Telomere aberrations, including telomere loss, doublets, and extreme shortening, are increased in patients with infertility

2021 ◽  
Vol 115 (1) ◽  
pp. 164-173 ◽  
Author(s):  
Radhia M’kacher ◽  
Bruno Colicchio ◽  
Valentine Marquet ◽  
Claire Borie ◽  
Wala Najar ◽  
...  
Keyword(s):  
Telomere Loss

Telomere loss, not average telomere length, confers radiosensitivity to TK6-irradiated cells

2012 ◽  
Vol 740 (1-2) ◽  
pp. 13-20 ◽  
Author(s):  
F. Berardinelli ◽  
D. Nieri ◽  
A. Sgura ◽  
C. Tanzarella ◽  
A. Antoccia
Keyword(s):  
Telomere Length ◽  
Telomere Loss

scholarly journals Somatic growth and telomere dynamics in vertebrates: relationships, mechanisms and consequences

2018 ◽  
Vol 373 (1741) ◽  
pp. 20160446 ◽  
Author(s):  
Pat Monaghan ◽  
Susan E. Ozanne
Keyword(s):  
Cell Proliferation ◽  
Somatic Growth ◽  
Growth Strategy ◽  
Theme Issue ◽  
Confounding Variables ◽  
Telomere Loss ◽  
The Relationship ◽  
Telomere Dynamics

Much telomere loss takes place during the period of most rapid growth when cell proliferation and potentially energy expenditure are high. Fast growth is linked to reduced longevity. Therefore, the effects of somatic cell proliferation on telomere loss and cell senescence might play a significant role in driving the growth-lifespan trade-off. While different species will have evolved a growth strategy that maximizes lifetime fitness, environmental conditions encountered during periods of growth will influence individual optima. In this review, we first discuss the routes by which altered cellular conditions could influence telomere loss in vertebrates, with a focus on oxidative stress in both in vitro and in vivo studies. We discuss the relationship between body growth and telomere length, and evaluate the empirical evidence that this relationship is generally negative. We further discuss the potentially conflicting hypotheses that arise when other factors are taken into account, and the further work that needs to be undertaken to disentangle confounding variables. This article is part of the theme issue ‘Understanding diversity in telomere dynamics’.

scholarly journals EXO1 resection at G-quadruplex structures facilitates resolution and replication

2020 ◽  
Vol 48 (9) ◽  
pp. 4960-4975 ◽  
Author(s):  
Susanna Stroik ◽  
Kevin Kurtz ◽  
Kevin Lin ◽  
Sergey Karachenets ◽  
Chad L Myers ◽  
...  
Keyword(s):  
Dna Replication ◽  
Genomic Instability ◽  
Secondary Structures ◽  
Replication Forks ◽  
End Joining ◽  
G Quadruplex ◽  
Exonuclease 1 ◽  
Telomere Loss

Abstract G-quadruplexes represent unique roadblocks to DNA replication, which tends to stall at these secondary structures. Although G-quadruplexes can be found throughout the genome, telomeres, due to their G-richness, are particularly predisposed to forming these structures and thus represent difficult-to-replicate regions. Here, we demonstrate that exonuclease 1 (EXO1) plays a key role in the resolution of, and replication through, telomeric G-quadruplexes. When replication forks encounter G-quadruplexes, EXO1 resects the nascent DNA proximal to these structures to facilitate fork progression and faithful replication. In the absence of EXO1, forks accumulate at stabilized G-quadruplexes and ultimately collapse. These collapsed forks are preferentially repaired via error-prone end joining as depletion of EXO1 diverts repair away from error-free homology-dependent repair. Such aberrant repair leads to increased genomic instability, which is exacerbated at chromosome termini in the form of dysfunction and telomere loss.

scholarly journals Telomere loss in relation to age and early environment in long-lived birds

2004 ◽  
Vol 271 (1548) ◽  
pp. 1571-1576 ◽  
Author(s):  
Margaret E. Hall ◽  
Lubna Nasir ◽  
Francis Daunt ◽  
Elizabeth A. Gault ◽  
John P. Croxall ◽  
...  
Keyword(s):  
Early Environment ◽  
Telomere Loss

scholarly journals Progressive Telomere Shortening in Aplastic Anemia

Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3582-3592 ◽  
Author(s):  
Sarah E. Ball ◽  
Frances M. Gibson ◽  
Siân Rizzo ◽  
Jennifer A. Tooze ◽  
Judith C.W. Marsh ◽  
...  
Keyword(s):  
Aplastic Anemia ◽  
Late Complication ◽  
Blood Leukocytes ◽  
Telomere Shortening ◽  
Hematopoietic Stem ◽  
Age Related ◽  
High Incidence ◽  
Telomere Loss ◽  
Cell Fractions ◽  
Telomere Erosion

Abstract Improved survival in aplastic anemia (AA) has shown a high incidence of late clonal marrow disorders. To investigate whether accelerated senescence of hematopoietic stem cells might underlie the pathophysiology of myelodysplasia (MDS) or paroxysmal nocturnal hemoglobinuria (PNH) occurring as a late complication of AA, we studied mean telomere length (TRF) in peripheral blood leukocytes from 79 patients with AA, Fanconi anemia, or PNH in comparison with normal controls. TRF lengths in the patient group were significantly shorter for age than normals (P < .0001). Telomere shortening was apparent in both granulocyte and mononuclear cell fractions, suggesting loss at the level of the hematopoietic stem cell. In patients with acquired AA with persistent cytopenias (n = 40), there was significant correlation between telomere loss and disease duration (r = −.685; P < .0001), equivalent to progressive telomere erosion at 216 bp/yr, in addition to the normal age-related loss. In patients who had achieved normal full blood counts (n = 20), the rate of telomere loss had apparently stabilised. There was no apparent association between telomere loss and secondary PNH (n = 13). However, of the 5 patients in the study with TRF less than 5.0 kb, 3 had acquired cytogenetic abnormalities, suggesting that telomere erosion may be relevant to the pathogenesis of MDS in aplastic anemia.

Mathematical model and computer simulations of telomere loss

2019 ◽  
Vol 465 ◽  
pp. 78-89 ◽  
Author(s):  
Ana Martinčić Špoljarić ◽  
Ivica Rubelj ◽  
Miljenko Huzak
Keyword(s):  
Mathematical Model ◽  
Computer Simulations ◽  
Telomere Loss

scholarly journals Telomere and Centromere Staining Followed by M-FISH Improves Diagnosis of Chromosomal Instability and Its Clinical Utility

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 475 ◽  
Author(s):  
Radhia M’kacher ◽  
Bruno Colicchio ◽  
Claire Borie ◽  
Steffen Junker ◽  
Valentine Marquet ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Cancer Progression ◽  
Chromosomal Instability ◽  
Fish Analysis ◽  
Telomere Dysfunction ◽  
Genetic Syndromes ◽  
Genetic Syndrome ◽  
Dicentric Chromosomes ◽  
Telomere Loss ◽  
Conventional Cytogenetics

Dicentric chromosomes are a relevant marker of chromosomal instability. Their appearance is associated with telomere dysfunction, leading to cancer progression and a poor clinical outcome. Here, we present Telomere and Centromere staining followed by M-FISH (TC+M-FISH) for improved detection of telomere dysfunction and the identification of dicentric chromosomes in cancer patients and various genetic syndromes. Significant telomere length shortening and significantly higher frequencies of telomere loss and deletion were found in the peripheral lymphocytes of patients with cancer and genetic syndromes relative to similar age-matched healthy donors. We assessed our technique against conventional cytogenetics for the detection of dicentric chromosomes by subjecting metaphase preparations to both approaches. We identified dicentric chromosomes in 28/50 cancer patients and 21/44 genetic syndrome patients using our approach, but only 7/50 and 12/44, respectively, using standard cytogenetics. We ascribe this discrepancy to the identification of the unique configuration of dicentric chromosomes. We observed significantly higher frequencies of telomere loss and deletion in patients with dicentric chromosomes (p < 10−4). TC+M-FISH analysis is superior to classical cytogenetics for the detection of chromosomal instability. Our approach is a relatively simple but useful tool for documenting telomere dysfunction and chromosomal instability with the potential to become a standard additional diagnostic tool in medical genetics and the clinic.

Telomere Length Among the Elderly and Oldest-Old

2005 ◽  
Vol 8 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Claus Bischoff ◽  
Jesper Graakjaer ◽  
Hans Christian Petersen ◽  
Bernard Jeune ◽  
Vilhelm A. Bohr ◽  
...  
Keyword(s):  
Telomere Length ◽  
Oldest Old ◽  
The Elderly ◽  
Specific Difference ◽  
Cross Sectional ◽  
Telomere Shortening ◽  
Telomere Sequence ◽  
Age Dependent ◽  
The Mean ◽  
Telomere Loss

AbstractHuman chromosomes terminate in a number of repeats of the sequence TTAGGG. At birth, each chromosome end is equipped with approximately 15 kb of telomere sequence, but this sequence is shortened during each cell division. In cell cultures telomere shortening is associated with senescence, a phenomenon that has also been observed in normal adult tissues, indicating that telomere loss is associated with organismal ageing. Previous work has established that the rate of telomere loss in humans is age dependent, and recent work shows a sex-specific difference in telomere length and shortening in individuals over the age span of 20 to 75 years. Here, terminal restriction fragment lengths on DNA purified from whole blood were measured to examine the mean telomere length in a cross-sectional cohort of 816 Danish individuals of age 73 to 101 years. In this age group, females show a linear correlation between telomere length and age, whereas the pattern tends to be nonlinear (quadratic in age) for males. This difference in telomere length dynamics between the 2 sexes may be caused by several different mechanisms, including differences in selection by mortality, differences in leukocyte population or different telomerase expression pattern.

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