stem_cells_presentation by helal abu-el-zahab
TRANSCRIPT
STEM CELLS
الخاليا الجذعيةBy
Prof. Helal S.H. Abuelzahab
Professor of Physiology
Stem Cell
• In 1998 - Researchers first extract stem cells from human embryos
• A cell that has the ability to continuously divide and differentiate
(develop) into various other kind(s) of cells/tissues
‘Blank cells’ (unspecialized)
Capable of dividing and renewing themselves
for long periods of time (proliferation and
renewal)
Have the potential to give rise to specialized
cell types (differentiation)
Stem Cell–الخلية الجذعية
Fertilization-اإلخصاب
Stages of Embryogenesis
Blastocyst Blastocyst inner mass cells
8-cell stageCleavage
Cleavage-نقسام إلا
الخاليا الجذعيةStem Cells
(ESC)الجنينيةالخاليا الجذعية
Embryonic Stem cells)Pluripotent Stem Cells(
البالغةالخاليا الجذعية
Adult stem cells(Tissue-specific Stem Cells)
(Multipotent)
Classifications of stem cells
Stem cell type Description Examples
Totipotent
خلية جذعية ذات قدرة كلية
Each cell can
develop into a new
individual
Cells from
early (1-3 days)
embryos
Pluripotent
خلية جذعية عديدة القدرات
Cells can form any
(over 220) cell
types
Some cells of
blastocyst (5 to
14 days)
Multipotent
القدرات عديدة خلية جذعية
عدد ولكن تستطيع تكوين
أنسجة أخريمحدود من
Cells differentiated,
but can form a
limited number of
other tissues
Fetal tissue,
cord blood,
and adult stem
cells
Unipotent
خلية جذعية وحيدة القدرة
Cells can
differentiated to
only one cell type
This cell
Can form the
Embryo and placenta
Fully mature
Source of Stem cells
Embryonic :
• Blastocyst
Adult:
• Placental stem cells
• Umbilical cord blood
• Bone marrow stem cells
(ESC)الجنينيةالخاليا الجذعية
Embryonic Stem cells)Pluripotent Stem Cells(
• Embryonic human stem cells werefirst isolated in 1995 by Dr. JamesThomson.
• Source of ESC is Blastocysts.
Embryonic Stem Cells
• Pluripotent stem cells can become any kind of tissue
in the body.
• Pluripotent stem cell has the capacity to become any
one of the 220 human cell types.
البالغةالخاليا الجذعية
Adult stem cells(Tissue-specific Stem Cells)
(Multipotent)
• Found in specific mature body tissues as
well as the umbilical cord and placenta
after birth.
• They also can be isolated from developing
embryos’ different tissues
Plasticity of adult stem cells
Examples of Adult stem cells(Tissue-specific Stem Cells) (Multipotent)
ةالميزانشيميالخاليا الجذعية
Mesenchymal stem cells
الجلديةالخاليا الجذعية
Epidermal stem cells
الدمويةالخاليا الجذعية
Hematopoietic stem cells
العصبيةالخاليا الجذعية
Neural stem cells
found in bone marrow are the
source of all kinds of blood
cells, including red blood
cells and white blood cells.
are a source of bone cells,
cartilage, fat cells, and
tendons.
are found beneath the skin and
at the base of hair follicles;
these stem cells form the
protective outer layer of your
skin as well as hair follicles.
are the source of all neurons
as well as two kinds of cells
that support nerves in the
brain and spinal cord
الدمويةالخاليا الجذعية
Hematopoietic Stem Cells
الميزانشيميةالخاليا الجذعية
Mesenchymal Stem Cells
الميزانشيميةالخاليا الجذعية
Mesenchymal Stem Cells
العصبيةالخاليا الجذعية
Neural Stem Cells
النقاط الزرقاء
هي الخاليا الجذعية العصبية
الجلديةالخاليا الجذعية
Epidermal Stem Cells
على الحصول وتكثيرهاالخاليا الجذعية زرع -
المرضى المصابينثم تزرع عند جلديةطبقة
بالحروق
:ولكن
تكلفة عالية -
(sweat glands)ال تحتوي غدد عرقية -
وال تحتوي جريبات شعرية -
-«hair follicles»
Stem Cells from Bone Marrow
• Found in spongy bone where blood cells form
• Used to replace damaged or destroyed bone
marrow with healthy bone marrow stem cells.
• Treat patients diagnosed with leukemia,
aplastic anemia, and lymphomas
• Need a greater histological immunocompatibility
دم الحبل السريخاليا جذعية من
Umbilical cord stem cells
لمولود من أوردة الحبل السري لخاليا الجذعية الوي على تححيث يتم سحب دم ي•
نقله فييتم ثم .ملليترا80قبل قطع الحبل السري وحدوث الوالدة بثوان، بحجم
ساعة من لحظة سحبه24الحال بواسطة حافظات خاصة ليجري تجميده خالل
.النتروجينمئوية تحت الصفر، في سائل196-بدرجة
اليا ان الخاليا الجذعية المستمدة من الحبل السري قادرة على انتاج خفقد وجد •
.اعة القلبعضالت القلب ويمكن ان تشكل بديال ناجحا في المستقبل لعمليات زر
نة أو من االجةثبت ان هذه الخاليا تختلف عن الخاليا المأخوذة من المشيموقد
. المجهضة
بل هذه الخاليا اليه قعويمكن معالجة االنسان المصاب بالسرطان عن طريق زر•
.الى معالجته بواسطة الكيميائيات واالشعة النوويةيبان يلجأ الطب
دم الحبل السريخاليا جذعية من
Umbilical cord stem cells
Umbilical cord stem cells
• Also Known as Wharton’s Jelly
• Adult stem cells of infant origin
• Less invasive than bone marrow
• Greater compatibility
• Less expensive
Three important
characters of stem cells
1. Plasticity: Potential to change into other cell types like nerve cells
2. Homing: To travel to the site of tissue damage
3. Engraftment: To unite with other tissues
المستحثةالخاليا الجذعية
Induced pluripotent stem cells (iPSCs)
iPSCs are adult cells that have been changed
by scientists to have the same properties as
embryonic stem cells.
Induced Pluripotent Stem Cells (iPSCs)
cell from the body
‘genetic reprogramming’= add certain genes to the cell
induced pluripotent stem (iPS) cellbehaves like an embryonic stem cell
Stem cell therapy
• Defined as «The use of living cells to restore,maintain or enhance the function of tissuesand organs».
• Cell-based therapy is one of the more recentapproaches in regenerative medicine that aimsat replacing or repairing organs and tissues.
What happens when we get injured, orsomething just wears out?
• Immune cells come in and clear away thedebris and any infection.
• Tissues can repair themselves, filling thevoid with tough but otherwise non-functional material using the body’sequivalent of duct tape: the scar
• Regeneration is the complete restoration ofthe original tissue. Damaged tissue isreplaced by new functional cells.
Tissues regenerate new functional cells by
either dividing the existing functional cells
or by activating an adult stem cell population
A stem cell must make more copies of itself (self-renew) and give rise to more capable offspring (differentiate)
ةاالساسياالسبابوتحديدمعرفةطريقعنوذلكاألمراضدراسة•
لقيةالخوالعيوبالسرطانمثلمميتةامراضفيعادةتتسببالتي
.ينالطبيعيغيروتخصصهاالخالياألنقسامنتيجةتحدثالتي
.االنسانقبلمناستخدامهاقبلالمختلفةاألدويةأختبار•
مايعرفجديدةأعضاءأوجديدةأنسجةبزرعاألمراضمعالجة•
Stem))الخلويبالعالج cell therapyومرضالزهايمرمثل
هابوالتوالسكريالقلبوامراضالشوكيالحبلواصاباتباركسون
والحروقالمفاصل
Regenerative)التجديديالطب• medicine)
:لجذعيةمن التطبيقات الطبية لتقنيات الخاليا ا
The promise of stem cell research
تكوين كبد بشرية باستعمال الخاليا الجذعية
باستعمال الخاليا الجذعيةبشري مختكوين
Induced Pluripotent Stem Cells (iPSCs)
Cell-based therapy-Spinal Cord Injury
Differentiate
(+ growth factors)
START
*Treatment may not work for the chronically paralyzed
time
Oligodendrocytes
Clinical trials starting for treatment
of spinal cord injury* in humans
(after much data gathered using rats
as an animal model)
injuredmarkedly
recovered
Drug Development-Cancer Stem Cells
Reya, T., et al. Nature, 2001
REFERENCES
• http://stemcells.nih.gov/info/scireport/2001report.htm
• http://www.ulb.ac.be/sciences/biodic/biodic/images/bio_animale/embryologie/fecondation/baefec_01_01.jpg
• http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.figgrp.3748
• http://www.news.wisc.edu/packages/stemcells/illustration.html
• http://www.drugs.com/enc/images/images/en/17010.jpg
• http://embryology.med.unsw.edu.au/Notes/placenta.htm
• http://www.dnalc.org/stemcells.html
• http://gslc.genetics.utah.edu/units/stemcells/