Production and gene expression of IL-8-like cytokine GRO/CINC-1 in rat nasal mucosa

Growth-regulated gene product/cytokine-induced neutrophil chemoattractant (GRO/CINC)-1 is a rat chemokine with structural and functional homology to human IL-8. Chemokines are a family of cytokines whose participation in nasal inflammation in vivo remains to be established Using ELISA and RT-PCR, we investigated the production and gene expression of GRO/CINC-1 in rat nasal lavage and mucosa in vivo. GRO/CINC-1 in nasal lavage was produced by stimulation of LPS, ConA and IL1-beta. GRO/CINC-1 showed time- and dose-dependent production under all stimulants, but was more slowly induced by IL-1 beta. The steady-peak of the GRO/CINC-1 production remained at 3 h with LPS or ConA exposure, whereas it lasted 4 h or more after IL-1 beta exposure. At the time of peak production of GRO/CINC-1, we found that mRNA for the GRO/CINC-1 was induced in the nasal mucosa. The mRNA of the related inflammatory cytokines TNF-alpha and IFN-gamma were also expressed in nasal mucosa with stimulation of these reagents. Thus, this study revealed that exposure to bacterial endotoxin, mitogenic reagent and also IL-1 beta induced the production and gene expression of the neutrophil chemoattractant GRO/CINC-1 in rat nasal mucosa in vivo. This investigation of the characteristics of IL-8 family in nasal mucosa using rat models has extended the functional concept of cytokines in the inflammatory condition of nasal cavity in humans.