科學家發(fā)現(xiàn)，把來自骨髓的人類干細胞直接注射到小鼠的大腦可以減少中風導致的損傷,。此前的實驗提示注射干細胞可以緩解動物的中風效應,，這可能是由于它誘導了新神經(jīng)元的生長,。
Darwin Prockop及其同事如今發(fā)現(xiàn)注射干細胞可以通過觸發(fā)現(xiàn)有細胞——小膠質細胞（神經(jīng)細胞）和巨噬細胞（免疫細胞）——產生保護神經(jīng)元和減輕炎癥的生化物質從而產生康復作用,。這組科學家證明了注射干細胞可以減少小鼠死亡或損傷的神經(jīng)元數(shù)量。他們還調查了小鼠大腦血流暫時中斷的時候腦基因的表達如何改變,。這組作者發(fā)現(xiàn)在血流終止之后,，586個基因的表達水平更高。這組作者說,，但是當干細胞注射進大腦后,，不到10%的基因表達上調，這提示這些基因很可能參與了炎癥和免疫應答,。相關論文發(fā)表在美國《國家科學院院刊》（PNAS）上,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS，doi: 10.1073/pnas.0803670105,，Hirokazu Ohtaki,，Darwin J. Prockop
Stem/progenitor cells from bone marrow decrease neuronal death in global ischemia by modulation of inflammatory/immune responses
Hirokazu Ohtaki, Joni H. Ylostalo, Jessica E. Foraker, Andrew P. Robinson, Roxanne L. Reger, Seiji Shioda, and Darwin J. Prockop
Human mesenchymal stromal cells (hMSCs) were injected into the hippocampus of adult mice 1 day after transient global ischemia. The hMSCs both improved neurologic function and markedly decreased neuronal cell death of the hippocampus. Microarray assays indicated that ischemia up-regulated 586 mouse genes. The hMSCs persisted for <7 days, but they down-regulated >10% of the ischemia-induced genes, most of which were involved in inflammatory and immune responses. The hMSCs also up-regulated three mouse genes, including the neuroprotective gene Ym1 that is expressed by activated microglia/macrophages. In addition, the transcriptomes of the hMSC changed with up-regulation of 170 human genes and down-regulation of 54 human genes. Protein assays of the hippocampus demonstrated increased expression in microglia/macrophages of Ym1, the cell survival factor insulin-like growth factor 1, galectin-3, cytokines reflective of a type 2 T cell immune bias, and the major histocompatibility complex II. The observed beneficial effects of hMSCs were largely explained by their modulation of inflammatory and immune responses, apparently by alternative activation of microglia and/or macrophages.
