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RNase‐7 expression mediated by IL‐1 beta in human ocular surface cells via multiple signalling pathways
Author(s) -
MOHAMMED I,
ABEDIN A,
HOPKINSON A,
DUA HS
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.6321.x
Subject(s) - rnase p , biology , mapk/erk pathway , ribonuclease , kinase , microbiology and biotechnology , pi3k/akt/mtor pathway , signal transduction , gene expression , messenger rna , rna , gene , biochemistry
Purpose Antimicrobial peptides are known to play an essential role in the host defense system. It was recently identified that the Ribonuclease(RNase)‐7 posses a broad‐spectrum microbicidal property against various pathogens.In this study our aims were a)to investigate the RNase‐7 expression in ocular inflammation and/or infection and b)to identify the involvement of possible signalling pathways in interleukin(IL)1‐beta mediated RNase‐7 expression using SV40‐immortalised human corneal epithelial cell line(SHCEL). Methods a)Total RNA was obtained from impression cytology specimen of normals and diseased individuals. Quantitative polymerase chain reaction technique was used to analyze RNase‐7 mRNA expression. b)SHCELs were treated with IL‐1beta and inhibitors of signalling molecules both in time‐ and dose‐dependent manner.Quantitation of both phosphorylated and total proteins was evaluated using Western blotting. The effect of IL‐1beta and inhibitors on secretory cytokines in SHCELs was measured using BD‐cytometric bead arrays. Results The normalised expression of RNase‐7 mRNA significantly increased in disease conditions (bacterial, viral, dry‐eye and acanthamoeba keratitis). Inhibition of following signalling pathways: PI3K(phosphatidylinositol‐3‐kinase), MAPK(mitogen‐activated protein kinase) and NF‐kB(nuclear factor‐kB) have reduced the RNase‐7 gene expression. Significant changes in the secreted cytokines (IL‐6, ‐8, ‐10 and‐12p70) was also demonstrated. Conclusion The first study which demonstrates the RNase‐7 expression in the eye. The involvement of multiple signalling pathways in RNase‐7 induction by IL‐1beta may facilitate the development of novel approaches in enhancing antimicrobial defense and healing of the eye.