Influence of Vitamin A deficiency on the transcriptomic profile of rat meibomian glands.

PURPOSE: Vitamin A deficiency (VAD) is associated with chalazion in young children. However, the underlying molecular mechanism remains unclear. In the present study, transcriptome data from rat meibomian glands (MGs) were analyzed to reveal specific molecular responses to VAD.

METHODS

Total RNA was extracted and purified for library preparation and transcriptome sequencing. Differentially expressed genes (DEGs) between vitamin A normal (VAN) and VAD rats were analyzed using DESeq software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed using the GO seq R package and KOBAS software. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the RNA sequencing results.

RESULTS

The number of DEGs in the VAD group compared to the VAN group was 3129 (1531 upregulated and 1598 downregulated) in the rat MGs. VAD upregulated a large number of lipid metabolism-related genes. GO analysis showed that the most enriched and meaningful terms were related to lipid metabolism (e.g., "oxidation-reduction process, GO: 0,055,114," "lipid metabolic process, GO: 000,662"). KEGG pathway analysis showed that most of the enriched signaling pathways were involved in lipid metabolism, including the PPAR signaling pathway associated with retinoic acid (RA)-mediated nuclear receptors.

CONCLUSION

These findings demonstrate that VAD regulates the expression of numerous genes in the rat MG and that many of these genes are involved in lipid metabolic pathways.