PNAS:独特的双功能干细胞
生物通/叶予 · 2014/11/25
成体干细胞是机体内的器官维持和组织再生的基础。南加州大学的Krzysztof Kobielak领导研究团队,在指甲底部的软组织中发现了一种新型干细胞。这些细胞被称为双功能干细胞,它们除了自我更新,还拥有形成指甲或上皮组织的双重能力。


与某些两栖类动物相比,哺乳动物的再生能力比较差。人类机体有许多部件是失去了就回不来的,但毛囊、汗腺、指甲这些皮肤附件例外。南加州大学的科学家们揭示了这其中的原因,他们的这项研究发表在美国国家科学院院刊PNAS杂志上。

成体干细胞是机体内的器官维持和组织再生的基础。南加州大学的Krzysztof Kobielak领导研究团队,在指甲底部的软组织中发现了一种新型干细胞。这些细胞被称为双功能干细胞,它们除了自我更新,还拥有形成指甲或上皮组织的双重能力。

研究人员将荧光蛋白和其他可视化“标签”贴在小鼠的指甲细胞上,建立了一个标记滞留细胞鉴定系统(LRC)。他们发现,系统中大多数细胞反复分裂,它们的后代逐渐增多,冲淡了原有的荧光和标记。不过,在近端甲皱襞(nail proximal fold)的基底层,有一些细胞始终保持着强荧光和标记。这些围绕在指甲根部的细胞基本不分裂或者分裂的很慢,表现出了干细胞的独特性质。

研究显示,这些新发现的干细胞很灵活,能够起到双重作用。在正常情况下,它们负责指甲和附近皮肤的生长,而且更倾向于后者。然而一旦指甲受伤或者缺失,这些干细胞就会转变职能,专门对指甲进行修复。研究人员还通过转录谱分析发现,促使双功能干细胞修复指甲的信号来自于骨形态发生蛋白(BMP)。

下一步,研究人员希望通过合适的信号,诱导双功能干细胞再生出其他类型的组织。这样的研究将帮助人们修复指甲和指头的缺陷、治疗严重的皮肤损伤甚至进行断指再生。

“这些干细胞能在特定生理条件下再生指甲和皮肤,这是一个令人惊讶的发现。它们的双重性质非常独特,有别于其他皮肤干细胞,比如毛囊或汗腺的干细胞,”Kobielak说。

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