Therapeutic Irradiation and Brain Functions

项目摘要 治疗性放射治疗通常用于治疗原发和转移性脑肿瘤，可引起 一些后遗症，包括进行性认知功能障碍。目前还没有可用的治疗方法 这甚至可以部分逆转辐射损伤后观察到的认知变化。具体地说，照射 颞叶可以深刻地影响调节学习和记忆的细胞结构。电离辐射 也一直被证明可以激活几个神经炎性信号级联反应，从而影响 多个神经过程和突触传递最终导致海马体功能中断。 值得注意的是，神经炎症过程中的关键细胞--常驻小胶质细胞和浸润性单核细胞， 有不同的胚胎学起源，也有不同的功能。激活的机制/S 炎症反应对脑照射后认知功能的影响及其具体作用不同 髓系细胞仍然难以捉摸。因此，显然有必要了解辐射损伤的机制和 炎症，以开发预防颅脑照射后认知功能下降的策略。 我们小组在上一次筹资期间的最新工作揭示了这些问题和 揭示了辐射诱发记忆背后的细胞和分子机制中的特定问题 赤字。具体地说，我们的数据显示了CCL2/CCR2与认知之间的直接联系。这些结果 提供外周先天免疫系统与脑照射后认知之间的机制联系。在……里面 在目前的提议中，我们将评估治疗剂量的颅脑照射诱导 外周血单核细胞的渗透，改变驻留的炎症反应并促进突触 功能障碍和长期认知缺陷。 目的1：确定辐射诱导的髓系细胞改变的动力学和炎症表型 在单次和次分割治疗剂量照射后。 目的2：评估外周血单核细胞重新募集到大脑中作为一种机械驱动因素的作用 辐射引起的突触和认知功能改变。 目的3：确定暂时去除髓系细胞是否能防止突触功能和认知能力的丧失 在单次和低分割剂量的放射治疗后。 在辐射诱导的病理生理学的演变方面，我们知之甚少。 外周来源的巨噬细胞聚集或炎症，以及这与突触和炎症改变的关系 认知功能。我们的最终治疗目标是改变辐射损伤后观察到的认知变化。

Project Summary Therapeutic irradiation is commonly used to treat both primary and metastatic brain tumors and can cause a number of late effects including progressive cognitive dysfunction. There is no treatment currently available that can even partially reverse cognitive changes observed after radiation injury. Specifically, irradiation of the temporal lobe can profoundly affect the cellular structures mediating learning and memory. Ionizing radiation has also been consistently shown to activate several neuroinflammatory signaling cascades that can impact multiple neural processes and synaptic transmission ultimately causing disruptions in hippocampal function. Notably, resident microglia and infiltrating monocytes, the key cellular player in neuroinflammatory processes, have distinct embryological origins and also fulfill different functions. The mechanism/s by which activation of the inflammatory response affect cognitive functions after brain irradiation and the specific role of different myeloid cells remain elusive. Thus, there is a clear need to understand the mechanisms of radiation injury and inflammation to develop strategies for preventing cognitive decline following cranial irradiation. Recent work from our group during the previous funding period has shed light in these questions and revealed specific problems in the cellular and molecular mechanisms underlying radiation-induced memory deficits. Specifically our data demonstrates a direct link between CCL2/CCR2 and cognition. These results provide a mechanistic link between peripheral innate immune system and cognition after brain irradiation. In the current proposal we will evaluate the central hypothesis that therapeutic doses of cranial irradiation induce infiltration of peripheral monocytes that modifies the resident inflammatory response and promotes synaptic dysfunction and long term cognitive deficits. Aim 1: Determine the kinetics and inflammatory phenotype of radiation-induced myeloid cell alterations after single and hypofractionated therapeutic doses of irradiation. Aim 2: Evaluate the role of peripheral monocyte recruitment into the brain as a mechanistic driver of radiation-induced altered synaptic and cognitive functions. Aim 3: Determine if temporary depletion of myeloid cells prevent the loss of synaptic function and cognition after single and hypofractionated doses of radiation. Very little is known in regard to the evolution of radiation induced pathophysiology in the context of peripherally derived macrophage accumulation or inflammation, and how this relates to altered synaptic and cognitive function. Our final therapeutic goal is to modify the cognitive changes observed after radiation injury.