Mesenchymal stem cells (MSCs) have emerged in recent years as beneficial tools for cell therapy and autologous/allogeneic transplantation and their clinical harnessing considers the bone marrow (BM) and peripheral blood (PB). However, this requires a process of endogenous mobilization that offers a non-invasive alternative. Thus, granulocyte colony-stimulating factor (G-CSF) and AMD3100 (Plerixafor®) are well known and clinically approved to stimulate MSCs mobilization, but data on their potential activity in MSCs mobilization are still scarce.

Evaluate the influence of G-CSF and AMD3100 stimulation on MSCs mobilization from BM to PB in BALB/c mice.

For this study, 45 male BALB/c mice aged 3-4 weeks were used. They were divided into 5 groups: PBS+PBS control group (CG, n = 9), PBS+GCSF group (n = 9), PBS+AMD3100 group (n = 9), G-CSF+PBS group (n = 9) and G-CSF+AMD3100 group (n = 9). Pre-treatment was performed with intraperitoneal (i.p.) injections of phosphate-buffered saline (PBS, 160 μl/i.p.) or G-CSF (200 μg/kg/i.p.) for 4 consecutive days. On day 5 (D5), 24 hours after the last injection of PBS or G-CSF, mice were also injected with PBS or AMD3100 (5 mg/kg/i.p.). After 1 hour, BM and PB samples were subsequently collected. The mobilized CD14+CD73+CD90+CD105+ MSCs were then evaluated ex vivo using Flow Cytometry. Statistical analyzes were performed through GraphPad Prism (v.5) using One-way ANOVA test with Tukey's post-test.

Based on this study, it was found that there were no statistically significant differences for MSCs mobilization in the BM in any of the studied groups; however, the PBS+AMD3100 group had the highest rate of MSCs enrichment within the BM. Notably, mice of the G-CSF+PBS group exhibited the highest rate of MSCs mobilization in the PB when compared to the CG (p < 0.0001), while the G-CSF+AMD3100 group showed no statistically significant difference for MSCs mobilization in PB. Furthermore, the mice of the PBS+G-CSF group and the PBS+AMD3100 group did not exhibit a significant increase in MSCs mobilization in the PB.

With these results, it is verified that the pre-treatment with G-CSF is the most suitable to induce the MSCs mobilization to PB in a dose-dependent manner. Our data demonstrated that AMD3100 proved not to be suitable for MSCs mobilization in both BM and PB.

FAPEAM, CAPES and CNPq.