Abstract
Purpose :
We previously reported that loss of β-catenin in corneal stromal keratocytes triggered corneal precocious maturation, coincident with up-regulation of various growth factors including BMP4 and TGFβ3. This study attempts to examine the potential roles of TGFβ3 during cornea development.
Methods :
Primary corneal stroma fibroblasts were treated with BMP4, TGFβ3 or PBS (control) and related gene expressions were determined by qRT-PCR and western blots. In addition, either BMP4 or TGFβ3 was injected subcutaneously into C57BL6 neonates from postnatal day 0 (P0) to P7. Mice were sacrificed at P8 and were subjected to histological examinations by HE staining and TEM. Gene expressions were determined by western blots and IHC immunostaining.
Results :
BMP4 injection causes mouse epithelial layer increase to more than 10 layers instead of 1-2 cell layers in littermate control mice, while it has no influence on stromal maturation. On the other hand, TGFβ3 promotes corneal stromal maturation but has little effect on epithelial cell stratification and differentiation. Primary cell culture experiments showed that the expressions of Col1a1, Kera and Lum were ≥2-fold increased after TGFβ3 treatment for 24hrs in the corneal stromal fibroblasts, while no increases were detected after BMP4 treatment. TEM revealed that TGFβ3 promotes mouse corneal stroma maturation by increasing stromal cell density and cell activates (more ER and Golgi), extracellular matrix formation/organization.
Conclusions :
These data suggested that canonical Wnt signaling modulates Bmp4 and TGFβ3 expression which in turn facilitate epithelial stratification and stromal maturation during corneal development.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.