Acute telomerase components depletion triggers oxidative stress as an early event previous to telomeric shortening
Loss of function of dyskerin (DKC1), NOP10 and TIN2 are responsible for different inheritance patterns of Dyskeratosis congenita (DC; ORPHA1775). They are key components of telomerase (DKC1 and NOP10) and shelterin (TIN2), and play an important role in telomere homeostasis. They participate in several fundamental cellular processes by contributing to Dyskeratosis congenita through mechanisms that are not fully understood. Presence of oxidative stress was postulated to result from telomerase ablation. However, the resulting disturbed redox status can promote telomere attrition by generating a vicious circle, which promotes cellular senescence. This fact prompted us to study if acute loss of …
Role of glutathione in the regulation of epigenetic mechanisms in disease
Epigenetics is a rapidly growing field that studies gene expression modifications not involving changes in the DNA sequence. Histone H3, one of the basic proteins in the nucleosomes that make up chromatin, is S-glutathionylated in mammalian cells and tissues, making Gamma-L-glutamyl-L-cysteinylglycine, glutathione (GSH), a physiological antioxidant and second messenger in cells, a new post-translational modifier of the histone code that alters the structure of the nucleosome. However, the role of GSH in the epigenetic mechanisms likely goes beyond a mere structural function. Evidence supports the hypothesis that there is a link between GSH metabolism and the control of epigenetic mechanisms…
From genetics to epigenetics to unravel the etiology of adolescent idiopathic scoliosis.
Scoliosis is defined as the three-dimensional (3D) structural deformity of the spine with a radiological lateral Cobb angle (a measure of spinal curvature) of ≥10° that can be caused by congenital, developmental or degenerative problems. However, those cases whose etiology is still unknown, and affect healthy children and adolescents during growth, are the commonest form of spinal deformity, known as adolescent idiopathic scoliosis (AIS). In AIS management, early diagnosis and the accurate prediction of curve progression are most important because they can decrease negative long-term effects of AIS treatment, such as unnecessary bracing, frequent exposure to radiation, as well as saving the…
Oxidative stress and antioxidant response in fibroblasts from Werner and Atypical Werner Syndromes
Werner Syndrome (WS, ICD-10 E34.8, ORPHA902) and Atypical Werner Syndrome (AWS, ICD-10 E34.8, ORPHA79474) are very rare inherited syndromes characterized by premature aging. While approximately 90% of WS individuals have any of a range of mutations in theWRN gene, there exists a clinical subgroup in which the mutation occurs in the LMNA/C gene in heterozygosity. Although both syndromes exhibit an age-related pleiotropic phenotype, AWS manifests the onset of the disease during childhood, while major symptoms in WS appear between the ages of 20 and 30. To study the molecular mechanisms of progeroid diseases provides a useful insight into the normal aging process. Main changes found were the d…
Acute depletion of telomerase components DKC1 and NOP10 induces oxidative stress and disrupts ribosomal biogenesis via NPM1 and activation of the P53 pathway.
Mutations in DKC1, NOP10, and TINF2 genes, coding for proteins in telomerase and shelterin complexes, are responsible for diverse diseases known as telomeropathies and ribosomopathies, including dyskeratosis congenita (DC, ORPHA 1775). These genes contribute to the DC phenotype through mechanisms that are not completely understood. We previously demonstrated in models of DC that oxidative stress is an early and independent event that occurs prior to telomere shortening. To clarify the mechanisms that induce oxidative stress, we silenced genes DKC1, NOP10, and TINF2 with siRNA technology. With RNA array hybridisation, we found several altered pathways for each siRNA model. Afterwards, we ide…
Epigenetics in spine curvature disorders
Abstract Scoliosis is a three-dimensional (3D) structural deformity of the spine with a radiological lateral Cobb angle of ≥ 10°. Several classification systems exist, dividing different types regarding the age of onset or the type of etiology. The minority of cases are secondary to congenital, syndromic of neuromosucular diseases. Most of the cases are classified “idiopathic” due to unknown etiology. These were formally divided by the age of onset into “Infantile Idiopathic Scoliosis” (0–3 years), “Juvenile Idiopathic Scoliosis” (JIS—4–10 years), and “Adolescent Idiopathic Scoliosis” (AIS → 10 years). Since the initiative of the Scoliosis Research Society in 2014 all kind of scoliosis with…
Harmonization of QSAR Best Practices and Molecular Docking Provides an Efficient Virtual Screening Tool for Discovering New G-Quadruplex Ligands
Telomeres and telomerase are key players in tumorogenesis. Among the various strategies proposed for telomerase inhibition or telomere uncapping, the stabilization of telomeric G-quadruplex (G4) structures is a very promising one. Additionally, G4 stabilizing ligands also act over tumors mediated by the alternative elongation of telomeres. Accordingly, the discovery of novel compounds able to act on telomeres and/or inhibit the telomerase enzyme by stabilizing DNA telomeric G4 structures as well as the development of approaches efficiently prioritizing such compounds constitute active areas of research in computational medicinal chemistry and anticancer drug discovery. In this direction, we…
Epigenetic biomarkers for disease diagnosis
Abstract Epigenetic dysregulation plays an important role in the initiation and progression of human diseases; therefore, because of the dynamic nature of this orchestrated regulation of epigenetic marks and epigenetic mechanisms, it is possible to use these marks as biomarkers. In this context, an epigenetic biomarker is “any epigenetic mark or altered epigenetic mechanism” which generally serves to evaluate health or disease status, progression or treatment response and is particularly stable and reproducible during sample processing. Advances in precision medicine, with better diagnostic and treatment strategies are the hope to improve the management of diseases, comorbidities, and morta…