Expression Profiles of CircRNA and mRNA in Lacrimal Glands of AQP5–/– Mice With Primary Dry Eye

Abstract

Purpose: This work aimed to identify differentially expressed circular RNAs (circRNAs) and elucidate their potential function in aquaporin 5 (AQP5) knockout (AQP5 −/−) mice with the primary dry eye phenotype. Methods: A slit lamp examination was performed on AQP5 −/− mice to assess corneal epithelial defects using fluorescein sodium staining. Hematoxylin-eosin staining and transmission electron microscopy analysis were performed to identify structural changes in lacrimal gland epithelial cells due to AQP5 deficiency. The expression profiles of circRNA and messenger RNA (mRNA) were determined by a microarray analysis. The selected circRNA was verified by quantitative real-time reverse transcriptionpolymerase chain reaction (qRT-PCR). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the biological functions and the potential pathways of parental genes involved in lacrimal gland epithelial cell changes. According to the bioinformatics analysis of identified circRNAs, we predicted a circRNA-miRNA-mRNA network of phagosomes. Results: The AQP5 −/− mice spontaneously exhibit dry eye symptoms, wherein the AQP5 deficiency changes the structure of lacrimal gland epithelial cells. The analysis revealed that, compared to AQP5 +/+ mice, 30 circRNAs in the lacrimal glands of AQP5 −/− mice were differentially expressed (fold change ≥ 2.0, p < 0.05). Nine upregulated circRNAs were identified using qRT-PCR, and nine upregulated validated circRNAs, 40 altered microRNAs (miRNAs), and nine upregulated mRNAs were identified through a network analysis. The KEGG analysis showed that these nine target genes were expressed in phagosomes. Conclusion: The AQP5 −/− mice have primary and stable dry eye phenotypes from birth. We identified differently expressed circRNAs in the lacrimal glands of AQP5 −/− and AQP5 +/+ mice, predicting a circRNA-miRNA-mRNA network of phagosomes. CircRNA likely plays an important role in lacrimal gland epithelial cell pathogenesis. Therefore, it is reasonable to use circRNA as a potential therapeutic agent for the treatment of dry eyes.

Lacrimal Gland Microenvironment Changes After Obstruction of Lacrimal Gland Ducts

“…AQP5 plays an important role in maintaining lacrimal gland homeostasis and tear secretion and will lead to the development of dry eye when AQP5 is deficient. 25 , 26 We found that short-term duct obstruction promoted AQP5 expression at the acinar apex, but long-term obstruction resulted in irreversible reduction of AQP5. The nerve is also essential in maintaining the normal secretory function of the lacrimal gland.…”

Bioinformatics identification of the candidate microRNAs and construction of a competing endogenous RNA regulatory network in lacrimal gland adenoid cystic carcinoma high‑grade transformation

“…ncRNAs have an essential role in the function of oncogenes or tumor suppressor genes in cell signaling pathways. Previous studies have shown that ncRNAs can affect gene expression through RNA-RNA crosstalk-based ceRNA regulatory networks by competing for the miRNA response elements of miRNAs through an indirect post-transcriptional mechanism ( 28 – 30 ). miRNAs and circRNAs not only promote tumor progression, but it can also create the conditions that are not conducive to tumor development, thereby inhibiting tumor progression.…”

Ocular Surface Ion-Channels Are Closely Related to Dry Eye: Key Research Focus on Innovative Drugs for Dry Eye

“…AQPs and anti-AQPs autoantibodies have been confirmed to be involved in the pathogenesis of Sjögren's syndrome ( 83 ). Liu et al reported that AQP5-/- mice can spontaneously develop DE symptoms, in which AQP5 deficiency changes the structure of lacrimal gland epithelial cells ( 84 ). Mucin secreted by conjunctival goblet cells (mainly MUC5AC) is a key condition for tear film stability.…”