Gene expression analysis of conjunctival epithelium of patients with Stevens-Johnson syndrome in the chronic stage

Alteration of Gene Expression in Pathological Keratinization of the Ocular Surface

Purpose

To investigate the molecular mechanism of pathological keratinization in the chronic phase of ocular surface (OS) diseases.

Methods

In this study, a comprehensive gene expression analysis was performed using oligonucleotide microarrays on OS epithelial cells obtained from three patients with pathological keratinization (Stevens-Johnson syndrome [n = 1 patient], ocular cicatricial pemphigoid [n = 1 patient], and anterior staphyloma [n = 1 patient]). The controls were three patients with conjunctivochalasis. The expression in some transcripts was confirmed using quantitative real-time PCR.

Results

Compared to the controls, 3118 genes were significantly upregulated by a factor of 2 or more than one-half in the pathological keratinized epithelial cells (analysis of variance P < 0.05). Genes involved in keratinization, lipid metabolism, and oxidoreductase were upregulated, while genes involved in cellular response, as well as known transcription factors (TFs), were downregulated. Those genes were further analyzed with respect to TFs and retinoic acid (RA) through gene ontology analysis and known reports. The expression of TFs MYBL2, FOXM1, and SREBF2, was upregulated, and the TF ELF3 was significantly downregulated. The expression of AKR1B15, RDH12, and CRABP2 (i.e., genes related to RA, which is known to suppress keratinization) was increased more than twentyfold, whereas the expression of genes RARB and RARRES3 was decreased by 1/50. CRABP2, RARB, and RARRES3 expression changes were also confirmed by qRT-PCR.

Conclusions

In pathological keratinized ocular surfaces, common transcript changes, including abnormalities in vitamin A metabolism, are involved in the mechanism of pathological keratinization.

The existence of senescent cells in conjunctival epithelium from elderly individuals

PURPOSE

The ocular surface microenvironment changes with aging. However, it remains unclear if cellular senescence influences the ocular surface. We investigated the presence of p16INK4a-expressing senescent cells in healthy human conjunctiva.

STUDY DESIGN

Clinical and experimental.

METHODS

Healthy conjunctival tissue samples were obtained from middle-aged and elderly subjects. RT-qPCR was performed to assess the expression of senescence markers CDKN2A (p16INK4a) and CDKN1A (p21CIP1/WAF1) and immunostaining was performed to examine the expression of the senescence marker p16INK4a, stem cell markers Ki67 and p63, tight-junction marker ZO-1.

RESULTS

Our study involved 19 conjunctival tissue samples (10 elderly and 9 middle-aged), mean age [elderly: 75.8 ± 3.7 years (72-81), middle-aged: 52.7 ± 7 years (38-59)], sex (elderly: 3 men, 7 women; middle-aged: 3 men, 6 women). The expression of p16INK4a was significantly increased at the RNA level in the elderly compared to middle-aged (p < 0.05). Positivity rate of p16INK4a was significantly elevated in the elderly (15.0 ± 7.8%) compared to middle-aged (0.2 ± 0.6%) (p < 0.05). Positivity rate of Ki67and p63 was significantly reduced in the elderly (1.7 ± 1.7% and 16.5 ± 9.5%) compared to middle-aged (3.9 ± 1.8% and 24.7 ± 5.7%) (p < 0.05). ZO-1 expression was reduced in tissue samples showing p16INK4a-positivity but retained in tissue samples in which p16INK4a was undetectable.

CONCLUSIONS

Senescent cells accumulate with age in the conjunctival epithelium, accompanied by a decrease in Ki67, p63 and ZO-1 expressing cells.

Once-Daily Topical Phosphosulindac Is Efficacious in the Treatment of Dry Eye Disease: Studies in Rabbit Models of Its Main Clinical Subtypes

Purpose: Dry eye disease (DED) is classified as aqueous deficient, evaporative, or mixed. We investigated the therapeutic effect of the novel anti-inflammatory drug phosphosulindac (PS) in rabbit models of DED encompassing its pathogenesis, and its transition to chronicity.

Methods: We treated three rabbit models of DED with PS (hydrogel formulation) or vehicle topically applied 1 × /day. We induced aqueous-deficient DED (acute and chronic) by injecting Concanavalin A into lacrimal glands; evaporative DED by injecting into the upper eyelid inactivated Mycobacterium tuberculosis in complete Freund's adjuvant; and mixed DED through desiccative stress, induced by holding open the eye for 3 h. We determined corneal sensitivity, tear break-up time (TBUT), Schirmer's tear test (STT), tear osmolality, and fluorescein staining of the ocular surface.

Results: PS reversed all abnormal DED parameters. In acute DED, PS dose dependently normalized corneal sensitivity and tear osmolality; and improved TBUT, STT, and fluorescein staining. PS normalized corneal sensitivity and improved all other parameters in chronic aqueous-deficient DED. In evaporative DED, PS normalized corneal sensitivity and improved TBUT and fluorescein staining (osmolality and STT were not significantly changed in this model). In the desiccative stress model, PS improved TBUT and fluorescein staining but had no effect on STT or tear osmolality.

Conclusions: PS rapidly reversed almost all DED parameters in its three subtypes. The normalization of the suppressed corneal sensitivity suggests the possibility of marked symptomatic relief by PS. The hydrogel formulation allows once-daily dosing. PS merits further development as a potential treatment for DED.

Transcriptome Analysis of Pterygium and Pinguecula Reveals Evidence of Genomic Instability Associated with Chronic Inflammation

Solar damage due to ultraviolet radiation (UVR) is implicated in the development of two proliferative lesions of the ocular surface: pterygium and pinguecula. Pterygium and pinguecula specimens were collected, along with adjacent healthy conjunctiva specimens. RNA was extracted and sequenced. Pairwise comparisons were made of differentially expressed genes (DEGs). Computational methods were used for analysis. Transcripts from 18,630 genes were identified. Comparison of two subgroups of pterygium specimens uncovered evidence of genomic instability associated with inflammation and the immune response; these changes were also observed in pinguecula, but to a lesser extent. Among the top DEGs were four genes encoding tumor suppressors that were downregulated in pterygium: C10orf90, RARRES1, DMBT1 and SCGB3A1; C10orf90 and RARRES1 were also downregulated in pinguecula. Ingenuity Pathway Analysis overwhelmingly linked DEGs to cancer for both lesions; however, both lesions are clearly still benign, as evidenced by the expression of other genes indicating their well-differentiated and non-invasive character. Pathways for epithelial cell proliferation were identified that distinguish the two lesions, as well as genes encoding specific pathway components. Upregulated DEGs common to both lesions, including KRT9 and TRPV3, provide a further insight into pathophysiology. Our findings suggest that pterygium and pinguecula, while benign lesions, are both on the pathological pathway towards neoplastic transformation.

Human leucocyte antigen association of patients with Stevens-Johnson syndrome/toxic epidermal necrolysis with severe ocular complications in Han Chinese

BACKGROUND/AIMS

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) induced by cold medicine (CM) may result in severe ocular complications (SOCs). The purpose of this study was to investigate the human leucocyte antigen (HLA) polymorphism pattern in CM-induced patients with SJS/TEN developing SOCs.

METHODS

All participants, including patients with SJS/TEN (n=33) and control patients (n=98), were enrolled through visits to the clinic from 2016 to 2017. SOCs were diagnosed (n=26) via a chart review or eye examination. Patient saliva was collected with commercialised kits and genotyped with PCR assays followed by hybridisation with sequence-specific oligonucleotide (SSO) probes (PCR-SSO) using commercial bead-based typing kits.

RESULTS

In all patients with SJS/TEN with SOCs, the HLA-A*02:07 carrier frequency was significantly higher than that in controls (OR=3.24, 95% CI=1.09 to 9.60, p=0.049), as was the genotype frequency (OR=3.89, 95% CI=1.49 to 10.16, p=0.007). In patients with CM-SJS/TEN with SOCs, the HLA-A*02:07 carrier frequency was higher than that in controls (OR=5.56, 95% CI=1.52 to 20.00, p=0.016), as was the allele frequency (OR=6.67, 95% CI=2.33 to 20.00, p=0.001). In patients with CM-SJS/TEN with SOCs, the HLA-B*46:01 allele frequency was significantly higher than that in controls (OR=3.85, 95% CI=1.52 to 10.00, p=0.008).

CONCLUSIONS

The HLA-A*02:07 and HLA-B*46:01 alleles were significantly associated with SOCs among Han Chinese patients with CM-SJS/TEN. These findings demonstrate the genetic diversity in SJS pathogenesis among different ethnic groups.

Regulation of gene expression by miRNA-455-3p, upregulated in the conjunctival epithelium of patients with Stevens-Johnson syndrome in the chronic stage

To investigate the role of miRNA in the pathogenesis underlying ocular surface complications in patients with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) in the chronic stage. Using oligonucleotide microarrays, we performed comprehensive miRNA analysis of the conjunctival epithelium of SJS/TEN patients with severe ocular complications (SOC) in the chronic stage (n = 3). Conjunctival epithelium of patients with conjunctival chalasis (n = 3) served as the control. We confirmed the down- and up-regulation of miRNA of interest by quantitative real-time polymerase chain reaction (RT-PCR) assays using the conjunctival epithelium from 6 SJS/TEN with SOC patients and 7 controls. We focused on miRNA-455-3p, which is significantly upregulated in the conjunctival epithelium of the SJS/TEN patients, and investigated its function by inhibiting miR-455-3p in primary human conjunctival epithelial cells (PHCjEs). Comprehensive miRNA expression analysis showed that the expression of 5 kinds of miRNA was up-regulated more than fivefold, and that the expression of another 5 kinds of miRNA was down-regulated by less than one-fifth. There was a significant difference between the SJS/TEN patients and the controls [analysis of variance (ANOVA) p < 0.05]. Quantitative miRNA PCR assay showed that hsa-miR-31* and hsa-miR-455-3p were significantly up-regulated in the conjunctival epithelium of the SJS/TEN patients. Comprehensive gene expression analysis of PHCjEs transfected with the hsa-miR-455-3p inhibitor and quantitative RT PCR assay showed that ANKRD1, CXCL8, CXCL2, GEM, PTGS2, RNASE8, IL6, and CXCL1 were down-regulated by the hsa-miR-455-3p inhibitor. Quantitative RT-PCR, focused on the genes that tended to be up-regulated in SJS/TEN with SOC, revealed that the expression of IL1A, KPRP, IL36G, PPP1R3C, and ADM was significantly down-regulated in PHCjEs transfected with the hsa-miR-455-3p inhibitor. Our results suggest that miRNA-455-3p could regulate many genes including innate immune related genes in human conjunctival epithelium, and that its up-regulation contributes to the pathogenesis on the ocular surface in SJS/TEN patients with the SOC in the chronic stage. Our findings may lead to the development of new treatments using the miRNA-455-3p inhibitor.