Mechanisms of the keeping and change of forms and sizes of the cell nuclei (review)

The size and shape of the cell nucleus are the frequently used parameters in the studies of Russian and foreign-states authors, not only as necessary for calculating the nuclear-cytoplasmic ratio of a cell in ontogenesis, differentiation, and pathological processes, but also having values as such. However, in discussions, two extreme points of view are expressed on the value of information about the shape and, especially, about the size of the nucleus. According to the first point of view, the morphometry of the size and shape of the cell nucleus without measuring the cytoplasm with the subsequent calculation of the nuclear-cytoplasmic ratio does not make any sense, and the data obtained do not carry significant information. Proponents of the second point of view consider the cell nucleus as a labile and significant indicator of the morphological and functional state of the cell, the size and shape of which change during normal aging, pathological conditions, proliferation, gene expression, and protein synthesis. In this regard, a meta-analysis of modern scientific literature devoted to the study of the mechanisms of maintaining and changing the size and shape of the cell nucleus was carried out. The data obtained were subjected to an analytical study in order to formulate and explain the structures, factors and mechanisms of maintenance, changes in the size, shape of the cell nucleus. Based on the analysis of data from Russian and foreign-states sources, it can be confidently stated that the amount of DNA in the nucleus is not the only factor that determines its size and shape, but also the structure and modification of chromatin can affect nuclear morphology. It can be considered proven that the leading structures of the cell that determine the size and shape of the cell nucleus are the cytoskeleton, the complex of nuclear pores, the nuclear lamina, the endoplasmic reticulum, and the factors are nuclear-cytoplasmic exchange and osmolarity. Further study of the structures and factors affecting the size and shape of the nucleus, establishing the relationship between its morphology and processes occurring at the tissue and cellular levels, promises to provide new approaches to the diagnosis, prevention and treatment of a number of diseases.