Expression of the interleukin-4 receptor alpha in human conjunctival epithelial cells.
OBJECTIVE
To investigate the expression and function of interleukin-4 receptor alpha (IL-4Ralpha) in human conjunctival epithelial cells (HCjECs).


METHODS
The presence of IL-4Ralpha 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-4Ralpha mRNA and protein were detected in human conjunctival epithelium. IL-4Ralpha 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-4Ralpha, and IL-4 stimulation induced the expression of several genes.
Ueta
Mayumi
M
Department of Ophthalmology, Kyoto Prefectural University of Medicine, 465 Kajiicho, Hirokoji, Kawaramachi, Kamigyoku, Kyoto 602-0841, Japan. mueta@koto.kpu-m.ac.jp
Mizushima
Katsura
K
Yokoi
Norihiko
N
Naito
Yuji
Y
Kinoshita
Shigeru
S
D002154:Calpain / Q000378:metabolism; D003228:Conjunctiva / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D018793:Interleukin-13 / Q000494:pharmacology; D015847:Interleukin-4 / Q000378:metabolism / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D010766:Phosphorylation; D019948:Receptors, Interleukin-4 / Q000378:metabolism / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050800:STAT6 Transcription Factor / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation
D018793:Interleukin-13; D019948:Receptors, Interleukin-4; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D014157:Transcription Factors; D015847:Interleukin-4; C000602625:CAPN14 protein, human; D002154:Calpain