Gravity sensing by cells: mechanisms and theoretical grounds

Abstract

Spaceflight technologies have disclosed amazing opportunities to outreach human knowledge and control over the natural world. However, the actual experience of microgravity has become a relevant threat that significantly limits the extent of man permanence in space. Since then, gravity effects on living organisms became a critical field of investigation. Gravity has been proven to affect a wide array of biological functions, interacting at different levels of complexity, from molecules to cells, tissue and the organisms as a whole. However, it is still a matter of investigation if gravity induces direct or indirect effects on cells. The non-equilibrium theory has been proven to explain how biological dissipative structures, like the cytoskeleton, may be sensitive enough to sense gravity change, then transferring the mechano-signal into biochemical pathways. Within that framework, gravity represents an 'inescapable' constraint that obliges living beings to adopt only a few configurations among many others. By removing the gravitational field, living structures will be free to recover more degrees of freedom, thus acquiring new phenotypes and new properties. Discoveries on that field are thought to advance our knowledge, providing amazing insights into the biological mechanism underlying physiology as well as many relevant diseases

Identifications of novel mechanisms in breast cancer cells involving duct-like multicellular spheroid formation after exposure to the Random Positioning Machine

“…Real and simulated microgravity can directly or indirectly influence a cell2746. Human cells are able to react to environmental changes.…”

“…Gravitation might influence some general properties of the cells and thus acting “directly” as an organizing field parameter46. According to the non-equilibrium theory49 murine osteoblasts and breast cancer cells underwent a transition after a bifurcation point to new phenotypic configurations1830.…”

Laser interferometric investigation of solute transport through membrane-concentration boundary layer system

“…In these cells, the uptake rate of oxygen and nutrients is changed and therefore the cell metabolism is significantly affected. The cells in a microgravity field show major changes, involving metabolism, cytoskeleton, membrane structure, gene regulation, shape, and many other biological properties [22–27]. …”

The Unconventionality of Nature: Biology, from Noise to Functional Randomness

“…In this perspective, canalization by constraints may be another suitable concept for the relation between biological dynamics and their contour or internal conditions. Some recent experiences in microgravity (Bizzarri et al 2014 ) show that unicellular eukariota develop wild cytoskeleta when they reproduce in geo-stationary satellites. The idea is that gravity constrains development: typically, it canalizes cytoskeletal growth towards relatively flat structures as well as it selects negatively shapes that are unsuitable for subsistance or movement.…”