Mycobacterium tuberculosis upregulates microglial matrix metalloproteinase-1 and -3 expression and secretion via NF-kappaB- and Activator Protein-1-dependent monocyte networks

J Immunol. 2010 Jun 1;184(11):6492-503. doi: 10.4049/jimmunol.0903811. Epub 2010 May 5.

Abstract

Inflammatory tissue destruction is central to pathology in CNS tuberculosis (TB). We hypothesized that microglial-derived matrix metalloproteinases (MMPs) have a key role in driving such damage. Analysis of all of the MMPs demonstrated that conditioned medium from Mycobacterium tuberculosis-infected human monocytes (CoMTb) stimulated greater MMP-1, -3, and -9 gene expression in human microglial cells than direct infection. In patients with CNS TB, MMP-1/-3 immunoreactivity was demonstrated in the center of brain granulomas. Concurrently, CoMTb decreased expression of the inhibitors, tissue inhibitor of metalloproteinase-2, -3, and -4. MMP-1/-3 secretion was significantly inhibited by dexamethasone, which reduces mortality in CNS TB. Surface-enhanced laser desorption ionization time-of-flight analysis of CoMTb showed that TNF-alpha and IL-1beta are necessary but not sufficient for upregulating MMP-1 secretion and act synergistically to drive MMP-3 secretion. Chemical inhibition and promoter-reporter analyses showed that NF-kappaB and AP-1 c-Jun/FosB heterodimers regulate CoMTb-induced MMP-1/-3 secretion. Furthermore, NF-kappaB p65 and AP-1 c-Jun subunits were upregulated in biopsy granulomas from patients with cerebral TB. In summary, functionally unopposed, network-dependent microglial MMP-1/-3 gene expression and secretion regulated by NF-kappaB and AP-1 subunits were demonstrated in vitro and, for the first time, in CNS TB patients. Dexamethasone suppression of MMP-1/-3 gene expression provides a novel mechanism explaining the benefit of steroid therapy in these patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Inflammatory Agents / pharmacology
  • Dexamethasone / pharmacology
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescent Antibody Technique
  • Gene Expression
  • Gene Expression Profiling
  • Humans
  • Matrix Metalloproteinase 1 / genetics
  • Matrix Metalloproteinase 1 / immunology
  • Matrix Metalloproteinase 1 / metabolism*
  • Matrix Metalloproteinase 3 / genetics
  • Matrix Metalloproteinase 3 / immunology
  • Matrix Metalloproteinase 3 / metabolism*
  • Microglia / immunology
  • Microglia / metabolism*
  • Microscopy, Confocal
  • Monocytes / immunology
  • Monocytes / metabolism
  • Mycobacterium tuberculosis / immunology
  • NF-kappa B / genetics
  • NF-kappa B / immunology
  • NF-kappa B / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / immunology
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Transcription Factor AP-1 / genetics
  • Transcription Factor AP-1 / immunology
  • Transcription Factor AP-1 / metabolism*
  • Tuberculosis, Central Nervous System / genetics
  • Tuberculosis, Central Nervous System / immunology
  • Tuberculosis, Central Nervous System / metabolism*
  • Up-Regulation

Substances

  • Anti-Inflammatory Agents
  • NF-kappa B
  • Transcription Factor AP-1
  • Dexamethasone
  • Matrix Metalloproteinase 3
  • Matrix Metalloproteinase 1