Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province 215006, China; Department of Neurosurgery, The Fourth Affiliated Hospital of Soochow University (Suzhou Dushu Lake Hospital), Suzhou, Jiangsu Province, 215000, China.
Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province 215006, China; Department of Neurosurgery, The 928th Hospital of People's Liberation Army Joint Logistic Support Force, Haikou, Hainan Province, 570000, China.
Exp Neurol. 2025 Jan;383:115019. doi: 10.1016/j.expneurol.2024.115019. Epub 2024 Oct 18.
Traumatic Brain Injury (TBI) is a multifaceted injury that can cause a wide range of symptoms and impairments, leading to significant effects on brain function. Nucleophosmin 1 (NPM1), a versatile phosphoprotein located in the nucleolus, is being recognized as a possible controller of cellular stress reactions and could be important in reducing neuro dysfunction caused by TBI. However the critical roles of NPM1 in cellular stress in TBI remains unclear.
We employed a control cortical impact mouse model and a scratch-induced primary neuronal culture model. Hematoxylin and eosin staining was used to evaluate tissue damage and cellular changes, with NPM1 expression in the cortical area assessed through immunofluorescence staining and Western blot analysis. Neuronal morphology was assessed using Nissl staining. Behavioral assessments were performed to evaluate the impact of NPM1 overexpression on neurobehavioral results in TBI mice. Mitochondrial function was assessed using an Extracellular Flux Analyzer.
Following TBI, an increase in NPM1 expression was observed, with a peak at 72 h post-injury. Increased levels of NPM1 resulted in decreased neuronal cell death, as shown by Nissl staining, and lower levels of Caspase 8, APE1, H2AX, and 8-OHDG expression, indicating a reduction in DNA damage. NPM1 overexpression also resulted in improved neurobehavioral outcomes, characterized by decreased neurological deficits and enhanced motor function post-TBI. Additionally, in vitro, scratch-induction experiments revealed that NPM1 overexpression mitigated mitochondrial damage, as evidenced by the downregulation of P53, BCL2, and Cyto C expression levels and improvements in mitochondrial respiratory function.
These findings suggest NPM1 as a promising target for developing interventions to alleviate TBI-related cellular stress and promote neuronal survival.
创伤性脑损伤（TBI）是一种多方面的损伤，可导致广泛的症状和损伤，对大脑功能产生重大影响。核仁磷酸蛋白 1（NPM1）是一种位于核仁中的多功能磷酸蛋白，它被认为是细胞应激反应的可能控制器，在减轻 TBI 引起的神经功能障碍方面可能很重要。然而，NPM1 在 TBI 中的细胞应激中的关键作用尚不清楚。
我们采用了对照皮质冲击小鼠模型和划痕诱导的原代神经元培养模型。苏木精和伊红染色用于评估组织损伤和细胞变化，通过免疫荧光染色和 Western blot 分析评估皮质区域的 NPM1 表达。使用尼氏染色评估神经元形态。行为评估用于评估 NPM1 过表达对 TBI 小鼠神经行为结果的影响。使用细胞外通量分析仪评估线粒体功能。
TBI 后，观察到 NPM1 表达增加，伤后 72 小时达到峰值。NPM1 水平的升高导致神经元细胞死亡减少，如尼氏染色所示，并且 Caspase 8、APE1、H2AX 和 8-OHDG 的表达水平降低，表明 DNA 损伤减少。NPM1 过表达还导致神经行为结果改善，表现为 TBI 后神经缺陷减少和运动功能增强。此外，在体外划痕诱导实验中，NPM1 过表达减轻了线粒体损伤，表现为 P53、BCL2 和 Cyto C 表达水平下调以及线粒体呼吸功能改善。
这些发现表明 NPM1 是一种有前途的靶点，可用于开发干预措施以减轻 TBI 相关的细胞应激并促进神经元存活。
