Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model

Abstract

BACKGROUND Hematopoietic stem cells transplantation has high clinical potential against a wide variety of hematologic, metabolic, and autoimmune diseases and solid tumors. Clinically, hematopoietic stem cells derived from peripheral blood are currently used more than those obtained from sources such as bone marrow. However, mobilizing agents used in the clinic tend to fail in high rates, making the number of mobilized cells insufficient for transplantation. We investigated whether sodium caseinate induces functional mobilization of hematopoietic stem cells into peripheral blood of Balb/c mice. MATERIAL AND METHODS Using a mouse model, we administrated sodium caseinate or Plerixafor, a commercial mobilizing agent, and analyzed counts of hematopoietic stem cells in peripheral blood, and then cells were transplanted into lethally irradiated mice to restore hematopoiesis. All assays were performed at least twice. RESULTS We found that sodium caseinate increases the number of mononuclear cells in peripheral blood with the immunophenotype of hematopoietic stem cells (0.2 to 0.5% LSK cells), allowing them to form colonies of various cell lineages in semisolid medium (p<0.05). This effect is similar to that of Plerixafor, and cells transplanted into lethally irradiated mice can restore hematopoiesis at higher percentages than mononuclear cells mobilized by Plerixafor (40% vs. 20%, respectively). Further, a secondary transplant rescued a separate group of irradiated mice from death, proving definitive evidence of hematopoietic reconstitution after hematopoietic stem cells transplantation. Data are presented as mean ± standard deviation. To determine significant differences between the data, one-way ANOVA and the Tukey test were used. CONCLUSIONS Collectively these results show the utility of sodium caseinate as a mobilizer of hematopoietic stem cells and its potential clinical application in transplantation settings.

Figure 1

Count of mononuclear cells obtained from peripheral blood (WBC on PB) of Balb/c mice treated with vehicle (PBS), CasNa (0.1 g/mL), or Plerixafor (5 mg/kg). * P<0.05, error bars represent standard deviation.

Figure 2

Mononuclear cells from peripheral blood stained for HSCs (lineage negative, Sca-1+ and C-kit+) obtained from mice treated with vehicle (PBS), CasNa (0.1 g/mL), or Plerixafor (5 mg/kg).

Figure 3

Colony-forming units (CFU) from mononuclear cells obtained from peripheral blood of mice treated with vehicle (BALB/c-PBS), 0.1 g/mL of CasNa (BALB/c-CasNa), or 5 mg/kg of Plerixafor (BALB/c-AMD3100). GM (granulocyte-macrophage). * P<0.05, and error bars represent standard deviation.

Figure 4

Survival analysis of lethally irradiated BALB/c mice receiving peripheral mononuclear cells mobilized by vehicle (PB-MNC of BALB/c-PBS), 0.1 g/mL of CasNa (PB-MNC of BALB/c-CasNa), or 5 mg/kg Plerixafor (PB-MNC of BALB/c-Plerixafor). Each group contains 5 mice. Kaplan-Meier analysis was performed over 22 weeks. * P<0.05 compared with BALB/c-PBS.

Figure 5

Colony-forming units (CFU) from mononuclear cells (MNC) obtained from bone marrow of surviving BALB/c mice transplanted with MNCs of peripheral blood from CasNa-treatment mice (Figure 4) or transplanted with MNCs obtained from bone marrow of healthy mice (BM-MNC of BALB/c). * P<0.05, error bars represent standard deviation. BM-MNC of surviving BALB/c transplants, contains 2 mice.

Figure 6

Survival analysis of lethally irradiated Balb/c mice receiving mononuclear cells of bone marrow of health BALB/c mice (BM-MNC of BALB/c) or bone marrow of surviving Balb/c mice transplanted with peripheral MNC mobilized by CasNa. (Figure 4). Each group contains 5 mice. Kaplan-Meier analysis.