Antioxidant and antibacterial genes are upregulated in early involution of the mouse mammary gland: sharp increase of ceruloplasmin and lactoferrin in accumulating breast milk.
The mammary gland develops mainly after birth, and shows a repeated cycle of pregnancy-triggered proliferation, differentiation for lactation, and a regressive phase after weaning known as involution. Compared to the proliferation and differentiation phases, the molecular mechanisms of involution are largely unknown. In the present study we screened genes that could play a potential role in early involution of the mouse mammary gland using fluorescent differential display followed by gene-specific reverse transcription-polymerase chain reaction. We found that five genes were upregulated more than twofold 48 h after weaning: ceruloplasmin, chemokine (CXC motif) ligand 4, epoxide hydrolase 1, lactoferrin, and properdin P factor. The products of these genes can be linked to defense against oxidative stress and/or infectious bacteria. Electrophoretic analysis and mass spectrometry of milk proteins showed that the concentrations of ceruloplasmin and lactoferrin in milk were increased fivefold and more than 38-fold, respectively, within 48 h after weaning. These increases were in contrast to the constant presence of other major proteins including albumin, caseins, transferrin, and whey acidic protein. Ceruloplasmin and lactoferrin may cooperate in the defense of the mammary gland in the postlactation period.
Nakamura
Mayuko
M
Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
Tomita
Akiko
A
Nakatani
Hajime
H
Matsuda
Tsukasa
T
Nadano
Daita
D
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism; D001483:Base Sequence; D002570:Ceruloplasmin / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D007774:Lactation / Q000235:genetics; D007781:Lactoferrin / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008892:Milk / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000302:isolation & purification; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D018076:DNA, Complementary; D010446:Peptide Fragments; D002570:Ceruloplasmin; D007781:Lactoferrin