Transcriptome analysis of mammary tissues reveals complex patterns of transporter gene expression during pregnancy and lactation.
As a complex Ca2+-rich fluid mixture of water, casein, lactose and several ions, milk secretion requires a number of unknown transporters, which can be identified by a genome-wide microarray study in mammary tissues of lactating animals. Ca2+ was reported to be secreted across mammary epithelial cells through the transcellular pathway, presumably involving TRPC (canonical transient receptor potential) channels. In the present study, we have used quantitative real-time PCR to demonstrate that the human mammary cell line MCF-7, as well as rat mammary tissues from pregnant and lactating rats, expressed TRPC1, TRPC5 and TRPC6. Expression of TRPC1, TRPC5 and TRPC7 were markedly up-regulated, whereas that of TRPC3 and TRPC4 was down-regulated in the early lactating period. To further identify other transporter genes affected by lactation, a highly sensitive Illumina microarray featuring Bead Array technology was performed on RNA samples from mammary tissues of lactating rats. We found that, of the 384 transcripts changed during lactation, 31 transcripts were involved in the transport of water and electrolytes, such as Ca2+, Na+, K+, Cl-, I-, Fe2+, sulfate and phosphate. The present study, therefore, provides information for further investigation of the mechanism of lactation-induced transport adaptation in mammary epithelial cells.
Anantamongkol
Utchariya
U
Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
Charoenphandhu
Narattaphol
N
Wongdee
Kannikar
K
Teerapornpuntakit
Jarinthorn
J
Suthiphongchai
Tuangporn
T
Prapong
Siriwan
S
Krishnamra
Nateetip
N
D000818:Animals; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000166:cytology / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D051381:Rats; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
D026901:Membrane Transport Proteins; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; C489571:TRPC4 ion channel; C491780:TRPC5 protein, human; C498501:TRPC7 protein, human; C503500:Trpc5 protein, rat; C498498:Trpc7 protein, rat; C096351:transient receptor potential cation channel, subfamily C, member 1