Peiminine-Induced Selective Autophagy of AIM2 Inflammasomes Rescues Cerebral Ischemic Injury

Inflammasome hyperactivation drives neuroinflammation following cerebral ischemia, yet pharmacological strategies inducing their selective clearance remain largely unexplored. Selective autophagy holds particular promise as a therapeutic strategy by eliminating detrimental substrates while avoiding the side effects of excessive autophagy. However, few compounds are currently available to achieve this selective regulation.

Transient middle cerebral artery occlusion was used to screen the active compounds from Fritillaria, combined with TTC staining and neurological scores. Postischemic apoptosis, inflammation, and autophagy were evaluated via immunofluorescence and immunoblotting. RNA sequencing of the ischemic penumbra revealed transcriptomic changes. Cell-specific effects were confirmed using cell coculture and glial-deficient transgenic mice. Compound-inflammasome interactions were studied by biolayer interferometry and molecular dynamics.

Peiminine demonstrates robust neuroprotection after cerebral ischemia. RNA sequencing and immunoblotting analyses revealed that peiminine markedly suppresses postischemic inflammation. Correspondingly, peiminine exerts its neuroprotective effect primarily through actions on microglia but not astrocytes, indicated by neuron-glia cocultures and transgenic mice models with targeted cell-type depletion. Biolayer interferometry and molecular dynamics simulations indicated that peiminine selectively binds to AIM2, showing no interaction with NLRP1 (NLR family pyrin domain containing 1) and approximately 100-fold higher affinity compared with NLRP3. Notably, peiminine specifically activates the selective autophagic clearance of AIM2 inflammasomes within microglia without increasing overall autophagic flux or affecting other inflammasomes. Selective blockage of autophagy in microglia abolished the neuroprotective effect of peiminine.

Peiminine exhibited robust neuroprotection against cerebral ischemia by selectively promoting the autophagic clearance of AIM2 inflammasomes to mitigate neuroinflammation.