RESUMEN

Advances in modern healthcare in developed countries make it possible to extend the human lifespan, which is why maintaining active longevity is becoming increasingly important. After the sirtuin (SIRT) protein family was discovered, it started to be considered as a significant regulator of the physiological processes associated with aging. SIRT has deacetylase, deacylase, and ADP-ribosyltransferase activity and modifies a variety of protein substrates, including chromatin components and regulatory proteins. This multifactorial regulatory system affects many processes: cellular metabolism, mitochondrial functions, epigenetic regulation, DNA repair and more. As is expected, the activity of sirtuin proteins affects the manifestation of classic signs of aging in the body, such as cellular senescence, metabolic disorders, mitochondrial dysfunction, genomic instability, and the disruption of epigenetic regulation. Changes in the SIRT activity in human cells can also be considered a marker of aging and are involved in the genesis of various age-dependent disorders. Additionally, experimental data obtained in animal models, as well as data from population genomic studies, suggest a SIRT effect on life expectancy. At the same time, the diversity of sirtuin functions and biochemical substrates makes it extremely complicated to identify cause-and-effect relationships and the direct role of SIRT in controlling the functional state of the body. However, the SIRT influence on the epigenetic regulation of gene expression during the aging process and the development of disorders is one of the most important aspects of maintaining the homeostasis of organs and tissues. The presented review centers on the diversity of SIRT in humans and model animals. In addition to a brief description of the main SIRT enzymatic and biological activity, the review discusses its role in the epigenetic regulation of chromatin structure, including the context of the development of genome instability associated with aging. Studies on the functional connection between SIRT and longevity, as well as its effect on pathological processes associated with aging, such as chronic inflammation, fibrosis, and neuroinflammation, have been critically analyzed.

RESUMEN

CP190 protein is one of the key components of Drosophila insulator complexes, and its study is important for understanding the mechanisms of gene regulation during cell differentiation. However, Cp190 mutants die before reaching adulthood, which significantly complicates the study of its functions in imago. To overcome this problem and to investigate the regulatory effects of CP190 in adult tissues development, we have designed a conditional rescue system for Cp190 mutants. Using Cre/loxP-mediated recombination, the rescue construct containing Cp190 coding sequence is effectively eliminated specifically in spermatocytes, allowing us to study the effect of the mutation in male germ cells. Using high-throughput transcriptome analysis we determined the function of CP190 on gene expression in germline cells. Cp190 mutation was found to have opposite effects on tissue-specific genes, which expression is repressed by CP190, and housekeeping genes, that require CP190 for activation. Mutation of Cp190 also promoted expression of a set of spermatocyte differentiation genes that are regulated by tMAC transcriptional complex. Our results indicate that the main function of CP190 in the process of spermatogenesis is the coordination of interactions between differentiation genes and their specific transcriptional activators.

Asunto(s)

Proteínas de Drosophila , Drosophila melanogaster , Animales , Masculino , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Espermatocitos/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Proteínas Nucleares/genética , Proteínas Asociadas a Microtúbulos/genética , Drosophila/genética , Diferenciación Celular/genética , Elementos Aisladores

RESUMEN

The correct deployment of genetic programs for development and differentiation relies on finely coordinated regulation of specific gene sets. Genomic regulatory elements play an exceptional role in this process. There are few types of gene regulatory elements, including promoters, enhancers, insulators and silencers. Alterations of gene regulatory elements may cause various pathologies, including cancer, congenital disorders and autoimmune diseases. The development of high-throughput genomic assays has made it possible to significantly accelerate the accumulation of information about the characteristic epigenetic properties of regulatory elements. In combination with high-throughput studies focused on the genome-wide distribution of epigenetic marks, regulatory proteins and the spatial structure of chromatin, this significantly expands the understanding of the principles of epigenetic regulation of genes and allows potential regulatory elements to be searched for in silico. However, common experimental approaches used to study the local characteristics of chromatin have a number of technical limitations that may reduce the reliability of computational identification of genomic regulatory sequences. Taking into account the variability of the functions of epigenetic determinants and complex multicomponent regulation of genomic elements activity, their functional verification is often required. A plethora of methods have been developed to study the functional role of regulatory elements on the genome scale. Common experimental approaches for in silico identification of regulatory elements and their inherent technical limitations will be described. The present review is focused on original high-throughput methods of enhancer activity reporter analysis that are currently used to validate predicted regulatory elements and to perform de novo searches. The methods described allow assessing the functional role of the nucleotide sequence of a regulatory element, to determine its exact boundaries and to assess the influence of the local state of chromatin on the activity of enhancers and gene expression. These approaches have contributed substantially to the understanding of the fundamental principles of gene regulation.