Detection And Analysis Of Donor Stem Cells After Limbal Stem Cell Transplantation In New-Zealand Rabbits

Objective To investigate the survival, proliferation and differentiationof donor-derived limbal stem cells in different periods after limbal stemcell transplantation(LSCT) and compare the effects between the limbalautograft transplantation and allograft transplantation. Moreover, thecorrelation between the survival of donor-derived limbal stem cell andthe reepithelization of cornea was presented so as to provide evidenceand evaluation for limbal stem cell transplantation.Methods Forty New-Zealand rabbits were divided into four groups: theautograft group, the allograft group, the cyclosporine A group and thecontrol group. Limbal stem cell deficiency were established by performinglimbectomy, corneal epithelial stem cells were obtained by autograft andallograft limbal stem cell transplantation respectively. Two rabbits weresacrificed in the first week, the second week, the first month, the secondmonth and the third month after transplantation respectively. Cornealsamples including the limbus were collected and fixed with 10% formalin,sections (4μm) of paraffin-embeded rabbit corneal tissues were analyzedby immunohistochemistry(S-P method ).Results In autograft group, the donor stem cells were still confined tothe limbus during the first week, whereas a well-differentiated cornealepithelium was recognized at the first month. three months later, a normalstratified corneal epithelium was restored , the stem cells wereabundantly expressed in the limbus. In comparison, the amount of markedstem cells decreased during the first week in the allograft group, andthere was nearly no epithelium covered in the first month. in the thirdmonth, the cornea was decompensated accompanied by chronic inflammation,persistent defects, stromal scaring and neovascularization. no stem cellwas detected However, the cyclosporine A group showed a better result thanthe allograft group, and there was a statistically significance betweenthe two groups. In control group, the paracentral cornea was recoveredwith donor-derived cells during the first week and the cornea wasreepithelizated in the first month.Conclusions the amount of limbal stem cells exert a direct influence uponthe outcome of reepithelization of cornea, effective ways of detectionof survival of limbal stem cell provide essential evidence for the resultsof limbal stem cell transplantation. Moreover, cyclosporine A iseffective in relieving immune rejection and ameliorating therapeuticeffect in limbal stem cell transplantation.