美国科学家的一项最新研究发现,将人类脐带血细胞(umbilical cord blood cells,UCBC)注射入老龄大鼠后,它们大脑海马区的微环境会得到改善,同时神经干细胞(或前体细胞)也得到相应的恢复。这一研究成果开启了利用细胞疗法应对大脑衰老的可能性。相关论文在线发表于《BMC神经科学》杂志上。
领导该项研究的是美国南佛罗里达大学(USF)的Carmelina Gemma。他表示,伴随着衰老的神经发生减少主要是干细胞增殖衰减的结果。论文作者之一、USF衰老与大脑修复卓越研究中心的Alison Willing博士说,“随着年龄的增加,脑细胞神经发生会显著减少,这很大程度上是由大脑微环境的逐渐损耗、困乏引起的。而在注射脐带血细胞后,很可能是由于炎症的减少,我们看到了情况有所改善。”
论文第一作者Adam Bachstetter表示,“大脑中存在两个干细胞池,其中一个就在海马区。与体内其它干细胞池相似,大脑的干细胞也会逐渐丧失生成新细胞的能力,而炎症是一个重要的压力刺激因素。”
在此前的研究中,由USF另一位科学家Paula C. Bickford领导的小组发现,通过阻断前炎性细胞因子(pro-inflammatory cytokine)IL1B可以减少衰老大鼠的神经炎症,从而部分挽救由衰老引发的神经发生减少,并改善大脑的认知功能。
对于最新的研究,Bickford说,“我想脐带血细胞可能具有类似的潜在作用,减少炎症并恢复神经干细胞或前体细胞失去的能力——增殖以及分化成神经元。”
研究发现,在脐带血细胞注入大鼠后的24小时内,它们大脑中增殖细胞的数量就会提升,而这样一次处理可以令细胞增殖处于“加强”状态至少15天的时间。
另一位论文作者、USF衰老与大脑修复卓越研究中心主任Paul R. Sanberg总结道,“实验表明注射脐带血细胞可以减少神经炎症。这一结论无疑提升了细胞治疗作为一种有效方法,用于改善老化大脑微环境并部分恢复其已损失能力的可能性。”(科学网 任霄鹏/编译)
生物谷推荐原始出处:
(BMC Neuroscience),doi:10.1186/1471-2202-9-22,Adam D Bachstetter, Carmelina Gemma
Peripheral injection of human umbilical cord blood stimulates neurogenesis in the aged rat brain
Adam D Bachstetter , Mibel M Pabon , Michael J Cole , Charles E Hudson , Paul R Sanberg , Alison E Willing , Paula C Bickford and Carmelina Gemma
Abstract (provisional)
Background
Neurogenesis continues to occur throughout life but dramatically decreases with increasing age. This decrease is mostly related to a decline in proliferative activity as a result of an impoverishment of the microenvironment of the aged brain, including a reduction in trophic factors and increased inflammation.
Results
We determined that human umbilical cord blood mononuclear cells (UCBMC) given peripherally, by an intravenous injection, could rejuvenate the proliferative activity of the aged neural stem/progenitor cells. This increase in proliferation lasted for at least 15 days after the delivery of the UCBMC. Along with the increase in proliferation following UCBMC treatment, an increase in neurogenesis was also found in the aged animals. The increase in neurogenesis as a result of UCBMC treatment seemed to be due to a decrease in inflammation, as a decrease in the number of activated microglia was found and this decrease correlated with the increase in neurogenesis.
Conclusion
The results demonstrate that a single intravenous injection of UCBMC in aged rats can significantly improve the microenvironment of the aged hippocampus and rejuvenate the aged neural stem/progenitor cells. Our results raise the possibility of a peripherally administered cell therapy as an effective approach to improve the microenvironment of the aged brain