title: Pelvic Organ Support in Animals with Partial Loss of Fibulin-5 in the Vaginal Wall.
abstract: Compromise of elastic fiber integrity in connective tissues of the pelvic floor is most likely acquired through aging, childbirth-associated injury, and genetic susceptibility. Mouse models of pelvic organ prolapse demonstrate systemic deficiencies in proteins that affect elastogenesis. Prolapse, however, does not occur until several months after birth and is thereby acquired with age or after parturition. To determine the impact of compromised levels of fibulin-5 (Fbln5) during adulthood on pelvic organ support after parturition and elastase-induced injury, tissue-specific conditional knockout (cKO) mice were generated in which doxycycline (dox) treatment results in deletion of Fbln5 in cells that utilize the smooth muscle α actin promoter-driven reverse tetracycline transactivator and tetracycline responsive element-Cre recombinase (i.e., Fbln5f/f/SMA++-rtTA/Cre+, cKO). Fbln5 was decreased significantly in the vagina of cKO mice compared with dox-treated wild type or controls (Fbln5f/f/SMA++-rtTA/Cre-/-). In controls, perineal body length (PBL) and bulge increased significantly after delivery but declined to baseline values within 6-8 weeks. Although overt prolapse did not occur in cKO animals, these transient increases in PBL postpartum were amplified and, unlike controls, parturition-induced increases in PBL (and bulge) did not recover to baseline but remained significantly increased for 12 wks. This lack of recovery from parturition was associated with increased MMP-9 and nondetectable levels of Fbln5 in the postpartum vagina. This predisposition to prolapse was accentuated by injection of elastase into the vaginal wall in which overt prolapse occurred in cKO animals, but rarely in controls. Taken together, our model system in which Fbln5 is conditionally knock-downed in stromal cells of the pelvic floor results in animals that undergo normal elastogenesis during development but lose Fbln5 as adults. The results indicate that vaginal fibulin-5 during development is crucial for baseline pelvic organ support and is also important for protection and recovery from parturition- and elastase-induced prolapse.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Chin
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Wieslander
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Haolin
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Sunil
authors.initials: S
authors.lastname: Balgobin
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: T Ignacio
authors.initials: TI
authors.lastname: Montoya
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yanagisawa
authors.affiliation: Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: R Ann
authors.initials: RA
authors.lastname: Word
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D004547:Elastic Tissue / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic / Q000378:metabolism; D023421:Models, Animal; D009130:Muscle, Smooth / Q000378:metabolism; D010196:Pancreatic Elastase / Q000378:metabolism; D036801:Parturition / Q000378:metabolism; D017773:Pelvic Floor / Q000502:physiology; D056887:Pelvic Organ Prolapse / Q000378:metabolism*; D049590:Postpartum Period / Q000378:metabolism; D011247:Pregnancy; D011994:Recombinant Proteins / Q000378:metabolism*; D014621:Vagina / Q000378:metabolism*
chemical_list: D000199:Actins; D016326:Extracellular Matrix Proteins; C120769:Fbln5 protein, mouse; D011994:Recombinant Proteins; D010196:Pancreatic Elastase; D020780:Matrix Metalloproteinase 9