Figure 2.

Parathyroid hormone enhances mesenchymal stem cell migration to vertebral defects. (a) Human mesenchymal stem cells (hMSCs) were transduced with the lentiviral vector harboring the reporter gene Luciferase2 (hMSC-Luc2). Representative in vitro bioluminescence imaging (BLI) of three confluent hMSC-Luc2 seeded wells (left) compared to three background wells without cells (right) is shown. (b) Luciferase2 expression was quantified based on in vitro BLI over six passages. Data are shown as mean + SEM (n = 5). One-way ANOVA with Bonferroni correction for multiple comparisons was preformed; n.s., not significant. (c) hMSC-Luc2 migration to vertebral defects was tracked over 8 weeks after the first cell injection and quantified by measuring the bioluminescent signal overlying the vertebral defects. Representative images of all three groups treated with hMSC-Luc2 (without PTH, ldPTH, and hdPTH) taken on postoperative day 14 are presented along the scale of the total flux. The red circle on the representative images indicates the region of interest in the lumbar spine proximity that was analyzed. (d) The average cumulative total flux (Σ total flux) up to each time point was calculated per animal. Data are shown as mean + SEM (n = 5 for each group). Repeated-measures two-way ANOVA with bonferroni correction for multiple comparisons was preformed. *P < 0.05; **P < 0.01; ***P < 0.001; and ****P < 0.0001.