Danshensu derivative mitigate cerebral ischemia-reperfusion injury via the PI3K-AKT-CREB signaling pathway

Danshensu (DSS) is one of the water-soluble components extractable from the traditional Chinese medicine Salvia miltiorrhiza Bge., exhibiting pharmacological effects such as promoting blood circulation, dilating coronary arteries, and improving cerebral blood flow. The Danshensu derivative (OZD-1) obtained through the derivatization of DSS is a potential multi-target drug for the central nervous system, however, its mechanism of action against cerebral ischemia-reperfusion injury (CIRI) remains unclear.

Systematically investigating the therapeutic potential and mechanisms of action of Danshensu derivative against cerebral ischemia-reperfusion injury.

Rat brain microvascular endothelial cells (RBMVECs) were cultured in vitro to establish an oxygen-glucose deprivation/reoxygenation (OGD/R) injury model. Groups included a control group, an OGD/R model group, and OZD-1 low-dose (12.5 μmol/L), medium-dose (25 μmol/L), and high-dose (50 μmol/L) groups. Cell viability, migration capacity, and vascular lumen formation were assessed using the CCK-8 assay, cell scratch assay, and matrigel matrix gel assay, respectively. In vivo, a transient middle cerebral artery occlusion (tMCAO) model was established in rats. Animals were randomly divided into the sham, model, OZD-1 (35, 70, 140 mg/kg), Edaravone (Eda), and DSS groups. Daily oral administration was performed post-surgery for 14 consecutive days. Tissue pathology staining, behavioral tests, and regional cerebral blood flow imaging assessed brain tissue damage, cognitive function, and ischemic side cerebral blood flow recovery, respectively. Transcriptome sequencing analyzed differential gene expression and pathway enrichment patterns. Western blot detection measured expression levels of proteins related to the PI3K-AKT-CREB signaling pathway, phosphoproteins, downstream apoptosis-related proteins, and CD31, CD34, and VEGFA proteins.

In vitro experiments demonstrated that OZD-1 dose-dependently enhanced the viability of RBMVECs following OGD/R injury, significantly improving cell migration and luminal formation capabilities. In vivo studies revealed that compared to the model group, rats in all OZD-1 dosage groups exhibited markedly improved cognitive function, significantly restored cerebral blood flow in the ischemic hemisphere, and substantially reduced pathological brain tissue damage. Transcriptome sequencing results indicated significant enrichment of genes associated with the PI3K-AKT signaling pathway following OZD-1 intervention. Western blot experiments confirmed that OZD-1 significantly upregulates the phosphorylation levels of proteins related to the PI3K-AKT-CREB signaling pathway in OGD/R-injured cells and brain tissue from tMCAO rats, thereby promoting VEGFA-mediated angiogenesis and inhibiting apoptosis. To further verify pathway involvement, in vitro inhibition experiments were performed in RBMVECs using the PI3K inhibitor LY294002 and CREB inhibitor 666-15. These inhibitors abolished the OZD-1-induced upregulation of p-PI3K, p-AKT, and p-CREB, and reversed its protective effects on cell viability, migration, and tube formation. These results confirm that OZD-1 protects vascular endothelial cells directly via activating the PI3K-AKT-CREB pathway.

OZD-1 exhibits significant neuroprotective effects against CIRI in rats, improving cognitive function, promoting vascular regeneration in ischemic areas, repairing damaged RBMVECs, and reducing apoptosis. Its mechanism of action is associated with the activation of the PI3K-AKT-CREB-VEGFA signaling pathway.