title: Elastic fiber assembly in the adult mouse pubic symphysis during pregnancy and postpartum.
abstract: Impairment of pelvic organ support has been described in mice with genetic modifications of the proteins involved in elastogenesis, such as lysyl oxidase-like 1 (LOXL1) and fibulin 5. During pregnancy, elastic fiber-enriched pelvic tissues are modified to allow safe delivery. In addition, the mouse pubic symphysis is remodeled in a hormone-controlled process that entails the modification of the fibrocartilage into an interpubic ligament (IpL) and the relaxation of this ligament. After first parturition, recovery occurs to ensure pelvic tissue homeostasis. Because ligaments are the main supports of the pelvic organs, this study aimed to evaluate elastogenesis in the IpL during mouse pregnancy and postpartum. Accordingly, virgin, pregnant, and postpartum C57BL/6 mice were studied using light, confocal, and transmission electron microscopy as well as Western blots and real-time PCR. Female mice exhibited the separation of the pubic bones and the formation, relaxation, and postpartum recovery of the IpL. By the time the IpL was formed, the elastic fibers had increased in profile length and diameter, and they consisted of small conglomerates of amorphous material distributed among the bundles of microfibrils. Our analyses also indicated that elastin/tropoelastin, fibrillin 1, LOXL1/Loxl1, and fibulin 5 were spatially and temporally regulated, suggesting that these molecules may contribute to the synthesis of new elastic fibers during IpL development. Overall, this work revealed that adult elastogenesis may be important to assure the elasticity of the pelvic girdle during preparation for parturition and postpartum recovery. This finding may contribute to our understanding of pathological processes involving elastogenesis in the reproductive tract.
authors.affiliation: Department of Histology and Embryology, State University of Campinas (Unicamp), Campinas, Brazil.
authors.forename: Sílvio Roberto
authors.initials: SR
authors.lastname: Consonni
authors.forename: Cláudio Chrysostomo
authors.initials: CC
authors.lastname: Werneck
authors.forename: Débora Rodrigues
authors.initials: DR
authors.lastname: Sobreira
authors.forename: Fabiana
authors.initials: F
authors.lastname: Kühne
authors.forename: Suzana Guimarães
authors.initials: SG
authors.lastname: Moraes
authors.forename: Lúcia Elvira
authors.initials: LE
authors.lastname: Alvares
authors.forename: Paulo Pinto
authors.initials: PP
authors.lastname: Joazeiro
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000818:Animals; D004547:Elastic Tissue / Q000166:cytology / Q000378:metabolism*; D004548:Elasticity; D004549:Elastin / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005260:Female; D000071838:Fibrillin-1; D000071837:Fibrillins; D008022:Ligaments / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000378:metabolism; D010388:Pelvis; D049590:Postpartum Period / Q000378:metabolism*; D011247:Pregnancy; D011631:Pubic Symphysis / Q000166:cytology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D054392:Adipokines
chemical_list: D000594:Amino Acid Oxidoreductases; D004549:Elastin; D016326:Extracellular Matrix Proteins; D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; D011994:Recombinant Proteins; C120769:Fbln5 protein, mouse; C000605724:Fbn1 protein, mouse; D054392:Adipokines; C482019:Loxl1 protein, mouse