ABSTRACT
OBJECTIVE: To investigate the pathology underlying the ocular surface complications of patients with Stevens-Johnson syndrome (SJS) in the chronic stage. METHODS AND ANALYSIS: Using oligonucleotide microarrays, we performed comprehensive gene expression analysis of the conjunctival epithelium of patients with SJS in the chronic stage (n=3). The controls were patients with conjunctival chalasis (n=3). We confirmed the downregulation and upregulation of transcripts of interest by quantitative real-time PCR (RT-PCR) assay. The expression of ocular surface protein with significantly upregulated transcripts was assessed immunohistochemically. RESULTS: Compared with the controls, in the conjunctival epithelium of patients with SJS, 50 transcripts were downregulated by less than one-tenth (analysis of variance (ANOVA) p<0.05). Transcripts MUC7, PIGR, HEPACAM2, ADH1C and SMR3A were downregulated by less than one-fiftieth. 65 transcripts were upregulated more than 10- fold; the difference between patients with SJS and the controls was significant (ANOVA p<0.05). There were 14 transcripts that were upregulated more than 50-fold; they were SERPINB4, KRT1, KRTDAP, S100A7, SBSN, KLK6, SERPINB12, PNLIPRP3, CASP14, ODZ2, CA2, CRCT1, CWH43 and FLG. Quantitative RT-PCR of conjunctival epithelium samples from 11 patients with SJS and 26 controls showed that the gene expression of PIGR, HEPACAM2 and ADH1C was significantly downregulated while the gene expression of ODZ2 (teneurin-2) was significantly upregulated in patients with SJS. We document that teneurin-2 protein can be expressed in human conjunctival epithelium. CONCLUSION: Our results suggest that the downregulation of PIGR, HEPACAM2 and ADH1C and upregulation of teneurin-2 expression contribute to the pathology of the ocular surface in patients with SJS in the chronic stage.
ABSTRACT
The human ocular surface epithelium expresses TLR3, which recognizes double-stranded (ds) RNA mimicking polyinosine-polycytidylic acid (polyI:C). Its stimulation induces the secretion of the inflammatory cytokines such as interleukin (IL)-6, IL-8, and type I interferon. The cytoplasmic helicase proteins RIG-I and MDA5 are also expressed on the ocular surface. We investigated the function of TLR3 in the cornea of CD11c- YFP+ and TLR3 KO CD11c- YFP+ mice. We also examined the function of IPS-1, an adaptor molecule common to RIG-I and/or MDA5, in IPS-1 KO CD11c- YFP+ mice. In the central corneal epithelium of CD11c- YFP+ mice, the infiltration of CD11c- YFP+ cells was significantly upregulated 48 h after polyI:C stimulation; it was significantly downregulated in the stromal layer of their central and peripheral cornea. On the other hand, in the corneal epithelium of TLR3 KO CD11c- YFP+- and wild-type mice, the movement of CD11c- YFP+ cells was different from CD11c- YFP+ mice. This suggests that TLR3 knock-out (KO) interferes with their movement from the peripheral- to the central cornea or lymph nodes and that it may be similar in IPS-1 KO CD11c-YFP+ - and wild-type mice. Under normal conditions, the number of CD11c- YFP+ cells in the central and peripheral corneal epithelium, but not in the stromal layer, is significantly greater in TLR3 KO CD11c- YFP+- than CD11c- YFP+ mice. In IPS-1 KO CD11c- YFP+ mice, their number in the stromal layer, but not in the epithelium of the central and peripheral cornea, was significantly greater than in CD11c- YFP+ mice. Our findings suggest that CD11c+ dendritic cell (DC) migration in the corneal epithelium is regulated by TLR3, whereas CD11c+ DC migration in the stromal layer of the cornea is regulated by IPS-1. These observations, together with our earlier findings, imply that TLR3 and IPS-1 contribute distinctly to the regulation of innate immune responses and tissue inflammation elicited by CD11c+ DCs to maintain homeostasis in corneal tissues.
