Abstract
Purpose :
We previously showed that the pregnancy hormone relaxin 2 increases corneal epithelial wound healing by influencing migration and proliferation. To investigate the influence of relaxin 2 on keratocytes and its potential effect on the stroma.
Methods :
Primary keratocytes were isolated and cultured from transplant residuals of donor corneae. Keratocytes were stimulated with 1 nM relaxin and in combination with 3 ng/ml tissue growth factor β (TGFβ) for 48 hours. Differentiation of keratocytes to myofibroblasts was investigated by smooth muscle actin (SMA) expression with the help of western blot analysis and concomitant contractility by collagen gel contraction assays. Lumigan, collagens 1A and 1B mRNA expressions were evaluated by real-time RT-PCR and collagen production was measured in supernatants by sircol soluble collagen assay.
Results :
Relaxin 2 alone does not influence the SMA expression, but 10 nM relaxin 2 in combination with TGFβ increases the SMA expression compared to TGFβ alone. Relaxin 2 does not further increases TGFβ-induced contractility of keratocytes. TGFβ-elevated collagen 1A expression was reduced by relaxin 2, whereas collagen 1B and lumigan expression was not influenced by relaxin 2. Total collagen content measured in supernatants was not influenced by relaxin 2.
Conclusions :
Case reports of corneal decompensation during pregnancy accuse elevated relaxin levels. Our findings do not support this theory. Relaxin 2 alone does not influence keratocytes. However, in combination with TGFβ relaxin 2 can increase wound healing processes of the corneal stroma.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.