title: [Microglial activation and inflammatory cytokine expression in the brain of chronic Toxoplasma gondii-infected mice].
abstract: OBJECTIVE
  To investigate microglial activation and inflammatory cytokine expression in chronic Toxoplasma gondii infection.
  
  
  METHODS
  Thirty mice were randomly divided into chronic T. gondii infection group and normal control group. Each mouse in infection group was infected orally with 30 cysts of the TgCtwh6 strain. Normal group received 0.3 ml normal saline. On the 60th day after infection, immunohistochemical staining was performed to assess the number of microglia and morphological change. The expression of inflammatory cytokines (IL-1beta, IL-6, and TNF-alpha) was measured by RT-PCR. The expression of iNOS was determined by Western blotting and immunofluorescence.
  
  
  RESULTS
  Immunohistochemistry analysis showed that the number of Iba-1 positive cells in the cortex and hippocampus of infection group (16.5 +/- 0.8 and 17.9 +/- 1.1) was higher than that of the control (8.4 +/- 0.2 and 10.3 +/- 0.8)(P < 0.05). Iba-1 positive cells (i.e. microglia) had larger cell bodies and ramified morphology. RT-PCR result indicated that mRNA level of IL-1beta, IL-6, and TNF-alpha in infection group (0.862 +/- 0.169, 0.407 +/- 0.158, and 0.305 +/- 0.073) was significantly higher than that of the control (0.149 +/- 0.030, 0.037 +/- 0.008, and 0.001 +/- 0.001) (P < 0.05). The iNOS protein expression in infection group (0.252 +/- 0.164) was higher than that of the control (0.0433 +/- 0.004) (P < 0.05). Immunofluorescence demonstrated that iNOS protein released by activated microglia.
  
  
  CONCLUSIONS
  Chronic T. gondii infection caused microglial activation, which up-regulate the level of IL-1beta, IL-6, TNF-alpha, and iNOS.
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Xue-Long
authors.initials: XL
authors.lastname: Wang
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Shen
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Lan-Ting
authors.initials: LT
authors.lastname: Kong
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Wang
authors.forename: He
authors.initials: H
authors.lastname: Chen
mesh_terms: D000818:Animals; D001921:Brain / Q000469:parasitology*; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D017628:Microglia / Q000166:cytology / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D014122:Toxoplasma; D014123:Toxoplasmosis / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse