MSS1对LPS介导的神经炎症反应的调节及其在帕金森病中的作用研究

There was abundant evidence showing that the constant activation and release of pro-inflammatory factors promoted the development of Parkinson's Disease. Thus, the inhibition of these pro-inflammatory mediators offers a potential therapeutic strategy for the treatment of Parkinson's Disease..We previously found that rifampicin improved survival of catecholamine and α-synuclein-containing cells, which degenerate in PD, thus might be therapeutic in this disease. Rifampicin suppressed the release of pro-inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) from BV2 microglial cells that were pre-treated with lipopolysaccharides (LPS). It acted as a neuroprotector to increase neuronal survival against microglia-induced neuron death. Our results strongly supported rifampicin as a potential therapeutic for the treatment of neurodegenerative diseases. Despite of the above findings, the mechanism through which rifampicin inhibits inflammation in microglial cells is not completely understood..NF-κB is an important transcription factor for the expression of proinflammatory mediators. In unstimulated cells, nuclear factor-kappa B (NF-kB) binds to IkappaBalpha (IκBα) and its activity is inhibited. The activation of NF-kB is initiated by signal-induced degradation of IκBα proteins, which occurs primarily via the ubiquitin-proteasome pathway . Proteasomes play a critical role in protein degradation and is essential to many intracellular processes. The 26S proteasome, a multi-subunit enzyme complex, is a major cellular non-lysosomal protease. Modulation of the ubiquitin-26S proteasome system (UPS) with proteasome inhibitors has indicated possible efficacy for the treatment of neuro-inflammatory disorders . We used 2-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to identify proteins affected by rifampicin in activated microglia. We uncovered that the expression of 26S protease regulatory subunit 7 (MSS1) was reduced. MSS1 localizes to both the nucleus and the cytoplasm. It functions as a chaperone-like subunit in the 19S regulatory complex and participates in intracellular proteasome events. MSS1 is an important regulatory subunit of the ubiquitin - proteasome pathway , and can activate the expression of inflammatory genes, but its molecular mechanisms remain elusive. .According to the pre-experimental results, we speculate that the regulation of the expression of MSS1 may become a potential target for prevention and treatment of PD. Taken together, we clarify that the regulation of the expression of MSS1 induced the inhibition of nuclear factor-kappa B activation by vitro and in vivo experiments which can lead to a lower level of pro-inflammatory cytokines, and this molecular mechanisms play an important role in the PD. Thus, we provide new perspective and target of the prevention and treatment of PD.

脑内小胶质细胞的活化引起的神经炎症是帕金森病（Parkinson's Disease，PD）重要的发病机制之一。通过抑制、减轻神经炎症反应为靶点改善和阻断PD的进展，是防治PD的一个有效新策略。我们前期研究发现：利福平可通过抑制TLR-4介导的NF-κB通路的激活，减轻神经炎症从而发挥神经元的保护作用。我们进一步运用蛋白质组学技术研究发现：利福平可抑制MSS1的表达，而MSS1是泛素-蛋白酶体途径重要的调节亚基，可以启动相关炎症基因的表达，但其作用的分子机制尚未阐明。根据预实验结果我们推测：调控MSS1的表达可能成为防治PD的一个潜在靶点。因此，本研究拟通过体内、外实验，阐明调控MSS1的表达致NF-κB的活化受抑制从而引起促炎症细胞因子水平的降低在PD疾病中发挥重要作用的分子机制，这将为PD的防治提供全新的视角和靶点。

脑内小胶质细胞的活化引起的神经炎症是帕金森病（Parkinson’s Disease，PD）重要的发病机制之一。通过抑制、减轻神经炎症反应为靶点改善和阻断PD的进展，是防治PD的一个有效新策略。我们前期研究发现：利福平可通过抑制TLR-4介导的NF-κB通路的激活，减轻神经炎症从而发挥神经元的保护作用。我们进一步运用蛋白质组学技术研究发现：利福平可抑制MSS1的表达，而MSS1是泛素-蛋白酶体途径重要的调节亚基，可以启动相关炎症基因的表达，但其作用的分子机制尚未阐明。. 本研究通过体内、外实验，阐明调控MSS1的表达致NF-κB的活化受抑制从而引起促炎症细胞因子水平的降低在PD疾病中发挥重要作用的分子机制。研究证实，(一）siRNA干扰MSS1基因后能够明显增加LPS刺激BV2小胶质细胞IκBα的表达。siRNA干扰MSS1基因后能够明显减少LPS刺激BV2小胶质细胞iNOS、COX-2的表达。（二）利福平通过抑制TLR4对LPS刺激神经元与小胶质细胞共培养体系中神经元凋亡具有抑制作用。（三）通过建立稳定的小胶质细胞与神经元共培养的体系，发现下调MSS1的表达后对小胶质细胞活化介导的神经元损伤具有保护作用；（四）以雄性SD大鼠复制PD动物模型，将MSS1 siRNA片段脑立体定向注射抑制MSS1的表达，发现对PD模型鼠行为学具有改善作用。. 本课题研究阐明：调控MSS1是PD一个潜在的治疗靶点。抑制MSS1的表达通过抑制TLR-4介导的泛素化的IκBα的降解来调控NF-κB的活化，从而调节炎症细胞因子的释放，进而抑制神经炎症和减轻炎症反应，改善和阻断PD疾病的进展。