s):  
Rosaria Scudiero ◽  
Chiara Maria Motta ◽  
Palma Simoniello

The cleidoic eggs of oviparous reptiles are protected from the external environment by membranes and a parchment shell permeable to water and dissolved molecules. As a consequence, not only physical but also chemical insults can reach the developing embryos, interfering with gene expression. This review provides information on the impact of the exposure to cadmium contamination or thermal stress on gene expression during the development of Italian wall lizards of the genus Podarcis. The results obtained by transcriptomic analysis, although not exhaustive, allowed to identify some stress-reactive genes and, consequently, the molecular pathways in which these genes are involved. Cadmium-responsive genes encode proteins involved in cellular protection, metabolism and proliferation, membrane trafficking, protein interactions, neuronal transmission and plasticity, immune response, and transcription regulatory factors. Cold stress changes the expression of genes involved in transcriptional/translational regulation and chromatin remodeling and inhibits the transcription of a histone methyltransferase with the probable consequence of modifying the epigenetic control of DNA. These findings provide transcriptome-level evidence of how terrestrial vertebrate embryos cope with stress, giving a key to use in population survival and environmental change studies. A better understanding of the genes contributing to stress tolerance in vertebrates would facilitate methodologies and applications aimed at improving resistance to unfavourable environments.


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