Ischemia-induced injury to neuronal processes: role of cofilin-actin rod formation

缺血性中风致残不仅是神经元死亡，也是轴突损伤所致。 以及幸存神经元的树突。缺血对这些神经元造成损伤的机制 这些过程还没有被很好地理解，也没有被很好地作为治疗的靶点来探索。粘附素-肌动蛋白 视杆细胞是cofilin-1和肌动蛋白1：1的线性聚集体，在以下条件下在神经元突起中形成 ATP耗竭或氧化应激。这些杆状突起导致神经元突起退化，在这些突起中，它们 坚持不懈。最近的研究表明，在大脑中和脑后的神经元中形成了粘连蛋白-肌动蛋白棒。 它们的形成可以从基因和药物上加以抑制。在这里，我们将 确定抑制棒形成(或加速棒溶解)可以促进的程度 卒中后轴突存活和改善运动功能。我们将使用瞬变模型和永久模型 在小鼠卒中中评估特定情况下视杆抑制对神经元突起存活的影响 缺血后的间歇。我们将评估杆状抑制对运动障碍和 用熟练的伸展任务和其他测量前肢灵巧度的方法恢复。我们的目标也是更好地 阐明炎症和亚细胞机制的作用，驱动杆状结构和连杆的形成 形成到随后的轴突变性。我们将使用亚细胞荧光探针和真正的 细胞培养准备中的时间成像，以确定棒状物为什么形成并在特定位置存留 神经元，并且即使在去除缺血刺激后也这样做；粘连蛋白-肌动蛋白的持久性 棒代表稳定的聚集体；棒的形成是否影响到 受影响的神经突起。

Disability caused by ischemic stroke results not only from neuronal death, but also from injury to axons and dendrites of surviving neurons. The mechanisms by which ischemia causes injury to these neuronal processes are not well understood, and have not been well-explored as a therapeutic target. Cofilin-actin rods are 1:1 linear aggregates of cofilin-1 and actin that form in neuronal processes under conditions of ATP depletion or oxidant stress. These rods cause degeneration of the neuronal processes in which they persist. Recent studies demonstrate that cofilin-actin rods form in neurons during and after brain ischemia, and that their formation can be suppressed genetically and pharmacologically. Here we will determine the extent to which suppression of rod formation (or accelerated rod dissolution) can promote neurite survival and improve motor function after stroke. We will use transient and permanent models of stroke in the mouse to evaluate effects of rod suppression on survival of neuronal processes at specified intervals after ischemia. We will evaluate the effects of rod suppression on motor impairment and recovery using a skilled reaching task and other measures of forelimb dexterity. We also aim to better elucidate the role of inflammation and subcellular mechanisms that drive rod formation and link rod formation to subsequent neurite degeneration. We will employ subcellular fluorescent probes and real- time imaging in cell culture preparations to determine why rods form and persist in specific locations of neurons, and do so even after the ischemic stimuli are removed; whether the persistence of cofilin-actin rods represent stable aggregates; and whether rod formation influences bioenergetic failure in the affected neurites.