PI3K/蛋白激酶B信号通路激活对反应性星形胶质细胞的影响:从有害作用到保护功能
Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions.
作者信息
Pérez-Núñez Ramón, González María Fernanda, Avalos Ana María, Leyton Lisette
机构信息
Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Center for Studies on Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile.
出版信息
Neural Regen Res. 2025 Apr 1;20(4):1031-1041. doi: 10.4103/NRR.NRR-D-23-01756. Epub 2024 Jun 3.
Astrocytes are the most abundant type of glial cell in the central nervous system. Upon injury and inflammation, astrocytes become reactive and undergo morphological and functional changes. Depending on their phenotypic classification as A1 or A2, reactive astrocytes contribute to both neurotoxic and neuroprotective responses, respectively. However, this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and injuries. Transcriptomic analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles, which emphasizes the heterogeneous nature of their reactivity. Astrocytes actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types, releasing cytokines, and influencing the immune response. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior, as evidenced by in silico , in vitro , and in vivo results. In astrocytes, inflammatory cues trigger a cascade of molecular events, where nuclear factor-κB serves as a central mediator of the pro-inflammatory responses. Here, we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their activation. We highlight the involvement of various signaling pathways that regulate astrocyte reactivity, including the PI3K/AKT/mammalian target of rapamycin (mTOR), α v β 3 integrin/PI3K/AKT/connexin 43, and Notch/PI3K/AKT pathways. While targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage, evidence suggests that activating this pathway could also yield beneficial outcomes. This dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function modulation. The review emphasizes the importance of employing astrocyte-exclusive models to understand their functions accurately and these models are essential for clarifying astrocyte behavior. The findings should then be validated using in vivo models to ensure real-life relevance. The review also highlights the significance of PI3K/AKT pathway modulation in preventing central nervous system damage, although further studies are required to fully comprehend its role due to varying factors such as different cell types, astrocyte responses to inflammation, and disease contexts. Specific strategies are clearly necessary to address these variables effectively.
星形胶质细胞是中枢神经系统中数量最多的胶质细胞类型。在损伤和炎症发生时,星形胶质细胞会发生反应并经历形态和功能变化。根据其表型分类为A1或A2,反应性星形胶质细胞分别对神经毒性和神经保护反应有贡献。然而,这种二元分类并不能完全涵盖在不同疾病和损伤中观察到的星形胶质细胞反应的多样性。转录组分析表明,反应性星形胶质细胞具有复杂的基因表达谱景观,这强调了其反应性的异质性。星形胶质细胞通过与小胶质细胞和其他细胞类型相互作用、释放细胞因子以及影响免疫反应,积极参与调节中枢神经系统炎症。磷酸肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路是星形胶质细胞反应性的核心参与者,并影响星形胶质细胞行为的各个方面,计算机模拟、体外和体内实验结果均证明了这一点。在星形胶质细胞中,炎症信号触发一系列分子事件,其中核因子κB作为促炎反应的核心介质。在这里,我们综述反应性星形胶质细胞的异质性及其激活的分子机制。我们强调了调节星形胶质细胞反应性的各种信号通路的参与,包括PI3K/AKT/雷帕霉素哺乳动物靶蛋白(mTOR)、αvβ3整合素/PI3K/AKT/连接蛋白43和Notch/PI3K/AKT通路。虽然靶向PI3K/AKT细胞信号通路的失活以控制反应性星形胶质细胞并预防中枢神经系统损伤,但有证据表明激活该通路也可能产生有益的结果。PI3K/AKT通路的这种双重功能强调了其在星形胶质细胞反应性和脑功能调节中的复杂性。该综述强调了采用星形胶质细胞特异性模型来准确理解其功能的重要性,这些模型对于阐明星形胶质细胞行为至关重要。然后应使用体内模型对研究结果进行验证,以确保与实际情况相关。该综述还强调了PI3K/AKT通路调节在预防中枢神经系统损伤中的重要性,尽管由于不同细胞类型、星形胶质细胞对炎症的反应以及疾病背景等多种因素,需要进一步研究以全面理解其作用。显然需要特定策略来有效应对这些变量。