Laboratory of Cellular and Molecular Neuroscience (LCMN), School of Life Sciences, Faculty of Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia.
Laboratory of Neural Structure and Function (LNSF), School of Medical Sciences, (Anatomy & Histology), Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2006, Australia.
J Mol Neurosci. 2021 Mar;71(3):565-582. doi: 10.1007/s12031-020-01678-6. Epub 2020 Aug 13.
Parkinson's disease (PD) is a chronic neurodegenerative condition characterized by motor symptoms such as bradykinesia, resting tremor, and rigidity. PD diagnosis is based on medical history, review of signs, symptoms, neurological and physical examinations. Unfortunately, by the time the disease is diagnosed, dopamine (DA) neuronal loss is often extended, thereby resulting in ineffective therapies. Recent evidence suggests that neuroinflammation may be pivotal during PD onset and progression. However, suitable cellular models and biomarkers to detect early signs of neuroinflammation are still missing. In this study, we developed a well-differentiated DAergic neuronal cell line where we triggered a neuroinflammatory response to assess the temporal expression of the tissue- and urokinase plasminogen activators (tPA and uPA) and their endogenous inhibitor (PAI-1) along with that of pro-inflammatory mediators and the neuronal marker nNOS. Human neuroblastoma cells SH-SY5Y were differentiated into DAergic neuronal-like cells using a combination of 12-O-tetradecanoylphorbol-13-acetate (TPA) and serum depletion. Terminally-differentiated neurons were then exposed to lipopolysaccharide (LPS) for short (up to 24 h) or long term (up to 10 days) to mimic acute or chronic inflammation. Results demonstrated that uPA protein expression was stably upregulated during chronic inflammation, whereas the expression of nNOS protein better reflected the cellular response to acute inflammation. Additional studies revealed that the temporal induction of uPA was associated with increased AKT phosphorylation, but did not seem to involve cAMP-responsive element-binding protein (CREB) activation, nor the mitogen-activated protein kinase (MAPK) pathway. In conclusion, our in vitro data suggests that nNOS and uPA may serve as viable candidate biomarkers of acute and chronic neuroinflammation.
帕金森病（PD）是一种慢性神经退行性疾病，其特征为运动症状，如运动迟缓、静止性震颤和僵硬。PD 的诊断基于病史、体征、症状、神经和体格检查的回顾。不幸的是，当疾病被诊断出来时，多巴胺（DA）神经元的丧失往往已经很广泛，从而导致治疗效果不佳。最近的证据表明，神经炎症可能在 PD 的发病和进展中起着关键作用。然而，仍然缺乏合适的细胞模型和生物标志物来检测神经炎症的早期迹象。在这项研究中，我们开发了一种高度分化的 DA 能神经元细胞系，在该细胞系中我们引发了神经炎症反应，以评估组织型和尿激酶型纤溶酶原激活剂（tPA 和 uPA）及其内源性抑制剂（PAI-1）以及促炎介质和神经元标志物 nNOS 的时间表达。我们使用 12-O-十四烷酰佛波醇-13-乙酸酯（TPA）和血清耗竭将人神经母细胞瘤细胞 SH-SY5Y 分化为 DA 能神经元样细胞。然后，将终末分化的神经元暴露于脂多糖（LPS）中，时间短（长达 24 小时）或长（长达 10 天），以模拟急性或慢性炎症。结果表明，uPA 蛋白表达在慢性炎症期间稳定地上调，而 nNOS 蛋白的表达更好地反映了细胞对急性炎症的反应。进一步的研究表明，uPA 的时间诱导与 AKT 磷酸化的增加有关，但似乎不涉及 cAMP 反应元件结合蛋白（CREB）的激活，也不涉及丝裂原激活蛋白激酶（MAPK）途径。总之，我们的体外数据表明，nNOS 和 uPA 可能是急性和慢性神经炎症的可行候选生物标志物。
