Proteome analysis of functionally differentiated bovine (Bos indicus) mammary epithelial cells isolated from milk

Jagadeesh Janjanam, ICAR - National Dairy Research Institute
Manu Jamwal, ICAR - National Dairy Research Institute
Surender Singh, ICAR - National Dairy Research Institute
Saravanan Kumar, International Centre for Genetic Engineering and Biotechnology, New Delhi
Aswini K. Panigrahi, King Abdullah University of Science and Technology
Gururao Hariprasad, All India Institute of Medical Sciences, New Delhi
Manoj K. Jena, ICAR - National Dairy Research Institute
Vijay Anand, ICAR - National Dairy Research Institute
Sudarshan Kumar, ICAR - National Dairy Research Institute
Jai K. Kaushik, ICAR - National Dairy Research Institute
Ajay K. Dang, ICAR - National Dairy Research Institute
Manishi Mukesh, ICAR - National Bureau of Animal Genetic Resources, Karnal
Bishnu P. Mishra, ICAR - National Bureau of Animal Genetic Resources, Karnal
Alagiri Srinivasan, All India Institute of Medical Sciences, New Delhi
Vanga S. Reddy, International Centre for Genetic Engineering and Biotechnology, New Delhi
Ashok K. Mohanty, ICAR - National Dairy Research Institute

Abstract

Mammary gland is made up of a branching network of ducts that end in alveoli. Terminally differentiated mammary epithelial cells (MECs) constitute the innermost layer of aveoli. They are milk-secreting cuboidal cells that secrete milk proteins during lactation. Little is known about the expression profile of proteins in the metabolically active MECs during lactation or their functional role in the lactation process. In the present investigation, we have reported the proteome map of MECs in lactating cows using 2DE MALDI-TOF/TOF MS and 1D-Gel-LC-MS/MS. MECs were isolated from milk using immunomagnetic beads and confirmed by RT-PCR and Western blotting. The 1D-Gel-LC-MS/MS and 2DE-MS/MS based approaches led to identification of 431 and 134 proteins, respectively, with a total of 497 unique proteins. Proteins identified in this study were clustered into functional groups using bioinformatics tools. Pathway analysis of the identified proteins revealed 28 pathways (p < 0.05) providing evidence for involvement of various proteins in lactation function. This study further provides experimental evidence for the presence of many proteins that have been predicted in annotated bovine genome. The data generated further provide a set of bovine MEC-specific proteins that will help the researchers to understand the molecular events taking place during lactation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.