[Problems of gravitational physiology of cell]

The article is an overview of the results of experimental studies of cell gravitosensitivity per se. The first uncontrolled experiments on simple bio-models in short-term space flights gave conflicting data and yet implied no lethal or irreversible consequences of exposure in microgravity. The application of special devices and a partial environmental control in the absence of adequate analytical procedures of assessing the cell functional status led some investigators to the supposition that cell cultures are insensitive to gravity. Recent advancement of molecular and cell technologies provided the way of revealing numerous and often reversible morphofunctional changes in cells during space flight and laboratory simulation of the zero-g effects These are remodeling of cytoskeleton elements, alteration of gene expression, and mosaic rearrangement of intracellular regulation systems. Bioengineering and stem cell technologies gave another impetus to these investigations. Better understanding of intercellular interactions, role of cytokines and creation of 3D structures in the absence of the force of gravity made possible the evidence-based substantiation of differentiation lag as well as dependence of these changes on cell mechanic responses, and other phenomena. Academician O.G.Gazenko, director of the Institute for Biomedical Problems over many years, was at the head of the USSR biosat research programme demonstrating his devotion to and awareness of the significance of fundamental knowledge about the influence of gravity on every level of living system organization.