Cell models in keratoconus nature research

Relevance It is known that a violation of the microelement environment occurs in the development of some corneal diseases, including keratoconus (KC). In this disease, the corneal tissue is depleted of chalcophile metal ions (iron, copper and zinc), which ultimately results in a violation of its biomechanical properties. Despite the active development of precision methods for studying the cornea [1], the study of the etiopathogenesis of KC is still significantly complicated in patients in vivo, and modeling is difficult to reproduce in animals [2]. Modern cellular technologies make it possible to study the etiology and pathogenesis of eye diseases, as well as to develop new methods of therapy [3-5]. Thus, the development of cellular models of KC based on human keratocytes makes it possible to study the morphological and biomechanical changes in the cornea characteristic of this disease by assessing the effect of chalcophile elements on the properties of connective tissue in vitro. Objective To obtain tissue-engineered constructs from corneal fibrocytes under conditions of growth media depletion of chalcophile ions, and to study their morphological and biomechanical properties. Material and methods Cell cultures obtained from keratocytes of healthy donors were grown in the form of three-dimensional tissue-engineered constructs consisting of corneal fibrocytes and the intercellular substance produced by them. Corneal fibrocytes were grown in the form of cell sheets on standard and chalcophile ion-depleted nutrient media, thus obtaining models of the corneal stroma in the “norm” and in CC. Depletion of growth media with chalcophile ions was carried out using an original technique by decationization of fetal bovine serum with ion-exchange resins. The obtained cell models were studied using light and electron microscopy, immunohistochemical analysis, biomechanical bending tests, and nanoindentation using an atomic force microscope. Results Tissue-engineered constructs modeling the "keratoconus" corneal stroma had a number of significant differences compared to the "healthy" cornea models. Thus, in an iron-free medium, the culture died on the 7th-10th day. Under copper depletion conditions, cell samples were lost after 4 weeks of cultivation due to disruption of the adhesion of cell layers to the carrier. Cellular models of corneal corneal cells obtained under zinc-depleted conditions during the 2- and 4-week cultivation period, as well as those obtained under copper-depleted conditions during the 2-week cultivation period, had a number of fundamental differences in morphological, immunohistochemical and biomechanical properties in comparison with tissue-engineered constructs simulating “healthy” corneal stroma during the same cultivation periods. Conclusion The obtained results allow us to draw reasonable conclusions about the essential role of chalcophile metal ions in the metabolism and functioning of connective tissue structures. Such conclusions are consistent with the modern concept of corneal corneal corneal etiopathogenesis, according to which the disruption of the biomechanical properties of the cornea in this disease is a consequence of mineral dysmetabolism. Keywords: zinc; copper; chalcophile elements; biomechanics