脑缺血再灌注损伤中前体神经生长因子和成熟体神经生长因子及其受体的表达

实验观察脑缺血再灌注损伤中，前体神经生长因子和成熟体神经生长因子在缺血区皮质和非缺血区皮质的表达。结果发现在缺血区和非缺血区皮质中，前体神经生长因子表达在细胞外和胞浆，成熟体神经生长因子极低少量表达在细胞外。缺血侧皮质前体神经生长因子表达显著下降，至1d时达到最低值，成熟体神经生长因子在4h时表达增加，至3d时达到最低值，神经生长因子受体(p75NTR)在缺血后表达明显降低，至3d时达到峰值。证实脑缺血再灌注损伤的病理过程中：①前体神经生长因子是神经生长因子存在的主要形式。②脑缺血再灌注损伤影响了前体神经生长因子向成熟体神经生长因子的转化过程。③ 前体神经生长因子/p75NTR可能参与了缺血后的再灌注损伤。

Expression of nerve growth factor precursor, mature nerve growth factor and their receptors during cerebral ischemia-reperfusion injury

We investigated nerve growth factor precursor (proNGF) and mature NGF expression in ischemic and non-ischemic cortices after cerebral ischemia-reperfusion injury. In both ischemic and non-ischemic cortices, proNGF was found to be present in the extracellular space and cytoplasm. In addition, mature NGF was expressed in extracellular space, but with a very low signal. In ischemic cortex only, proNGF was significantly decreased, reaching a minimal level at 1 day. Mature NGF was increased at 4 hours, then reached a minimal level at 3 days. The p75 neurotrophin receptor (p75NTR) was significantly decreased after ischemia, and increased at 3 days after ischemia. These results confirmed that proNGF was the predominant form of NGF during the pathological process of cerebral ischemia-reperfusion injury. In addition, our findings suggest that ischemic injury may influence the conversion of proNGF to mature NGF, and that proNGF/p75NTR may be involved in reperfusion injury.