Abstract
Objective: Defects in Fas-mediated apoptosis are supposed to contribute to the accumulation of T lymphocytes in the gut of patients with Crohn's disease (CD). This phenomenon has been functionally linked with the elevated expression of Flip, an inhibitor of Fas-mediated apoptosis. In this study, the molecular mechanisms that control Flip in CD were examined. Methods: Paired colonic biopsies of patients with CD, patients with ulcerative colitis (UC) and normal controls were analysed for Flip by real-time PCR and western blotting. Flip was also evaluated in CD3+ lamina propria lymphocytes (T-LPLs) cultured with tosyl phenylalanyl chloromethyl ketone (TPCK; a nuclear factor-κB (NF-κB) inhibitor), AG490 (a Janus kinase 2 (Jak2)/signal transducer and activator of transcription (Stat) inhibitor) or 17-desmethoxy-17-N,N- dimethylamino-geldanamycin (DMAG; an inhibitor of heat shock protein 90). The rate of apoptosis was examined by flow cytometry. Results: In CD, upregulation of Flip occurred at both the RNA and protein level. Treatment of CD CD3 + T-LPLs with TPCK or AG490 markedly reduced Flip RNA, suggesting a role for NF-κB and Jak/Stat pathways in the transcriptional control of Flip in this condition. Consistently, both TPCK and AG490 sensitised CD T-LPLs to Fas-mediated apoptosis. Flip protein in cells from normal gut was rapidly degraded by the proteasome pathway. In contrast, in inflamed gut of both CD and UC patients, there was a reduced degradation of Flip via the ubiquitin-proteasome-dependent pathway, but Flip expression can be decreased by DMAG. Conclusions: The data demonstrate that Flip is regulated at both the transcriptional and post-translational level in CD, and indicate that in the normal but not inflamed gut Flip is degraded via the ubiquitin-proteasome- dependent pathway.
| Original language | English |
|---|---|
| Pages (from-to) | 1674-1680 |
| Number of pages | 7 |
| Journal | Gut |
| Volume | 57 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2008 |
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ASJC Scopus subject areas
- Gastroenterology
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Transcriptional and post-translational regulation of Flip, an inhibitor of Fas-mediated apoptosis, in human gut inflammation. / Caprioli, F.; Stolfi, C.; Caruso, R.; Fina, D.; Sica, G.; Biancone, L.; Pallone, F.; Monteleone, G.
In: Gut, Vol. 57, No. 12, 12.2008, p. 1674-1680.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transcriptional and post-translational regulation of Flip, an inhibitor of Fas-mediated apoptosis, in human gut inflammation
AU - Caprioli, F.
AU - Stolfi, C.
AU - Caruso, R.
AU - Fina, D.
AU - Sica, G.
AU - Biancone, L.
AU - Pallone, F.
AU - Monteleone, G.
PY - 2008/12
Y1 - 2008/12
N2 - Objective: Defects in Fas-mediated apoptosis are supposed to contribute to the accumulation of T lymphocytes in the gut of patients with Crohn's disease (CD). This phenomenon has been functionally linked with the elevated expression of Flip, an inhibitor of Fas-mediated apoptosis. In this study, the molecular mechanisms that control Flip in CD were examined. Methods: Paired colonic biopsies of patients with CD, patients with ulcerative colitis (UC) and normal controls were analysed for Flip by real-time PCR and western blotting. Flip was also evaluated in CD3+ lamina propria lymphocytes (T-LPLs) cultured with tosyl phenylalanyl chloromethyl ketone (TPCK; a nuclear factor-κB (NF-κB) inhibitor), AG490 (a Janus kinase 2 (Jak2)/signal transducer and activator of transcription (Stat) inhibitor) or 17-desmethoxy-17-N,N- dimethylamino-geldanamycin (DMAG; an inhibitor of heat shock protein 90). The rate of apoptosis was examined by flow cytometry. Results: In CD, upregulation of Flip occurred at both the RNA and protein level. Treatment of CD CD3 + T-LPLs with TPCK or AG490 markedly reduced Flip RNA, suggesting a role for NF-κB and Jak/Stat pathways in the transcriptional control of Flip in this condition. Consistently, both TPCK and AG490 sensitised CD T-LPLs to Fas-mediated apoptosis. Flip protein in cells from normal gut was rapidly degraded by the proteasome pathway. In contrast, in inflamed gut of both CD and UC patients, there was a reduced degradation of Flip via the ubiquitin-proteasome-dependent pathway, but Flip expression can be decreased by DMAG. Conclusions: The data demonstrate that Flip is regulated at both the transcriptional and post-translational level in CD, and indicate that in the normal but not inflamed gut Flip is degraded via the ubiquitin-proteasome- dependent pathway.
AB - Objective: Defects in Fas-mediated apoptosis are supposed to contribute to the accumulation of T lymphocytes in the gut of patients with Crohn's disease (CD). This phenomenon has been functionally linked with the elevated expression of Flip, an inhibitor of Fas-mediated apoptosis. In this study, the molecular mechanisms that control Flip in CD were examined. Methods: Paired colonic biopsies of patients with CD, patients with ulcerative colitis (UC) and normal controls were analysed for Flip by real-time PCR and western blotting. Flip was also evaluated in CD3+ lamina propria lymphocytes (T-LPLs) cultured with tosyl phenylalanyl chloromethyl ketone (TPCK; a nuclear factor-κB (NF-κB) inhibitor), AG490 (a Janus kinase 2 (Jak2)/signal transducer and activator of transcription (Stat) inhibitor) or 17-desmethoxy-17-N,N- dimethylamino-geldanamycin (DMAG; an inhibitor of heat shock protein 90). The rate of apoptosis was examined by flow cytometry. Results: In CD, upregulation of Flip occurred at both the RNA and protein level. Treatment of CD CD3 + T-LPLs with TPCK or AG490 markedly reduced Flip RNA, suggesting a role for NF-κB and Jak/Stat pathways in the transcriptional control of Flip in this condition. Consistently, both TPCK and AG490 sensitised CD T-LPLs to Fas-mediated apoptosis. Flip protein in cells from normal gut was rapidly degraded by the proteasome pathway. In contrast, in inflamed gut of both CD and UC patients, there was a reduced degradation of Flip via the ubiquitin-proteasome-dependent pathway, but Flip expression can be decreased by DMAG. Conclusions: The data demonstrate that Flip is regulated at both the transcriptional and post-translational level in CD, and indicate that in the normal but not inflamed gut Flip is degraded via the ubiquitin-proteasome- dependent pathway.
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U2 - 10.1136/gut.2008.149286
DO - 10.1136/gut.2008.149286
M3 - Article
VL - 57
SP - 1674
EP - 1680
JO - Gut
JF - Gut
SN - 0017-5749
IS - 12
ER -