Proteomic analysis of the mouse mammary gland is a powerful tool to identify novel proteins that are differentially expressed during mammary development.
After lactation, the mouse mammary gland undergoes apoptosis and tissue remodelling as the gland reverts to its prepregnant state. This complex change was investigated using 2-DE. An integrated database was produced from lactation and involution proteomes. Forty-four molecular cluster indexes (MCIs) that showed altered expression from lactation to involution were selected for MS analysis. Of these, 32 gave protein annotations, 18 of which were unequivocal proteins. Selected proteins were then studied across all of development, including pregnancy, using data integrated from another proteome database. Two proteins, the RNA polymerase B transcription factor 3 (BTF3) and the minichromosome maintenance protein 3 (MCM3), although initially selected on the basis of the lactation/involution criteria, had expression profiles that indicated an additional role in mammary development and were further analysed. BTF3, a transcription factor previously not described in the mammary gland, was up-regulated strongly in pregnancy, indicating an involvement in alveolar growth. MCM3's expression was greatest in pregnancy and late involution, decreasing through lactation. Immunohistochemistry localised MCM3 to the mammary epithelium, where a greater proportion of cells stained than for the proliferation marker Ki67. MCM3 expression during lactation may identify cells that are licensed to repopulate the gland during cell loss in lactation and following involution.
Davies
Claire R
CR
Department of Pathology, Division of Cancer Sciences and Molecular Pathology, Glasgow, Scotland, UK.
Morris
Joanna S
JS
Griffiths
Matthew R
MR
Page
Martin J
MJ
Pitt
Andrew
A
Stein
Torsten
T
Gusterson
Barry A
BA
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D018797:Cell Cycle Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D030562:Databases, Protein; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D007774:Lactation / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism*; D013058:Mass Spectrometry; D051379:Mice; D008807:Mice, Inbred BALB C; D064126:Minichromosome Maintenance Complex Component 3; D009687:Nuclear Proteins / Q000378:metabolism; D010449:Peptide Mapping; D011247:Pregnancy; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods*; D014157:Transcription Factors / Q000378:metabolism
D015415:Biomarkers; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; C513269:Mcm3 protein, mouse; C498355:Mki67 protein, mouse; D009687:Nuclear Proteins; D020543:Proteome; D014157:Transcription Factors; C063552:transcription factor BTF3; D064126:Minichromosome Maintenance Complex Component 3