Complex Effects of the ZSCAN21 Transcription Factor on Transcriptional Regulation of -Synuclein in Primary Neuronal Cultures and in Vivo
Complex Effects of the ZSCAN21 Transcription Factor on Transcriptional Regulation of -Synuclein in Primary Neuronal Cultures and in Vivo
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DOI：
10.1074/jbc.m115.704973
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发表时间：
2016-04-15
影响因子：
4.8
通讯作者：
Stefanis, Leonidas
中科院分区：
文献类型：
--
作者：
Dermentzaki, Georgia;Paschalidis, Nikolaos;Stefanis, Leonidas
突触核蛋白是一种由SNCA基因编码的突触前神经元蛋白，与帕金森病（PD）密切相关。PD发病机制与SNCA水平升高有关；然而，控制SNCA表达的转录元件仍然难以捉摸。先前在PC12细胞中的实验表明，转录因子锌指和SCAN domain containing 21 （ZSCAN21）在SNCA转录中起重要的调控作用。目前，我们鉴定了ZSCAN21在原代神经元培养和体内SNCA转录中的作用。我们发现ZSCAN21在发育中表达于大鼠大脑不同区域的神经元中。我们在大鼠皮质培养物中证实了它与SNCA内含子1区域的结合。慢病毒介导的ZSCAN21沉默显著增加了这些培养物中SNCA启动子活性、mRNA和蛋白质水平。相比之下，ZSCAN21沉默减少了神经球培养中的SNCA。有趣的是，ZSCAN21在皮质神经元中的过表达导致mRNA表达强劲，但蛋白表达可忽略，这表明ZSCAN21蛋白水平在初级神经元中受到转录后和/或翻译后的严格调控。在出生后和成年海马（与非运动性PD症状相关的区域）中，腺相关病毒介导的ZSCAN21的有效敲低显示SNCA水平没有显著改变。总的来说，我们的研究表明，ZSCAN21参与了原代神经元培养中SNCA的转录调控，但影响的方向是可变的，可能取决于神经元的成熟程度。然而，在大鼠大脑中，可能由于代偿机制，ZSCAN21下调后观察到的SNCA水平没有改变，这意味着ZSCAN21在体内不是SNCA的主要调节剂。
-Synuclein, a presynaptic neuronal protein encoded by the SNCA gene, is strongly implicated in Parkinson disease (PD). PD pathogenesis is linked to increased SNCA levels; however, the transcriptional elements that control SNCA expression are still elusive. Previous experiments in PC12 cells demonstrated that the transcription factor zinc finger and SCAN domain containing 21 (ZSCAN21) plays an important regulatory role in SNCA transcription. Currently, we characterized the role of ZSCAN21 in SNCA transcription in primary neuronal cultures and in vivo. We found that ZSCAN21 is developmentally expressed in neurons in different rat brain regions. We confirmed its binding in the intron 1 region of SNCA in rat cortical cultures. Lentivirus-mediated silencing of ZSCAN21 increased significantly SNCA promoter activity, mRNA, and protein levels in such cultures. In contrast, ZSCAN21 silencing reduced SNCA in neurosphere cultures. Interestingly, ZSCAN21 overexpression in cortical neurons led to robust mRNA but negligible protein expression, suggesting that ZSCAN21 protein levels are tightly regulated post-transcriptionally and/or post-translationally in primary neurons. Efficient adeno-associated virus-mediated knockdown of ZSCAN21 in the postnatal and adult hippocampus, an area linked with non-motor PD symptoms, revealed no significant alterations in SNCA levels. Overall, our study demonstrates that ZSCAN21 is involved in the transcriptional regulation of SNCA in primary neuronal cultures, but the direction of the effect is variable, likely depending on neuronal maturation. However, the unaltered SNCA levels observed following ZSCAN21 down-regulation in the rat brain, possibly due to compensatory mechanisms, imply that ZSCAN21 is not a master regulator of SNCA in vivo.