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

Embryonale Stamm- oder ES-Zellen sind undifferenzierte Zellen, die aus der inneren Zellmasse einer Blastozyste stammen, einem drei bis fünf Tage alten Embryo.
 Sie sind pluripotent, was bedeutet, dass sie alle verschiedenen Zelltypen im Körper produzieren können, von Blut bis zu Gehirnzellen, wodurch sie eine Vielzahl von Einsatzmöglichkeiten in Wissenschaft und Medizin bieten.
 Sie werden entfernt und in Kulturen gezüchtet, wo sie sich unbegrenzt teilen und neue Stammzellen produzieren können.
 Durch Manipulation der Kulturbedingungen, beispielsweise durch Zugabe bestimmter Wachstumsfaktoren, können die Zellen dazu gebracht werden, sich in bestimmte Zelltypen zu differenzieren.
 Diese neuen Zellen könnten möglicherweise verwendet werden, um Zellen im Körper zu ersetzen, die aufgrund von Schäden oder Krankheiten verloren gegangen sind, beispielsweise die Insulin produzierenden Zellen der Bauchspeicheldrüse, die bei Typ-1-Diabetes zerstört werden.

Ilic, Dusko und Caroline Ogilvie. "Concise Review: Menschliche embryonale Stammzellen – was haben wir getan? Was machen wir? Wohin gehen wir?" STEM CELLS 35, Nr. 1 (2017): 17–25. [<a href="https://doi.org/10.1002/stem.2450" target="__blank">Quelltext</a>]

embryonale stammzellen

Embryonic Stem Cells

Embryonale Stammzellen (ES) sind undifferenzierte pluripotente Zellen. Das heißt, dass sie können jeden Zelltyp im Körper produzieren. Dies gibt ihnen ein enormes Potenzial in Wissenschaft und Medizin, da sie spezifische Zelltypen erzeugen, die in der Forschung verwendet werden oder um Körperzellen zu ersetzen, die beschädigt oder erkrankt sind.
 
 <h4>Ursprung</h4>
 
 ES-Zellen sind in der inneren Zellmasse eines Embryos während des Blastozystenstadiums vorhanden. Dieses Stadium tritt etwa 3-5 Tagen nach der Befruchtung beim Menschen auf,<y jedoch bevor der Embryo in die Gebärmutter eingepflanzt wird. Menschliche ES-Zellen werden normalerweise aus gespendeten Embryonen gewonnen, die bei der In-vitro-Fertilisation (IVF) übrig geblieben sind.
 
 Die Zellen werden gesammelt und als Kultur gewachsen, wo sie sich unbegrenzt teilen können, wodurch ES-Zelllinien entstehen. Unter bestimmten Bedingungen können sich ES-Zellen differenzieren. Dies geschieht entweder spontan in eine Vielzahl von Zelltypen, oder gezielt zur Herstellung gewünschter Zelltypen. Die Wissenschaftler können beeinflussen, welche Zelltypen erzeugt werden, indem sie die Kulturbedingungen manipulieren, wie zum Beispiel die Veränderung der Oberfläche der Kulturschale oder durch das Zugeben von spezifischen Wachstumsfaktoren in das Kulturmedium. Die Zellen können auch genetisch manipuliert werden. Mit diesen Methoden konnten die Forscher viele spezifische Zelltypen aus ES-Zellen erzeugen. Dazu gehören Blut-, Nerven-, Herz-, Knochen-, Leber-und Pankreaszellen.
 
 <h4>Regenerative Medizin</h4>
 
 Die regenerative Medizin befasst sich mit der Schaffung von lebenden, funktionstüchtigen Geweben als Ersatz für tote, kranke oder schlecht funktionierende Gewebe. ES-Zellen werden aufgrund ihrer Fähigkeit, sich in jeden Zelltyp zu differenzieren, in der regenerativen Medizin eingesetzt. Obwohl sich dieses Feld der Medizin noch im Anfangsstadium befindet, wurden bereits mehrere potenziell nützliche Zelltypen aus ES-Zellen hergestellt und klinische Studien werden durchgeführt um ihre Sicherheit und Wirksamkeit bei Patienten zu testen. Einige erste Ergebnisse waren vielversprechend. Zum Beispiel konnten gelähmte Patienten, nach dem Erhalt von ES-Zellen aus dem Nervensystem, beschränkt bewegen. Darüber hinaus können ES-Zellen zur Untersuchung früher Ereignisse in der menschlichen Entwicklung verwendet werden. Das ist ansonsten sehr schwierig. Außerdem stellen sie eine Quelle für spezifische Zelltypen dar, die in Arzneimitteltests und anderen wissenschaftlichen Forschungen verwendet werden können.

Embryonale Stammzellen

Embryonale Stammzellen (ES) sind undifferenzierte pluripotente Zellen, was bedeutet, dass sie jeden Zelltyp im Körper produzieren können. Das gibt ihnen ein enormes Potenzial ...

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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

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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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