Genome Toxicity and Impaired Stem Cell Function after Conditional Activation of CreERT2 in the Intestine.
With the tamoxifen-inducible CreERT2 system, genetic recombination can be temporally controlled in a cell-type-specific manner in intact animals, permitting dissection of the molecular underpinnings of mammalian physiology. Here we present a significant drawback to CreERT2 technology for analysis of intestinal stem cells. Using the intestine-specific Villin-CreERT2 mouse strain, we observed delayed intestinal regeneration post irradiation. Villin-CreERT2 activation was associated with DNA damage and cryptic loxP site cleavage. Analysis of stem cell-specific CreERT2 strains showed that the genome toxicity impairs function of crypt base columnar stem cells, resulting in loss of organoid initiating activity. Importantly, the stem cell impairment is short-lived, with return to normal by 7 days post tamoxifen treatment. Our findings demonstrate that mouse genetic experiments that utilize CreERT2 should consider the confounding effects of enhanced stem cell sensitivity to genome toxicity resulting from CreERT2 activation.
['Bohin|Natacha|N|', 'Carlson|Elizabeth A|EA|', 'Samuelson|Linda C|LC|']
D000818:Animals D053837:DNA Cleavage D016678:Genome D019426:Integrases D007422:Intestines D008810:Mice, Inbred C57BL D008840:Microfilament Proteins D009940:Organoids D011960:Receptors, Estrogen D012038:Regeneration D013234:Stem Cells D013629:Tamoxifen
CreERT2 intestinal stem cell mouse loxP organoid tamoxifen crypt regeneration genotoxicity