introducing of stem cell classification and biology 1.ppt

Stem cells are a special type of cells that have two important properties. They are able to make more cells like themselves. That is, they self-renew. And they can become other cells that do different things in a process known as differentiation. Stem cell transplants are used to treat conditions in which the bone marrow is damaged and is no longer able to produce healthy blood cells. Transplants can also be carried out to replace blood cells that are damaged or destroyed as a result of intensive cancer treatment. These are: from blood – where the stem cells are removed from the blood using a special machine. from bone marrow – where a procedure is carried out to remove a sample of bone marrow from the hip bone. Yes, stem cell research is legal in the United States, but it faces specific restrictions and regulations. The main controversy and regulation focus on embryonic stem cell research. Embryonic stem cell research is not illegal. Federal funding is prohibited if it involves creating or destroying embryos.

1. Introducing stem cells

2. Stem cell biology basics

3. A life story…

4. stem cell
What is a stem cell?
stem cell
SELF-RENEWAL
(copying)
specialized cell
e.g. muscle cell, nerve cell
DIFFERENTIATION
(specializing)

5. 1 stem cell
Self renewal - maintains
the stem cell pool
4 specialized cells
Differentiation - replaces dead or damaged
cells throughout your life
Why self-renew AND differentiate?
1 stem cell

6. Where are stem cells found?
embryonic stem cells
blastocyst - a very early
embryo
tissue stem cells
fetus, baby and throughout life

7. Types of stem cell:
1) Embryonic stem cells

8. Embryonic stem (ES) cells:
Where we find them
blastocyst
outer layer of cells
= ‘trophectoderm’
cells inside
= ‘inner cell mass’
embryonic stem cells taken from
the inner cell mass
culture in the lab
to grow more cells
fluid with nutrients

9. Embryonic stem (ES) cells:
What they can do
embryonic stem cells
PLURIPOTENT
all possible types of specialized cells
differentiation

10. neurons
grow under conditions B
Embryonic stem (ES) cells:
Challenges
embryonic stem cells
skin
grow under conditions A
blood
grow
under conditions C
liver
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11. Types of stem cell:
2) Tissue stem cells

12. Tissue stem cells:
Where we find them
muscles
skin
surface of the eye brain
breast
intestines (gut)
bone marrow
testicles

13. Tissue stem cells:
What they can do
MULTIPOTENT
blood stem cell
found in
bone marrow
differentiation
only specialized types of blood cell:
red blood cells, white blood cells,
platelets

14. Types of stem cell:
3)Induced pluripotent (iPS)
stem cells

15. Induced pluripotent stem cells (iPS cells)
cell from the body
‘genetic reprogramming’
= add certain genes to the cell
induced pluripotent stem (iPS) cell
behaves like an embryonic stem cell
Advantage: no need for embryos!
all possible types of
specialized cells
culture iPS cells in the lab
differentiation

16. Induced pluripotent stem cells (iPS cells)
cell from the body (skin)
genetic reprogramming
pluripotent stem cell
(iPS)
differentiation

17. Stem cell jargon
Potency A measure of how many types of specialized cell a stem cell
can make
PluripotentCan make all types of specialized cells in the body
Embryonic stem cells are pluripotent
MultipotentCan make multiple types of specialized cells, but not all types
Tissue stem cells are multipotent

18. Cloning

19. Cloning
There are two VERY different types of cloning:
Reproductive cloning
Use to make two identical individuals
Very difficult to do
Illegal to do on humans
Molecular cloning
Use to study what a gene does
Routine in the biology labs
gene 1
gene 2

20. Reproductive cloning
remove nucleus
and take the
rest of the cell
egg
take the nucleus
(containing DNA)
cell from the body
Clone
identical to the individual
that gave the nucleus
Dolly the sheep

21. Molecular cloning: Principles
gene 1
gene 2
2) Make a new piece of DNA
gene 1
gene 2
1) Take DNA out of the nucleus
cell 1 cell 2
gene 1 gene 2
3) Put new DNA into a test cell and grow copies
gene 1
cell divides
Daughter cells
contain same DNA:

Genes 1 and 2 have
been cloned
gene 2
insert new DNA

22. Molecular cloning: Applications
Normal mouse
embryo
gene A missing
remove a gene to see if
anything works differently
Loss of function
gene is involved in
giving the eye its colour
eye
Reporter gene
add a gene that shows
us when another gene is
working
gene is active in blue
areas only
Lineage tracing
mark a group of cells to
see where their
daughter cells end up
gene is passed on
to cells all over the body

23. Stem cell biology in more detail

24. Tissue stem cell types

25. Tissue stem cells:
Principles of renewing tissues
Stem cell
committed progenitors:
- “transient amplifying cells”
- multipotent
- divide rapidly
- no self-renewal
stem cell:
- self renew
- divide rarely
- high potency
- rare
specialized cells:
- work
- no division

26. Tissue stem cells:
Haematopoietic stem cells (HSCs)
HSC
committed progenitors
neutrophil
NK cell
erythrocytes
dendritic cell
plateletsmegakaryocyte
macrophage
eosinophil
basophil
B cell
T cell
specialized cells
bone marrow

27. Tissue stem cells:
Neural stem cells (NSCs)
NSC
brain
committed progenitors specialized cells
Neurons
Interneurons
Oligodendrocytes
Type 2 Astrocytes
Type 1 Astrocytes

28. Tissue stem cells:
Gut stem cells (GSCs)
GSC
Small intestine
committed progenitors
Paneth cells
Columnar cells
Goblet cells
Endocrine cells
specialized cells

29. Tissue stem cells:
Mesenchymal stem cells (MSCs)
MSC
bone marrow
committed progenitors
Bone (osteoblasts)
Cartilage (chondrocytes)
Fat (adipocytes)
specialized cells

30. Stem cells at home:
The stem cell niche

31. Stem cell niches
Direct contact Soluble factors Intermediate cell
stem cell
niche
Niche
Microenvironment around stem cells that provides
support and signals regulating self-renewal and
differentiation