FIGURE 4.

Blocking LPA₁ activity interferes with podosome belt and sealing zone organizations. A, micrographs of mature osteoclasts (Oc) from Lpar1^−/− and wild type (WT) mice seeded on glass coverslips and stained with rhodamine-conjugated phalloidin (left panels). Percentage of osteoclasts with complete podosome belts (right panels) Bar scale, 200 μm. ¶¶¶, p < 0.001 versus wild type osteoclasts using two-sided unpaired t test. B, micrographs of mature osteoclasts from wild type mice seeded on bone slices and incubated with Ki16425 (10 μm) for 0, 30, and 60 min and stained with Alexa Fluor® 488 phalloidin (upper panels). Percentage of osteoclasts with sealing zones (SZ), with complete sealing zone, and with discontinued sealing zone, and area of sealing zone per osteoclast (lower panels). *, p < 0.05; **, p < 0.01, ***, p < 0.001 versus 0-min-treated cells using one-way ANOVA with Bonferroni post-test. Arrowheads indicate osteoclasts with a complete sealing zone. Arrows indicate osteoclasts with discontinued sealing zones. Bar scale, 100 μm.