Heparin affin regulatory peptide in milk: its involvement in mammary gland homeostasis.
HARP (heparin affin regulatory peptide) is a heparin binding growth factor implicated in cellular growth and differentiation. Previously, HARP had been localized in the human mammary, in both alveolar epithelial and myoepithelial cells although HARP mRNAs were only expressed by myoepithelial cells [J. Histochem. Cytochem. 45 (1997) 1]. In the present study, we demonstrate that HARP is secreted in human mature milk with concentrations ranging from 17.68+/-6.4ng/ml in mature milk to 59.9+/-11.22ng/ml in colostrum. In vitro, HARP was found to be mitogenic on human mammary epithelial and myoepithelial cell lines and correlated with the expression of its high affinity receptor tyrosine kinase ALK (anaplastic lymphoma kinase). In vivo, ALK is expressed in both mammary epithelial and myoepithelial cells, suggesting that HARP could act in vivo as a paracrine and autocrine growth factor in the regulation of the mammary gland development and its homeostatic maintenance during pregnancy and lactation.
Bernard-Pierrot
Isabelle
I
Laboratoire de Recherche sur la Croissance Cellulaire, la Réparation et la Régénération Tissulaires FRE CNRS No. 2412, Université Paris Val de Marne Avenue du Général de Gaulle, Créteil, France.
Delbé
Jean
J
Heroult
Melanie
M
Rosty
Christophe
C
Soulié
Patrick
P
Barritault
Denis
D
Milhiet
Pierre-Emmanuel
PE
Courty
Jose
J
D000077548:Anaplastic Lymphoma Kinase; D018938:Caco-2 Cells; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D003126:Colostrum / Q000737:chemistry*; D016207:Cytokines / Q000737:chemistry* / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D042361:Mammary Glands, Human / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D008895:Milk, Human / Q000737:chemistry*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases; D014018:Tissue Distribution
D002352:Carrier Proteins; D016207:Cytokines; C066845:pleiotrophin; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases