據(jù)英國《獨(dú)立報》1月12日報道，美國研究人員表示,，實(shí)驗(yàn)首次證明,，使用人類胚胎干細(xì)胞研制出的血小板可修復(fù)實(shí)驗(yàn)鼠的受損組織，人類未來有望源源不斷地制造出起作用的血小板,，捐血有可能成為歷史。
血小板是哺乳動物血液中的有形成分之一,。血小板在止血,、傷口愈合、炎癥反應(yīng),、血栓形成及器官移植排斥等生理和病理過程中有重要作用,，接受癌癥治療或器官移植手術(shù)的病人常需要血小板來修復(fù)受損的身體組織和血管及預(yù)防無法控制的大出血。沒有血小板,，醫(yī)生將無法快速而準(zhǔn)確地治愈病人受損的身體組織,，病人也可能因?yàn)閮?nèi)出血而死亡。
醫(yī)生一般從捐贈的血液中提取血小板,，然而,，血小板不能被冷凍且只能存放7天到10天，如果用血量大,，醫(yī)院常會出現(xiàn)血小板不足的情況,，因此，科學(xué)家一直在尋找能源源不斷制造出血小板的方法,，讓人們不再需要輸血,。
美國先進(jìn)細(xì)胞技術(shù)公司的科學(xué)家使用從多余的試管嬰兒胚胎中提取出的干細(xì)胞制造出了血小板?？茖W(xué)家先將這些干細(xì)胞轉(zhuǎn)變成特殊的巨核細(xì)胞,，接著在實(shí)驗(yàn)室中對其進(jìn)行培養(yǎng),，最終得到了完全成熟的血小板。研究證明,，在將其注入實(shí)驗(yàn)鼠體內(nèi)時,，這些血小板能修復(fù)老鼠受損的身體組織，就像它們在人體內(nèi)所做的一樣,。
該公司首席科學(xué)家,、人類胚胎干細(xì)胞克隆先驅(qū)羅伯特·蘭扎表示，他們研制出的血小板在外觀和工作方式上與捐贈血液中提取出來的血小板一樣,，也能被血液中天然存在的凝血劑凝血酶所激活,。蘭扎說：“令人驚奇的是，這些血小板甚至是雙凹面的圓盤形,，而且,，在活的實(shí)驗(yàn)鼠中，這些血小板可吸收凝血酶,，就像真的血小板一樣,。科學(xué)家可采用這種方法制造出能無限供應(yīng),、起作用的血小板,。”
此外，研究人員還認(rèn)為,，用這種方式制造出的血小板并不包含任何遺傳物質(zhì),，這消除了癌癥腫瘤可能進(jìn)入受體體內(nèi)的風(fēng)險，因而不會給病人的健康帶來危害,，可以在臨床治療中大展拳腳,。（生物谷Bioon.com）
生物谷推薦原文出處：
Cell Research doi:10.1038/cr.2011.8.
Platelets generated from human embryonic stem cells are functional in vitro and in the microcirculation of living mice.
Lu SJ, Li F, Yin H, Feng Q, Kimbrel EA, Hahm E, Thon JN, Wang W, Italiano JE, Cho J, Lanza R.
[1] Stem Cell and Regenerative Medicine International, 33 Locke Drive, Marlborough, MA 01752, USA [2] Department of Applied Bioscience, Cha University, Seoul, Korea.
Abstract
Platelets play an essential role in hemostasis and atherothrombosis. Owing to their short storage time, there is constant demand for this life-saving blood component. In this study, we report that it is feasible to generate functional megakaryocytes and platelets from human embryonic stem cells (hESCs) on a large scale. Differential-interference contrast and electron microscopy analyses showed that ultrastructural and morphological features of hESC-derived platelets were indistinguishable from those of normal blood platelets. In functional assays, hESC-derived platelets responded to thrombin stimulation, formed microaggregates, and facilitated clot formation/retraction in vitro. Live cell microscopy demonstrated that hESC-platelets formed lamellipodia and filopodia in response to thrombin activation, and tethered to each other as observed in normal blood. Using real-time intravital imaging with high-speed video microscopy, we have also shown that hESC-derived platelets contribute to developing thrombi at sites of laser-induced vascular injury in mice, providing the first evidence for in vivo functionality of hESC-derived platelets. These results represent an important step toward generating an unlimited supply of platelets for transfusion. Since platelets contain no genetic material, they are ideal candidates for early clinical translation involving human pluripotent stem cells.
