A stem cell is a "blank" cell that can give rise to multiple tissue types such as a skin, muscle, or nerve cell. Under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions.

1. PROPERTIES AND USES
OF STEM CELLS
Presented by
Dr.B.Victor., Ph.D.,
Email:bonfiliusvictor@gmail.com,
Blog:bonvictor.blogspot.com.

2. Presentation outline
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Stem cell explanation,
properties
Classes of stem cells
Embryonic stem cells
(ESC)
Adult Stem cells (ASC)
Cord blood stem cells
Cord blood banks
Stem cell therapy
Summary

4. General properties of Stem Cells

5. Unique features of stem cells

7. Three unique properties of
stem cells

8. Stem cells are unspecialized

9. Stem cells are capable of dividing and
renewing themselves for long periods.

10. Stem cells can give rise to
specialized cells
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Differentiation is the process of becoming specialized stem
cells from unspecialized cells.
The signals inside and outside cells that trigger stem cell
differentiation.
The internal signals are controlled by a cell's genes.
The external signals include chemicals secreted by other
cells, physical contact with neighboring cells in the
microenvironment

11. Stem cells exist in both
embryos and adults

12. COMPARISON OF
PROGENITOR/PRECURSOR CELLS
AND STEM CELLS.

13. Distinguishing Features of
Progenitor Cells and Stem Cells.
Stem cells
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A stem cell is an
unspecialized cell that
develops into a variety of
specialized cell types.
a stem cell divides and gives
rise to one additional stem
cell and a specialized cell.
Example: a hematopoietic
stem cell produce a second
generation stem cell and a
neuron.
A progenitor cell
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A progenitor cell is
unspecialized that is capable
of undergoing cell division
and yielding two specialized
cells.
Example: a myeloid
progenitor cell undergoing
cell division to yield two
specialized cells (a neutrophil
and a red blood cell).

14. Sources of stem cells.

15. Embryonic stem cells

16. Sources of embryonic stem cells
* Embryos - Embryonic stem cells are obtained
from
5-7 days old living embryos. The removal of embryonic
stem cells results in the destruction of the embryo.
* Fetuses - Embryonic germ cell, can be obtained from
either miscarriages or aborted fetuses.

17. Adult stem cells

18. Sources of adult stem cells
Adult stem cells can be derived from
Umbilical Cords, Placentas and Amniotic
Fluid.
 Adult stem cells are present within the
bone marrow, liver, epidermis, retina,
skeletal muscle, intestine, brain, dental
pulp and elsewhere.
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19. Advantages of Embryonic Stem Cells
1. Flexible - have the potential to
make any cell.
2. Immortal –can provide an endless
supply of cells.
3. Availability - embryos from in vitro
fertilization clinics.

20. Disadvantages of Embryonic Stem Cells
1.
2.
3.
4.
Difficult to differentiate uniformly into a
target tissue.
Immunogenic - cells from a random
embryo donor may be rejected after
transplantation
Tumorigenic - capable of forming
tumors.
Destruction of developing human life.

21. Advantages of Adult Stem Cells
1.
2.
3.
4.
5.
6.
Adult stem cells from bone marrow and
umbilical cords appear to be as flexible.
Somewhat specialized.
Not immunogenic - recipients who receive
the products of their own stem cells will not
experience immune rejection.
Relative ease of procurement - some adult
stem cells are easy to harvest (skin, muscle,
marrow, fat)
Non-tumorigenic-tend not to form tumors.
No harm done to the donor.

22. Disadvantages of Adult stem cell
1. Limited quantity - can sometimes
be difficult to obtain in large numbers.
2. Finite - may not live as long as
embryonic stem cells in culture.
3. Less flexible - may be more
difficult to reprogram to form other
tissue types

23. Why are adult stem cells preferable
to embryonic stem cells?
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Adult stem cells are naturally exist in our
bodies, and they provide a natural repair
mechanism for many tissues.
They belong in the microenvironment of an
adult body, where they never cause tumors
and immune system reactions.
Adult stem cells have already been
successfully used in human therapies for
many years.
NO THERAPIES in humans have ever been
successfully carried out using embryonic
stem cells.

24. Superior features of ESCs
Embryonic stem cells are easier to
identify, isolate and harvest.
 They grow more quickly and easily in the
lab than adult stem cells.
 They can be more easily manipulated
(they are more plastic)
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25. Classification of stem cells
Stem cells can be classified by the extent to
which they can differentiate into various cell
types.
totipotent,
pluripotent,
multipotent,
unipotent stem cells

27. Totipotent stem cells
1.
2.
3.
The fertilized egg is said to be totipotent
from the Latin totus, meaning “entire”.
The very first cells of an embryo, being
the 'stem' of all future cells of the
organism.
It has the potential to generate all the
cells and tissues that make up an
embryo.

28. Pluripotent stem cells
Pluripotent stem cells
are descendants of the
totipotent stem cells of
the embryo.
These cells, which
develop about four
days after fertilization,
can differentiate into
any cell type, except
for totipotent stem cells
and the cells of the
placenta.

29. Pluripotent stem cells
The term pluripotent is used to denote the
cells derived from all three embryonic germ
layers mesoderm, endoderm, and ectoderm.
Pluripotent cells have the potential to give
rise to any type of specialized cell of the
human body.
“Pluri” is derived from the Latin plures means
several or many.

30. Multipotent stem cells
Multipotent stem cells
are descendents of
pluripotent stem cells.
For example,
hematopoietic stem
cells, which are found
primarily in the bone
marrow, give rise to all
of the cells found in the
blood, including red
blood cells, white blood
cells, and platelets.

31. Unipotent stem cell
Unipotent stem cell, a term that is usually
applied to a cell in adult organisms
differentiating along only one lineage.
"Uni" is derived from the Latin word unus,
which means one.
The adult stem cells in many differentiated
tissues are typically unipotent.

32. Progenitor cells
Progenitor cells (or unipotent stem
cells) can produce only one cell type.
For example, erythroid progenitor
cells differentiate into only red blood
cells.

33. Blood is made in the Bone MarrowBlood Cell Development

34. “Terminally differentiated" cells
At the end of the
long chain of cell
divisions are
"terminally
differentiated" cells,
such as a liver cell
or lung cell, which
are permanently
committed to
specific functions.

35. Adult stem cells
The adult stem cell is an undifferentiated
(unspecialized) cell that is found in a
differentiated (specialized) tissue;
it become specialized to yield all of the
specialized cell types of the tissue from
which it originated.
Adult stem cells are capable of selfrenewal for the lifetime of the organism.

36. Sources of Adult stem cells

37. Adult stem cells(ASC) or
somatic stem cells
Adult stem cells are undifferentiated cells.
They are found in small numbers in most adult
tissues.
They can also be extracted from umbilical cord
blood.
They are also called “somatic stem cells,”
They are multipotent in nature.
E.g. hematopoietic stem cells, which form all the
various cells in the blood.

38. Plasticity of Adult stem cells
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Stem cells from one tissue may be able to give
rise to cell types of a completely different tissue, a
phenomenon known as plasticity .
Examples of such plasticity include blood cells
becoming neurons, liver cells that can be made to
produce insulin, and hematopoietic stem cells that
can develop into heart muscle.

39. Plasticity of adult stem cells

40. Hematopoietic stem cells (HSC)
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Blood cells are formed from hematopoietic stem
cells (HSC) by a process known as hematopoiesis
HSCs are first formed in the embryonic yolk sac, then
migrate to the fetal liver and spleen.
Bone marrow becomes the major location of HSC
and continues this role throughout life
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HSC properties
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HSC are pluripotent - they can differentiate into a
number of different blood cell types, including
lymphocytes, granulocytes, monocytes, mast cells,
megakaryocytes, and erythrocytes
HSC are self-renewing - they can divide to replenish
themselves in their pluripotent (undifferentiated) state.
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41. Umbilical cord stem cells
Blood from the placenta and umbilical cord that
are left over after birth is a rich source of
hematopoietic stem cells.
These so-called umbilical cord stem cells have
been shown to be able to differentiate into bone
cells and neurons, as well as the cells lining the
inside of blood vessels.

42. Cord blood stem cells
The umbilical cord
and placenta are rich
sources of stem
cells.
Cord blood collection
is a safe, simple
procedure that poses
no risk to the mother
or newborn baby.

43. Cord blood stem cells
Cord blood stem cells can grow into blood
forming cells, immune system cells or other
types of cells.
Cord blood stem cells have been used to
treat 70 different diseases, including
leukemia, lymphoma, and inherited diseases.

44. Cord- blood banking
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Cord blood banks collect
and store the blood within
the umbilical cord and
placenta after the birth of a
baby.
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The stem cells are
separated from the rest of
the blood and stored frozen
in liquid nitrogen.
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There are 2 types of banks
i.e. public and family cord
blood banks.

45. Embryonic Stem Cells(ESC)
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Embryonic Stem Cells are derived from
embryos that develop from eggs that have been
fertilized in vitro.
Embryonic Stem Cells are never derived from
eggs fertilized inside of a woman's body.
Human Embryonic Stem Cells are derived are
typically four or five days old embryos.

46. Properties of Embryonic Stem Cells
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Derived from the inner cell mass of the blastocyst.
Capable of undergoing an unlimited number of
symmetrical divisions without differentiating (longterm self-renewal).
Exhibit full (diploid), normal complement of
chromosomes.
Pluripotent ES cells can give rise to differentiated
cell types that are derived from all three primary
germ layers of the embryo (endoderm, mesoderm,
and ectoderm).

47. Potential sources of
Human stem cells (HSC)
Aborted fetal tissue
excess embryos from fertility clinics
embryos created through in vitro fertilization
Asexually created embryos by a human somatic
cell nucleus transfer to an egg with its own
nucleus removed.
Other sources include umbilical cord blood and
bone marrow.

49. Stem cell therapy.
Numerous diseases and damaged organs could
potentially be treated with cell therapy.
Treatment of neural diseases such as
Parkinson's disease, Huntington’s disease and
Alzheimer's disease.
Repair or replace damaged neurons.
Repair of damaged organs such as the liver and
pancreas.
Treatments for AIDS.

50. Stem cell transplantation (SCT)/
Bone marrow transplantation (BMT).
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When a patient's bone marrow fails to produce
new blood cells, for whatever reason, he or she
will develop anemia, persistent infections and
bleeding problems.
In order to restore blood cell production a patient
may be given Stem cell transplantation (SCT) for
healthy stem cells.
Stem cell transplants are used to treat malignant
diseases, mainly leukemia, lymphoma or myeloma
which involve the bone marrow.

51. Cancer treatment
Intense chemotherapy damages a person’s
bone marrow.
A chemo-cancer patient is left vulnerable to
infection, anemia and bleeding because of
the depletion of fresh blood cells.
Transplanting bone marrow tissue into a
chemo-cancer patient may be carried out.

52. Skin tissue repair
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skin, is readily cultured to provide
replacement tissue for burns victims.
Healthy skin cells from the patient can be
grown rapidly in vitro to provide selfcompatible skin grafts.

54. Myocardial Regeneration
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Cardio-myocytes lose their ability to proliferate after
birth and so heart muscle fibers cannot regenerate.
Myocardial injury, such as myocardial infarction
(MI), heals by replacement of contractile heart
muscle fibers by fibrotic tissue scar, which not only
cannot participate in pumping of blood.
The implanted myoblastic cells have the ability to
restore function of damaged cardio- myocytes.
It is possible to treat patients with extensive
myocardial infarction by cell transplantation (CT).

56. Is Stem Cell Research Ethical?
Embryonic
Stem Cells - morally objectionable, because the
human embryo must be destroyed during harvest.
Embryonic Germ Cells - morally objectionable when
utilizing fetal tissue derived from elective abortions.
Umbilical Cord Stem Cells - morally acceptable, since the
umbilical cord is no longer required once the delivery has
been completed.
Placentally-derived Stem Cells - morally acceptable, since
the afterbirth is no longer required after the delivery has been
completed.
Adult Stem Cells - morally acceptable.

57. Summary
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The stem cells inside an embryo will eventually give
rise to every cell, organ and tissue in the fetus's
body.
Stem cells are unspecialized cells
Stem cells can divide and renew themselves for
long periods of time
Stem cells can divide and become specific
specialized cell types of the body
Stem cells can replace dying, old or damaged cells.

58. References
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Odorico, J.S., Kaufman, D.S., and Thomson, J.A.
(2001). Multilineage differentiation from human
embryonic stem cell lines. Stem Cells. 19, 193 -204.
Smith, A.G. (2001). Origins and properties of mouse
embryonic stem cells. Annu. Rev. Cell. Dev. Biol.
Thomson, J.A. and Marshall, V.S. (1998). Primate
embryonic stem cells. Curr. Top. Dev. Biol. 38, 133165.
Chandross, K.J. and Mezey, E. (2001). Plasticity of
adult bone marrow stem cells. Mattson, M.P. and
Van Zant, G. eds. (Greenwich, CT: JAI Press).
Slack, J.M. (2000). Stem cells in epithelial tissues.
Science. 287, 1431-1433.

59. References
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Dzierzak, E., Medvinsky, A., and de Bruijn, M. (1998).
Qualitative and quantitative aspects of
haematopoietic cell development in the mammalian
embryo. Immunol. Today. 19, 228-236.
MacKey, M.C. (2001). Cell kinetic status of
haematopoietic stem cells. Cell. Prolif. 34, 71-83.
J. A. Thomson, et al., 'Embryonic stem cell lines
derived from human blastocysts', Science, no. 5391,
vol. 282, November 1998, pp. 1145–7.
B. E. Reubinoff, M. F. Pera, C-Y Fong, A. Trounson
and A. Bongso, 'Embryonic stem cell lines from
human blastocysts: somatic differentiation in vitro',
Nature Biotechnology, vol. 18, pp. 399–404, 01 April
2000.

60. About the presenter
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Dr. B. Victor is a highly experienced postgraduate
professor, retired from the reputed educational institution St. Xavier’ s College(Autonomous), Palayamkottai, India627001.
He was the dean of sciences, assistant controller of
examinations and coordinator several academic research
workshops.
He has more than 32 years of teaching and research
experience
He has taught a diversity of courses and published 45
research articles in reputed national and international
journals.
Send your comments to : bonfiliusvictor@gmail.com

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