Hyaluronan and Induction of Cellular Cycles for Differentiated Cells

4 Hyaluronan and Induction of Cellular Cycles for Differentiated Cells 

The integrity of a cell is based not on the strength of the materials it is built from, but on the coordination of the processes of breakdown and synthesis [89-94]. Cells are capable not only of continuous self-renewal but also of self-reproduction. The majority of the populations of the differentiated cells in vertebrates are subjected to self-reproduction. When cells are worn out in biological terms and perish, they are replaced by new cells formed as a result of mitotic division of the differentiated cells. The differentiated state 

At the same time, as was mentioned [106], some hyaluronan oligosaccharides can participate in the gene switching at the early stages of the cellular cycle initiation, that is, can fulfil regulatory functions. Thus, in all likelihood, nuclear HA participates in the structural 

This turnover includes the stages of the hyaluronan synthase-2 gene activation for the transcriptions of the enzyme s mRNA, enzyme incorporation into cytoplasmic membrane followed by the synthesis and direct translocation of HA into intercellular space, further transport from the intercellular space into the nucleus and fulfilment of the functions required for reconstruction, motion and organization of chromosomes in the nucleus. There is not yet sufficient experimental data to surely confirm this common picture, but from the data available it is possible to suggest such a description. This conclusion provides directions for further experimental research. 

There are certain cells that, after being formed in a necessary quantity in embryo, remain unchanged in the course of the entire organism s hfe. Such cells never divide and cannot be replaced in the case of their loss. These are called permanently differentiated cells. These are almost all varieties of nerve cells, heart muscle cells, photoreceptors and cells of the crystalline lens of an eye in mammals. The macromolecules of proteins and hyaluronan are renewable in the permanent cells. Reliable evidence indicating that HA participates in the maintenance of the permanently differentiated cells is not yet available. 

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