PDF(Pubmed)
Abstract：
Microglial cells have been demonstrated to be significant resident immune cells that maintain homeostasis under physiological conditions. However, prolonged or excessive microglial activation leads to disturbances in the resolution of inflammation (RoI). Formyl peptide receptor 2 (FPR2) is a crucial player in the RoI, interacting with various ligands to induce distinct conformational changes and, consequently, diverse biological effects. Due to the poor pharmacokinetic properties of endogenous FPR2 ligands, the aim of our study was to evaluate the pro-resolving effects of a new ureidopropanamide agonist, compound AMS21, in hippocampal organotypic cultures (OHCs) stimulated with lipopolysaccharide (LPS). Moreover, to assess whether AMS21 exerts its action via FPR2 specifically located on microglial cells, we conducted a set of experiments in OHCs depleted of microglial cells using clodronate. We demonstrated that the protective and anti-inflammatory activity of AMS21 manifested as decreased levels of lactate dehydrogenase (LDH), nitric oxide (NO), and proinflammatory cytokines IL-1β and IL-6 release evoked by LPS in OHCs. Moreover, in LPS-stimulated OHCs, AMS21 treatment downregulated NLRP3 inflammasome-related factors (CASP1, NLRP3, PYCARD) and this effect was mediated through FPR2 because it was blocked by the FPR2 antagonist WRW4 pre-treatment. Importantly this beneficial effect of AMS21 was only observed in the presence of microglial FPR2, and absent in OHCs depleted with microglial cells using clodronate. Our results strongly suggest that the compound AMS21 exerts, at nanomolar doses, protective and anti-inflammatory properties and an FPR2 receptor located specifically on microglial cells mediates the anti-inflammatory response of AMS21. Therefore, microglial FPR2 represents a promising target for the enhancement of RoI.
摘要：
已证明小胶质细胞是在生理条件下维持体内平衡的重要驻留免疫细胞。然而,长时间或过度的小胶质细胞激活导致炎症（RoI）消退的紊乱。甲酰基肽受体2（FPR2）是RoI中至关重要的参与者，与各种配体相互作用以诱导不同的构象变化，因此,多样的生物效应。由于内源性FPR2配体的药代动力学特性较差，我们研究的目的是评估一种新型脲基丙酰胺激动剂的促解作用，化合物AMS21，在用脂多糖（LPS）刺激的海马器官型培养物（OHC）中。此外，为了评估AMS21是否通过特定位于小胶质细胞上的FPR2发挥作用，我们使用氯膦酸盐在耗竭小胶质细胞的OHC中进行了一系列实验。我们证明了AMS21的保护和抗炎活性表现为乳酸脱氢酶（LDH）水平降低，一氧化氮（NO），LPS在OHCs中引起的促炎细胞因子IL-1β和IL-6的释放。此外，在LPS刺激的OHCs中，AMS21治疗下调NLRP3炎性体相关因子（CASP1，NLRP3，PYCARD），这种作用是通过FPR2介导的，因为它被FPR2拮抗剂WRW4预处理阻断。重要的是，AMS21的这种有益作用仅在存在小胶质细胞FPR2的情况下观察到，而在使用氯膦酸盐耗尽小胶质细胞的OHC中不存在。我们的结果强烈表明，化合物AMS21发挥，以纳摩尔剂量，保护和抗炎特性以及特异性位于小胶质细胞上的FPR2受体介导AMS21的抗炎反应。因此,小胶质细胞FPR2代表了增强RoI的有希望的靶标。
