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1.
J Sleep Res ; : e14274, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39054789

RESUMO

As the chronological age increases, there is a decrease in the telomere length (TL). Associations between TL and age-related diseases have been described. Since the major pathophysiological factors related to inadequate sleep (including sleep complaints and sleep disorders) contribute to the exacerbation of inflammation and oxidative stress, an association of sleep and TL has been proposed. The aim of this study was to evaluate the association between sleep-related variables with TL in a longitudinal framework. We used data derived from the EPISONO cohort, which was followed over 8 years. All individuals answered sleep-related questionnaires, underwent a full-night polysomnography (PSG), and had their blood collected for DNA extraction. The TL was measured through a quantitative real time polymerase chain reaction. Age, sex, body mass index (BMI), smoking, physical activity status, and the 10 principal components (ancestry estimate) were considered covariables. Of the 1042 individuals in the EPISONO cohort, 68.3% agreed to participate in the follow-up study (n = 712). Baseline SpO2 (ß = 0.008, p = 0.007), medium SpO2 (ß = 0.013, p = 0.013), and total sleep time <90% (ß = -0.122, p = 0.012) had an effect on TL from the follow-up. The 8 year TL attrition was inversely associated with total sleep time, sleep efficiency, sleep architecture variables, wake after sleep onset, arousal index, oxygen-related variables baseline, and the presence of obstructive sleep apnea (OSA). We conclude that individuals with worse sleep quality, alterations in sleep architecture, and OSA had greater TL attrition over the 8 years. Using a longitudinal approach, these findings confirm previous cross-sectional evidence linking sleep with accelerated biological ageing.

2.
Rev. Asoc. Méd. Argent ; 137(1): 4-10, mar. 2024.
Artigo em Espanhol | LILACS | ID: biblio-1552830

RESUMO

Se exponen los hallazgos históricos y la importancia biológica de los telómeros en la vida celular y en los aspectos genéticos del ADN humano. (AU)


The discovery and the biological importance of the telomeres are exposed. (AU)


Assuntos
Humanos , DNA/genética , Telômero/fisiologia , Telômero/genética , Telomerase/fisiologia , Telomerase/genética , Envelhecimento/fisiologia , DNA/metabolismo , Senescência Celular , Telomerase/metabolismo , Replicação do DNA/fisiologia , Encurtamento do Telômero , Neoplasias/fisiopatologia
3.
Rejuvenation Res ; 27(2): 44-50, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38279807

RESUMO

Despite current literature pointing to a link between shortened telomeres and aging, chronic diseases, and geriatric syndromes, the precise implications of this connection remain unclear. The aim of this exploratory, cross-sectional, observational study was to investigate the association between the relative telomere length (RTL) of peripheral blood leukocyte subtypes (mononuclear cells and granulocytes) and physical performance using the Short Physical Performance Battery (SPPB) in older adults. A cohort of 95 participants was recruited, which included men and women aged over 60 years (70.48 ± 5.5 years). It was found that mononuclear cell RTL was significantly lower than that of granulocytes (p < 0.0001). Moreover, individuals with good SPPB performance exhibited lower mononuclear cell RTL compared with those with moderate or poor performance. However, no significant differences were observed in granulocyte RTL between different SPPB performance groups. The global SPPB score showed an inverse correlation with mononuclear cell RTL, but this correlation was not present with granulocyte RTL. Similarly, the SPPB sit-to-stand domain correlated with mononuclear cell RTL, but no such correlation was found with granulocyte RTL. Our findings challenge conventional expectations, suggesting that shorter mononuclear cell RTL may be associated with favorable functional capacity. The variations in RTL between mononuclear cells and granulocytes highlight their distinct biological roles and turnover rates. A history of immune responses may influence mononuclear cell RTL dynamics, while telomerase activity may protect granulocyte RTL from significant shortening. The unexpected associations observed in mononuclear cell RTL emphasize the complex interplay between immune responses, cellular aging, and functional capacity in older adults.


Assuntos
Envelhecimento , Leucócitos , Masculino , Humanos , Feminino , Idoso , Pessoa de Meia-Idade , Estudos Transversais , Encurtamento do Telômero , Telômero , Desempenho Físico Funcional
4.
São Paulo med. j ; São Paulo med. j;142(5): e2023140, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1560550

RESUMO

ABSTRACT BACKGROUND: The human telomerase reverse transcriptase (hTERT) enzyme, encoded by the hTERT gene, synthesizes protective telomeric sequences on chromosomes and plays a fundamental role in cancer formation. Methylation of the hTERT gene has an upregulatory effect, increasing hTERT enzyme synthesis and allowing continuous tumor cell division. OBJECTIVE: In a group of patients with breast cancer, we aimed to analyze the methylation status of hTERT in the tumor, surrounding tissue, and circulating free deoxyribonucleic acid (cfDNA) of blood collected on the day of mastectomy and then approximately one year later. DESIGN AND SETTING: A prospective study was conducted at a university hospital in Rio de Janeiro, Brazil. METHODS: Samples were collected from 15 women with breast cancer on the day of mastectomy and approximately one year postoperatively. cfDNA was analyzed by sodium bisulfite conversion, followed by polymerase chain reaction, electrophoresis, and silver nitrate staining. RESULTS: Methylation of hTERT was detected in the tumors and surrounding tissues of all 15 patients. Five patients displayed hTERT methylation in the cfDNA from the blood of the first collection. Of the ten patients who returned for the second collection, three showed methylation. Two patients with methylation in the first collection did not display methylation in the second collection. One patient with no methylation in the first collection displayed methylation in the second collection, and one patient had a diminished level of methylation in the second collection. CONCLUSION: Only one-third of patients displayed methylation in their cfDNA, which may be related to the success of chemotherapy.

6.
J Mol Cell Biol ; 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37771090

RESUMO

Although mechanisms of telomere protection are well-defined in differentiated cells, it is poorly understood how stem cells sense and respond to telomere dysfunction. In particular, the broader impact of telomeric double-strand breaks (DSBs) in these cells is poorly characterized. Here, we report on DNA damage signaling, cell cycle, and transcriptome-level changes in human induced pluripotent stem cells (iPSCs) in response to telomere-internal DSBs. We engineered human iPSCs with an inducible TRF1-FokI fusion protein to acutely induce DSBs at telomeres. Using this model, we demonstrate that TRF1-FokI DSBs activate an ATR-dependent DDR, which leads to p53-independent cell cycle arrest in G2. Using CRISPR-Cas9 to cripple the catalytic domain of telomerase, we show that telomerase is largely dispensable for survival and lengthening of TRF1-FokI-cleaved telomeres, which instead are effectively repaired by robust homologous recombination (HR). In contrast to HR-based telomere maintenance in mouse embryonic stem cells, we find neither evidence that HR causes extension of telomeres beyond their initial lengths, nor an apparent role for ZSCAN4 in this process. Rather, HR-based repair of telomeric breaks is sufficient to maintain iPSC telomeres at a normal length which is compatible with sustained survival of the cells over several days of TRF1-FokI induction. Our findings suggest a previously unappreciated role for HR in telomere maintenance in telomerase-positive iPSCs and reveal distinct iPSC-specific responses to targeted telomeric damage.

7.
Heliyon ; 9(8): e18239, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37576279

RESUMO

Longevity has been a topic of interest since the beginnings of humanity, yet its aetiology and precise mechanisms remain to be elucidated. Aging is currently viewed as a physiological phenomenon characterized by the gradual degeneration of organic physiology and morphology due to the passage of time where both external and internal stimuli intervene. The influence of intrinsic factors, such as progressive telomere shortening, genome instability due to mutation buildup, the direct or indirect actions of age-related genes, and marked changes in epigenetic, metabolic, and mitochondrial patterns constitute a big part of its underlying endogenous mechanisms. On the other hand, several psychosocial and demographic factors, such as diet, physical activity, smoking, and drinking habits, may have an even more significant impact on shaping the aging process. Consequentially, implementing dietary and exercise patterns has been proposed as the most viable alternative strategy for attenuating the most typical degenerative aging changes, thus increasing the likelihood of prolonging lifespan and achieving successful aging.

8.
Eur J Haematol ; 111(3): 423-431, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37259830

RESUMO

BACKGROUND: Telomere biology diseases (TBD) result from defective telomere maintenance, leading to bone marrow failure. The only curative treatment for aplastic anemia related to TBD is a hematopoietic cell transplant (HCT). Although reduced-intensity conditioning (RIC) regimens decrease transplant-related mortality, non-hematological phenotypes represent a major challenge and are associated with poor long-term follow-up outcomes. OBJECTIVE: To describe the outcome of TBD patients transplanted for marrow failure. STUDY DESIGN: This is a retrospective, single-center study describing the outcomes of 32 consecutive transplants on 29 patients between 1993 and 2019. RESULTS: The median age at transplantation was 14 years (range, 3-30 years). Most patients received a RIC regimen (n = 28) and bone marrow (BM) from an unrelated donor (n = 16). Four patients received a haploidentical transplant. Chimerism was available for 27 patients with a median time to neutrophil recovery of 20 days (13-36 days). Primary graft failure occurred in one patient, whereas second graft failure occurred in two. Acute GVHD grade II-IV and moderate to severe chronic GVHD occurred in 22% of patients at risk. Fourteen patients were alive after HCT at the last follow-up (median, 6 years; 1.4-19 years). The 5-year overall survival was better after matched sibling donor (MSD) transplantation compared to other hematopoietic stem cell sources (88.9% vs. 47.7%; p = .05; CI = 95%). Overall, 15 patients died after HCT, most of them (n = 11) after the first year of transplant, due to non-hematological disease progression or complication of chronic GVHD. CONCLUSIONS: Hematopoietic cell transplantation is a potentially curative treatment option for TBD, nonetheless the poor outcome reflects the progression of non-hematologic disease manifestations, which should be considered when transplantation is indicated.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Estudos Retrospectivos , Estudos de Coortes , Doença Enxerto-Hospedeiro/etiologia , Doadores não Relacionados , Telômero/genética , Biologia , Condicionamento Pré-Transplante/efeitos adversos
9.
Curr Oncol ; 30(4): 4094-4109, 2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37185424

RESUMO

HER2-enriched tumors are responsible for 20% of breast tumors and have high rates of immune infiltrates in the tumor stroma that respond favorably to neoadjuvant chemotherapy. In the context of tumors, telomeres control cell death and prevent tumor cells from replicating discontinuously, leading to their immortalization. This study aimed to evaluate the presence of tumor-infiltrating lymphocytes, hTERT expression, hTERT promoter mutation, and leukocyte telomere length in HER2-enriched breast tumors. A total of 103 cases were evaluated, 19 with pathologic complete response. The TILs percentage was above ≥10 in 44 cases (43%) and significantly present in patients ≥50 years of age. hTERT staining positivity was mostly nuclear, significantly present in the non-pCR group, and associated with a lower survival rate. Leukocyte telomeres were elongated for HER2-enriched tumors, and in multivariate analysis, shortening was associated with an increased risk of death. Overall, our results show that the nuclear and cytoplasmic presence of hTERT may indicate a worse prognosis and that leukocyte telomere elongation is a protective factor.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Terapia Neoadjuvante/métodos , Prognóstico , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo
10.
Front Biosci (Landmark Ed) ; 28(4): 73, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37114543

RESUMO

BACKGROUND: The motivations for and effects of ethanol consumption vary considerably among individuals, and as such, a significant proportion of the population is prone to substance abuse and its negative consequences in the physical, social, and psychological spheres. In a biological context, the characterization of these phenotypes provides clues for understanding the neurological complexity associated with ethanol abuse behavior. Therefore, the objective of this research was to characterize four ethanol preference phenotypes described in zebrafish: Light, Heavy, Inflexible, and Negative Reinforcement. METHODS: To do this, we evaluated the telomere length, mtDNA copy number using real-time quantitative PCR (qPCR), and the activity of these antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the brain, and the interactions between these biomarkers. Changes observed in these parameters were associated with ethanol consumption and alcohol abuse. RESULTS: The Heavy, Inflexible, and Negative Reinforcement phenotypes showed ethanol preference. This was particularly the case with the Inflexible phenotype, which was the group with the greatest ethanol preference. These three phenotypes showed telomere shortening as well as high SOD/CAT and/or GPx activities, while the Heavy phenotype also showed an increase in the mtDNA copy number. However, the Light phenotype, containing individuals without ethanol preference, did not demonstrate any changes in the analyzed parameters even after being exposed to the drug. Additionally, the PCA analysis showed a tendency to cluster the Light and Control groups differently from the other ethanol preference phenotypes. There was also a negative correlation between the results of the relative telomere length and SOD and CAT activity, providing further evidence of the biological relationship between these parameters. CONCLUSIONS: Our results showed differential molecular and biochemistry patterns in individuals with ethanol preference, suggesting that the molecular and biochemical basis of alcohol abuse behavior extends beyond its harmful physiological effects, but rather is correlated with preference phenotypes.


Assuntos
Alcoolismo , Antioxidantes , Animais , Antioxidantes/farmacologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Variações do Número de Cópias de DNA , Catalase/genética , Catalase/metabolismo , Catalase/farmacologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Etanol , Encéfalo/metabolismo , Mitocôndrias/metabolismo , DNA Mitocondrial/genética , Telômero/genética , Telômero/metabolismo , Estresse Oxidativo
11.
BioTech (Basel) ; 12(1)2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36810441

RESUMO

Somatic human cells can divide a finite number of times, a phenomenon known as the Hayflick limit. It is based on the progressive erosion of the telomeric ends each time the cell completes a replicative cycle. Given this problem, researchers need cell lines that do not enter the senescence phase after a certain number of divisions. In this way, more lasting studies can be carried out over time and avoid the tedious work involved in performing cell passes to fresh media. However, some cells have a high replicative potential, such as embryonic stem cells and cancer cells. To accomplish this, these cells express the enzyme telomerase or activate the mechanisms of alternative telomere elongation, which favors the maintenance of the length of their stable telomeres. Researchers have been able to develop cell immortalization technology by studying the cellular and molecular bases of both mechanisms and the genes involved in the control of the cell cycle. Through it, cells with infinite replicative capacity are obtained. To obtain them, viral oncogenes/oncoproteins, myc genes, ectopic expression of telomerase, and the manipulation of genes that regulate the cell cycle, such as p53 and Rb, have been used.

12.
World J Clin Cases ; 10(33): 12440-12446, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36483815

RESUMO

BACKGROUND: Dyskeratosis congenita is a rare disease characterized by bone marrow failure and a clinical triad of oral leukoplakia, nail dystrophy, and abnormal skin pigmentation. The genetics of dyskeratosis congenita include mutations in genes involved in telomere maintenance, including TINF2. CASE SUMMARY: Here, we report a female patient who presented thrombocytopenia, anemia, reticulate hyperpigmentation, dystrophy in fingernails and toenails, and leukoplakia on the tongue. A histopathological study of the skin showed dyskeratocytes; however, a bone marrow biopsy revealed normal cell morphology. The patient was diagnosed with dyskeratosis congenita, but her family history did not reveal significant antecedents. Whole-exome sequencing showed a novel heterozygous punctual mutation in exon 6 from the TINF2 gene, namely, NM_001099274.1:c.854delp.(Val285Alafs*32). An analysis of telomere length showed short telomeres relative to the patient's age. CONCLUSION: The disease in this patient was caused by a germline novel mutation of TINF2 in one of her parents.

13.
Arq. ciências saúde UNIPAR ; 26(3): 1229-1247, set-dez. 2022.
Artigo em Português | LILACS | ID: biblio-1414495

RESUMO

Mesmo em tempos modernos, os grandes avanços tecnológicos não permitem de forma comprovada retardar o envelhecimento nos seres humanos. Neste sentido, uma das estratégias é o uso moléculas químicas naturais que possuem a ação de ativadores de telomerase, uma vez de que a telomerase é uma ribonucleoproteína transcriptase reversa que possui a função de alongar os telômeros e neutralizar a erosão normal dos telômeros. Neste contexto, este estudo de revisão dedicou-se a aprofundar o conhecimento sobre o uso de moléculas químicas naturais derivadas de plantas que possuem função de ativadores de telomerase para atividade anti-aging. Inúmeras moléculas têm sido propostas e, estudas os seus mecanismos com o intuito de desenvolver novas ferramentas para prevenir/retardar e tratar doenças relacionadas a idade e o envelhecimento. Adicionalmente, o uso de moléculas como ativadores da telomerase têm sido um meio de prolongar o encurtamento dos temoleros, como no caso, de moléculas isolada da erva Astragalus membranaceus (TA-65), curcumina, silbinina e alicina; ademais, outras moléculas de origem natural possuem atividade anti-aging comprovadas, conforme reportadas nesta revisão. Sendo assim, a procura por biomarcadores à base de compostos químicos naturais que estimulem a telomerase, a fim de prolongar a vida dos telômero e assim, retardar o processo de envelhecimento do organismo têm despertado o interesse de diversos pesquisadores ao redor do mundo.


Even in modern times, the great technological advances do not allow in a proven way to delay aging in humans. In this sense, one of the strategies is the use of natural chemical molecules that have telomerase activators, since telomerase is a ribonucleoprotein reverse transcriptase that has the function of lengthening telomeres and neutralizing the normal erosion of telomeres. In this context, this review study was dedicated to deepening the knowledge about the use of natural chemical molecules derived from plants that have telomerase activator function for anti-aging activity. Numerous molecules have been proposed and their mechanisms studied in order to develop new tools to prevent/delay and treat aging-related diseases. Additionally, the use of molecules as telomerase activators has been a means of prolonging the shortening of temolers, as in the case of molecules isolated from the herb Astragalus membranaceus (TA-65), curcumin, silbinin and allicin; in addition, other molecules of natural origin have proven anti-aging activity, as reported in this review. Therefore, the search for biomarkers based on natural chemical compounds that stimulate telomerase in order to prolong the life of telomeres and, thus delay the aging process of the organism has aroused the interest of several researchers around the world.


Aún en los tiempos modernos, los grandes avances tecnológicos no permiten de manera comprobada retrasar el envejecimiento en los humanos. En este sentido, una de las estrategias es el uso de moléculas químicas naturales que tengan activadores de la telomerasa, ya que la telomerasa es una ribonucleoproteína transcriptasa inversa que tiene la función de alargar los telómeros y neutralizar la erosión normal de los telómeros. En este contexto, este estudio de revisión se dedicó a profundizar en el conocimiento sobre el uso de moléculas químicas naturales derivadas de plantas que tienen función activadora de la telomerasa para la actividad antienvejecimiento. Se han propuesto numerosas moléculas y se han estudiado sus mecanismos para desarrollar nuevas herramientas para prevenir/retrasar y tratar enfermedades relacionadas con el envejecimiento. Adicionalmente, el uso de moléculas como activadores de la telomerasa ha sido un medio para prolongar el acortamiento de temolers, como es el caso de moléculas aisladas de la hierba Astragalus membranaceus (TA-65), curcumina, silbinina y alicina; además, otras moléculas de origen natural han demostrado actividad antienvejecimiento, como se reporta en esta revisión. Por ello, la búsqueda de biomarcadores basados en compuestos químicos naturales que estimulen la telomerasa para prolongar la vida de los telómeros y así retrasar el proceso de envejecimiento del organismo ha despertado el interés de varios investigadores a nivel mundial.


Assuntos
Produtos Biológicos , Envelhecimento/efeitos dos fármacos , Telomerase , DNA , Telômero , Astragalus propinquus , Curcuma/efeitos dos fármacos
14.
Genome ; 65(11): 563-572, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36044774

RESUMO

The genus Ctenomys has been widely used in karyotype evolution studies due to the variation in their diploid numbers. Ctenomys minutus is characterized by intraspecific variation in diploid number (2n = 42, 46, 48, and 50), which makes it an interesting model to investigate genomic rearrangements mechanisms that could lead to different cytotypes in this species. Thereupon, it has been already shown that DNA methylation may participate in chromosome structure. Therefore, we aimed to investigate whether telomeres and global DNA methylation had a role in the genome rearrangements that led to this variation in C. minutus. We also realized an analysis for the presence of intrachromosomal telomeric repeats (ITRs) by fluorescence in situ hybridization. Our study demonstrated that neither telomere length nor DNA methylation had significant differences among the cytotypes. However, if only females were considered, there were significant differences for telomere length and methylation. Young individuals, regardless of their cytotypes, had the most methylated DNA. Regarding the ITRs, we found a signal on chromosome 1 in 2n = 50b. No evidence was found that telomere length or methylation could have influenced chromosomal rearrangements, although new cytotypes seem to have emerged within the distribution of parental cytotypes by the accumulation of different chromosomal rearrangements.


Assuntos
Roedores , Telômero , Humanos , Animais , Hibridização in Situ Fluorescente , Metilação , Cariótipo , Cariotipagem , Roedores/genética , Telômero/genética
15.
AIDS Rev ; 25(2): 79-86, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35901108

RESUMO

Aging, a time-dependent loss of physiological function, and its drivers are turning into a significant topic of researchas the population's mean age increases. Epigenetic alterations, telomere shortening or dysfunction, mitogenic stress,oxidative stress, or accumulation of DNA damage can drive the cell to senescence a permanent cell cycle arrest sometimes associated with a secretory phenotype and inflammatory consequences in the surrounding tissue. The amount of senescent cellsgrows over time in older organisms and may induce tissue inflammation and threaten overall tissue homeostasis, favoring aging. Senolytic and senomorphic therapeuticsare an emerging approach to eliminate senescent cells or to block their secretoryphenotypes respectively. Given that people living with HIV suffer non-AIDS comorbidities in a higher prevalence than the general population, aging is accentuated among them. Inflammation biomarkers may be helpful to assess prognosis or act as surrogate endpoints for studies of strategies focused on reversal of HIV-associated accelerated aging. This review summarizes the latest findings in aging and its major drivers, under the light of HIV infection. Since the number of older PLWH is currently rising, it will be of great importance to address and treat their age-related conditions, as well as to better decipher their biological mechanisms.


Assuntos
Senescência Celular , Infecções por HIV , Envelhecimento , Biomarcadores , Senescência Celular/genética , Infecções por HIV/tratamento farmacológico , Humanos , Inflamação
17.
Front Psychol ; 13: 712660, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35282254

RESUMO

Introduction: Stress is associated with disease and reduced leukocyte telomere length (LTL). The objective of this research is to determine if self-perceived stress is associated with telomere length in Costa Rican adults and the gender differences in this association. Findings may help explain how some populations in apparent socioeconomic disadvantage and with limited access to specialized medical services have a remarkably high life expectancy. Methodology: Data come from the pre-retirement cohort of the Costa Rican Longevity and Healthy Aging Study (CRELES), a population based survey conducted in the households to 2,327 adults aged 53 to 66 years. The DNA to measure LTL was extracted from blood cells in laboratories of the University of Costa Rica whereas the Blackburn laboratory at the University of California performed the telomere length measurement applying the quantitative polymerase chain reaction (Q-PCR). The relationship between telomere length and perceived stress was measured using least-squares multiple regression. Perceived stress was measured by a set of questions about family, job, finances and, health reasons to be stressed. Models included the control variables: (1) age and sex of the participant, (2) whether he or she resides in the Nicoya area, a "blue zone" known for its high longevity, and (3) the aforementioned sociodemographic, health and lifestyles characteristics. Results: Stress perception and LTL are significantly different by sex. Women perceived higher stress levels than men in almost all aspects studied, except work. Women have significantly longer telomeres. Shorter telomeres are significantly associated with caregiving stress in men and with parental health concerns in women. Counter-intuitive telomere lengthenings were observed among women who feel stressed about caring for family members; and among men who feel stressed due to their family relationships as well as concerns about their own health. Discussion: Results confirm that people with self-perceived stress due to caregiving or health issues have shorter telomeres. The relationship between stress and telomere length differs between men and women. Gender relations exert a strong modifier effect on the relationship between stress and LTL: gender is related to perceived stress, telomere length, and apparently also to the way stress and LTL are related.

18.
Chromosoma ; 131(1-2): 59-75, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35325297

RESUMO

A substantial portion of the eukaryotic genome includes repetitive DNA, which is important for its stability, regulation, and architecture. Fungus-farming ant genomes show remarkable structural rearrangement rates that were necessary for the establishment of their agriculture-based lifestyle, highlighting the relevance of this peculiar group in understanding the repetitive portion of ant genome. Chromosomal banding studies are in accordance with genomic data because they show that repetitive heterochromatic sequences of basal and derivative Attina species are GC-rich, an uncommon trait in Formicidae. To understand the evolutionary dynamics of heterochromatin in Attina, we compared GC-rich heterochromatin patterns between the Paleoattina and Neoattina clades of this subtribe. To this end, we hybridized the Mrel-C0t probe (highly and moderately repetitive DNA) obtained from Mycetomoellerius relictus, Neoattina with GC-rich heterochromatin, in karyotypes of Paleoattina and Neoattina species. Additionally, we mapped the repetitive sequences (GA)15 and (TTAGG)6 in species of the two clades to investigate their organization and evolutionary patterns in the genome of Attina. The Mrel-C0t probe marked the heterochromatin in M. relictus, in other Mycetomoellerius spp., and in species of Mycetarotes, Cyphomyrmex, and Sericomyrmex (Neoattina). In Mycetomoellerius urichii, only pericentromeric heterochromatin was marked with Mrel-C0t. No marking was observed in Paleoattina species or in Atta and Acromyrmex (Neoattina). These results indicated that different evolutionary events led to heterochromatin differentiation in Attina. The most likely hypothesis is that GC-rich heterochromatin arose in the common ancestor of the two clades and accumulated various changes throughout evolution. The sequences (GA)15 and (TTAGG)6 located in euchromatin and telomeres, respectively, showed more homogeneous results among the species.


Assuntos
Formigas , Heterocromatina , Agricultura , Animais , Formigas/genética , DNA , Fungos/genética , Heterocromatina/genética , Sequências Repetitivas de Ácido Nucleico
19.
Int J Mol Sci ; 23(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35328692

RESUMO

The long noncoding RNA (lncRNA) telomeric repeat-containing RNA (TERRA) has been associated with telomeric homeostasis, telomerase recruitment, and the process of chromosome healing; nevertheless, the impact of this association has not been investigated during the carcinogenic process. Determining whether changes in TERRA expression are a cause or a consequence of cell transformation is a complex task because studies are usually carried out using either cancerous cells or tumor samples. To determine the role of this lncRNA in cellular aging and chromosome healing, we evaluated telomeric integrity and TERRA expression during the establishment of a clone of untransformed myeloid cells. We found that reduced expression of TERRA disturbed the telomeric homeostasis of certain loci, but the expression of the lncRNA was affected only when the methylation of subtelomeric bivalent chromatin domains was compromised. We conclude that the disruption in TERRA homeostasis is a consequence of cellular transformation and that changes in its expression profile can lead to telomeric and genomic instability.


Assuntos
RNA Longo não Codificante , Homeostase do Telômero , Cromatina/genética , Heterocromatina , Metilação , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Telômero/genética , Telômero/metabolismo
20.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;55: e12072, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1384151

RESUMO

Constitutional genomic imbalances are known to cause malformations, disabilities, neurodevelopmental delay, and dysmorphia and can lead to dysfunctions in the cell cycle. In extremely rare genetic conditions such as small supernumerary marker chromosomes (sSMC), it is important to understand the cellular consequences of this extra marker, as well the factors that contribute to their maintenance or elimination through successive cell cycles and phenotypic impact. The study of chromosomal mosaicism provides a natural model to characterize the effect of aneuploidy on genome stability and compare cells with the same genetic background and environment exposure, but differing in the presence of sSMC. Here, we report the functional characterization of different cell lines from two familial patients with mosaic sSMC derived from chromosome 12. We performed studies of proliferation dynamics, stability, and variability of these cells using fluorescent in situ hybridization (FISH), sister chromatid exchanges (SCE), and conventional staining. We also quantified the telomere-related genomic instability of sSMC cells using 3D telomeric profile analysis by quantitative-FISH. sSMC cells exhibited differences in the cell cycle dynamics compared to normal cells. First, the sSMC cells exhibited lower proliferation index and higher frequency of SCE than normal cells, associated with a higher level of chromosomal instability. Second, sSMC cells exhibited more telomeric-related genomic instability. Lastly, the differences of sSMC cells distribution among tissues could explain different phenotypic repercussions observed in patients. These results will help in our understanding of the sSMC stability, maintenance during cell cycle, and the cell cycle variables involved in the different phenotypic manifestations.

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