PDF(Pubmed)
Abstract：
Traumatic brain injury (TBI) is a significant public health concern characterized by a complex cascade of cellular events. TBI induces adenosine monophosphate-activated protein kinase (AMPK) dysfunction impairs energy balance activates inflammatory cytokines and leads to neuronal damage. AMPK is a key regulator of cellular energy homeostasis during inflammatory responses. Recent research has revealed its key role in modulating the inflammatory process in TBI. Following TBI the activation of AMPK can influence various important pathways and mechanisms including metabolic pathways and inflammatory signaling. Our study investigated the effects of post-TBI loss of AMPK function on functional outcomes inflammasome activation, and inflammatory cytokine production. Male C57BL/6 adult wild-type (WT) and AMPK knockout (AMPK-KO) mice were subjected to a controlled cortical impact (CCI) model of TBI or sham surgery. The mice were tested for behavioral impairment at 24 h post-TBI thereafter, mice were anesthetized, and their brains were quickly removed for histological and biochemical evaluation. In vitro we investigated inflammasome activation in mixed glial cells stimulated with lipopolysaccharides+ Interferon-gamma (LI) (0.1 μg/20 ng/ml LPS/IFNg) for 6 h to induce an inflammatory response. Estimating the nucleotide-binding domain, leucine-rich-containing family pyrin domain containing western blotting ELISA and qRT-PCR performed 3 (NLRP3) inflammasome activation and cytokine production. Our findings suggest that TBI leads to reduced AMPK phosphorylation in WT mice and that the loss of AMPK correlates with worsened behavioral deficits at 24 h post-TBI in AMPK-KO mice as compared to WT mice. Moreover compared with the WT mice AMPK-KO mice exhibit exacerbated NLRP3 inflammasome activation and increased expression of proinflammatory mediators such as IL-1b IL-6 TNF-a iNOS and Cox 2. These results align with the in vitro studies using brain glial cells under inflammatory conditions, demonstrating greater activation of inflammasome components in AMPK-KO mice than in WT mice. Our results highlighted the critical role of AMPK in TBI outcomes. We found that the absence of AMPK worsens behavioral deficits and heightens inflammasome-mediated inflammation thereby exacerbating brain injury after TBI. Restoring AMPK activity after TBI could be a promising therapeutic approach for alleviating TBI-related damage.
摘要：
创伤性脑损伤（TBI）是一个重要的公共卫生问题，其特征是细胞事件的复杂级联。TBI诱导一磷酸腺苷激活的蛋白激酶(AMPK)功能障碍损害能量平衡激活炎性细胞因子并导致神经元损伤。AMPK是炎症反应过程中细胞能量稳态的关键调节剂。最近的研究揭示了其在调节TBI炎症过程中的关键作用。在TBI之后,AMPK的活化可以影响各种重要的途径和机制,包括代谢途径和炎症信号传导。我们的研究调查了TBI后AMPK功能丧失对功能结局炎症小体激活的影响，和炎性细胞因子的产生。对雄性C57BL/6成年野生型(WT)和AMPK敲除(AMPK-KO)小鼠进行TBI或假手术的受控皮质冲击(CCI)模型。此后，在TBI后24小时测试小鼠的行为障碍，小鼠被麻醉，他们的大脑很快被切除以进行组织学和生化评估。在体外，我们研究了用脂多糖干扰素-γ（LI）（0.1µg/20ng/mlLPS/IFNg）刺激6小时以诱导炎症反应的混合神经胶质细胞中的炎性小体激活。估计核苷酸结合域，含富含亮氨酸的pyrin家族结构域的蛋白质印迹ELISA和qRT-PCR进行3（NLRP3）炎性体激活和细胞因子产生。我们的发现表明，与WT小鼠相比，TBI导致WT小鼠中AMPK磷酸化降低，并且AMPK-KO小鼠在TBI后24小时的丧失与行为缺陷恶化相关。此外，与WT小鼠相比，AMPK-KO小鼠表现出加剧的NLRP3炎性体激活和促炎介质如IL-1bIL-6TNF-aiNOS和Cox2的表达增加。这些结果与在炎症条件下使用脑胶质细胞的体外研究一致，证明AMPK-KO小鼠的炎性体成分激活比WT小鼠更大。我们的结果强调了AMPK在TBI结局中的关键作用。我们发现缺乏AMPK会使行为缺陷恶化，并加剧炎症小体介导的炎症，从而加剧TBI后的脑损伤。TBI后恢复AMPK活性可能是减轻TBI相关损伤的有希望的治疗方法。
