title: Nipple connective tissue and its development: insights from the K14-PTHrP mouse.
abstract: Parathyroid hormone-related protein (PTHrP) regulates a wide variety of developmental processes. Keratin 14 (K14) promoter-mediated overexpression of PTHrP in the epidermis during development converts the entire murine ventral skin to hairless nipple-like skin. In this report, we characterize the morphology and processes that influence the development of nipple connective tissue. The connective tissue of the nipple displayed increased levels of proteoglycans, and collagen bundles with atypical morphology, as well as increased numbers of mast cells, capillaries, nerve fibers and dermal melanocytes. The unique characteristics of nipple connective tissue were not present until mice reach 3-4 weeks of age. The adult male K14-PTHrP mouse has a less dramatic ventral skin phenotype, and does not manifest a nipple-like dermis. Ovariectomy or orchiedectomy prior to sexual maturity had no impact on the ventral skin of the male or female K14-PTHrP mice, but exposure to androgens in utero repressed many of the nipple-like characteristics in the ventral skin of the female K14-PTHrP mice.
authors.affiliation: Medical Sciences, Indiana University School of Medicine, Bloomington, IN 47405-4401, USA.
authors.forename: Arman
authors.initials: A
authors.lastname: Abdalkhani
authors.forename: Rani
authors.initials: R
authors.lastname: Sellers
authors.forename: Justin
authors.initials: J
authors.lastname: Gent
authors.forename: Heather
authors.initials: H
authors.lastname: Wulitich
authors.forename: Sue
authors.initials: S
authors.lastname: Childress
authors.forename: Barry
authors.initials: B
authors.lastname: Stein
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Boissy
authors.forename: John J
authors.initials: JJ
authors.lastname: Wysolmerski
authors.forename: John
authors.initials: J
authors.lastname: Foley
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D003238:Connective Tissue / Q000473:pathology*; D005109:Extracellular Matrix / Q000378:metabolism / Q000473:pathology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D053547:Keratin-14; D007633:Keratins / Q000235:genetics / Q000502:physiology*; D008297:Male; D051379:Mice; D044162:Parathyroid Hormone-Related Protein; D036361:Peptide Hormones / Q000235:genetics / Q000502:physiology*; D012867:Skin / Q000166:cytology*; D013256:Steroids / Q000378:metabolism
chemical_list: D012739:Gonadal Steroid Hormones; D053547:Keratin-14; C507446:Krt14 protein, mouse; D044162:Parathyroid Hormone-Related Protein; D036361:Peptide Hormones; D013256:Steroids; D007633:Keratins