| Objective:To investigate the antagonistic effect of tranilast on Parkinson’s disease,and to explore whether it directly or indirectly regulates the expression of CD244 by activating aromatic hydrocarbon receptors(AHRs),thereby regulating the peripheral immune response and improving central nervous system inflammation.Method:1.PD mouse model was established by intraperitoneal injection of MPTP(30 mg/kg/d)for 7 days,and the mice were randomly divided into healthy Control group(CONTROL),MPTP+dissolved medium gavage group(PD-VEH),and MPTP+tranilast gavage group(PD-Tra).Open field application test mice athleticism,Western blot detection total TH protein expression level in Brain.Western blot test mice spleen CYP1A1,IDO protein expression.Flow cytometry was used to detect the expression of CD4+T,CD8+T lymphocytes in the spleen and brain of mice,also detect the expression of regulatory T cells(Treg)cell and CD244+dendritic cells(CD11b+CD11c+CD244+DCs)in spleen,ELISA detection of proinflammatory cytokines in serum tumor necrosis factor alpha(TNF alpha),interferon gamma(IFN-gamma),interleukin12(IL-12)level,the anti-inflammatory cytokine interleukin 10(IL-10)level.2.Some part of PD mice in the tranilast treatment group were pretreated with the AHR receptor inhibitor CH223191(10 mg/kg/d)for 7days,and this group of mice were named as MPTP+tranilast+CH223191(PD-Tra-CH223191).Open field application test mice athleticism,Western blot test in mice brain TH protein expression level,Western blot test mice spleen CYP1A1,IDO protein expression,Flow cytometry was used to detect the expression of CD4+T,CD8+T lymphocytes in the spleen and brain of mice,detect regulatory T cells(Treg)cell and CD244+dendritic cells expression in spleen,ELISA detection of proinflammatory cytokines in serum TNF alpha,IFN-gamma,IL-12 levels,anti-inflammatory cytokine IL-10 levels.3.The rest part of PD mice in the tranilast treated group were injected with CD244 monoclonal antibody via tail vein(50 mg/mice/d),and CD244 was compared with monoclonal Ig G antibody(ISO)in the negative monoclonal mice,which were divided into MPTP+tranilast gavage+CD244 antibody injection group(PD-tra-anti CD244)and MPTP+tranilast gavage+monoclonal Ig G antibody injection group(PD-tra-ISO).The open field assay was used to detect the exercise ability of mice.The expression of total TH protein in the brain of mice was detected by Western blot,the expression of CD4+T,CD8+T lymphocytes in the spleen and brain of mice,and the expression of regulatory T cells(Treg)cell,CD244+dendritic cells in spleen was also detected by flow cytometry,the levels of pro-inflammatory cytokines TNF-α,IFN-γ,IL-12 levels in serum and anti-inflammatory cytokine IL-10 were detected by ELISA.Results:1.Tranilastat has anti-Parkinson’s disease effect: it can improve the exercise ability of PD mice,up-regulate the expression of Th protein in the brain,increase the proportion of peripheral CD4+T,CD8+T,Treg and CD244+dendritic cells,improve the infiltration of central CD4+T and CD8+T cells,down-regulate the levels of inflammatory cytokines TNF-α,IFN-γ and IL-12 in serum,and up-regulate the level of anti-inflammatory cytokine IL-10.2.The anti-Parkinson’s effect of tranilast is rely on the aromatic hydrocarbon receptor pathway: Tranilast can increase mice spleen CYP1A1,IDO protein expression,but after pretreatment of CH223191,the effect of tranilast reverse.the motor ability of PD mice was weakened,CH223191 also down-regulated the expression of TH protein in the brain,down-regulated the number of peripheral CD4+T,CD8+T,Treg,CD244+dendritic cells,aggravated the central CD4+,CD8+ cell infiltration,up-regulated the levels of inflammatory cytokines TNF-α,IFN-γ,IL-12 in serum,down-regulated the level of anti-inflammatory cytokine IL-10.3.The immune checkpoint CD244 plays a role in the regulation of peripheral immune response and is related to tryptophan metabolism.The application of CD244 monoclonal antibody can partially cancel the protective effect of tranilast,which leads to the weakened motor ability of PD mice and may down-regulate the expression of TH protein in the brain.The number of peripheral CD4+T,CD8+T,Treg and CD244+dendritic cells were down-regulated,CD4+T and CD8+T cell infiltration in central nervous system was aggravated,and the levels of inflammatory cytokines TNF-α and IFN-γ in serum were up-regulated.Conclusion:Tranilast has anti-PD effect,and its mechanism may be as follows: it can protect dopaminergic neurons by promoting AHR-ligand production,inhibiting peripheral inflammatory response and lymphocyte infiltration in the central system.Conclusion:Tranilast has anti-PD effect,and its mechanism may be as follows: by promoting AHR-ligand production,regulating peripheral immune imbalance,inhibiting peripheral inflammatory response,and improving lymphocyte infiltration in the neural system. |
