Physico-chemical and biological considerations for membrane wound evolution and repair in animal cells.

Membrane damage is a daily threat to the life of a cell, especially cells from muscles, gut, epidermis and vasculature, tissues that are particularly subjected to mechanical stress. Damages can come from different sources and give rise to different holes in terms of size and nature. For example, while some holes are simply scratches in the lipid bilayer, others are delimited by pore forming proteins. It is thus expectable that these wounds will not evolve similarly in a cellular context, and that repair mechanisms will differ to a certain extent. It would therefore be misleading to fully generalize cell membrane damage and repair, and consider it as one universal phenomenon. Indeed, damage has been observed in cells ranging from the rather small mammalian cells (∼30µm) to the very big Urchin egg (∼100µm). Moreover, the wounds observed or artificially induced in eukaryotic cells range from some nanometers to several micrometers, and can be delimited by particular molecules as mentioned before. This chapter aims at reviewing the different physico-chemical and biological parameters that can influence wound evolution in cells and to conciliate the different repair mechanisms that have been described by evaluating them in their cellular and wound type context.