Fig. 4

Engraftment of hNTSCs in inflamed joint tissues. (A) DiR dye-labeled hNTSCs (#10, #433), hNDFs (normal human dermal fibroblasts) (1 × 10⁶ cells/site), or DiR dye-only was injected into the ankle joint of mice at 8 weeks after primary immunization. DiR signal was measured weekly by optical in vivo imaging until no more signal was detected. (B) mRNA levels of various chemokine receptors in hNTSCs. hNTSCs were stimulated by medium alone or 10 ng/mL of IL-1β or TNF-α for 72 h. The mRNA levels of chemokine receptors were determined by real-time PCR. The numbers represent the relative ratio of mRNA levels in hNTSCs stimulated by IL-1β or TNF-α. (C) hNTSCs migrated in vitro according to the chemokine gradient. A Boyden chamber assay was performed to assess the migration capacity of hNTSCs stimulated with SDF-1, IL-8, or IP-10, as described in the Materials and Methods section. The chemokine concentration was 150 ng/mL. Cells were incubated for 6 h, fixed, and stained with DiffQuik. Migrated NTSCs were analyzed by pixels using ImageJ software. Scale bar: 200 μm. The data are expressed as the mean ± SD. **P < 0.01.