Genome-Wide Scleral Micro- and Messenger-RNA Regulation During Myopia Development in the Mouse.
OBJECTIVE
MicroRNA (miRNAs) have been previously implicated in scleral remodeling in normal eye growth. They have the potential to be therapeutic targets for prevention/retardation of exaggerated eye growth in myopia by modulating scleral matrix remodeling. To explore this potential, genome-wide miRNA and messenger RNA (mRNA) scleral profiles in myopic and control eyes from mice were studied.


METHODS
C57BL/6J mice (n = 7; P28) reared under a 12L:12D cycle were form-deprived (FD) unilaterally for 2 weeks. Refractive error and axial length changes were measured using photorefraction and 1310-nm spectral-domain optical coherence tomography, respectively. Scleral RNA samples from FD and fellow control eyes were processed for microarray assay. Statistical analyses were performed using National Institute of Aging array analysis tool; group comparisons were made using ANOVA, and gene ontologies were identified using software available on the Web. Findings were confirmed using quantitative PCR in a separate group of mice (n = 7).


RESULTS
Form-deprived eyes showed myopic shifts in refractive error (-2.02 ± 0.47 D; P < 0.01). Comparison of the scleral RNA profiles of test eyes with those of control eyes revealed 54 differentially expressed miRNAs and 261 mRNAs fold-change >1.25 (maximum fold change = 1.63 and 2.7 for miRNAs and mRNAs, respectively) (P < 0.05; minimum, P = 0.0001). Significant ontologies showing gene over-representation (P < 0.05) included intermediate filament organization, scaffold protein binding, detection of stimuli, calcium ion, G protein, and phototransduction. Significant differential expression of Let-7a and miR-16-2, and Smok4a, Prph2, and Gnat1 were confirmed.


CONCLUSIONS
Scleral mi- and mRNAs showed differential expression linked to myopia, supporting the involvement of miRNAs in eye growth regulation. The observed general trend of relatively small fold-changes suggests a tightly controlled, regulatory mechanism for scleral gene expression.
School of Optometry, University of California at Berkeley, Berkeley, California, United States.
Ravikanth
R
Metlapally
Department of Ophthalmology at Emory University, Atlanta, Georgia, United States.
Han Na
HN
Park
Department of Ophthalmology at Emory University, Atlanta, Georgia, United States 3Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Atlanta, Georgia, United States.
Ranjay
R
Chakraborty
School of Optometry, University of California at Berkeley, Berkeley, California, United States.
Kevin K
KK
Wang
Department of Ophthalmology at Emory University, Atlanta, Georgia, United States.
Christopher C
CC
Tan
Department of Ophthalmology at Emory University, Atlanta, Georgia, United States.
Jacob G
JG
Light
Department of Ophthalmology at Emory University, Atlanta, Georgia, United States 3Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Atlanta, Georgia, United States 4Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States.
Machelle T
MT
Pardue
School of Optometry, University of California at Berkeley, Berkeley, California, United States 5Vision Science Graduate Group University of California at Berkeley, Berkeley, California, United States.
Christine F
CF
Wildsoet
D000818:Animals; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D055106:Genome-Wide Association Study; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D009216:Myopia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012029:Refraction, Ocular; D012590:Sclera / Q000378:metabolism* / Q000473:pathology; D012683:Sensory Deprivation; D041623:Tomography, Optical Coherence
D035683:MicroRNAs; D012333:RNA, Messenger