The effects of TGF-β1 on the apoptosis of nerve cells after spinal cord injury in rats

Objective To investigate the effects of exogenous transforming growth factor β1 on the apoptosis of nerve cells and its functions following spinal cord injury in rats.Methods Ninety-six male Wistar rats were randomly divided into 4 groups:group A (control group),group B (spinal cord injured group),group C (spinal cord injuried +TGF-β1 treated group),group D (spinal cord injuried +anti-TGF-β1 treated group).The rat model of spinal cord injury was found by the Allen's method.In group C and D,drugs were injected into subarachnoid cavity continuously by minipump.The changes of spinal cord were observed by HE staining.Nerve cells apoptosis was detected by transferase-medi-ated dUTP nick end labeling (TNUEL) method and the expression of cell apoptosis factor Fas by immunohistochemistry staining.Functional recovery of hind limbs was measured by Basso-Beattie-Bresnahan locomotor open field behavioral rating test.Results The expression of TGF-β1and Fas increased following spinal cord injury.The amount of TGF-β1and Fas reached the peak 7days and 1day after injury.The apoptosis of neuron had increased and peaked 8 hours after injury.The apoptosis of neuroglia cells had increased and peaked 7 dayss after injury.The slight changes was found in spinal cord in group C.Both of the number of apoptosis of nerve cells and expression of the apoptosis factor (Fas) decreased significantly; compare with group B and D.The BBB score was higher in group C than that in group B and D.Conclusion TGF-β1 can improve the functional recovery of spinal cord by inhibiting the nerve cell apoptosis after the spinal cord injury. Key words: Spinal cord injuries;  Transforming growth factor-batal;  Apoptosis