scholarly journals Gene expression of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in a poorly ketogenic mammal: effect of starvation during the neonatal period of the piglet

1997 ◽  
Vol 324 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Sean H. ADAMS ◽  
Clarice S. ALHO ◽  
Guillermina ASINS ◽  
Fausto G. HEGARDT ◽  
Pedro F. MARRERO
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Small Intestine ◽  
Neonatal Period ◽  
Specific Activity ◽  
Mrna Levels ◽  
Specific Expression ◽  
Order Of Magnitude ◽  
Specific Expression Pattern ◽  
Low Activity

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.

Hepatocellular expression of glucose-6-phosphatase is unaltered during hepatic regeneration

1998 ◽  
Vol 275 (4) ◽  
pp. G717-G722 ◽  
Author(s):  
Wisam F. Zakko ◽  
Carl L. Berg ◽  
John L. Gollan ◽  
Richard M. Green
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Protein Expression ◽  
Partial Hepatectomy ◽  
Initial Phase ◽  
Physiological Function ◽  
Liver Homogenate ◽  
Hepatic Regeneration ◽  
Mrna Levels ◽  
Microsomal Enzyme

Gluconeogenesis and glycogenolysis are essential hepatic functions required for glucose homeostasis. During the initial phase of hepatic regeneration, the immediate-early genes (IEG) are rapidly expressed, and the IEG RL-1 encodes for glucose-6-phosphatase (G-6- Pase). G-6- Pase is a microsomal enzyme essential for gluconeogenesis and glycogenolysis. This study employs a partial-hepatectomy model to examine the expression and activity of G-6- Pase. After partial hepatectomy, rat hepatic G-6- Pase gene expression is transcriptionally regulated, and mRNA levels are increased ≈30-fold. However, in contrast to this rapid gene induction, microsomal enzyme activity is unchanged after partial hepatectomy. Western blotting demonstrates that microsomal G-6- Pase protein expression is also unchanged after partial hepatectomy, and similar results are also noted in whole liver homogenate. Thus, despite marked induction in gene expression of the IEG G-6- Pase after partial hepatectomy, protein expression and enzyme activity remain unchanged. These data indicate that, although this hepatocyte IEG is transcriptionally regulated, the physiologically important level of regulation is posttranscriptional. This highlights the importance of correlating gene expression of IEG with protein expression and physiological function.

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 ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Circadian Rhythm ◽  
Intestinal Absorption ◽  
Light Period ◽  
Proximal Jejunum ◽  
Mrna Levels ◽  
Dark Cycle ◽  
Perinatal Development ◽  
Streptozotocin Induced Diabetes

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.

scholarly journals Glucocorticoid hormones downregulate histidine decarboxylase mRNA and enzyme activity in rat lung

1998 ◽  
Vol 275 (2) ◽  
pp. L407-L413 ◽  
Author(s):  
Cynthia A. Zahnow ◽  
Pertti Panula ◽  
Atsushi Yamatodani ◽  
David E. Millhorn
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Adrenal Gland ◽  
Histidine Decarboxylase ◽  
Mrna Levels ◽  
Glucocorticoid Hormones ◽  
Rat Lung ◽  
Dexamethasone Treatment ◽  
Inflammatory Disorders ◽  
Corticosterone Treatment

Histidine decarboxylase (HDC) is the primary enzyme regulating histamine biosynthesis. Histamine contributes to the pathogenesis of chronic inflammatory disorders such as asthma. Because glucocorticoids are effective in the treatment of asthma, we examined the effects of 6 h of exogenously administered dexamethasone (0.5–3,000 μg/kg ip), corticosterone (0.2–200 mg/kg ip), or endogenously elevated corticosterone (via exposure of rats to 10% oxygen) on HDC expression in the rat lung. HDC transcripts were decreased ∼73% with dexamethasone treatment, 57% with corticosterone treatment, and 50% with exposure to 10% oxygen. Likewise, HDC enzyme activity was decreased 80% by treatment with dexamethasone and corticosterone and 60% by exposure to 10% oxygen. Adrenalectomy prevented the decreases in HDC mRNA and enzyme activity observed in rats exposed to 10% oxygen, suggesting that the adrenal gland is necessary for the mediation of hypoxic effects on HDC gene expression. These results demonstrate that corticosteroids initiate a process that leads to the decrease of HDC mRNA levels and enzyme activity in rat lung.

Lineage-specific defect in gene expression in human platelet phospholipase C-β2 deficiency

Blood ◽  
2002 ◽  
Vol 99 (3) ◽  
pp. 905-911 ◽  
Author(s):  
Guang Fen Mao ◽  
Vijender R. Vaidyula ◽  
Satya P. Kunapuli ◽  
A. Koneti Rao
Keyword(s):  
Gene Expression ◽  
Phospholipase C ◽  
Internal Control ◽  
Healthy Subjects ◽  
Leukotriene B4 ◽  
Calcium Mobilization ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Specific Expression ◽  
Platelet Factor

Abstract Phospholipase C (PLC)–β2 plays a major role in platelet activation. Previous studies have described a unique patient with impaired receptor-mediated platelet aggregation, secretion, calcium mobilization, and phospholipase C (PLC) activation associated with a selective decrease in platelet PLC-β2 isozyme. To identify the mechanisms leading to the defect, platelet RNA from the patient and healthy subjects was subjected to reverse transcription–polymerase chain reaction (RT-PCR) and the products sequenced. The PLC-β2 cDNA sequence in the patient showed no abnormalities. Platelet PLC-β2 and β-actin (internal control) mRNA levels were assessed by RT-PCR; the ratio of PLC-β2 to β-actin mRNA levels was 0.80 to 0.95 in 4 healthy subjects and 0.28 in the patient. PLC-β2 mRNA levels were similarly reduced compared with GPIIb and Gαq mRNA levels. PLC-γ2 and platelet factor 4 mRNA levels were normal. Calcium mobilization was studied in neutrophils upon activation with formyl-Met-Leu-Phe (fMLP), adenosine diphosphate (ADP), platelet-activating factor (PAF), interleukin-8 (IL-8), C5a, and leukotriene B4 (LTB4), and it was normal. Neutrophil elastase secretion upon activation with fMLP, ADP, PAF, IL-8, C5a, and LTB4 was normal, as were neutrophil PLC-β2 mRNA and PLC-β2 on immunoblotting. Thus, responses to activation, PLC-β2 protein, and PLC-β2 mRNA are decreased in patient platelets but not in neutrophils, providing evidence for a hitherto undescribed lineage (platelet)–specific defect in PLC-β2 gene expression. These studies provide a physiologically relevant model to delineate regulation of PLC-β2 gene and its tissue-specific expression.

Molecular, functional, and gene expression analysis of zebrafish hypoxia-inducible factor-3α

2012 ◽  
Vol 303 (11) ◽  
pp. R1165-R1174 ◽  
Author(s):  
Peng Zhang ◽  
Ling Lu ◽  
Qing Yao ◽  
Yun Li ◽  
Jianfeng Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Hypoxia Inducible Factor ◽  
Model Organism ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Specific Expression ◽  
Physiological Regulation ◽  
Functional Conservation

Hypoxia-inducible factors 1–3 (HIF1–3) are transcription factors that regulate gene expression in response to hypoxia. Compared with our extensive understanding of HIF-1 and HIF-2, our knowledge of HIF-3 is limited. In this study, we characterized the zebrafish hif-3α gene and determined its temporal and spatial expression, physiological regulation, and biological activity. We show that the chromosomal location, gene structure, and protein structure of zebrafish hif-3α are similar to its mammalian orthologs. When tagged with enhanced green fluorescent protein and transfected into cultured cells, zebrafish Hif-3α was localized in the nucleus and stimulated reporter gene expression in a hypoxia response element-dependent manner. During early development, hif-3α mRNA was detected in all tissues with higher levels in the head. This expression pattern became more apparent in larvae at the 72, 96, and 120 hours post fertilization stages. In the adult stage, hif-3α mRNA was detected in all examined tissues with the highest levels in the ovary. Hypoxia treatment increased Hif-3α protein levels in both embryos and adults. Hypoxia also increased hif-3α mRNA expression levels, and this regulation was tissue-specific. Expression of a stabilized form of Hif-1α in zebrafish embryos increased the expression of igfbp-1a, a Hif-1 target gene, whereas it did not change hif-3α mRNA levels, suggesting that hif-3α is not a Hif-1α target. These results provide new information about the structural and functional conservation, spatial and temporal expression, and physiological regulation of hif-3α in a teleost model organism.

scholarly journals Mitotane induces CYP3A4 expression via activation of the steroid and xenobiotic receptor

2012 ◽  
Vol 216 (3) ◽  
pp. 297-305 ◽  
Author(s):  
Akira Takeshita ◽  
Junko Igarashi-Migitaka ◽  
Noriyuki Koibuchi ◽  
Yasuhiro Takeuchi
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Drug Interactions ◽  
Luciferase Reporter ◽  
Pcr Analysis ◽  
Metabolic Clearance ◽  
Mrna Levels ◽  
Steroid And Xenobiotic Receptor ◽  
Cyp3a4 Enzyme ◽  
Xenobiotic Receptor

Adrenocortical carcinoma (ACC) is a rare disease with an extremely poor prognosis. Mitotane alone or in combination with other cytotoxic drugs is a common therapeutic option for ACC. In addition to its adrenolytic function, mitotane has been known for decades to increase the metabolic clearance of glucocorticoids. It was recently shown that the tyrosine kinase inhibitor sunitinib is also rapidly metabolized in patients treated with mitotane, indicating that mitotane engages in clinically relevant drug interactions. Although the precise mechanism of these interactions is not well understood, cytochrome P450 mono-oxygenase 3A4 (CYP3A4) is a key enzyme to inactivate both glucocorticoids and sunitinib. The nuclear receptor steroid and xenobiotic receptor (SXR (NR1I2)) is one of the key transcriptional regulators ofCYP3A4gene expression in the liver and intestine. A variety of xenobiotics bind to SXR and stimulate transcription of xenobiotic-response elements (XREs) located in theCYP3A4gene promoter. In this study, we evaluated the effects of mitotane on SXR-mediated transcriptionin vitroby luciferase reporter analysis, SXR–steroid receptor coactivator 1 (SRC1) interactions, quantitative real-time PCR analysis ofCYP3A4expression, SXR knockdown, and CYP3A4 enzyme activity assays using human hepatocyte-derived cells. We found that mitotane activated SXR-mediated transcription of the XREs. Mitotane recruited SRC1 to the ligand-binding domain of SXR. Mitotane increasedCYP3A4mRNA levels, which was attenuated by SXR knockdown. Finally, we showed that mitotane increased CYP3A4 enzyme activity. We conclude that mitotane can induceCYP3A4gene expression and suggest that mitotane is used cautiously due to its drug–drug interactions.

scholarly journals The Human β Globin Locus Introduced by YAC Transfer Exhibits a Specific and Reproducible Pattern of Developmental Regulation in Transgenic Mice

Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4602-4609 ◽  
Author(s):  
Susanna Porcu ◽  
Michael Kitamura ◽  
Ewa Witkowska ◽  
Zemin Zhang ◽  
Annick Mutero ◽  
...  
Keyword(s):  
Gene Expression ◽  
Developmental Regulation ◽  
Globin Gene ◽  
Regulatory Elements ◽  
Regulatory Sequences ◽  
Mrna Levels ◽  
Globin Genes ◽  
Globin Mrna ◽  
Specific Expression ◽  
Artificial Chromosomes

Abstract The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.

scholarly journals GEsture: an online hand-drawing tool for gene expression pattern search

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4927 ◽  
Author(s):  
Chunyan Wang ◽  
Yiqing Xu ◽  
Xuelin Wang ◽  
Li Zhang ◽  
Suyun Wei ◽  
...  
Keyword(s):  
Gene Expression ◽  
Time Series ◽  
Expression Pattern ◽  
Expression Patterns ◽  
Gene Expression Pattern ◽  
Pattern Search ◽  
Clustering Methods ◽  
Specific Expression ◽  
Time Series Gene Expression ◽  
Specific Expression Pattern

Gene expression profiling data provide useful information for the investigation of biological function and process. However, identifying a specific expression pattern from extensive time series gene expression data is not an easy task. Clustering, a popular method, is often used to classify similar expression genes, however, genes with a ‘desirable’ or ‘user-defined’ pattern cannot be efficiently detected by clustering methods. To address these limitations, we developed an online tool called GEsture. Users can draw, or graph a curve using a mouse instead of inputting abstract parameters of clustering methods. GEsture explores genes showing similar, opposite and time-delay expression patterns with a gene expression curve as input from time series datasets. We presented three examples that illustrate the capacity of GEsture in gene hunting while following users’ requirements. GEsture also provides visualization tools (such as expression pattern figure, heat map and correlation network) to display the searching results. The result outputs may provide useful information for researchers to understand the targets, function and biological processes of the involved genes.

scholarly journals Development of digestive enzymatic activity and gene expression during the early ontogeny of Chinese perch (Siniperca chuatsi)

2021 ◽  
Author(s):  
Shulin Tang ◽  
Xu-Fang Liang ◽  
Shan He ◽  
Yanpeng Zhang ◽  
Di Peng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Specific Activity ◽  
Digestive Enzyme ◽  
Digestive Enzyme Activity ◽  
Freshwater Species ◽  
Gene Expressions ◽  
Siniperca Chuatsi ◽  
Chinese Perch

Abstract Chinese perch (Siniperca chuatsi) is one of the economically important freshwater species fish for aquaculture in China. This study aimed to determine the ontogenetic development of the digestive enzyme activity (trypsin, pepsin, amylase, lipase, chymotrypsin and alkaline phosphatase) and related gene expressions of S. chuatsi larvae from hatching to 30 days post-hatching (dph). The larvae were fed with live fry fish twice a day. Results indicated that it was low detection of enzyme activity and gene expression of trypsin, chymotrypsin, lipase, amylase and alkaline phosphatase before mouth opened, the last two enzymes showed an activity close to zero. Different from other carnivorous fish, specific activity and gene expression of trypsin, chymotrypsin and lipase in S. chuatsi larvae were not increased after starting the first feeding. Interestingly, the amylase and alkaline phosphatase specific activity progressively increased over development, indicating that the larvae have certain ability to digest carbohydrates. Pepsin activity and gene expression started to sharply increase after 15 dph, other digestive enzyme activity showed downward trends. The development pattern of digestive enzymes may affect the ability of S. chuatsi to digest the zooplankton, which leads to the formation of unique feeding habit of the S. chuatsi larvae. This study also will provide the necessary theoretical basis for the artificial opening diet of the S. chuatsi larvae.

scholarly journals The Human β Globin Locus Introduced by YAC Transfer Exhibits a Specific and Reproducible Pattern of Developmental Regulation in Transgenic Mice

Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4602-4609 ◽  
Author(s):  
Susanna Porcu ◽  
Michael Kitamura ◽  
Ewa Witkowska ◽  
Zemin Zhang ◽  
Annick Mutero ◽  
...  
Keyword(s):  
Gene Expression ◽  
Developmental Regulation ◽  
Globin Gene ◽  
Regulatory Elements ◽  
Regulatory Sequences ◽  
Mrna Levels ◽  
Globin Genes ◽  
Globin Mrna ◽  
Specific Expression ◽  
Artificial Chromosomes

The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.

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