美國科學(xué)家的一項最新研究發(fā)現(xiàn)，將人類臍帶血細胞（umbilical cord blood cells,，UCBC）注射入老齡大鼠后，它們大腦海馬區(qū)的微環(huán)境會得到改善,，同時神經(jīng)干細胞（或前體細胞）也得到相應(yīng)的恢復(fù),。這一研究成果開啟了利用細胞療法應(yīng)對大腦衰老的可能性。相關(guān)論文在線發(fā)表于《BMC神經(jīng)科學(xué)》雜志上,。
領(lǐng)導(dǎo)該項研究的是美國南佛羅里達大學(xué)（USF）的Carmelina Gemma,。他表示，伴隨著衰老的神經(jīng)發(fā)生減少主要是干細胞增殖衰減的結(jié)果,。論文作者之一,、USF衰老與大腦修復(fù)卓越研究中心的Alison Willing博士說，“隨著年齡的增加,，腦細胞神經(jīng)發(fā)生會顯著減少,，這很大程度上是由大腦微環(huán)境的逐漸損耗、困乏引起的,。而在注射臍帶血細胞后,，很可能是由于炎癥的減少,，我們看到了情況有所改善。”
論文第一作者Adam Bachstetter表示,，“大腦中存在兩個干細胞池,，其中一個就在海馬區(qū)。與體內(nèi)其它干細胞池相似,，大腦的干細胞也會逐漸喪失生成新細胞的能力,，而炎癥是一個重要的壓力刺激因素。”
在此前的研究中,，由USF另一位科學(xué)家Paula C. Bickford領(lǐng)導(dǎo)的小組發(fā)現(xiàn),，通過阻斷前炎性細胞因子（pro-inflammatory cytokine）IL1B可以減少衰老大鼠的神經(jīng)炎癥，從而部分挽救由衰老引發(fā)的神經(jīng)發(fā)生減少,，并改善大腦的認知功能,。
對于最新的研究，Bickford說,，“我想臍帶血細胞可能具有類似的潛在作用,，減少炎癥并恢復(fù)神經(jīng)干細胞或前體細胞失去的能力——增殖以及分化成神經(jīng)元。”
研究發(fā)現(xiàn),，在臍帶血細胞注入大鼠后的24小時內(nèi),，它們大腦中增殖細胞的數(shù)量就會提升，而這樣一次處理可以令細胞增殖處于“加強”狀態(tài)至少15天的時間,。
另一位論文作者,、USF衰老與大腦修復(fù)卓越研究中心主任Paul R. Sanberg總結(jié)道，“實驗表明注射臍帶血細胞可以減少神經(jīng)炎癥,。這一結(jié)論無疑提升了細胞治療作為一種有效方法,，用于改善老化大腦微環(huán)境并部分恢復(fù)其已損失能力的可能性。”（科學(xué)網(wǎng) 任霄鵬/編譯）
生物谷推薦原始出處：
（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
