Molecular Genetic Aspects of the Optimizing Effect of Oxytocin on the Reparative Processes of Rabbit Eye Corneal Epithelial and Stromal Structures

The aim of study was to determine the regenerative effect of oxytocin on the expression of PAX6, MKI67, TAB3 genes, respectively, during experimental corneal erosion.

Material and methods. The study involved experimental animals divided into three groups (6 rabbits total). Groups 1 and 2 were simulated erosion of the cornea 8mm in diameter. Animals of group 3 – control – were without damage to the cornea. Group 1 consisting of 2 rabbits was instilled antibiotic cypromed 0.3% in the conjunctival sac; group 2 consisting of 2 rabbits was instilled oxytocin 5ME and cypromed 0.3%. Samples of the anterior epithelium and stroma were taken in all animals on the 4th and 8th day of the experiment, histological preparations were made. mRNA, the relative content of which was evaluated by electrophoresis, was isolated from the samples. cDNA was obtained using reverse transcription. The expression of the studied genes was evaluated based on the real-time PCR.

Results. The expression of the target genes PAX6, MKI67, TAB3 was normalized relative to the “house-hold” genes HPRT and RPL5 using REST program. Oxytocin stimulated increased expression of the MKI67 gene in the stroma (2.3 times on the 4th day), followed by normalization on the 8th day. PAX6 and TAB3 genes, in contrast, decreased their expression under the effect of oxytocin. PAX6 gene expression increased in the epithelium under the effect of oxytocin (2.1 times) on the 8th day, while MKI67 and TAB3 genes expression remained virtually unchanged compared to the control (0.72 and 1.1 times, respectively).

Conclusion. The authors have elucidated a new mechanism of action of oxytocin on the corneal restoration process during the damage of cornea. This mechanism represents differential stimulation of expression of MKI67 and PAX6 genes involved in the regeneration of stroma and corneal epithelium, respectively.

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