Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China.
Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
Acta Pharmacol Sin. 2022 Nov;43(11):2817-2827. doi: 10.1038/s41401-022-00913-7. Epub 2022 May 2.
Progressive ischemic stroke (PIS) is featured by progressive neurological dysfunction after ischemia. Ischemia-evoked neuroinflammation is implicated in the progressive brain injury after cerebral ischemia, while Caspase-1, an active component of inflammasome, exaggerates ischemic brain injury. Current Caspase-1 inhibitors are inadequate in safety and druggability. Here, we investigated the efficacy of CZL80, a novel Caspase-1 inhibitor, in mice with PIS. Mice and Caspase-1 mice were subjected to photothrombotic (PT)-induced cerebral ischemia. CZL80 (10, 30 mg·kg·d, i.p.) was administered for one week after PT onset. The transient and the progressive neurological dysfunction (as foot faults in the grid-walking task and forelimb symmetry in the cylinder task) was assessed on Day1 and Day4-7, respectively, after PT onset. Treatment with CZL80 (30 mg/kg) during Day1-7 significantly reduced the progressive, but not the transient neurological dysfunction. Furthermore, we showed that CZL80 administered on Day4-7, when the progressive neurological dysfunction occurred, produced significant beneficial effects against PIS, suggesting an extended therapeutic time-window. CZL80 administration could improve the neurological function even as late as Day43 after PT. In Caspase-1 mice with PIS, the beneficial effects of CZL80 were abolished. We found that Caspase-1 was upregulated during Day4-7 after PT and predominantly located in activated microglia, which was coincided with the progressive neurological deficits, and attenuated by CZL80. We showed that CZL80 administration did not reduce the infarct volume, but significantly suppressed microglia activation in the peri-infarct cortex, suggesting the involvement of microglial inflammasome in the pathology of PIS. Taken together, this study demonstrates that Caspase-1 is required for the progressive neurological dysfunction in PIS. CZL80 is a promising drug to promote the neurological recovery in PIS by inhibiting Caspase-1 within a long therapeutic time-window.
进展性缺血性卒中（PIS）的特征是缺血后进行性神经功能障碍。缺血引起的神经炎症参与了脑缺血后的进行性脑损伤，而半胱天冬酶-1（Caspase-1）是炎症小体的一个活性成分，可加重缺血性脑损伤。目前的 Caspase-1 抑制剂在安全性和成药性方面都存在不足。本研究旨在探讨新型 Caspase-1 抑制剂 CZL80 在 PIS 小鼠中的疗效。采用光血栓诱导的大脑中动脉闭塞（MCAO）模型，将野生型（WT）和 Caspase-1 敲除（Caspase-1 -/-）小鼠分为假手术组和 PIS 组。在 MCAO 后给予 CZL80（10、30mg·kg·d，腹腔注射）治疗一周。在 MCAO 后第 1 天和第 4-7 天分别评估短暂性和进行性神经功能障碍（网格行走任务中的足失误和圆筒任务中的前肢对称性）。结果显示，CZL80（30mg/kg）治疗组在第 1-7 天可显著减轻进行性但不减轻短暂性神经功能障碍。此外，我们还发现，在第 4-7 天（进行性神经功能障碍发生时）给予 CZL80 治疗，对 PIS 有显著的有益作用，提示治疗时间窗延长。CZL80 给药甚至在 MCAO 后第 43 天仍可改善神经功能。在 PIS 的 Caspase-1 敲除（Caspase-1 -/-）小鼠中，CZL80 的有益作用被消除。我们发现，Caspase-1 在 MCAO 后第 4-7 天上调，主要位于激活的小胶质细胞中，与进行性神经功能缺损一致，并被 CZL80 减弱。我们还发现，CZL80 给药并未减少梗死体积，但显著抑制了梗死周边皮质中的小胶质细胞激活，提示小胶质细胞炎症小体参与了 PIS 的病理过程。综上所述，本研究表明 Caspase-1 是 PIS 进行性神经功能障碍所必需的。CZL80 通过在长治疗时间窗内抑制 Caspase-1，是一种有前景的药物，可促进 PIS 中的神经恢复。
