Extracellular prolyl oligopeptidase derived from activated microglia is a potential neuroprotection target
Extracellular prolyl oligopeptidase derived from activated microglia is a potential neuroprotection target
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DOI：
10.1111/bcpt.13094
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发表时间：
2019-01-01
影响因子：
3.1
通讯作者：
Jalkanen, Aaro J.
中科院分区：
文献类型：
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作者：
Natunen, Teemu A.;Gynther, Mikko;Jalkanen, Aaro J.
脯氨酸寡肽酶（Prolyl oligopeptidase， PREP）是一种存在于大脑和外周的丰富的肽酶，但其生理功能在很大程度上仍是未知的。最近的研究结果指出PREP在炎症过程中的作用。本研究评估了在脂多糖（LPS）和干扰素γ (IFN γ)诱导的神经炎症条件下，小鼠原代皮质神经元、小胶质细胞和星形胶质细胞以及永生化小胶质BV-2细胞培养物的细胞和细胞外PREP活性。此外，我们在基于原代皮质神经元和活化的BV-2细胞共培养的神经炎症模型中评估了特异性PREP抑制剂KYP-2047的神经保护作用。炎症损伤降低了细胞内和细胞外的PREP活性，特别是在小胶质细胞中，这表明活化的小胶质细胞分泌活性PREP。靶向蛋白质组学方法显示，在BV-2细胞生长培养基中，PREP蛋白水平上调，而LPS+IFN γ后，粗膜结合的PREP蛋白水平下调。在BV-2细胞和原代神经元共培养中，炎症后细胞外PREP活性也有所增加。kypp -2047 （10 μ mol/L）显著保护神经元免受小胶质细胞毒性，并降低促炎细胞因子肿瘤坏死因子α的水平。总之，这些数据表明小胶质PREP在炎症过程中的细胞外作用。在神经炎症期间抑制PREP是神经保护的潜在目标。因此，PREP抑制剂可能为治疗包括帕金森病和阿尔茨海默病在内的炎症成分的神经退行性疾病提供一种新的治疗方法。
Prolyl oligopeptidase (PREP) is an abundant peptidase in the brain and periphery, but its physiological functions are still largely unknown. Recent findings point to a role for PREP in inflammatory processes. This study assessed the cellular and extracellular PREP activities in cultures of mouse primary cortical neurons, microglial cells and astrocytes, and immortalized microglial BV-2 cells under neuroinflammatory conditions induced by lipopolysaccharide (LPS) and interferon gamma (IFN gamma). Furthermore, we evaluated the neuroprotective effect of a specific PREP inhibitor, KYP-2047, in a neuroinflammation model based on a coculture of primary cortical neurons and activated BV-2 cells. The inflammatory insult reduced intracellular and increased extracellular PREP activity specifically in microglial cells, suggesting that activated microglia excretes active PREP. A targeted proteomics approach revealed up-regulation in PREP protein levels in BV-2 cell growth medium but down-regulation in crude membrane-bound PREP after LPS+IFN gamma. In the coculture of BV-2 cells and primary neurons, an increase in extracellular PREP activity was also detected after inflammation. KYP-2047 (10 mu mol/L) significantly protected neurons against microglial toxicity and reduced the levels of the pro-inflammatory cytokine tumour necrosis factor alpha. In conclusion, these data point to an extracellular role for microglial PREP in the inflammatory process. Inhibition of PREP during neuroinflammation is a potential target for neuroprotection. Thus, PREP inhibitors may offer a novel therapeutic approach for the treatment of neurodegenerative disorders with an inflammatory component including Parkinson's and Alzheimer's diseases.