Search Results (1,458)

Fusarium verticillioides is a globally prevalent phytopathogenic fungus responsible for multiple diseases in maize and a major producer of the mycotoxin fumonisin B1 (FB1), a highly toxic fungal secondary metabolite (FSM). The histone code, which includes reversible modifications such as acetylation and methylation, plays a critical role in regulating chromatin structure and gene expression. In fungi, di- and tri-methylation of histone H3 at lysine 9 (H3K9me2/3) serves as a key epigenetic mark associated with heterochromatin formation and transcriptional repression. In this study, we identified and characterized a putative heterochromatin protein 1 (HP1) family member in F. verticillioides, designated FvHP1, based on conserved domain architecture and phylogenetic analyses. FvHP1 retains essential residues required for H3K9me2/3 recognition, supporting its functional conservation within the HP1 protein family. Phenotypic analysis of the ΔFvHP1 mutant revealed impaired vegetative growth, reduced conidiation and virulence, and altered FB1 mycotoxin production. Additionally, the accumulation of red pigment in the mutant was linked to the deregulation of secondary metabolism, specifically the overproduction of fusarubin-type naphthoquinones, such as 8-O-methylnectriafurone. These results support the role of FvHP1 in facultative heterochromatin-mediated repression of sub-telomeric biosynthetic gene clusters, including the pigment-associated PGL1 cluster. Our findings provide new insights into the epigenetic regulation of fungal pathogenicity and metabolite production, as well as the first evidence of a functional HP1 homolog in F. verticillioides. Full article

The worldwide prevalence of obesity continues to increase, representing a serious public health issue due to associated comorbidities. Obesity is associated with type 2 diabetes mellitus (T2D), which shares similar pathophysiological mechanisms. In both conditions, oxidative stress, inflammation, mitochondrial dysfunction, abnormal adipose tissue function, and senescence are observed, ultimately leading to insulin resistance. In both cases, hypertrophic adipose tissue is associated with telomere shortening. Elucidating the mechanisms underlying telomere shortening in obesity and diabetes may be crucial for deepening our understanding of these pathologies, with the ultimate aim of its translational implications. Several studies have shown that telomere shortening is present in patients with metabolic disorders, emphasizing its prognostic value for the onset and progression of these diseases. From this perspective, this article highlights the importance of telomere biology, which can aid in developing new therapeutic options for metabolic disorders. Full article

Aging affects all tissues in an organism, including the tracheobronchial tree, with structural and functional changes driven by mechanisms such as oxidative stress, cellular senescence, epigenetic modifications, mitochondrial dysfunction, and telomere shortening. Airway aging can be accelerated by intrinsic or extrinsic factors. This review brings together information from the literature on the molecular changes occurring in all layers of the tracheobronchial airway wall. It examines the biomolecular changes associated with aging in the mucosa, submucosa, cartilage, and smooth muscle of the airways. At the mucosal level, aging reduces ciliary function and disrupts mucin homeostasis, impairing mucociliary clearance and contributing to chronic respiratory diseases such as COPD (Chronic Obstructive Pulmonary Disease). Cellular senescence and oxidative stress drive extracellular matrix remodeling and chronic inflammation. Airway cartilage undergoes age-related changes in collagen and fibronectin composition, leading to increased stiffness, while heightened MMP (Matrix Metalloproteinases) activity exacerbates ECM (extracellular matrix) degradation. In airway smooth muscle, aging induces changes in calcium signaling, hypertrophy, and the secretion of pro-inflammatory mediators, further perpetuating airway remodeling. These changes impair respiratory function and increase susceptibility to chronic respiratory conditions in the elderly. By consolidating current knowledge, this review aims to provide a comprehensive overview of the molecular changes occurring in the respiratory tract with aging and to highlight new molecular perspectives for future research on this topic. Full article

The conserved and essential Cdc13/CTC1-Stn1-Ten1 telomeric complex (CST) ensures chromosome stability by protecting telomere ends and regulating telomerase accessibility. In a recent study, we uncovered mutants of the S. cerevisiae CST, in which damage was sensed by the two major G2/M spindle checkpoints (one is Bub2-dependent and the other one Mad2-dependent), as well as the major G2/M DNA damage checkpoint (Mec1-dependent). In this study, we found, by fluorescence microscopy, that the stability of the mitotic tubulin spindle was profoundly affected in the best-studied of these mutants, stn1-sz2. Additional data from genetic analyses suggested the potential involvement of Stu1 and Stu2, as well as Slk19, in these defects. Throughout this study, we compared the phenotypes of stn1-sz2 with those of cdc13-1, the best-studied CST mutant, which also serves as a prototype of telomere-damage-characterized CST mutants. We propose that stn1-sz2 represents the prototype of cst mutants characterized by tubulin spindle damage. These newly described phenotypes potentially represent the basis for identifying new functions of the CST telomeric complex. These functions might consist of ensuring correct chromosome segregation through the stabilization of the mitotic spindle. Full article

Homologous recombination deficiency (HRD) is a key biomarker associated with increased sensitivity to PARP inhibitors (PARPi) in advanced epithelial ovarian cancer. Accurate identification of HRD status is essential for selecting patients most likely to benefit from these therapies. Current diagnostic approaches combine sequencing to detect mutations in homologous recombination repair genes—particularly BRCA1 and BRCA2—with genome-wide analysis of structural genomic alterations indicative of HRD. This review briefly outlines the biological basis of HRD and its clinical significance and then focuses on currently available assays for HRD assessment. We compare their molecular strategies, including the use of targeted gene panels and genomic instability metrics such as loss of heterozygosity, telomeric allelic imbalance, and large-scale state transitions. The review also highlights the strengths and limitations of each platform and discusses their role in guiding clinical decision-making. Challenges related to dynamic tumor evolution and the interpretation of HRD status in recurrent disease settings are also addressed. Full article

Socioeconomic factors have led an increasing number of women to postpone childbirth, thereby elevating the risks of reduced fertility, pregnancy complications, preterm birth, cesarean delivery, and chromosomal abnormalities. While diminished oocyte quality is a well-established contributor to age-related infertility, endometrial dysfunction also plays a pivotal role. Optimizing both oocyte quality and endometrial health is essential for enhancing reproductive outcomes. Although aging has been defined by twelve hallmarks, research specifically addressing age-related changes in endometrial function remains limited. This review examines the process of endometrial aging, with a particular emphasis on mitochondrial function. A comprehensive literature search was conducted using PubMed and Google Scholar to identify relevant studies published up to 31 January 2025. Endometrial aging is driven by multiple biological mechanisms, most notably the decline in endometrial receptivity. Key contributing factors include hormonal dysregulation, chronic inflammation, cell cycle arrest, genomic instability, epigenetic alterations, telomere attrition, and mitochondrial dysfunction. Among these, mitochondrial dysfunction emerges as a central driver of the aging process. Endometrial senescence, precipitated by irreversible mitochondrial impairment, may underlie the progressive decline in reproductive potential. Elucidating the role of mitochondrial dysfunction in aging provides critical insights into the molecular basis of fertility decline, particularly through its impact on endometrial receptivity. Full article

Interstitial lung disease (ILD) prevalence and survival are increasing due to improvement in scientific research together with clinical complications typical of advanced disease. Lung cancer (LC) is described as a possible event occurring in lung parenchyma in the context of fibrotic abnormalities that worsen patients’ prognosis. This growth of malignant cells on a fibrotic background has also been called scar-cinoma. For this reason, not only an early diagnosis but also personalized decisions on the best treatment approach should be considered for each patient in a multidisciplinary discussion, since in some cases chemotherapy or surgery could be detrimental for patients with pulmonary fibrosis. LC and lung fibrosis may share common pathogenetic mechanisms like an altered healing process in response to repeated tissue damage from environmental exposure in genetically susceptible individuals. Smoking history and air pollution together with mutations in telomere and surfactant protein genes lead to the production of cytokines and nitro derivatives in the microenvironment that facilitate the carcinomatous transformation during fibrogenesis. The evolution of LC therapy and the implementation of immunotherapy acting on targetable immune checkpoints have raised interest in evaluating ILD-LC actionable mutations. The main pathogenetic mechanisms, clinical presentations and treatment implications are presented in this review. Full article

Oxidative stress and inflammation influence immune response and epigenetic mechanisms in infectious diseases. In mild COVID-19, host-encoded miRNA profiles remain underexplored, although they reveal mechanistic insights into disease pathogenesis. This study evaluated ageing and oxidative stress biomarkers (telomere length (TL), TBARS, 8-OHdG, and circulating related-miRNA expression) in 75 mild cases and 30 non-COVID-19 controls. TL correlated with age (R = −0.384, p = 0.005) and was shorter in cases compared to controls (rTL 1.46 ± 0.51 vs. 0.99 ± 0.37; p < 0.001), being similar between saliva and blood samples (p = 0.917). miR-138-5p was upregulated in COVID-19 cases (p = 0.026) and correlated with 8-OHdG (R = 0.403, p = 0.05), which was increased in cases (p = 0.040); miR-210-3p was downregulated in infected individuals (p = 0.008), while miR-182-5p expression correlated with TBARS (R = 0.582, p = 0.018). miR-34a-5p and miR155-5p expression was not altered in mild COVID-19. These findings suggest early systemic cellular damage in mild COVID-19 and highlight miR-138-5p and miR-182-5p as potential early biomarkers of oxidative stress. Full article

The use of DNA as a scaffold for nanoclusters is particularly interesting due to its structural versatility and easy integration with aptamers. In their structure, aptamers often contain non-canonical forms of DNA, i.e., G-quadruplexes (GQs). Four-stranded GQs are used to construct nanomachines and biosensors for monitoring changes in the concentration of potassium ions. In the present study, we continue our work related to the synthesis of silver nanoclusters formed on a bifunctional DNA template. By attaching a cytosine-rich domain (C12) to a G-quadruplex-forming sequence—human telomeric (Tel22) or thrombin-binding aptamer (TBA)—we constructed bifunctional templates for fluorescent silver nanoclusters (C12) with the ability to detect potassium ions (GQs). The changing localization of the C12 domain from the 3′ to 5′ end of the oligonucleotide was a successful way to improve the fluorescence properties of the obtained fluorescent probes. The best performance as a probe for potassium ions was exhibited by C12Tel22-AgNCs, with an LOD of 0.68 mM in PBS. The introduction of the fluorescent cytosine analog tC leads to an LOD of 0.68 mM in PBS and 0.46 mM in Tris-acetate. Additionally, we performed AFM, TEM, DLS analysis, and cellular studies to further investigate the structural properties and behavior of the Tel22C12-AgNCs in biological contexts. Full article

Animal welfare is influenced by the cumulative life experiences of an individual. Among these, exposure to chronic stressors has a significant impact on both physical and mental health, contributing to premature aging—a process linked to telomere shortening. Conversely, positive experiences have been shown to mitigate, delay, and sometimes reverse telomere attrition. This suggests that telomere length could be a reliable indicator for assessing animal welfare. This study explored the association between telomere length and characteristics such as life history, environment, and health in domestic dogs. Buccal swabs collected DNA samples from 250 dogs, and telomere length was quantified via qPCR. Our findings revealed that environmental factors significantly influenced telomere length. Dogs housed in kennels or subjected to low physical activity levels exhibited shorter telomeres. Similarly, dogs living in groups of more than five dogs had shorter telomeres, and male dogs were found to have longer telomeres than females. Overall, these results highlight the importance of environmental conditions in influencing telomere length in dogs and the potential to use this biological indicator to evaluate animal welfare. Full article

The phosphatidylethanolamine-binding protein (PEBP) gene family is critical for regulating plant growth, development, and flowering. Sunflower (Helianthus annuus L.) is the fourth most important oilseed crop globally. However, the genomic structure and functional diversity of PEBP genes in sunflower remain unexplored. Leveraging the recently assembled telomere-to-telomere (T2T) sunflower genome, a genome-wide analysis of the HaPEBP family was carried out. A total of 12 PEBP genes were identified in sunflower and categorized into three subfamilies: TFL1-like, FT-like, and MFT-like. Phylogenetic and synteny analyses revealed that tandem duplication events have substantially contributed to the evolution and expansion of the HaPEBP gene family. Furthermore, the analysis of the promoter regions revealed 77 distinct cis-acting elements, including 35 related to light signaling and growth regulation, highlighting their potential involvement in the regulation of flowering and development in sunflower. Expression profile analysis using RNA-seq data across various tissues indicated that FT-like and TFL1-like HaPEBP genes may be the key regulators of flowering time and plant architecture in sunflower varieties. This study offers valuable insights into the structural, evolutional, and functional dynamics of the HaPEBP gene family and holds significant implications for sunflower breeding strategies aimed at optimizing flowering time and plant architecture traits. Full article

Neurocognitive disorders (NCD) are neurodegenerative diseases characterized by decline or loss of cognitive functions. Aging and the APOE genotype have been identified as major risk factors. Telomere length (TL) has been proposed as a biomarker of aging, with shorter TL associated with cognitive decline. This study investigated the relationship between TL and the APOE genotype in individuals with cognitive impairments (CIs). A total of 170 participants aged >55 years were included. Cognitive function was assessed using the MMSE and MoCA tests. Relative telomere quantification and APOE genotype were determined by real-time PCR. A significant association was observed between shorter TL and an increased risk of CI (p < 0.001). Although APOE ε4 is a known genetic risk factor, its association with CI was less clear in this study population, as a considerable proportion of ε4 carriers did not present cognitive impairment (p < 0.05). However, ε4 carriers with CI tended to have shorter TL than those with non-cognitive impairment (NCI-SMC). Furthermore, fewer years of education were strongly correlated with higher CI risk (p < 0.0001). Overall, individuals with both shorter telomeres and lower educational levels exhibited the highest risk of CI. APOE ε4 may contribute to telomere shortening. Full article

Background/Objectives: Telomerase plays a vital role in preserving telomere length, a key process in cancer development. Human telomerase reverse transcriptase (hTERT) is commonly expressed in various cancers, including melanoma. This study evaluated hTERT protein expression in melanomas compared to melanocytic nevi. Methods: In total, we examined 75 melanocytic lesions using TERT immunohistochemistry on paraffin-embedded tissues; 36 of them were thin melanomas (Breslow index ≤ 1 mm) and 39 melanocytic nevi. Results: The TERT expression differed with statistical significance between the two studied groups, melanomas and melanocytic nevi, in all three aspects examined: percentage of staining (p = 0.006), intensity of staining (p = 0.035), and localisation of staining (p = 0.012). Three quarters of the melanomas stained in over 50% of the cells at cytoplasmic level, 52.78% of the melanomas exhibited an intensity of 3+, and all melanomas were stained at the cytoplasmic level, except for the two negative cases. The values were lower in the melanocytic nevi group. Still, the diagnostic values were relatively low (sensitivity = 75%, specificity = 58.97%, PPV = 62.79%, NPV = 71.88%, and ACC = 66.67%). Conclusions: TERT immunohistochemistry differed between the two studied groups; however, the diagnostic utility is low in our study. Combining with other immunohistochemical antibodies would probably increase the diagnostic power. Full article

Piwi-interacting RNAs (piRNAs) play a crucial role in silencing transposable elements (TEs) in the germ cells of Metazoa by acting as sequence-specific guides. Originating from distinct genomic loci, called piRNA clusters, piRNA can trigger an epigenetic conversion of TE insertions into piRNA clusters by means of a paramutation-like process. However, the variability in piRNA clusters’ capacity to induce such conversions remains poorly understood. Here, we investigated two Drosophila virilis strains with differing capacities to produce piRNAs from the subtelomeric RhoGEF3 and Adar gene loci. We found that active piRNA generation correlates with high levels of the heterochromatic mark histone 3 lysine 9 trimethylation (H3K9me3) over genomic regions that give rise to piRNAs. Importantly, the maternal transmission of piRNAs drives their production in the progeny, even from homologous loci previously inactive in piRNA biogenesis. The RhoGEF3 locus, once epigenetically converted, maintained enhanced piRNA production in subsequent generations lacking the original allele carrying the active piRNA cluster. In contrast, piRNA expression from the converted Adar locus was lost in offspring lacking the inducer allele. The present findings suggest that the paramutation-like behavior of piRNA clusters may be influenced not only by piRNAs but also by structural features and the chromatin environment in the proximity to telomeres, providing new insights into the epigenetic regulation of the Drosophila genome. Full article

Telomere maintenance mechanisms (TMMs) play a critical role in cancer biology, particularly in lower-grade gliomas (LGGs), where telomere dynamics and pathway activity remain poorly understood. In this study, we analyzed TCGA-LGG and CGGA datasets, focusing on telomere length variations, pathway activity, and survival data across IDH subtypes. Additional validation was performed using the GEO COPD and GBM datasets, ensuring consistency in data processing and batch effect correction. Our analysis revealed significant differences in TEL pathway activation between Short- and Long-TL groups, emphasizing the central role of TERT in telomere maintenance. In contrast, ALT pathway activation displayed subtype-specific patterns, with IDH-wt tumors exhibiting the highest ALT activity, primarily driven by the RAD51 branch. Validation using CGGA data confirmed these findings, demonstrating consistent TEL and ALT pathway behaviors across datasets. Additionally, genetic subtype analysis revealed substantial telomere length variability associated with ATRX and IDH mutation status. Notably, IDHwt-ATRX WT tumors exhibited the shortest telomere length and the highest ALT pathway activity. These findings highlight distinct telomere regulatory dynamics across genetic subtypes of LGG and provide new insights into potential therapeutic strategies targeting telomere maintenance pathways. Full article