Abstract
Purpose :
This study investigated the effect on bone morphogenetic protein (BMP) gene expression in chick retinal pigment epithelium (RPE) of simultaneous competing retinal defocus of opposite sign.
Methods :
14-day old White-Leghorn chicks wore monocular Fresnel lenses of alternating powers (+10D/-10D) for 15 min, 2 h, and 3 days. qPCR was used to quantify differential gene expression in chick RPE for BMP2, 4, and 7.
Results :
Gene expression was up-regulated for BMP2 and BMP4, after short periods of lens wear. BMP2 and BMP4 gene expression was up-regulated 199 ± 11% and 147 ± 26 % respectively after as short as 15 min exposure, with 2 h of treatment inducing much greater changes for both BMP2 (944 ± 244%) and BMP4 (229 ± 31%). However, neither BMP2 or BMP4 showed significant differential gene expression after 3 days of treatment (BMP2, 116 ± 31%; BMP4, 114 ± 21%). The BMP7 gene did not show differential expression under any of the treatment conditions.
Conclusions :
Expression of both BMP2 and BMP4 genes in chick RPE is sensitive to retinal defocus manipulations. That both showed early up-regulation with simultaneous competing retinal defocus of opposite sign is consistent with observed slowing of ocular growth, as is also characteristic of imposed myopic defocus alone. Thus RPE-BMP2/4 gene expression changes represent robust predictors of ocular growth changes. The results also further implicate these growth factors in the molecular signaling pathways mediating slowed eye elongation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.