Abstract
In response to ionizing radiation-induced injury, the normally quiescent intestinal stem cells marked by BMI1 participate in the regenerative response. Previously, we established a protective role for Krüppel-like factor 4 (KLF4) in the intestinal epithelium where it reduces senescence, apoptosis, and crypt atrophy following γ-radiation-induced gut injury. We also described a pro-proliferative function for KLF4 during the regenerative phase post irradiation. In the current study, using a mouse model in which Klf4 is deleted from quiescent BMI1(+) intestinal stem cells, we observed increased proliferation from the BMI1(+) lineage during homeostasis. In contrast, following irradiation, Bmi1-specific Klf4 deletion leads to decreased expansion of the BMI1(+) lineage due to a combination of reduced proliferation and increased apoptosis. Our results support a critical role for KLF4 in modulating BMI1(+) intestinal stem cell fate in both homeostasis and the regenerative response to radiation injury.
Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
MeSH terms
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Animals
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Apoptosis / radiation effects
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Cell Count
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Cell Proliferation / radiation effects
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Gamma Rays
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Gene Deletion
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Gene Expression Regulation
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Genes, Reporter
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Intestinal Mucosa / metabolism
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Intestines / cytology
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Intestines / radiation effects*
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Kruppel-Like Factor 4
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Kruppel-Like Transcription Factors / deficiency
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Kruppel-Like Transcription Factors / genetics*
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Luminescent Proteins / genetics
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Luminescent Proteins / metabolism
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Mice
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Mice, Transgenic
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Polycomb Repressive Complex 1 / genetics*
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Polycomb Repressive Complex 1 / metabolism
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Proto-Oncogene Proteins / genetics*
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Proto-Oncogene Proteins / metabolism
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Radiation Injuries / genetics
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Radiation Injuries / metabolism
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Radiation Injuries / pathology
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Radiation Injuries / rehabilitation*
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Regeneration / genetics
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Signal Transduction
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Stem Cells / cytology
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Stem Cells / metabolism
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Stem Cells / radiation effects*
Substances
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Bacterial Proteins
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Bmi1 protein, mouse
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Klf4 protein, mouse
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Kruppel-Like Factor 4
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Kruppel-Like Transcription Factors
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Luminescent Proteins
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Proto-Oncogene Proteins
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yellow fluorescent protein, Bacteria
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Polycomb Repressive Complex 1