International scientific-online conference NUCLEOLAR MIGRATION IN HEPATOCYTES OF ELDERLY INDIVIDUALS: A MORPHOLOGICAL STUDY Isayeva Nilufar Zubidullayevna

Аннотация

This study presents the results of a morphological examination of the liver in healthy elderly individuals to investigate the process of nucleolar granular component migration from the nucleus to the cytoplasm of hepatocytes. It was established that this process is analogous to that observed in animals, with no fundamental differences between species. The analysis revealed age-related morphological changes, such as lipofuscin accumulation, dystrophic processes, and nuclear polymorphism. Special attention was given to the characteristics of migrating nucleoli, including their shape, size, and potential mechanisms of exit from the nucleus into the cytoplasm. The obtained data confirm the possibility of nucleolar migration in humans and its potential role in cellular processes. Keywords: hepatocytes, nucleolus, migration, morphology, age-related changes, lipofuscin, dystrophy, human liver, cellular processes, nuclear polymorphism. Introduction. The liver is one of the key organs of the human body, performing numerous vital functions, including detoxification, metabolism, protein synthesis, and energy regulation. Hepatocytes, which constitute the primary parenchymal cells of the liver, exhibit high functional activity and morphological plasticity. One of the less studied processes occurring in hepatocyte nuclei is the migration of the nucleolar granular component from the nucleus to the cytoplasm. Previously, nucleoli were considered exclusively intracellular structures involved in ribosome biogenesis and transcription regulation. However, studies conducted on animal models (rabbits and white rats) have demonstrated that nucleoli can exit the nucleus into the cytoplasm, raising the question of whether a similar mechanism exists in humans [Yermolaev, 2004]. Age-related liver changes include lipofuscin accumulation, dystrophic processes, and structural reorganization of hepatic plates, which may influence intracellular transport mechanisms. This study examines the possibility of nucleolar migration in healthy elderly individuals, identifies the morphological features of this process, and compares it with similar phenomena observed in 27 THEORETICAL ASPECTS IN THE FORMATION OF PEDAGOGICAL SCIENCES International scientific-online conference animals. The conducted research aims to provide a deeper understanding of the mechanisms of intracellular nucleolar transport and its potential role in human cell physiology. Objective and Methods. The objective of this study is to investigate the morphological aspects of nucleolar granular component migration from the nucleus to the cytoplasm in human hepatocytes and to determine the features of this process in healthy elderly individuals. Special attention was given to age- related structural changes in the liver and possible mechanisms of nucleolar exit from the nucleus. To achieve this objective, the following research methods were employed: General morphological analysis of liver structures using standard histological staining techniques (hematoxylin-eosin). Light microscopy to examine the ultrastructural changes in hepatocytes and identify morphological signs of nucleolar migration. The study was conducted using a DN-300 M light microscope with a digital photo attachment at ×40 and ×100 magnification. Histological analysis of autopsy liver samples from 22 patients (12 males and 10 females) aged 60 to 83 years, who had died from causes unrelated to liver pathology. Comparative analysis to correlate the obtained data with findings from studies on animal models (rabbits, white rats) to identify possible similarities and differences in the mechanism of nucleolar migration. These methods enabled a detailed analysis of morphological changes in hepatocytes and confirmed the possibility of nucleolar migration in humans. Results. The morphological study of the liver in healthy elderly individuals revealed the migration of nucleoli from the nucleus to the cytoplasm of hepatocytes. This process was found to be analogous to that observed in animals, without fundamental species differences. Microscopic examination of liver structure demonstrated pronounced nuclear polymorphism in hepatocytes. Most cells contained small to medium- sized nuclei, but occasional large and giant nuclei were observed. Migration of nucleoli was most frequently observed in large nuclei, where nucleoli moved from the nuclear center toward the periphery, protruded through the nuclear envelope, and exited into the cytoplasm. Age-related liver changes included lipofuscin accumulation in hepatocyte cytoplasm, particularly around central veins, as well as various degrees of dystrophic processes. In most cases, fatty, granular, and vacuolar dystrophy were observed, either in focal or diffuse forms. 28 THEORETICAL ASPECTS IN THE FORMATION OF PEDAGOGICAL SCIENCES International scientific-online conference A special focus was placed on structural changes in nucleoli. The study found that primarily large nucleoli underwe