scholarly journals Regulation of GLUT5 gene expression in rat intestinal mucosa: regional distribution, circadian rhythm, perinatal development and effect of diabetes

1995 ◽  
Vol 309 (1) ◽  
pp. 271-277 ◽  
Author(s):  
A Castelló ◽  
A Gumá ◽  
L Sevilla ◽  
M Furriols ◽  
X Testar ◽  
...  

1. GLUT5 gene expression was studied in small intestine under a variety of conditions characterized by altered intestinal absorption of monosaccharides. 2. RNA-blotting studies showed that GLUT5 mRNA was abundantly expressed in rat and rabbit intestine and kidney, but it was not detected in heart or brown adipose tissue. GLUT5 mRNA levels were higher in the upper segments of the small intestine (duodenum and proximal jejunum) than in the lower segments (distal jejunum and ileum). 3. The intestinal expression of GLUT5 mRNA in rat proximal jejunum showed circadian rhythm. A 12-fold increase in GLUT5 mRNA levels was detected at the end of the light cycle and at the beginning of the dark cycle when compared with the early light period. In keeping with this, GLUT5 protein content in brush-border membranes was also increased at the beginning of the dark cycle compared with that in the light period. 4. In streptozotocin-induced diabetes an 80% increase in GLUT5 mRNA levels in mucosa from the proximal jejunum was detected under conditions in which enhanced intestinal absorption of monosaccharides has been reported. 5. The intestinal expression of GLUT5 mRNA showed regulation during perinatal development. Levels of GLUT5 mRNA were low during fetal life, increased progressively during the postnatal period and reached levels comparable with the adult state after weaning. Weaning on to a high-fat diet partially prevented the induction of GLUT5 gene expression. 6. Our results indicate that GLUT5 gene expression is tightly regulated in small intestine. Regulation involves maximal expression in the upper part of the small intestine, circadian rhythm, developmental regulation dependent on the fat and carbohydrate content in the diet at weaning and enhanced expression in streptozotocin-induced diabetes. Furthermore, changes observed in intestinal GLUT5 expression correlate with reported alterations in intestinal absorption of fructose. This suggests a regulatory role for GLUT5 in fructose uptake by absorptive enterocytes.

Cephalalgia ◽  
2017 ◽  
Vol 38 (3) ◽  
pp. 496-502 ◽  
Author(s):  
Carmen Fourier ◽  
Caroline Ran ◽  
Margret Zinnegger ◽  
Anne-Sofie Johansson ◽  
Christina Sjöstrand ◽  
...  

Background Cluster headache is characterized by recurrent unilateral headache attacks of severe intensity. One of the main features in a majority of patients is a striking rhythmicity of attacks. The CLOCK ( Circadian Locomotor Output Cycles Kaput) gene encodes a transcription factor that serves as a basic driving force for circadian rhythm in humans and is therefore particularly interesting as a candidate gene for cluster headache. Methods We performed an association study on a large Swedish cluster headache case-control sample (449 patients and 677 controls) screening for three single nucleotide polymorphisms (SNPs) in the CLOCK gene implicated in diurnal preference (rs1801260) or sleep duration (rs11932595 and rs12649507), respectively. We further wanted to investigate the effect of identified associated SNPs on CLOCK gene expression. Results We found a significant association with rs12649507 and cluster headache ( p = 0.0069) and this data was strengthened when stratifying for reported diurnal rhythmicity of attacks ( p = 0.0009). We investigated the effect of rs12649507 on CLOCK gene expression in human primary fibroblast cultures and identified a significant increase in CLOCK mRNA expression ( p = 0.0232). Conclusions Our results strengthen the hypothesis of the involvement of circadian rhythm in cluster headache.


2008 ◽  
Vol 32 (2) ◽  
pp. 170-181 ◽  
Author(s):  
Jun Yan ◽  
Brian M. Barnes ◽  
Franziska Kohl ◽  
Thomas G. Marr

We performed a broadscale screening of differential gene expression using both high-throughput bead-array technology and real-time PCR assay in brown adipose tissue, liver, heart, hypothalamus, and skeletal muscle in hibernating arctic ground squirrels, comparing animals sampled after two durations of steady-state torpor, during two stages of spontaneous arousal episodes, and in animals after they ended hibernation. Significant seasonal and torpor-arousal cycle differences of gene expression were detected in genes involved in glycolysis, fatty acid metabolism, gluconeogenesis, amino acid metabolism, molecular transport, detoxification, cardiac contractility, circadian rhythm, cell growth and apoptosis, muscle dystrophy, and RNA and protein protection. We observed, for the first time, complex modulation of gene expression during multiple stages of torpor-arousal cycles. The mRNA levels of certain metabolic genes drop significantly during the transition from late torpor to early arousal, perhaps due to the rapid turnover of mRNA transcripts resulting from the translational demands during thermogenesis in early arousal, whereas the mRNA levels of genes related to circadian rhythm, cell growth, and apoptosis rise significantly in the early or late arousal phases during torpor-arousal cycle, suggesting the resumption of circadian rhythm and cell cycle during arousal.


1997 ◽  
Vol 324 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Sean H. ADAMS ◽  
Clarice S. ALHO ◽  
Guillermina ASINS ◽  
Fausto G. HEGARDT ◽  
Pedro F. MARRERO

The low ketogenic capacity of pigs correlates with a low activity of mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase. To identify the molecular mechanism controlling such activity, we isolated the pig cDNA encoding this enzyme and analysed changes in mRNA levels and mitochondrial specific activity induced during development and starvation. Pig mitochondrial synthase showed a tissue-specific expression pattern. As with rat and human, the gene is expressed in liver and large intestine; however, the pig differs in that mRNA was not detected in testis, kidney or small intestine. During development, pig mitochondrial HMG-CoA synthase gene expression showed interesting differences from that in the rat: (1) there was a 2–3 week lag in the postnatal induction; (2) the mRNA levels remained relatively abundant through the suckling–weaning transition and at maturity, in contrast with the fall observed in rats at similar stages of development; and (3) the gene expression was highly induced by fasting during the suckling, whereas no such change in mitochondrial HMG-CoA synthase mRNA levels has been observed in rat. The enzyme activity of mitochondrial HMG-CoA synthase increased 27-fold during starvation in piglets, but remained one order of magnitude lower than rats. These results indicate that post-transcriptional mechanism(s) and/or intrinsic differences in the encoded enzyme are responsible for the low activity of pig HMG-CoA synthase observed throughout development or after fasting.


1993 ◽  
Vol 265 (4) ◽  
pp. R781-R785 ◽  
Author(s):  
E. L. Robinson ◽  
V. H. Demaria-Pesce ◽  
C. A. Fuller

Phase or amplitude differences between rhythms in heat production (HP) and heat loss (HL) have been suggested to account for the circadian rhythm in body temperature (Tb). To describe the relationships among these rhythms in a primate, five unrestrained squirrel monkeys (1.0-1.3 kg) were studied using combined direct and indirect calorimetry, with telemetry of Tb and activity, in a 24-h light-dark cycle (LD 12:12) at 25 +/- 0.5 degrees C. Dry (D; sensible) HL, evaporative (E) HL, HP (oxygen consumption and CO2 production), Tb, and activity were measured at 10-min intervals for a week. Tb, activity, HP, and HL displayed daily rhythms, peaking during the light period. Although the timing of peaks was not significantly different, the diurnal increase in Tb was seen to result from a delayed increase in DHL, and possibly, EHL, relative to increased HP. The nocturnal decrease in Tb was due to different time courses of decrease in HP and HL, with no clear lag in HL. The rhythm in Tb therefore resulted from both phase and time course differences in HP and HL rhythms.


2003 ◽  
Vol 285 (4) ◽  
pp. G714-G725 ◽  
Author(s):  
Shannon L. Jenkins ◽  
Jiafang Wang ◽  
Mukta Vazir ◽  
Jose Vela ◽  
Omar Sahagun ◽  
...  

Numerous genes expressed by intestinal epithelial cells are developmentally regulated, and the influence that adaptive (AI) and passive (PI) immunity have in controlling their expression has not been evaluated. In this study, we tested the hypothesis that both PI and AI influenced enterocyte gene expression by developing a breeding scheme that used T and B cell-deficient recombination-activating gene ( RAG) mice. RNA was isolated from the liver and proximal/distal small intestine at various ages, and the steady-state levels of six different transcripts were evaluated by RNase protection assay. In wild-type (WT) pups, all transcripts [Fc receptor of the neonate ( FcRn), polymeric IgA receptor ( pIgR), GLUT5, lactase-phlorizin hydrolase ( lactase), apical sodium-dependent bile acid transporter ( ASBT), and Na+/glucose cotransporter ( SGLT1)] studied were developmentally regulated at the time of weaning, and all transcripts except ASBT had the highest levels of expression in the proximal small intestine. In WT suckling pups reared in the absence of PI, pIgR mRNA levels were increased 100% during the early phase of development. In mice lacking AI, the expression of pIgR and lactase were significantly attenuated, whereas FcRn and GLUT5 levels were higher compared with WT mice. Finally, in the absence of both passive and active immunity, expression levels of pIgR and lactase were significantly lower than similarly aged WT mice. In summary, we report that the adaptive and passive immune status of mice influences steady-state mRNA levels of several important, developmentally regulated enterocyte genes during the suckling and weaning periods of life.


2016 ◽  
Vol 7 (3) ◽  
pp. 421-429 ◽  
Author(s):  
A. Aoki-Yoshida ◽  
S. Saito ◽  
S. Fukiya ◽  
R. Aoki ◽  
Y. Takayama ◽  
...  

Administration of Lactobacillus rhamnosus GG (LGG) has been reported to be therapeutically effective against acute secretory diarrhoea resulting from the structural and functional intestinal mucosal lesions induced by rotavirus infection; however, the underlying mechanisms remain to be completely elucidated. Because Toll-like receptor 3 (TLR3) plays a key role in the innate immune responses following the recognition of rotavirus, the present study examined whether LGG influences TLR3 gene expression in murine small intestine ex vivo and in vivo. We employed cultured intestinal organoids derived from small intestinal crypts as an ex vivo tissue model. LGG supplementation increased TLR3 mRNA levels in the intestinal organoids, as estimated by quantitative real-time polymerase chain reaction. Likewise, single and 7-day consecutive daily administrations of LGG increased TLR3 mRNA levels in the small intestine of C57BL/6N mice. The mRNA levels of other TLRs were not substantially altered both ex vivo and in vivo. In addition, LGG supplementation increased the mRNA levels of an antiviral type 1 interferon, interferon-α (IFN-α), and a neutrophil chemokine, CXCL1, upon stimulation with a synthetic TLR3 ligand, poly(I:C) in the intestinal organoids. LGG administration did not alter IFN-α and CXCL1 mRNA levels in the small intestine in vivo. Supplementation of other bacterial strains, Bifidobacterium bifidum and Lactobacillus paracasei, failed to increase TLR3 and poly(I:C)-stimulated CXCL1 mRNA levels ex vivo. We propose that upregulation of TLR3 gene expression may play a pivotal role in the therapeutic efficacy of LGG against rotavirus-associated diarrhoea. In addition, we demonstrated that intestinal organoids may be a promising ex vivo tissue model for investigating host-pathogen interactions and the antiviral action of probiotics in the intestinal epithelium.


1992 ◽  
Vol 262 (1) ◽  
pp. G123-G130 ◽  
Author(s):  
P. G. Traber ◽  
L. Yu ◽  
G. D. Wu ◽  
T. A. Judge

The mucosal lining of the small intestine is a complex epithelium that is continually renewed by division of a stem cell population located in intestinal crypts, migration of daughter cells along the villus, and, finally, extrusion of senescent cells into the lumen. The majority of cells in both crypt and villus cell compartments are enterocytes that acquire differentiated functions as they migrate out of the crypt. Sucrase-isomaltase (SI) is an enterocyte-specific, brush-border enzyme that has little activity in crypt cells and maximal activity in low and mid villus cells. The mechanism by which enterocytes acquire SI enzymatic activity as they move from crypt to villus is controversial. In this study we examined the distribution of SI mRNA along the crypt-villus axis of human small intestine using isolated epithelial cells and in situ hybridization. A complementary DNA to the 5' portion of the human SI mRNA was amplified and cloned using the polymerase chain reaction. Hybridization analysis of RNA extracted from human intestinal epithelial cells showed that the cloned cDNA recognized a single 6.5-kb mRNA. In situ hybridization of duodenal biopsy specimens was performed using a single-stranded RNA probe derived from this cDNA. This analysis showed that there was little SI mRNA in crypt cells and appearance of mRNA in enterocytes located at the crypt-villus junction. The mRNA levels were maximal in lower and mid villus cells with decreased levels noted in villus tip cells. These results are identical to those previously described in rat intestine and suggest that expression of the SI gene as enterocytes emerge from intestinal crypts is regulated primarily at the level of mRNA accumulation. Study of SI gene regulation may provide a useful model to investigate the mechanisms that regulate enterocyte-specific gene expression and intestinal differentiation.


Thorax ◽  
2001 ◽  
Vol 56 (7) ◽  
pp. 541-548
Author(s):  
E M Glare ◽  
M Divjak ◽  
M J Bailey ◽  
E H Walters

BACKGROUNDAsthma has been described as an eosinophilic bronchitis driven by interleukin(IL)-4 and IL-5. The quantification of cytokine mRNA levels in airway samples has been confounded by housekeeping gene expression which differs between and within asthmatics and controls.METHODSThe usefulness of competitive reverse transcriptase-polymerase chain reaction (RT-PCR) that is independent of housekeeping gene expression for quantitating the mRNA for interferon (IFN)γ, IL-2, IL-5, IL-4 and its receptor antagonist encoding splicing variant IL-4δ2 was determined in a cross sectional study of 45 normal control subjects and 111 with asthma.RESULTSAtopic controls and atopic asthmatic subjects expressed more IL-5 than non-atopic controls (p<0.02) in bronchoalveolar lavage (BAL) cells, but not in biopsy specimens. IL-5 mRNA expression in BAL cells from asthmatic subjects using inhaled corticosteroids (ICS) was significantly lower than those not receiving ICS (p=0.04). IL-2 mRNA levels differed with steroid use in biopsy specimens but not in BAL cells. IFNγ, IL-4, and IL-4δ2 mRNA levels did not differ between any groups and were not affected by steroid use. IL-4 and IL-4δ2 mRNA levels were positively correlated (p<0.0001), suggesting coordinated transcription.CONCLUSIONSWhile the signal differentiation of competitive PCR in asthma may rival that of in situ hybridisation and immunohistochemistry, the method is expensive and wasteful of material.


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.


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