title: Over-expression of Toll-like receptor 2 up-regulates heme oxygenase-1 expression and decreases oxidative injury in dairy goats.
abstract: BACKGROUND
  Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2 (TLR2) is important for host recognition of invading Gram-positive microbes. Over-expression ofTLR2in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.
  
  
  METHODS
  We over-expressedTLR2in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria, triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from theTLR2-positive transgenic goats, and induced over-expression of activator protein-1 (AP-1),phosphatidylinositol 3-kinase (PI3K) and transcription factor nuclear factor kappa B (NF-κB) and inflammation factors downstream of the signal pathway.
  
  
  RESULTS
  Compared with wild-type controls, measurements of various oxidative stress-related molecules showed thatTLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased mRNA levels of transcription factor NF-E2-related factor-2 (Nrf2) and the downstream gene, heme oxygenase-1 (HO-1). When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.
  
  
  CONCLUSIONS
  The results indicate that the oxidative injury in goats over-expressingTLR2was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation geneHO-1by activation of the Nrf2 signal pathway.
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China.
authors.forename: Shoulong
authors.initials: S
authors.lastname: Deng
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.|National key Lab of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yu
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Wuqi
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Shuotian
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater, OK 74078 USA.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Deng
authors.affiliation: College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030 People's Republic of China.
authors.forename: Yuchang
authors.initials: Y
authors.lastname: Yao
authors.affiliation: State Oceanic Administration, Beijing, 100860 People's Republic of China.
authors.forename: Baolu
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Guoshi
authors.initials: G
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China.
authors.forename: Yixun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.|National key Lab of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193 People's Republic of China.
authors.forename: Zhengxing
authors.identifier: 0000-0002-2060-0324
authors.initials: Z
authors.lastname: Lian
keywords: Haem oxygenase; Nrf2 signal pathway; Toll-like receptor 2; Transgenic goats