Modulating inflammatory monocytes with a unique microRNA gene signature ameliorates murine ALS

J Clin Invest. 2012 Sep;122(9):3063-87. doi: 10.1172/JCI62636. Epub 2012 Aug 6.


Amyotrophic lateral sclerosis (ALS) is a progressive disease associated with neuronal cell death that is thought to involve aberrant immune responses. Here we investigated the role of innate immunity in a mouse model of ALS. We found that inflammatory monocytes were activated and that their progressive recruitment to the spinal cord, but not brain, correlated with neuronal loss. We also found a decrease in resident microglia in the spinal cord with disease progression. Prior to disease onset, splenic Ly6Chi monocytes expressed a polarized macrophage phenotype (M1 signature), which included increased levels of chemokine receptor CCR2. As disease onset neared, microglia expressed increased CCL2 and other chemotaxis-associated molecules, which led to the recruitment of monocytes to the CNS by spinal cord-derived microglia. Treatment with anti-Ly6C mAb modulated the Ly6Chi monocyte cytokine profile, reduced monocyte recruitment to the spinal cord, diminished neuronal loss, and extended survival. In humans with ALS, the analogous monocytes (CD14+CD16-) exhibited an ALS-specific microRNA inflammatory signature similar to that observed in the ALS mouse model, linking the animal model and the human disease. Thus, the profile of monocytes in ALS patients may serve as a biomarker for disease stage or progression. Our results suggest that recruitment of inflammatory monocytes plays an important role in disease progression and that modulation of these cells is a potential therapeutic approach.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyotrophic Lateral Sclerosis / drug therapy
  • Amyotrophic Lateral Sclerosis / genetics
  • Amyotrophic Lateral Sclerosis / immunology*
  • Amyotrophic Lateral Sclerosis / pathology
  • Animals
  • Antibodies, Monoclonal / administration & dosage
  • Antigens, CD / genetics
  • Antigens, CD / metabolism
  • Antigens, Ly / genetics
  • Antigens, Ly / immunology
  • Antigens, Ly / metabolism
  • Apoptosis
  • Apyrase / genetics
  • Apyrase / metabolism
  • Cell Proliferation
  • Chemotaxis
  • Female
  • Gene Regulatory Networks
  • Humans
  • Immunomodulation*
  • Inflammation Mediators / metabolism
  • Macrophages, Alveolar / metabolism
  • Male
  • Metabolic Networks and Pathways
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Microglia / immunology
  • Microglia / pathology
  • Monocytes / immunology*
  • Monocytes / metabolism
  • Monocytes / pathology
  • Oligonucleotide Array Sequence Analysis
  • RNA Interference
  • Rats
  • Rats, Inbred Lew
  • Spinal Cord / immunology*
  • Spinal Cord / pathology
  • Spleen / immunology
  • Spleen / pathology
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase-1
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcriptome


  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, Ly
  • Inflammation Mediators
  • Ly-6C antigen, mouse
  • MicroRNAs
  • SOD1 protein, human
  • Transcription Factors
  • Sod1 protein, mouse
  • Sod1 protein, rat
  • Superoxide Dismutase
  • Superoxide Dismutase-1
  • Apyrase
  • CD39 antigen