scholarly journals Tissue-specific gene expression in mouse hepatocytes cultured in growth-restricting medium.

1988 ◽  
Vol 8 (8) ◽  
pp. 3338-3344 ◽  
Author(s):  
T Spiegelberg ◽  
J O Bishop
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Mrna Level ◽  
Alpha Fetoprotein ◽  
Apolipoprotein A1 ◽  
Specific Gene ◽  
Mrna Levels ◽  
Hormonal Stimulation ◽  
Tissue Specific

Culture conditions which maintain hepatocytes in their in vivo state are not known. This hampers the study of liver gene expression and of direct responses of liver genes to hormonal stimulation. We argued that hepatocytes that were unable to divide might retain in vivo characteristics. We therefore plated mouse (BALB/c) hepatocytes on plastic dishes in medium lacking arginine and measured the levels and transcription rates of six tissue-specific mRNAs over a period of days. Alpha-fetoprotein mRNA began to accumulate at about 48 h of culture, and transcription could sometimes be detected after 72 h. The levels and transcription rates of four mRNAs (albumin, alpha-1-antitrypsin, apolipoprotein A1, and major urinary protein [MUP]) fell sharply. The rate of transcription of transferrin mRNA fell less rapidly, and its level remained high, partly due to its longer half-life. The overall pattern of gene expression in the plated cells did not exactly parallel that of either fetal or regenerating liver. The hepatocytes remained responsive to hormonal stimulation. Insulin and dexamethasone each tended to counteract changes in mRNA levels, for example, preventing the accumulation of alpha-fetoprotein mRNA. The effects of insulin were primarily due to changes in transcription rates. Bovine growth hormone and thyroxine elevated the levels of most of the mRNAs. Many of the effects of these hormones, when added singly, could not be ascribed to changes in transcription. The level of MUP mRNA was strongly affected by added hormones. The mRNA level at 5 days was increased by added insulin, dexamethasone, growth hormone, and thyroxine. In the presence of these three hormones, the decay in the transcription rate of the MUP genes was reduced about 10-fold. We conclude that hepatocytes plated under these nongrowing conditions can provide insights into the hormonal responsiveness of tissue-specific genes.

Tissue-specific gene expression in mouse hepatocytes cultured in growth-restricting medium

1988 ◽  
Vol 8 (8) ◽  
pp. 3338-3344
Author(s):  
T Spiegelberg ◽  
J O Bishop
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Mrna Level ◽  
Alpha Fetoprotein ◽  
Apolipoprotein A1 ◽  
Specific Gene ◽  
Mrna Levels ◽  
Hormonal Stimulation ◽  
Tissue Specific

Culture conditions which maintain hepatocytes in their in vivo state are not known. This hampers the study of liver gene expression and of direct responses of liver genes to hormonal stimulation. We argued that hepatocytes that were unable to divide might retain in vivo characteristics. We therefore plated mouse (BALB/c) hepatocytes on plastic dishes in medium lacking arginine and measured the levels and transcription rates of six tissue-specific mRNAs over a period of days. Alpha-fetoprotein mRNA began to accumulate at about 48 h of culture, and transcription could sometimes be detected after 72 h. The levels and transcription rates of four mRNAs (albumin, alpha-1-antitrypsin, apolipoprotein A1, and major urinary protein [MUP]) fell sharply. The rate of transcription of transferrin mRNA fell less rapidly, and its level remained high, partly due to its longer half-life. The overall pattern of gene expression in the plated cells did not exactly parallel that of either fetal or regenerating liver. The hepatocytes remained responsive to hormonal stimulation. Insulin and dexamethasone each tended to counteract changes in mRNA levels, for example, preventing the accumulation of alpha-fetoprotein mRNA. The effects of insulin were primarily due to changes in transcription rates. Bovine growth hormone and thyroxine elevated the levels of most of the mRNAs. Many of the effects of these hormones, when added singly, could not be ascribed to changes in transcription. The level of MUP mRNA was strongly affected by added hormones. The mRNA level at 5 days was increased by added insulin, dexamethasone, growth hormone, and thyroxine. In the presence of these three hormones, the decay in the transcription rate of the MUP genes was reduced about 10-fold. We conclude that hepatocytes plated under these nongrowing conditions can provide insights into the hormonal responsiveness of tissue-specific genes.

Characterization of Tissue-Specific HIF-1 and HIF-2 Regulatory Elements of the Erythropoietin Gene

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4763-4763
Author(s):  
Donghoon Yoon ◽  
Hyojin Kim ◽  
Minyoung Jang ◽  
Jihyun Song ◽  
Gregory E Arnold ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Specific Binding ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Mrna Levels ◽  
Specific Element ◽  
Α Subunit ◽  
Tissue Specific

Abstract Hypoxia regulates erythropoiesis and other essential processes via hypoxia-inducible transcription factors (HIFs). HIFs are heterodimers that consist of an α subunit (3 isotypes with significant homology; HIF-1α, HIF-2α, HIF-3α), and a common b-subunit; HIF-1 and HIF-2, in some instances exhibiting tissue- and gene-specific gene regulation. Erythropoietin (EPO) was the first identified HIF-1 target gene with the defined HIF-1 binding sequence. However, subsequent works suggested that HIF-2 also regulates EPO transcription and that there are other regulatory elements of EPO gene (i.e. Kidney Inducible Element KIE, Negative Regulatory Element NRE, and Negative Regulatory Liver specific Element NRLE). In silico analysis of the human EPO genome found two additional potential HIF-binding elements in the KIE and NRE regions. The comparative analysis of phylogenically conserved sequences of human, mouse, dog, and rat Epo genes further refined these mouse Epo gene HIF-binding elements as mKIE, mNRE1, mNRE2, and mNRLE2. We treated mice in hypoxia chamber (8% O2) and monitored changes of Epo mRNA levels in liver, kidney, brain, spleen, and bone marrow. All tested tissues increased Epo transcription during hypoxia. Bone marrow, spleen, kidney, and brain showed a peak of induction of Epo transcript at 3 hours of hypoxia treatment, while liver reached the highest level at 6 hours. Mice were sacrificed and organs were harvested, and in vivo chromatin immunoprecipitation (ChIPs) was performed with antibodies against HIF-1α and HIF- 2α and tissue-specific binding regions were defined. The results from these studies are summarized below. HIF-1 mKIE rnNRE mNRE2 mNRLE2 Norm Hyp Norm Hyp Norm Hyp Norm Hyp Liver − + − − + − ? ? Kidney − + − − + − + − Brain − + − − − + − + BM − + − − − − − + Splsen − + − − − − − + HIF-2 mKIE mNRE mNRE2 mNRLE2 Norm Hyp Norm Hyp Norm Hyp Norm Hyp “+” denotes presence and “-” absence of binding of HIF-1 and HIF-2, “?” – indicates inconclusive results. “Norm” - normoxia, “Hyp” - hypoxia. Liver − + − − − + − + Kidney + − − − + − ? ? Brain − − − − − − − + BM − − − − − − + − Spleen − + − − − − − + In conclusion, we demonstrate the differential hypoxia-induced binding of HIF-1 and HIF-2 at different HIF binding elements in the tissues known to express Epo. Further studies will be required to define the function of these HIF-1 and HIF-2 binding elements in tissue specific Epo expression and their role in health and disease.

scholarly journals Inherited Chromosomally Integrated Human Herpesvirus 6 Demonstrates Tissue-Specific RNA Expression In Vivo That Correlates with an Increased Antibody Immune Response

2019 ◽  
Vol 94 (1) ◽  
Author(s):  
Vikas Peddu ◽  
Isabelle Dubuc ◽  
Annie Gravel ◽  
Hong Xie ◽  
Meei-Li Huang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Specific Antibody ◽  
Human Herpesvirus ◽  
Specific Gene ◽  
Specific Antibody Response ◽  
Tissue Specific ◽  
Tissue Specific Gene ◽  
Specific Gene Expression ◽  
Human Herpesviruses

ABSTRACT Human herpesviruses 6A and 6B (HHV-6A and HHV-6B) are human viruses capable of chromosomal integration. Approximately 1% of the human population carries one copy of HHV-6A/B integrated into every cell in their body, referred to as inherited chromosomally integrated human herpesvirus 6A/B (iciHHV-6A/B). Whether iciHHV-6A/B is transcriptionally active in vivo and how it shapes the immunological response are still unclear. In this study, we screened DNA sequencing (DNA-seq) and transcriptome sequencing (RNA-seq) data for 650 individuals available through the Genotype-Tissue Expression (GTEx) project and identified 2 iciHHV-6A- and 4 iciHHV-6B-positive candidates. When corresponding tissue-specific gene expression signatures were analyzed, low levels HHV-6A/B gene expression was found across multiple tissues, with the highest levels of gene expression in the brain (specifically for HHV-6A), testis, esophagus, and adrenal gland. U90 and U100 were the most highly expressed HHV-6 genes in both iciHHV-6A- and iciHHV-6B-positive individuals. To assess whether tissue-specific gene expression from iciHHV-6A/B influences the immune response, a cohort of 15,498 subjects was screened and 85 iciHHV-6A/B+ subjects were identified. Plasma samples from iciHHV-6A/B+ and age- and sex-matched controls were analyzed for antibodies to control antigens (cytomegalovirus [CMV], Epstein-Barr virus [EBV], and influenza virus [FLU]) or HHV-6A/B antigens. Our results indicate that iciHHV-6A/B+ subjects have significantly more antibodies against the U90 gene product (IE1) than do non-iciHHV-6-positive individuals. Antibody responses against EBV and FLU antigens or HHV-6A/B gene products either not expressed or expressed at low levels, such as U47, U57, and U72, were identical between controls and iciHHV-6A/B+ subjects. CMV-seropositive individuals with iciHHV-6A/B+ have more antibodies against CMV pp150 than do CMV-seropositive controls. These results argue that spontaneous gene expression from integrated HHV-6A/B leads to an increase in antigenic burden that translates into a more robust HHV-6A/B-specific antibody response. IMPORTANCE HHV-6A and -6B are human herpesviruses that have the unique property of being able to integrate into the telomeric regions of human chromosomes. Approximately 1% of the world’s population carries integrated HHV-6A/B genome in every cell of their body. Whether viral genes are transcriptionally active in these individuals is unclear. By taking advantage of a unique tissue-specific gene expression data set, we showed that the majority of tissues from iciHHV-6 individuals do not show HHV-6 gene expression. Brain and testes showed the highest tissue-specific expression of HHV-6 genes in two separate data sets. Two HHV-6 genes, U90 (immediate early 1 protein) and U100 (glycoproteins Q1 and Q2), were found to be selectively and consistently expressed across several human tissues. Expression of U90 translates into an increase in antigen-specific antibody response in iciHHV-6A/B+ subjects relative to controls. Future studies will be needed to determine the mechanism of gene expression, the effects of these genes on human gene transcription networks, and the pathophysiological impact of having increased viral protein expression in tissue in conjunction with increased antigen-specific antibody production.

scholarly journals Effects of ketoacidosis on rat apolipoprotein A1 gene expression: a link with acidosis but not with ketones

2000 ◽  
Vol 25 (1) ◽  
pp. 129-139 ◽  
Author(s):  
MJ Haas ◽  
K Pun ◽  
D Reinacher ◽  
NC Wong ◽  
AD Mooradian
Keyword(s):  
Gene Expression ◽  
Promoter Activity ◽  
Simian Virus ◽  
Diabetic Rats ◽  
Apolipoprotein A1 ◽  
Mrna Levels ◽  
Hep G2 ◽  
Apoa1 Gene ◽  
Wide Range

To determine if ketoacidosis contributes to reduced apolipoprotein A1 (apoA1) expression in insulin-deficient diabetic rats, we examined the regulation of apoA1 gene expression in response to changes in ambient pH or ketone body concentrations. Hepatic apoAI mRNA levels were reduced 42% in diabetic rats relative to nondiabetic controls (means+/-s.d.; 321.8+/-43.7 vs 438.7+/-58.8 arbitrary units; P<0.03). Neither endogenous apoA1 mRNA nor transcriptional activity of the rat apoA1 gene promoter (from -474 to -7) were altered by sodium butyrate or isobutyramide (0.3 mM to 10 mM) in Hep G2 or Caco-2 cells. Rat hepatic and intestinal apoA1 mRNA levels, and plasma apoA1 concentration, were not altered 24 h after isobutyramide administration (500 mg/kg by gavage). When the effect of altering ambient pH within a wide range commonly encountered in vivo was studied, acidosis (pH 6.7), relative to alkalosis (pH 7.9), decreased apoAI mRNA levels relative to glyceraldehyde-3-phosphate dehydrogenase mRNA by 47% in Hep G2 cells (P<0.025) and by 24% in Caco-2 cells (P<0.017). Acidosis did not alter cytomegalo virus (CMV)-beta-galactosidase activity, or the activity of the simian virus (SV40) early-region promoter, in either cell line transfected with the respective constructs. The lowering of ambient pH was associated with a graded reduction in apoAI promoter activity. At pH 6.7, apoAI promoter activity was reduced by 75% compared with promoter activity at pH 7.9. These observations indicate that acidosis, but not ketosis, contributes to the reduction in apoA1 expression during diabetic ketoacidosis by down-regulating apoAI promoter activity.

scholarly journals GATA and Nkx factors synergistically regulate tissue-specific gene expression and development in vivo

Development ◽  
2007 ◽  
Vol 134 (1) ◽  
pp. 189-198 ◽  
Author(s):  
Y. Zhang ◽  
N. Rath ◽  
S. Hannenhalli ◽  
Z. Wang ◽  
T. Cappola ◽  
...  
Keyword(s):  
Gene Expression ◽  
Specific Gene ◽  
Tissue Specific ◽  
Tissue Specific Gene ◽  
Specific Gene Expression

scholarly journals Real time, in vivo measurement of neuronal and peripheral clocks in Drosophila melanogaster

2022 ◽  
Author(s):  
Peter S Johnstone ◽  
Maite Ogueta ◽  
Inan Top ◽  
Sheyum Syed ◽  
Ralf Stanewsky ◽  
...  
Keyword(s):  
Gene Expression ◽  
Real Time ◽  
Circadian Clocks ◽  
Specific Gene ◽  
Tissue Specific ◽  
In Vivo Measurement ◽  
Neuronal Tissues ◽  
Peripheral Clocks ◽  
The Brain

Circadian clocks are highly conserved transcriptional regulators that control 24-hour oscillations in gene expression, physiological function, and behavior. Circadian clocks exist in almost every tissue and are thought to control tissue-specific gene expression and function, synchronized by the brain clock. Many disease states are associated with loss of circadian regulation. How and when circadian clocks fail during pathogenesis remains largely unknown because it is currently difficult to monitor tissue-specific clock function in intact organisms. Here, we developed a method to directly measure the transcriptional oscillation of distinct neuronal and peripheral clocks in live, intact Drosophila, which we term Locally Activatable BioLuminescence or LABL. Using this method, we observed that specific neuronal and peripheral clocks exhibit distinct transcription properties. Loss of the receptor for PDF, a circadian neurotransmitter critical for the function of the brain clock, disrupts circadian locomotor activity but not all tissue-specific circadian clocks; we found that, while peripheral clocks in non-neuronal tissues were less stable after the loss of PDF signaling, they continued to oscillate. This result suggests that the presumed dominance of the brain clock in regulating peripheral clocks needs to be re-examined. This result further demonstrates that LABL allows rapid, affordable, and direct real-time monitoring of clocks in vivo.

Time- and dose-related effects of gonadotropin-releasing hormone on growth hormone and gonadotropin subunit gene expression in the goldfish pituitary

2002 ◽  
Vol 80 (9) ◽  
pp. 915-924 ◽  
Author(s):  
Christian Klausen ◽  
John P Chang ◽  
Hamid R Habibi
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Molecular Forms ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Induced Responses ◽  
Releasing Hormone ◽  
Significant Difference

The goldfish brain contains two molecular forms of gonadotropin-releasing hormone (GnRH): salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II). In a preliminary report, we demonstrated the stimulation of gonadotropin hormone (GtH) subunit and growth hormone (GH) mRNA levels by a single dose of GnRH at a single time point in the goldfish pituitary. Here we extend the work and demonstrate time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH gene expression in vivo and in vitro. The present study demonstrates important differences between the time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH mRNA levels. Using primary cultures of dispersed pituitary cells, the minimal effective dose of cGnRH-II required to stimulate GtH subunit mRNA levels was found to be 10-fold lower than that of sGnRH. In addition, the magnitudes of the increases in GtH subunit and GH mRNA levels stimulated by cGnRH-II were found to be higher than the sGnRH-induced responses. However, no significant difference was observed between sGnRH and cGnRH-II-induced responses in vivo. Time-related studies also revealed significant differences between sGnRH- and cGnRH-II-induced production of GtH subunit and GH mRNA in the goldfish pituitary. In general, the present study provides novel information on time- and dose-related effects of sGnRH and cGnRH-II on GtH subunit and GH mRNA levels and provides a framework for further investigation of GnRH mechanisms of action in the goldfish pituitary.Key words: gonadotropin-releasing hormone, gonadotropin hormone, growth hormone, gene expression, goldfish.

Maturation Stage-Specific Regulation of Megakaryocytic Genes by Pointed-Domain Ets Proteins.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1737-1737
Author(s):  
Liyan Pang ◽  
Xun Wang ◽  
Yuhuan Wang ◽  
Gerd Blobel ◽  
Mortimer Poncz
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Critical Role ◽  
Regulatory Region ◽  
Maturation Stage ◽  
Specific Gene ◽  
Mrna Levels ◽  
Specific Regulation

Abstract The pointed-domain Ets transcription factor Fli-1 has a critical role during megakaryocyte-specific gene expression. Previously, we demonstrated that Fli-1 occupies the early megakaryocyte-specific gene αIIb in vivo. Moreover, our work suggested a mechanism for Fli-1 function by showing that Fli-1 facilitates GATA-1/FOG-1 dependent expression of the αIIb gene. However, studies by others with a targeted disruption of the Fli-1 gene in mice showed that while Fli-1 is essential for normal megakaryocyte maturation, αIIb mRNA levels were not significantly reduced in the resulting megakaryocytes, suggesting that a related Ets factor(s) might compensate for the loss of Fli-1. Here we show that the widely expressed pointed domain Ets protein GABPα specifically binds in vitro to Ets elements from two early megakaryocyte-specific genes, αIIb and c-mpl. Chromatin immunoprecipitation (ChIP) experiments using primary murine fetal liver-derived megakaryocytes reveal that GABPα associates with αIIb and c-mpl in vivo. Moreover, GABPα is capable of mediating GATA-1/FOG-1 synergy in the context of αIIb promoter constructs. These results suggest that GABPα contributes to megakaryocyte-restricted gene expression and is capable of at least partially compensating for the loss of Fli-1. However, loss of Fli-1 leads to a pronounced decrease in the expression of the late megakaryocyte-specific gene GPIX, indicating that compensation by GABPα is incomplete. Consistent with this observation, ChIP experiments fail to detect significant levels of GABPα at the regulatory region of GPIX while Fli-1 is readily detected there. Together, these results point to a model in which Fli-1 and GABPα serve overlapping, but distinct roles, during the development of megakaryocytes. GABPα may be important during early megakaryopoiesis, but Fli-1 exerting an essential role during late stages of maturation.

Tissue-specific gene expression of prolactin receptor in the acute-phase response induced by lipopolysaccharides

2004 ◽  
Vol 287 (4) ◽  
pp. E750-E757 ◽  
Author(s):  
Ana M. Corbacho ◽  
Giuseppe Valacchi ◽  
Lukas Kubala ◽  
Estibaliz Olano-Martín ◽  
Bettina C. Schock ◽  
...  
Keyword(s):  
Acute Phase ◽  
Acute Phase Response ◽  
Prolactin Receptor ◽  
Phase Response ◽  
Specific Gene ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Specific Regulation

Acute inflammation can elicit a defense reaction known as the acute-phase response (APR) that is crucial for reestablishing homeostasis in the host. The role for prolactin (PRL) as an immunomodulatory factor maintaining homeostasis under conditions of stress has been proposed; however, its function during the APR remains unclear. Previously, it was shown that proinflammatory cytokines characteristic of the APR (TNF-α, IL-1β, and IFNγ) induced the expression of the PRL receptor (PRLR) by pulmonary fibroblasts in vitro. Here, we investigated the in vivo expression of PRLR during lipopolysaccharide (LPS)-induced APR in various tissues of the mouse. We show that PRLR mRNA and protein levels were downregulated in hepatic tissues after intraperitoneal LPS injection. Downregulation of PRLR in the liver was confirmed by immunohistochemistry. A suppressive effect on mRNA expression was also observed in prostate, seminal vesicle, kidney, heart, and lung tissues. However, PRLR mRNA levels were increased in the thymus, and no changes were observed in the spleen. The proportion of transcripts for the different receptor isoforms (long, S1, S2, and S3) in liver and thymus was not altered by LPS injection. These findings suggest a complex tissue-specific regulation of PRLR expression in the context of the APR.

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