Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados-IPN, México City, Mexico.
Department of Cell Biology, Centro de Investigación y de Estudios Avanzados-IPN, México City, Mexico.
PLoS One. 2019 Jul 30;14(7):e0220393. doi: 10.1371/journal.pone.0220393. eCollection 2019.
The wild type huntingtin protein (Htt), supports the production of brain-derived neurotrophic factor (BDNF), a survival factor for striatal neurons, through cytoplasmic sequestering of RE-1silencing transcription factor (REST). In Huntington´s Disease an inherited degenerative disease, caused by a CAG expansion in the 5´coding region of the gene, the mutant huntingtin protein (mHtt), causes that REST enters pathologically into the nucleus of cells, resulting in the repression of neuronal genes including BDNF, resulting in the progressive neuronal death. It has been reported that Htt associates with Hsp90 and this interaction is involved in regulation of huntingtin aggregation. Discovering mechanisms to reduce the cellular levels of mutant huntingtin and REST provide promising strategies for treating Huntington disease. Here, we use the yeast two-hybrid system to show that N-terminus or REST interacts with the heat shock protein 90 (Hsp90) and identifies REST as an Hsp90 Client Protein. To assess the effects of Hsp90 we used antisense oligonucleotide, and evaluated the levels mHtt and REST levels. Our results show that direct knockdown of endogenous Hsp90 significantly reduces the levels of REST and mutant Huntingtin, decreased the percentage of cells with mHtt in nucleus and rescued cells from mHtt-induced cellular cytotoxicity. Additionally Hsp90-specific inhibitors geldanamicyn and PUH71 dramatically reduced mHtt and REST levels, thereby providing neuroprotective activity. Our data show that Hsp90 is necessary to maintain the levels of REST and mHtt, which suggests that the interactions between Hsp90-REST and Hsp90-Huntingtin could be potential therapeutic targets in Huntington's disease.
野生型亨廷顿蛋白（Htt）通过细胞质隔离 RE-1 沉默转录因子（REST）来支持脑源性神经营养因子（BDNF）的产生，BDNF 是纹状体神经元的存活因子。在亨廷顿病（一种由基因 5'编码区 CAG 扩展引起的遗传性退行性疾病）中，突变型亨廷顿蛋白（mHtt）导致 REST 病理性进入细胞核，从而抑制神经元基因包括 BDNF 的表达，导致进行性神经元死亡。已经报道 Htt 与 Hsp90 相关联，并且这种相互作用涉及亨廷顿蛋白聚集的调节。发现减少突变型亨廷顿蛋白和 REST 的细胞内水平的机制为治疗亨廷顿病提供了有希望的策略。在这里，我们使用酵母双杂交系统表明 N 端或 REST 与热休克蛋白 90（Hsp90）相互作用，并将 REST 鉴定为 Hsp90 客户蛋白。为了评估 Hsp90 的作用，我们使用了反义寡核苷酸，并评估了 mHtt 和 REST 水平。我们的结果表明，内源性 Hsp90 的直接敲低显著降低了 REST 和突变 Huntingtin 的水平，降低了细胞核中具有 mHtt 的细胞的百分比，并挽救了 mHtt 诱导的细胞毒性的细胞。此外，Hsp90 特异性抑制剂 geldanamicyn 和 PUH71 显著降低了 mHtt 和 REST 水平，从而提供了神经保护活性。我们的数据表明 Hsp90 是维持 REST 和 mHtt 水平所必需的，这表明 Hsp90-REST 和 Hsp90-Huntingtin 之间的相互作用可能是亨廷顿病的潜在治疗靶点。
