Figure 3

Sustained static compression induces a disproportionately large decrease in intervertebral disc cells with a notochordal phenotype. (A) Representative hematoxylin and eosin sections and immunofluorescent sections for cytokeratin-8, galectin-3, 4′,6-diamidino-2-phenylindole (DAPI), and merged signals in the loaded disc nucleus pulposus (NP) and annulus fibrosus (AF) at 0, 7, 28, and 56 days of loading (bars, 200 μm). (B) Changes in the population of DAPI-positive total cells and cytokeratin-8- and galectin-3-co-positive cells, identified as notochordal cells, in the NP and AF at 0, 7, 28, and 56 days of loading. Data are mean ± standard deviation (n = 6). Two-way analysis of variance with the Tukey-Kramer post hoc test was used. *P < 0.05 when compared between loaded and unloaded conditions. ^†P < 0.05 when compared between different time points.