scholarly journals Microarray Transcription Profiling of a Shewanella oneidensis etrA Mutant

2002 ◽  
Vol 184 (16) ◽  
pp. 4612-4616 ◽  
Author(s):  
Alex S. Beliaev ◽  
Dorothea K. Thompson ◽  
Matthew W. Fields ◽  
Liyou Wu ◽  
Douglas P. Lies ◽  
...  

ABSTRACT DNA microarrays were used to examine the effect of an insertional mutation in the Shewanella oneidensis etrA (electron transport regulator) locus on gene expression under anaerobic conditions. The mRNA levels of 69 genes with documented functions in energy and carbon metabolism, regulation, transport, and other cellular processes displayed significant alterations in transcript abundance in an etrA-mutant genetic background. This is the first microarray study indicating a possible involvement of EtrA in the regulation of gene expression in S. oneidensis MR-1.

2003 ◽  
Vol 185 (18) ◽  
pp. 5611-5626 ◽  
Author(s):  
Eric Soupene ◽  
Wally C. van Heeswijk ◽  
Jacqueline Plumbridge ◽  
Valley Stewart ◽  
Daniel Bertenthal ◽  
...  

ABSTRACT Escherichia coli strain MG1655 was chosen for sequencing because the few mutations it carries (ilvG rfb-50 rph-1) were considered innocuous. However, it has a number of growth defects. Internal pyrimidine starvation due to polarity of the rph-1 allele on pyrE was problematic in continuous culture. Moreover, the isolate of MG1655 obtained from the E. coli Genetic Stock Center also carries a large deletion around the fnr (fumarate-nitrate respiration) regulatory gene. Although studies on DNA microarrays revealed apparent cross-regulation of gene expression between galactose and lactose metabolism in the Stock Center isolate of MG1655, this was due to the occurrence of mutations that increased lacY expression and suppressed slow growth on galactose. The explanation for apparent cross-regulation between galactose and N-acetylglucosamine metabolism was similar. By contrast, cross-regulation between lactose and maltose metabolism appeared to be due to generation of internal maltosaccharides in lactose-grown cells and may be physiologically significant. Lactose is of restricted distribution: it is normally found together with maltosaccharides, which are starch degradation products, in the mammalian intestine. Strains designated MG1655 and obtained from other sources differed from the Stock Center isolate and each other in several respects. We confirmed that use of other E. coli strains with MG1655-based DNA microarrays works well, and hence these arrays can be used to study any strain of interest. The responses to nitrogen limitation of two urinary tract isolates and an intestinal commensal strain isolated recently from humans were remarkably similar to those of MG1655.


1997 ◽  
Vol 273 (2) ◽  
pp. R762-R767 ◽  
Author(s):  
A. Chaudhry ◽  
J. G. Granneman

Brown adipose tissue (BAT) expresses several adenylyl cyclase (AC) subtypes, and adrenergic stimulation selectively upregulates AC-III gene expression. Previous studies have described synergistic interactions between the sympathetic nervous system (SNS) and 3,5,3'-triiodothyronine (T3) on the regulation of gene expression in BAT. Because adrenergic stimulation also increases the activity of BAT type II thyroxine 5'-deiodinase (DII) and local T3 generation is important for many functional responses in BAT, we examined the effects of thyroid hormone status on the expression of various AC subtypes. Hypothyroidism selectively increased AC-III mRNA levels in BAT but not in white adipose tissue. Of the other subtypes examined, hypothyroidism did not alter AC-VI mRNA levels and slightly reduced AC-IX mRNA levels in BAT. The increase in AC-III expression was paralleled by an increase in forskolin-stimulated AC activity in BAT membranes. Sympathetic denervation of BAT abolished the increase in both AC activity and AC-III mRNA expression produced by hypothyroidism, but did not affect the expression of other subtypes. Surgical denervation also prevented the induction of AC-III in the cold-stressed euthyroid rat, but injections of T3 failed to alter AC-III expression in intact or denervated BAT. Our results indicate that T3 does not directly affect expression of AC-III. Rather, hypothyroidism increases BAT AC-III expression indirectly via an increase in sympathetic stimulation. Furthermore, our results strongly indicate that the increase in AC activity in hypothyroid BAT is due to increased expression of AC-III.


Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3932-3940 ◽  
Author(s):  
Hongyan Dong ◽  
Carole L. Yauk ◽  
Andrew Williams ◽  
Alice Lee ◽  
George R. Douglas ◽  
...  

The molecular mechanisms involved in the response of developing mice to disruptions in maternal thyroid hormone (TH) homeostasis are poorly characterized. We used DNA microarrays to examine a broad spectrum of genes from the livers of mice rendered hypothyroid by treating pregnant mice from gestational d 13 to postnatal d 15 with 6-propyl-2-thiouracil in drinking water. Twenty-four individuals (one male and one female pup from six litters of control or 6-propyl-2-thiouracil treatment groups, respectively) were profiled using Agilent oligonucleotide microarrays. MAANOVA identified 96 differentially expressed genes (false discovery rate adjusted P < 0.1 and fold change > 2 in at least one gender). Of these, 72 genes encode proteins of known function, 15 of which had previously been identified as regulated by TH. Pathway analysis revealed these genes are involved in metabolism, development, cell proliferation, apoptosis, and signal transduction. An immediate-early response gene, Nr4a1 (nuclear receptor subfamily 4, group A, member 1), was up-regulated by 3-fold in hypothyroid juvenile mouse liver; treatment of HepG2 cells with T3 resulted in down-regulation of Nr4a1. A potential thyroid response element −1218 to −1188 bp upstream of the promoter region of Nr4a1 was identified and demonstrated to bind TH receptor (TR)-α and TRβ. Point mutation or deletion of the sequence containing the potential Nr4a1-thyroid response element in transient gene expression studies resulted in both higher basal expression and loss of T3 regulatory capacity, suggesting that this site is responsible for the negative regulation of gene expression by TR and TH.


2008 ◽  
Vol 33 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Carl Virtanen ◽  
Mark Takahashi

Adaptations that are the result of exercise require a multitude of changes at the level of gene expression. The mechanisms involved in regulating these changes are many, and can occur at various points in the pathways that affect gene expression. The completion of the human genome sequence, along with the genomes of related species, has provided an enormous amount of information to help dissect and understand these pathways. High-throughput methods, such as DNA microarrays, were the first on the scene to take advantage of this wealth of information. A new generation of microarrays has now taken the next step in revealing the mechanisms controlling gene expression. Analysis of the regulation of gene expression can now be profiled in a high-throughput fashion. However, the application of this technology has yet to be fully realized in the exercise physiology community. This review will highlight some of the latest advances in microarrays and briefly discuss some potential applications to the field of exercise physiology.


2015 ◽  
Vol 103 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Mina Kazemzadeh ◽  
Reza Safaralizadeh ◽  
Mohammad Ali HosseinPour feizi ◽  
Mohammad Hossein Somi ◽  
Behrooz Shokoohi

Background Long non-coding RNAs (lncRNAs), a class of regulatory RNAs, play a major role in various cellular processes. Long intergenic non-coding RNAs (lincRNAs), a subclass of lncRNAs, are involved in the trans- and cis-regulation of gene expression. In the case of cis-regulation, by recruiting chromatin-modifying complexes, lincRNAs influence adjacent gene expression. Methods We used quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) to evaluate the coexpression of LOC100287225, a lincRNA, and DCC, one of its adjacent genes that is often decreased in colorectal cancer, in pairs of tumor and adjacent tumor-free tissues of 30 colorectal cancer patients. Results The qRT-PCR results revealed the misregulation of these genes during tumorigenesis. Their relative expression levels were significantly lower in tumor tissues than adjacent tumor-free tissues. However, the analysis found no significant correlation between reduced expression of these genes. Conclusions Our study demonstrated the concurrent misregulation of DCC and LOC100287225 in colorectal cancer.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Guangbing Li ◽  
Haohai Zhang ◽  
Xueshuai Wan ◽  
Xiaobo Yang ◽  
Chengpei Zhu ◽  
...  

Long noncoding RNAs (lncRNAs) have been attracting immense research interests. However, only a handful of lncRNAs had been thoroughly characterized. They were involved in fundamental cellular processes including regulation of gene expression at epigenetics as well as tumorogenesis. In this paper, we give a systematic and comprehensive review of existing literature about lncRNA involvement in hepatocellular carcinoma. This review exhibited that lncRNAs played important roles in tumorigenesis and subsequent prognosis and metastasis of hepatocellular carcinoma and elucidated the role of some specific lncRNAs such as MALAT1 and HOTAIR in the pathophysiology of hepatocellular carcinoma and their potential of being therapeutic targets.


2007 ◽  
Vol 92 (7) ◽  
pp. 2688-2695 ◽  
Author(s):  
Giuseppe Murdolo ◽  
Ann Hammarstedt ◽  
Madeléne Sandqvist ◽  
Martin Schmelz ◽  
Christian Herder ◽  
...  

Abstract Context: The chemokine monocyte chemoattractant protein-1 (MCP-1) is implicated in obesity-associated chronic inflammation, insulin resistance, and atherosclerosis. Objectives: The objectives of this study were to: 1) characterize the interstitial levels and the gene expression of MCP-1 in the sc abdominal adipose tissue (SCAAT), 2) elucidate the response of MCP-1 to acute hyperinsulinemia, and 3) determine the relationship between MCP-1 and arterial stiffness. Design: Nine lean (L) and nine uncomplicated obese (OB) males were studied in the fasting state and during a euglycemic-hyperinsulinemic clamp combined with the microdialysis technique. Interstitial and serum MCP-1 (iMCP-1 and sMCP-1, respectively) levels, pulse wave analysis, and SCAAT biopsies were characterized at baseline and after hyperinsulinemia. Results: OB showed elevated sMCP-1 (P < 0.01) but similar iMCP-1 levels as compared with L. Basal iMCP-1 concentrations were considerably higher than sMCP-1 (P < 0.0001), and a gradient between iMCP-1 and sMCP-1 levels was maintained throughout the hyperinsulinemia. At baseline, SCAAT gene expression profile revealed a “co-upregulation” of MCP-1, MCP-2, macrophage inflammatory protein-1α, and CD68 in OB, and whole-body glucose disposal inversely correlated with the MCP-1 gene expression. After hyperinsulinemia, MCP-1 and MCP-2 mRNA levels significantly increased in L, but not in OB. Finally, sMCP-1 excess in the OB positively correlated with the stiffer vasculature. Conclusions: These observations demonstrate similar interstitial concentrations and a differential gene response to hyperinsulinemia of MCP-1 in the SCAAT from L and OB individuals. In human obesity, we suggest the SCAAT MCP-1 gene overexpression as a biomarker of an “inflamed” adipose organ and impaired glucose metabolism.


2000 ◽  
Vol 167 (1) ◽  
pp. R1-R5 ◽  
Author(s):  
M Imae ◽  
Y Inoue ◽  
Z Fu ◽  
H Kato ◽  
T Noguchi

Hepatocyte nuclear factor-3 (HNF-3) belongs to a large family of forkhead transcription factors and is made up of three members (HNF-3alpha, -3beta and -3gamma). It has been shown that HNF-3 regulates a number of metabolically important genes. However, the mechanisms underlying this regulation of HNF-3 activity by hormones and nutrition have not yet been well elucidated. In attempting to explore the regulation of gene expression of HNF-3 members by physiological status, we analyzed the effects of insulin, dexamethasone and protein malnutrition on the hepatic mRNA level of each member. Male Wistar rats were fed on a 12% casein diet, 12% gluten diet (deficient in lysine and threonine) or a protein-free diet for 1 week. The protein-free diet and gluten diet caused a 3. 7-fold increase in HNF-3g mRNA in the liver and did not affect the mRNA level of either HNF-3alpha or HNF-3beta. Daily administration of dexamethasone caused the mRNA levels of HNF-3alpha and HNF-3beta to increase (2.3- and 1.4-fold, respectively), but had no effect on the HNF-3gamma mRNA level. In diabetic rats that had been injected with streptozotocin, an elevation of the hepatic mRNA levels of HNF-3beta and HNF-3gamma was observed (1.6-and 1.9-fold, respectively). Insulin replacement in the diabetic rats decreased both mRNA levels in a dose-dependent manner. HNF-3alpha mRNA was not affected by insulin status. These results show that the genes of the three members of the HNF-3 family respond differently to hormonal and nutritional factors suggesting that the activities of HNF-3 members are regulated, at least in part, by the levels of their gene expression.


2012 ◽  
Vol 78 (16) ◽  
pp. 5699-5707 ◽  
Author(s):  
James Matsunaga ◽  
Mariana L. Coutinho

ABSTRACTLeptospirosis is a potentially deadly zoonotic disease that afflicts humans and animals.Leptospira interrogans, the predominant agent of leptospirosis, encounters diverse conditions as it proceeds through its life cycle, which includes stages inside and outside the host. Unfortunately, the number of genetic tools available for examining the regulation of gene expression inL. interrogansis limited. Consequently, little is known about the genetic circuits that control gene expression inLeptospira. To better understand the regulation of leptospiral gene expression, theL. interrogans kdplocus, encoding homologs of the P-type ATPase KdpABC potassium transporter with their KdpD sensors and KdpE response regulators, was selected for analysis. We showed that akdpEmutation inL. interrogansprevented the increase inkdpABCmRNA levels observed in the wild-typeL. interrogansstrain when external potassium levels were low. To confirm that KdpE was a positive regulator ofkdpABCtranscription, we developed a novel approach for constructing chromosomal genetic fusions to the endogenousbgaL(β-galactosidase) gene of the nonpathogenLeptospira biflexa. We demonstrated positive regulation of akdpA′-bgaLfusion inL. biflexaby theL. interrogansKdpE response regulator. A controllipL32′-bgaLfusion was not regulated by KdpE. These results demonstrate the utility of genetic fusions to thebgaLgene ofL. biflexafor examining leptospiral gene regulation.


2017 ◽  
Author(s):  
Christian Oertlin ◽  
Julie Lorent ◽  
Valentina Gandin ◽  
Carl Murie ◽  
Laia Masvidal ◽  
...  

ABSTRACTmRNA translation plays an evolutionarily conserved role in homeostasis and when dysregulated results in various disorders. Optimal and universally applicable analytical methods to study transcriptome-wide changes in translational efficiency are therefore critical for understanding the complex role of translation regulation under physiological and pathological conditions. Techniques used to interrogate translatomes, including polysome- and ribosome-profiling, require adjustment for changes in total mRNA levels to capture bona fide alterations in translational efficiency. Herein, we present the anota2seq algorithm for such analysis using data from ribosome- or polysome-profiling quantified by DNA-microarrays or RNA sequencing, which outperforms current methods for identification of changes in translational efficiency. In contrast to available analytical methods, anota2seq also allows capture of an underappreciated mode for regulation of gene expression whereby translation acts as a buffering mechanism which maintains constant protein levels despite fluctuations in mRNA levels (“translational buffering”). Application of anota2seq shows that insulin affects gene expression at multiple levels, in a largely mTOR-dependent manner. Moreover, insulin induces levels of a subset of mRNAs independently of mTOR that undergo translational buffering upon mTOR inhibition. Thus, the universal anota2seq algorithm allows efficient and hitherto unprecedented interrogation of translatomes and enables studies of translational buffering which represents an unexplored mechanism for regulating of gene expression.


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