scholarly journals Bile acids via FXR initiate the expression of major transporters involved in the enterohepatic circulation of bile acids in newborn mice

2012 ◽  
Vol 302 (9) ◽  
pp. G979-G996 ◽  
Author(s):  
Julia Yue Cui ◽  
Lauren M. Aleksunes ◽  
Yuji Tanaka ◽  
Zidong Donna Fu ◽  
Ying Guo ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Bile Acids ◽  
Messenger Rna ◽  
Mouse Liver ◽  
Enterohepatic Circulation ◽  
Lipid Absorption ◽  
Newborn Mouse ◽  
Mrna Levels ◽  
Newborn Mice ◽  
Classic Pathway

The enterohepatic circulation (EHC) of bile acids (BAs) plays a pivotal role in facilitating lipid absorption. Therefore, initiation of the EHC in newborns is of crucial importance for lipid absorption from milk. The purpose of this study was to determine at what age BA transporters in liver are expressed, and the mechanism for their initiation. Serum and liver samples were collected from C57BL/6 mice at 2 days before birth and various postnatal ages. Messenger RNA assays revealed a dramatic increase at birth in the expression of the BA transporters (Ntcp, Bsep, Mrp4, Ostβ), as well as the phospholipid floppase Mdr2 in mouse liver, with the highest expression at 1 day of age. The mRNA expression of the ileal BA transporters (Ostα and Ostβ) also markedly increased at birth. Meanwhile, taurine-conjugated cholic acid markedly increased in both serum and liver of newborns, correlated with upregulation of the classic pathway of BA biosynthesis in newborn liver. The mRNA levels of the major BA sensors, FXR and PXR, were increased at 1 day of age, and their prototypical target genes were upregulated in liver. The mRNA expression of transporters involved in the EHC of BAs was similar in wild-type and PXR-null mice. In contrast, in FXR-null mice, the “ day 1 surge” pattern of Ntcp, Bsep, Ostβ, and Mdr2 was blocked in newborn mouse liver, and the induction of Ostα and Ostβ was also abolished in ileums of FXR-null mice. In conclusion, at birth, BAs from the classic pathway of synthesis trigger the induction of transporters involved in EHC of BAs in mice, through activation of the nuclear receptor FXR.

Bile Acids: The Good, the Bad, and the Ugly

Physiology ◽  
1999 ◽  
Vol 14 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Alan F. Hofmann
Keyword(s):  
Bile Acids ◽  
Enterohepatic Circulation ◽  
Cholesterol Metabolism ◽  
Plasma Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipid Absorption ◽  
Bile Acid Metabolism ◽  
Cholesterol Levels ◽  
Density Lipoprotein Receptor

Bile acids, amphipathic end products of cholesterol metabolism, are “good” in the infant because they enhance lipid absorption and thereby promote growth. Bile acids also induce bile flow and biliary lipid secretion. The enterohepatic circulation of bile acids is “bad” in the adult because it downregulates hepatocyte low-density lipoprotein receptor activity and thereby elevates plasma cholesterol levels. Defects in bile acid metabolism such as impaired biosynthesis or transport are “ugly” because they cause morbidity and death. New approaches for treating these defects are being developed.

scholarly journals Obesity May Provide Pro-ILC3 Development Inflammatory Environment in Asthmatic Children

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yumin Wu ◽  
Jiawei Yue ◽  
Juncheng Wu ◽  
Wei Zhou ◽  
Dapeng Li ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Messenger Rna ◽  
Mrna Level ◽  
Asthma Severity ◽  
Lymphoid Cells ◽  
Mrna Levels ◽  
Asthmatic Children ◽  
Prevalence Of Obesity ◽  
Elevated Frequency ◽  
Relative Mrna Expression

The prevalence of obesity in children has dramatically increased in the last few decades, and obesity has also emerged as an important risk factor for asthma. Innate mechanisms have been shown to be involved in both diseases, particularly through the recently described innate lymphoid cells (ILCs), in which ILC3s have been linked to obesity both in human and in murine models. The aim of this study was to explore whether being overweight in asthmatic children was associated with elevated circulating ILC3 or elevated messenger RNA (mRNA) levels of RORC, IL-17A, and IL-22. Our results showed significantly elevated ILC3 frequencies in overweight asthmatic children compared with nonoverweight controls based on the detection of Lin+CD127+IL-23R+ cells by flow cytometry. Moreover, elevated ILC3 frequencies positively correlated with the mRNA expression of RORC which has been identified as a transcription factor of ILC3s. The relative mRNA expression level of IL-17A was also upregulated in overweight compared to nonoverweight children, as was the relative mRNA level of IL-22. However, there were no correlations between ILC3 frequencies or the expressions of RORC, IL-17A, and IL-22 and asthma severity. These results suggested that childhood obesity is an independent factor that is associated with an elevated frequency of circulating ILC3s and higher expressions of RORC, IL-22, and IL-17A.

scholarly journals Adapted approach to profile genes while reconciling Vegf-a mRNA expression in the developing and injured lung

2015 ◽  
Vol 308 (12) ◽  
pp. L1202-L1211 ◽  
Author(s):  
Daniel D. Lee ◽  
Margaret A. Schwarz
Keyword(s):  
Messenger Rna ◽  
Housekeeping Genes ◽  
Newborn Mouse ◽  
Mrna Levels ◽  
Developmental Studies ◽  
Rna Integrity ◽  
Amplicon Length ◽  
Highly Sensitive ◽  
Injured Lung ◽  
Mouse Lungs

During lung development and injury, messenger RNA (mRNA) transcript levels of genes fluctuate over both space and time. Quantitative PCR (qPCR) is a highly sensitive, widely used technique to measure the mRNA levels. The sensitivity of this technique can be disadvantageous and errors amplified when each qPCR assay is not validated. In contrast to other organs, lungs have high RNase activity, resulting in less than optimal RNA integrity. We implemented a strategy to address these limitations in developing and injured lungs. Parameters were established and a filter designed that optimized amplicon length and included or excluded samples based on RNA integrity. This approach was illustrated and validated by measuring mRNA levels including Vegf-a in newborn mouse lungs that were injured by 85% oxygen (hyperoxia) for 12 days and compared with control (normoxia). We demonstrate that, in contrast to contradictory Vegf-a expression when normalized to the least suitable housekeeping genes, application of this filter and normalization to most suitable three housekeeping genes, Hprt, Eef2, and Rpl13a, gave reproducible Vegf-a expression, thus corroborating the sample filter. Accordingly, both short amplicon length and proper normalization to ranked, evaluated genes minimized erroneous fluctuation and qPCR amplification issues associated with nonideal RNA integrity in injured and developing lungs. Furthermore, our work uncovers how RNA integrity, purity, amplicon length, and discovery of stable candidate reference genes enhance precision of qPCR results and utilizes the advantages of qPCR in developmental studies.

The influence of salinity and ammonium levels on amoA mRNA expression of ammonia-oxidizing prokaryotes

2012 ◽  
Vol 65 (12) ◽  
pp. 2228-2235 ◽  
Author(s):  
T. Fukushima ◽  
Y. J. Wu ◽  
L. M. Whang
Keyword(s):  
Mrna Expression ◽  
Messenger Rna ◽  
Rflp Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
Mrna Levels ◽  
Transcriptional Responses ◽  
Stirred Tank Reactors ◽  
Salinity Levels ◽  
Continuous Stirred Tank ◽  
Polymerase Chain

This study investigated the influence of salinity and ammonium levels on ammonia-oxidizing bacteria (AOB) and archaea (AOA) by monitoring their amo subunit A (amoA) messenger RNA (mRNA) expression. The aerobic mini-continuous stirred-tank reactors (mini-CSTRs) were operated for 48 h under different salinity or ammonium levels. Quantification of archaeal and bacterial amoA mRNA levels using real-time reverse transcription polymerase chain reaction, combined with terminal restriction fragment length polymorphism (T-RFLP) analysis, was applied to investigate the differential transcriptional responses among AOA species. High salinity levels repressed both archaeal and bacterial amoA mRNA expressions. On the other hand, high ammonium levels repressed only archaeal mRNA expression, suggesting that ammonium is a significant environmental factor shaping abundance of AOA and AOB. T-RFLP results indicated that the impacts of salinity and ammonium levels were different among AOA species. Although further study is necessary to add significance to our findings, the combination of the short-term mini-CSTR operations and amoA mRNA-based analyses allow a preliminary study on the influences of environmental factors on competition between the AOA and AOB communities.

Dynamic Alterations in the Expression of P2Y12 Receptor but Not COX-1 in Platelets from Streptozocin-Induced Diabetic Rats.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2638-2638
Author(s):  
Chi Chen ◽  
Zili He ◽  
Candice Ruby ◽  
Waqas Arslan ◽  
Madhumati Kalavar ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Messenger Rna ◽  
Early Stage ◽  
Diabetic Rats ◽  
Dense Granule ◽  
Receptor Expression ◽  
P2y12 Receptor ◽  
Mrna Levels ◽  
Cyclooxygenase 1 ◽  
Cox 1

Abstract In patients or animals with established diabetes mellitus, platelets have been shown to be hyperreactive to ADP. This alteration of the platelet function occurs independent of activation of the arachidonate pathway or release of dense granule contents. In the present study, we examined the expression of the platelet ADP-binding receptor, P2Y12, in early stage of streptozocin(STZ)-induced diabetes in rats. Platelet messenger RNA (mRNA) levels for P2Y12 and cyclooxygenase-1 (COX-1) were determined by comparative RT-PCR in 7 control rats on day 0, 6 diabetic rats each on days 2, 3, 4, and 4 diabetic rats on day 7 after intraperitoneal injection of streptozocin (50 mg/kg). The plasma glucose level was 406 ± 10 mg/dl in diabetic rats, significantly greater than 151 ± 12 mg/dl in control rats. After induction of diabetes, the expression of P2Y12 mRNA significantly decreased to 76 ± 9% of the level of control on day 2, 54 ± 6% of control on day 3, reached a nadir of 28 ± 6% of control on day 4, and rose to 43 ± 10% of control on day 7. These dynamic changes of P2Y12 mRNA in platelets reflected the expression of P2Y12 mRNA in megakaryocytes isolated to a high state of purity (>96 %) from rat bone marrow. Specifically, the megakaryocytic P2Y12 mRNA expression in the diabetic rats on days 1, 2 and 3 were 74 ± 8 %, 93 ± 1%, and 117 ± 6% of those in control rats, respectively. Treatment of diabetic rats with insulin reduced the trend of decline in the platelet P2Y12 expression. By contrast, the platelet COX-1 mRNA expression measured on days 2, 3, 4 and 7 after the induction of diabetes was similar to that in the control rats. These results in diabetic rats demonstrate dynamic alterations of the mRNA expression of megakaryocyte-platelet P2Y12, but not of COX-1. The decrease in the P2Y12 receptor expression in early stage of STZ-induced diabetes may serve to attenuate the hyperaggregability of platelets and reduce the risk of vascular thrombosis.

The in vivo kinetics of tissue factor messenger RNA expression during human endotoxemia: relationship with activation of coagulation

Blood ◽  
2000 ◽  
Vol 96 (2) ◽  
pp. 554-559 ◽  
Author(s):  
Rendrik F. Franco ◽  
Evert de Jonge ◽  
Pascale E. P. Dekkers ◽  
Janneke J. Timmerman ◽  
C. Arnold Spek ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Tissue Factor ◽  
Messenger Rna ◽  
Thrombin Generation ◽  
Mrna Levels ◽  
Total Blood ◽  
Human Endotoxemia ◽  
Lps Challenge ◽  
Kinetics Of

Abstract Triggering of the tissue factor (TF)-dependent coagulation pathway is considered to underlie the generation of a procoagulant state during endotoxemia. To determine the in vivo pattern of monocytic TF messenger RNA (mRNA) expression during endotoxemia, 10 healthy volunteers were injected with lipopolysaccharide (LPS, 4 ng/kg) and blood was collected before and 0.5, 1, 2, 3, 4, 6, 8, and 24 hours after LPS administration. Total blood RNA was isolated and amplified by NASBA (nucleic acid sequence-based amplification), followed by quantitation of TF mRNA by an electrochemiluminescence (ECL) assay. To compare the pattern of coagulation activation with the kinetics of monocytic TF mRNA expression, we measured plasma levels of markers of thrombin generation, thrombin-antithrombin (TAT) complexes, and prothrombin fragment 1 + 2 (F1 + 2). Baseline value (mean ± SEM) of the number of TF mRNA molecules per monocytic cell was 0.08 ± 0.02. A progressive and significant (P < .0001) increase in TF expression was observed after LPS injection (+0.5 hour: 0.3 ± 0.1, +1 hour: 1.3 ± 0.9, +2 hours: 4.1 ± 0.9), peaking at +3 hours (10 ± 1.9 TF mRNA molecules per monocyte). As TF mRNA levels increased, thrombin generation was augmented. Peak levels of TAT and F1 + 2 were reached later (at t +4 hours) than those of TF mRNA. TF mRNA, TAT, and F1 + 2 levels returned to baseline after 24 hours. In conclusion, we used a NASBA/ECL-based technique to quantify TF mRNA in whole blood during human endotoxemia and observed a 125-fold increase in TF mRNA levels. Our data demonstrate a pivotal role for enhanced TF gene activity in the activation of coagulation after LPS challenge.

scholarly journals Regulation of Corticotropin-Releasing Factor Receptor Type 2β Messenger Ribonucleic Acid in the Rat Cardiovascular System by Urocortin, Glucocorticoids, and Cytokines*

Endocrinology ◽  
2000 ◽  
Vol 141 (7) ◽  
pp. 2285-2293 ◽  
Author(s):  
Kazunori Kageyama ◽  
Georges E. Gaudriault ◽  
Margaret J. Bradbury ◽  
Wylie W. Vale
Keyword(s):  
Cardiovascular System ◽  
Mrna Expression ◽  
Messenger Rna ◽  
Physical Restraint ◽  
Receptor Type ◽  
Mrna Levels ◽  
Immune Challenge ◽  
Messenger Ribonucleic Acid

CRF receptor type 2 (CRF R2) messenger RNA (mRNA) expression in the rodent heart is modulated by exposure to both the bacterial endotoxin lipopolysaccharide (LPS) and glucocorticoids. In this study we examined the roles of glucocorticoids, cytokines, and CRF R2β ligands in the regulation of CRF R2β expression in the cardiovascular system both in vivo and in vitro. Using ribonuclease protection assays, we found that, in addition to the injection of LPS or corticosterone, physical restraint caused a decrease in CRF R2β mRNA levels in the rat heart and aorta. Adrenalectomy with corticosterone replacement at constant levels partially blocked LPS-induced decreases in CRF R2β mRNA expression in the heart. Thus, elevations of endogenous circulating corticosterone could contribute to the down-regulation of CRF R2β mRNA expression in heart. To identify other putative modulating factors, we examined CRF R2β expression in the aorta- derived A7R5 cell line. Incubation with CRF R2 ligands or dexamethasone reduced CRF R2β mRNA levels. In addition, incubation with a variety of cytokines, proteins released during immune challenge, also reduced CRF R2β mRNA expression. The multifactorial regulation of CRF R2β mRNA expression in the cardiovascular system may serve to limit the inotropic and chronotropic effects of CRF R2 agonists such as urocortin during prolonged physical or immune challenge.

In vivo and in vitro effects of pentavalent antimony on mouse liver cytochrome P450s

2016 ◽  
Vol 36 (1) ◽  
pp. 33-41 ◽  
Author(s):  
DR Coelho ◽  
ACAX De-Oliveira ◽  
TEM Parente ◽  
BS Leal ◽  
LF das Chagas ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Mouse Liver ◽  
Liver Microsomes ◽  
Mrna Levels ◽  
Intact Cells ◽  
Cyp1a Activity ◽  
In Vitro Effects ◽  
Catalyzed Reactions

Pentavalent antimonial (Sb5+) drugs such as meglumine antimoniate (MA) are the mainstay treatment of leishmaniases in developing countries. The effects of these compounds on drug-metabolizing enzymes have not been characterized and their potential pharmacokinetic interactions with other drugs are therefore unknown. The present study investigated whether treatment with MA (300 mg Sb5+/kg body weight/day, subcutaneously) for 24 days affected the activities of cytochrome P450 (CYP)1A (ethoxyresorufin- O-deethylase), CYP2A5 (coumarin 7-hydroxylase), CYP2E1 ( p-nitrophenol-hydroxylase), CYP2B9/10 (benzyloxy-resorufin- O-debenzylase), or CYP3A11 (erythromycin- N-demethylase) in the livers of Swiss Webster (SW) and DBA-2 male and female mice. The results showed that CYP2A5-, CYP2E1-, and CYP3A11-catalyzed reactions were unaffected by MA treatment. A decrease in CYP2B9/10 activity was noted in DBA-2 females (but not males) and was not observed in SW males or females. However, repeated MA administration reduced mouse liver CYP1A activity. CYP1A2 messenger RNA (mRNA) levels were not affected by MA and in vitro exposure of mouse liver microsomes to Sb3+ and Sb5+ did not reduce CYP1A activity. These findings suggested that in vivo treatment with Sb5+ drugs depressed CYP1A activity, without downregulating CYP1A2 mRNA expression. Since in vitro treatment of liver microsomes failed to inhibit CYP1A activity, this effect may require intact cells.

The Effect Orthosilicic Acid on Collagen Type I, Alkaline Phosphatase and Osteocalcin mRNA Expression in Human Bone-Derived Osteoblasts In Vitro

2006 ◽  
Vol 309-311 ◽  
pp. 121-124 ◽  
Author(s):  
Meera Q. Arumugam ◽  
D.C. Ireland ◽  
Roger A. Brooks ◽  
Neil Rushton ◽  
William Bonfield
Keyword(s):  
Alkaline Phosphatase ◽  
Mrna Expression ◽  
Messenger Rna ◽  
Collagen Type ◽  
Collagen Type I ◽  
Orthosilicic Acid ◽  
Type I ◽  
Mrna Levels ◽  
Polymerase Chain

The object of this study was to investigate the effect of the concentration of orthosilicic acid (0, 0.5, 1, 5 and 10µM) on gene expression in human osteoblast cells isolated from trabecular bone. This was measured using reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify messenger RNA (mRNA) levels for collagen type I, alkaline phosphatase and osteocalcin. Results showed that while collagen type I mRNA expression was increased by the addition of up to 10µM orthosilicic acid, ALP message was suppressed over time and osteocalcin levels were decreased.

scholarly journals Developmental regulation of mRNA species for types II, IX and XI collagens during mouse embryogenesis

1997 ◽  
Vol 324 (1) ◽  
pp. 209-216 ◽  
Author(s):  
Merja PERÄLÄ ◽  
Mikko SAVONTAUS ◽  
Marjo METSÄRANTA ◽  
Eero VUORIO
Keyword(s):  
Developmental Regulation ◽  
Northern Analysis ◽  
Cdna Clones ◽  
Newborn Mouse ◽  
Mrna Levels ◽  
Mouse Development ◽  
Rnase Protection ◽  
Newborn Mice ◽  
Mrna Species ◽  
Collagen Mrna

Several techniques were used to study the co-ordination of mRNA levels for five constituent chains of cartilage collagen fibrils during mouse development. Short cDNA clones were first constructed for mouse and human α3(IX) and for mouse proα1(XI) collagen mRNA species. Northern analysis of developing mouse embryos revealed that the mRNA species for α1, α2 and α3 chains of type IX collagen peaked earlier than those for proα1(II) and proα1(XI) collagen chains. Quantification of these mRNA species by slot-blot hybridization confirmed this developmental regulation: the mRNA ratios for type II/type IX/type XI collagens changed from 5.7:1:0.6 (at embryonic day 12.5) to 10.6:1:0.9 (in newborn mice). However, the genes coding for the three chains of type IX collagen seemed to be under more co-ordinated regulation during mouse development. In addition to high mRNA levels in cartilages and the eye, low levels of type IX collagen transcripts were identified in brain and skin of newborn mouse using RNase protection and reverse transcriptase–PCR assays. Finally, hybridization in situ revealed identical tissue distributions of the three type IX collagen mRNA species during early chondrogenesis but somewhat more widespread expression of the α1(IX) and α3(IX) mRNA species during endochondral ossification at day 16.5 of embryonic development. These results suggest a relatively tight co-ordination of the α1(IX), α2(IX), and α3(IX) collagen mRNA species in chondrocytes, but a lack of co-ordination in several non-cartilaginous tissues.

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