Microglial Inflammasome Activation in Penetrating Ballistic-Like Brain Injury

Stephanie W. Lee, Shyam Gajavelli, Markus S. Spurlock, Cody Andreoni, Juan Pablo P de Rivero Vaccari, Ross Bullock, Robert Keane, W. Dalton Dietrich

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Penetrating traumatic brain injury (PTBI) is a significant cause of death and disability in the United States. Inflammasomes are one of the key regulators of the interleukin (IL)-1β mediated inflammatory responses after traumatic brain injury. However, the contribution of inflammasome signaling after PTBI has not been determined. In this study, adult male Sprague-Dawley rats were subjected to sham procedures or penetrating ballistic-like brain injury (PBBI) and sacrificed at various time-points. Tissues were assessed by immunoblot analysis for expression of IL-1β, IL-18, and components of the inflammasome: apoptosis-associated speck-like protein containing a caspase-activation and recruitment domain (ASC), caspase-1, X-linked inhibitor of apoptosis protein (XIAP), nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3), and gasdermin-D (GSDMD). Specific cell types expressing inflammasome proteins also were evaluated immunohistochemically and assessed quantitatively. After PBBI, expression of IL-1β, IL-18, caspase-1, ASC, XIAP, and NLRP3 peaked around 48 h. Brain protein lysates from PTBI animals showed pyroptosome formation evidenced by ASC laddering, and also contained increased expression of GSDMD at 48 h after injury. ASC-positive immunoreactive neurons within the perilesional cortex were observed at 24 h. At 48 h, ASC expression was concentrated in morphologically activated cortical microglia. This expression of ASC in activated microglia persisted until 12 weeks following PBBI. This is the first report of inflammasome activation after PBBI. Our results demonstrate cell-specific patterns of inflammasome activation and pyroptosis predominantly in microglia, suggesting a sustained pro-inflammatory state following PBBI, thus offering a therapeutic target for this type of brain injury.

Original languageEnglish (US)
Pages (from-to)1681-1693
Number of pages13
JournalJournal of Neurotrauma
Volume35
Issue number14
DOIs
StatePublished - Jul 15 2018

Fingerprint

Inflammasomes
Brain Injuries
Penetrating Head Injuries
Microglia
X-Linked Inhibitor of Apoptosis Protein
Interleukin-1
Caspase 1
Interleukin-18
Proteins
Protein Binding
Sprague Dawley Rats
Cause of Death
Nucleotides
Apoptosis
Neurons
Traumatic Brain Injury
Wounds and Injuries
Brain

Keywords

  • inflammasome; microglia; penetrating ballistic-like brain injury; penetrating traumatic brain injury

ASJC Scopus subject areas

  • Clinical Neurology

Cite this

Microglial Inflammasome Activation in Penetrating Ballistic-Like Brain Injury. / Lee, Stephanie W.; Gajavelli, Shyam; Spurlock, Markus S.; Andreoni, Cody; de Rivero Vaccari, Juan Pablo P; Bullock, Ross; Keane, Robert; Dalton Dietrich, W.

In: Journal of Neurotrauma, Vol. 35, No. 14, 15.07.2018, p. 1681-1693.

Research output: Contribution to journalArticle

Lee, Stephanie W. ; Gajavelli, Shyam ; Spurlock, Markus S. ; Andreoni, Cody ; de Rivero Vaccari, Juan Pablo P ; Bullock, Ross ; Keane, Robert ; Dalton Dietrich, W. / Microglial Inflammasome Activation in Penetrating Ballistic-Like Brain Injury. In: Journal of Neurotrauma. 2018 ; Vol. 35, No. 14. pp. 1681-1693.
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