Abstract
Purpose:
The aim of this study is to establish the effects of a human amniotic membrane (HAM) treatment by retinoids (active derivatives of vitamin A); just before its graft on a corneal alkali burn using a mouse model.
Methods:
This protocol was approved by the regional ethic committee (CEMEA Auvergne). Thirty eyes of male mice, dispatched into 5 groups: the first group was untreated, the others received a treatment by HAM grafts prepared according to four different conditions and one control: non cultivated (control group), cultivated during 24 hours in a standard culture medium, cultivated in a culture medium containing all-trans retinoic acid (ATRA) dissolved in dimethylsulfoxide (DMSO) and cultivated in a culture medium containing DMSO. Induction of HAM by ATRA was assessed by PCR quantification of RARβ (already published as a gene induced by retinoids). The photographs evaluated corneal re-epithelialization, histopathology evaluated ulceration depth, immunohistochemical analysis and signal quantification numbered the expression of MMP9 and VEGF.
Results:
For the ulcers surface, we noted a significant difference between the groups HAM cultivated during 24 hours without or with ATRA compared to the untreated group; and any significant difference between the group HAM cultivated in a medium containing DMSO and the untreated group. Concerning the ulcers depth, there was a significant difference between the group treated by HAM cultivated 24 hours with ATRA compared to the untreated group. Immunohistochemistry assays showed that MMP 9 and VEGF expression were decreased in the groups treated with HAM cultivated during 24 hours with ATRA compared to the other groups.
Conclusions:
The positive effects of HAM culture show its biological effect more than its mechanical effect. DMSO appears to reduce the effect of ATRA, implying quickly the use of a new non-toxic vector for clinical applications. Nevertheless, our results clearly showed that the induction of MAH by ATRA appears to have a beneficial effect on the ulcers depth and the expression of MMP 9 and VEGF. Our preliminary results are really promising in order to propose a positive engineering of HAM applied for wound healing graft on cornea in the next future.
Keywords: 480 cornea: basic science •
765 wound healing •
554 immunohistochemistry