ISSN:
1365-2036
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Tumour necrosis factor (TNF-α) is a candidate factor for involvement in inflammation-mediated gastric mucosal injury. However, the effect of this cytokine on gastric epithelial cells has been poorly investigated. In the present study, we examined whether gastric epithelial cells are resistant to TNF- α-induced apoptosis, and whether this resistance is related to ubiquitin-proteasome-associated nuclear factor-κB (NF-κB) activation.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:The rat gastric mucosal cell line RGM-1 was grown in DMEM/F12 medium supplemented with 10% FCS. Confluent monolayers of cells were pretreated or not for 60 min with PSI, a peptide aldehyde known to specifically inhibit the chymotrypsin-like activity of 26S proteasome. Cells were subsequently stimulated with recombinant rat TNF-α and their viability was determined by WST-1 assay. Apoptosis was confirmed by fluorescence microscopy after staining with Hoechst 33342 and propidium iodide, and DNA fragmentation was determined by flow cytometry using an APO-BRDU kit. IκB-α and the p65 binding subunit of NF-κB were detected by Western blots.〈section xml:id="abs1-3"〉〈title type="main"〉Results:Twenty-four-hour incubation with TNF-α alone or PSI alone did not affect the cell viability of RGM-1 cells. Pretreatment with PSI significantly enhanced the level of apoptosis induced by TNF-α. In RGM-1 cells treated with TNF-α, cytoplasmic IκB-α decreased and p65 in nuclear extracts increased markedly 30 min after cytokine stimulation. Pretreatment with PSI at 12.5 μmol/L blocked these TNF-α-induced changes.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion:PSI enhances TNF-α-induced apoptosis through inhibition of NF-κB activation in RGM-1 cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2036.16.s2.30.x
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