Inhibition of microglia activation as a phenotypic assay in early drug discovery.
Complex biological processes such as inflammation, cell death, migration, proliferation, and the release of biologically active molecules can be used as outcomes in phenotypic assays during early stages of drug discovery. Although target-based approaches have been widely used over the past decades, a disproportionate number of first-in-class drugs have been identified using phenotypic screening. This review details phenotypic assays based on inhibition of microglial activation and their utility in primary and secondary screening, target validation, and pathway elucidation. The role of microglia, both in normal as well as in pathological conditions such as chronic neurodegenerative diseases, is reviewed. Methodologies to assess microglia activation in vitro are discussed in detail, and classes of therapeutic drugs known to decrease the proinflammatory and cytotoxic responses of activated microglia are appraised, including inhibitors of glutaminase, cystine/glutamate antiporter, nuclear factor κB, and mitogen-activated protein kinases.
1Brain Science Institute NeuroTranslational Drug Discovery Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Mariana
M
Figuera-Losada
Camilo
C
Rojas
Barbara S
BS
Slusher
D000818:Animals; D055808:Drug Discovery / Q000379:methods*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism*; D019636:Neurodegenerative Diseases / Q000188:drug therapy / Q000378:metabolism; D010641:Phenotype
cell-based assays; cytokines; glutamate; nitric oxide; reactive oxygen species; screening