两篇Nature涉及干细胞治疗为眼部疾病者带来光明
2016/03/11
Nature最新在线报导的两篇文章都涉及了干细胞与眼睛治疗的研究,令人鼓舞的正面结果将为眼部疾病的人带来光明。


Nature最新在线报导的两篇文章都涉及了干细胞与眼睛治疗的研究,令人鼓舞的正面结果将为眼部疾病的人带来光明。

从人类干细胞生长的多种眼睛组织制成的盘状结构,已经被用来恢复兔子的视力。3月9日Nature的在线报导的一篇文章表明诱导多功能干细胞(iPS)可能有一天被用来为人类的眼睛提供更换角膜或晶状体组织。这些盘状结构还可以用来眼睛组织和先天性眼部疾病的发展。

在同一天Nature在线发表的另一篇文章描绘了一种外科手术,在眼睛有白内障的婴儿中激活人体自身干细胞再生功能产生明晰的、有功能的晶状体。

视觉损失实验中干细胞通过安全检测

在第一项研究中,由在日本大阪大学医学院的眼科医生Kohji Nishida领导的研究小组,培养人的iPS细胞生产包含几种不同类型眼组织的盘状结构。

这些细胞在不同区域生长,因此研究人员可以提取和纯化特定的类型,包括角膜、视网膜和晶状体中的组织。Nishida的团队能够将盘状结构的某个区域的细胞移动到角膜上皮,这样研究人员能成功地将它们移植到有缺陷的兔角膜。

以前的研究已经使用iPS细胞生成的视网膜或角膜组织,但没有在一次实验中产生的不同类型眼部细胞。而且来自受体自身的细胞不会被免疫系统所排斥。

治疗白内障

另一篇文章对治疗白内障几乎是立竿见影的效果,它所描述的技术不包括体外培养细胞或移植材料,这些需要监管部门的批准。新的方法仅仅是手术过程中的变化,不是人工晶状体,只是让晶状体再生。

这一研究受到了人工晶状体植入术治疗白内障的典型副作用的影响:由于受体自身细胞的生长,新的晶状体往往变得浑浊。由加利福尼亚圣地亚哥分校的眼科学家张康和广州中山大学的刘奕志决定找出这种再生长是否是意味着能够再生整个晶状体。

研究人员开始了一系列的动物实验,来评估晶状体上皮干/祖细胞(LEC)是否存在于一个完全形成哺乳动物的眼睛,可以产生一个新的晶状体。让人鼓舞的结果是团队开发出了一种外科技术,先实施在兔、猴身上,最后是12个人类的婴儿。

下一步

对于儿童白内障标准的手术治疗是在晶状体囊中央切割6毫米的缝,这种切口让外科医生可以移除患者患病的晶状体,用人造的来取代,但也导致损伤了很多LEC。

在新的方法中,外科医生在晶状体囊一侧切割1.5毫米的切口移除病变的晶状体,促使眼睛的LEC生长出一个新的。在最初的测试中,这种方法产生的并发症只有17%,比典型的白内障手术92%要低得多。而所产生的晶状体并没有像人工晶状体那样变得不透明。

张康说第一个婴儿两年前用该方法进行手术,现在仍有良好的视力。他介绍再生的晶状体会随着孩子的生长而生长,可以减少并发症的发生。

不过仍然有困难有待解决,患有白内障的婴儿通常有基因突变会导致新的晶状体浑浊。而单纯的手术可能不适合老年人——最有可能患白内障的人,因为他们的细胞再生相对缓慢。(即使是在用这种方法治疗的婴儿中,一个新的晶状体的生长也需要三个月的时间)。

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