Search results for "CHROMATIN"

Histone acetylation deficits in lymphoblastoid cell lines from patients with Rubinstein-Taybi syndrome.

2012

Background: Rubinstein-Taybi syndrome (RSTS) is a congenital neurodevelopmental disorder defined by postnatal growth deficiency, characteristic skeletal abnormalities and mental retardation and caused by mutations in the genes encoding for the transcriptional co-activators with intrinsic lysine acetyltransferase (KAT) activity CBP and p300. Previous studies have shown that neuronal histone acetylation is reduced in mouse models of RSTS. Methods: The authors identified different mutations at the CREBBP locus and generated lymphoblastoid cell lines derived from nine patients with RSTS carrying distinct CREBBP mutations that illustrate different grades of the clinical severity in the spectrum …

Translocations Disrupting PHF21A in the Potocki-Shaffer-Syndrome Region Are Associated with Intellectual Disability and Craniofacial Anomalies

2012

Contains fulltext : 110038.pdf (Publisher’s version ) (Closed access) Potocki-Shaffer syndrome (PSS) is a contiguous gene disorder due to the interstitial deletion of band p11.2 of chromosome 11 and is characterized by multiple exostoses, parietal foramina, intellectual disability (ID), and craniofacial anomalies (CFAs). Despite the identification of individual genes responsible for multiple exostoses and parietal foramina in PSS, the identity of the gene(s) associated with the ID and CFA phenotypes has remained elusive. Through characterization of independent subjects with balanced translocations and supportive comparative deletion mapping of PSS subjects, we have uncovered evidence that t…

Extent and patterns of MGMT promoter methylation in glioblastoma- and respective glioblastoma-derived spheres.

2010

Abstract Purpose: Quantitative methylation-specific tests suggest that not all cells in a glioblastoma with detectable promoter methylation of the O6-methylguanine DNA methyltransferase (MGMT) gene carry a methylated MGMT allele. This observation may indicate cell subpopulations with distinct MGMT status, raising the question of the clinically relevant cutoff of MGMT methylation therapy. Epigenetic silencing of the MGMT gene by promoter methylation blunts repair of O6-methyl guanine and has been shown to be a predictive factor for benefit from alkylating agent therapy in glioblastoma. Experimental Design: Ten paired samples of glioblastoma and respective glioblastoma-derived spheres (GS), c…

Updating semen analysis: a subpopulation approach

2019

Value of the sperm deoxyribonucleic acid fragmentation level, as measured by the sperm chromatin dispersion test, in the outcome of in vitro fertiliz…

2005

To determine the prognostic value of sperm DNA fragmentation levels, as measured by the sperm chromatin dispersion (SCD) test, in predicting IVF and ICSI outcome.Double-blind prospective study.University-affiliated private IVF setting.A total of 85 couples undergoing infertility treatment with IVF/ICSI.Analysis of DNA fragmentation by the SCD test in 170 aliquots obtained from the ejaculate and from the processed semen used for assisted reproductive technologies (ART).Percentage of spermatozoa with fragmented DNA was statistically correlated with embryo quality and reproductive success.Fertilization rate was inversely correlated with DNA fragmentation (r = -0.245 P = .045). Higher DNA fragm…

Repetition suppression versus enhancement — it's quantity that matters

2013

Upon repetition, certain stimuli induce reduced neural responses (i.e., repetition suppression), whereas others evoke stronger signals (i.e., repetition enhancement). It has been hypothesized that stimulus properties (e.g., visibility) determine the direction of the repetition effect. Here, we show that the very same stimuli can induce both repetition suppression and enhancement, whereby the only determining factor is the number of repetitions. Repeating the same, initially novel low-visible pictures of scenes for up to 5 times enhanced the blood oxygen level-dependent (BOLD) response in scene-selective areas, that is, the parahippocampal place area (PPA) and the transverse occipital sulcus…

Centenarians as a model to discover genetic and epigenetic signatures of healthy ageing.

2018

Abstract Centenarians are a model of successful ageing. The data favours the theory that, in order to live to 100, it is mandatory to inherit the right genetic variants from parents or acquire epigenetic variants through the environment. Therefore, the study of epigenetic signatures of healthy ageing is becoming an important aspect to identify the role of chromatin modification in ageing and understand how manage this fine-tuning system. So, according to the concept of developmental plasticity, establishment of a longevity phenotype requires a combination of stochastic and non-stochastic events that modulate the genetic substrate and leads to a different outcome. It can be concluded that ce…

Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion

2011

Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expressio…

P–074 Chromatin Maturity Index (CMI) in unfixed and live spermatozoa and Aniline Blue (AB) stained as an additional evaluation parameter in idiopathi…

2021

Abstract Study question To investigate whether idiopathic male infertility may be due to the presence of histones in motile spermatozoa using a modified AB staining protocol. Summary answer No correlation between CMI in live motile spermatozoa, DNA Fragmentation Index (DFI) and other conventional seminal parameters were found in male infertile patients. What is known already The AB stain discriminates between lysine-rich histones and arginine/cysteine-rich protamines. Transition from histones to protamines during spermatogenesis remodels chromatin packaging and abnormalities in the substitution of those proteins maybe interfere with seminal parameters and affect male infertility. The correl…

Glycogen synthase 2 is a novel target gene of peroxisome proliferator-activated receptors.

2007

International audience; Glycogen synthase 2 (Gys-2) is the ratelimiting enzyme in the storage of glycogen in liver and adipose tissue, yet little is known about regulation of Gys-2 transcription. The peroxisome proliferator-activated receptors (PPARs) are transcription factors involved in the regulation of lipid and glucose metabolism and might be hypothesized to govern glycogen synthesis as well. Here, we show that Gys-2 is a direct target gene of PPARalpha, PPARbeta/delta and PPARgamma. Expression of Gys-2 is significantly reduced in adipose tissue of PPARalpha-/-, PPARbeta/delta-/- and PPARgamma+/- mice. Furthermore, synthetic PPARbeta/delta, and gamma agonists markedly up-regulate Gys-2…