Treatment of traumatic brain injury with endothelial progenitor cells induced from bone marrow mesenchymal stem cells in rats / 中华创伤杂志

ABSTRACT

Objective To observe if endothelial progenitor cells (EPCs) and bone marrow mesenchymal stem cells (BMSCs) could home to the injured region and study the effect of BMSCs-derived EPCs on traumatic brain injury (TBI) in rats.Methods BMSCs were isolated from 3-month-old SD male rats weighing 150 g,and induced to EPCs.EPCs were identified by surface markers CD133,CD34 and FLK-1.A total of 120 female adult SD rats were divided into 3 groups (n =40 each) according to the random probability table method:EPCs group,BMSCs group and 3T3 cells group.The model of moderate to severe TBI was induced by the fluid percussion device.All the cells (i.e.EPCs,BMSCs and 3T3 cells) were injected with BrdU before transplantation to the tail vein of rats.On days 2,7,14 and 28 after transplantation,rat neurological function was evaluated using the modified neurological severity score (mNSS),and injured brain tissue was harvested to detect CD34 and brain-derived neurotrophic factor (BDNF) positive cell density using the immunohistochemistry method.Sry-positive cells were evaluated using the fluorescence in situ hybridization (FISH).Results The positive rate of CD133,CD34 and Flk-1 was 52％,33％ and 38％,indicating BMSCs differentiation towards an EPCs phenotype.On days 7,14 and 28 after transplantation,the mNSS in EPCs group [(10.2 ± 1.5),(8.7 ± 1.0) and (4.9 ± 1.0) points] and in BMSCs group [(10.8 ± 1.7),(10.1 ± 1.7),and (7.2 ± 1.3) points] were lower than that in 3T3 cells group [(12.4 ± 1.5),(1 1.7 ± 1.8),(10.3 ± 1.5) points] (P ＜ 0.05).On 14 and 28 days after transplantation,BrdU-positive CD34 and BDNF in EPCs group were significantly more than those in BMSCs group (P ＜ 0.05).Instead,there were no positive cells in 3T3 cells group.The method of Sry probe to trace the transplanted cells could detect more positive cells compared to the BrdU labeling method.Conclusion Both BMSCs and EPCs can home to the injured region,but EPCs have much better therapeutic effect.