Name: how embryonic stem cells become specialized
Uploaded: 2019-03-11T09:21:21.000Z
Duration: 58 s
Channel: JoVE

胚性幹細胞、またはES細胞は、3〜5日齢の胚である 胚盤胞の内部細胞塊から 生じる未分化細胞です。多能性であり、血液から脳細胞に至るまで 体内ですべての異なる細胞型を作り出すことができることを 意味しており、それらは科学および医学における 多種多様な潜在的用途を与えます。それらは除去されそして培養中で増殖され、無限に分裂して新しい幹細胞を 産生することができます。例えば、特定の増殖因子を添加することによって 培養条件を操作することで，細胞を特定の細胞型に分化するように 同軸にすることができます。これらの新しい細胞は、1型糖尿病で破壊される膵臓のインスリン産生細胞など、損傷や病気によって失われた体内の細胞を 置き換えるのに使用することができます。

「Concise Review: Human Embryonic Stem Cells—What Have We Done?」私たちは何をしているのか?私たちはどこへ行くのですか?」 STEM CELLS 35, no. 1 (2017): 17–25.[<a href="https://doi.org/10.1002/stem.2450" target="__blank">ソース</a>]

胚性幹細胞

Embryonic Stem Cells

胚性幹細胞（ES細胞）は、未分化な多能性細胞であり、体内のあらゆる種類の細胞を作り出すことができます。そのため、特定の種類の細胞を生成して研究に利用したり、損傷や病気で失われた体細胞を補ったりすることができ、科学や医学の分野で大きな可能性を秘めています。
 
 <h4>起源</h4>
 
 ES細胞は、ヒトでは受精後約3日から5日で子宮に移植される胚盤胞期の胚の内部細胞塊に存在します。ヒトES細胞は、通常、体外受精（IVF）の際に残った受精卵を提供してもらい、それをもとに作られます。
 
 この細胞を集めて培養すると、無限に分裂できるので、ES細胞株ができます。ES細胞は、特定の条件下で、自然にさまざまな種類の細胞に分化したり、希望する種類の細胞に分化したりできます。培養皿の表面を変えたり、培養液に特定の成長因子を加えたりといった培養条件の操作や、細胞の遺伝子組み換えによって、生成される細胞の種類をコントロールできます。これらの方法により、ES細胞から、血液、神経、心臓、骨、肝臓、膵臓など、さまざまな種類の細胞を作り出すことができるようになりました。
 
 <h4>再生医療</h4>
 
 再生医療とは、死んだ組織、病気の組織、機能不全の組織に代わって、生きた機能的な組織を作ることです。ES細胞は、あらゆる種類の細胞に分化できるため、再生医療に用いられます。この分野はまだ初期段階にあるが、ES細胞からいくつかの有用な細胞が作られ、患者に対する安全性と有効性を検証する臨床研究が始まっています。例えば、半身不随の患者さんにES細胞から神経系の細胞を投与したところ、動きが戻ったという結果も出ています。また、ES細胞は、他の方法では困難なヒトの発達の初期段階の研究に使用でき、薬物検査やその他の科学的研究に使用できる特定の種類の細胞の供給源にもなります。

胚性幹細胞(ES)は未分化の多能性細胞であり、体内で任意の種類の細胞を産生できます。これは彼らに途方もない可能性を与えます...

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how embryonic stem cells become specialized

Embryonic stem cells are pluripotent cells that have not yet specialized. Pluripotent means they can give rise to many different cell types in the body. Because of this, they are useful in science and medicine for making cells needed in research or for replacing cells lost to damage or disease.

These cells come from the inner cell mass of a blastocyst, which is an early embryo about 3 to 5 days after fertilization in humans. At this stage, the embryo has not yet implanted in the uterus. Human embryonic stem cells are usually taken from donated embryos left over from in vitro fertilization, or IVF.

Once collected, the cells are grown in culture and can divide for a very long time. This creates embryonic stem cell lines. Under the right conditions, the cells can differentiate, which means they can become specialized cells. They may do this on their own or through directed differentiation into a chosen cell type.

Scientists guide this process by changing the culture conditions. They may alter the surface of the culture dish, add specific growth factors to the medium, or genetically modify the cells. Using these methods, researchers have made blood, nerve, heart, bone, liver, and pancreas cells from embryonic stem cells.

These cells also have an important role in regenerative medicine, which aims to create living, functional tissues to replace dead, diseased, or malfunctioning ones. This field is still in early stages, but some cell types made from embryonic stem cells have already been tested in clinical studies. Some results have been promising, including reports of paralyzed patients regaining some movement after receiving nervous system cells made from embryonic stem cells. Researchers also use these cells to study early human development and to provide specific cell types for drug testing and other scientific research.

How Embryonic Stem Cells Become Specialized

how-embryonic-stem-cells-become-specialized

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key terms and concepts

Explore how embryonic stem cells are grown, guided to specialize, and used in regenerative medicine, development studies, and drug testing.

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How Embryonic Stem Cells Become Specialized

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