Spata2 Knockdown Exacerbates Brain Inflammation via NF-κB/P38MAPK Signaling and NLRP3 Inflammasome Activation in Cerebral Ischemia/Reperfusion Rats

Neurochem Res. 2021 Sep;46(9):2262-2275. doi: 10.1007/s11064-021-03360-8. Epub 2021 Jun 1.

Abstract

Brain inflammation induced by ischemic stroke is an important cause of secondary brain injury. The nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and NLRP3 inflammasome signaling are believed to drive the progression of brain inflammation. Spermatogenesis-associated protein2 (SPATA2) functions as a partner protein that recruits CYLD, a negative regulator of NF-κB signaling, to signaling complexes. However, the role of SPATA2 in the central nervous system remains unclear and whether it is involved in regulating inflammatory responses remains controversial. Rats were subjected to transient middle cerebral artery occlusion followed by reperfusion (tMCAO/R) surgery. The expression and localization of SPATA2 in the brain were investigated. The lentivirus-mediated shRNA was employed to inhibit SPATA2 expression. The inflammatory responses and outcomes of Spata2 knockdown were investigated. SPATA2 was co-localized with CYLD in neurons. SPATA2 expression was reduced in tMCAO/R rats. Spata2 knockdown resulted in increased microglia, increased expression of Tnfa, Il-1β, and Il-18, decreased Garcia score, and increased infarct volume. Spata2 knockdown resulted in the activation of P38MAPK and NLRP3 inflammasome and the increased activation of NF-κB signaling. These results suggest that SPATA2 plays a protective role against brain inflammation induced by ischemia/reperfusion injury. Therefore, SPATA2 could be a potential therapeutic target for treating ischemic stroke.

Keywords: CYLD; Cerebral ischemia/reperfusion; NF-κb; NLRP3 inflammasome; P38MAPK; Spermatogenesis-associated protein2.

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Brain / metabolism
  • Brain / pathology
  • Gene Knockdown Techniques
  • Infarction, Middle Cerebral Artery / metabolism*
  • Infarction, Middle Cerebral Artery / pathology
  • Inflammation / metabolism
  • Inflammation / pathology
  • MAP Kinase Signaling System / physiology*
  • Male
  • Microglia / metabolism
  • NF-kappa B / metabolism
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • NF-kappa B
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, rat
  • Spata2 protein, rat
  • p38 Mitogen-Activated Protein Kinases