Figure 6. Flavopiridol decreases astrocytic reactivity after SCI. (A−B) western blot analysis showed that flavopiridol treatment significantly reduced the SCI-induced upregulation of GFAP at 4 weeks post-injury. Representative immunoblots are shown in panel A. (C−E) Increases of NG2 and CHL1 expression at 4 weeks after SCI were significantly attenuated by treatment of flavopiridol. Representative immunoblots are shown in panel C. *p <0.05 vs. vehicle group. n = 4–5 in vehicle or flavopiridol groups, n = 2 in sham or sham + flavopiridol group. (F) Wide-field high-resolution confocal images of a complete transversal section of the injured spinal cord (d-f) revealed that NG2 (green) and GFAP (red) immunoreactivity is increased throughout the cord at 4 weeks after SCI. This was attenuated by treatment with flavopiridol (g-i). Scale bars = 500 μm, (G) NG2-immunostained cells present in the border zone were double immunostained for GFAP (arrows). Note that immunostainings for GFAP also detected NG2-negative cells (arrowheads). NG2⁺-oligodendrocyte precursor cells cells were negative for GFAP (stars). (H) NG2⁺/p75⁺ Schwann cells were observed inside the lesion (arrows). (I) A subset of OX42⁺ macrophages in the central lesion area were transiently immunopositive for NG2 after insult (arrows). However, large numbers of OX42⁺ cells in the field did not express NG2 proteoglycan (arrowheads). (J) None of NG2-expressing cells inside the spinal cord tissues appeared fibronectin positive (arrows). Scale bars for G−J = 50 μm,