Regeneration of intestinal stem/progenitor cells following doxorubicin treatment of mice.
The intestinal epithelium is in a constant state of renewal. The rapid turnover of cells is fed by a hierarchy of transit amplifying and stem/progenitor cells destined to give rise to the four differentiated epithelial lineages of the small intestine. Doxorubicin (Dox) is a commonly used chemotherapeutic agent that preferentially induces apoptosis in the intestinal stem cell zone (SCZ). We hypothesized that Dox treatment would initially decrease "+4" intestinal stem cell numbers with a subsequent expansion during mucosal repair. Temporal assessment following Dox treatment demonstrated rapid induction of apoptosis in the SCZ leading to a decrease in the number of intestinal stem/progenitor cells as determined by flow cytometry for CD45(-) SP cells, and immunohistochemistry of cells positive for putative +4 stem cell markers beta-cat(Ser552) and DCAMKL1. Between 96 and 168 h postinjection, overall proliferation in the crypts increased concomitant with increases in both absolute and relative numbers of goblet, Paneth, and enteroendocrine cells. This regeneration phase was also associated with increases of CD45(-) SP cells, beta-cat(Ser552)-positive cells, crypt fission, and crypt number. We used Lgr5-lacZ mice to assess behavior of Lgr5-positive stem cells following Dox and found no change in this cell population. Lgr5 mRNA level was also measured and showed no change immediately after Dox but decreased during the regeneration phase. Together these data suggest that, following Dox-induced injury, expansion of intestinal stem cells occurs during mucosal repair. On the basis of available markers this expansion appears to be predominantly the +4 stem cell population rather than those of the crypt base.
Dekaney
Christopher M
CM
Department of Surgery, The University of North Carolina, Chapel Hill, North Carolina 27599-7223, USA. dekaney@med.unc.edu
Gulati
Ajay S
AS
Garrison
Aaron P
AP
Helmrath
Michael A
MA
Henning
Susan J
SJ
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects*; D019070:Cell Lineage; D049109:Cell Proliferation / Q000187:drug effects*; D000089742:Doublecortin-Like Kinases; D004317:Doxorubicin / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D007274:Injections, Intraperitoneal; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007583:Jejunum / Q000187:drug effects / Q000473:pathology; D017493:Leukocyte Common Antigens / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D012038:Regeneration / Q000187:drug effects*; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D051176:beta Catenin / Q000378:metabolism
D000903:Antibiotics, Antineoplastic; C495267:CTNNB1 protein, mouse; C493597:Lgr5 protein, mouse; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D051176:beta Catenin; D004317:Doxorubicin; D000089742:Doublecortin-Like Kinases; C485525:Dclk1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D017493:Leukocyte Common Antigens; C516770:Ptprc protein, mouse