Aim To investigate the expression and function of interleukin-4 receptor α (IL-4Rα) in human conjunctival epithelial cells (HCjECs).
Methods The presence of IL-4Rα mRNA and protein was examined by reverse transcription (RT) PCR and immunohistology, respectively. Cell surface expression was examined by flow cytometry. The effects of interleukin (IL)-4 or IL-13 on the tyrosine phosphorylation of signal transducer and the activator of transcription 6 (STAT6) were evaluated by immunoblot analyses. The transcripts upregulated upon IL-4 stimulation were examined using GeneChip, and confirmed by quantitative RT-PCR.
Results IL-4Rα mRNA and protein were detected in human conjunctival epithelium. IL-4Rα protein was expressed on the cell surface of HCjECs. IL-4 and IL-13 induced tyrosine phosphorylation of STAT6. GeneChip analysis showed that nine transcripts were upregulated more than fourfold by IL-4 stimulation in the primary HCjECs from two individuals. Quantitative RT-PCR assay confirmed the upregulation of these transcripts: lecithin retinol acyltransferase (LRAT), calpain (CAPN14), tumour necrosis factor alpha-induced protein 6 (TNFAIP6), RAS guanyl-releasing protein 1 (RASGRP1), endothelin receptor type A (EDNRA), hyaluronan synthase 3 (HAS3), cathepsin C (CTSC), carbonic anhydrase II (CA2) and cytokine-inducible SH2-containing protein (CISH).
Conclusions HCjECs expressed functioning IL-4Rα, and IL-4 stimulation induced the expression of several genes.
- Interleukin-4 receptor α (IL-4Rα)
- human conjunctival epithelial cells (HCjEC)
- gene expression analysis
- ocular surface
- experimental & laboratory
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Funding This work was supported in part by grants-in-aid for scientific research from the Japanese Ministry of Health, Labour and Welfare, the Japanese Ministry of Education, Culture, Sports, Science and Technology, CREST from JST, a research grant from the Kyoto Foundation for the Promotion of Medical Science, the Intramural Research Fund of Kyoto Prefectural University of Medicine, a Shiseido Female Researcher Science Grant and a research grant from the Japan Allergy Foundation.
Competing interests None.
Patient consent Obtained.
Ethics approval This study was conducted with the approval of the Institutional Review Board at Kyoto Prefectural University of Medicine, Kyoto, Japan. All experimental procedures were conducted in accordance with the tenets of the Declaration of Helsinki.
Provenance and peer review Not commissioned; externally peer reviewed.