Stem cells are unspecialized cells that can differentiate into specialized cell types. There are several types of stem cells including embryonic, adult, and induced pluripotent stem cells. The document discusses the characteristics and types of stem cells in detail. It explains that embryonic stem cells are derived from early embryos and can differentiate into any cell type, while adult stem cells are found in tissues and can generate cell types of that tissue. The document provides examples of stem cell differentiation and potential medical uses for regenerative therapies.

1. Topic: Advances In Stem CellTopic: Advances In Stem Cell
ResearchResearch
Submitted By: M.Z.Arifeen.Submitted By: M.Z.Arifeen.
Submitted To: Dr. Aftab Ali ShahSubmitted To: Dr. Aftab Ali Shah
Student Of: M.Phil in BiotecnologyStudent Of: M.Phil in Biotecnology
University of MalakandUniversity of Malakand
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2. INTRODUCTION OF STEMINTRODUCTION OF STEM
CELL TECHNOLOGYCELL TECHNOLOGY

3. Stem Cell – DefinitionStem Cell – Definition
• A cell that has the ability toA cell that has the ability to
continuously divide and differentiatecontinuously divide and differentiate
(develop) into various other kind(s) of(develop) into various other kind(s) of
cells/tissuescells/tissues
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4. Stem Cell CharacteristicsStem Cell Characteristics
 ‘‘Blank cells’ (unspecialized)Blank cells’ (unspecialized)
 Capable of dividing and renewingCapable of dividing and renewing
themselves for long periods of timethemselves for long periods of time
(proliferation and renewal)(proliferation and renewal)
 Have the potential to give rise toHave the potential to give rise to
specialized cell types (differentiation)specialized cell types (differentiation)
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6. Kinds of Stem CellsKinds of Stem Cells
Stem cellStem cell
typetype DescriptionDescription ExamplesExamples
TotipotentTotipotent
Each cell can developEach cell can develop
into a new individualinto a new individual
Cells from early (1-Cells from early (1-
3 days) embryos3 days) embryos
PluripotentPluripotent
Cells can form any (overCells can form any (over
200) cell types200) cell types
Some cells ofSome cells of
blastocyst (5 to 14blastocyst (5 to 14
days)days)
MultipotentMultipotent
Cells differentiated, butCells differentiated, but
can form a number ofcan form a number of
other tissuesother tissues cells can
differentiate into a number of
cells, but only those of a closely
related family of cells
Fetal tissue, cordFetal tissue, cord
blood, and adultblood, and adult
stem cellsstem cells
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7. OligopotentOligopotent: stem cells can differentiate into only a few: stem cells can differentiate into only a few
cells, such as lymphoid or myeloid stem cellscells, such as lymphoid or myeloid stem cells
UnipotentUnipotent cells can produce only one cell type, theircells can produce only one cell type, their
own,own, but have the property of self-renewal, whichbut have the property of self-renewal, which
distinguishes them from non-stem cells (e.g., muscledistinguishes them from non-stem cells (e.g., muscle
stem cells).stem cells).
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8. Stem Cell DifferentiationStem Cell Differentiation
Princeton University
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9. This cellThis cell
Can form theCan form the
Embryo and placentaEmbryo and placenta
This cellThis cell
Can just form theCan just form the
embryoembryo
Fully matureFully mature 99

10. Kinds of Stem CellsKinds of Stem Cells
Embryonic stem cells come from a five to six-day-old embryo. They
have the ability to form virtually any type of cell found in the human
body.
Embryonic germ cells are derived from the part of a human embryo or
foetus that will ultimately produce eggs or sperm (gametes).
Adult stem cells are undifferentiated cells found among specialised or
differentiated cells in a tissue or organ after birth. Based on current
research they appear to have a more restricted ability to produce
different cell types and to self-renew.
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12. Blastocyst DiagramBlastocyst Diagram
Princeton University
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13. Sexual ReproductionSexual Reproduction
The Association of Reproductive Health Professionals
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14. Stages of EmbryogenesisStages of Embryogenesis
Day 1
Fertilized egg
Day 2
2-cell embryo Day 3-4
Multi-cell embryo
Day 5-6
BlastocystDay 11-14
Tissue Differentiation 1414

15. Derivation and Use ofDerivation and Use of
Embryonic Stem Cell LinesEmbryonic Stem Cell Lines
Isolate inner cell mass
(destroys embryo)
Heart muscleKidney
“Special sauce”
(largely unknown)
Day 5-6
Blastocyst
Inner cells
(forms fetus)
Outer cells
(forms placenta)
Heart
repaired
Culture cells
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16. Stages of EmbryogenesisStages of Embryogenesis
blastocystblastocyst Blastocyst inner mass cellsBlastocyst inner mass cells
8-cell stage8-cell stagecleavagecleavage
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19. An adult stem cell is thought to be anAn adult stem cell is thought to be an undifferentiatedundifferentiated cell,cell,
found among differentiated cells in a tissue or organ that can renewfound among differentiated cells in a tissue or organ that can renew
itself and can differentiate to yield some or all of the majoritself and can differentiate to yield some or all of the major
specialized cell types of the tissue or organ.specialized cell types of the tissue or organ.
The primary roles ofThe primary roles of adult stem cellsadult stem cells in a living organism are toin a living organism are to
maintain and repair the tissue in which they are found.maintain and repair the tissue in which they are found.
Scientists also use the termScientists also use the term somatic stem cellsomatic stem cell instead of adultinstead of adult
stem cell, where somatic refers to cells of the body (not the germstem cell, where somatic refers to cells of the body (not the germ
cells, sperm or eggs).cells, sperm or eggs).
What are adult stem cells?What are adult stem cells?
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20. If the differentiation of adult stem cells can be controlled in theIf the differentiation of adult stem cells can be controlled in the
laboratory, these cells may become the basis of transplantation-laboratory, these cells may become the basis of transplantation-
based therapies.based therapies.
The history of research on adult stem cells began about 60 yearsThe history of research on adult stem cells began about 60 years
ago. In the 1950s, researchers discovered that the bone marrowago. In the 1950s, researchers discovered that the bone marrow
contains at least two kinds of stem cells.contains at least two kinds of stem cells.
1.1.One population, calledOne population, called hematopoietic stem cellshematopoietic stem cells, forms all the, forms all the
types of blood cells in the body.types of blood cells in the body.
2.2.A second population, calledA second population, called bone marrow stromal stembone marrow stromal stem
cellscells (skeletal stem cells), These non-hematopoietic stem cells(skeletal stem cells), These non-hematopoietic stem cells
make up a small proportion of themake up a small proportion of the stromal cellstromal cell population in thepopulation in the
bone marrow, and can generate bone, cartilage, fat, cells thatbone marrow, and can generate bone, cartilage, fat, cells that
support the formation of blood, and fibrous connective tissue.support the formation of blood, and fibrous connective tissue.
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21. Where are adult stem cells found, andWhere are adult stem cells found, and
what do they normally do?what do they normally do?
Adult stem cells have been identified in many organs and tissues,Adult stem cells have been identified in many organs and tissues,
including brain, bone marrow, peripheral blood, blood vessels,including brain, bone marrow, peripheral blood, blood vessels,
skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium,skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium,
and testis.and testis.
They are thought to reside in a specific area of each tissueThey are thought to reside in a specific area of each tissue
called a "stem cell niche.called a "stem cell niche.
Stem cells remain non-dividing for long periods of time untilStem cells remain non-dividing for long periods of time until
they are activated by a normal need for more cells to maintainthey are activated by a normal need for more cells to maintain
tissues, or by disease or tissue injury.tissues, or by disease or tissue injury.
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22. Typically, there is a very small number of stem cells in eachTypically, there is a very small number of stem cells in each
tissue, and once removed from the body, their capacity to divide istissue, and once removed from the body, their capacity to divide is
limited, making generation of large quantities of stem cellslimited, making generation of large quantities of stem cells
difficult.difficult.
Scientists in many laboratories are trying to find better ways toScientists in many laboratories are trying to find better ways to
grow large quantities of adult stem cells ingrow large quantities of adult stem cells in cell culturecell culture and toand to
manipulate them to generate specific cell types so they can be usedmanipulate them to generate specific cell types so they can be used
to treat injury or disease.to treat injury or disease.
Some examples of potential treatments include regeneratingSome examples of potential treatments include regenerating
bone using cells derived from bone marrow stroma, developingbone using cells derived from bone marrow stroma, developing
insulin-producing cells for type 1 diabetes, and repairing damagedinsulin-producing cells for type 1 diabetes, and repairing damaged
heart muscle following a heart attack with cardiac muscle cells.heart muscle following a heart attack with cardiac muscle cells.
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23. AdultAdult stemstem cellscells
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25. scientists have reported that adult stem cells occur in manyscientists have reported that adult stem cells occur in many
tissues and that they enter normaltissues and that they enter normal differentiationdifferentiation pathways topathways to
form the specialized cell types of the tissue in which they reside.form the specialized cell types of the tissue in which they reside.
Normal differentiation pathways of adult stem cells:Normal differentiation pathways of adult stem cells:
In a living animal, adult stem cells are available to divide,In a living animal, adult stem cells are available to divide,
when needed, and can give rise to mature cell types that havewhen needed, and can give rise to mature cell types that have
characteristic shapes and specialized structures and functions ofcharacteristic shapes and specialized structures and functions of
a particular tissue.a particular tissue.
The following are examples of differentiation pathways ofThe following are examples of differentiation pathways of
adult stem cells that have been demonstratedadult stem cells that have been demonstrated in vitroin vitro oror in vivoin vivo..
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26. Hematopoietic stem cells give rise to all the types of blood cells:Hematopoietic stem cells give rise to all the types of blood cells:
red blood cells, B lymphocytes, T lymphocytes, natural killerred blood cells, B lymphocytes, T lymphocytes, natural killer
cells, neutrophils, basophils, eosinophils, monocytes, andcells, neutrophils, basophils, eosinophils, monocytes, and
macrophages.macrophages.
Mesenchymal stem cellsMesenchymal stem cells give rise to a variety of cell types:give rise to a variety of cell types:
bone cells (osteocytes), cartilage cells (chondrocytes), fat cellsbone cells (osteocytes), cartilage cells (chondrocytes), fat cells
(adipocytes), and other kinds of connective tissue cells such as(adipocytes), and other kinds of connective tissue cells such as
those in tendons.those in tendons.
Neural stem cellsNeural stem cells in the brain give rise to its three major cellin the brain give rise to its three major cell
types: nerve cells (neurons) and two categories of non-neuronaltypes: nerve cells (neurons) and two categories of non-neuronal
cells—astrocytes and oligodendrocytes.cells—astrocytes and oligodendrocytes.
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27. Epithelial stem cellsEpithelial stem cells in the lining of the digestive tractin the lining of the digestive tract
occur in deep crypts and give rise to several cell types:occur in deep crypts and give rise to several cell types:
absorptive cells, goblet cells, paneth cells, and enteroendocrineabsorptive cells, goblet cells, paneth cells, and enteroendocrine
cells.cells.
Skin stem cellsSkin stem cells occur in the basal layer of the epidermis andoccur in the basal layer of the epidermis and
at the base of hair follicles. The epidermal stem cells give rise toat the base of hair follicles. The epidermal stem cells give rise to
keratinocytes, which migrate to the surface of the skin and formkeratinocytes, which migrate to the surface of the skin and form
a protective layer. The follicular stem cells can give rise to botha protective layer. The follicular stem cells can give rise to both
the hair follicle and to the epidermis.the hair follicle and to the epidermis.
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30. The Promise of Stem CellsThe Promise of Stem Cells
potential application of stem cells is making cells and tissues forpotential application of stem cells is making cells and tissues for
medical therapiesmedical therapies
Today, donated organs and tissues are often used to replaceToday, donated organs and tissues are often used to replace
those that are diseased or destroyedthose that are diseased or destroyed
Unfortunately, the number of people needing a transplant farUnfortunately, the number of people needing a transplant far
exceeds the number of organs available for transplantationexceeds the number of organs available for transplantation
Pluripotent stem cells offer the possibility of a renewablePluripotent stem cells offer the possibility of a renewable
source of replacement cells and tissues to treat diseases,source of replacement cells and tissues to treat diseases,
conditions, and disabilities including Parkinson's disease,conditions, and disabilities including Parkinson's disease,
amyotrophic lateral sclerosis, spinal cord injury, burns, heartamyotrophic lateral sclerosis, spinal cord injury, burns, heart
disease, diabetes, and arthritis.disease, diabetes, and arthritis.
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31. ApplicationsApplications
 Disease
• Diabetes, Spinal
cord injury,
Parkinson’s
disease, heart
disease
 Genetic based
Disease
• Cystic fibrosis,
Huntington’s
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Somatic Stem Cell Therapy: Using a Bone MarrowSomatic Stem Cell Therapy: Using a Bone Marrow
Transplant to Cure LeukemiaTransplant to Cure Leukemia
Leukemia is a cancer of white blood cells, or leukocytes.Leukemia is a cancer of white blood cells, or leukocytes.
Like other blood cells, leukocytes develop from somatic stemLike other blood cells, leukocytes develop from somatic stem
cells. Mature leukocytes are released into the bloodstream, wherecells. Mature leukocytes are released into the bloodstream, where
they work to fight off infections in our bodies.they work to fight off infections in our bodies.
Leukemia results when leukocytes begin to grow and functionLeukemia results when leukocytes begin to grow and function
abnormally, becoming cancerousabnormally, becoming cancerous
Successful treatment for leukemia depends on getting rid of allSuccessful treatment for leukemia depends on getting rid of all
the abnormal leukocytes in the patient, allowing healthy ones tothe abnormal leukocytes in the patient, allowing healthy ones to
grow in their place. One way to do this is through chemotherapy,grow in their place. One way to do this is through chemotherapy,
which uses potent drugs to target and kill the abnormal cells.which uses potent drugs to target and kill the abnormal cells.
When chemotherapy alone can't eliminate them all, physiciansWhen chemotherapy alone can't eliminate them all, physicians
sometimes turn to bone marrow transplants.sometimes turn to bone marrow transplants.

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In a bone marrow transplant, the patient's bone marrow stem cellsIn a bone marrow transplant, the patient's bone marrow stem cells
are replaced with those from a healthy, matching donorare replaced with those from a healthy, matching donor
To do this, all of the patient's existing bone marrow andTo do this, all of the patient's existing bone marrow and
abnormal leukocytes are first killed using a combination ofabnormal leukocytes are first killed using a combination of
chemotherapy and radiation.chemotherapy and radiation.
Next, a sample of donor bone marrow containing healthy stemNext, a sample of donor bone marrow containing healthy stem
cells is introduced into the patient's bloodstream.cells is introduced into the patient's bloodstream.
If the transplant is successful, the stem cells will migrate intoIf the transplant is successful, the stem cells will migrate into
the patient's bone marrow and begin producing new, healthythe patient's bone marrow and begin producing new, healthy
leukocytes to replace the abnormal cells.leukocytes to replace the abnormal cells.

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Umbilical Cord Blood Stem CellsUmbilical Cord Blood Stem Cells
Newborn infants no longer need their umbilical cords, so theyNewborn infants no longer need their umbilical cords, so they
have traditionally been discarded as a by-product of the birthhave traditionally been discarded as a by-product of the birth
process. In recent years, however, the stem-cell–rich blood foundprocess. In recent years, however, the stem-cell–rich blood found
in the umbilical cord has proven useful in treating the same typesin the umbilical cord has proven useful in treating the same types
of health problems as those treated using bone marrow stem cellsof health problems as those treated using bone marrow stem cells
and PBSCs.and PBSCs.
Umbilical cord blood stem cell transplants are less prone toUmbilical cord blood stem cell transplants are less prone to
rejection than either bone marrow or peripheral blood stem cells.rejection than either bone marrow or peripheral blood stem cells.
This is probably because the cells have not yet developed theThis is probably because the cells have not yet developed the
features that can be recognized and attacked by the recipient'sfeatures that can be recognized and attacked by the recipient's
immune system. Also, because umbilical cord blood lacks well-immune system. Also, because umbilical cord blood lacks well-
developed immune cells, there is less chance that the transplanteddeveloped immune cells, there is less chance that the transplanted
cells will attack the recipient's body,cells will attack the recipient's body,

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46. Unknowns in StemUnknowns in Stem
Cell/Cloning ResearchCell/Cloning Research
• It is uncertain that humanIt is uncertain that human
embryonic stem cellsembryonic stem cells in vitroin vitro cancan
give rise to all the different cellgive rise to all the different cell
types of the adult body.types of the adult body.
• It is unknown if stem cellsIt is unknown if stem cells
culturedcultured in vitroin vitro (apart from the(apart from the
embryo) will function as the cellsembryo) will function as the cells
do when they are part of thedo when they are part of the
developing embryodeveloping embryo
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47. Challenges to StemChallenges to Stem
Cell/Cloning ResearchCell/Cloning Research
• Stem cells need to beStem cells need to be
differentiated to thedifferentiated to the
appropriate cell type(s)appropriate cell type(s)
beforebefore they can be usedthey can be used
clinically.clinically.
• Recently, abnormalities inRecently, abnormalities in
chromosome number andchromosome number and
structure were found instructure were found in
three human ESC lines.three human ESC lines.
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48. Challenges to StemChallenges to Stem
Cell/Cloning ResearchCell/Cloning Research
• Stem cell development or proliferationStem cell development or proliferation
must be controlled once placed intomust be controlled once placed into
patients.patients.
• Possibility of rejection of stem cellPossibility of rejection of stem cell
transplants as foreign tissues is very high.transplants as foreign tissues is very high.
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49. Challenges to StemChallenges to Stem
Cell/Cloning ResearchCell/Cloning Research
• Contamination by viruses, bacteria, fungi,Contamination by viruses, bacteria, fungi,
and Mycoplasma possible.and Mycoplasma possible.
• The use of mouse “feeder” cells to growThe use of mouse “feeder” cells to grow
ESC could result in problems due toESC could result in problems due to
xenotransplantation (complicating FDAxenotransplantation (complicating FDA
requirements for clinical use).requirements for clinical use).
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50. (Time 2.19.01)
ThanksThanks
5050
In case of anyIn case of any
question pleasequestion please
contact me atcontact me at
zain_bbt@yahoo.comzain_bbt@yahoo.com