Introducing stem cells
Dear speaker…
This presentation is intended as a flexible tool for scientists, science communicators and
educators. Not all the slides will be useful for any one occasion. Choose the ones most
suitable for your audience, mix them with your own slides, or just use the diagrams.
Contents
Stem cell biology basics: For school students aged 16+, or adult public with little or
no scientific knowledge
Cloning: For adult public with little or no scientific knowledge; initial slides also
suitable for students aged 16+
Stem cell biology in more detail: For informed non-specialist audiences, e.g.
clinicians, scientists working in fields other than stem cell biology.
Presenter’s notes
Each slide in the Basics and Cloning sections includes notes that give a simple, jargonfree explanation of the key points. The more detailed slides in the last section have much
briefer notes and assume some knowledge of stem cell science.
Further information and resources
The 15-minute film, “A Stem Cell Story” provides an excellent introduction to stem cells
and covers many of the concepts presented here. See www.eurostemcell.org/films
Got a question or a comment? Contact us at http://www.eurostemcell.org/contact
Stem cell biology basics
A life story…
What is a stem cell?
stem cell
SELF-RENEWAL
(copying)
stem cell
DIFFERENTIATION
(specializing)
specialized cell
e.g. muscle cell, nerve cell
What is a stem cell?
Stem cell
SELF-RENEWAL
(copying)
Identical stem cells
Stem cell
DIFFERENTIATION
(specializing)
Specialized cells
Why self-renew AND differentiate?
1 stem cell
1 stem cell
Self renewal - maintains
the stem cell pool
4 specialized cells
Differentiation - replaces dead or damaged
cells throughout your life
Where are stem cells found?
embryonic stem cells
blastocyst - a very early
embryo
tissue stem cells
fetus, baby and throughout life
Types of stem cell:
1) Embryonic stem cells
Embryonic stem (ES) cells:
Where we find them
blastocyst
cells inside
= ‘inner cell mass’
embryonic stem cells taken from
the inner cell mass
outer layer of cells
= ‘trophectoderm’
fluid with nutrients
culture in the lab
to grow more cells
Embryonic stem (ES) cells:
What they can do
differentiation
embryonic stem cells
PLURIPOTENT
all possible types of specialized cells
Embryonic stem (ES) cells:
Challenges
skin
neurons
embryonic stem cells
blood
?
liver
Types of stem cell:
2) Tissue stem cells
Tissue stem cells:
Where we find them
surface of the eye
skin
testicles
brain
breast
intestines (gut)
bone marrow
muscles
Tissue stem cells:
What they can do
blood stem cell
differentiation
found in
bone marrow
MULTIPOTENT
only specialized types of blood cell:
red blood cells, white blood cells,
platelets
Types of stem cell:
3)Induced pluripotent (iPS)
stem cells
Induced pluripotent stem cells (iPS cells)
‘genetic reprogramming’
= add certain genes to the cell
cell from the body
induced pluripotent stem (iPS) cell
behaves like an embryonic stem cell
differentiation
culture iPS cells in the lab
Advantage: no need for embryos!
all possible types of
specialized cells
Induced pluripotent stem cells (iPS cells)
genetic reprogramming
pluripotent stem cell
(iPS)
cell from the body (skin)
differentiation
Stem cell jargon
Potency
A measure of how many types of specialized cell a stem cell
can make
Pluripotent
Can make all types of specialized cells in the body
Embryonic stem cells are pluripotent
Multipotent Can make multiple types of specialized cells, but not all types
Tissue stem cells are multipotent
Cloning
Cloning
There are two VERY different types of cloning:
Reproductive cloning
Molecular cloning
gene 1
gene 2
Use to make two identical individuals
Use to study what a gene does
Very difficult to do
Routine in the biology labs
Illegal to do on humans
Reproductive cloning
cell from the body
egg
remove nucleus
and take the
rest of the cell
take the nucleus
(containing DNA)
Clone
identical to the individual
that gave the nucleus
Dolly the sheep
Molecular cloning: Principles
1) Take DNA out of the nucleus
gene 1
cell 1
gene 2
cell 2
2) Make a new piece of DNA
gene 1
gene 1
gene 2
gene 2
3) Put new DNA into a test cell and grow copies
gene 1
Daughter cells
contain same DNA:
gene 2
insert new DNA
cell divides
Genes 1 and 2 have
been cloned
Molecular cloning: Applications
Loss of function
Reporter gene
Lineage tracing
remove a gene to see if
anything works differently
add a gene that shows
us when another gene is
working
mark a group of cells to
see where their
daughter cells end up
gene is active in blue
areas only
gene is passed on
to cells all over the body
eye
Normal mouse
embryo
gene A missing
gene is involved in
giving the eye its colour
Stem cell biology in more detail
Tissue stem cell types
and hierarchies
Tissue stem cells:
Principles of renewing tissues
Stem cell
stem cell:
- self renew
- divide rarely
- high potency
- rare
committed progenitors:
- “transient amplifying cells”
- multipotent
- divide rapidly
- no self-renewal
specialized cells:
- work
- no division
Tissue stem cells:
Haematopoietic stem cells (HSCs)
NK cell
T cell
B cell
dendritic cell
megakaryocyte
HSC
platelets
erythrocytes
macrophage
neutrophil
bone marrow
eosinophil
basophil
committed progenitors
specialized cells
Tissue stem cells:
Neural stem cells (NSCs)
Neurons
Interneurons
Oligodendrocytes
NSC
Type 2 Astrocytes
Type 1 Astrocytes
brain
committed progenitors
specialized cells
Tissue stem cells:
Gut stem cells (GSCs)
Paneth cells
Goblet cells
GSC
Endocrine cells
Columnar cells
Small intestine
committed progenitors
specialized cells
Tissue stem cells:
Mesenchymal stem cells (MSCs)
Bone (osteoblasts)
Cartilage (chondrocytes)
MSC
bone marrow
Fat (adipocytes)
committed progenitors
specialized cells
Stem cells at home:
The stem cell niche
Stem cell niches
Niche
stem cell
Microenvironment around stem cells that provides
support and signals regulating self-renewal and
differentiation
Direct contact
Soluble factors
niche
Intermediate cell
Credits
Picture credits
Many thanks to the following people for permission to reproduce images:
Slide 17, iPS cells: Keisuke Kaji, University of Edinburgh, UK
Slide 27, blood cell diagrams: Jonas Larsson, Lund Univeristy, Sweden
Slide 29, intestinal cell diagrams: Hans Clevers and Nick Barker, Hubrecht
Institute, The Netherlands
Should you wish to re-use any of the images listed above, please contact the
owner. All other images in this presentation can be re-used freely.
Acknowledgements
Particular thanks to Dr Christele Gonneau for creating these slides and
working tirelessly to help ensure the notes are correct.
Thanks also to Freddy Radtke of EPFL, Switzerland, whose slide we copied to
make slide 27 on tissue stem cells.