Translocator protein is a marker of activated microglia in rodent models but not human neurodegenerative diseases

Microglial activation plays central roles in neuroinflammatory and neurodegenerative diseases. Positron emission tomography (PET) targeting 18 kDa Translocator Protein (TSPO) is widely used for localising inflammation in vivo, but its quantitative interpretation remains uncertain. We show that TSPO expression increases in activated microglia in mouse brain disease models but does not change in a non-human primate disease model or in common neurodegenerative and neuroinflammatory human diseases. We describe genetic divergence in the TSPO gene promoter, consistent with the hypothesis that the increase in TSPO expression in activated myeloid cells depends on the transcription factor AP1 and is unique to a subset…

• NS
  National Science Foundation
• IC
  Israel Cancer Research Fund
• RU
  Rush University
• AS
  Alzheimer's Society
• NI
  National Institute for Health and Care Research
• IC
  Imperial College London
• IC
  Imperial College Healthcare NHS Trust
• UO
  University of Oxford
• SN
  Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung

  Awards: 310030_212322, P2GEP3_191446, 320030_184713
• UD
  UK Dementia Research Institute
• NI
  National Institutes of Health

  Awards: U01AG061356, U01AG046152, RF1AG057473, R01AG066831, U01AG072572
• MR
  Medical Research Council

  Awards: MR/N008219/1, MR/N013255/1, MR/N008219/1, MR/T031891/1, MR/N026934/1