Expression of PTHrP and the PTH/PTHrP receptor in purified alveolar epithelial cells, myoepithelial cells, and stromal fibroblasts derived from the lactating rat mammary gland.
Parathyroid hormone-related protein (PTHrP) is produced by the lactating mammary gland and secreted into the milk; however, the function of PTHrP during lactation is unknown. Since messenger RNA for both PTHrP and the PTH/PTHrP receptor have been demonstrated within mammary tissue, a paracrine or autocrine function for PTHrP has been proposed. To investigate this hypothesis in lactating tissue, the expression of PTHrP and the PTH/PTHrP receptor was examined in purified subpopulations of cells derived from lactating rat mammary glands. Subpopulations of stromal, myoepithelial, and alveolar epithelial cells were isolated from mammary tissue using enzymatic digestion and immunomagnetic purification. Isolated cells were phenotypically characterized by immunohistochemistry and ultrastructural morphology. The purity of the separated alveolar and myoepithelial cells was assessed ultrastructurally and ranged from 91 to 96%. Messenger RNA and protein expression of PTHrP and the PTH/PTHrP receptor were examined using reverse transcription polymerase chain reaction, immunohistochemistry, and Western blot analysis, respectively. PTHrP mRNA and protein were expressed in alveolar epithelial cells and stromal fibroblasts, whereas PTH/PTHrP receptor mRNA and protein were expressed in all three cell types. The expression patterns for PTHrP and the PTH/PTHrP receptor support an autocrine or paracrine function for PTHrP in alveolar epithelial cells and stromal fibroblasts and a paracrine function for PTHrP in myoepithelial cells in the rat mammary gland during lactation.
Wojcik
S F
SF
College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, 43210, USA.
Capen
C C
CC
Rosol
T J
TJ
D000818:Animals; D019898:Autocrine Communication; D004847:Epithelial Cells / Q000737:chemistry* / Q000166:cytology; D005260:Female; D005347:Fibroblasts / Q000737:chemistry* / Q000166:cytology; D007150:Immunohistochemistry; D018189:Immunomagnetic Separation; D007774:Lactation; D008321:Mammary Glands, Animal / Q000737:chemistry* / Q000166:cytology*; D019899:Paracrine Communication; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D044168:Receptor, Parathyroid Hormone, Type 1; D018016:Receptors, Parathyroid Hormone / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000737:chemistry / Q000166:cytology; D014018:Tissue Distribution
D044162:Parathyroid Hormone-Related Protein; D011506:Proteins; D012333:RNA, Messenger; D044168:Receptor, Parathyroid Hormone, Type 1; D018016:Receptors, Parathyroid Hormone