Department of Pediatrics, Neurobiology Program, Children's Memorial Research Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60614, USA.
Dev Neurobiol. 2012 Jun;72(6):906-17. doi: 10.1002/dneu.20989.
Experimental models of Parkinson's disease (PD) created by aberrant expression of the alpha-synuclein (SNCA) coding region have been reported. However, noncoding regions function in normal physiology and recent in vitro studies have shown that microRNAs-7 and -153 regulate SNCA expression by binding the 3'UTR. Here, effects of different hSNCA forms were examined in vivo. Adult, male rats were injected into one substantia nigra (SN) with AAV-wtSNCA, AAV-S129A hSNCA, or AAV-S129D hSNCA either with or without a portion of the native 3'UTR. DA neurons in SN that maintained striatal (ST) projections at the end of treatment were retrogradely labeled by bilateral ST fluorogold (FG) injections and FG-positive DA neurons in SN were counted. At 5 weeks, hSNCA coding vectors reduced numbers of FG-positive neurons in injected SN compared with uninjected SN (wtSNCA, p = 0.05; S129A/D hSNCA, p = 0.01). At 7 and 9 weeks, wtSNCA- and S129D hSNCA-treated rats exhibited recovery, but S129A hSNCA-injected rats did not (p = 0.01). In contrast, numbers of FG-positive neurons were unaffected by hSNCA expression when the 3'UTR was included. When FG-positive neurons were expressed as the ratio of numbers in injected to uninjected sides, the S129A hSNCA coding vector resulted in the highest decrease at 9 weeks versus wtSNCA (p = 0.05) or S129D hSNCA (p = 0.01). Inclusion of the 3'UTR resulted in no significant differences in FG-positive neuron ratios. These data suggest that inclusion of the 3'UTR protects against S129A hSNCA-induced loss of nigrostriatal-projecting DA neurons in vivo and that mis-regulation of hSNCA expression and function at noncoding regions contribute to PD pathogenesis.
已报道过通过异常表达α-突触核蛋白（SNCA）编码区创建的帕金森病（PD）实验模型。然而，非编码区在正常生理中起作用，最近的体外研究表明 microRNAs-7 和 -153 通过结合 3'UTR 来调节 SNCA 的表达。在这里，检查了不同 hSNCA 形式在体内的影响。成年雄性大鼠将 AAV-wtSNCA、AAV-S129A hSNCA 或 AAV-S129D hSNCA 注入一侧黑质（SN）中，无论是否存在天然 3'UTR 的一部分。治疗结束时，通过双侧纹状体（ST）氟金葡菌（FG）注射将保留 ST 投射的 SN 中的 DA 神经元逆行标记，并对 SN 中的 FG-阳性 DA 神经元进行计数。在 5 周时，与未注射 SN 相比，hSNCA 编码载体减少了注射 SN 中的 FG-阳性神经元数量（wtSNCA，p = 0.05；S129A/D hSNCA，p = 0.01）。在 7 和 9 周时，wtSNCA 和 S129D hSNCA 治疗的大鼠表现出恢复，但 S129A hSNCA 注射的大鼠没有（p = 0.01）。相比之下，当包含 3'UTR 时，hSNCA 的表达不受影响。当 FG-阳性神经元的数量表示为注射侧与未注射侧的比值时，与 wtSNCA（p = 0.05）或 S129D hSNCA（p = 0.01）相比，S129A hSNCA 编码载体在 9 周时导致最高的降低。包含 3'UTR 不会导致 FG-阳性神经元比值的显著差异。这些数据表明，包含 3'UTR 可防止体内 S129A hSNCA 诱导的黑质纹状体投射 DA 神经元丢失，并且非编码区的 hSNCA 表达和功能的错误调节导致 PD 发病机制。
