KLF4 Regulates Goblet Cell Differentiation in BMI1 Reserve Intestinal Stem Cell Lineage during Homeostasis

Int J Stem Cells. 2020 Nov 30;13(3):424-431. doi: 10.15283/ijsc20048.

Abstract

Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor, expressed in villus cells of the intestinal epithelium, that promotes cellular differentiation and tissue homeostasis. Previous studies suggest that BMI1 cells represent secretory progenitors with reserve intestinal stem cell (rISC) activity. However, it has not been elucidated how KLF4 contributes to crypt regeneration originated from BMI1 rISC lineage during homeostasis. In this study, Bmi1-CreER;Rosa26eYFP (Bmi1Ctrl) and Bmi1-CreER;Rosa26eYFP;Klf4fl/fl (Bmi1ΔKlf4) mice were injected with tamoxifen to label BMI1 cells and their lineage and to delete Klf4. During homeostasis, MUC2 goblet cells appeared in the BMI1 cell lineage 2, 3 and 7 days after tamoxifen administration. After Klf4 deletion in BMI1 cells, the number of KLF4 and MUC2 cells in eYFP cells decreased in Bmi1ΔKlf4 mice compared with Bmi1Ctrl mice. Thus, KLF4 was positively correlated with goblet cell differentiation in BMI1 cell derived lineage. In ex-vivo analysis, organoids derived from single eYFP cells of Bmi1Ctrl mice contained MUC2-expressing cells that co-expressed KLF4. On the other hand, organoids derived from Klf4-deleted eYFP cells from Bmi1ΔKlf4 mice showed reduced number of MUC2-expressing cells. In conclusion, these results suggest that KLF4 regulates goblet cell differentiation in BMI1 ISC-derived lineage during homeostasis.

Keywords: Goblet cell; Intestinal stem cell; Krüppel-like factor 4; Mucin 2.