title: Microvesicle-mediated Wnt/β-Catenin Signaling Promotes Interspecies Mammary Stem/Progenitor Cell Growth.
abstract: Signaling mechanisms that regulate mammary stem/progenitor cell (MaSC) self-renewal are essential for developmental changes that occur in the mammary gland during pregnancy, lactation, and involution. We observed that equine MaSCs (eMaSCs) maintain their growth potential in culture for an indefinite period, whereas canine MaSCs (cMaSCs) lose their growth potential in long term cultures. We then used this system to investigate the role of microvesicles (MVs) in promoting self-renewal properties. We found that Wnt3a and Wnt1 were expressed at higher levels in MVs isolated from eMaSCs compared with those from cMaSCs. Furthermore, eMaSC-MVs were able to induce Wnt/β-catenin signaling in different target cells, including cMaSCs. Interestingly, the induction of Wnt/β-catenin signaling in cMaSCs was prolonged when using eMaSC-MVs compared with recombinant Wnt proteins, indicating that MVs are not only important for transport of Wnt proteins, but they also enhance their signaling activity. Finally, we demonstrate that the eMaSC-MVs-mediated activation of the Wnt/β-catenin signaling pathway in cMaSCs significantly improves the ability of cMaSCs to grow as mammospheres and, importantly, that this effect is abolished when eMaSC-MVs are treated with Wnt ligand inhibitors. This suggests that this novel form of intercellular communication plays an important role in self-renewal.
authors.affiliation: From the Baker Institute for Animal Health and.
authors.forename: Leen
authors.initials: L
authors.lastname: Bussche
authors.affiliation: From the Baker Institute for Animal Health and.
authors.forename: Gat
authors.initials: G
authors.lastname: Rauner
authors.affiliation: Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853 and.
authors.forename: Marc
authors.initials: M
authors.lastname: Antonyak
authors.affiliation: From the Baker Institute for Animal Health and.
authors.forename: Bethany
authors.initials: B
authors.lastname: Syracuse
authors.affiliation: From the Baker Institute for Animal Health and.
authors.forename: Melissa
authors.initials: M
authors.lastname: McDowell
authors.affiliation: the Department of Cell & Developmental Biology, Weill Cornell Medical College, New York, New York 10065.
authors.forename: Anthony M C
authors.initials: AMC
authors.lastname: Brown
authors.affiliation: Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853 and.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Cerione
authors.affiliation: From the Baker Institute for Animal Health and. Electronic address: grv23@cornell.edu.
authors.forename: Gerlinde R
authors.initials: GR
authors.lastname: Van de Walle
mesh_terms: D000818:Animals; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D004285:Dogs; D005260:Female; D006736:Horses; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000502:physiology*; D051155:Wnt1 Protein / Q000378:metabolism*; D060509:Wnt3A Protein / Q000378:metabolism*
chemical_list: D051155:Wnt1 Protein; D060509:Wnt3A Protein
keywords: Wnt signaling; cell-cell interaction; extracellular vesicles; mammary gland; stem cells