It turns out urine isn’t just human waste. Chinese researchers have managed to reprogram kidney cells harvested from urine samples into neural cell progenitors–immature brain cells that can develop into various types of glial cells and neurons. Reprogramming cells has been done before, of course, but not with cells gleaned from urine and not via a method this direct (more on that in a moment). The technique could prove extremely helpful to those pursuing treatments for neurodegenerative disorders like Parkinson’s and Alzheimer’s.
原来尿液不仅仅是人类的排泄物。中国研究人员已经成功地从尿液样本中提取的肾细胞重新编程为神经细胞祖细胞——不成熟的脑细胞，可以发育成各种类型的胶质细胞和神经元。当然，细胞的重新编程以前就已经做过了，但不是用从尿液中收集的细胞，也不是通过这种直接的方法（稍后会详细介绍）。这项技术对那些寻求帕金森氏症和阿尔茨海默氏症等神经退行性疾病治疗的人可能非常有帮助。
The innovation here is in the source and the method. We know that embryonic stem cells offer potential treatments for neurodegenerative disorders. And we know that we can turn adult human cells–that is, non-embryonic cells gathered from adult humans–into pluripotent cells (those that can become a different type of cell) by reprogramming them, usually with genetically engineered viruses that tamper with the cells’ genetic codes.
本文的创新之处在于来源和方法。我们知道胚胎干细胞为神经退行性疾病提供了潜在的治疗方法。我们知道，我们可以通过重新编程将成人细胞——也就是从成人身上收集的非胚胎细胞——转化为多能干细胞（那些可以成为不同类型细胞的细胞），通常是用基因工程病毒篡改细胞的基因密码。
But embryonic stem cell treatments are fraught with ethical issues and non-embryonic methods are complicated–and complexity introduces a greater chance of something going wrong (in this case that means mutations and genetic defects). The new method, which taps skin-like cells from the linings of the kidney tubes that are present in urine, converts its source cells into neurons and glia cells via a more direct route, making the process more efficient while narrowing the margin of error.
但是胚胎干细胞治疗充满了伦理问题，非胚胎方法也很复杂，而且复杂性会增加出错的可能性（在这种情况下，意味着突变和基因缺陷）。这种新方法从尿液中存在的肾小管里中提取皮肤样细胞，通过更直接的途径将其来源细胞转化为神经元和胶质细胞，使这一过程更有效，同时缩小了误差范围。
In their study, the researchers harvested kidney cells from the urine samples of three human donors and converted the cells directly to neural progenitors. Rather than using a genetically engineered virus to reprogram the cells, they used a small piece of bacterial DNA that can replicate in the cellular cytoplasm, a technique that eliminates the need to tamper directly with the chromosome (in theory, at least, this should reduce mutations) while also speeding up the entire process. After growing their progenitors into mature neurons and glial cells, the researchers transplanted the progenitors into the brains of newborn rats. A month later, the cells were still alive in the rats’ brains, though it is not yet clear that they can survive for extended periods or mesh with the brain’s wiring to become functioning parts of the neural machine.
在他们的研究中，研究人员从三个人类捐赠者的尿液样本中获取肾细胞，并将这些细胞直接转化为神经祖细胞。他们没有使用基因工程病毒对细胞进行重新编程，而是使用了一小块可以在细胞质中复制的细菌DNA，这种技术消除了直接篡改染色体的需要（至少在理论上，这应该可以减少突变），同时也加快了整个过程。在将它们的祖细胞培养成成熟的神经元和胶质细胞后，研究人员将这些祖细胞移植到新生大鼠的大脑中。一个月后，这些细胞仍然在老鼠的大脑中存活，尽管目前还不清楚它们是否能存活很长时间，或者是否能与大脑的连线相结合，成为神经机器的功能部分。
There’s still a lot of research to be done on this method of course, but the researchers think it may provide a way to take cells gathered non-invasively and quickly and efficiently convert them into neural cells while reducing the likelihood of genetic mutations.
当然，这种方法还有很多研究要做，但研究人员认为，它可能提供了一种方法，使收集的细胞非侵入性地、快速有效地转化为神经细胞，同时降低基因突变的可能性。