Gfi1-expressing Paneth cells revert to stem cells following intestinal injury
BackgroundAimChemotherapy drugs harm rapidly dividing normal healthy cells such as those lining the gastrointestinal tract, causing morbidity and mortality that complicates medical treatment modalities. Growth Factor-Independent 1 (GFI1) is a zinc finger transcriptional repressor implicated in the differentiation of secretory precursors into Paneth and goblet cells in the intestinal epithelium. We hypothesize that stimulating the reversion of Gfi1+ secretory cells into stem cells will improve intestinal epithelial regeneration and mitigate injury.\n\nMethodsGfi1 reporter mice (Gfi1cre/+; ROSA26 LSL-YFP) were treated with Doxorubicin, radiation, anti-CD3 antibody, and rotavirus to induce intestinal injury. Mice and intestinal organoids (enteroids) were used to investigate cellular repair mechanisms following injury.\n\nResultsUnder homeostatic conditions, Gfi1-lineage cells are Paneth and goblet cells, which were non-proliferative and not part of the stem cell pool. After injury, Gfi1+ secretory cells can re-enter the cell cycle and give rise to all cell lineages of the intestinal epithelium including stem cells. Reversion of Gfi1-lineage cells was observed in other injury model systems, including irradiation and anti-CD3 treatment, but not in ISC-sparing rotavirus infection. Our results also demonstrated that PI3kinase/AKT activation improved cell survival, and elevated WNT signaling increased the efficiency of Gfi1+ cell reversion upon injury.\n\nConclusionsThese findings indicate that Gfi1+ secretory cells display plasticity and reacquire stemness following severe damage. Moreover, PI3kinase/AKT and WNT are key regulators involved in injury-induced regeneration. Our studies identified potential therapeutic intervention strategies to mitigate the adverse effects of chemotherapy-induced damage to normal tissues and improve the overall effectiveness of cancer chemotherapy.