In this study we have first analyzed by microarray and RT-qPCR the miR-profile of cystic fibrosis IB3-1 cells infected with Pseudomonas aeruginosa, demonstrating miR-93 as highly expressed and reduced during infection, in association with increased expression of the IL-8 gene. Sequence analysis shows that the 3’UTR region of the IL-8 mRNA is a potential target of miR-93 and highly conserved throughout molecular evolution. The involvement of miR-93 in IL-8 gene expression was demonstrated by the finding that down-modulation of miR-93 following P.aeruginosa infection was counteracted by pre-miR-93 transfection. In addition, in uninfected IB3-1 cells treated with antagomiR-93, IL-8 was up-regulated. Since miR-93 is located in the 13th intron of the gene of MCM7 (minichromosome maintenance protein 7), the expression of MCM7 gene was studied in parallel with miR-93 and the miR-93 target IL-8 mRNA. After P.aeruginosa infection, a decrease of both MCM7 and miR-93 transcripts occurs in parallel with increase of IL-8 production. The decrease of MCM7/miR-93 transcription was associated with decrease of nuclear recruitment of MYC and E2F-1 transcription factors, involved in the regulation of the MCM7 gene promoter. To our knowledge, this is the first observation of a possible link between micro RNA expression and IL-8 induction in cystic fibrosis cells infected by Pseudomonas aeruginosa. The results reported in the present paper, therefore, suggest that in addition to transcriptional NF-kB dependent up-regulation of IL-8 gene expression, IL-8 protein secretion might depend from interactions of the IL-8 mRNA with inhibitory micro RNAs, including miR-93.
Expression of miR-93 and IL-8 during Pseudomonas aeruginosa infection of the human bronchial cystic fibrosis IB3-1 cells
FABBRI, Enrica;BORGATTI, Monica;BIANCHI, Nicoletta;FINOTTI, Alessia;MONTAGNER, Giulia;LAMPRONTI, Ilaria;GAMBARI, Roberto
2013
Abstract
In this study we have first analyzed by microarray and RT-qPCR the miR-profile of cystic fibrosis IB3-1 cells infected with Pseudomonas aeruginosa, demonstrating miR-93 as highly expressed and reduced during infection, in association with increased expression of the IL-8 gene. Sequence analysis shows that the 3’UTR region of the IL-8 mRNA is a potential target of miR-93 and highly conserved throughout molecular evolution. The involvement of miR-93 in IL-8 gene expression was demonstrated by the finding that down-modulation of miR-93 following P.aeruginosa infection was counteracted by pre-miR-93 transfection. In addition, in uninfected IB3-1 cells treated with antagomiR-93, IL-8 was up-regulated. Since miR-93 is located in the 13th intron of the gene of MCM7 (minichromosome maintenance protein 7), the expression of MCM7 gene was studied in parallel with miR-93 and the miR-93 target IL-8 mRNA. After P.aeruginosa infection, a decrease of both MCM7 and miR-93 transcripts occurs in parallel with increase of IL-8 production. The decrease of MCM7/miR-93 transcription was associated with decrease of nuclear recruitment of MYC and E2F-1 transcription factors, involved in the regulation of the MCM7 gene promoter. To our knowledge, this is the first observation of a possible link between micro RNA expression and IL-8 induction in cystic fibrosis cells infected by Pseudomonas aeruginosa. The results reported in the present paper, therefore, suggest that in addition to transcriptional NF-kB dependent up-regulation of IL-8 gene expression, IL-8 protein secretion might depend from interactions of the IL-8 mRNA with inhibitory micro RNAs, including miR-93.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
