in extreme periphery of endothelium on human corneas with a short postmortem time and that a very slow and continuous centripetal cell migration might exist to partially compensate the physiological cell loss in vivo. Nevertheless, this mechanism cannot immediately compensate neither acute nor chronic important CEC losses which are replaced by enlargement and migration of neighboring cells resulting in shape modification and increase of cell size. In physiologic conditions the insufficient proliferative capacity leads to a gradual ECD ON-014185 decrease of 0.3�C0.6% per year. This decrease can be accelerated as a result of accidental trauma, certain systemic diseases like diabetes, treatment for glaucoma or endothelial dystrophies. When ECD falls below a critical threshold, the barrier and pump���� functions of the endothelium are compromised and this results in the formation of a corneal oedema and loss of visual acuity. The conventional treatment for such severe disorder is corneal transplantation, including penetrating keratoplasty and endothelial lamellar graft. Human corneas harvesting, evaluation, preservation and distribution are under the responsibility of eye banks, which stores corneal tissue either for short term at 2�C6uC or for long term at 30�C32uC in culture medium. Unfortunately, there is a worldwide shortage of donor corneas available for transplantation. Several approaches have been evaluated to overcome this lack of tissues. Improvement of surgical procedures allows optimizing the use of corneal graft, especially by lamellar technique, according to the principle of split cornea transplantation for two recipients. In order to extend the EC viability of organ-culture cornea, an anti-apoptotic gene therapy was also assessed. Experiments demonstrated that expression of anti-apoptotic proteins Bcl-xL or p35 allowed limiting the cell loss and increasing the number of available donor��s corneas.. During the last decades, in vitro culture technics of human corneal endothelial cells have greatly improved. These cells can be MEDChem Express Vps34-IN-1 isolated and expanded in culture either as a monolayer or as sphere-forming colonies and a number of studies showed the possibility to transplant them as a cellular sheet with or without a carrier or by injecting them directly
