Effect of bone marrow mesenchymal stem cells on angiogenesis in rats after brain injury

Abstract

To explore the effect of bone marrow mesenchymal stem cells (BM-MSCs) on angiogenesis in rats after brain injury. Brain injury model of rats was established with freely fall method. A total of 50 Sprague-Dawley (SD) rats were randomly divided into a transplanted group and a control group (n=25 in each group). BM-MSCs were injected in lateral ventricle in the transplanted group, and normal saline was injected in the control group. Modified method for neurological deficit scores (mNSS) was performed at the 1, 3, 7, 21, 14 d after the operation. Flow cytometry were performed to detect CD34 and CD133 double-labeled peripheral blood cells in preoperative or 3, 6, 12, 24 h, and 3, 7 d after the operation. Expression of neuron-specific enolase (NSE) and CD31 in the brain tissues near injury area was detected by immunohistochemical SP method. There was significant difference in the MNSS scores between the 2 groups (F=5.997, P<0.05), and the difference at the different time points in each group was significant (F=37.106, P<0.01). The mNSS scores in the control group were higher than those in the transplanted group at the 7, 14, 21 d after the operation (P<0.05). The CD34 and CDl33 double positive cells (DPCs) were present in rats' peripheral blood. DPCs's numbers in peripheral blood in the control group were declined at 3 h after the sugery, they were increased and reached the highest point at 6 h after the surgery, and decreased gradually and reached normal levels at 24 h after the surgery. The same tendency was achieved in the transplanted group, and the DPCs's numbers were increased until 24 h after the surgery, which were significantly higher in the transplanted group than those in the control group at 24 h after the surgery (P<0.05). The NSE expression in the transplanted group was significantly greater than that in the control group in 7 and 14 d after the surgery (P<0.05). The expression of CD31 in the transplanted group was significantly higher than that in the control group in 3 and 7 d after the surgery (P<0.05). BM-MSCs transplantation can increase the number of peripheral blood endothelial progenitor cells after traumatic brain injury in rats and sustain for 24 h, which in turn up-regulate the angiogenesis and neuronal marker, and improve the neurological function.