Abstract
Purpose :
Keratoconus (KC) is a bilateral, asymmetric corneal degeneration characterized by localized thinning and protrusion of the cornea. KC usually commences in adolescence and progresses to the third or fourth decade of life, leading to significant impairments to both vision and quality of life. MicroRNAs (miRNAs) are small endogenous noncoding RNAs involved in silencing or regulation of gene expression at the translational and post-transcriptional levels. miRNAs have been reported in biological fluids (saliva, tears, aqueous humor and vitreous humor) and thus considered as biomarker candidates. Surprisingly, only a few studies have explored the role of miRNAs as it relates to the pathobiology of KC. Thus, the aim of this study was to determine the expression of salivary miRNAs in healthy and KC subjects.
Methods :
Preserved saliva samples collected from 16 healthy subjects (8 male and 8 female) and 50 KC subjects (25 male and 25 female) were collected for this study. Briefly, saliva was collected via passive drool in 15 mL tubes following rinsing with water. Samples were then aliquoted and preserved at -80°C prior to processing. The total RNA was extracted using Norgen’s Saliva/Swab RNA Purification Kit. PCR was performed using the TaqMan Advanced miRNA Assay Kit and TaqMan Advanced miRNA fixed labelled PCR plates. Data were analyzed using one-way ANOVA or t-test where necessary.
Results :
Thirty-two miRNAs were differentially expressed in saliva samples of healthy and KC subjects. Eight miRNAs, (has-miR-15b-5p, has-miR-30c-5p, ath-miR 159a, has-miR-93-5p, has-miR-27a-3p, has-miR-30e-5p, has-miR-30b-5p and has-miR-30a-5p) was significantly upregulated in healthy males only as compared to: healthy females and KC (male and females) subjects. However, expression of miRNAs between different sex (male and female) of healthy and KC subjects, showed no significant difference in our study.
Conclusions :
Our findings clearly showed the expression of miRNA in saliva samples of both healthy and KC subjects. Expression of miRNA in saliva identify their potential use as a biomarker for early-stage keratoconus detection and progressive keratoconus that would be a potential clinical advancement.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.