FGF/Heparin Differentially Regulates Schwann Cell and Olfactory Ensheathing Cell Interactions with Astrocytes: A Role in Astrocytosis

After spinal cord injury, astrocytes react by proliferating and forming boundaries, increasing GFAP and CSPG expression. This study investigates how Schwann cells (SCs) and olfactory ensheathing cells (OECs) interact with astrocytes. Astrocytes mingle with OECs but not SCs in vivo. SC-conditioned media induces astrocyte proliferation and CSPG expression. In OEC/astrocyte cultures, SCM induces reactive astrocytosis and boundary formation, sensitive to FGFR1 inhibition but not FGF2 alone. Heparin induces boundary formation in OEC/astrocyte cultures, while heparinase reduces it in SC/astrocyte cultures. FGF2 and FGFR1 immunoreactivity increases over grafted OECs and SCs, with HSPG over reactive astrocytes bordering the SC graft.

• 1
  Schwann cell-conditioned media induces reactive astrocytosis and boundary formation in OEC/astrocyte cocultures, sensitive to FGFR1 inhibition.
• 2
  Heparin modulates astrocyte stress response; it induces boundary formation in OEC/astrocyte cultures, while heparinase reduces it in SC/astrocyte cultures.
• 3
  In vivo, FGF2 and FGFR1 immunoreactivity is increased over grafted OECs and Schwann cells, with HSPG increased over reactive astrocytes bordering Schwann cell grafts.