Zhang Yihua, Huang Ping, Cao Min, Chen Yi, Zhao Xinhu, He Xuzhi, Xu Lunshan
Department of Neurosurgery, Daping Hospital, Army Medical University, Chongqing, China.
Neural Regen Res. 2024 May;19(5):1072-1077. doi: 10.4103/1673-5374.382984.
MIcroglia/macrophage-mediated erythrophagocytosis plays a crucial role in hematoma clearance after intracerebral hemorrhage. Dynamic cytoskeletal changes accompany phagocytosis. However, whether and how these changes are associated with microglia/macrophage-mediated erythrophagocytosis remain unclear. In this study, we investigated the function of acetylated α-tubulin, a stabilized microtubule form, in microglia/macrophage erythrophagocytosis after intracerebral hemorrhage both in vitro and in vivo. We first assessed the function of acetylated α-tubulin in erythrophagocytosis using primary DiO GFP-labeled red blood cells co-cultured with the BV2 microglia or RAW264.7 macrophage cell lines. Acetylated α-tubulin expression was significantly decreased in BV2 and RAW264.7 cells during erythrophagocytosis. Moreover, silencing α-tubulin acetyltransferase 1 (ATAT1), a newly discovered α-tubulin acetyltransferase, decreased Ac-α-tub levels and enhanced the erythrophagocytosis by BV2 and RAW264.7 cells. Consistent with these findings, in ATAT1 mice, we observed increased ionized calcium binding adapter molecule 1 (Iba1) and Perls-positive microglia/macrophage phagocytes of red blood cells in peri-hematoma and reduced hematoma volume in mice with intracerebral hemorrhage. Additionally, knocking out ATAT1 alleviated neuronal apoptosis and pro-inflammatory cytokines and increased anti-inflammatory cytokines around the hematoma, ultimately improving neurological recovery of mice after intracerebral hemorrhage. These findings suggest that ATAT1 deficiency accelerates erythrophagocytosis by microglia/macrophages and hematoma absorption after intracerebral hemorrhage. These results provide novel insights into the mechanisms of hematoma clearance and suggest ATAT1 as a potential target for the treatment of intracerebral hemorrhage.
小胶质细胞/巨噬细胞介导的红细胞吞噬作用在脑出血后的血肿清除中起关键作用。吞噬作用伴随着动态的细胞骨架变化。然而，这些变化是否以及如何与小胶质细胞/巨噬细胞介导的红细胞吞噬作用相关仍不清楚。在本研究中，我们在体外和体内研究了稳定的微管形式——乙酰化α-微管蛋白在脑出血后小胶质细胞/巨噬细胞红细胞吞噬作用中的功能。我们首先使用与BV2小胶质细胞或RAW264.7巨噬细胞系共培养的原代DiO绿色荧光蛋白标记的红细胞评估乙酰化α-微管蛋白在红细胞吞噬作用中的功能。在红细胞吞噬过程中，BV2和RAW264.7细胞中的乙酰化α-微管蛋白表达显著降低。此外，沉默新发现的α-微管蛋白乙酰转移酶1（ATAT1）可降低乙酰化α-微管水平，并增强BV2和RAW264.7细胞的红细胞吞噬作用。与这些发现一致，在ATAT1基因敲除小鼠中，我们观察到脑出血小鼠血肿周围离子化钙结合衔接分子1（Iba1）和Perls阳性的小胶质细胞/巨噬细胞吞噬红细胞增加，血肿体积减小。此外，敲除ATAT1可减轻神经元凋亡和促炎细胞因子，并增加血肿周围的抗炎细胞因子，最终改善脑出血后小鼠的神经功能恢复。这些发现表明，ATAT1缺乏可加速脑出血后小胶质细胞/巨噬细胞的红细胞吞噬作用和血肿吸收。这些结果为血肿清除机制提供了新的见解，并表明ATAT1作为脑出血治疗的潜在靶点。
