Evidence for a detrimental role of TLR8 in ischemic stroke

Sung-Chun Tang, Shin-Joe Yeh, Yu-l Li, Yu-Chi Wang Wang, Sang-Ha Baik, Tomislav Santro, Alexander Widiapradja, Silvia Manzanero, Christopher Graeme Sobey, Dong-Gyu Jo, Thiruma Arumugam, Jiann-Shing Jeng

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

Toll-like receptors (TLRs) are transmembrane pattern-recognition receptors that initiate signals in response to diverse pathogen-associated molecular patterns. Several groups have recently reported a role for TLR2 and TLR4 in ischemic stroke-induced brain injury. However, relatively little is known about the role of TLR8 in ischemic stroke. Here we provide the first evidence that TLR8 activation plays a detrimental role in stroke outcome by promoting neuronal apoptosis and T cell-mediated post-stroke inflammation. TLR8 is expressed in cerebral cortical neurons, where its levels and downstream signaling via JNK are increased in response to oxygen glucose deprivation (OGD). Treatment with a TLR8 agonist activated pro-apoptotic JNK and increased neuronal cell death during OGD. Furthermore, selective knockdown of TLR8 using siRNA protected SH-SY5Y cells following OGD, and TLR8 agonist administration in vivo increased mortality, neurological deficit and T cell infiltration following stroke. Taken together, our findings indicate a detrimental role for neuronal TLR8 signaling in the triggering of post-stroke inflammation and neuronal death.
Original languageEnglish
Pages (from-to)341 - 347
Number of pages7
JournalExperimental Neurology
Volume250
DOIs
Publication statusPublished - 2013

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