title: Intestinal Epithelial Stem Cells: Distinct Behavior After Surgical Injury and Teduglutide Administration.
abstract: BACKGROUND
  Previous studies suggest that intestinal epithelial stem cells (IESC), critical drivers of homeostasis and regeneration, include two subpopulations: crypt-based columnar and "position +4" stem cells, identified by Lgr5 and Bmi1 biomarkers, respectively. Teduglutide is an enterotrophic counterpart of glucagon-like peptide 2. This study aimed to investigate the response of putative IESC to surgical injury and teduglutide administration on an animal model of intestinal resection and anastomosis.
  
  
  METHODS
  Wistar rats (n = 59) were distributed into four groups: "Ileal Resection" versus "Laparotomy", subsequently subdivided into "Postoperative Teduglutide Administration" versus "No Treatment"; and sacrificed at third or seventh days, with ileal sample harvesting. Flow cytometry was used to analyze epithelial stem cells with monoclonal antibodies against Lgr5, Bmi1 and also CD44, CD24, CD166, and Grp78 surface markers.
  
  
  RESULTS
  Surgical trauma induced an increase of epithelial stem cells population at third day (9.0 ± 0.3 versus 5.7 ± 0.3%, p = 0.0001), which was more intense and involved all subpopulations after ileal resection. At seventh day, teduglutide was significantly associated with higher proportion of Lgr5+/Bmi1-cells (5.8 ± 0.1 versus 2.9 ± 0.3%, p = 0.005) and, on the contrary, lower percentage of Lgr5-/Bmi1+cells (0.03 ± 0.01 versus 1.9 ± 0.1%, p = 0.049) after ileal resection; and higher proportion of Lgr5+/Bmi1+cells (1.7 ± 0.1 versus 1.1 ± 0.2%, p = 0.028) after isolated laparotomy. After surgery, Lgr5+/Bmi1-and Lgr5-/Bmi1+subpopulations demonstrated an inverse correlation and both correlated negatively with Grp78 labeling index. Lgr5-/Bmi1+and CD44+/CD24low/CD166+/Grp78+cells proportions exhibited a high grade positive correlation.
  
  
  CONCLUSIONS
  Those observations support the existence of two epithelial stem cells subpopulations with distinct behavior after surgical injury and teduglutide treatment.
authors.affiliation: a Department of Surgery A , Hospital da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, EPE , Coimbra , Portugal.|b University Clinic of Surgery , Faculty of Medicine, University of Coimbra , Coimbra , Portugal.
authors.forename: Beatriz P
authors.initials: BP
authors.lastname: Costa
authors.affiliation: c Laboratory of Oncobiology and Hematology, University Clinic of Hematology and Applied Molecular Biology Unit, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|e Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Gonçalves
authors.affiliation: d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|e Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|f Institute of Biophysics, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Abrantes
authors.affiliation: c Laboratory of Oncobiology and Hematology, University Clinic of Hematology and Applied Molecular Biology Unit, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|e Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Alves
authors.affiliation: d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|g Institute of Physiology, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Matafome
authors.affiliation: d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|g Institute of Physiology, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Seiça
authors.affiliation: c Laboratory of Oncobiology and Hematology, University Clinic of Hematology and Applied Molecular Biology Unit, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|e Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|h Department of Clinical Hematology , Coimbra University Hospital, Centro Hospitalar e Universitário de Coimbra, EPE , Coimbra , Portugal.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Sarmento-Ribeiro
authors.affiliation: d Center for Neuroscience and Cell Biology (CNC) and Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine , University of Medicine , Coimbra , Portugal.|e Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine , University of Coimbra , Coimbra , Portugal.|f Institute of Biophysics, Faculty of Medicine , University of Coimbra , Coimbra , Portugal.
authors.forename: M Filomena
authors.initials: MF
authors.lastname: Botelho
authors.affiliation: a Department of Surgery A , Hospital da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, EPE , Coimbra , Portugal.|b University Clinic of Surgery , Faculty of Medicine, University of Coimbra , Coimbra , Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Castro-Sousa
mesh_terms: D000714:Anastomosis, Surgical / Q000009:adverse effects*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D005434:Flow Cytometry; D053767:Glucagon-Like Peptide 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D007082:Ileum / Q000166:cytology / Q000502:physiology / Q000601:surgery; D007413:Intestinal Mucosa / Q000166:cytology* / Q000502:physiology / Q000601:surgery; D008297:Male; D023421:Models, Animal; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*
chemical_list: D015415:Biomarkers; D053767:Glucagon-Like Peptide 2; D010455:Peptides; C494910:teduglutide
keywords: Bmi1; Lgr5; flow cytometry; intestinal epithelial stem cells; intestinal resection; teduglutide