Effect Of Mechanical Tension On Terminal Differentiation Of Conjunctival Epithelial Cells And Its Mechanism

Purpose:In this study,the effect of mechanical tension on the terminal differentiation of conjunctival epithelial cells was investigated by applying certain mechanical tension on conjunctival tissues.Methods:Normal adult New Zealand rabbits were used as experimental animals.Bulbar conj unctival tissue about 4mm x 8mm in size between the superior rectus muscle and the inner canthus of the right eye was selected,which was tightened and sutured to fix the sclera.And the bulbar conjunctival tissue of the left eye in the same position was simply sutured as the sham operation group.On the 3rd,7th and 14th days after suture,slit lamp photography was performed.HE staining,PAS staining,TUNEL staining,immunofluorescence staining,real-time PCR and western blot were used to detect relevant indicators and observe the changes in structure and function of conjunctival tissue.At the same time,the conjunctival tissue of normal adult New Zealand rabbits was taken and given a certain tension during in vitro culture.The changes of related indexes were detected after conjunctival tissues culture for 1,3 and 7 days.Results:The conjunctival epithelium of the experimental animals were intact and there were no obvious inflammatory cell infiltration and apoptosis.Compared with the normal group and the sham group,the number and density of goblet cells in the experimental group were significantly reduced,and the expression of MUC5AC and K7 in the conjunctival epithelium decreased,while the expression ofK3/K12(a specific marker of corneal epithelium)increased.The RT-PCR showed that the expression of the YAP1 gene in YAP/TAZ signaling pathway decrease in the experimental group,and the expression of some genes in the TRP channel also changes.Except that K3/K12 did not obviously express and the expression of YAP1/TAZ increased in conjunctival tissues cultured in vitro under tension,the results were consistent with those of animal experiments.Conclusions:Mechanical tension can regulate the terminal differentiation direction of the conjunctival epithelial cells,causing the conjunctival epithelial cells to lose goblet cell differentiation and differentiate into the corneal epithelium.Mechanical tension may be an important regulator of the differentiation of ocular epithelial cells.