scholarly journals Entrainment of circadian rhythms depends on firing rates and neuropeptide release of VIP SCN neurons

2018 ◽  
Author(s):  
Cristina Mazuski ◽  
John H. Abel ◽  
Samantha P. Chen ◽  
Tracey O. Hermanstyne ◽  
Jeff R. Jones ◽  
...  
Keyword(s):  
Gene Expression ◽  
Circadian Rhythms ◽  
Time Of Day ◽  
Neuronal Firing ◽  
List Type ◽  
Dependent Manner ◽  
Firing Activity ◽  
Firing Patterns

SummaryThe mammalian suprachiasmatic nucleus (SCN) functions as a master circadian pacemaker, integrating environmental input to align physiological and behavioral rhythms to local time cues. Approximately 10% of SCN neurons express vasoactive intestinal polypeptide (VIP); however, it is unknown how firing activity of VIP neurons releases VIP to entrain circadian rhythms. To identify physiologically relevant firing patterns, we optically tagged VIP neurons and characterized spontaneous firing over three days. VIP neurons had circadian rhythms in firing rate and exhibited two classes of instantaneous firing activity. We next tested whether physiologically relevant firing affected circadian rhythms through VIP release. We found that VIP neuron stimulation with high, but not low, frequencies shifted gene expression rhythms in vitro through VIP signaling. In vivo, high frequency VIP neuron activation rapidly entrained circadian locomotor rhythms. Thus, increases in VIP neuronal firing frequency release VIP and entrain molecular and behavioral circadian rhythms.HighlightsMazuski et al. identified three classes of circadian SCN neurons based on their distinct firing patterns consistent over multiple daysThere are two distinct classes (tonic and irregular firing) of VIP SCN neurons.Stimulation of VIP SCN neurons at physiologically relevant frequencies phase shifts whole-SCN circadian rhythms in gene expression through VIP release. These effects are blocked with VIP antagonists.Firing of VIP SCN neurons entrains circadian rhythms in locomotor behavior in a frequency and time-of-day dependent manner.

scholarly journals Modulatory Effects of Osthole on Lipopolysaccharides-Induced Inflammation in Caco-2 Cell Monolayer and Co-Cultures with THP-1 and THP-1-Derived Macrophages

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Natalia K. Kordulewska ◽  
Justyna Topa ◽  
Małgorzata Tańska ◽  
Anna Cieślińska ◽  
Ewa Fiedorowicz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inflammatory Reaction ◽  
Wide Spectrum ◽  
Cell Monolayer ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.

Comparison of gene expression and activation of transcription factors in organoid-derived monolayer intestinal epithelial cells and organoids

2021 ◽  
Author(s):  
Yu Takahashi ◽  
Yu Inoue ◽  
Keitaro Kuze ◽  
Shintaro Sato ◽  
Makoto Shimizu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Gene Expression Regulation ◽  
Intestinal Epithelial Cells ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Dependent Manner ◽  
Intestinal Epithelial

Abstract Intestinal organoids better represent in vivo intestinal properties than conventionally used established cell lines in vitro. However, they are maintained in three-dimensional culture conditions that may be accompanied by handling complexities. We characterized the properties of human organoid-derived two-dimensionally cultured intestinal epithelial cells (IECs) compared with those of their parental organoids. We found that the expression of several intestinal markers and functional genes were indistinguishable between monolayer IECs and organoids. We further confirmed that their specific ligands equally activate intestinal ligand-activated transcriptional regulators in a dose-dependent manner. The results suggest that culture conditions do not significantly influence the fundamental properties of monolayer IECs originating from organoids, at least from the perspective of gene expression regulation. This will enable their use as novel biological tools to investigate the physiological functions of the human intestine.

Effect of Auraptene on angiogenesis in Xenograft model of breast cancer

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammad Reza Shiran ◽  
Elham Mahmoudian ◽  
Abolghasem Ajami ◽  
Seyed Mostafa Hosseini ◽  
Ayjamal Khojasteh ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Animal Model ◽  
Protein Expression ◽  
Western Blot ◽  
Xenograft Model ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Abstract Objectives Angiogenesis is the most important challenge in breast cancer treatment. Recently, scientists become interesting in rare natural products and intensive researches was performed to identify their pharmacological profile. Auraptene shows helpful effects such as cancer chemo-preventive, anti-inflammatory, anti-oxidant, immuno-modulatory. In this regard, we investigated the anti-angiogenesis effect of Auraptene in in-vitro and in-vivo model of breast cancer. Methods In this study, 4T, MDA-MB-231 and HUVEC cell lines were used. The proliferation study was done by MTT assay. For tube formation assay, 250 matrigel, 1 × 104 HUVEC treated with Auraptene, 20 ng/mL EGF, 20 ng/mL bFGF and 20 ng/mL VEGF were used. Gene expression of important gene related to angiogenesis in animal model of breast cancer was investigated by Real-time PCR. Protein expression of VCAM-1 and TNFR-1 gene related to angiogenesis in animal model of breast cancer was investigated by western-blot. Results Auraptene treatment led to reduction in cell viability of MDA-MB-231 in a concentration-dependent manner. Also, we observed change in the number of tubes or branches formed by cells incubated with 40 and 80 μM Auraptene. Auraptene effect the gene expression of important gene related to angiogenesis (VEGF, VEGFR2, COX2, IFNɣ). Moreover, the western blot data exhibited that Auraptene effect the protein expression of VCAM-1 and TNFR-1. Conclusions Overall, this study shows that Auraptene significantly suppressed angiogenesis via down-regulation of VEGF, VEGFR2, VCAM-1, TNFR-1, COX-2 and up-regulation of IFNγ.

scholarly journals Deletion of the Mycobacterium tuberculosis Resuscitation-Promoting Factor Rv1009 Gene Results in Delayed Reactivation from Chronic Tuberculosis

2006 ◽  
Vol 74 (5) ◽  
pp. 2985-2995 ◽  
Author(s):  
JoAnn M. Tufariello ◽  
Kaixia Mi ◽  
Jiayong Xu ◽  
Yukari C. Manabe ◽  
Anup K. Kesavan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Human Population ◽  
Acute Infection ◽  
Dependent Manner ◽  
Survival Times ◽  
Chronic Infections ◽  
Synthase Inhibitor

ABSTRACT Approximately one-third of the human population is latently infected with Mycobacterium tuberculosis, comprising a critical reservoir for disease reactivation. Despite the importance of latency in maintaining M. tuberculosis in the human population, little is known about the mycobacterial factors that regulate persistence and reactivation. Previous in vitro studies have implicated a family of five related M. tuberculosis proteins, called resuscitation promoting factors (Rpfs), in regulating mycobacterial growth. We studied the in vivo role of M. tuberculosis rpf genes in an established mouse model of M. tuberculosis persistence and reactivation. After an aerosol infection with the M. tuberculosis Erdman wild type (Erdman) or single-deletion rpf mutants to establish chronic infections in mice, reactivation was induced by administration of the nitric oxide (NO) synthase inhibitor aminoguanidine. Of the five rpf deletion mutants tested, one (ΔRv1009) exhibited a delayed reactivation phenotype, manifested by delayed postreactivation growth kinetics and prolonged median survival times among infected animals. Immunophenotypic analysis suggested differences in pulmonary B-cell responses between Erdman- and ΔRv1009-infected mice at advanced stages of reactivation. Analysis of rpf gene expression in the lungs of Erdman-infected mice revealed that relative expression of four of the five rpf-like genes was diminished at late times following reactivation, when bacterial numbers had increased substantially, suggesting that rpf gene expression may be regulated in a growth phase-dependent manner. To our knowledge, ΔRv1009 is the first M. tuberculosis mutant to have a specific defect in reactivation without accompanying growth defects in vitro or during acute infection in vivo.

scholarly journals Nrg1 Is a Transcriptional Repressor for Glucose Repression of STA1 Gene Expression inSaccharomyces cerevisiae

1999 ◽  
Vol 19 (3) ◽  
pp. 2044-2050 ◽  
Author(s):  
Seok Hee Park ◽  
Sang Seok Koh ◽  
Jae Hwan Chun ◽  
Hye Jin Hwang ◽  
Hyen Sam Kang
Keyword(s):  
Gene Expression ◽  
Zinc Finger Protein ◽  
Glucose Repression ◽  
Transcriptional Repressor ◽  
Dependent Manner ◽  
Expression Of Genes ◽  
Dnase I Footprinting ◽  
Genes Encoding

ABSTRACT Expression of genes encoding starch-degrading enzymes is regulated by glucose repression in the yeast Saccharomyces cerevisiae. We have identified a transcriptional repressor, Nrg1, in a genetic screen designed to reveal negative factors involved in the expression of STA1, which encodes a glucoamylase. TheNRG1 gene encodes a 25-kDa C2H2zinc finger protein which specifically binds to two regions in the upstream activation sequence of the STA1 gene, as judged by gel retardation and DNase I footprinting analyses. Disruption of theNRG1 gene causes a fivefold increase in the level of theSTA1 transcript in the presence of glucose. The expression of NRG1 itself is inhibited in the absence of glucose. DNA-bound LexA-Nrg1 represses transcription of a target gene 10.7-fold in a glucose-dependent manner, and this repression is abolished in bothssn6 and tup1 mutants. Two-hybrid and glutathione S-transferase pull-down experiments show an interaction of Nrg1 with Ssn6 both in vivo and in vitro. These findings indicate that Nrg1 acts as a DNA-binding repressor and mediates glucose repression of the STA1 gene expression by recruiting the Ssn6-Tup1 complex.

scholarly journals tRNA-Derived Fragments Target the Ribosome and Function as Regulatory Non-Coding RNA inHaloferax volcanii

Archaea ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Jennifer Gebetsberger ◽  
Marek Zywicki ◽  
Andrea Künzi ◽  
Norbert Polacek
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Ribosomal Subunit ◽  
Fine Tuning ◽  
Transferase Activity ◽  
Dependent Manner ◽  
Efficient Manner ◽  
Stress Dependent

Nonprotein coding RNA (ncRNA) molecules have been recognized recently as major contributors to regulatory networks in controlling gene expression in a highly efficient manner. These RNAs either originate from their individual transcription units or are processing products from longer precursor RNAs. For example, tRNA-derived fragments (tRFs) have been identified in all domains of life and represent a growing, yet functionally poorly understood, class of ncRNA candidates. Here we present evidence that tRFs from the halophilic archaeonHaloferax volcaniidirectly bind to ribosomes. In the presented genomic screen of the ribosome-associated RNome, a 26-residue-long fragment originating from the 5′ part of valine tRNA was by far the most abundant tRF. The Val-tRF is processed in a stress-dependent manner and was found to primarily target the small ribosomal subunitin vitroandin vivo. As a consequence of ribosome binding, Val-tRF reduces protein synthesis by interfering with peptidyl transferase activity. Therefore this tRF functions as ribosome-bound small ncRNA capable of regulating gene expression inH. volcaniiunder environmental stress conditions probably by fine tuning the rate of protein production.

HIF-2α regulates murine hematopoietic development in an erythropoietin-dependent manner

Blood ◽  
2005 ◽  
Vol 105 (8) ◽  
pp. 3133-3140 ◽  
Author(s):  
Marzia Scortegagna ◽  
Kan Ding ◽  
Quiyang Zhang ◽  
Yavuz Oktay ◽  
Michael J. Bennett ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hypoxia Inducible Factor ◽  
Regulatory Region ◽  
Dependent Manner ◽  
Wild Type ◽  
Hematopoietic Development ◽  
Erythropoietin Production ◽  
Hypoxia Treatment

AbstractErythropoiesis in the adult mammal depends critically on erythropoietin, an inducible cytokine with pluripotent effects. Erythropoietin gene expression increases under conditions associated with lowered oxygen content such as anemia and hypoxia. HIF-1α, the founding member of the hypoxia-inducible factor (HIF) alpha class, was identified by its ability to bind and activate the hypoxia-responsive enhancer in the erythropoietin regulatory region in vitro. The existence of multiple HIF alpha members raises the question of which HIF alpha member or members regulates erythropoietin expression in vivo. We previously reported that mice lacking wild-type HIF-2α, encoded by the EPAS1 gene, exhibit pancytopenia. In this study, we have characterized the etiology of this hematopoietic phenotype. Molecular studies of EPAS1-null kidneys reveal dramatically decreased erythropoietin gene expression. EPAS1-null as well as heterozygous mice have impaired renal erythropoietin induction in response to hypoxia. Treatment of EPAS1-null mice with exogenous erythropoietin reverses the hematopoietic and other defects. We propose that HIF-2α is an essential regulator of murine erythropoietin production. Impairments in HIF signaling, involving either HIF-1α or HIF-2α, may play a prominent role in conditions involving altered hematopoietic or erythropoietin homeostasis.

Putative imprinted gene expression in uniparental bovine embryo models

2008 ◽  
Vol 20 (5) ◽  
pp. 589 ◽  
Author(s):  
Nancy T. D' Cruz ◽  
Katrina J. Wilson ◽  
Melissa A. Cooney ◽  
R. Tayfur Tecirlioglu ◽  
Irina Lagutina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Monoallelic Expression ◽  
Cell Physiology ◽  
Imprinted Genes ◽  
Bovine Embryo ◽  
Dependent Manner ◽  
Abnormal Growth

Altered patterns of gene expression and the imprinted status of genes have a profound effect on cell physiology and can markedly alter embryonic and fetal development. Failure to maintain correct imprinting patterns can lead to abnormal growth and behavioural problems, or to early pregnancy loss. Recently, it has been reported that the Igf2R and Grb10 genes are biallelically expressed in sheep blastocysts, but monoallelically expressed at Day 21 of development. The present study investigated the imprinting status of 17 genes in in vivo, parthenogenetic and androgenetic bovine blastocysts in order to determine the prevalence of this unique phenomenon. Specifically, the putatively imprinted genes Ata3, Impact, L3Mbtl, Magel2, Mkrn3, Peg3, Snrpn, Ube3a and Zac1 were investigated for the first time in bovine in vitro fertilised embryos. Ata3 was the only gene not detected. The results of the present study revealed that all genes, except Xist, failed to display monoallelic expression patterns in bovine embryos and support recent results reported for ovine embryos. Collectively, the data suggest that monoallelic expression may not be required for most imprinted genes during preimplantation development, especially in ruminants. The research also suggests that monoallelic expression of genes may develop in a gene- and time-dependent manner.

scholarly journals Time Course of Microbiologic Outcome and Gene Expression in Candida albicans during and following In Vitro and In Vivo Exposure to Fluconazole

2006 ◽  
Vol 50 (4) ◽  
pp. 1311-1319 ◽  
Author(s):  
A. Lepak ◽  
J. Nett ◽  
L. Lincoln ◽  
K. Marchillo ◽  
D. Andes
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Time Course ◽  
Dependent Manner ◽  
Time Points ◽  
In Vivo Expression ◽  
The Impact ◽  
The Relationship

ABSTRACT Pharmacodynamics (PD) considers the relationship between drug exposure and effect. The two factors that have been used to distinguish the PD behaviors of antimicrobials are the impact of concentration on the extent of organism killing and the duration of persistent microbiologic suppression (postantibiotic effect). The goals of these studies were (i) to examine the relationship between antimicrobial PD and gene expression and (ii) to gain insight into the mechanism of fluconazole effects persisting following exposure. Microarrays were used to estimate the transcriptional response of Candida albicans to a supra-MIC F exposure over time in vitro. Fluconazole at four times the MIC was added to a log-phase C. albicans culture, and cells were collected to determine viable growth and for microarray analyses. We identified differential expression of 18% of all genes for at least one of the time points. More genes were upregulated (n = 1,053 [16%]) than downregulated (174 [3%]). Of genes with known function that were upregulated during exposure, most were related to plasma membrane/cell wall synthesis (18%), stress responses (7%), and metabolism (6%). The categories of downregulated genes during exposure included protein synthesis (15%), DNA synthesis/repair (7%), and transport (7%) genes. The majority of genes identified at the postexposure time points were from the protein (17%) and DNA (7%) synthesis categories. In subsequent studies, three genes (CDR1, CDR2, and ERG11) were examined in greater detail (more concentration and time points) following fluconazole exposure in vitro and in vivo. Expression levels from the in vitro and in vivo studies were congruent. CDR1 and CDR2 transcripts were reduced during in vitro fluconazole exposure and during supra-MIC exposure in vivo. However, in the postexposure period, the mRNA abundance of both pumps increased. ERG11 expression increased during exposure and fell in the postexposure period. The expression of the three genes responded in a dose-dependent manner. In sum, the microarray data obtained during and following fluconazole exposure identified genes both known and unknown to be affected by this drug class. The expanded in vitro and in vivo expression data set underscores the importance of considering the time course of exposure in pharmacogenomic investigations.

Abstract 489: The Role of Hemodynamics in Modulating p120 and Kaiso Expression and Activity in Atherogenesis

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Devin L Weinberg ◽  
Andrew W Pryor ◽  
Christin A Hamilton ◽  
Brett R Blackman
Keyword(s):  
Gene Expression ◽  
Inflammatory Marker ◽  
Adherens Junction ◽  
Nuclear Accumulation ◽  
Dependent Manner ◽  
P120 Catenin ◽  
Hemodynamic Forces ◽  
Hemodynamic Regulation

Introduction. The generation of atherosclerosis has been shown to be a non-random process, with endothelial cells (ECs) in regions of disturbed hemodynamics developing an atheroprone (pro-inflammatory) phenotype. While a great deal of research has focused on hemodynamic regulation of EC phenotype, the mechanisms that mediate ECs’ response to local shear stress environment remain elusive. p120-catenin (p120) and its transcription factor binding partner Kaiso are expressed in ECs and possess a variety of functions that potentially contribute to the hemodynamic regulation of EC phenotype in atherosclerosis. Specifically, p120 has been shown to regulate adherens junction stability and regulate gene transcription through interaction with Kaiso. Hypothesis. We hypothesize hemodynamic forces modulate the activity of p120 and Kaiso in a manner that alters local endothelial susceptibility to atherogenesis. Methods. Atheroprone/protective hemodynamic profiles obtained by human carotid artery imaging were applied to human ECs in vitro . Protein/gene expression was then analyzed by Western blot, RT-PCR, and imaging. To determine Kaiso-dependent regulation of target gene expression, siRNAs were used to knockdown Kaiso expression. For in vivo validation, vasculature from Apolipoprotein E -/- mice was isolated, fixed, and stained. Results. In vitro, atheroprotective flow upregulates p120 expression and increases its junctional continuity and nuclear accumulation. There is a flow-dependent increase in Kaiso expression over time in both flow conditions, but p120/Kaiso interaction is increased under atheroprone flow. Kaiso knockdown under protective flow results in decreased expression of the anti-inflammatory genes eNOS (0.49 fold) and KLF2 (0.68 fold) and increased expression of the inflammatory marker VCAM (1.44 fold), suggesting a previously unknown anti-atherogenic function of Kaiso. In preliminary mouse studies, Kaiso is expressed in ECs overlying both healthy and diseased regions, as well as being highly expressed within the lesions. Conclusions. p120 and Kaiso expression are regulated in a flow-dependent manner and are potentially a mechanism by which hemodynamics modulate susceptibility to atherogenesis.

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