CABIMER, Andalusian Center for Molecular Biology and Regenerative Medicine, Seville, Spain.
PLoS One. 2013 Nov 13;8(11):e79160. doi: 10.1371/journal.pone.0079160. eCollection 2013.
In recent years, it has become accepted that α-synuclein (αSyn) has a key role in the microglia-mediated neuroinflammation, which accompanies the development of Parkinson's disease and other related disorders, such as Dementia with Lewy Bodies and Alzheimer's disease. Nevertheless, the cellular and molecular mechanisms underlying its pathological actions, especially in the sporadic forms of the diseases, are not completely understood. Intriguingly, several epidemiological and animal model studies have revealed a link between certain microbial infections and the onset or progression of sporadic forms of these neurodegenerative disorders. In this work, we have characterized the effect of toll-like receptor (TLR) stimulation on primary murine microglial cultures and analysed the impact of priming cells with extracellular wild-type (Wt) αSyn on the subsequent TLR stimulation of cells with a set of TLR ligands. By assaying key interleukins and chemokines we report that specific stimuli, in particular Pam3Csk4 (Pam3) and single-stranded RNA40 (ssRNA), can differentially affect the TLR2/1- and TLR7-mediated responses of microglia when pre-conditioned with αSyn by augmenting IL-6, MCP-1/CCL2 or IP-10/CXCL10 secretion levels. Furthermore, we report a skewing of αSyn-primed microglia stimulated with ssRNA (TLR7) or Pam3 (TLR2/1) towards intermediate but at the same time differential, M1/M2 phenotypes. Finally, we show that the levels and intracellular location of activated caspase-3 protein change significantly in αSyn-primed microglia after stimulation with these particular TLR agonists. Overall, we report a remarkable impact of non-aggregated αSyn pre-sensitization of microglia on TLR-mediated immunity, a phenomenon that could contribute to triggering the onset of sporadic α-synuclein-related neuropathologies.
近年来，人们已经接受了α-突触核蛋白（αSyn）在小胶质细胞介导的神经炎症中的关键作用，这种炎症伴随着帕金森病和其他相关疾病的发展，如路易体痴呆和阿尔茨海默病。然而，其病理作用的细胞和分子机制，特别是在疾病的散发性形式中，还不完全清楚。有趣的是，几项流行病学和动物模型研究表明，某些微生物感染与这些神经退行性疾病的散发性形式的发病或进展之间存在联系。在这项工作中，我们描述了 Toll 样受体（TLR）刺激对原代小鼠小胶质细胞培养物的影响，并分析了用细胞外野生型（Wt）αSyn 预刺激细胞对随后用一组 TLR 配体刺激细胞的影响。通过检测关键的白细胞介素和趋化因子，我们报告说，特定的刺激物，特别是 Pam3Csk4（Pam3）和单链 RNA40（ssRNA），在通过增加 IL-6、MCP-1/CCL2 或 IP-10/CXCL10 分泌水平用 αSyn 预条件化后，可以有差异地影响 TLR2/1 和 TLR7 介导的小胶质细胞反应。此外，我们报告说，用 ssRNA（TLR7）或 Pam3（TLR2/1）刺激的αSyn 预刺激小胶质细胞向中间但同时又不同的 M1/M2 表型倾斜。最后，我们发现在用这些特定的 TLR 激动剂刺激后，αSyn 预刺激的小胶质细胞中激活的 caspase-3 蛋白的水平和细胞内位置发生了显著变化。总的来说，我们报告了非聚集的αSyn 预致敏小胶质细胞对 TLR 介导的免疫的显著影响，这种现象可能有助于触发散发性α-突触核蛋白相关神经病理学的发病。
