Endothelial -targeted CD39 is protective in a mouse model of global forebrain ischaemia

Global ischemic brain injury occurs after cardiac arrest or prolonged hypotensive episodes following surgery or trauma. It causes significant neurological deficits even after successful re-establishment of blood flow. It is the primary cause of death in 68% of inpatient and 23% of out-of-hospital cardiac arrest cases, but there are currently no treatments. Endothelial activation and dysfunction impairing small vessel blood flow is the cause of brain damage. Purinergic signaling is an endogenous molecular pathway, where CD39 and CD73 catabolize extracellular adenosine triphosphate (eATP) to adenosine. After ischemia, eATP is released, triggering thrombosis and inflammation. In contrast, adenosine is anti-thrombotic, protects against oxidative stress, and suppresses the immune response. Our group developed a bifunctional compound – anti-VCAM-CD39 that targets dysregulated endothelium and promotes adenosine generation at the infarct site, localising antithrombotic and anti-inflammatory effects of CD39. We investigated whether anti-VCAM-CD39 could improve outcome in a murine model of global ischaemia caused by dual carotid artery ligation (DCAL). Test drugs anti-VCAM-CD39 and controls were given 3h after 30min ischaemia. Assessments at 24h included neurological function, infarct volume, perfusion, albumin extravasation to assess blood-brain barrier (BBB) permeability. We showed that there was an overall improvement in neurological deficit in αVCAM-CD39-treated mice after DCAL. MRI revealed that these mice had significantly smaller infarcts and reduced apoptotic activity on the side of permanent occlusion, compared to saline treated mice. There was reduced albumin extravasation in treated mice after DCAL, suggesting anti-VCAM-CD39 conferred neuroprotection in the brain through preservation of blood brain barrier (BBB) permeability. In vitro findings confirmed that αVCAM-CD39-mediated adenosine protected against hypoxia-induced endothelial cell death. anti-VCAM-CD39 is a novel therapeutic that can promote neuroprotection, reduce tissue damage and inflammation in the brain after hypoxic brain injury in mice. These findings suggest that anti-VCAM-CD39 could be a new avenue of cardiac arrest therapy and could potentially be used in other cerebrovascular diseases where endothelial dysfunction is a constant underlying pathology.