Abstract
Purpose :
A variety of inflammatory mediators have already been reported to be involved in dry eye (DE) using classical detection methods. The NanoString's nCounter™ analysis system offers a powerful multiplexing tool to assess rapidly the gene expression of a wide range of mediators directly at the cell levels We investigated the interest of this method to detect mRNA signature in conjunctival imprints (CI) of inflammatory proteins and transcripts known to be modulated in DE patients.
Methods :
Conjunctival cells were collected by CI in 15 healthy patients and 30 DE patients defined by a set of clinical signs and symptoms. Total RNAs were extracted and NanoString's nCounter™ technology with an inflammatory human Code Set was used to analyze the genes of 34 proteins. The fold change of mean with a cut-off ≥1.5 was chosen to select the differentially expressed genes in both groups. Mann-Whitney non-parametric statistical test was used.
Results :
Of these 34 genes tested by the code set, 21 genes were detected. Up-regulated genes expressed with a fold change ranging from 1.4 to 16.7 such as IL-6, HLA-DRA, HLA-DRB, CXCL9, CXCL10, CCL4, CCL5, AREG, STAT1, IFIT3 and CCR1, clearly distinguished between SS patients and normal subjects, whereas IL-8, TNFα, CCL3, IFNg, TLR4, NR3C1, TGFb, ALOX15, MYC and TLR5 did not show any significant difference between groups. The remaining genes including CCL2, CXCL5, IL-1a, IL-1b, IL-2, IL-4, IL-12, IL-13, IL-17, IL-21, TGFb2, TLR9 and MMP9 were not detected.
Conclusions :
These up-regulated genes may play an important role in the altered gene expression in the conjunctival epithelium and provide valuable insight into biological mechanisms underlying the pathogenesis of DE. The NanoString's nCounter™ analysis system that directly quantifies mRNA copies could detect targets identified by conventional proteomic and transcriptomic methods, and highlight multiplexing possibilities of this technology.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.