Moreton Niamh, Puzio Martina, McCormack Janet, O'Connor John J
UCD School of Biomolecular & Biomedical Science, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
UCD Research Pathology Core, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
Brain Res Bull. 2023 Dec;205:110822. doi: 10.1016/j.brainresbull.2023.110822. Epub 2023 Nov 18.
The contributions of hypoxia and oxidative stress to the pathophysiology of acute ischemic stroke are well established and can lead to disruptions in synaptic signaling. Hypoxia and oxidative stress lead to the neurotoxic overproduction of reactive oxygen species (ROS) and the stabilization of hypoxia inducible factors (HIF). Compounds such as prolyl-4-hydroxylase domain enzyme inhibitors (PHDIs) have been shown to have a preconditioning and neuroprotective effect against ischemic insults such as hypoxia, anoxia, oxygen glucose deprivation (OGD) or HO. Therefore, this study explored the effects of two PHDIs, JNJ-42041935 (10 µM) and roxadustat (100 µM) on cell viability using organotypic hippocampal slice cultures. We also assessed the effects of these compounds on synaptic transmission during and post hypoxia, OGD and HO application in isolated rat hippocampal slices using field recording electrophysiological techniques and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit trafficking using immunohistochemistry. Our organotypic data demonstrated a protective role for both inhibitors, where slices had significantly less cell death post anoxia and OGD compared to controls. We also report a distinct modulatory role for both JNJ-42041935 and roxadustat on fEPSP slope post hypoxia and OGD but not HO. In addition, we report that application of roxadustat impaired long-term potentiation, but only when applied post-hypoxia. This inhibitory effect was not reversed with co-application of the cyclin-dependent kinase 5 (CDK-5) inhibitor, roscovitine (10 µM), suggesting a CDK-5 independent synaptic AMPAR trafficking mechanism. Both hypoxia and OGD induced a reduction in synaptic AMPA GluA2 subunits, the OGD effect being reversed by prior treatment with both JNJ-42041935 and roxadustat. These results suggest an important role for PHDs in synaptic signaling and plasticity during episodes of ischemic stress.
缺氧和氧化应激对急性缺血性中风病理生理学的影响已得到充分证实，并且会导致突触信号传导中断。缺氧和氧化应激会导致活性氧（ROS）产生神经毒性过量以及缺氧诱导因子（HIF）稳定。脯氨酰-4-羟化酶结构域酶抑制剂（PHDIs）等化合物已被证明对缺氧、缺氧、氧糖剥夺（OGD）或全脑缺血等缺血性损伤具有预处理和神经保护作用。因此，本研究使用器官型海马脑片培养物探讨了两种PHDIs，即JNJ-42041935（10 μM）和罗沙司他（100 μM）对细胞活力的影响。我们还使用场记录电生理技术评估了这些化合物在离体大鼠海马脑片缺氧、OGD和全脑缺血期间及之后对突触传递的影响，并使用免疫组织化学评估了其对α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）受体亚基转运的影响。我们的器官型数据表明两种抑制剂均具有保护作用，与对照组相比，脑片在缺氧和OGD后的细胞死亡明显减少。我们还报告了JNJ-42041935和罗沙司他在缺氧和OGD后对场兴奋性突触后电位（fEPSP）斜率具有明显的调节作用，但对全脑缺血后则无此作用。此外，我们报告罗沙司他的应用损害了长时程增强，但仅在缺氧后应用时才会出现这种情况。细胞周期蛋白依赖性激酶5（CDK-5）抑制剂罗库溴铵（10 μM）联合应用并不能逆转这种抑制作用，这表明存在一种不依赖CDK-5的突触AMPA受体转运机制。缺氧和OGD均导致突触AMPA GluA2亚基减少，JNJ-42041935和罗沙司他预先处理均可逆转OGD的这种作用。这些结果表明PHD在缺血应激期间的突触信号传导和可塑性中起重要作用。
