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世界性命科学前沿动态周报（八十五）
干细胞步骤医治失明成功能于老鼠
科技日报Science Daily 2013年1月7日：牛津大学纳菲尔德临床神经科学系的教授Robert MacLaren和新加坡国立大学医院的眼科医生Mandeep Singh钻研发现，将发育中的细胞移植入失明老鼠的眼睛后，可能沉建其视网膜的整个光敏层 。〖国国度科学院院刊》在线颁发了他们的有关钻研了局 。
钻研人员称这个步骤能够援手医治色生性视网膜炎患者，这类患者因视网膜的光敏细胞逐步殒命导致渐进性失明 。他们用最近似的失明老鼠模型做尝试，两周后发现将发育细胞移植入眼后在视网膜上沉建了整个光敏层，且老鼠能够看见器材了 。他们使用的是老鼠发育中的视网膜细胞初期的前体细胞 。瞳孔收缩尝试发现12只老鼠中有10只老鼠对光的瞳孔收缩反映提高，批注老鼠的视网膜再次有了光感，且经视神经盘传至了大脑 。
Dr. Singh说，“我们发现若是将足够数量的细胞移植在一路，不仅能产生光敏性，并且还能再生出产生视力所需的衔接 。MacLaren称他们想使用iPSCs来进行钻研，但愿能够实现细胞疗法医治人类失明 。这些来自患者体内的细胞如皮肤或血液细胞产生的干细胞能够直接形成视网膜细胞的前体细胞 。他还称这是前人实现的了局，将来在患者上的利用如同探囊取物 。下一步的指标是在病人体内找到靠得住的细胞起源以便提供细胞移植所需的干细胞 。
点评: 用iPSCs来进行色生性视网膜炎钻研目前只是实现了此类老鼠再次获得光感，但若何解决再生出产生视力所需的衔接仍是重要的难题 。
有关文件：
Reversal of end-stage retinal degeneration and restoration of visual function by transplantation
Author: Mandeep S. Singha, Peter Charbel Issaa, Rachel Butlera, Chris Martinb, Daniel M. Lipinskia, Sumathi Sekarana, Alun R. Barnarda, and Robert E. MacLarena,c,d,1
Edited by Constance L. Cepko, Harvard Medical School and Howard Hughes Medical Institute, Boston, MA, and approved December 7, 2012 (received for review November 24, 2011)
Abstract
One strategy to restore vision in retinitis pigmentosa and age-related macular degeneration is cell replacement. Typically, patients lose vision when the outer retinal photoreceptor layer is lost, and so the therapeutic goal would be to restore vision at this stage of disease. It is not currently known if a degenerate retina lacking the outer nuclear layer of photoreceptor cells would allow the survival, maturation, and reconnection of replacement photoreceptors, as prior studies used hosts with a preexisting outer nuclear layer at the time of treatment. Here, using a murine model of severe human retinitis pigmentosa at a stage when no host rod cells remain, we show that transplanted rod precursors can reform an anatomically distinct and appropriately polarized outer nuclear layer. A trilaminar organization was returned to rd1 hosts that had only two retinal layers before treatment. The newly introduced precursors were able to resume their developmental program in the degenerate host niche to become mature rods with light-sensitive outer segments, reconnecting with host neurons downstream. Visual function, assayed in the same animals before and after transplantation, was restored in animals with zero rod function at baseline. These observations suggest that a cell therapy approach may reconstitute a light-sensitive cell layer de novo and hence repair a structurally damaged visual circuit. Rather than placing discrete photoreceptors among preexisting host outer retinal cells, total photoreceptor layer reconstruction may provide a clinically relevant model to investigate cell-based strategies for retinal repair.
http://www.pnas.org/content/early/2013/01/02/1119416110.full.pdf+html?sid=34885f40-f132-424c-8fd7-610f740be4f3