（圖片來(lái)源：Proceedings of the National Academy of Sciences）
哈佛醫(yī)學(xué)院的研究人員對(duì)幼鼠斷指（趾）再生進(jìn)行了研究，發(fā)現(xiàn)引起再生的細(xì)胞為譜系限制性祖細(xì)胞,，而非多能干細(xì)胞,，或許有利于揭示斷指再生的機(jī)制。其研究結(jié)果近日發(fā)表在《美國(guó)國(guó)家科學(xué)院院刊》（Proceedings of the National Academy of Sciences）上。
有研究表明,，幼兒和鼠具有再生指（趾）的能力,，但僅限于甲床區(qū)，因該區(qū)域Msx1 基因表達(dá)水平較高,。當(dāng)發(fā)生斷指（趾）時(shí),，胚芽處的大量快速分裂細(xì)胞分裂，產(chǎn)生斷指（趾）再生,。
Jessica Lehoczky等對(duì)胚芽細(xì)胞了研究,，以了解其是否屬于多能干細(xì)胞或異質(zhì)性祖細(xì)胞。
研究者使用組織特異性基因標(biāo)記研究幼鼠再生趾的起始細(xì)胞,，發(fā)現(xiàn)該再生趾起源于斷趾處的譜系限制性祖細(xì)胞,，而不是多能干細(xì)胞。此外,，對(duì)Msx1基因的研究發(fā)現(xiàn),，Msx1高表達(dá)細(xì)胞并非多能干細(xì)胞，但或許與細(xì)胞信號(hào)轉(zhuǎn)導(dǎo)有關(guān),。
該研究表明創(chuàng)傷愈合和再生的過(guò)程或較之前的研究結(jié)果更為完整,，更為獨(dú)立，也解釋了人類以及鼠的再生能力隨著年齡增長(zhǎng)而下降的原因,。（生物谷bioon.com）
doi:10.1016/10.1073/pnas.1118017108
PMC:
PMID:
Mouse digit tip regeneration is mediated by fate-restricted progenitor cells
Jessica A. Lehoczky, Beno?t Robert, and Clifford J. Tabin.
Regeneration of appendages is frequent among invertebrates as well as some vertebrates. However, in mammals this has been largely relegated to digit tip regeneration, as found in mice and humans. The regenerated structures are formed from a mound of undifferentiated cells called a blastema, found just below the site of amputation. The blastema ultimately gives rise to all of the tissues in the regenerate, excluding the epidermis, and has classically been thought of as a homogenous pool of pluripotent stem cells derived by dedifferentiation of stump tissue, although this has never been directly tested in the context of mammalian digit tip regeneration. Successful digit tip regeneration requires that the level of amputation be within the nail bed and depends on expression of Msx1. Because Msx1 is strongly expressed in the nail bed mesenchyme, it has been proposed that the Msx1-expressing cells represent a pluripotent cell population for the regenerating digit. In this report, we show that Msx1 is dynamically expressed during digit tip regeneration, and it does not mark a pluripotent stem cell population. Moreover, we show that both the ectoderm and mesoderm contain fate-restricted progenitor populations that work in concert to regenerate their own lineages within the digit tip, supporting the hypothesis that the blastema is a heterogeneous pool of progenitor cells.
