Comparison of Two Rabbit Models with Deficiency of Corneal Epithelium and Limbal Stem Cells Established by Different Methods

Abstract

Limbal stem cell defect model is an important animal model that provides a basis for the study of ocular surface diseases. The rabbit cornea is of moderate size and is widely used in such studies as an experimental animal model. At present, the main modeling methods are alkali burns, and corneal limbus girdling and corneal epithelium doctoring. Each method has its own characteristics. In this study, we observed rabbit models with severe ocular surface defect established by the two methods and changes after amniotic membrane transplantation. In the first, second, third, and fourth week after operation, the clinical manifestations, corneal transparency, and new vessels were observed according to the standard rating scale of ocular surface, compared between the two methods, and then statistically analyzed. In the fourth week after operation, the rabbits were sacrificed and their corneas and corneal limbus were extracted from sclera, embedded by optimum cutting temperature compound, frozen, and sliced for hematoxylin and eosin staining and pathological examination. There were two groups in this study. Group 1 (alkali burns) had more severe complications, such as, conjunctiva, nubecula, new vessel hyperplasia, and so on, compared to group 2 (corneal limbus girdling and corneal epithelium doctoring). In addition, there were striking differences in corneal transparency and new vessels between the two groups (p < 0.05). Corneal transparency in group 1 was lower than in group 2. New vessels in group 1 were less in the first 2 weeks, but obviously increased compared to group 2 in the subsequent weeks. Alkaline burn could be used to study new vessel hyperplasia, while corneal limbus girdling and corneal epithelium doctoring are more suitable for studying stem cell transdifferentiation, interactive roles of stem cells and microenvironment, and so on.

Culture surface protein coatings affect the barrier properties and calcium signalling of hESC-RPE

“…Further functional analysis by phagocytosis assay suggested improved functionality in cells cultured on more complex protein coatings containing 1x or 10x Nid-1 in terms of the number of internalised POS particles and increased cell population homogeneity. In addition to phagocytosis, functionality of especially the ATP-mediated purinergic pathway has been considered an important criterion when assessing the quality of hiPSC-RPE for clinical applications due to the important role of ATP in the regulation of RPE physiology 5,26,52 . More generally, Ca 2+ signalling is an important regulator of numerous cell functions, controlled by the temporal and spatial distribution of [Ca 2+ ] i…”

Effect of air-lifting on the stemness, junctional protein formation, and cytokeratin expression of in vitro cultivated limbal epithelial cell sheets

“…Different cell culture techniques have been proposed with various successes. [ 19 20 21 ] During in vitro culturing, whether cell sheet products need to receive air-lifting is an important issue that has not been well-evaluated before. It is well-known that air-lifting can improve cellular stratification and improve cellular differentiation with the formation of epithelial tight junctions in vitro .…”

Recent Advances in Experimental Burn Models

“…Several animal models have been established to study corneal burn injuries. These models generally use a NaOH solution (1 N), which is directly applied to the center of the corneal surface in animals for 15-60 s [53][54][55][56]60,61,63]. Similar to the process in humans, the process of corneal alkali burn healing in animal models involves immediate local inflammation followed by fibrosis and neovascularization.…”