Mobilization of bone marrow stem cells by G-CSF to accelerate renal regeneration after ischemia reperfusion injury in mice / 中华急诊医学杂志

ABSTRACT

Objective To investigate mobilization of the bone-marrow-derived stem cell (BMSC) into peripheral blood by granulocyte-colony stimulating factor (G-CSF) to accelerate the renal regeneration.Methods Six-week-old transgenic C57BL/6J mice labeled with green fluorescent protein (GFP) as bone marrow donors and C57BL/6 mice without fluorescence label as recipients ( n =20 ) of bone marrow transplantation were used.All recipients received lethal dose of 8.5 Gy total body γ-ray irradiation with 137 Cs before bone marrow transplantation,and the transplantation of bone marrow mononuclear cells 2 × 105 by retrobulbar injection was done two hours later after irradiation. Bone marrow reconstruction after transplantation was proved by flow cytometry five weeks after transplantation.Six weeks after the bone marrow reconstruction completed,left renal pedicles of all mice were cross-clasped for 30 minutes followed by reperfusion to establish the animal model of ischemia-reperfusion injury.Mice were divided into two groups( 1 ) Saline control group ( n =10),saline 0.2 ml/day was injected subcutaneously into chimeric mice from 3 days before to 4 days after operation ; (2) G-CSF mobilization group (n =10),chimeric mice were injected subcutanously with recombinant human G-CSF,200μg/kg/day,once a day from three days before surgery for a week.On the 1st day after mobilization,the percentage of stem cell in non-erythroid cells of peripheral blood was detected by using flow cytometry.One week after ischemia,the homing of BMSC to kidney was identified by flow cytometory.Renal tissue sections were stained with Hemotoxylin and Eosin staining method for pathological study,and the degree of renal tubular injury was analyzed by semiquantitative method of Vyacheslav.Four weeks after ischemia,the differences in degree of renal regeneration between the two groups by analysis the numbers of vascular endothelial cells in the kidney.Results After G-CSF mobilization,the percentage of stem cells with Sca-1 +,c-Kit +,CD29 and CD34 + antigen in peripheral blood in G-CSF mobilization group were higher than those in control group.One week after ischemia,mice of mobilization group showed higher percentage of Sca-1 +,c-Kit + and CD34 + bone marrow derived stem cells in tbe kidney compared to control group (P ＜0.05).One week after ischemia,the tubular epithelial damage score of mobilization group was lower significantly than that of the control group (P ＜ 0.05 ) studied by Hemotoxylin and Eosin staining. Four weeks after ischemia,mice of G-CSF mobilization group showed more CD31 positive cells in the kidney compared to control group (P ＜ 0.05 ).Conclusions G-CSF can effectively mediate the mobilization of bone marrow derived stem cells to peripheral blood and homing to kidney.G-CSF mobilization can accelerate renal regeneration and alleviate the degree of renal histopathological changes after ischemia.