Zhang Bohao, Ran Yunwei, Wu Siting, Zhang Fang, Huang Huachen, Zhu Changlian, Zhang Shusheng, Zhang Xiaoan
Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Center of Advanced Analysis & Gene Sequencing, Zhengzhou University, Zhengzhou, China.
Front Neurol. 2021 Feb 18;12:607370. doi: 10.3389/fneur.2021.607370. eCollection 2021.
Hypoxic-ischemic (HI) brain injury is a major cause of neonatal death or lifetime disability without widely accepted effective pharmacological treatments. It has been shown that the survival of microglia requires colony-stimulating factor 1 receptor (CSF1R) signaling and microglia participate in neonatal HI brain injury. We therefore hypothesize that microglia depletion during a HI insult period could reduce immature brain injury. In this study, CD1 mouse pups were treated with a CSF1R inhibitor (PLX3397, 25 mg/kg/daily) or a vehicle from postnatal day 4 to day 11 (P4-11), and over 90% of total brain microglia were deleted at P9. Unilateral hemisphere HI injury was induced at P9 by permanently ligating the left common carotid arteries and exposing the pups to 10% oxygen for 30 min to produce moderate left hemisphere injury. We found that the PLX3397 treatment reduced HI brain injury by 46.4%, as evaluated by the percentage of brain infarction at 48 h after HI. Furthermore, CSF1R inhibition suppressed the infiltration of neutrophils (69.7% reduction, = 0.038), macrophages (77.4% reduction, = 0.009), and T cells (72.9% reduction, = 0.008) to the brain, the production of cytokines and chemokines (such as CCL12, CCL6, CCL21, CCL22, CCL19, IL7, CD14, and WISP-1), and reduced neuronal apoptosis as indicated by active caspase-3 labeled cells at 48 h after HI (615.20 ± 156.84/mm vs. 1,205.00 ± 99.15/mm, = 0.013). Our results suggest that CSF1R inhibition suppresses neuroinflammation and neonatal brain injury after acute cerebral hypoxia-ischemia in neonatal mice.
缺氧缺血性（HI）脑损伤是新生儿死亡或终身残疾的主要原因，目前尚无广泛接受的有效药物治疗方法。研究表明，小胶质细胞的存活需要集落刺激因子1受体（CSF1R）信号传导，且小胶质细胞参与新生儿HI脑损伤。因此，我们推测在HI损伤期清除小胶质细胞可减轻未成熟脑损伤。在本研究中，从出生后第4天到第11天（P4 - 11），给CD1小鼠幼崽每日腹腔注射CSF1R抑制剂（PLX3397，25 mg/kg）或溶剂对照，在P9时，超过90%的全脑小胶质细胞被清除。在P9时，通过永久性结扎左侧颈总动脉并将幼崽暴露于10%氧气中30分钟，诱导单侧半球HI损伤，以产生中度左侧半球损伤。我们发现，通过HI后48小时脑梗死百分比评估，PLX3397治疗使HI脑损伤降低了46.4%。此外，抑制CSF1R可抑制中性粒细胞（减少69.7%，P = 0.038）、巨噬细胞（减少77.4%，P = 0.009）和T细胞（减少72.9%，P = 0.008）向脑内浸润，抑制细胞因子和趋化因子（如CCL12、CCL6、CCL21、CCL22、CCL19、IL7、CD14和WISP - 1）的产生，并减少HI后48小时活性半胱天冬酶 - 3标记细胞所指示的神经元凋亡（615.20 ± 156.84/mm对1,205.00 ± 99.15/mm，P = 0.013）。我们的结果表明，抑制CSF1R可抑制新生小鼠急性脑缺氧缺血后的神经炎症和新生儿脑损伤。
