Transcription Of Specific Genes Research Articles

Prostate cancer: unmet clinical needs and RAD9 as a candidate biomarker for patient management.

Prostate cancer is a complex disease, with multiple subtypes and clinical presentations. Much progress has been made in recent years to understand the underlying genetic basis that drives prostate cancer. Such mechanistic information is useful for development of novel therapeutic targets, to identify biomarkers for early detection or to distinguish between aggressive and indolent disease, and to predict treatment outcome. Multiple tests have become available in recent years to address these clinical needs for prostate cancer. We describe several of these assays, summarizing test details, performance characteristics, and acknowledging their limitations. There is a pressing unmet need for novel biomarkers that can demonstrate improvement in these areas. We introduce one such candidate biomarker, RAD9, describe its functions in the DNA damage response, and detail why it can potentially fill this void. RAD9 has multiple roles in prostate carcinogenesis, making it potentially useful as a clinical tool for men with prostate cancer. RAD9 was originally identified as a radioresistance gene, and subsequent investigations revealed several key functions in the response of cells to DNA damage, including involvement in cell cycle checkpoint control, at least five DNA repair pathways, and apoptosis. Further studies indicated aberrant overexpression in approximately 45% of prostate tumors, with a strong correlation between RAD9 abundance and cancer stage. A causal relationship between RAD9 and prostate cancer was first demonstrated using a mouse model, where tumorigenicity of human prostate cancer cells after subcutaneous injection into nude mice was diminished when RNA interference was used to reduce the normally high levels of the protein. In addition to activity needed for the initial development of tumors, cell culture studies indicated roles for RAD9 in promoting prostate cancer progression by controlling cell migration and invasion through regulation of ITGB1 protein levels, and anoikis resistance by modulating AKT activation. Furthermore, RAD9 enhances the resistance of human prostate cancer cells to radiation in part by regulating ITGB1 protein abundance. RAD9 binds androgen receptor and inhibits androgen-induced androgen receptor's activity as a transcription factor. Moreover, RAD9 also acts as a gene-specific transcription factor, through binding p53 consensus sequences at target gene promoters, and this likely contributes to its oncogenic activity. Given these diverse and extensive activities, RAD9 plays important roles in the initiation and progression of prostate cancer and can potentially serve as a valuable biomarker useful in the management of patients with this disease.

Vitamin K and Bone Metabolism: A Review of the Latest Evidence in Preclinical Studies.

Bone is a metabolically active tissue that renews itself throughout one's life. Cytokines along with several hormonal, nutritional, and growth factors are involved in tightly regulated bone remodeling. Accordingly, vitamin K as a multifunctional vitamin has been recently deemed appreciable as a topic of research as it plays a pivotal role in maintenance of the bone strength, and it has been proved to have a positive impact on the bone metabolism. Vitamin K exerts its anabolic effect on the bone turnover in different ways such as promoting osteoblast differentiation, upregulating transcription of specific genes in osteoblasts, and activating the bone-associated vitamin k dependent proteins which play critical roles in extracellular bone matrix mineralization. There is also credible evidence to support the effects of vitamin k2 on differentiation of other mesenchymal stem cells into osteoblast. The main objective of the present paper is to comprehensively outline the preclinical studies on the properties of vitamin K and its effects on the bone metabolism. The evidence could shed light on further clinical studies to improve osteogenesis in bone graft surgeries.

Targeted Deletion of ATF4 in ß Cells Leads to the Vulnerability and Dedifferentiation during ER Stress

ATF4 is the main transcriptional regulator of the Unfolded Protein Response (UPR) that promote restoration of normal ER function, although the contribution of ATF4 on β-cells remains poorly understood. Therefore, we developed mature β-cell specific ATF4 knockout mice (βATF4KO), were crossed with mice expressing Cre recombinase under the control of insulin promoter. ATF4-deleted β-cells were comparable to WT under normal condition but were susceptible to ER stress. To examine the role of ATF4 in vivo, we bred the Akita insulin folding mutation onto βATF4KO background. Akita/βATF4KO were dramatically compromised as shown by overt hyperglycemia in their early age and remarkable short life span due to ketoacidosis. Interestingly, we found that increased number of cells staining for glucagon, somatostatin or pancreatic polypeptide in the islets of Akita/βATF4KO, suggesting the increased β-cell dedifferentiation. We further employed the gain-of-function study using β-cell specific transgenic mice expressing Fv2E-PERK, which can activate PERK/ATF4 signaling upon addition of the artificial ligand. The induced activation of PERK/ATF4 signaling resulted in reduced insulin secretion without any sign of β-cell apoptosis. Microarray analysis revealed that several key β-cell specific transcription genes such as Pdx1 and MafA were inhibited by the activation of PERK/ATF4 signaling. We demonstrated that ATF4-deleted β-cells are more vulnerable to dedifferentiation during ER stress and excess ATF4 has inhibitory effect in β-cell function. Overall, our study has uncovered that the importance of ATF4 in governing β-cell adaptation and resilience during ER stress. Disclosure K. Kitakaze: None. K. Kurahashi: None. M. Miyake: None. Y. Hamada: None. M. Oyadomari: None. S. Oyadomari: None.

Structural Biology of STAT3 and Its Implications for Anticancer Therapies Development.

Transcription factors are proteins able to bind DNA and induce the transcription of specific genes. Consequently, they play a pivotal role in multiple cellular pathways and are frequently over-expressed or dysregulated in cancer. Here, we will focus on a specific “signal transducer and activator of transcription” (STAT3) factor that is involved in several pathologies, including cancer. For long time, the mechanism by which STAT3 exerts its cellular functions has been summarized by a three steps process: (1) Protein phosphorylation by specific kinases, (2) dimerization promoted by phosphorylation, (3) activation of gene expression by the phosphorylated dimer. Consequently, most of the inhibitors reported in literature aimed at blocking phosphorylation and dimerization. However, recent observations reopened the debate and the entire functional mechanism has been revisited stimulating the scientific community to pursue new inhibition strategies. In particular, the dimerization of the unphosphorylated species has been experimentally demonstrated and specific roles proposed also for these dimers. Despite difficulties in the expression and purification of the full length STAT3, structural biology investigations allowed the determination of atomistic structures of STAT3 dimers and several protein domains. Starting from this information, computational methods have been used both to improve the understanding of the STAT3 functional mechanism and to design new inhibitors to be used as anticancer drugs. In this review, we will focus on the contribution of structural biology to understand the roles of STAT3, to design new inhibitors and to suggest new strategies of pharmacological intervention.

Regulatory mechanisms of thiol-based redox sensors: lessons learned from structural studies on prokaryotic redox sensors.

Oxidative stresses, such as reactive oxygen species, reactive electrophilic species, reactive nitrogen species, and reactive chlorine species, can damage cellular components, leading to cellular malfunction and death. In response to oxidative stress, bacteria have evolved redox-responsive sensors that enable them to simultaneously monitor and eradicate potential oxidative stress. Specifically, redox-sensing transcription regulators react to oxidative stress by means of modifying the thiol groups of cysteine residues, functioning as part of an efficient survival mechanism for many bacteria. In general, oxidative molecules can induce changes in the three-dimensional structures of redox sensors, which, in turn, affects the transcription of specific genes in detoxification pathways and defense mechanisms. Moreover, pathogenic bacteria utilize these redox sensors for adaptation and to evade subsequent oxidative attacks from host immune defense. For this reason, the redox sensors of pathogenic bacteria are potential antibiotic targets. Understanding the regulatory mechanisms of thiol-based redox sensors in bacteria will provide insight and knowledge into the discovery of new antibiotics.

Modulating the expression of Chtop, a versatile regulator of gene-specific transcription and mRNA export

ABSTRACTChtop binds competitively to the arginine methyltransferases PRMT1 and PRMT5, thereby promoting the asymmetric or symmetric methylation of arginine residues, respectively. In cooperation with PRMT1, Chtop activates transcription of certain gene groups, such as the estrogen-inducible genes in breast cancer cells, the 5-hydroxymethylcytosine-modified genes involved in glioblastomagenesis, or the Zbp-89-dependent genes in erythroleukemia cells. Chtop also represses expression of the fetal γ-globin gene. In addition, Chtop is a component of the TREX complex that links transcription elongation to mRNA export. The regulation of Chtop expression is, therefore, a key process during the expression of certain gene groups and pathogenesis of certain diseases. Our recent study revealed that cellular levels of Chtop are strictly autoregulated by a mechanism involving intron retention and nonsense-mediated mRNA decay. Here, we summarize roles of Chtop in gene-specific expression and highlight our recent findings concerning the autoregulation of Chtop.

Using Rexinoids to Program Effector T cells for Homing to Mucosal Sites of Virus Transmission

Abstract Vaccines are the most effective defense against infectious diseases. To be most successful, vaccines must target the induced immune response to chief sites of pathogen entry: epithelial and mucosal surfaces. We have previously shown that the biologically active form of Vitamin A, all-trans retinoic acid (ATRA), can directly modulate the expression of gut mucosal-homing receptors on T cells as binding of ATRA to the retinoic acid receptor (RAR), which partners with the retinoid X receptor (RXR), promotes transcription of specific genes. Rexinoids, synthetic ligands for the RXR, have potential to mimic or improve the immune effects of vitamin A by enhancing RAR-mediated transcription. Additionally, rexinoids have a greater potential for clinical use due to their improved solubility and stability, making them candidates to incorporate into vaccines. Here, we explored the possibility of different rexinoids to function as adjuvants during vaccination to program effector T cell expression of the gut-homing receptors CCR9, α4β7, and CD103. CD8 T cells obtained from transgenic mice were co-cultured with peptide and set concentration of each rexinoid, followed by flow cytometric analysis of receptor expression. We observed increased expression of gut-homing receptors during activation in the presence of certain rexinoids, indicating that they can mimic the effects of ATRA. Furthermore, we saw a cooperative relationship between other rexinoids and ATRA, as co-culturing with sub-optimal doses of each resulted in enhanced expression. Our findings lend support for the prospective use of these rexinoids as adjuvants during vaccination and in therapeutic approaches against diseases transmitted across mucosal surfaces.

Prion protein testis specific (PRNT) gene polymorphisms and transcript level in ovine spermatozoa: Implications in freezability, fertilization and embryo production

An essential role of prion protein testis specific (PRNT) and prion protein 2 dublet (PRND) genes in the male reproductive function has been highlighted, although a deeper knowledge for the mechanisms involved is still lacking. Our goal was to determine the importance of the PRNT haplotypic variants and mRNA expression levels in ovine spermatozoa freezability and ability for fertilization and embryo developmental processes. Their association with the PRND gene polymorphisms was also analyzed. DNA from rams belonging to three Portuguese sheep breeds (n = 28) was screened by single-strand conformation polymorphism (SSCP) analysis to identify the PRNT and PRND polymorphisms. Semen collected from these rams was cryopreserved and fertility traits evaluated. The SSCP analyses revealed polymorphisms in the codons 6, 38, 43 and 48 of the PRNT coding region - respectively c.17C > T (p.Ser6Phe, which disrupts a consensus arginine-X-X serine/threonine motif); c.112G > C (p.Gly38 > Arg); and synonymous c.129T > C and c.144A > G. The polymorphisms in codons 6, 38 and 48 occur simultaneously while the one in codon 43 occurs independently. Six haplotypes were identified in the PRNT coding region, resulting in three different amino acid polymorphic variants (6S-38G-43C-48V, S6F-G38R-43C-48V and 6F-38R-43C-48V). The PRNT gene mRNA transcript level in spermatozoa was related to the identified haplotypic variants, either considering the codons 6-38-48 (P ≤ 0.0001) or the codon 43 alone (P ≤ 0.0001) or altogether (P ≤ 0.0001). An interaction between PRNT haplotypes and PRND genotypes on PRNT transcript level was also identified (P = 0.0003). Rams carrying the 17C-112G-144A PRNT haplotype had sperm with the highest post-thawed individual motility (P ≤ 0.03). Combined PRNT and PRND polymorphic variation influenced the post-thawed individual motility (P = 0.01). The male PRNT haplotypic, either considering the codons 6-38-48 and 43 altogether or the codon 43 alone, interfered (P ≤ 0.04) in embryo production rates. In conclusion, our data confirm that the PRNT gene is highly polymorphic in sheep and that the PRNT and PRND genotypes are associated. The identified polymorphisms of PRNT coding region seems to interfere on the ram spermatozoa mRNA transcript level and on male fertility, specifically in sperm freezability and ability for embryo development.

HDAC genes play distinct and redundant roles in Cryptococcus neoformans virulence

The human fungal pathogen Cryptococcus neoformans undergoes many phenotypic changes to promote its survival in specific ecological niches and inside the host. To explore the role of chromatin remodeling on the expression of virulence-related traits, we identified and deleted seven genes encoding predicted class I/II histone deacetylases (HDACs) in the C. neoformans genome. These studies demonstrated that individual HDACs control non-identical but overlapping cellular processes associated with virulence, including thermotolerance, capsule formation, melanin synthesis, protease activity and cell wall integrity. We also determined the HDAC genes necessary for C. neoformans survival during in vitro macrophage infection and in animal models of cryptococcosis. Our results identified the HDA1 HDAC gene as a central mediator controlling several cellular processes, including mating and virulence. Finally, a global gene expression profile comparing the hda1Δ mutant versus wild-type revealed altered transcription of specific genes associated with the most prominent virulence attributes in this fungal pathogen. This study directly correlates the effects of Class I/II HDAC-mediated chromatin remodeling on the marked phenotypic plasticity and virulence potential of this microorganism. Furthermore, our results provide insights into regulatory mechanisms involved in virulence gene expression that are likely shared with other microbial pathogens.

HSV-1-induced disruption of transcription termination resembles a cellular stress response but selectively increases chromatin accessibility downstream of genes.

Lytic herpes simplex virus 1 (HSV-1) infection triggers disruption of transcription termination (DoTT) of most cellular genes, resulting in extensive intergenic transcription. Similarly, cellular stress responses lead to gene-specific transcription downstream of genes (DoG). In this study, we performed a detailed comparison of DoTT/DoG transcription between HSV-1 infection, salt and heat stress in primary human fibroblasts using 4sU-seq and ATAC-seq. Although DoTT at late times of HSV-1 infection was substantially more prominent than DoG transcription in salt and heat stress, poly(A) read-through due to DoTT/DoG transcription and affected genes were significantly correlated between all three conditions, in particular at earlier times of infection. We speculate that HSV-1 either directly usurps a cellular stress response or disrupts the transcription termination machinery in other ways but with similar consequences. In contrast to previous reports, we found that inhibition of Ca2+ signaling by BAPTA-AM did not specifically inhibit DoG transcription but globally impaired transcription. Most importantly, HSV-1-induced DoTT, but not stress-induced DoG transcription, was accompanied by a strong increase in open chromatin downstream of the affected poly(A) sites. In its extent and kinetics, downstream open chromatin essentially matched the poly(A) read-through transcription. We show that this does not cause but rather requires DoTT as well as high levels of transcription into the genomic regions downstream of genes. This raises intriguing new questions regarding the role of histone repositioning in the wake of RNA Polymerase II passage downstream of impaired poly(A) site recognition.

Transforming Growth Factor β-Induced Proliferative Arrest Mediated by TRIM26-Dependent TAF7 Degradation and Its Antagonism by MYC.

Recognition of gene promoters by RNA polymerase II is mediated by general transcription factor IID (TFIID), which has been thought to be a static complex and to play a passive role in the regulation of gene expression under the instruction of gene-specific transcription factors. Here we show that transforming growth factor β (TGF-β) induced degradation of the TFIID subunit TAF7 in cultured mouse mammary epithelial cells and that this effect was required for proliferative arrest in response to TGF-β stimulation. TGF-β stimulated transcription of the gene for the ubiquitin ligase TRIM26, which was shown to ubiquitylate TAF7 and thereby to target it for proteasomal degradation. Sustained exposure of cells to TGF-β resulted in recovery from proliferative arrest in association with amplification of the Myc proto-oncogene, with MYC inhibiting TRIM26 induction by TGF-β. Our data thus show that TFIID is not simply a general mediator of transcription but contributes to the regulation of transcription in response to cell stimulation, playing a key role in the cytostatic function of TGF-β.

Multifaceted Targeting of the Chromatin Mediates Gonadotropin-Releasing Hormone Effects on Gene Expression in the Gonadotrope.

Gonadotropin-releasing hormone (GnRH) stimulates the expression of multiple genes in the pituitary gonadotropes, most notably to induce synthesis of the gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), but also to ensure the appropriate functioning of these cells at the center of the mammalian reproductive endocrine axis. Aside from the activation of gene-specific transcription factors, GnRH stimulates through its membrane-bound receptor, alterations in the chromatin that facilitate transcription of its target genes. These include changes in the histone and DNA modifications, nucleosome positioning, and chromatin packaging at the regulatory regions of each gene. The requirements for each of these events vary according to the DNA sequence which determines the basal chromatin packaging at the regulatory regions. Despite considerable progress in this field in recent years, we are only beginning to understand some of the complexities involved in the role and regulation of this chromatin structure, including new modifications, extensive cross talk, histone variants, and the actions of distal enhancers and non-coding RNAs. This short review aims to integrate the latest findings on GnRH-induced alterations in the chromatin of its target genes, which indicate multiple and diverse actions. Understanding these processes is illuminating not only in the context of the activation of these hormones during the reproductive life span but may also reveal how aberrant epigenetic regulation of these genes leads to sub-fertility.

Targeting histone deacetylases in endometrial cancer: a paradigm-shifting therapeutic strategy?

Endometrial cancer is increasingly prevalent in western societies and affects mainly postmenopausal women; notably incidence rates have been rising by 1.9% per year on average since 2005. Although the early-stage endometrial cancer can be effectively managed with surgery, more advanced stages of the disease require multimodality treatment with varying results. In recent years, endometrial cancer has been extensively studied at the molecular level in an attempt to develop effective therapies. Recently, a family of compounds that alter epigenetic expression, namely histone deacetylase inhibitors, have shown promise as possible therapeutic agents in endometrial cancer. The present review aims to discuss the therapeutic potential of these agents. This literature review was performed using the MEDLINE database; the search terms histone, deacetylase, inhibitors, endometrial, targeted therapies for endometrial cancer were employed to identify relevant studies. We only reviewed English language publications and also considered studies that were not entirely focused on endometrial cancer. Ultimately, sixty-four articles published until January 2018 were incorporated into our review. Studies in cell cultures have demonstrated that histone deacetylase inhibitors exert their antineoplastic activity by promoting expression of p21WAF1 and p27KIP1, cyclin-dependent kinase inhibitors, that have important roles in cell cycle regulation; importantly, the transcription of specific genes (e.g., E-cadherin, PTEN) that are commonly silenced in endometrial cancer is also enhanced. In addition to these abstracts effects, novel compounds with histone deacetylase inhibitor activity (e.g., scriptaid, trichostatin, entinostat) have also demonstrated significant antineoplastic activity both in vitro and in vivo, by liming tumor growth, inducing apoptosis, inhibiting angiogenesis and potentiating the effects of chemotherapy. The applications of histone deacetylase inhibitors in endometrial cancer appear promising; nonetheless, additional trials are necessary to establish the therapeutic role, clinical utility, and safety of these promising compounds.

Inhibition of p53 prevents diabetic cardiomyopathy by preventing early-stage apoptosis and cell senescence, reduced glycolysis, and impaired angiogenesis

Elevated tumor suppressor p53 expression has been associated with heart diseases, including the diabetic heart. However, its precise role in the pathogenesis of diabetic cardiomyopathy (DCM) remains unclear. We hypothesized that the development of DCM is attributed to up-regulated p53-mediated both early cardiac cell death and persistent cell senescence, glycolytic and angiogenetic dysfunctions. The present study investigated the effect of p53 inhibition with its specific inhibitor pifithrin-α (PFT-α) on the pathogenesis of DCM and its associated mechanisms. Type 1 diabetes was induced with multiple low doses of streptozotocin. Both hyperglycemic and age-matched control mice were treated with and without PFT-α five times a week for 2 months and then sacrificed at 3 and 6 months post-diabetes. Treatment with PFT-α significantly prevented the progression of diabetes-induced cardiac remodeling and dysfunction (i.e., DCM). Mechanistically, the inhibition of p53 prevented the cardiac apoptosis during early-stage diabetes (0.5 month), attenuated diabetes-induced cell senescence (3 and 6 months), and improved both glycolytic and angiogenic defects by increasing hypoxia-induced factor (HIF)-1α protein stability and upregulating HIF-1α transcription of specific target genes at 3 and 6 months after diabetes. Therefore, the targeted inhibition of p53 in diabetic individuals may provide a novel approach for the prevention of DCM.

The ancient role for GATA2/3 transcription factor homolog in the hemocyte production of oyster

Hemocytes, the cellular component of invertebrate hemolymph, are essential for invertebrate immunity, but the hematopoiesis and regulation mechanism are still largely unknown. In the present study, a conserved hematopoietic transcription factor Cg-GATA2/3 was identified in Pacific oyster Crassotrea gigas, which was evolutionarily close to the vertebrate GATA1/2/3. Cg-GATA2/3 was mainly distributed in the immune organs, such as gill, hemocytes, and mantle. After Cg-GATA2/3 was interferenced by dsRNA, the mRNA expressions of hemocytes specific gene (EcSOD) and hematopoietic transcription factor (C-Myb) were all significant down-regulated, and the hemocyte renewal rates also decreased both in hemolymph and gill. During the larval developmental stages, the mRNA transcripts of Cg-GATA2/3 increased immediately after fertilization and kept a high level during blastula and early trochophore larvae stage (4-10 hpf, hours post fertilization), then decreased sharply in early D-veliger larvae stage (15 hpf). Whole-mount immunofluorescence assay further revealed that the abundant immunoreactivity of Cg-GATA2/3 was distributed in the whole body of blastula and gastrula embryos, while specialized gradually to a ring structure around the dorsal region in trochophore larvae. In the D-veliger and umbo larvae, scattered positive signals appeared in the specific sinus structure on the dorsal side and velum region. These results demonstrated that Cg-GATA2/3 was a hematopoietic lineage-specific transcription factor to regulate the hemocyte production, and it could also be used as hematopoietic specific marker to trace potential developmental events of hematopoiesis during ontogenesis of oyster.

Improvement of synaptic plasticity by pharmacological activation of RXR nuclear receptors is PPARα dependent.

Event Abstract Back to Event Improvement of synaptic plasticity by pharmacological activation of RXR nuclear receptors is PPARα dependent. Nathalie PIERROT1, 2*, Laurence Ris3, Ilie-Cosmin STANCU STANCU4, Karelle Leroy5, Pascal Kienlen-Campard1, Philippe Gailly1, Jean-Pierre Brion5, Ilse Dewachter4* and Jean-Noël Octave1 1 Université Catholique de Louvain, Belgium 2 Institute of Neuroscience, Catholic University of Leuven, Belgium 3 University of Mons, Belgium 4 University of Hasselt, Belgium 5 Free University of Brussels, Belgium Retinoid X receptors (RXRs) are receptors belonging to the nuclear receptor superfamily of ligand-dependent transcription factors, containing different members including the Peroxisome Proliferator-Activated Receptors (PPARs). These receptors regulate the transcription of target genes through their binding with sequence-specific elements located in gene promoters. Activation of PPARs, which form obligatory heterodimers with RXRs, stimulates the transcription of specific target genes encoding proteins involved in numerous biological processes such as reproduction, development, adipogenesis, energy balance, lipid and glucose biosynthesis and inflammation. Interestingly, a potential involvement of RXRs in neuronal activity was recently proposed since activation of RXRs with specific ligands improves behaviour and cognition in various mouse models of neurodegenerative diseases. However, the mechanisms involved are not fully understood. We have analyzed how bexarotene-mediated activation of RXRs nuclear receptors could modulate synaptic plasticity, an activity-dependent change in synaptic strength in the hippocampus considered as a prominent mechanism underlying learning and memory formation in the mammalian brain. By measuring long-term potentiation (LTP) at hippocampal CA3-CA1 synapses, we observed that activation of RXRs improved hippocampal synaptic plasticity in a transgenic mouse model with cognitive deficits by specifically increasing the expression of the GluA1 subunit of the AMPA receptors. This upregulation of GluA1 expression together with improvement of hippocampal synaptic plasticity induced by activation of RXRs were completely abolished in the absence of PPARalpha. These results indicate that improvement of synaptic functions induced by activation of RXRs is PPARalpha dependent. Keywords: Nuclear receptors (LXR, PPAR, RXR), synaptic plasiticty, LTP (Long Term Potentiation), glutamate receptor, Hippocampus Conference: Belgian Brain Congress 2018 — Belgian Brain Council, LIEGE, Belgium, 19 Oct - 19 Oct, 2018. Presentation Type: e-posters Topic: NOVEL STRATEGIES FOR NEUROLOGICAL AND MENTAL DISORDERS: SCIENTIFIC BASIS AND VALUE FOR PATIENT-CENTERED CARE Citation: PIERROT N, Ris L, STANCU I, Leroy K, Kienlen-Campard P, Gailly P, Brion J, Dewachter I and Octave J (2019). Improvement of synaptic plasticity by pharmacological activation of RXR nuclear receptors is PPARα dependent.. Front. Neurosci. Conference Abstract: Belgian Brain Congress 2018 — Belgian Brain Council. doi: 10.3389/conf.fnins.2018.95.00017 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Jul 2018; Published Online: 17 Jan 2019. * Correspondence: PhD. Nathalie PIERROT, Université Catholique de Louvain, Louvain-la-Neuve, Belgium, nathalie.pierrot@uclouvain.be Prof. Ilse Dewachter, University of Hasselt, Hasselt, Limburg, 3500, Belgium, ilse.dewachter@uhasselt.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nathalie PIERROT Laurence Ris Ilie-Cosmin STANCU STANCU Karelle Leroy Pascal Kienlen-Campard Philippe Gailly Jean-Pierre Brion Ilse Dewachter Jean-Noël Octave Google Nathalie PIERROT Laurence Ris Ilie-Cosmin STANCU STANCU Karelle Leroy Pascal Kienlen-Campard Philippe Gailly Jean-Pierre Brion Ilse Dewachter Jean-Noël Octave Google Scholar Nathalie PIERROT Laurence Ris Ilie-Cosmin STANCU STANCU Karelle Leroy Pascal Kienlen-Campard Philippe Gailly Jean-Pierre Brion Ilse Dewachter Jean-Noël Octave PubMed Nathalie PIERROT Laurence Ris Ilie-Cosmin STANCU STANCU Karelle Leroy Pascal Kienlen-Campard Philippe Gailly Jean-Pierre Brion Ilse Dewachter Jean-Noël Octave Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Transcriptome profiling of sorted endoreduplicated nuclei from tomato fruits: how the global shift in expression ascribed to DNA ploidy influences RNA-Seq data normalization and interpretation.

As part of normal development most eukaryotic organisms, ranging from insects and mammals to plants, display variations in nuclear ploidy levels resulting from somatic endopolyploidy. Endoreduplication is the major source of endopolyploidy in higher plants. Endoreduplication is a remarkable characteristic of the fleshy pericarp tissue of developing tomato fruits, where it establishes a highly integrated cellular system that acts as a morphogenetic factor supporting cell growth. However, the functional significance of endoreduplication is not fully understood. Although endoreduplication is thought to increase metabolic activity due to a global increase in transcription, the issue of gene-specific ploidy-regulated transcription remains open. To investigate the influence of endoreduplication on transcription in tomato fruit, we tested the feasibility of a RNA sequencing (RNA-Seq) approach using total nuclear RNA extracted from purified populations of flow cytometry-sorted nuclei based on their DNA content. Here we show that cell-based approaches to the study of RNA-Seq profiles need to take into account the putative global shift in expression between samples for correct analysis and interpretation of the data. From ploidy-specific expression profiles we found that the activity of cells inside the pericarp is related both to the ploidy level and their tissue location.

163 Treatment of Growth Differentiation Factor 8 (GDF8) During Porcine Oocyte In Vitro Maturation Changed Transcriptional Pattern and AKT Signaling

Growth differentiation factor 8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. The purpose of this study was to investigate the effects of GDF8 on porcine oocytes during in vitro maturation (IVM). We investigated specific gene transcription levels in oocytes and cumulus cells (CC) after IVM by realtime PCR array, and specific protein expression and activation levels in matured CC by Western blotting. To collect IVM oocytes, the cumulus–oocyte complexes (COC) were aspirated and matured in 500 μL of M199 containing 10% porcine follicular fluid and eCG and hCG for 22 h, and then cultured in M199 without hormones for 22 h. Each concentration (0, 1, 10, and 100 ng mL−1) of GDF8 was included in M199 during whole process of in vitro maturation. Data were analysed by ANOVA followed by Duncan using SPSS (IBM/SPSS, Armonk, NY, USA). Data are presented as means, and differences were considered significant at P < 0.05. After 44 h of IVM, oocytes were mechanically denuded from CC with 0.1% of hyaluronidase, and then the separated oocytes and CC were sampled following each group. To assess the effect of GDF8 on specific gene transcription level changes as a dose response during IVM, a realtime PCR array was performed. In CC, the 1 and 10 ng mL−1 GDF8 supplement groups showed that transcription levels of transcription co-factors CBP and SP1, cell metabolic regulator MAPK1, and cumulus expansion-related genes Has2, Cox-2, Ptx3, and Areg were significantly different from control when hierarchically clustered by euclidean distance with average linkage method after IVM. In matured oocytes, the 10 and 100 ng mL−1 GDF8 supplement groups showed the maternal factors JMJD3 and Zar1, transcriptional regulator FOXO1, Sirt1, and Sirt2, mitochondrial activity factor Sirt3, ACSL3, and ACADL, anti-apoptosis gene BCL-2, and oocyte secrete factor BMP15 mRNA transcription levels were significantly different compared with control. To determine the effect of GDF8 supplement during IVM, the oocyte maturational regulator AKT protein expression and phosphorylation levels analysed in CC by Western blotting. The 10 and 100 ng mL−1 supplement groups showed significantly increase phosphorylated (P)-AKT per total (T)-AKT (1.22 and 1.18 times higher than control) protein levels (P < 0.05). In conclusion, supplement of GDF8 during IVM activates FOXO homologue transcription and induces cumulus cell expansion via activation of AKT signalling in CC. During the process of IVM, the changes in transcriptional landscape in CC may result in accumulation of maternal factors and mitochondrial activation in oocytes. This work was supported, in part, by a grant from the ‘the Next-Generation BioGreen 21 Program (Project No. PJ011288, PJ011077)’ Rural Development Administration and the ‘National Research Foundation of Korea Grant funded by the Korean Government (NRF-2016R1D1A1B03933191, NRF-2017R1A2B4002546)’, Republic of Korea.

Development of a tissue-specific ribosome profiling approach in Drosophila enables genome-wide evaluation of translational adaptations.

Recent advances in next-generation sequencing approaches have revolutionized our understanding of transcriptional expression in diverse systems. However, measurements of transcription do not necessarily reflect gene translation, the process of ultimate importance in understanding cellular function. To circumvent this limitation, biochemical tagging of ribosome subunits to isolate ribosome-associated mRNA has been developed. However, this approach, called TRAP, lacks quantitative resolution compared to a superior technology, ribosome profiling. Here, we report the development of an optimized ribosome profiling approach in Drosophila. We first demonstrate successful ribosome profiling from a specific tissue, larval muscle, with enhanced resolution compared to conventional TRAP approaches. We next validate the ability of this technology to define genome-wide translational regulation. This technology is leveraged to test the relative contributions of transcriptional and translational mechanisms in the postsynaptic muscle that orchestrate the retrograde control of presynaptic function at the neuromuscular junction. Surprisingly, we find no evidence that significant changes in the transcription or translation of specific genes are necessary to enable retrograde homeostatic signaling, implying that post-translational mechanisms ultimately gate instructive retrograde communication. Finally, we show that a global increase in translation induces adaptive responses in both transcription and translation of protein chaperones and degradation factors to promote cellular proteostasis. Together, this development and validation of tissue-specific ribosome profiling enables sensitive and specific analysis of translation in Drosophila.

Abstract 20953: M1 and M2 Specific Purinergic Receptor Repertoire Alters Response to Damage Associated Molecular Patterns

Introduction: Dying cells release damage associated molecular patterns (DAMPs) like nucleotides into the extracellular fluid, orchestrating a profound immune response. Purinergic receptors decrypt the composition of extracellular nucleotides and translate it to distinct cellular reactions. M1 and M2 macrophages are immune cells involved in many diseases which react in a completely different way. Nevertheless, how the microenvironment exactly triggers their behavior is not fully understood. Hypothesis: We hypothesize a distinct expression pattern of purinergic receptors on M1 and M2 macrophages which leads to an unique microenvironment recognition and behavior. Methods: Macrophages were generated by bone marrow isolation and cultivation with macrophage colony stimulating factor (M-CSF). Bone marrow derived macrophages (BMDMs) were differentiated to M1 via addition of IFNγ and LPS. M2 differentiation was initiated by the addition of IL-4. Gene transcription quantification was assessed by real-time PCR. Intracellular Ca 2+ signaling was quantified by Fluo-4 AM. Results: Differentiation of BMDMs with either IFNγ/LPS or IL-4 leads to the upregulation of M1 or M2 specific gene transcription. Subsequent real-time PCR analysis of purinergic receptors revealed a strong relationship between the expression pattern and the differentiation to M1 or M2 macrophages. Whereas M1 macrophages upregulate predominantly G αi coupled metabotropic P2Y receptors, M2 macrophages preferentially upregulate G αq coupled P2Y receptors. Comparison of the two ADP-dependent P2Y receptors (P2Y 1 and P2Y 13 ) showed a M1 and M2 specific expression pattern with M1 macrophages solely expressing the G αi coupled P2Y 13 and M2 macrophages exclusively expressing the G αq coupled P2Y 1 receptor. In agreement with the specific expression pattern, ADP stimulation evokes a significant Ca 2+ flux in M2 macrophages but failed to induce it in M1 macrophages. Conclusion: Our experiments revealed for the first time that M1 and M2 macrophages express a unique purinergic receptor repertoire and sense the nucleotide based microenvironment differently. With this knowledge we could interfere with one macorphage subtype without disturbing the others.