Abstract：
Ischemic stroke induces a debilitating neurological insult, where inflammatory processes contribute greatly to the expansion and growth of the injury. Receptor-interacting protein kinase 2 (RIPK2) is most well-known for its role as the obligate kinase for NOD1/2 pattern recognition receptor signaling and is implicated in the pathology of various inflammatory conditions. Compared to a sham-operated control, ischemic stroke resulted in a dramatic increase in the active, phosphorylated form of RIPK2, indicating that RIPK2 may be implicated in the response to stroke injury. Here, we assessed the effects of pharmacological inhibition of RIPK2 to improve post-stroke outcomes in mice subjected to experimental ischemic stroke. We found that treatment at the onset of reperfusion with a RIPK2 inhibitor, which inhibits the phosphorylation and activation of RIPK2, resulted in marked improvements in post-stroke behavioral outcomes compared to the vehicle-administered group assessed 24 h after stroke. RIPK2 inhibitor-treated mice exhibited dramatic reductions in infarct volume, concurrent with reduced damage to the blood-brain barrier, as evidenced by reduced levels of active matrix metalloproteinase-9 (MMP-9) and leakage of blood-borne albumin in the ipsilateral cortex. To explore the protective mechanism of RIPK2 inhibition, we next pretreated mice with RIPK2 inhibitor or vehicle and examined transcriptomic alterations occurring in the ischemic brain 6 h after stroke. We observed a dramatic reduction in neuroinflammatory markers in the ipsilateral cortex of the inhibitor-treated group while also attaining a comprehensive view of the vast transcriptomic alterations occurring in the brain with inhibitor treatment through bulk RNA-sequencing of the injured cortex. Overall, we provide significant novel evidence that RIPK2 may represent a viable target for post-stroke pharmacotherapy and potentially other neuroinflammatory conditions.
摘要：
缺血性中风会导致神经损伤，炎症过程极大地促进了损伤的扩展和生长。受体相互作用蛋白激酶2（RIPK2）以其作为NOD1/2模式识别受体信号传导的专性激酶的作用而闻名，并与各种炎症的病理学有关。与假手术对照相比，缺血性卒中导致活动期急剧增加，磷酸化形式的RIPK2，表明RIPK2可能与中风损伤的反应有关。这里,我们评估了RIPK2的药理学抑制作用对实验性缺血性卒中小鼠卒中后结局的改善作用.我们发现在再灌注开始时用RIPK2抑制剂治疗，抑制RIPK2的磷酸化和激活,与在卒中后24小时评估的载体给药组相比,导致卒中后行为结局显著改善.RIPK2抑制剂治疗的小鼠显示梗死体积显著减少，同时减少对血脑屏障的损伤，同侧皮质中活性基质金属蛋白酶-9（MMP-9）水平降低和血源性白蛋白渗漏证明了这一点。探讨RIPK2抑制的保护机制,接下来,我们用RIPK2抑制剂或载体对小鼠进行预处理,并检查卒中后6小时缺血性脑中发生的转录组改变.我们观察到抑制剂治疗组的同侧皮质中的神经炎标记物的显着减少，同时还通过对受损皮质的大量RNA测序，对抑制剂治疗在大脑中发生的巨大转录组改变进行了全面的观察。总的来说,我们提供了重要的新证据,表明RIPK2可能是卒中后药物治疗和潜在的其他神经炎性疾病的可行靶点.
