title: Screening for inhibitors of microglia to reduce neuroinflammation.
abstract: BACKGROUND
  Despite the significant role microglia play in the pathology of multiple sclerosis (MS), medications that act within the central nervous system (CNS) to inhibit microglia have not yet been identified as treatment options.
  
  
  OBJECTIVE
  We screened 1040 compounds with the aim of identifying inhibitors of microglia to reduce neuroinflammation.
  
  
  METHODS
  The NINDs collection of 1040 compounds, where most are therapeutic medications, was tested at 10 µM final concentration on lipopolysaccharide (LPS)-activated human microglia. An ELISA was run on the media to measure the level of TNF-α as an indicator of microglia activity. For compounds that reduce LPS-activated TNF-α levels by over 50%, considered as a potential inhibitor of interest, toxicity tests were conducted to exclude non-specific cytotoxicity. Promising compounds were subjected to further analyses, including toxicity to other CNS cell types, and multiplex assays.
  
  
  RESULTS
  Of 1040 compounds tested, 123 reduced TNF-α levels of LPS-activated microglia by over 50%. However, most of these were cytotoxic to microglia at the concentration tested while 54 were assessed to be non-toxic. Of the latter, spironolactone was selected for further analyses. Spironolactone reduced TNF-α levels of activated microglia by 50-60% at 10 µM, and this concentration did not kill microglia, neurons or astrocytes. In multiplex assays, spironolactone reduced several molecules in activated microglia. Finally, during the screening, we identified 9 compounds that elevated further the TNF-α levels in LPS-activated microglia.
  
  
  CONCLUSIONS
  Many of the non-toxic compounds identified in this screen as inhibitors of microglia, including spironolactone, may be explored as viable therapeutic options in MS.
authors.affiliation: University of Calgary, 3330 Hospital Drive, Calgary, Alberta T2N 4N1, Canada. vyong@ucalgary.ca.
authors.forename: Shazia
authors.initials: S
authors.lastname: Samanani
authors.forename: Manoj
authors.initials: M
authors.lastname: Mishra
authors.forename: Claudia
authors.initials: C
authors.lastname: Silva
authors.forename: Brooke
authors.initials: B
authors.lastname: Verhaeghe
authors.forename: Janet
authors.initials: J
authors.lastname: Wang
authors.forename: Jade
authors.initials: J
authors.lastname: Tong
authors.forename: V Wee
authors.initials: VW
authors.lastname: Yong
mesh_terms: D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005333:Fetus; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology* / Q000517:prevention & control*; D008070:Lipopolysaccharides / Q000633:toxicity; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D013148:Spironolactone / Q000494:pharmacology*
chemical_list: D008070:Lipopolysaccharides; D013148:Spironolactone