Conjunctival MicroRNA expression in inflammatory trachomatous scarring

Area of Science:

• Ophthalmology
• Molecular Biology
• Genetics

Background:

• Trachoma is a leading cause of preventable blindness, affecting millions globally.
• The exact mechanisms driving trachoma pathogenesis, a fibrotic conjunctival disease caused by Chlamydia trachomatis, are not fully understood.
• Epigenetic modifications, such as microRNA (miR) expression, may play a role in disease development.

Purpose of the Study:

• To investigate host microRNA (miR) expression profiles in different stages of trachoma.
• To identify specific miRs associated with conjunctival inflammation and scarring in trachoma patients.
• To explore the potential role of differentially expressed miRs in the pathogenesis of trachoma.

Main Methods:

• Conjunctival swab specimens were collected from individuals in The Gambia with healthy conjunctiva (N), conjunctival scarring without inflammation (TS), and conjunctival scarring with inflammation (TSI).
• MicroRNA expression was analyzed using Taqman qPCR array, with network and pathway analysis performed.
• Seven differentially expressed miRs were selected for validation in an independent cohort using qPCR.

Main Results:

• Array screening identified 82 differentially expressed miRs between the phenotypic groups.
• Predicted mRNA targets of these miRs were enriched in pathways related to fibrosis and epithelial cell differentiation.
• Validation confirmed that miR-147b is significantly up-regulated in TSI versus N, and miR-1285 is up-regulated in TSI versus TS.

Conclusions:

• miR-147b and miR-1285 are significantly up-regulated in individuals with inflammatory trachomatous scarring.
• These findings suggest a role for miR-147b and miR-1285 in the inflammatory processes underlying trachoma.
• Further research into the function of these miRs could elucidate trachoma pathogenesis and inform therapeutic strategies.