Tetrahydroxy stilbene glucoside promotes mitophagy and ameliorates neuronal injury after cerebral ischemia reperfusion via promoting USP10 mediated YBX1 stability.

Abstract

Tetrahydroxy stilbene glucoside (TSG) from polygonum multiflorum exerts neuroprotective effects after ischemic stroke. We explored whether TSG improved ischemic stroke injury via PINK1/Parkin-mediated mitophagy. Oxygen glucose deprivation/reoxygenation (OGD/R) in vitro model and middle cerebral artery occlusion (MCAO) rat model were established. Cerebral injury was assessed by neurological score, hematoxylin and eosin staining, TTC staining and brain water content. Apoptosis, cell viability and mitochondrial membrane potential were assessed by flow cytometry, CCK-8 and JC-1 staining, respectively. Co-localization of LC3-labeled autophagosomes with LAMP2-labeled lysosomes or Tomm20-labeled mitochondria was observed with fluorescence microscopy. Ubiquitination level was determined using ubiquitination assay. The interaction between molecules was validated by co-immunoprecipitation and GST pull-down. We found that TSG promoted mitophagy and improved cerebral I/R damage in MCAO rats. In OGD/R-subjected neurons, TSG promoted mitophagy, repressed neuronal apoptosis, upregulated Y-box binding protein-1 (YBX1) and activated PINK1/Parkin signaling. TSG upregulated ubiquitin-specific peptidase 10 (USP10) to elevate YBX1 protein. Furthermore, USP10 inhibited ubiquitination-dependent YBX1 degradation. USP10 overexpression activated PINK1/Parkin signaling and promoted mitophagy, which were reversed by YBX1 knockdown. Moreover, TSG upregulated USP10 to promote mitophagy and inhibited neuronal apoptosis. Collectively, TSG facilitated PINK1/Parkin pathway mediated mitophagy by upregulating USP10/YBX1 axis to ameliorate ischemic stroke.Significance Statement: Ischemic stroke is one of leading causes of disability and death worldwide. Previous studies have demonstrated a neuroprotective role of TSG in ischemic stroke, while the underlying mechanism is still not fully understood. Here, this study confirmed that TSG relieved cerebral I/R injury in vivo and in vitro via facilitated PINK1/Parkin-mediated mitophagy. In addition, we further identified the molecular mechanism by which TSG regulates mitochondrial autophagy. Our study provided new insights into the protective role TSG in ischemic stroke via regulating mitophagy.