Premium
Mammary gland differentiation inversely correlates with GDF‐8 expression
Author(s) -
Manickam Ravikumar,
Pena Ramo.,
Whitelaw C. Bruce A.
Publication year - 2008
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.20918
Subject(s) - biology , mammary gland , epithelium , lactation , cellular differentiation , endocrinology , cell type , microbiology and biotechnology , cell growth , cell , messenger rna , medicine , pregnancy , gene , genetics , cancer , breast cancer
GDF‐8 is recognised as an inhibitor of muscle cell growth and differentiation. Although initially thought to be restricted to muscle cells it is now accepted that GDF‐8 expression has a broader tissue distribution. We demonstrate GDF‐8 expression in the mouse mammary gland, which is predominantly associated with epithelial cells and displays an inverse correlation to the differentiated state of the gland. Specifically, the highest GDF‐8 mRNA levels correlate with periods of maximal ductal growth, diminish as pregnancy progressed and are down‐regulated to minimal levels by the onset of lactation as the epithelium differentiates. A similar profile is observed for both GDF‐8 protein processing and reflects Smad2/3 phosphorylation profile. However, in contrast to muscle cells, GDF‐8 neither reduces proliferation nor induces p21 expression levels in mammary epithelial cells. These data implicate a role for GDF‐8 in mammary epithelial cell differentiation and demonstrate that GDF‐8 has cell‐type specific activities. Mol. Reprod. Dev. 75: 1783–1788, 2008. © 2008 Wiley‐Liss, Inc.