Intravenous tenecteplase bridging reperfusion ameliorates cerebral ischemia/reperfusion injury by improving microvascular circulation in rats

Background Endovascular treatment (EVT) alone was not demonstrated to be non-inferior to intravenous alteplase bridging EVT in acute large vessel occlusion (LVO) stroke. Using cerebral ischemia/reperfusion (I/R) injury model, intravenous tenecteplase (TNK) was administrated after ischemia followed by reperfusion at various time points. Objectives To investigate whether intravenous TNK bridging EVT vs EVT alone could improve I/R injury, and this effect may be associated with the time from TNK to reperfusion. Methods Rats received intravenous TNK (1.4 mg/kg) or vehicle (sterile water) 1.0 hour after middle cerebral artery occlusion (MCAO), followed by reperfusion after 0.5 or 1.0 hour following TNK. Neurological deficit scores, infarct volume, and brain edema were measured at 24 hours after MCAO. Microthrombi were determined by immunofluorescence staining for CD31 + /fibrinogen + and CD31 + /thrombocyte + . Inflammatory cell infiltration in the ischemic brain region was determined by flow cytometry. Results Compared with vehicle, TNK significantly reduced neurological deficit scores, brain infarction, neuro-inflammation, and blood-brain barrier (BBB) disruption, and significantly reduced intravascular fibrin and platelet deposition, and brain inflammatory cell infiltration in penumbra of I/R rats. Furthermore, a better beneficial trend was found in TNK bridging reperfusion at 0.5 hour after TNK compared with TNK bridging reperfusion at 1.0 hour after TNK. Conclusions Our results demonstrate that intravenous TNK bridging reperfusion produced neuroprotective action through dissolving microvascular thrombus and alleviating inflammatory cell infiltration to improve microcirculation, with the result of maintaining BBB integrity and inhibiting neuroinflammation, and the neuroprotective benefit may be associated with the time from TNK to reperfusion.