Long- and short-term intravital imaging reveals differential spatiotemporal recruitment and function of myelomonocytic cells after spinal cord injury

J Physiol. 2013 Oct 1;591(19):4895-902. doi: 10.1113/jphysiol.2013.256388. Epub 2013 Aug 5.

Abstract

After spinal cord injury (SCI), resident and peripheral myelomonocytic cells are recruited to the injury site and play a role in injury progression. These cells are important for clearing cellular debris, and can modulate the retraction and growth of axons in vitro. However, their precise spatiotemporal recruitment dynamics is unknown, and their respective roles after SCI remain heavily debated. Using chronic, quantitative intravital two-photon microscopy of adult mice with SCI, here we show that infiltrating lysozyme M (LysM(+)) and resident CD11c(+) myelomonocytic cells have distinct spatiotemporal recruitment profiles, and exhibit changes in morphology, motility, phagocytic activity and axon interaction patterns over time. This study provides the first in vivo description of the influx of inflammatory and resident myelomonocytic cells into the injured spinal cord and their interactions with cut axons, and underscores the importance of precise timing and targeting of specific cell populations in developing therapies for SCI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / pathology
  • CD11c Antigen / genetics
  • CD11c Antigen / metabolism
  • Cell Movement*
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Fluorescence, Multiphoton
  • Monocytes / metabolism
  • Monocytes / pathology
  • Monocytes / physiology*
  • Muramidase / genetics
  • Muramidase / metabolism
  • Optical Imaging
  • Phagocytosis
  • Spinal Cord Injuries / pathology*
  • Spinal Cord Injuries / physiopathology

Substances

  • CD11c Antigen
  • Muramidase
  • lysozyme M, mouse