What do you do if you’re a cell and your neighbour is dying because of exposure to pollutants? You eat it before it becomes toxic! A new study published in the Journal of Biochemistry and Molecular Biology shows that a PAC-MAN-style mechanism occurs in the eye lens to get rid of dying cells.
The eye lens, which is devoid of a blood supply, has undergone a variety of evolutions to shield itself from environmental damage that is linked with cell and tissue death, specially that it is constantly exposed to UV light. The researchers aimed at finding the mechanism behind these processes.
It was discovered that cells in the eye lens can sense if others in their proximity are dying because of the influence of environmental stressors such as pollutants, UV light, or smoke. Upon detecting such dying cells, they ingest them to prevent them from becoming toxic. Furthermore, the molecules that are essential for this process were also discovered by the scientists.
They found that the intact eye lens can remove apoptopic lens cell debris. The latter is known to be harmful to cells of the epithelium of different tissues, and its accumulation has been associated with autoimmune diseases, inflammation, ageing, and degenerative conditions, as explained by the author of the paper, Marc Kantorow from Florida Atlantic University (FAU). Therefore, finding the ways in which cells protect themselves from apoptosis-inducing insults will possibly help to develop treatment for these diseases.
The scientists observed the “eating” mechanism after they modified the eye lens cells to fluoresce either red or green. They made artificial dead green cells which ate the red ones, a process marked by the transition of green colour to yellow. By using antibodies, they also identified the molecules used by the cells to eat each other.
These results show that a tissue can be kept alive in an alternative way, other than having specialised immune cells ingest the dead cells.
Kantorow hopes that their work can pave the way for techniques to treat cataracts instead of using surgical methods, as is the case nowadays. Furthermore, such mechanisms are not restricted to the eyes, and might thus provide relevant information pertaining to other complex tissues and diseases.