If you want to see want to see clearly what is going on outside while you are inside your home or office, the windows need to be clean. It’s the same thing with your eyes. Specifically, the lens has to be free of obstruction.
Yet unlike most cells, the cells that make up the lens of the eye degrade their nuclei and other cell parts. While this sounds bad, if the cell parts were left as is, cataracts would form at an earlier age.
Scientists didn’t understand how the cells got rid of obstructions without getting in the way of the development of the eye lens. Recently, however, a researcher at the University of Delaware showed that the RNA binding protein, CELF1, is a part of this process.
Salil A. Lachke, PhD and his team demonstrated how this occurs in three different animals, mice, frogs, and zebrafish. His lab showed that CELF1 “rewires” parts normally involved in cell division in order to control cell differentiation and specialization while the lens is developing. In fact, this protein is essential to tearing down the nucleus’ membrane and assimilating the cell’s DNA, so that vision is not obstructed. In other words, there is destruction as well as construction, in the eye.
Still, not everything is destructed. In most cases of cell death, the nuclei as well as the other parts of the cell are destroyed. When it comes to lens cells, the nucleus is destroyed but the rest of the cell is saved. It is analogous to removing the façade and all the internals of a building but the scaffolding is left intact.
Why leave the scaffolding without the nucleus intact? Having a cell without the nucleus allows it to be used for storage – specifically, storage of crystallin proteins that refract light to the retina. The bad part about this is that over time, ultraviolet light destroys these proteins, they clump together, and eventually they form cataracts.
While there is no way to stop cataracts from forming, this research suggests that there might be a way to identify the cause of the crystallin clumping. Treatments can then be developed to stop the clumping. Lachke’s lab has already put together genetic profiles of the lens tissue of mice during different stages of development. The lab also created a free bioinformatic tool that other researchers can use called iSyTE (integrated Systems Tool for Eye gene discovery) and it can be found here: https://research.bioinformatics.udel.edu/iSyTE/ppi/. Other researchers can use the information in this website to analyze the genes in the lens and learn how to delay the onset of cataracts.
Just as there is always destruction and construction in cities and towns, the same can be said about the eye lens. More and more is being learned about the reasons for this destruction and construction. Hopefully this knowledge will lead to better, more proactive treatments for cataracts in the future.
Sources:
http://www.udel.edu/udaily/2018/may/biologist-salil-lachke-eye-lens-gene-discovery/
https://directorsblog.nih.gov/2018/05/17/snapshots-of-life-lens-crafting/