大鼠液压冲击脑损伤bFGF及其受体FGFR1 mRNA表达

目的 观察脑损伤后 bFGF及其受体 FGFRl mRNA表达及其时序性变化,探讨脑损伤的分子机制及法医学脑损伤时间推断。方法 用原位杂交(ISH)和RT-PCR技术观察大鼠液压冲击脑损伤后bFGF及FGFRl mRNA在伤后不同时间(30min、1h、3h、6h、12h、1d、3d、7d)的表达情况,以正常大鼠及手术大鼠作为对照。结果(1)正常及手术对照组大鼠脑组织内有低水平的bFGF及FGFRl mRNA表达;(2)脑损伤后6h～3d,大脑皮质和脑干bFGF/FGFRl mRNA水平逐渐增加,7d时已有所下降,但仍未恢复到基础水平;(3)海马冲击后3h即开始显著增加,3d开始下降,7d时已恢复到基础水平。结论 脑损伤可诱导bFGF/FGFRl基因表达,机体对脑损伤存在自身保护机制,其表达的时序性改变可望用于法医学脑损伤时间推断。

Level of bFGF and its receptor FGFR1 mRNA in rat brain following injury caused by moderate lateral fluid percussion

Objective Study on the pattern of changes of bFGF and FGFRl mRNA occurred in the experimental brain injury model in order to provide scientific basis for the diagnosis, forensic identification and clinical treatment, and also for further ascertaining the molecular mechanism of brain injury. Methods Male Sprague-Dawley rats were divided into 3 groups: normal control, sham operation, and injury groups. The rats of injury groups were subjected to moderate lateral fluid percussion brain injury (0.2MPa). The injury groups was then subdivided into 30min, 1h, 3h, 6h, 12h, 1d, 3d and 7d groups according to the time elapsed after injury. In situ hybridization (ISH) and RT-PCR were used for studying the mRNA expression of both bFGF and FGFRl factors. Results (1) In the brain of normal control and sham operation control groups, mRNA levels of bFGF and FGFRl were low; (2) There is gradual increase of bFGF and FGFRl mRNA levels could be observed 6h to 3d after injury both in cortex and brain stem, then partly declined at 7d; (3) In hippocampus, the gradual increase occurred during 3h- 1d after injury, then partly declined at 3d, and returned to basal level at 7d. Conclusions The results suggested that brain injury induced the gene expressions of bFGF and FGFR1. The bFGF may contribute to maintenance of nerve cell survival and the repair of damaged neural tissues after CNS injury and the patterns of their level change were quite regular. It is potentially useful for timing of injury in forensic medical practice.