[Erythrocyte removal from bone marrow by density gradient separation using the COBE 2991 cell processor with the triple-bag processing set]

Effect of bone marrow stem cell mobilisation on the expression levels of cellular growth factors in a rat model of acute tubular necrosis

The aim of the present study was to observe the mobilisation effects of stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) on bone marrow stem cells (BMSCs) in rats with renal ischaemia-reperfusion injury. In addition, the effects of the BMSCs on the expression levels of hepatocyte growth factor (HGF) and epidermal growth factor (EGF) were investigated, with the aim to further the understanding of the protective mechanisms of SCF and G-CSF in renal ischaemia-reperfusion injury. The model and treatment groups were established using a model of unilateral renal ischaemia-reperfusion injury, in which the treatment group and the treatment control group were subcutaneously injected once a day with 200 µg/kg SCF and 50 µg/kg G-CSF, 24 h after the modelling, for five consecutive days. The CD34⁺ cell count was measured in the peripheral blood using flow cytometry. The mRNA expression levels of HGF and EGF were determined using polymerase chain reaction analysis, while the protein expression levels of HGF and EGF were detected using immunohistochemistry. The CD34⁺ cell count in the peripheral blood of the treatment and treatment control groups was significantly higher compared with that in the model group (P<0.05). However, CD34 expression levels in the cells from the renal tissues of the model and treatment groups were significantly higher compared with that of the control and treatment control groups (P<0.05), with the greatest increase observed in the treatment group. The mRNA and protein expression levels of HGF and EGF in the treatment group were significantly higher compared with the model group (P<0.05). Therefore, the results indicated that a combination of SCF and G-CSF can promote the repair of acute tubular necrosis. This combination, which can mobilise sufficient numbers of BMSCs to migrate back to the injured site, is a key factor in promoting the repair of renal tubular injury. Upregulation of HGF and EGF was also shown to promote the repair of renal tubular injury.