Astrocyte EV-Induced lincRNA-Cox2 Regulates Microglial Phagocytosis: Implications for Morphine-Mediated Neurodegeneration

Guoku Hu, Ke Liao, Fang Niu, Lu Yang, Blake W. Dallon, Shannon Callen, Changhai Tian, Jiang Shu, Juan Cui, Zhiqiang Sun, Yuri L. Lyubchenko, Minhan Ka, Xian-Ming Chen, Shilpa Buch

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Impairment of microglial functions, such as phagocytosis and/or dysregulation of immune responses, has been implicated as an underlying factor involved in the pathogenesis of various neurodegenerative disorders. Our previous studies have demonstrated that long intergenic noncoding RNA (lincRNA)-Cox2 expression is influenced by nuclear factor κB (NF-κB) signaling and serves as a coactivator of transcriptional factors to regulate the expression of a vast array of immune-related genes in microglia. Extracellular vesicles (EVs) have been recognized as primary facilitators of cell-to-cell communication and cellular regulation. Herein, we show that EVs derived from astrocytes exposed to morphine can be taken up by microglial endosomes, leading, in turn, to activation of Toll-like receptor 7 (TLR7) with a subsequent upregulation of lincRNA-Cox2 expression, ultimately resulting in impaired microglial phagocytosis. This was further validated in vivo, wherein inhibition of microglial phagocytic activity was also observed in brain slices isolated from morphine-administrated mice compared with control mice. Additionally, we also showed that intranasal delivery of EVs containing lincRNA-Cox2 siRNA (small interfering RNA) was able to restore microglial phagocytic activity in mice administered morphine. These findings have ramifications for the development of EV-loaded RNA-based therapeutics for the treatment of various disorders involving functional impairment of microglia.

Original languageEnglish (US)
Pages (from-to)450-463
Number of pages14
JournalMolecular Therapy - Nucleic Acids
Volume13
DOIs
Publication statusPublished - Dec 7 2018

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All Science Journal Classification (ASJC) codes

  • Molecular Medicine
  • Drug Discovery

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