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Embryonale Stammzellen
Embryonale Stammzellen (ES) sind undifferenzierte pluripotente Zellen. Das heißt, dass sie können jeden Zelltyp im Körper produzieren. Dies gibt ihnen…
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.
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Q1: What are embryonic stem cells and where do they come from?
Embryonic stem (ES) cells are undifferentiated cells derived from the inner cell mass of a blastocyst, a three to five day old embryo. In humans, they are typically obtained from donated embryos left over from in vitro fertilization (IVF). These cells are pluripotent, meaning they can produce any cell type in the body, making them valuable for research and medical applications.
Q2: Why are embryonic stem cells considered pluripotent?
Embryonic stem cells are pluripotent because they can differentiate into all the different cell types found in the body, from blood to brain cells. This unique capability arises from their undifferentiated state and their origin in the early embryo. Their pluripotency gives them tremendous potential in science and medicine for generating specific cell types needed for research or therapy.
Q3: How do scientists control which cell types embryonic stem cells become?
Scientists manipulate culture conditions to direct embryonic stem cell differentiation into specific cell types. They can change the surface of the culture dish, add specific growth factors to the culture medium, or genetically modify the cells. These methods allow researchers to generate desired cell types including blood, nerve, heart, bone, liver, and pancreas cells for research and therapeutic use.
Q4: How can embryonic stem cells be used in regenerative medicine?
Regenerative medicine uses embryonic stem cells to create living, functional tissues that replace dead, diseased, or malfunctioning ones. Because ES cells can differentiate into any cell type, they can generate replacement tissues for various organs and tissues. Clinical studies have shown promising results, including paralyzed patients regaining movement after receiving ES-derived nervous system cells.
Q5: Can embryonic stem cells divide indefinitely in culture?
Yes, embryonic stem cells can divide indefinitely when grown in culture, producing new stem cells continuously. This property allows researchers to create ES cell lines—stable populations of cells that can be maintained and expanded over long periods. This unlimited proliferation capacity makes ES cells particularly valuable for large-scale research and therapeutic applications.
Q6: What medical conditions could potentially be treated with embryonic stem cells?
Embryonic stem cells could potentially treat conditions where specific cell types are destroyed or lost due to disease or damage. For example, Type One diabetes could be addressed by generating insulin-producing pancreatic cells from ES cells. Additionally, ES cells can replace damaged nerve cells in spinal cord injuries and other tissues affected by degenerative diseases or injury.
Q7: How are embryonic stem cells used in scientific research beyond medicine?
Embryonic stem cells serve multiple research purposes beyond regenerative medicine. They enable scientists to study early events in human development, which is otherwise difficult to observe directly. ES cells also provide a source of specific cell types for drug testing and other scientific research, helping researchers understand disease mechanisms and evaluate potential therapeutic compounds.