title: Effects of glucose on lactose synthesis in mammary epithelial cells from dairy cow.
abstract: BACKGROUND
  Lactose, as the primary osmotic component in milk, is the major determinant of milk volume. Glucose is the primary precursor of lactose. However, the effect of glucose on lactose synthesis in dairy cow mammary glands and the mechanism governing this process are poorly understood.
  
  
  RESULTS
  Here we showed that glucose has the ability to induce lactose synthesis in dairy cow mammary epithelial cells, as well as increase cell viability and proliferation. A concentration of 12 mM glucose was the optimum concentration to induce cell growth and lactose synthesis in cultured dairy cow mammary epithelial cells. In vitro, 12 mM glucose enhanced lactose content, along with the expression of genes involved in glucose transportation and the lactose biosynthesis pathway, including GLUT1, SLC35A2, SLC35B1, HK2, β4GalT-I, and AKT1. In addition, we found that AKT1 knockdown inhibited cell growth and lactose synthesis as well as expression of GLUT1, SLC35A2, SLC35B1, HK2, and β4GalT-I.
  
  
  CONCLUSIONS
  Glucose induces cell growth and lactose synthesis in dairy cow mammary epithelial cells. Protein kinase B alpha acts as a regulator of metabolism in dairy cow mammary gland to mediate the effects of glucose on lactose synthesis.
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Hou
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Qu
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Gao
authors.affiliation: Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University, Harbin, 150030, China. qzli@neau.edu.cn.
authors.forename: Qingzhang
authors.initials: Q
authors.lastname: Li
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005260:Female; D055785:Gene Knockdown Techniques; D005947:Glucose / Q000494:pharmacology*; D007785:Lactose / Q000096:biosynthesis*; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D051057:Proto-Oncogene Proteins c-akt; D005947:Glucose; D007785:Lactose
keywords: AKT1; Dairy cow; Glucose; Lactose synthesis; Mammary epithelial cell