title: A novel cell line from spontaneously immortalized murine microglia.
abstract: BACKGROUND
  Purified microglia cultures are useful tools to study microglial behavior in vitro. Microglial cell lines serve as an attractive alternative to primary microglia culture, circumventing the costly and lengthy preparation of the latter. However, immortalization by genetic or pharmacologic manipulations may show altered physiology from primary microglia.
  
  
  METHODS
  A novel microglial cell line was isolated from a primary glial culture of postnatal murine cerebral cortices. The culture contained a population of spontaneously transformed microglia that continued to divide without genetic or pharmacological manipulations. After several clones were isolated, one particular clone, SIM-A9, was analyzed for its microglial characteristics.
  
  
  RESULTS
  SIM-A9 cells expressed macrophage/microglia-specific proteins, CD68 and Iba1. SIM-A9 cells were responsive to exogenous inflammatory stimulation with lipopolysaccharide and β-amyloid, triggering tyrosine kinase-based and NFκB signaling cascades as well as TNFα secretion. SIM-A9 cells also exhibited phagocytic uptake of fluorescent labeled β-amyloid and bacterial bioparticles. Furthermore, lipopolysaccharide increased the levels of inducible nitric oxide synthase and cyclooxygenase-2, whereas IL-4 stimulation increased arginase-1 levels demonstrating that SIM-A9 cells are capable of switching their profiles to pro- or anti-inflammatory phenotypes, respectively.
  
  
  METHODS
  The use of SIM-A9 cells avoids expensive and lengthy procedures required for the preparation of primary microglia. Spontaneously immortalized SIM-A9 cells are expected to behave more comparably to primary microglia than virally transformed or pharmacologically induced microglial cell lines.
  
  
  CONCLUSIONS
  SIM-A9 cells exhibit key characteristics of cultured primary microglia and may serve as a valuable model system for the investigation of microglial behavior in vitro.
authors: Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, 501 North Columbia Road, Stop 9037, Grand Forks, ND 58202-9037, USA. Electronic address: kumi.combs@med.und.edu.
authors: Kumi
authors: K
authors: Nagamoto-Combs
authors: Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, 504 Hamline Street, Neuroscience Building, Grand Forks, ND 58202, USA. Electronic address: joshua.kulas@my.und.edu.
authors: Joshua
authors: J
authors: Kulas
authors: Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, 504 Hamline Street, Neuroscience Building, Grand Forks, ND 58202, USA. Electronic address: colin.combs@med.und.edu.
authors: Colin K
authors: CK
authors: Combs
mesh_terms: D016229:Amyloid beta-Peptides / Q000633:toxicity; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001119:Arginase / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000378:metabolism; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010446:Peptide Fragments / Q000633:toxicity; D010587:Phagocytosis / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000097382:CD68 Molecule
chemical_list: D016229:Amyloid beta-Peptides; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D001119:Arginase; D002135:Calcium-Binding Proteins; D051546:Cyclooxygenase 2; D029968:Escherichia coli Proteins; D015847:Interleukin-4; D008070:Lipopolysaccharides; D008840:Microfilament Proteins; D016328:NF-kappa B; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D010446:Peptide Fragments; D011505:Protein-Tyrosine Kinases; D014409:Tumor Necrosis Factor-alpha; C491049:Aif1 protein, mouse; C081026:CD68 protein, mouse; D000097382:CD68 Molecule; C075222:amyloid beta-protein (1-42); C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; C544448:Arg1 protein, mouse
keywords: Beta-amyloid; Inflammation; Lipopolysaccharide; M1/M2 phenotype; Microglia; Phagocytosis