Figure 7. Adoptive transfer confirms MMP-dependent migration of myeloid cells into the injured cord. Interestingly, there are very few GFP+ cells in the meninges in the vehicle-treated group (A), whereas there was an abundance of these cells in the meninges in the SB-3CT-treated group (B). At 24 h after adoptive transfer, most of the infiltrated GFP+ cells were CD11b+Gr1+ cells, which are characteristic of immature myeloid cells (C, D). However, by 48 h after transfer, many of the infiltrated GFP+ cells were Ly6G− (E). At 72 h after transfer, the cell bodies of the infiltrated GFP+ cells assumed a larger phenotype relative to those seen at 24 h after transfer and were F4/80+ (F). The presence of infiltrated GFP+ cells within the injured site was confirmed by immunostaining with anti-GFP antibody 24 h after transfer (G–J). Treatment with the MMP inhibitor SB-3CT or CXCR4 inhibitor AMD3100 reduced the number of adoptively transferred bone marrow-derived myeloid cells that were recruited to the injured cord to 70%, and further reduced to 55% when treated with SB-3CT and AMD3100 together (N = 5/group) (K). *p < 0.05, **p < 0.01. Scale bars: 50 μm (A, B, G–J), 100 μm (C–F).