In vivo induction and regulation of interleukin-8-like chemokine GRO/CINC-1 in rat middle ear.
Interleukin-8 possesses chemotactic-activating properties toward neutrophils, and may contribute to the pathogenesis of middle ear inflammation. GRO/CINC-1 is a rat chemokine with structural and functional homology to human interleukin-8, the induction and regulation of which in the middle ear cavity in vivo remains to be established. The production of GRO/CINC-1 in middle ear lavage and gene expression in the middle mucosa was investigated using topical inoculation with lipopolysaccharide (LPS) in the rat in vivo model. GRO/CINC-1 in middle ear lavage showed time- and dose-dependent production under LPS stimulation. The peak of the GRO/CINC-1 production was reached by 4 h after LPS 1 h exposure, whereas the level of production subsequently returned to the level without LPS stimulation at 8 h after LPS stimulation. The topical corticosteroid perfusion in the middle ear after LPS stimulation significantly reduced the production of GRO/CINC-1 in the middle ear cavity compared with that without corticosteroid. At the time of peak production, the expression of GRO/CINC-1 mRNA, evaluated using the polymerase chain reaction, was considerable in the middle ear mucosa. This investigation of the characteristics of interleukin-8-like cytokine in the middle ear cavity using a rat in vivo model has extended the functional concept of chemokines at the initial stage in otitis media.
Yoshioka
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I
Department of Otolaryngology, Sapporo Medical University, School of Medicine, Japan.
Himi
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T
Kataura
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A
D000818:Animals; D054360:Chemokine CXCL1; D018925:Chemokines / Q000235:genetics / Q000378:metabolism*; D019743:Chemokines, CXC; D002630:Chemotactic Factors / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004432:Ear, Middle / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D006133:Growth Substances / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008297:Male; D010033:Otitis Media / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase; D051381:Rats; D017208:Rats, Wistar
C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D018925:Chemokines; D019743:Chemokines, CXC; D002630:Chemotactic Factors; C513297:Cxcl1 protein, rat; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase