Search results for "silencing"

Cockayne syndrome: varied requirement of transcription-coupled nucleotide excision repair for the removal of three structurally different adducts fro…

2014

Hereditary defects in the transcription-coupled nucleotide excision repair (TC-NER) pathway of damaged DNA cause severe neurodegenerative disease Cockayne syndrome (CS), however the origin and chemical nature of the underlying DNA damage had remained unknown. To find out, to which degree the structural properties of DNA lesions determine the extent of transcription arrest in human CS cells, we performed quantitative host cell reactivation analyses of expression vectors containing various synthetic adducts. We found that a single 3-(deoxyguanosin-N 2-yl)-2-acetylaminofluorene adduct (dG(N 2)-AAF) constitutes an unsurmountable obstacle to transcription in both CS-A and CS-B cells and is remov…

Assembly of Polycomb complexes and silencing mechanisms

2003

Polycomb complexes assemble at their target sites and silence neighboring genes when these are not actively transcribed. The action of these complexes and of Trithorax complexes bound to the Polycomb Response Element establish alternative silent or derepressed states that are remembered through cell division and maintained for the rest of development. Recent results that may help explain the properties of these states are reviewed.

Dissecting Abdominal Aortic Aneurysm Is Aggravated by Genetic Inactivation of LIGHT (TNFSF14)

2021

Abdominal aortic aneurysm (AAA), is a complex disorder characterized by vascular vessel wall remodeling. LIGHT (TNFSF14) is a proinflammatory cytokine associated with vascular disease. In the present study, the impact of genetic inactivation of Light was investigated in dissecting AAA induced by angiotensin II (AngII) in the Apolipoprotein E-deficient (Apoe−/−) mice. Studies in aortic human (ah) vascular smooth muscle cells (VSMC) to study potential translation to human pathology were also performed. AngII-treated Apoe−/−Light−/− mice displayed increased abdominal aorta maximum diameter and AAA severity compared with Apoe−/− mice. Notably, reduced smooth muscle α-actin+ area and Acta2 and C…

Inclisiran: a small interfering RNA strategy targeting PCSK9 to treat hypercholesterolemia

2022

Introduction: Inclisiran is a novel posttranscriptional gene silencing therapy that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) synthesis by RNA interference and has a potent, dose-dependent, durable effect in lowering LDL-C, and therefore is an effective drug to treat dyslipidemia, reducing the risk for acute cardiovascular (CV) events. It is safe and well-tolerated. Areas covered: This paper aims to review the mechanism of action of inclisiran while evaluating its efficacy and safety in the treatment of dyslipidemia from data of the clinical trials in the ORION program. Expert opinion: Data from the clinical trials in the ORION program demonstrated efficacy and safety o…

Deciphering the rules underlying xenogeneic silencing and counter-silencing of Lsr2-like proteins

2019

ABSTRACTLsr2-like nucleoid-associated proteins play an important role as xenogeneic silencers (XS) of horizontally acquired genomic regions in actinobacteria. In this study, we systematically analyzed the in vivo constraints underlying silencing and counter-silencing of the Lsr2-like protein CgpS inCorynebacterium glutamicum. Genome-wide analysis revealed binding of CgpS to regions featuring a distinct drop in GC-profile close to the transcription start site (TSS), but also identified an overrepresented motif with multiple A/T steps at the nucleation site of the nucleoprotein complex. Binding of specific transcription factors (TFs) may oppose XS activity leading to counter-silencing. Follow…

Novel molluskan biomineralization proteins retrieved from proteomics: a case study with upsalin.

2012

12 pages; International audience; The formation of the molluskan shell is regulated by an array of extracellular proteins secreted by the calcifying epithelial cells of the mantle. These proteins remain occluded within the recently formed biominerals. To date, many shell proteins have been retrieved, but only a few of them, such as nacreins, have clearly identified functions. In this particular case, by combining molecular biology and biochemical approaches, we performed the molecular characterization of a novel protein that we named Upsalin, associated with the nacreous shell of the freshwater mussel Unio pictorum. The full sequence of the upsalin transcript was obtained by RT-PCR and 5'/3…

DNA-methylation dependent regulation of embryo-specific 5S ribosomal DNA cluster transcription in adult tissues of sea urchin Paracentrotus lividus

2013

Abstract We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus and recently, demonstrated the presence of high heterogeneity in functional 5S rRNA. In this paper, we show some important distinctive data on 5S rRNA transcription for this organism. Using single strand conformation polymorphism (SSCP) analysis, we demonstrate the existence of two classes of 5S rRNA, one which is embryo-specific and encoded by the smallest (700 bp) cluster and the other which is expressed at every stage and encoded by longer clusters (900 and 950 bp). We also demonstrate that the embryo-specific class of 5S rRNA is ex…

The cyclopentenone-type prostaglandin 15-deoxy-delta12,14-prostaglandin J2 inhibits CD95 ligand gene expression in T lymphocytes: interference with p…

2003

Abstract 15-Deoxy-Δ12,14-PGJ2 (15d-PGJ2) is a cyclopentenone-type PG endowed with anti-inflammatory properties and produced by different cells, including those of the immune system. 15d-PGJ2 is a natural ligand of the peroxisome proliferator-activated receptor (PPAR)-γ nuclear receptor, but relevant PPARγ-independent actions mediated by this prostanoid have been described. Fas (APO-1/CD95) and its ligand (Fas-L) are cell surface proteins whose interaction activates apoptosis of Fas-expressing targets. In T cells, the Fas-Fas-L system regulates activation-induced cell death and has been implicated in diseases in which lymphocyte homeostasis is compromised. Moreover, several studies have desc…

GENE SILENCING OF NICOTINAMIDE N-METHYLTRANSFERASE IN ORAL CANCER CELL LINES: EFFECTS ON TUMOR CELL PROLIFERATION

2010

Anti-Inflammatory Action of Heterogeneous Nuclear Ribonucleoprotein A2/B1 in Patients with Autoimmune Endocrine Disorders

2019

Our previous studies documented that human fibroblast-limbal stem cells (f-LSCs) possess immunosuppressive capabilities, playing a role in regulating T-cell activity. This study highlights the molecular activities by which human f-LSCs can attenuate the inflammatory responses of self-reactive peripheral blood mononuclear cells (PBMCs) collected from patients with autoimmune endocrine diseases (AEDs). Anti-CD3 activated PBMCs from twenty healthy donors and fifty-two patients with AEDs were cocultured on f-LSC monolayer. 2D-DIGE proteomic experiments, mass spectrometry sequencing and functional in vitro assays were assessed in cocultured PBMCs. We identified the downmodulation of several huma…