title: β-Hydroxybutyrate Facilitates Fatty Acids Synthesis Mediated by Sterol Regulatory Element-Binding Protein1 in Bovine Mammary Epithelial Cells.
abstract: OBJECTIVE
  In dairy cows, β-hydroxybutyrate (BHBA) is utilized as precursors of de novo synthesized fatty acids in mammary gland. Ketotic cows are characterized by excessive negative energy balance (NEB), which can further increase the blood BHBA concentration. Sterol regulatory element-binding protein1 (SREBP1) and cell death-inducing DNA fragmentation factor-alpha-like effector α (Cidea) play crucial roles in lipid synthesis. Therefore, we hypothesized that BHBA could stimulate SREBP1/Cidea pathway to increase milk fat synthesis in bovine mammary epithelial cells.
  
  
  METHODS
  Bovine mammary epithelial cells were treated with different concentrations of BHBA and transfected with adenovirus to silence SREBP1 expression. The effects of BHBA on the lipid synthesis in bovine mammary epithelial cells were investigated.
  
  
  RESULTS
  The results showed that BHBA could significantly increase the expression of SREBP1, fatty acid synthase (FAS), acetyl-CoA carboxylase α (ACC-α), Cidea and diacylglycerol transferase-1 (DGAT-1), as well as the triglycerides (TG) content in bovine mammary epithelial cells. BHBA treatment also increased the transfer of mature SREBP1 to nucleus compared with control group. However, SREBP1 silencing could significantly down-regulate the overexpression of FAS, ACC-α, Cidea and DGAT-1, as well as TG content induced by BHBA.
  
  
  CONCLUSIONS
  The present data indicate that BHBA can significantly increase TG secretion mediated by SREBP1 in bovine mammary epithelial cells.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Shiqi
authors.initials: S
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Hui
authors.forename: Lin
authors.initials: L
authors.lastname: Lei
authors.forename: Xiliang
authors.initials: X
authors.lastname: Du
authors.forename: Wenwen
authors.initials: W
authors.lastname: Gao
authors.forename: Renhe
authors.initials: R
authors.lastname: Zhang
authors.forename: Guowen
authors.initials: G
authors.lastname: Liu
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Li
authors.forename: Xinwei
authors.initials: X
authors.lastname: Li
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis*; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000502:physiology*
chemical_list: D005227:Fatty Acids; D051780:Sterol Regulatory Element Binding Protein 1; D020155:3-Hydroxybutyric Acid