The impact of bone marrow-derived mesenchymal stem cells on neovascularisation in rats with brain injury

Introduction
The impact of bone marrow-derived mesenchymal stem cells (BM-MSCs) on neovascularisation in rats with craniocerebral injury (CI) was investigated.

Material and methods
The rate CI model was established by the free-fall method, and then rats were randomly divided into a transplanted group (EG) and a control group (CG). Rats in the transplanted group were injected with BM-MSCs in the lateral ventricle, while those in the control group were injected with normal saline. Modified neuro­logical severity scores (mNSSs) were compared. Furthermore, CD34+CD133 double-labelled cells (CD34+CD133+ cells) in the peripheral blood and expression of CD31 and neuron-specific enolase in injured tissues were detected.

Results
There were significant intra- and intergroup differences in modified neurological severity scores at different time points. The number of CD34+CD133+ cells in the peripheral blood of CG initially decreased, but it increased later and peaked 6 h after injury, then gradually decreased and returned to normal 24 h after injury. Cells in the periphe­ral blood of EG continued to increase until 24 h after injury, reaching a number higher than that in CG (p < 0.05). The postoperative expression of neuron-specific enolase in EG was higher than that in CG (p < 0.05). The positive expression of CD31 was lower in the two groups before surgery, but the expression in EG was higher than that in CG after surgery (p < 0.05).

Conclusions
Bone marrow-derived mesenchymal stem cells transplantation can increase the number of endothelial progenitor cells in the peripheral blood of rats with traumatic brain injury and increase the expression of peripheral angiogenetic markers and neuronal markers. The neurological function in EG improved significantly compared to that of CG.