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

الخلايا الجذعية المحفزة المستحثة iPSCs هي خلايا ناضجة ومتمايزة مثل خلايا الجلد التي يتم إعادة برمجتها في المختبر لتكون مماثلة إلى الخلايا الجذعية الجنينية غير متمايزة. وهذا هو وهم يقسمون والمتفوقين قادرة على إنتاج أي نوع من الخلايا في الجسم. على سبيل المثال خلايا الشبكية التي يمكن استخدامها ليحل محل الأنسجة التالفة في شبكية العين.لإنشاء iPSCs الخلايا الناضجة مثل الخلايا الليفية في الجلد تؤخذ من المريض ووضعها في الثقافة. ثم عادة الجينات لعوامل النسخ يتم تسليمها عن طريق ناقلات الفيروسية في نواة الخلية حيث يتم دمجها في الجينوم. عوامل النسخ ثم تشغيل الجينات التي تعبر عنها الخلايا الجذعية الجنينية.على نحو فعال التراجع عنهم وإحضارهم إلى دولة متعددة القدرات. يمكن أن تقسم الخلايا الآن وبشكل مثالي يتم توجيهها لإنتاج نوع خلية معين في الثقافة. ويمكن بعد ذلك زرع الخلايا الجديدة مرة أخرى في المريض لعلاج الضرر أو المرض مع الحد الأدنى من خطر الرفض لأنها نشأت من خلايا المريض نفسه.

همزاكي ، تاكاشي ، نهال الروبي ، ناتالي سي فريديت ، كاثرين إي سانتوستيفانو ، وناوهيرو تيرادا. "مراجعة موجزة: أبحاث الخلايا الجذعية المستحثة متعددة القدرات في عصر الطب الدقيق." الخلايا الجذعية (دايتون ، أوهايو) 35 ، العدد 3 (مارس 2017): 545-50. [<a href = "https://doi.org/10.1002/stem.2570" target = "__blank" >المصدر</a>].

خلايا جذعية بقوة نفاذية خلوية محفزة

Induced Pluripotent Stem Cells

الخلايا الجذعية هي خلايا غير متمايزة تنقسم وتنتج أنواعاً مختلفة من الخلايا. عادةً ما تكون الخلايا التي تمايزت في نوع خلية معين بعد الانقسام الخيطي _ أي أنها لم تعد تنقسم. ومع ذلك ، فقد وجد العلماء طريقة لإعادة برمجة هذه الخلايا الناضجة بحيث ”تفك تمايزها“ والعودة إلى حالة تكاثرية غير متخصصة. هذه الخلايا هي أيضا متعددة القدرات مثل الخلايا الجذعية الجنينية _ قادرة على إنتاج جميع أنواع الخلايا _ وبالتالي تسمى الخلايا الجذعية المستحثة (iPSCs).

من المحتمل أن تكون الخلايا الجذعية المستحثة ذات قيمة في الطب ، لأن المريض الذي يحتاج إلى نوع معين من الخلايا _ على سبيل المثال ، شخص مصاب بشبكية تالفة بسبب الضمور البقعي _ يمكن أن يتلقى زرع الخلايا المطلوبة ، المتولدة من نوع خلية آخر في جسمه. وهذا ما يسمى بالزرع الذاتي ، وهو يقلل من خطر رفض الزرع الذي يمكن أن يحدث عندما يتم زرع الأنسجة بين الأفراد.

<h4>العملية</h4>

لإنشاء خلايا الخلايا الجذعية المستحثة ، يتم زراعة الخلايا الناضجة مثل الخلايا الليفية الجلدية أو خلايا الدم من شخص في المزرعة. بعد ذلك ، يتم تسليم جينات عوامل النسخ المتعددة إلى الخلايا باستخدام ناقل فيروسي ، ويتم التعبير عن بروتينات عامل النسخ باستخدام آلية الخلية. تعمل عوامل النسخ بعد ذلك على تشغيل العديد من الجينات الأخرى التي يتم التعبير عنها بواسطة الخلايا الجذعية الجنينية ، مما يعيد الخلايا إلى حالة غير متمايزة وتكاثرية ومتعددة القدرات.

لا يزال يتم دراسة ما إذا كانت الخلايا الجذعية المستحثة مكافئة حقاً للخلايا الجذعية الجنينية ، لكنها تبدو متشابهة ويمكنها إنتاج خلايا من الطبقات الجرثومية الثلاث في الجسم. كما هو الحال مع الأنواع الأخرى من الخلايا الجذعية ، يتعلم العلماء كيفية تعزيز تمايز أنواع معينة من الخلايا من خلايا الخلايا الجذعية المستحثة بكفاءة ، بحيث يمكن إنتاج أنواع الخلايا المطلوبة بكميات كافية.

<h4>التجارب السريرية المبكرة</h4>

قامت أول تجربة إكلينيكية بزرع خلايا شبكية مشتقة من الخلايا الجذعية المستحثة في مرضى يعانون من التنكس البقعي المرتبط بالعمر. منذ ذلك الحين ، تمت الموافقة على العديد من التجارب السريرية للخلايا الجذعية المستحثة لعلاج مرض باركنسون وأمراض القلب وإصابة الحبل الشوكي. يتم أيضاً استخدام الخلايا المأخوذة من المرضى وتحويلها إلى خلايا جذعية مستحثة لدراسة أمراضهم في المختبر. بشكل عام ، توفر الخلايا الجذعية المستحثة مصدراً آخر للخلايا الجذعية للبحث العلمي.

الخلايا الجذعية هي خلايا غير متمايزة تنقسم وتنتج أنواعا مختلفة من الخلايا. عادة ، الخلايا التي تمايزت إلى خلية معينة ...

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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.

Reprogramming Mature Cells into Stem Cells | JoVE K12

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Reprogramming Mature Cells into Stem Cells

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