Socodato Renato, Portugal Camila C, Domith Ivan, Oliveira Nádia A, Coreixas Vivian S M, Loiola Erick C, Martins Tânia, Santiago Ana Raquel, Paes-de-Carvalho Roberto, Ambrósio António F, Relvas João B
Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal; Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Faculty of Medicine, Centre of Ophthalmology and Vision Sciences, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal.
Glia. 2015 Mar;63(3):497-511. doi: 10.1002/glia.22767. Epub 2014 Nov 24.
Microglial cells are the resident macrophages of the central nervous system. Their function is essential for neuronal tissue homeostasis. After inflammatory stimuli, microglial cells become activated changing from a resting and highly ramified cell shape to an amoeboid-like morphology. These morphological changes are associated with the release of proinflammatory cytokines and glutamate, as well as with high phagocytic activity. The acquisition of such phenotype has been associated with activation of cytoplasmic tyrosine kinases, including those of the Src family (SFKs). In this study, using both in vivo and in vitro inflammation models coupled to FRET-based time-lapse microscopy, lentiviruses-mediated shRNA delivery and genetic gain-of-function experiments, we demonstrate that among SFKs c-Src function is necessary and sufficient for triggering microglia proinflammatory signature, glutamate release, microglia-induced neuronal loss, and phagocytosis. c-Src inhibition in retinal neuroinflammation experimental paradigms consisting of intravitreal injection of LPS or ischemia-reperfusion injury significantly reduced microglia activation changing their morphology to a more resting phenotype and prevented neuronal apoptosis. Our data demonstrate an essential role for c-Src in microglial cell activation.
小胶质细胞是中枢神经系统中的常驻巨噬细胞。它们的功能对于神经元组织的稳态至关重要。在炎症刺激后，小胶质细胞被激活，从静止且高度分支的细胞形态转变为类阿米巴样形态。这些形态变化与促炎细胞因子和谷氨酸的释放以及高吞噬活性相关。这种表型的获得与细胞质酪氨酸激酶的激活有关，包括Src家族（SFKs）的激酶。在本研究中，我们使用体内和体外炎症模型，并结合基于荧光共振能量转移（FRET）的延时显微镜、慢病毒介导的短发夹RNA（shRNA）递送以及基因功能获得实验，证明在SFKs中，c-Src的功能对于触发小胶质细胞的促炎特征、谷氨酸释放、小胶质细胞诱导的神经元丢失和吞噬作用是必要且充分的。在由玻璃体内注射脂多糖（LPS）或缺血再灌注损伤组成的视网膜神经炎症实验范式中，抑制c-Src可显著降低小胶质细胞的激活，使其形态转变为更静止的表型，并防止神经元凋亡。我们的数据证明了c-Src在小胶质细胞激活中的重要作用。
