美国加利福尼亚大学欧文分校的研究人员培育出患脑瘤的实验鼠，并对它们的脑部进行放疗，实验鼠的认知能力因而受到损伤。放疗两天后，研究人员向它们的脑部植入人类神经干细胞，在随后1个月及4个月的评估中，这批实验鼠的认知能力都得到改善，而未接受移植的对照组实验鼠，其受损认知能力未发生变化。

研究人员发现，移植10万个神经干细胞就足以提高实验鼠的认知能力。移植后存活的神经干细胞中有15％转化为新的神经细胞，另有45％转化为星形胶质细胞和少突细胞。星形胶质细胞是脑内神经胶质细胞的一种，这类细胞有保护神经细胞并将血液中的养分提供给神经细胞的作用。少突细胞是一种神经胶质细胞，它负责制造一种称为髓磷脂的物质，形成包裹神经细胞的髓鞘。

这项研究成果已发表在美国学术刊物《癌症研究》上。领导该研究的放射肿瘤学教授查尔斯·利莫利说，上述发现提供的证据表明，神经干细胞可以用来逆转大脑中健康组织因放疗受到的损伤。

原文出处：

Cancer Rresearch   doi: 10.1158/0008-5472.CAN-11-0027

Human Neural Stem Cell Transplantation Ameliorates Radiation-Induced Cognitive Dysfunction

Munjal M. Acharya, Lori-Ann Christie, Mary L. Lan, Erich Giedzinski, John R. Fike, Susanna Rosi, and Charles L. Limoli

Cranial radiotherapy induces progressive and debilitating declines in cognition that may, in part, be caused by the depletion of neural stem cells. The potential of using stem cell replacement as a strategy to combat radiation-induced cognitive decline was addressed by irradiating athymic nude rats followed 2 days later by intrahippocampal transplantation with human neural stem cells (hNSC). Measures of cognitive performance, hNSC survival, and phenotypic fate were assessed at 1 and 4 months after irradiation. Irradiated animals engrafted with hNSCs showed significantly less decline in cognitive function than irradiated, sham-engrafted animals and acted indistinguishably from unirradiated controls. Unbiased stereology revealed that 23% and 12% of the engrafted cells survived 1 and 4 months after transplantation, respectively. Engrafted cells migrated extensively, differentiated along glial and neuronal lineages, and expressed the activity-regulated cytoskeleton-associated protein (Arc), suggesting their capability to functionally integrate into the hippocampus. These data show that hNSCs afford a promising strategy for functionally restoring cognition in irradiated animals. Cancer Res; 71(14); 4834–45. ?2011 AACR.