Walton M, Young D, Sirimanne E, Dodd J, Christie D, Williams C, Gluckman P, Dragunow M
Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine and Health Science, University of Auckland, New Zealand.
Brain Res Mol Brain Res. 1996 Jul;39(1-2):137-52. doi: 10.1016/0169-328x(96)00019-8.
A unilateral hypoxic-ischemic (HI) insult in the 21 day old rat has been used to assess the role of clusterin in nerve cell death. Both clusterin mRNA and protein levels were measured at various time points after moderate (15 min) and severe (60 min) HI insult using in situ hybridisation and immunocytochemistry respectively. The severe HI insult lead primarily to necrotic neuronal death and showed very little if any clusterin mRNA and protein induction on the ligated side of the brain. However, following the moderate HI insult there was a dramatic time-dependent accumulation of clusterin protein in neurons of the CA1-CA2 pyramidal cell layers in the hippocampus and cortical layers 3-5, regions undergoing delayed neuronal death. Clusterin mRNA expression, in contrast to neuronal protein accumulation, appeared to be glial in origin (probably astrocytes) with increases in mRNA in and around the hippocampal fissure and only a weak signal over the CA1-CA2 pyramidal cell layer. These results support the hypothesis that the clusterin protein is synthesised in the astrocytes, secreted and then taken up by dying neurons. Clusterin immunoreactivity and in situ DNA end-labelling performed on the same sections revealed that clusterin was accumulating in neurons destined to die by programmed cell death. However the relative time-courses of DNA fragmentation and clusterin immunoreactivity suggest that clusterin production was a result of the selective delayed neuronal death rather than being involved in the biochemical cascade of events that cause it.
21日龄大鼠的单侧缺氧缺血性（HI）损伤已被用于评估簇集蛋白在神经细胞死亡中的作用。分别使用原位杂交和免疫细胞化学技术，在中度（15分钟）和重度（60分钟）HI损伤后的不同时间点测量簇集蛋白的mRNA和蛋白质水平。重度HI损伤主要导致坏死性神经元死亡，并且在脑结扎侧几乎没有（如果有的话）簇集蛋白mRNA和蛋白质的诱导表达。然而，中度HI损伤后，在海马体CA1-CA2锥体细胞层和皮质3-5层（经历延迟性神经元死亡的区域）的神经元中，簇集蛋白呈时间依赖性显著积累。与神经元蛋白积累不同，簇集蛋白mRNA表达似乎起源于神经胶质细胞（可能是星形胶质细胞），在海马裂及其周围mRNA增加，而在CA1-CA2锥体细胞层仅有微弱信号。这些结果支持以下假说：簇集蛋白由星形胶质细胞合成、分泌，然后被濒死神经元摄取。在同一切片上进行的簇集蛋白免疫反应性和原位DNA末端标记显示，簇集蛋白在注定通过程序性细胞死亡而死亡的神经元中积累。然而，DNA片段化和簇集蛋白免疫反应性的相对时间进程表明，簇集蛋白的产生是选择性延迟神经元死亡的结果，而非参与导致这种死亡的生化事件级联反应。
