Stroke target identification guided by astrocyte transcriptome analysis

Rakers C,Schleif M,Blank N,Matušková H,2,Ulas T,Händler K,Torres SV,Schumacher T,Tai K,Schultze JL,,Jackson WS,Petzold GC,2

1.German Center for Neurodegenerative Diseases(DZNE),Bonn,Germany

2.Department of Neurology,University Hospital Bonn,Bonn,Germany

3.Genomics and Immunoregulation,LIMES-Institute,University of Bonn,Bonn,Germany

Abstract Astrocytes support normal brain function,but may also contribute to neurodegeneration when they become reactive under pathological conditions such as stroke.However,the molecular underpinnings of this context-dependent interplay between beneficial and detrimental properties in reactive astrogliosis have remained incompletely understood.Therefore,using the RiboTag technique,we immunopurified translating mRNAs specifically from astrocytes 72 hr after transient middle cerebral artery occlusion in mice(tMCAO),thereby generating a stroke-specific astroglial translatome database.We found that compared to control brains,reactive astrocytes after tMCAO show an enrichment of transcripts linked to the A2 phenotype,which has been associated with neuroprotection.However,we found that astrocytes also upregulate a large number of potentially neurotoxic genes.In total,we identified the differential expression of 1,003 genes and 38 transcription factors,of which Stat3,Sp1,and Spi1 were the most prominent.To further explore the effects of Stat3-mediated pathways on stroke pathogenesis,we subjected mice with an astrocyte-specific conditional deletion of Stat3 to tMCAO,and found that these mice have reduced stroke volume and improved motor outcome 72 hr after focal ischemia.Taken together,our study extends the emerging database of novel astrocyte-specific targets for stroke therapy,and supports the role of astrocytes as critical safeguards of brain function in health and disease.

Key words astroglia;ischemia;next generation sequencing

通过星形胶质细胞转录组分析寻找脑卒中治疗靶标

摘要星形胶质细胞支持正常的脑功能，但当它们在卒中等病理条件下变得具有反应性时也可能促成神经退行性病变。然而，反应性星形胶质细胞增生的有益和有害特性之间依赖于背景的相互作用的分子基础仍然未被完全理解。我们使用RiboTag技术，在短暂性大脑中动脉闭塞（tMCAO）72 h后的小鼠星形胶质细胞中特异性地纯化翻译mRNA，从而产生卒中特异性星形胶质细胞翻译组数据库。与对照组大脑相比，tMCAO后的反应性星形胶质细胞显示与A2表型相关的转录物富集，这与神经保护相关。我们还发现，星形胶质细胞也会上调大量潜在的神经毒性基因。本研究共鉴定了1,003个基因和38个转录因子的差异表达，其中Stat3，Sp1和Spi1是最显著的。为了进一步探索Stat3介导的途径对卒中发病机制的影响，我们对星形胶质细胞特异性条件性缺失Stat3的小鼠进行tMCAO处理，发现局灶性缺血72 h后的小鼠脑梗死体积减小，运动功能改善。综上所述，本研究扩展了新兴的星形胶质细胞特异性靶向卒中治疗数据库，支持星形胶质细胞在生理和病理条件下均对脑功能提供了关键保障作用的观点。

关键词星形胶质细胞；缺血；下一代测序

中图分类号R741；R741.02文献标识码ADOI10.16780/j.cnki.sjssgncj.2019.02.017