Developing cytoskeletal-based interventions for adolescent-onset depression

项目总结 青春期起病的抑郁症是一种特别致命的抑郁症，因为对 抗抑郁治疗。此外，抑郁症在青春期和青春期的表现是 一生中抑郁复发的风险更高。因此，迫切需要 开发适合青少年大脑的新型抗抑郁药物。 青春期是神经发育的关键时期。它是由结构和突触定义的 前额叶皮质(PFC)内的成熟和重组。在这段时间里，树突棘，初级的 兴奋性突触的位置，经过修剪、精炼和稳定。对动物模型的研究表明 结构的稳定性赋予了对抑郁症等神经精神疾病的韧性。 使用条件性基因敲除小鼠的研究表明，神经成熟和 在青春期稳定的是β1-整合素受体。β1-整合素信号通路抑制Rho Kinase-II (ROCKII)促进肌动蛋白细胞骨架稳定的活性。我已经证明了ROKII抑制剂， 法舒地尔对青春期小鼠有类似抗抑郁药的疗效，但对成年小鼠没有。法舒地尔还能修剪树突棘 同时增加青少年PFC中突触标志物的表达，表明它增强了典型的树突状细胞 脊椎修剪和加强突触。我假设法舒地尔与内源性β-1-整合素- 调节青春期的信号事件，以发挥其结构性和类似治疗的好处。 目标1将测量β1整合素受体下游蛋白的表达和活性水平 健康发育的PFC是确定β1整合素治疗靶向可行性的关键一步 青少年中的信号级联反应。接下来，AIM 2将使用病毒介导的基因沉默，共聚焦荧光 显微镜和3D树突状脊柱重建，以验证法舒地尔对 青春期PFC内树突棘的成熟和修剪是由于与 内源性β-1-整合素介导的信号转导及对ROCKII的协同抑制 目的3将评估增强β1-整合素级联信号的抗抑郁药样疗效和 将检验这一假设，即法舒地尔的行为疗效也归因于与内源性 β1-整合素介导的抑制ROCKII的信号转导我还将评估DPH的抗抑郁药样疗效。 精氨酸激酶的新型激活剂，β1-整合素的主要底物。最后，我将测试是否具有站点选择性 β-1-整合素基因敲除在青春期患者中诱导了抑郁样表型。 这些实验的积极结果将表明β1-整合素信号事件可能是一种可行的 为青少年突发性抑郁症制定新的干预策略的目标，并将确定 β-1-整合素介导的信号在青春期情绪调节中的弹性因素。

PROJECT SUMMARY Adolescent-onset depression is a particularly virulent form of depression due to increased resistance to antidepressant treatment. Furthermore, the manifestation of depression in adolescence and young adulthood is associated with higher risk for depression recurrence across the lifespan. As a result, there is a dire need for the development of novel antidepressants that are suitable for the adolescent brain. Adolescence represents a critical period of neurodevelopment. It is defined by structural and synaptic maturation and reorganization within the prefrontal cortex (PFC). During this time, dendritic spines, the primary site of excitatory synapses, are pruned, refined, and stabilized. Research in animal models suggests that structural stability confers resilience to neuropsychiatric diseases, such as depression. Research using conditional knockout mice indicates that one critical regulator of the neural maturation and stabilization in adolescence is the β1-integrin receptor. The β1-integrin signaling pathway inhibits Rho Kinase-II (ROCKII) activity to promote stabilization of the actin cytoskeleton. I have shown that the ROCKII inhibitor, fasudil, has antidepressant-like efficacy in adolescent, but not adult, mice. Fasudil also prunes dendritic spines while increasing synaptic marker expression in the adolescent PFC, suggesting that it enhances typical dendritic spine pruning and strengthens synapses. I hypothesize that fasudil converges with endogenous β1-integrin- mediated signaling events during adolescence to exert its structural and therapeutic-like benefits. Aim 1 will measure the expression and activity levels of proteins downstream of the β1-integrin receptor in the healthy developing PFC, a critical step in determining the feasibility of therapeutically targeting the β1-integrin signaling cascade in adolescents. Next, Aim 2 will use viral-mediated gene silencing, confocal fluorescence microscopy, and 3D dendritic spine reconstruction to test the hypothesis that fasudil’s beneficial impact on the maturation and pruning of dendritic spines in the PFC during adolescence is due to convergence with endogenous β1-integrin-mediated signaling and synergistic inhibition of ROCKII. Aim 3 will evaluate the antidepressant-like efficacy of enhancing signaling of the β1-integrin cascade and will test the hypothesis that the behavioral efficacy of fasudil is also attributable to convergence with endogenous β1-integrin-mediated signaling to inhibit ROCKII. I will also assess the antidepressant-like efficacy of DPH, a novel activator of Arg kinase, a primary β1-integrin substrate in the PFC. Lastly, I will test whether site-selective β1-integrin knockdown in the adolescent PFC induces a depressive-like phenotype. Positive outcomes from these experiments will indicate that β1-integrin signaling events may be a viable target in the development of novel intervention strategies for adolescent-emergent depression and will identify β1-integrin-mediated signaling as a resiliency factor in mood regulation in adolescence.