精原干細(xì)胞(SSCs)是干細(xì)胞臨床應(yīng)用的理想材料,，通過研究發(fā)現(xiàn),，精原干細(xì)胞在體外培養(yǎng)過程中會(huì)有一部分細(xì)胞自主變成類似胚胎干細(xì)胞的一種細(xì)胞。但是自主轉(zhuǎn)化的時(shí)間周期較長(zhǎng),，通常需要幾個(gè)月時(shí)間,，而且轉(zhuǎn)化率非常低，通過病毒載體轉(zhuǎn)染后雖然增加了轉(zhuǎn)化效率但是引入外源基因會(huì)造成臨床應(yīng)用潛在危險(xiǎn),。伊利諾伊大學(xué)研究人員最近研究發(fā)現(xiàn)精原干細(xì)胞可通過誘導(dǎo)直接轉(zhuǎn)化成各種終端細(xì)胞,，轉(zhuǎn)化過程中不需要添加外源基因。
在最新研究中,，研究人員巧妙運(yùn)用上皮組織細(xì)胞和細(xì)胞間質(zhì)誘導(dǎo)精原干細(xì)胞成為各種終端細(xì)胞,。上皮組織中存在很多腺體，可分泌大量酶和激素及其他細(xì)胞生長(zhǎng)因子,。20世紀(jì)50年代科學(xué)家就已經(jīng)發(fā)現(xiàn)上皮組織對(duì)其所在器官的細(xì)胞生長(zhǎng)分化起到巨大作用,，上皮細(xì)胞通過分泌行為可誘導(dǎo)細(xì)胞分化成不同形態(tài)和功能的終端細(xì)胞,。
伊利諾伊大學(xué)研究人員將精原干細(xì)胞與前列腺上皮組織細(xì)胞混合移植到小鼠體內(nèi)時(shí)，精原干細(xì)胞轉(zhuǎn)化為前列腺細(xì)胞,；當(dāng)精原干細(xì)胞與皮膚上皮組織細(xì)胞混合移植到小鼠體內(nèi)時(shí),，精原干細(xì)胞轉(zhuǎn)化為皮膚細(xì)胞；將精原干細(xì)胞與子宮上皮細(xì)胞混合移植到小鼠體內(nèi)時(shí),，精原干細(xì)胞也轉(zhuǎn)化成子宮細(xì)胞,。通過用熒光蛋白標(biāo)記表明轉(zhuǎn)化為各種終端細(xì)胞的的確為精原干細(xì)胞。
研究人員表示這項(xiàng)技術(shù)有望代替胚胎干細(xì)胞廣泛應(yīng)用于臨床及再生醫(yī)學(xué)領(lǐng)域,，避免了胚胎干細(xì)胞來源和倫理問題及iPS細(xì)胞的安全性問題,。（生物谷Bioon.com）
生物谷推薦原始出處：
Stem Cells Vol. 27 No. 7 July 2009, pp. 1666 -1675 doi:10.1002/stem.93
Direct Transdifferentiation of Stem/Progenitor Spermatogonia Into Reproductive and Nonreproductive Tissues of All Germ Layers
Liz Simona, Gail C. Ekmana, Natalia Kosterevaa, Zhen Zhanga, Rex A. Hessa, Marie-Claude Hofmanna,b, Paul S. Cookea,c
aDepartment of Veterinary Biosciences,University of Illinois, Urbana, Illinois, USA
bInstitute for Genomic Biology, and University of Illinois, Urbana, Illinois, USA
cDivision of Nutritional Sciences, University of Illinois, Urbana, Illinois, USA
Pluripotent stem cells have great clinical potential for tissue regeneration/repair in humans. The use of embryonic stem (ES) cells is ethically controversial, leading to searches for other sources of pluripotent stem cells. Testicular spermatogonial stem cells (SSCs) produce the spermatogenic lineage. Under in vitro conditions, SSCs have the ability to give rise to pluripotent ES-like cells. We hypothesized that stem/progenitor spermatogonia could directly transdifferentiate into different tissue types if they were recombined with inductive mesenchymes from fetal/neonatal organs using a tissue separation/recombination methodology and grown in vivo. Green fluorescent protein transgenic mice were used to track cell lineages. Our results indicate that stem/progenitor spermatogonia recombined with the appropriate mesenchyme can directly transdifferentiate in vivo into tissues of all germ layers, including prostatic, uterine, and skin epithelium. In addition, transdifferentiated tissue expressed molecular, histological, and functional markers of the appropriate epithelium. The ability of stem/progenitor spermatogonia to directly generate various epithelia emphasizes their clinical potential, and if adult human SSCs have similar properties, this may have applications in human regenerative medicine.
