The Media is the Message: How Stem Cells Grow Depends On What They Grow Up In

hyde

培养条件决定干细胞的状态
! `+ i3 ^4 y. [" w4 Khttps://health.ucsd.edu/news/rel ... em-cell-growth.aspx0 I+ y. i; `5 R
人多能干细胞是研究人类早期发育和疾病发生的一个功能强大的工具，因为它们几乎可以形成人体内的各种组织细胞。但这些能力依赖于它们的培养条件。Scientific Reports在5月4号网上发表了一篇文章，作者是来自at University of California, San Diego School of Medicine，他们使用一种叫做 “design of experiments” （DOE）的统计学工具优化出适合人多能干细胞生长的培养条件。
- ~; m* q4 s8 o. nAlysson Muotri, PhD, associate professor in the UC San Diego departments of Pediatrics and Cellular and Molecular Medicine 说：“目前，在全球各地的不同实验室，他们培养干细胞的方法和培养基千差万别，有些培养条件的化学成分还没有被研究清楚。各个批次间培养基存在很多因素的差异，它们会影响干细胞的生长。这会给科学研究带来很大的影响。比如，研究进展缓慢，因为系统的不稳定。同时不同的培养基也会导致其他实验室无法重复验证实验数据。”
3 R8 A4 e6 t3 U6 C2 b0 a1 ?8 f! Z- [Muotri和他的团队使用DOE检测hPSC培养基中的两个关键生长因子，bFGF和NRG-1 beta 1. DOE经常被使用在科学仪器中检测数据中的差异，但是在生物学中的使用还比较少。8 L) ^. {4 P$ k" d  V9 G
Muotri 说“当你问一个生物专业的学生一个酶的最适合温度和pH,这个学生可能会使用两个独立的实验去检测这些数值，然后他们会得到一个错误的结论。他们缺少的是环节是考虑这两个参数的相关性。DOE分析时会考虑多因子之间的相关性，是正相关，负相关还是不相关”。- m: E9 x' D1 I8 n3 w

  y2 e% q# i* m, ~他们的前期工作分析了hPSC培养基中的上百个成分，基于这些工作，他们确定了hPSC培养基中bFGF和NRG-1 beta 1成分的最佳含量。当然，他们也指出他们的结果并不是固定的不变的，如果研究发现影响hPSC的新成分，他们可以将它们加入到DOE矩阵模型中进行重新分析，确定新的配方。/ b( j$ Y5 E. |4 }& C9 j
研究者希望他们的研究结果能够给干细胞培养提供一个新的标准，“世界上的任何一个实验室可以使用相同培养配方的培养条件研究干细胞，这可以应用于对hPSC的分化研究。我们希望选择出一种过渡培养基，模拟人类胚胎的环境（？）。”
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Human pluripotent stem cells (hPSCs) possess the ability to grow into almost any kind of cell, which has made them dynamic tools for studying early human development and disease, but much depends upon what they grow up in.6 i/ |* b8 [* z; y5 N$ U: O& w
Writing in the May 4 online issue of the journal Scientific Reports, researchers at University of California, San Diego School of Medicine used a powerful statistical tool called “design of experiments” or DOE to determine the optimal cell culture formula to grow and produce hPSCs.6 }# R9 i/ D# F% Z% O
cultured stem cells* Z# e6 L; M  ?5 j* V/ @
Colonies of human embryonic stem cells seen with a fluorescent microscope. Image courtesy of California Institute for Regenerative Medicine.7 P2 S0 Z/ B) m0 `6 }2 w
“Currently, there are different culture methods and media that are not optimized or even chemically defined. There are several factors that may affect the growth of stem cells based on batch-to-batch media variation,” said Alysson Muotri, PhD, associate professor in the UC San Diego departments of Pediatrics and Cellular and Molecular Medicine. “This affects science in many ways. For example, it slows down progress because conditions may not be pristine. It also makes it difficult for other labs to validate data because the media they use will likely not be the same as in the original experiments.”1 d4 g) ?0 z* y
Muotri and colleagues used DOE to measure two critical growth factors used in hPSC media: basic fibroblast growth factor (bFGF) and neuregulin-1 beta 1 (NRG-1 beta 1).  DOE is often used in scientific endeavors to measure and account for variations in data, but not so much in biology, said Muotri.  " A# Z" b' k2 y( B4 p7 q
“If you ask a biology student what is the ideal temperature and pH for an enzyme, he/she will try to determine the best temperature in one experiment and the best pH in another experiment. Then, the student will erroneously conclude that these represent the optimal temperature and pH,” said Muotri. “What is missing is the interaction between temperature and pH. The best working temperature may not be the most optimal pH condition. DOE takes into account positive, negative or neutral interactions between multiple factors at the same time.”6 G: _2 n' Q% A
Building upon earlier work, which had analyzed hundreds of other factors in hPSC media, the researchers determined the best formulations for bFGF and NRG-1 beta 1. They noted, however, that their findings are not fixed. “If science discovers a new factor that affects hPSC proliferation, we can add it into our DOE matrix to quickly test and re-formulate the media,” said Muotri.* S, p( f. r7 J
The researchers hope their findings will lead to a new standard for hPSC cultures. “Any lab in the world can have access to the same formulation, with no variability,” said Muotri. “We also think this method could be applied towards the development of culture conditions during differentiation of human stem cells. Ideally, we want to create transition media formulations that subtly change during cell type specialization, mimicking the human embryo.”
: u( F6 [1 w# Q- V5 O$ \: CMuotri said his team is working with the UC San Diego Technology Transfer Office to find industry partners to assist in making the new technology accessible to all laboratories using hPSCs.
2 A" Z1 ]: s& T- tCo-authors include Paulo A. Marinho and Thanathom Chailangkarn, UCSD Department of Pediatrics/Rady Children’s Hospital-San Diego, Department of Cellular and Molecular Medicine and UCSD Stem Cell Program.7 w6 ^! l3 ^$ c: P7 v& R8 e! U
Funding for this research came, in part, from the California Institute for Regenerative Medicine and the National Institutes of Health (1-DP2-OD006495-1).

watchen198891

都没人来关注，我来学习一下。两年多的干细胞培养，我认为这篇文章的观点非常正确，在干细胞培养过程中，不是单一的因素影响干细胞状态，是很多个环节影响，对于关键生长因子方面也的确是这样，相关因子之间存在着可能的联系，这些联系也会对干细胞的状态带来一定的影响，包括配置干细胞培养基的时候添加因子的顺序，有可能因为PH的变化会造成某些因子在配置的过程中就已经失活或者功效缺失。我认为干细胞培养基的配置不仅仅是单一关键因子来决定，而是像文章所说尽量模仿干细胞在体内生长的环境，让这个干细胞的培养体系成为干细胞生长的过渡环境，了解多个因子之间的相互联系，怎样使培养体系稳定，配置时生长因子添加的顺序，这样才能完善体外的干细胞培养体系。