Conjunctival transcriptomics in ocular mucous membrane pemphigoid

Jesse Panthagani; Kusy Suleiman; Rachel C Vincent; Hon Shing Ong; Graham R Wallace; Saaeha Rauz

doi:10.1016/j.jtos.2023.09.005

Conjunctival transcriptomics in ocular mucous membrane pemphigoid

Ocul Surf. 2023 Oct:30:142-149. doi: 10.1016/j.jtos.2023.09.005. Epub 2023 Sep 9.

Authors

Jesse Panthagani¹, Kusy Suleiman¹, Rachel C Vincent², Hon Shing Ong³, Graham R Wallace², Saaeha Rauz⁴

Affiliations

¹ Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK; Birmingham and Midland Eye Centre, Sandwell and West Birmingham NHS Trust, Birmingham, UK.
² Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK.
³ Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore; Corneal and External Diseases Department, Singapore National Eye Centre, Singapore, Singapore; Ophthalmology & Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.
⁴ Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK; Birmingham and Midland Eye Centre, Sandwell and West Birmingham NHS Trust, Birmingham, UK. Electronic address: s.rauz@bham.ac.uk.

PMID: 37690517
DOI: 10.1016/j.jtos.2023.09.005

Abstract

Purpose: Ocular Mucous Membrane Pemphigoid (OcMMP) is an orphan disease characterized by chronic autoimmune-driven conjunctival inflammation leading to progressive scarring, debilitating symptoms, and blinding sequelae. This feasibility study aims to demonstrate conjunctival genetic transcriptomic analyses as a putative tool for interrogation of pathogenic signaling pathways in OcMMP.

Methods: Conjunctival RNA profiling using the NanoString nCounter Human Fibrosis panel was undertaken on RNA extracted from conjunctival swabs obtained from 6 MMP patients (8 eyes; 4 M/2F; median age 78 [range 64-84] years); and 8 age-matched control participants (15 eyes; 3 M/5F; median age 69.5 [range 69-88] years). Data from 770 genes were analyzed with ROSALIND HyperScale architecture and stratified according to the level of clinically visible bulbar conjunctival inflammation. Normalization, fold-changes (≥+1.5-fold or ≤ -1.5-fold) and p-values adjustment (<0.05) using the Benjamini-Hochberg method were calculated.

Results: 93 differentially expressed genes (DEGs) were observed between OcMMP versus controls of which 48 were upregulated, and 45 downregulated. The top 4 upregulated DEGs represented fibrosis (COL3A1, COL1A1, FN1 and THBS1) while the key under-expressed genes (SCIN, HMGS2, XCL1/2) were indicative of ocular surface failure (goblet cell loss, keratinization, vulnerability to secondary infections). Forty-four pathways had a global significance score ≥2, the most significant being those related to extracellular matrix (ECM) remodeling, synthesis, and degradation. These pathways were accentuated in eyes with visible inflammation.

Conclusions: NanoString methodology acquired via a simple conjunctival swab identifies profibrotic genes in OcMMP group and differentiates inflamed eyes. Longitudinal sampling and following investigative intervention will further mechanistic insight and development of novel biomarkers to monitor disease progression.

Keywords: ALDH1A3; Fibrosis; Inflammation; NanoString; Scarring.

MeSH terms

Aged
Aged, 80 and over
Conjunctiva / pathology
Conjunctival Diseases* / metabolism
Conjunctivitis*
Fibrosis
Gene Expression Profiling
Humans
Inflammation / metabolism
Middle Aged
Mucous Membrane
Pemphigoid, Benign Mucous Membrane* / genetics
Pemphigoid, Bullous* / complications
Pemphigoid, Bullous* / metabolism
Pemphigoid, Bullous* / pathology
RNA / metabolism

Substances

RNA