Name: reprogramming mature cells into stem cells
Uploaded: 2019-03-11T09:21:22.000Z
Duration: 1 min 13 s
Channel: JoVE

Indukowane pluripotencjalne komórki macierzyste, iPSC, to dojrzałe, zróżnicowane komórki, takie jak komórki skóry, które są przeprogramowywane w laboratorium tak, aby były podobne do niezróżnicowanych embrionalnych komórek macierzystych. Oznacza to, że dzielą się i są pluripotencjalne, zdolne do wytwarzania dowolnego typu komórek w organizmie. Na przykład komórki siatkówki, które można wykorzystać do zastąpienia uszkodzonej tkanki siatkówki.

Aby wytworzyć iPSC, dojrzałe komórki, takie jak fibroblasty skóry, są pobierane od pacjenta i umieszczane w hodowli. Następnie, zazwyczaj, geny czynników transkrypcyjnych są dostarczane przez wektory wirusowe do jąder komórkowych, gdzie są włączane do genomu.

Czynniki transkrypcyjne włączają następnie geny, które ulegają ekspresji przez embrionalne komórki macierzyste. Skutecznie, odróżnicowując je i doprowadzając do stanu pluripotencjalnego.

Komórki mogą się teraz dzielić, a najlepiej być kierowane w celu wytworzenia określonego typu komórek w hodowli. Nowe komórki mogą być następnie przeszczepione z powrotem do pacjenta w celu leczenia uszkodzeń lub choroby przy minimalnym ryzyku odrzucenia, ponieważ pochodzą z własnych komórek pacjenta.

Hamazaki, Takashi, Nihal El Rouby, Natalie C. Fredette, Katherine E. Santostefano i Naohiro Terada. "Zwięzły przegląd: Indukowane badania pluripotencjalnych komórek macierzystych w erze medycyny precyzyjnej". Stem Cells (Dayton, Ohio) 35, nr 3 (marzec 2017): 545–50. [<a href="https://doi.org/10.1002/stem.2570" target="__blank">Źródło</a>].

indukowane pluripotencjalne komórki macierzyste

Induced Pluripotent Stem Cells

Komórki macierzyste to niezróżnicowane komórki, które dzielą się i wytwarzają różne typy komórek. Zwykle komórki, które różnicowały się w określony typ komórek, przechodzą proces postmitotyczny“co oznacza, że nie dzielą się już. Naukowcy znaleźli jednak sposób na przeprogramowanie tych dojrzałych komórek, tak aby “odróżnicowały się” i powróciły do niewyspecjalizowanego stanu proliferacyjnego. Komórki te są również pluripotencjalne, podobnie jak embrionalne komórki macierzyste — zdolne do wytwarzania wszystkich typów komórek — i dlatego nazywane są indukowanymi pluripotencjalnymi komórkami macierzystymi (iPSC).

Komórki iPSC są potencjalnie cenne w medycynie, ponieważ pacjent potrzebujący określonego typu komórek — na przykład ktoś z uszkodzoną siatkówką w wyniku zwyrodnienia plamki żółtej — może otrzymać przeszczep wymaganych komórek, wygenerowanych z innego typu komórek w jego własnym organizmie. Nazywa się to przeszczepieniem autologicznym i zmniejsza ryzyko odrzucenia przeszczepu, które może wystąpić w przypadku przeszczepiania tkanek między osobami.

<h4>Proces</h4>

Aby wytworzyć iPSC, w hodowli hoduje się dojrzałe komórki, takie jak fibroblasty skóry lub komórki krwi danej osoby. Następnie geny wielu czynników transkrypcyjnych są dostarczane do komórek za pomocą wektora wirusowego, a białka czynników transkrypcyjnych ulegają ekspresji przy użyciu maszynerii komórkowej. Czynniki transkrypcyjne następnie włączają wiele innych genów ulegających ekspresji w embrionalnych komórkach macierzystych, przywracając komórki do stanu niezróżnicowanego, proliferacyjnego i pluripotencjalnego.

Nadal bada się, czy iPSC są rzeczywiście równoważne embrionalnym komórkom macierzystym, ale wydają się podobne i mogą wytwarzać komórki ze wszystkich trzech listków zarodkowych organizmu. Podobnie jak w przypadku innych typów komórek macierzystych, naukowcy uczą się, jak skutecznie promować różnicowanie określonych typów komórek od iPSC, aby można było wytwarzać potrzebne typy komórek w odpowiednich ilościach.

<h4>Wczesne badania kliniczne</h4>

W pierwszym badaniu klinicznym przeszczepiono komórki siatkówki pochodzące z iPSC pacjentom ze zwyrodnieniem plamki związanym z wiekiem. Od tego czasu zatwierdzono kilka badań klinicznych iPSC w leczeniu choroby Parkinsona, chorób serca i uszkodzeń rdzenia kręgowego. Komórki pobrane od pacjentów i przekształcone w iPSC są również wykorzystywane do badania ich chorób w laboratorium. Ogólnie rzecz biorąc, iPSC stanowią kolejne źródło komórek macierzystych do badań naukowych.

Indukowane pluripotencjalne komórki macierzyste

Komórki macierzyste to niezróżnicowane komórki, które dzielą się i wytwarzają różne typy komórek. Zwykle komórki, które zróżnicowały się w określoną komórkę ...

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reprogramming mature cells into stem cells

Reprogramming mature cells into stem cells lets scientists turn specialized cells back into an unspecialized state. These cells are called induced pluripotent stem cells, or iPSCs. Like embryonic stem cells, iPSCs are pluripotent, which means they can form all cell types.

To make iPSCs, researchers start with mature cells such as skin fibroblasts or blood cells. The cells are grown in culture, and genes for several transcription factors are delivered with a viral vector. The cells then make those transcription factor proteins, which switch on other genes that are active in embryonic stem cells and return the cells to a proliferative, undifferentiated, and pluripotent state.

iPSCs may be useful in medicine because they can come from a patient’s own body. For example, cells needed to repair a damaged retina in age-related macular degeneration could be made from that same patient’s cells. This autologous transplantation lowers the risk of transplant rejection that can happen when tissue is moved between different people.

Scientists are still studying whether iPSCs are truly equivalent to embryonic stem cells, but they appear to be similar and can produce cells from all three germ layers. Researchers are also working on ways to direct iPSCs to become specific cell types in efficient amounts. Early clinical trials have used iPSC-derived retinal cells for macular degeneration, and other trials have been approved for Parkinson’s disease, heart disease, and spinal cord injury. Patient cells turned into iPSCs are also helping scientists study disease in the lab.

Reprogramming Mature Cells into Stem Cells

reprogramming-mature-cells-into-stem-cells

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induced pluripotent stem cells

Reprogramming mature cells into stem cells lets scientists turn specialized cells back into an unspecialized state. These cells are called induced pluripotent stem cells, or iPSCs. Like embryonic stem cells, iPSCs are pluripotent, which means they can form all cell types. To make iPSCs, researchers start with mature cells such as skin fibroblasts or blood cells. The cells are grown in culture, and genes for several transcription factors are delivered with a viral vector. The cells then make...

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key terms and concepts

Learn how mature cells are reprogrammed into induced pluripotent stem cells, why iPSCs matter for transplants, and how they are used in research and clinical trials.

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Reprogramming Mature Cells into Stem Cells

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