Neuroprotection of L-dopa treatment inducing IL-13 expression in cerebral ischemia

초록

Stroke is a leading cause of death and disability worldwide. When a stroke occurs various immune cells e.g. T cells are infiltrated, and brain cells such as neurons died. Levodopa (L-dopa), a crucial neurotransmitter for motor learning and the development of motor abilities, has recently attracted more attention since they help with motor recovery following stroke. Several clinical trials showed that the use of L-dopa showed positive outcomes. However, the molecular mechanisms are not fully investigated. Here, we measured increased amphetamine-induced rotation at one and two weeks after tMCAO (transient middle cerebral artery occlusion) which were consistent with the decreased dopamine levels in the brain. When we administered L-dopa one week after tMCAO, the amphetamine-induced rotation is reduced and dopamine levels were increased. Intriguingly we found increased IL-13 in the brain after tMCAO, which was further increased by injection with L-dopa. To investigate the function of IL-13 in tMCAO, we neutralized the IL-13 expression using anti-IL-13 antibodies and found that decreased dopamine levels and increased amphetamine-induced rotation. Furthermore, we identified that L-dopa can increase IL-13 expression in regulatory T cells using in vitro culture system. In summary, L-dopa can probably promote motor recovery by inducing IL-13 regulatory T cells.