BFGF Regulates The Differentiation Of Neural Stem Cells Transplanted Into Injured Spinal Cord In Rats

Objectives: To evaluate the functional recovery of acute spinal cord injuried rats treated with transplantation neural stem cells and to study the effects of basic fibroblast growth factor(bFGF) on the experimental acute spinal cord injury and the neural stem cells that transplantated to it.Methods:In The center of molecule biology of Fujian Medical University,Neural stem cells were isolated,cultured and detected. Spinal cord injury (SCI) model was built by revised Allen method. The transplantation of BrdU-labeled cultured cells was performed immediately after injury. The bFGF-treated rats were received 3ul bFGF solution (900ng/ul) at once, 24, 48,72and 96 hours after injury, and an equal volume of normal saline was given to the control group at the same time. CBS scores were checked every two days to show the motor function recovery. 6 weeks postinjured the injured spinal cord was removed and detected by morphological observation and submitted to immunohistochemistry of glial fibrillary acidic protein (GFAP), MAP2 and CNP, markers for astrocytes ,neuron and microglia,as well as of basic fibroblast growth factor (bFGF) and BrdU. Results: ①.Cells isolated from spinal cord of neonatal rats express Nestin antigen and have the potential to form and differentiate into neurns,gliacytes. ②. The expression of bFGF and the number of bFGF positive cell showed increased tendency from 2d to 12th, and decreased at 18th. ③. Subjects treated with bFGF had pronounced recovery of hindlimb movements from 2 to 6 weeks compared to controls, ④. large numbers of BrdU-labeled stem cells were observed in control spinal cord, but No BrdU-positive astrocytes ,neurons or oligodendrocytes were observed. bFGF-treated spinal cords showed BrdU-positive astrocytes. ⑤ . Animals treated with NSCs had no pronounced recovery of hindlimb movements compared to controls .Conclusions:①.The spinal cord of neonatal rats contains stem cells. ②. bFGF plays an important role in the partial recovery of function seen following incomplete contusive spinal cord injury. ③. NSCs can survive and engraft into the contused adult rat spinal cord, but their differentiation is inhibited in the injured spinal cord. ⑤. bFGF can induce engrafted neural stem cells different into astrocytes.