Expression of the NLRP3 inflammasome in cerebral cortex after traumatic brain injury in a rat model

Neurochem Res. 2013 Oct;38(10):2072-83. doi: 10.1007/s11064-013-1115-z. Epub 2013 Jul 28.

Abstract

Inflammatory response plays an important role in the pathogenesis of secondary damage after traumatic brain injury (TBI). The inflammasome is a multiprotein complex involved in innate immunity and a number of studies have suggested that the inflammasome plays a critical role in a host inflammatory signaling. Nucleotide-binding domain, leucine-rich repeat, pyrin domain containing 3 (NLRP3) is a key component of the NLRP3-inflammasome, which also includes apoptotic speck-containing protein (ASC) with a cysteine protease (caspase)-activating recruitment domain and pro-caspase1. Activation of the NLRP3-inflammasome causes the processing and release of the interleukin 1 beta (IL-1β) and interleukin 18 (IL-18). Based on this, we hypothesized that the NLRP3-inflammasome could participate in the inflammatory response following TBI. However, the expression of NLRP3-inflammasome in cerebral cortex after TBI is not well known. Rats were randomly divided into control, sham and TBI groups (including 6 h, 1 day, 3 day and 7 day sub-group). TBI model was induced, and animals were sacrificed at each time point respectively. The expression of NLRP3-inflammasome was measured by quantitative real-time polymerase chain reaction, western blot and immunohistochemistry respectively. Immunofluorescent double labeling was performed to identify the cell types of NLRP3-inflammasome's expression. Moreover, enzyme linked immunosorbent assay was used to detect the alterations of IL-1β and IL-18 at each time point post-injury. The results showed that, TBI could induce assembly of NLRP3-inflammasome complex, increased expression of ASC, activation of caspase1, and processing of IL-1β and IL-18. These results suggested that NLRP3-inflammasome might play an important role in the inflammation induced by TBI and could be a target for TBI therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins
  • Brain Injuries / immunology
  • Brain Injuries / metabolism*
  • CARD Signaling Adaptor Proteins
  • Carrier Proteins
  • Caspase 1 / metabolism
  • Cerebral Cortex / metabolism*
  • Cytoskeletal Proteins / biosynthesis
  • Immunity, Innate
  • Inflammasomes / biosynthesis*
  • Inflammation / immunology
  • Inflammation / metabolism
  • Interleukin-18 / physiology
  • Interleukin-1beta / physiology
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cytoplasmic and Nuclear / biosynthesis*
  • Receptors, Cytoplasmic and Nuclear / physiology

Substances

  • Apoptosis Regulatory Proteins
  • CARD Signaling Adaptor Proteins
  • Carrier Proteins
  • Cytoskeletal Proteins
  • Inflammasomes
  • Interleukin-18
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, rat
  • Pycard protein, rat
  • Receptors, Cytoplasmic and Nuclear
  • Caspase 1