Background and purpose: T cell activation, which is detrimental to the ischemic brain, requires metabolic reprogramming to meet the increased fuel demanding. ACC1 is an enzyme catalyzing the carboxylation of acetyl-CoA to malonyl CoA, a key substrate in the glycolytic-lipogenic pathway, which is extremely critical for T cell differentiation and phenotype polarization. We tested the hypothesis that pharmacologically inhibiting the enzyme ACC1 early after stroke may restrain T cell activation and protect against cerebral ischemic injury.
Methods: Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 60 minutes in C57/B6 mice. Soraphen A, the specific pharmacological inhibitor of ACC1 was administered at 1 hour after reperfusion at the dose of 1mg/kg, 5mg/kg, 10mg/kg and 50mg/kg intraperitoneally. Infarct volume was assess at 3 days after surgery by staining with 2,3,5-triphenyltetrazolium chloride. Behavior assessments, such as body proprioception, climbing, forelimb walking, lateral turning, foot fault and adhesive removal were examined at 3, 5, 7, 14, 21 and 28 days after stroke. T cell infiltration into the ischemic brain was examined by immunofluorescent staining.
Results: Mice treated with 5mg/kg or 10mg/kg soraphen A exhibited significantly smaller infarct volume at 3 days after stroke. 5mg/kg was chosen as the dose for further experiments. Soraphen A treatment improved the overall neurological assessment and enhanced the performance of mice in adhesive removal test and grid walking test. Soraphen A treatment significantly attenuated the CD3+ T cell and Gr-1+ neutrophil infiltration in the ischemic mice brain at 3 days after surgery.
Conclusion: Pharmacological inhibition of T cell activation by soraphen A is protective against cerebral ischemic injury and may represent a novel strategy for stroke therapy.