Celastrol Exerts Neuroprotective Effect via Directly Binding to Hmgb1 Protein in Cerebral Ischemic Reperfusion

Abstract Background: Celastrol is one of the early isolated and identified chemical constituents from Tripterygium wilfordii Hook.f.. Based upon the celastrol probe that maintained the bioactivity of the parent compound, the targets of celastrol in cerebral ischemic reperfusion (I/R) were comprehensively analyzed by quantitative chemical proteomics method.Methods: We constructed primary cortical neurons model of oxygen-glucose deprivation (OGD) and rat model of middle cerebral artery occlusion (MCAO) to detect the targets of celastrol in cerebral I/R. Combining with various experimental methods such as tandem mass tags (TMT) labeling, mass spectrometry and cellular thermal shift assay (CETSA), we revealed the directly binding cellular targets of celastrol.Results: We uncovered that celastrol inhibited pro-inflammatory activity of high mobility group protein 1 (HMGB1) by directly binding to it and then blocking the binding of HMGB1 to its inflammatory receptors in the microenvironment of ischemic and hypoxia. In addition, celastrol rescued neurons from OGD injury in vitro and decreased cerebral infarction in vivo by targeting HSP70 and NF-κB.Conclusion: Celastrol exhibited neuroprotective and anti-inflammatory effects via targeting HSP70 and NF-κB and directly binding to HMGB1 in cerebral ischemic reperfusion injury.