CCN2/CTGF promotor activity in the developing and adult mouse eye

CCN2/CTGF is a matricellular protein that is known to enhance transforming growth factor-beta signaling and to induce a myofibroblast-like phenotype in a variety of cell types. Here, we investigated Ccn2/Ctgf promotor activity during development and in the adult mouse eye, using CTGF(LacZ/+) mice in which the beta-galactosidase reporter gene LacZ had been inserted into the open reading frame of Ccn2/Ctgf. Promotor activity was assessed by staining for beta-galactosidase activity and by immunolabeling using antibodies against beta-galactosidase. Co-immunostaining using antibodies against glutamine synthetase, glial fibrillary acidic protein, choline acetyltransferase, and CD31 was applied to identify specific cell types. Ccn2/Ctgf promotor activity was intense in neural crest-derived cells differentiating to corneal stroma and endothelium, and to the stroma of choroid, iris, ciliary body, and the trabecular meshwork during development. In the adult eye, a persistent and very strong promotor activity was present in the trabecular meshwork outflow pathways. In addition, endothelial cells of Schlemm's canal, and of retinal and choroidal vessels, retinal astrocytes, Muller glia, and starburst amacrine cells were stained. Very strong promoter activity was seen in the astrocytes of the glial lamina at the optic nerve head. We conclude that CCN2/CTGF signaling is involved in the processes that govern neural crest morphogenesis during ocular development. In the adult eye, CCN2/CTGF likely plays an important role for the trabecular meshwork outflow pathways and the glial lamina of the optic nerve head.

Automated summary

The promoter activity of Ccn2/Ctgf was found to be intense in specific cell types during mouse eye development, while in the adult eye, strong promoter activity was mainly observed in the trabecular meshwork outflow pathways and the glial lamina of the optic nerve head. This suggests that CCN2/CTGF signaling plays a crucial role in neural crest morphogenesis during ocular development as well as in maintaining the functionality of certain structures in the adult eye.