title: Exploring the dynamics of progenitor cells in the urethra after simulated birth trauma in mice.
abstract: OBJECTIVE
  To examine the alteration in the cellular dynamics of the urethral tissue after a simulated birth trauma in a mouse model.
  
  
  METHODS
  A total of 36 B6 mice received vaginal distention treatment, and four untreated mice were used as controls. Specimens were collected every 24 hours after the injury for 9 consecutive days and examined using immunofluorescent staining for cell markers including c-kit, smooth muscle actin (SMA), and vimentin. Confocal microscopy was used to localize the stained cells and determine the cell number.
  
  
  RESULTS
  The number of c-kit positive cells increased after the 1stday and peaked on the 3rdday. The amount of SMA positive cells rapidly reduced to its lowest count on the 1stday and maintained a statistically significant low cell number than that at the basal level for 4 days after vaginal distension. The cell number finally returned to basal level on the 9thday. The amount of vimentin positive cells increased dramatically after the 1stday and plateaued from the 3rdday to the 9thday. The number of vimentin positive cells in the plateau phase was significantly higher than that of the control group.
  
  
  CONCLUSIONS
  Our study confirmed that the dynamic change in different cell types after the urethral injury was dependent on the nature and physiology of the wound repairing cells during the tissue healing process. It might be a simple animal model to study birth trauma repair; however, the varied progenitor cell activity in different species should also be considered.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei, Taiwan; Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Hung-Yen
authors.initials: HY
authors.lastname: Chin
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Li-Hsuan
authors.initials: LH
authors.lastname: Chiu
authors.affiliation: Department of Management Information Systems, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Kuan-Cheng
authors.initials: KC
authors.lastname: Lin
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
authors.forename: Chi-Hsin
authors.initials: CH
authors.lastname: Chiang
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital at Linkou, Tao-Yuan, Taiwan; College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan. Electronic address: wang2260@gmail.com.
authors.forename: Chin-Jung
authors.initials: CJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001720:Birth Injuries / Q000150:complications / Q000473:pathology*; D002452:Cell Count; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D011247:Pregnancy; D011270:Pregnancy, Animal; D013234:Stem Cells / Q000473:pathology*; D014521:Urethra / Q000473:pathology*; D014550:Urinary Incontinence, Stress / Q000209:etiology / Q000473:pathology*
keywords: pelvic floor; progenitor cells; trauma; urinary incontinence; wound healing