Propofol Attenuates Inflammatory Damage via Inhibiting NLRP1-Casp1-Casp6 Signaling in Ischemic Brain Injury.

Stroke is a common cerebrovascular disease. Inflammation-induced neuronal death is one of the key factors in stroke pathology. Propofol has been shown to ameliorate neuroinflammatory injury, but the exact mechanism of its neuroprotective role remains to be fully elucidated. In the present study, we found that inflammation was activated in ischemic cortical neurons, and the expression of nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 1 (NLRP1), NLRP3 inflammasome and effectors in primary cortical neurons increased. However, we found that propofol could inhibit the increased expression of NLRP1 and NLRP3 inflammasome induced by oxygen-glucose deprivation (OGD). Furthermore, the effector molecule caspase-1 (casp1) was revealed to be the downstream target of NLRP1 and propofol repressed the activation of caspase-1 via inhibiting NLRP1 in cortical neurons. Moreover, propofol inhibits caspase-6 activation in neurons through the NLRP1-caspase-1 pathway. Once the expression of caspase6 increases, propofol reduced its neuroprotective effect in OGD-treated cortical neurons. In the stroke middle cerebral artery occlusion (MCAO) model, infusion of caspase-6 inhibitors enhanced the protective effect of propofol on infarct size and neurological function. In conclusion, our results suggest that propofol plays a neuroprotective role in stroke by inhibiting the inflammatory pathway of NLRP1-caspase-1-caspase-6. Overall, these data suggest that propofol plays a key role in the inflammatory-dependent pathway after stroke, providing an important evidence for propofol as an effective strategy for neuroprotection in stroke.