The mechanism of mesenchymal stem cells on neural function in rats with traumatic brain injury

Abstract

Objective To investigate the effect of mesenchymal stem cells (MSCs) on the neurological function of rats with traumatic brain injury, and to investigate the mechanism of the effect of MSCs. Methods 60 SD rats models with brain injury established by the modified Feeney method were divided into model group, MSCs group and phosphate buffer (PBS) group by. Another 20 healthy SD rats were chosen as the control group. Rats of MSCs group were transplantated with Umbilical cord mesenchymal stem cells isolated and cultured in vitro. Neurological function of rats in each group were evaluated by improved neurological function score (mNSS) standard at 1, 3, 7, 14, 21, 28 d after transplantation. Neuronal nuclear antigen (NeuN) expression level in the brain tissue of rats was detected with immunohistochemical method. Brain-derived neurotrophic factor (BDNF) mRNA level of in the brain tissue of rats was detected with reverse transcriptase-polymerase chain reaction (RT-PCR) method. The apoptosis level of cerebral tissue cells in rats was detected by TdT-mediated dUTP nick end labeling (TUNEL) method. Results Compared with the control group, mNSS score of rats in model group, MSCs group and PBS group increased, NeuN expression decreased increased (P=0.000). Compared with the model group and PBS group, mNSS score of rats in MSCs group significantly decreased, NeuN expression significantly decreased(P=0.000). Compared with the control group BDNF mRNA level (0.31±0.12), BDNF mRNA level in model group, PBS group and MSCs Group (1.32±0.34, 1.23±0.30, 0.81±0.21) significantly increased (P=0.000). Compared with model group and PBS group, the levels of BDNF mRNA in MSCs group significantly reduced (P=0.014, P=0.019). Compared with the apoptosis level of brain tissue in control group (3.14±1.12), apoptosis level in model group, PBS group and MSCs group (27.84±4.32, 25.35±4.89, 10.33±3.32) significantly increased (P=0.000). Compared with model group and PBS group, the level of apoptosis in brain tissue of MSCs group significantly decreased (P=0.000). Conclusion Mesenchymal stem cells can decreased the apoptosis level of brain injury in rats through the mechanism of repairing damaged neurons and promoting the BDNF secretion. It can promote the repair effect on neural function of rats with traumatic brain injury. Key words: Brain injury; Mesenchymal stem cells; Nerve function