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

תאי גזע עובריים, או ES, הם תאים לא ממוינים שמגיעים ממסת התאים הפנימית של בלסטוציסט, עובר בן שלושה עד חמישה ימים. הם פלוריפוטנטיים, כלומר הם יכולים לייצר כל סוגי התאים השונים בגוף, מתאי דם ועד תאי מוח, מה שמקנה להם מגוון רחב של שימושים פוטנציאליים במדע וברפואה. הם מוסרים וגדלים בתרבית, שם הם יכולים להתחלק בלי סוף, ובכך לייצר תאי גזע חדשים.על ידי התערבות בתנאי התרבית, למשל על ידי הוספת גורמי גדילה מסוימים, ניתן לגרום לתאים להתמיין לסוגי תאים ספציפיים. תאים חדשים אלה עשויים לשמש להחלפת תאים בגוף שנאבדו בשל נזק או מחלה, כגון תאי הלבלב המייצרים אינסולין אשר נהרסים בסוכרת מסוג 1.

איליץ', דוסקו וקרוליין אוגילבי. "סקירה תמציתית: תאי גזע עובריים אנושיים – מה עשינו? מה אנחנו עושים? לאן אנחנו הולכים?" תאי גזע 35, מס '1 (2017): 17–25. [<a href="https://doi.org/10.1002/stem.2450" target="__blank">מקור</a>]

תאי גזע עובריים

Embryonic Stem Cells

<div style="direction:rtl">תאי גזע עובריים (ES) הם תאים פלוריפוטנטיים לא מובחנים, כלומר הם יכולים לייצר כל סוג תא בגוף. זה נותן להם פוטנציאל אדיר במדע וברפואה מכיוון שהם יכולים ליצור סוגי תאים ספציפיים לשימוש במחקר או כדי להחליף תאי גוף שאבדו עקב נזק או מחלה. <h4>מקור</h4> תאי ES נמצאים במסת התאים הפנימית של העובר בשלב הבלסטוציסט, המתרחש כ-35 ימים לאחר ההפריה בבני אדם לפני השתלת העובר ברחם. תאי ES אנושיים נגזרים בדרך כלל מעוברים שנתרמו שנשארו מתהליך ההפריה החוץ גופית (IVF). התאים נאספים וגדלים בתרבית, שם הם יכולים להתחלק ללא הגבלת זמן ויוצרים שורות תאים ES. בתנאים מסוימים, תאי ES יכולים להתמיין באופן ספונטני למגוון סוגי תאים, או בצורה מכוונת לייצור סוגי תאים רצויים. מדענים יכולים לשלוט אילו סוגי תאים נוצרים על ידי מניפולציה של תנאי התרבית כגון שינוי פני השטח של צלחת התרבית או הוספת גורמי גדילה ספציפיים למדיום התרבות וכן על ידי שינוי גנטי של התאים. באמצעות שיטות אלה, חוקרים הצליחו ליצור סוגי תאים ספציפיים רבים מתאי ES, כולל דם, עצב, לב, עצם, כבד ותאי לבלב. <h4>רפואה רגנרטיבית</h4> רפואה רגנרטיבית עוסקת ביצירת רקמות חיות ופונקציונליות כדי להחליף רקמות מתות, חולות או לא מתפקדות. בהתחשב ביכולתם להתמיין לכל סוג תא, תאי ES משמשים ברפואה רגנרטיבית. בעוד שתחום זה עדיין בשלבים מוקדמים, הופקו מספר סוגי תאים בעלי פוטנציאל מועיל מתאי ES, ומחקרים קליניים החלו לבדוק את בטיחותם ויעילותם בחולים. כמה תוצאות ראשוניות היו מבטיחות, למשל, חולים משותקים החזירו לעצמם תנועה מסוימת לאחר שקיבלו תאי מערכת העצבים שמקורם ב-ES. בנוסף, ניתן להשתמש בתאי ES כדי לחקור אירועים מוקדמים בהתפתחות האדם, שאחרת היא קשה ומספקת מקור לסוגי תאים ספציפיים שניתן להשתמש בהם בבדיקות סמים ובמחקר מדעי אחר.</div>

תאי גזע עובריים (ES) הם תאים פלוריפוטנטיים בלתי ממוינים, כלומר הם יכולים לייצר כל סוג תא בגוף. זה נותן להם פוטנציאל אדיר...

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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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embryonic stem cells

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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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