Search results for "telomere"
showing 10 items of 153 documents
Telomere length in leukocytes and cervical smears of women with high-risk human papillomavirus (HR HPV) infection
2019
Objective: Persistent high-risk HPV (HR HPV) infection leads to the development of squamous intraepithelial lesions, which in turn may progress to cervical cancer. Telomere elongation or shortening may indicate a carcinogenesis process. In the present study, we analyzed telomere length from blood and cervical smears of women without and with high-risk HPV infection. Materials and methods: Telomere length was quantified by real-time PCR in blood and cervical smears from 48 women with high-risk HPV infection and HGSIL or LGSIL, 29 women HR-HPV positive without SIL, and 11 HPV-negative women. Results: No correlation was found between age and telomere length in blood and cervical smears. Women …
Possible Association of Telomere Length with Sleep Duration. A Preliminary Pilot study in a Sicilian Cohort with Centenarians
2021
Telomere length (TL) is considered a biomarker of ageing although this topic is still debated. Also, sleep pattern changes are physiological part of the normal ageing process. In fact, it is widely recognized that sleep duration declines with age, leading to dysregulation of circadian rhythms. The aim of our study was to analyse the possible association of sleep duration with TL in a sample of 135 subjects with ages ranging from 20 to 111 years, recruited from Palermo and neighbouring municipalities in Sicily (Italy). Preliminary data suggest that relative TL (RTL) decreases with age in both men and women. However, at older ages, the difference between men and women tends to narrow. Nonagen…
Biological clocks and physical functioning in monozygotic female twins
2018
Background Biomarkers of biological aging – DNA methylation age (DNAm age) and leukocyte telomere length (LTL)– correlate strongly with chronological age across the life course. It is, however, unclear how these measures of cellular wear and tear are associated with muscle strength and functional capacity, which are known to decline with older age and are associated with mortality. We investigated if DNAm age and LTL were associated with body composition and physical functioning by examining 48 monozygotic twin sisters. Methods White blood cell DNAm age (predicted years) was calculated from Illumina 450 k BeadChip methylation data using an online calculator. DNAm age acceleration was define…
Up-Regulation of leucocytes Genes Implicated in Telomere Dysfunction and Cellular Senescence Correlates with Depression and Anxiety Severity Scores
2012
BACKGROUND: Major depressive disorder (MDD) is frequently associated with chronic medical illness responsible of increased disability and mortality. Inflammation and oxidative stress are considered to be the major mediators of the allostatic load, and has been shown to correlate with telomere erosion in the leucocytes of MDD patients, leading to the model of accelerated aging. However, the significance of telomere length as an exclusive biomarker of aging has been questioned on both methodological and biological grounds. Furthermore, telomeres significantly shorten only in patients with long lasting MDD. Sensitive and dynamic functional biomarkers of aging would be clinically useful to eval…
Telomere Shortening in Neural Stem Cells Disrupts Neuronal Differentiation and Neuritogenesis
2009
Proliferation in the subependymal zone (SEZ) and neurogenesis in the olfactory bulb decline in the forebrain of telomerase-deficient mice. The present work reveals additional effects of telomere shortening on neuronal differentiation, as adult multipotent progenitors with critically short telomeres yield reduced numbers of neurons that, furthermore, exhibit underdeveloped neuritic arbors. Genetic data indicate that the tumor suppressor protein p53 not only mediates the adverse effects of telomere attrition on proliferation and self-renewal but it is also involved in preventing normal neuronal differentiation of adult progenitors with dysfunctional telomeres. Interestingly, progenitor cells …
Telomere attrition in peripheral blood mononuclear cells of children with alpha-1 antitrypsin deficiency
2015
Background: Our research group have demonstrated that oxidative stress (OS) is involved in the pathophysiology of alpha-1 antitrypsin deficiency (AATD) (Escribano A. et al. Thorax 2015;70:82-3). In addition, many evidences have shown that OS accelerates telomere shortening in several lung pathologies. Short telomeres have been associated to higher emphysema risk in COPD patients. Rationale: Since AATD is characterised by chronic OS, we hypothesise that telomere shortening would be accelerated in AATD patients and would be associated with higher risk of developing lung disease. Aims: To assess telomere length (TL) in AATD patients and to study its association with AAT phenotypes. Methods: TL…
Direct detection of repetitive, whole chromosome paint and telomere DNA probes by immunogold electron microscopy
1993
Biotinylated repetitive, whole chromosome paint and telomere DNA probes were investigated at the electron microscope level after non-isotopic in situ hybridization and direct immunogold detection. The protocol described allowed the visualization of a biotinylated chromosome 1 specific satellite DNA probe in the light microscope without silver intensification. This sensitive method was exploited to analyse factors contributing to signal strength in immunogold chromosome painting. Furthermore, it allowed us to investigate the distribution of (TTAGGG)n telomere repeats in human metaphase chromosomes and interphase nuclei. Telomeric and internal (TTAGGG)n repeats were detected at high spatial r…
Tumorigenic conversion of endothelial cells.
2003
Tumors of endothelial origin develop rarely. Until now, only two angiosarcoma (AS)-derived endothelial cell lines have been be isolated, ISO-HAS and AS-M. Both AS-derived endothelial cell lines presented the typical endothelial characteristics, such as the expression of CD31 and von Willebrand factor, but differed from normal endothelial cells in a nuclear expression of p53, in a delayed angiogenic reaction, and a reduced expression of caveolin. In addition, differences in the expression of cytokines and cell adhesion molecules responsive to proinflammatory stimuli were observed. While AS-M showed an expression pattern similar to that of human umbilical vein endothelial cells (HUVEC), ISO-H…
The inner nuclear membrane protein Src1 associates with subtelomeric genes and alters their regulated gene expression
2008
Inner nuclear membrane proteins containing a LEM (LAP2, emerin, and MAN1) domain participate in different processes, including chromatin organization, gene expression, and nuclear envelope biogenesis. In this study, we identify a robust genetic interaction between transcription export (TREX) factors and yeast Src1, an integral inner nuclear membrane protein that is homologous to vertebrate LEM2. DNA macroarray analysis revealed that the expression of the phosphate-regulated genes PHO11, PHO12, and PHO84 is up-regulated in src1Δ cells. Notably, these PHO genes are located in subtelomeric regions of chromatin and exhibit a perinuclear location in vivo. Src1 spans the nuclear membrane twice an…
Forever Young: Structural Stability of Telomeric Guanine Quadruplexes in the Presence of Oxidative DNA Lesions**
2021
International audience; Human telomeric DNA, in G-quadruplex (G4) conformation, is characterized by a remarkable structural stability that confers it the capacity to resist to oxidative stress producing one or even clustered 8-oxoguanine (8oxoG) lesions. We present a combined experimental/computational investigation, by using circular dichroism in aqueous solutions, cellular immunofluorescence assays and molecular dynamics simulations, that identifies the crucial role of the stability of G4s to oxidative lesions, related also to their biological role as inhibitors of telomerase, an enzyme overexpressed in most cancers associated to oxidative stress.