新眼角膜(cornea)移植可能是阻止病人眼睛變瞎的唯一方法,，但是捐獻(xiàn)的角膜存在短缺，因而排隊(duì)等待角膜移植的隊(duì)伍比較長,。來自瑞典哥德堡大學(xué)薩爾格學(xué)院(Sahlgrenska Academy)的科學(xué)家第一次成功地在人角膜上培養(yǎng)干細(xì)胞,，并且長期而言，這可能導(dǎo)致人們不再需要捐獻(xiàn)者捐獻(xiàn)角膜,。
在瑞典,，每年需要進(jìn)行大約500例角膜移植手術(shù)，而在全世界則這一數(shù)字大約是10萬,。角膜受損和變得渾濁將讓病人變瞎,，但是它能夠被一個(gè)健康和透明的角膜替換。但是這種過程需要一個(gè)捐獻(xiàn)的角膜,，只是捐獻(xiàn)的角膜嚴(yán)重短缺,。在全世界，這種情形也是如此,，尤其是一些宗教或政治觀點(diǎn)經(jīng)常阻礙人們使用捐獻(xiàn)的角膜的地方,。
替換捐獻(xiàn)的眼角膜
來自薩爾格學(xué)院的科學(xué)家朝利用干細(xì)胞培育的眼角膜替換捐獻(xiàn)的眼角膜的最終目標(biāo)邁出了第一步?？茖W(xué)家Charles Hanson和Ulf Stenev所i使用的缺陷性眼角膜是從默恩達(dá)爾市薩格林斯卡大學(xué)附屬醫(yī)院(Sahlgrenska University Hospital in Mölndal)眼科門診獲得的,。他們的研究結(jié)果發(fā)表Acta Ophthalmologica在期刊上，而且表明他們先在實(shí)驗(yàn)室培養(yǎng)16天接著在角膜上培養(yǎng)6天后能夠讓人干細(xì)胞變成“上皮細(xì)胞(epithelial cell)”,。而正是上皮細(xì)胞維持眼角膜的透明。
第一次在人角膜上培養(yǎng)干細(xì)胞
“類似的實(shí)驗(yàn)在動(dòng)物上進(jìn)行過,，但是這是第一次讓干細(xì)胞在人受損角膜上生長,。它意味著我們朝能夠使用干細(xì)胞治療受損角膜的最終目標(biāo)邁出了第一步”，Charles Hanson說,。“如果我們能夠?yàn)榇私⒁环N常規(guī)的方法,，那么就可以給需要角膜的病人提供無窮無盡的新角膜。移植手術(shù)程序和術(shù)后護(hù)理也將變得更加簡單”,，Ulf Stenevi說,。
只有少數(shù)診所能夠進(jìn)行角膜移植
當(dāng)前只有一些診所能夠開展角膜移植手術(shù),。在瑞典，很多角膜移植手術(shù)是在薩格林斯卡大學(xué)附屬醫(yī)院眼科門診完成的,。(生物谷：towersimper編譯)
doi:10.1111/j.1755-3768.2011.02358.x
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Transplantation of human embryonic stem cells onto a partially wounded human cornea in vitro
Charles Hanson, Thorir Hardarson, Catharina Ellerström, Markus Nordberg, Gunilla Caisander, Mahendra Rao, Johan Hyllner, Ulf Stenevi
Purpose: The aim of this study was to investigate whether cells originating from human embryonic stem cells (hESCs) could be successfully transplanted onto a partially wounded human cornea. A second aim was to study the ability of the transplanted cells to differentiate into corneal epithelial-like cells.
Methods: Spontaneously, differentiated hESCs were transplanted onto a human corneal button (without limbus) with the epithelial layer partially removed. The cells were cultured on Bowman’s membrane for up to 9 days, and the culture dynamics documented in a time-lapse system. As the transplanted cells originated from a genetically engineered hESC line, they all expressed green fluorescent protein, which facilitated their identification during the culture experiments, tissue preparation and analysis. To detect any differentiation into human corneal epithelial-like cells, we analysed the transplanted cells by immunohistochemistry using antibodies specific for CK3, CK15 and PAX6.
Results: The transplanted cells established and expanded on Bowman’s membrane, forming a 1–4 cell layer surrounded by host corneal epithelial cells. Expression of the corneal marker PAX6 appeared 3 days after transplantation, and after 6 days, the cells were expressing both PAX6 and CK3.
Conclusion: This shows that it is possible to transplant cells originating from hESCs onto Bowman’s membrane with the epithelial layer partially removed and to get these cells to establish, grow and differentiate into corneal epithelial-like cells in vitro.
