Tyrobp promotes neuroinflammation in Tourette's syndrome model mice and related mechanisms / 中华行为医学与脑科学杂志

ABSTRACT

Objective:To explore the effects and possible mechanisms of Tyrobp gene on neuroinflammation in Tourette's syndrome mice.Methods:Twenty C57BL/ 6J and Tyrobp knock-out male mice aged 6 weeks were randomly divided into 4 groups according to random number table method: WT+ NS group, Tyrobp -/-+ NS group, WT+ IDPN group and Tyrobp -/-+ IDPN group. Mice in WT+ IDPN group and Tyrobp -/-+ IDPN group were injected with IDPN intraperitoneally at a dose of 150 mg/kg·d, while mice in WT+ NS group and Tyrobp -/-+ NS group were injected with equal volume of normal saline, once a day for 7 days. Then stereotypical behavior of mice were evaluated. Western blot was used to detect the levels of Tyrobp, TNF-α, IL-6, IL-1β, TLR4, Myd88, p-NF-κB p65 and p-IκBα in the striatum of mice. Immunofluorescence staining was used to observe the activation of microglia. Statistical analysis was performed using GraphPad Prism 8.0 software, and t-test was used for comparison between two groups. One-way ANOVA was used to compare the means of multiple samples, and LSD test was used for further pairwise comparison. Results:The results of behavior assessment showed that there were significant differences in the motor stereotypic behavior and categorical stereotypic behavior score( F=270.9, 379.7, P<0.01), and the scores in WT+ IDPN group were higher than those in Tyrobp -/-+ IDPN group (motor stereotypic behavior (3.23±0.26), (2.13±0.21), t=9.02, P<0.05; categorical stereotypic behavior (45.80±4.29), (26.60±3.48), t=12.00, P<0.05). Western blot results showed that there were significant differences in the protein expression level of TNF-α, IL-6, IL-1β, TLR4, Myd88, p-NF-κB p65 and p-IκBα ( F=29.07, 23.09, 39.36, 57.6, 52.55, 15.50, 40.48, all P<0.05), the level of those in WT + IDPN group was higher than those in WT+ NS group( t=8.31, 7.37, 8.13, 11.43, 10.47, 6.05, 9.96, all P<0.05), Tyrobp -/-+ IDPN group was higher than Tyrobp -/-+ NS group ( t=3.60, 3.00, 5.84, 4.81, 3.59, 2.26, 4.68, all P<0.05), and WT + IDPN group was higher than Tyrobp -/-+ IDPN group ( t=3.97, 3.93, 4.14, 6.40, 7.63, 3.45, 3.03, all P<0.05). Immunofluorescence showed that microglial cells in the striatum region of mice in WT+ IDPN group and Tyrobp -/-+ IDPN group were enlarged and microglial cells were activated, and the activation pattern of microglial cells in WT+ IDPN group was more obvious than that in Tyrobp -/-+ IDPN group. Conclusion:Tyrobp may be involved in the pathogenesis of Tourette's syndrome by promoting neuroinflammation mediated by TLR4/Myd88/NF-κB signaling pathway.