Taylor Roslyn A, Chang Che-Feng, Goods Brittany A, Hammond Matthew D, Mac Grory Brian, Ai Youxi, Steinschneider Arthur F, Renfroe Stephen C, Askenase Michael H, McCullough Louise D, Kasner Scott E, Mullen Michael T, Hafler David A, Love J Christopher, Sansing Lauren H
J Clin Invest. 2017 Jan 3;127(1):280-292. doi: 10.1172/JCI88647. Epub 2016 Nov 28.
Intracerebral hemorrhage (ICH) is a devastating form of stroke that results from the rupture of a blood vessel in the brain, leading to a mass of blood within the brain parenchyma. The injury causes a rapid inflammatory reaction that includes activation of the tissue-resident microglia and recruitment of blood-derived macrophages and other leukocytes. In this work, we investigated the specific responses of microglia following ICH with the aim of identifying pathways that may aid in recovery after brain injury. We used longitudinal transcriptional profiling of microglia in a murine model to determine the phenotype of microglia during the acute and resolution phases of ICH in vivo and found increases in TGF-β1 pathway activation during the resolution phase. We then confirmed that TGF-β1 treatment modulated inflammatory profiles of microglia in vitro. Moreover, TGF-β1 treatment following ICH decreased microglial Il6 gene expression in vivo and improved functional outcomes in the murine model. Finally, we observed that patients with early increases in plasma TGF-β1 concentrations had better outcomes 90 days after ICH, confirming the role of TGF-β1 in functional recovery from ICH. Taken together, our data show that TGF-β1 modulates microglia-mediated neuroinflammation after ICH and promotes functional recovery, suggesting that TGF-β1 may be a therapeutic target for acute brain injury.
脑出血(ICH)是一种严重的中风形式,由脑血管破裂引起,导致脑实质内出现血肿。这种损伤会引发快速的炎症反应,包括组织驻留小胶质细胞的激活以及血液来源的巨噬细胞和其他白细胞的募集。在这项研究中,我们调查了脑出血后小胶质细胞的特异性反应,旨在确定可能有助于脑损伤后恢复的途径。我们在小鼠模型中对小胶质细胞进行纵向转录谱分析,以确定体内脑出血急性期和消退期小胶质细胞的表型,发现消退期转化生长因子-β1(TGF-β1)信号通路激活增加。然后我们证实,TGF-β1处理在体外可调节小胶质细胞的炎症谱。此外,脑出血后给予TGF-β1处理可降低体内小胶质细胞白细胞介素-6(Il6)基因表达,并改善小鼠模型的功能结局。最后,我们观察到血浆TGF-β1浓度早期升高的脑出血患者在发病90天后预后更好,证实了TGF-β1在脑出血功能恢复中的作用。综上所述,我们的数据表明,TGF-β1可调节脑出血后小胶质细胞介导的神经炎症并促进功能恢复,提示TGF-β1可能是急性脑损伤的治疗靶点。