PD模型小鼠中脑特异性表达突变型A53T α-Synuclein基因对外周单核细胞浸润的影响

The effect of specific expression of mutant A53T α-Synuclein gene in the midbrain on monocyte infiltration in the midbrain in Parkinson's disease mice

目的小鼠中脑特异性表达突变型A53T α-Synuclein(α-Syn)后,研究其对中脑发生外周单核细胞浸润的影响。方法本研究使用转突变型A53Tα-Syn基因的帕金森病小鼠模型(以下简称Pitx3/A53T小鼠),应用免疫荧光共定位技术检测2、12月龄的Pitx3/A53T及non-Transgenic(nTg)小鼠中脑黑质致密部(SNC)、腹侧背盖区(VTA)及黑质网状部(SNR)的P2Y12、CD11b、CD169和Iba-1的表达情况。结果免疫荧光结果显示,在2月龄的Pitx3/A53T和nTg小鼠,以及12月龄的nTg小鼠中脑部位(SNC、VTA、SNR),仅检测到中枢神经系统(CNS)小胶质细胞(P2Y12+CD11b+和CD169-Iba-1+)。在12月龄的Pitx3/A53T小鼠中脑部位,除了有CNS小胶质细胞外,其SNR部位还特异性存在外周单核细胞(P2Y12-CD11b+和CD169+Iba-1+)。此外,在2月龄时,Pitx3/A53T小鼠中脑部位的P2Y12表达水平较nTg小鼠高(P<0.05,SNC、VTA、SNR);12月龄时,Pitx3/A53T小鼠中脑部位的P2Y12表达水平明显低于nTg小鼠(P<0.01,SNC、VTA;P<0.001,SNR);与2月龄的小鼠相比,12月龄小鼠中脑部位的P2Y12表达水平明显降低(P<0.001,Pitx3/A53T;P<0.05,nTg)。结论小鼠中脑特异性表达突变型A53Tα-Syn后,其在老龄时中脑发生外周单核细胞浸润。而且小鼠中脑部位P2Y12的表达水平变化与年龄和突变型A53Tα-Syn关系密切。

Objective To observe whether the specific expression of A53 T mutant α-Synuclein(A53T α-Syn) gene in the midbrain can contribute to monocyte infiltration in the midbrain of these mice. Methods Here, we addressed this issue in transgenic mice for the A53 T mutant α-Syn, a mouse model of Parkinson's disease and hereinafter referred to as Pitx3/A53 T mice. Expression of P2Y12, CD11 b, CD169 and Iba-1 in the midbrain including SNC, VTA and SNR of Pitx3/A53 T and non-Transgenic(nTg)mice at the age of 2 and 12 months were detected by immunofluorescence colocalization technique. Results Immunofluorescence showed that CNS microglia(P2Y12+CD11b+or CD169-Iba-1+) were detected in the midbrain(SNC, VTA, SNR) of 2-month-old Pitx3/A53 T and nTg mice, similarly in 12-month-old nTg mice. But in the midbrain of 12-month-old Pitx3/A53 T mice, monocyte(P2Y12-CD11b+or CD169+Iba-1+) were particularly detected in the SNR except CNS microglia in the midbrain. Additionally, compared to 2-month-old nTg mice, a significant increase of P2Y12 expression levels was observed in the midbrain(P<0.05, SNC, VTA,SNR). Whereas, at 12 months of age, P2Y12 expression levels in the midbrain of Pitx3/A53 T mice was obviously decreased compared with nTg mice(P<0.01, SNC, VTA; P<0.001, SNR). Moreover, P2Y12 expression levels declined between 2 months and 12 months of age in Pitx3/A53 T and nTg mice(P<0.001, Pitx3/A53T; P<0.05, nTg). Conclusion These findings highlight that specific expression of A53 T mutant α-Syn in the midbrain can contribute to the monocyte infiltration in the midbrain of elderly mice. Moreover,changes of P2Y12 expression in the midbrain are associated with age and A53 T mutant α-syn.