Increased growth factor expression and cell proliferation after contusive spinal cord injury

Area of Science:

• Neuroscience
• Regenerative Medicine
• Cell Biology

Background:

• Traumatic central nervous system (CNS) injury involves primary and secondary phases of cell death.
• Spinal cord injury (SCI) leads to significant loss of astrocytes and oligodendrocytes, followed by repopulation.
• Endogenous growth factors are known to stimulate progenitor cell proliferation after CNS injury.

Purpose of the Study:

• To investigate the spatial correlation between growth factor up-regulation and cell proliferation after SCI.
• To determine the role of specific growth factors, glial growth factor (GGF2) and basic fibroblast growth factor (FGF2), in stimulating progenitor cell division post-injury.

Main Methods:

• Comparison of 5-bromodeoxyuridine (BrdU) incorporation (cell proliferation marker) with growth factor levels (FGF2, CNTF, GGF2) at different distances from the SCI epicenter.
• Immunohistochemistry and in situ hybridization were used to detect BrdU, FGF2, CNTF, and GGF2.
• In vitro experiments involving the addition of recombinant human GGF2 (rhGGF2) to cultured spinal cord cells.

Main Results:

• All three growth factors (FGF2, CNTF, GGF2) were significantly up-regulated 3 days after SCI, coinciding with maximal cell proliferation.
• GGF2 and FGF2 levels showed the highest increase 2 mm rostral to the epicenter, mirroring BrdU incorporation patterns.
• rhGGF2 treatment increased the number of NG2+ glial progenitors in cultured cells from injured spinal cords.

Conclusions:

• FGF2 and GGF2 are significantly up-regulated after SCI and correlate spatially with cell proliferation.
• These growth factors likely contribute to the spontaneous recovery after SCI by promoting the proliferation of endogenous progenitors.
• The findings suggest a therapeutic potential for FGF2 and GGF2 in spinal cord injury repair.