Transmural pressure induces IL-6 secretion by intestinal epithelial cells.
Although intestinal epithelial cells (IECs) are known as an important source for IL-6, it is not known whether mechanical forces affect IL-6 production. We investigated how transmural pressure modulates IL-6 synthesis and activation of transcription factors in IECs. Pressure was loaded onto IEC-18 cells by introducing compressed helium gas into the cell culture flask for 1-48 h. IL-6 release into the culture media was determined by cell proliferation bioassay using an IL-6-dependent mouse hybridoma cell line (7TD1). Exposure to pressure (80 mmHg) significantly enhanced IL-6 release into the culture media from IEC-18 cells at 12 h. Under control conditions, IL-6 secretion was directed to the basolateral side, but after exposure to pressure IL-6 secretion was increased in both the apical and basolateral sides. A nuclear factor kappa B (NF-kappaB) decoy reversed completely the pressure-induced increase of IL-6 secretion by IEC-18 cells. Pressure treatment enhanced IL-6 mRNA expression in IECs within 6 h. Pressure loading significantly enhanced the activation of both NF-kappaB and NF-IL-6 from 1h in the nuclear protein of IEC-18 cells as assessed by the electrophoretic mobility shift assay using FITC-conjugated specific primers. Increased phosphorylation of I-kappa B was also demonstrated in the cytosol of IEC cells within 1h by Western blot analysis. These results suggest a possible role for pressure loading in immune modulation of the intestinal mucosa by the stimulation of IL-6 release from intestinal epithelial cells.
Kishikawa
H
H
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
Miura
S
S
Yoshida
H
H
Hirokawa
M
M
Nakamizo
H
H
Higuchi
H
H
Adachi
M
M
Nakatsumi
R C
RC
Suzuki
H
H
Saito
H
H
Ishii
H
H
D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D002460:Cell Line / Q000378:metabolism; D016764:Cell Polarity; D004268:DNA-Binding Proteins / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004847:Epithelial Cells / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D020672:I-kappa B Proteins; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D011312:Pressure; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D013314:Stress, Mechanical; D013997:Time Factors; D014158:Transcription, Genetic
D022782:CCAAT-Enhancer-Binding Protein-beta; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D015850:Interleukin-6; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; C000606206:Nfkbia protein, rat; D012333:RNA, Messenger; D000072000:NF-KappaB Inhibitor alpha