美國(guó)杜克大學(xué)醫(yī)學(xué)中心科學(xué)家日前通過(guò)實(shí)驗(yàn)確認(rèn),，多效生長(zhǎng)因子可促進(jìn)造血干細(xì)胞擴(kuò)張和再生,。這項(xiàng)成果在再生醫(yī)學(xué)領(lǐng)域具有廣闊應(yīng)用前景,。
有關(guān)論文已發(fā)表在新一期英國(guó)《自然—醫(yī)學(xué)》（Nature Medicine）雜志上,。研究人員在論文中表示,，對(duì)需要干細(xì)胞移植的患者而言,，臍帶血是普遍的造血干細(xì)胞來(lái)源,，但臍帶血中的干細(xì)胞數(shù)量通常比較有限,，因此開(kāi)發(fā)出能快速促進(jìn)臍帶血干細(xì)胞生長(zhǎng)的方法就尤為重要。
研究人員將多效生長(zhǎng)因子注入骨髓生長(zhǎng)因受到輻射而被抑制的實(shí)驗(yàn)鼠體內(nèi),，后者的骨髓干細(xì)胞生長(zhǎng)速度與未注射多效生長(zhǎng)因子的實(shí)驗(yàn)鼠相比提高了10倍,。在實(shí)驗(yàn)室培養(yǎng)皿中,，多效生長(zhǎng)因子還被確認(rèn)可促進(jìn)人類(lèi)臍帶血干細(xì)胞的生長(zhǎng)。研究人員還證實(shí),，多效生長(zhǎng)因子不會(huì)導(dǎo)致實(shí)驗(yàn)鼠出現(xiàn)癌變,。
研究人員說(shuō)，這項(xiàng)成果將來(lái)有望使更廣泛的人群受益于臍帶血移植,，更重要的是,，對(duì)正在接受化療或放療的患者而言，利用多效生長(zhǎng)因子進(jìn)行的治療或許具有加速患者血液和免疫系統(tǒng)恢復(fù)的潛力,。不過(guò)他們也表示,，在利用這項(xiàng)成果進(jìn)行臨床治療前，還需要進(jìn)行更多動(dòng)物實(shí)驗(yàn),。
研究人員目前正在進(jìn)一步開(kāi)展實(shí)驗(yàn),，以驗(yàn)證多效生長(zhǎng)因子是否也對(duì)普通干細(xì)胞的生長(zhǎng)和發(fā)展至關(guān)重要。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature Medicine DOI: doi:10.1038/nm.2119
Pleiotrophin regulates the expansion and regeneration of hematopoietic stem cells
Heather A Himburg,Garrett G Muramoto,Pamela Daher,Sarah K Meadows,J Lauren Russell,Phuong Doan,Jen-Tsan Chi,Alice B Salter,William E Lento,Tannishtha Reya,Nelson J Chao& John P Chute
Hematopoietic stem cell (HSC) self-renewal is regulated by both intrinsic and extrinsic signals. Although some of the pathways that regulate HSC self-renewal have been uncovered, it remains largely unknown whether these pathways can be triggered by deliverable growth factors to induce HSC growth or regeneration. Here we show that pleiotrophin, a neurite outgrowth factor with no known function in hematopoiesis, efficiently promotes HSC expansion in vitro and HSC regeneration in vivo. Treatment of mouse bone marrow HSCs with pleiotrophin caused a marked increase in long-term repopulating HSC numbers in culture, as measured in competitive repopulating assays. Treatment of human cord blood CD34+CDCD38?Lin? cells with pleiotrophin also substantially increased severe combined immunodeficient (SCID)-repopulating cell counts in culture, compared to input and cytokine-treated cultures. Systemic administration of pleiotrophin to irradiated mice caused a pronounced expansion of bone marrow stem and progenitor cells in vivo, indicating that pleiotrophin is a regenerative growth factor for HSCs. Mechanistically, pleiotrophin activated phosphoinositide 3-kinase (PI3K) signaling in HSCs; antagonism of PI3K or Notch signaling inhibited pleiotrophin-mediated expansion of HSCs in culture. We identify the secreted growth factor pleiotrophin as a new regulator of both HSC expansion and regeneration.
