RhoA/ROCK pathway of neural stem cells under mild hypothermia / 中国组织工程研究

ABSTRACT

BACKGROUND:Mild hypothermia can effectively ease secondary brain and spinal cord injuries, which has a definite protective effect on the central nervous system. Meanwhile, mild hypothermia is conducive to the proliferation, activation and growth of transplanted cells by improving the microenvironment of the injured spinal cord.OBJECTIVE:To investigate whether mild hypothermia intervention can regulate the proliferation and apoptosis of neural stem cells through the RhoA/ROCK pathway.METHODS:The neural stem cell injury model was prepared and randomly divided into two groupsnormothermia group and mild hypothermia group. The mild hypothermia group was treated with mild hypothermia [(32.0±0.5) ℃] for 4 hours. Expression of RhoA, RHOCK, Nogo-A and NgR in neural stem cells was detected by RT-PCR and western blot assay. RhoA/RHOCK positive cells were observed by fluorescence microscope. The intracellular Ca2+ concentration in neurons was measured by laser scanning confocal microscopy.RESULTS AND CONCLUSION:The expression of RhoA, RHOCK, Nogo-A and NgR in neural stem cells at mRNA and protein levels was significantly lower in mild hypothermia group than in the normothermia group (P < 0.05). The intracellular Ca2+ concentration in the neural stem cells was lower in the mild hypothermia group than in the normothermia group (P < 0.05). The number of RhoA/RHOCK positive cells in the brain tissue of rats was significantly lower in the mild hypothermia group than in the in the mild hypothermia group (P < 0.05). To conclude, mild hypothermia regulates the proliferation and apoptosis of neural stem cells by inhibiting the RhoA/ROCK pathway.