Abstract
BackgroundIntestinal mucositis is one of the major troublesome side effects of anticancer chemotherapy leading to poor patient compliance. In this study we addressed the role of the novel apolipoprotein E (ApoE) COG 133 mimetic peptide in 5-fluorouracil (5-FU)-challenged Swiss mice and IEC-6 cell monolayers. Experiments were also conducted in C57BL6J ApoE knock-out mice to assess the effects of apoE peptide treatment.MethodsExperimental groups were as follows: unchallenged controls, 5-FU-challenged mice (450 mg/kg, i.p) with or without the ApoE peptide (0.3, 1, and 3 μM, given twice daily i.p. for 4 days). Mice were sacrificed 3 days after 5-FU challenge. Proximal small intestinal samples were harvested for molecular biology and histological processing. We conducted ELISA assays and RT-PCR to target IL-1β, TNF-α, IL-10, iNOS, and myeloperoxidase (MPO) to assess intestinal inflammation. Cell death and NF-κB assays were also conducted in apoE knock-out mice. In our in vitro models, IEC-6 cells were exposed to 1 mM of 5-FU in glutamine free media with or without the ApoE peptide (0.02, 0.2, 2, 5, 10, and 20 μM). We investigated IEC-6 cell proliferation and migration, 24 h after the 5-FU challenge. Additionally, apoptotic IEC-6 cells were measured by Tunel and flow cytometry. Equimolar doses of the ApoA-I (D4-F) peptide were also used in some experiments for comparative studies.ResultsVillus blunting and heavy inflammatory infiltrates were seen in the 5-FU-challenged group, findings that were partially ameliorated by the ApoE peptide. We found increased intestinal MPO and pro-inflammatory IL-1β and TNF-α levels, and TNF-α and iNOS transcripts, and reduction of IL-10 following 5-FU treatment, each of which were partially abrogated by the peptide. Improvements were also found in IEC-6 cell apoptosis and migration following ApoE and D-4F treatment.ConclusionAltogether, these findings suggest that the novel ApoE COG 133 mimetic peptide can reduce 5-FU-induced intestinal changes and potentially benefit mucositis.
Highlights
Intestinal mucositis is one of the major troublesome side effects of anticancer chemotherapy leading to poor patient compliance
Chemotherapy cytotoxic effects vary in severity according to therapy schemes and patient susceptibility, many of them may lead to intestinal mucosal damage, heavy inflammatory responses, often associated with increased epithelial cell death, intestinal epithelial breakdown, and luminal bacterial translocation [2,3]
apolipoprotein E (ApoE) COG 133 mimetic peptide treatment (0.3, 1 and 3 μM) did not improve weight loss caused by the high 5FU dose used in our protocols in either Swiss mice or ApoE knock-out mice. 5-FU-challenged mice exhibited marked reductions (77.1%) in the leukocyte count, compared to the unchallenged control group (p < 0.001), confirming that the 5-FU-tested dose was cytotoxic to the bone marrow, and this effect was not diminished by the ApoE COG 133 peptide administration (p > 0.05, by ANOVA), a trend of increased leukocyte counts was seen
Summary
Intestinal mucositis is one of the major troublesome side effects of anticancer chemotherapy leading to poor patient compliance. In this study we addressed the role of the novel apolipoprotein E (ApoE) COG 133 mimetic peptide in 5-fluorouracil (5-FU)-challenged Swiss mice and IEC-6 cell monolayers. Mucositis is a side effect of chemotherapy in which there is a dramatic drop in quality of life of patients, sometimes leading to discontinuation of therapy. Chemotherapy cytotoxic effects vary in severity according to therapy schemes and patient susceptibility, many of them may lead to intestinal mucosal damage, heavy inflammatory responses, often associated with increased epithelial cell death, intestinal epithelial breakdown, and luminal bacterial translocation [2,3]. Intestinal mucositis with diarrhea and vomiting is often the doselimiting adverse effect of 5-FU therapy and is likely accompanied by poor treatment compliance. In vitro studies with IEC-6 monolayers exposed to 5-FU and under glutamine supplementation confirmed a promitotic activity of these gut-trophic nutrients [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
