Figure 3.

Blocking SDF-1/CXCR4 signaling by AMD3100 attenuated the severity of OA cartilage in Hartley primary OA guinea pig model. The weight of the animals increased gradually with time, with no significant difference among the AMD3100-treated group, 12-month primary OA group, and the sham group at any time (A). India-ink stain revealed typical OA lesions in the primary OA group and PBS-treated group, whereas less staining and fewer fissures were noticed in the AMD3100-treated group (B). H&E and Safranin-O staining showed less cartilage damage for the AMD3100-treated knees as compared with the 12-month primary OA and sham joints. Loss of proteoglycan staining and cartilage destruction was evident in the 12-month primary OA and sham joints (C, D). Guinea pig Mankin score shows no significant difference between the primary OA group and the PBS-treated group on cartilage damage, whereas the cartilage damage in these two groups was much greater than that of the AMD3100-treated group (E). The high concentration of GAG in primary OA and PBS-treated groups was attenuated in the animals treated with AMD3100 (F). Data are expressed as mean ± SD. AMD3100 group, n = 13; primary OA group, n = 11; PBS group, n = 11. *P < 0.05.