I am conducting my research on cornea and I read about endothelial cells. It's very interesting to know that corneal cells are derived from neural crest. I have developed little bit about it. But I want to know the logic. Thanks
Why do the corneal endothelial cells do not have an ability to proliferate?
Some thinks it´s important to know.
Human embryo, 7 weeks old.
Human Corneal endothelial cells and keratocytes originate from neural crest cells and then differentiate into mesenchymal cells. Human embryo, 7.5 weeks old: Corneal endothelium consists of a double layer of cuboidal or flat cells. These cells starts to form Descemet membrane.
Human fetus, 5 months old
Corneal endothelium appears as a monolayer at the 18th week. The decrease in cellularity of the endothelium is more rapid during the prenatal months than during the first 2 postnatal years. The diameter of the cornea increase from 4.2 to 9.3mm, from 16 weeks gestational age to term. During this time de endothelial surface increases from 14 to 68 mm². This rapid enlargment provides much more space to be covered by the endothelial cells.The decrese in cellularity and the increase in the surface of the corneal endotelium to be covered cause changes in the packing, size, thickness and shape of the endothelial cells.
Barishak,YR. Embriology of the Eye and Its Adnexa. 2nd Ed. 2001
After this phase the cell cycle remains blocked, some believe that due to factors inherent to the aqueous humor, but there is still no clear proof of the real reason.
It is known that its mitosis after birth is rare. The amount of your cells gradually decreases during life. This major decrease occurs in the first 5 to 6 years of life due to corneal growth in diameter. I suggest you study well the cycle of cell division and expand literature review included the article below.
Okumura N, Inoue R, Okazaki Y, Nakano S, Nakagawa H, Kinoshita S, Koizumi N. Effect of the Rho Kinase Inhibitor Y-27632 on Corneal Endothelial Wound Healing. Invest Ophthalmol Vis Sci. 2015 Sep;56(10):6067-74.
Abib FC1, Barreto Junior J. Behavior of corneal endothelial density over a lifetime. J Cataract Refract Surg. 2001 Oct;27(10):1574-8.
It is rare to prove clinically significant mitosis. It is believed that they may be related to herpex virus infiltration. In my professional and research experience I have 2 or 3 well documented cases. If you study endothelium by means of specular microscopy, follow the articles below.
Bernard E. McCarey, Henry F. Edelhauser, Michael J. Lynn. Review of Corneal Endothelial Specular Microscopy for FDA Clinical Trials of Refractive Procedures, Surgical Devices and New Intraocular Drugs and Solutions. Cornea. 2008 Jan; 27(1): 1–16.
Abib FC, Holzchuh R, Schaefer A, Godois R. The Endothelial Sample Size Analysis in