Protective effect of exogenous cardiotrophin-1(CT-1) against spinal cord injury in rats / 第二军医大学学报

ABSTRACT

Objective: To investigate the protective effect of exogenous cardiotrophi-1 (CT-1) against spinal cord injury and the possible mechanism. Methods: Ninety rats were evenly randomized into 9 groups, namely, before injury (0 h) and 1, 6, 12 hours, 1, 2, 3, 6 and 12 days after injury. RT-PCR was used to examine the expression of CT-1, its receptor gp130, and leukemia inhibitory factor receptor (LIFR) in the injured spinal cord tissues. Rats were also divided into spinal cord injury model group, nerve growth factor (NGF) treatment group and CT-1 treatment group, receiving intradural infusion of normal saline, NGF, and rhCT-1(100 μg·k-1·-1), respectively; the injured tissues were harvested at the 3rd day, one week and 2 weeks after injury for H-E and Nissl staining; and the neuron counts were compared between different groups. Sixty rats were divided into model group and CT-1 treatment group (n=30); the triceps muscle wet weight and total protein weight were compared between the two groups at 1 week, 2 weeks and 4 weeks after spinal cord injury. Results: CT-1 mRNA expression had a transient significant increase after injury (P<0.05), and then it decreased gradually; meanwhile, expression of its receptors increased consequently. The numbers of neurons and Nissl bodies were similar in CT-1-treated group and NGF-treated group, but the numbers of both groups were significantly more than that in the model control group (P<0.05). In addition, the muscle wet weight and protein content in the CT-1-treated group were significantly higher than that in the model control group at 4 weeks and 12 weeks after injury (P<0.05). Conclusion: CT-1 exhibits a protective effect on the survival and function of neurons after spinal cord injury in rats.