stem_cells_presentation by helal abu-el-zahab

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/