Matrix metalloproteinase-9 controls proliferation of NG2+ progenitor cells immediately after spinal cord injury

NG2+ cells are glial progenitor cells in the CNS that can become oligodendrocytes, which are important for remyelination after spinal cord injury. This study investigates the role of matrix metalloproteinases (MMPs), particularly MMP-9, in regulating the proliferation of NG2+ cells after spinal cord injury. The researchers found that inhibiting MMP-9 immediately after spinal cord injury increased the division of NG2+ cells, but not other types of glial cells like astrocytes or microglia. This suggests that MMP-9 normally suppresses NG2+ cell proliferation. Blocking MMP-9 also reduced the shedding of certain molecules from the surface of NG2+ cells, which is believed to promote their maturation into oligodendrocytes. This ultimately led to improved myelin repair and functional recovery after spinal cord injury.

• 1
  Acute inhibition of MMP-9/2 after spinal cord injury increases the proliferation of NG2+ progenitor cells but not astrocytes or microglia.
• 2
  MMP-9/2 inhibition reduces the shedding of NG2 proteoglycan and the NR1 subunit of the NMDA receptor.
• 3
  Acute MMP-9/2 blockade promotes post-mitotic maturation of oligodendrocytes, improves myelin neuropathology, and facilitates functional recovery.