Deferoxamine alleviates brain ischemia/reperfusion injury through decreasing LAG-3 and α-Syn expression

Ischemic stroke is characterized by brain tissue iron accumulation. Alpha-synuclein (α-Syn) is a neuronal protein, its overexpression in ischemic stroke triggers apoptosis. Lymphocyte activation gene-3 (LAG-3), a receptor for α-Syn, enhances its neurotoxic effects. It is split from the cell membrane forming soluble LAG-3 (sLAG-3) in the bloodstream. The expression of LAG-3 in the brain, its relation to iron and α-Syn, as well as the association between serum sLAG-3 levels, iron, α-Syn, and stroke severity remains poorly understood. A case-control study was generated involving 24 patients with acute ischemic stroke and 24 healthy controls. In addition, an experimental study was designed involving 24 Wistar-albino rats. We randomly assigned rats to three groups: sham-operated, brain ischemia, and deferoxamine-treated ischemic rats. Ischemia decreased serum levels of iron, while increased serum levels of α-Syn and sLAG-3. Significant diagnostic performance of serum α-Syn and sLAG-3 was determined using the ROC curve (AUC = 0.962, 83.33% sensitivity, and 95.83% specificity for α-Syn; AUC = 0.755 with 62.50% sensitivity and 87.50% specificity for LAG-3). In rats, ischemia elevated brain tissue iron, α-Syn, and LAG-3 which were reduced following deferoxamine treatment. In conclusion, brain ischemia is associated with iron accumulation that promotes α-Syn expression and aggregation, potentially through increasing LAG-3 expression which improved after deferoxamine injection. In addition, this study illuminates the future beneficial targeting of LAG-3 in brain ischemia.