Abstract
Purpose:
DNA methylation plays critical roles in physiological and pathological processes. Recent studies implicated DNA methylation was associated with scleral remodeling in mouse myopia model. In order to elucidate the role of DNA methylation in myopia development, DNA methylation Chip was carried out in mice for form deprived myopia.
Methods:
C57BL/6J mice (n=60, P21), reared in standard mouse cages with a 12 h:12 h light-dark cycle, 30 mice were form-deprived (FD) unilaterally for 4 weeks,30 mice as normal controls was maintained free of form deprivation for the same four-week period. The study was approved by the Animal Care and Ethics Committee at Wenzhou Medical University (Wenzhou, China). The experiments were conducted in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. The refractive state was measured in a dark room with an eccentric infrared photorefractor and axial length measurements were made using a custom-built optical coherence tomography instrument. Pooled Scleral DNA samples from FD and control eyes were processed for DNA methylation Chip. Original Data analysis was performed using Nimblescan 2.5 software. Go, pathway analysis was carried out by bioinformatics’ tools.
Results:
Comparison scleral DNA methylation for FDM and control eyes, 228 difference genes were revealed, 89 genes were hypermethylated, and 139 genes were hypomethylated. These genes were further analyzed for significant go, pathway (p<0.05), which mainly involved in Lipoic acid metabolism, Fatty acid metabolism, Retinol metabolism, Ubiquinone and other terpenoid-quinone biosynthesis, and so on. Scleral synthesis and degradation of type I collagen is the key to myopia. DNA methylation of COL1α1 promoter region was analyzed by Bisulfite Specific PCR (BSP) and Sanger Sequencing, some CpG sites showed that hypermethylation in FD than normal eyes, total methylation level in FD and normal eye, negative correlate with their changed mRNA levels. DNA methylation may be involved in the transcriptional regulation of COL1α1 in sclera.
Conclusions:
A great number of scleral DNA methylation difference genes were revealed in mice for form deprived myopia, DNA methylation may be involved in occurrence and development of myopia, but the exact molecular pathogenesis need further study