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UNDERSTANDING STEM CELLS
By- Sayee Jadhav
Presentation Overview
1. What are stem cells?
2. What makes a cell a stem cell?
3. Types of stem cells
4. Stem cell timeline
5. Generation of stem cell lines in the laboratory
6. Major uses of stem cells
7. The promise of stem cells research
8. Are the promises of stem cells realistic?
9. Ethical and moral issues
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Concept of Stem cell
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What makes a cell a stem cell?
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Self renewing
Gives rise to mature, specialized cells
Long-term self renewal
Unspecialized: Pleuripotent or multipotent
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Types of stem cells
1. Based on ability to regenerate
Stem cell type
Description
Examples
Totipotent
Ability to differentiate into
all possible cell types, even
form a complete human
Cells from early (1-2
days) embryos
Pleuripotent
Ability to differentiate into
almost all cell types, but
cannot form a complete
human
Embryonic stem cells and
cells derived from
mesoderm, endoderm,
and ectoderm germ layers
Multipotent
Ability to differentiate into a Hematopoietic stem cells
closely related family of
that can become red and
cells
white blood cells or
platelets
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Types of stem cells
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Types of stem cells
2. Based on source of stem cells
Embryonic stem cells
￭ Source: Present in umbilical cord or
placenta of newborn
￭ Relatively easy to identify, isolate,
grow, and maintain in laboratory
￭ Risk of creating teratomas (tumors)
from implanting undifferentiated stem
cells
￭ Ethical concerns due to destruction
of blastocyst
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Types of stem cells
Adult stem cells
￭ Source: Bone marrow, spleen,
peripheral blood, fat (in liposuction)
￭ Difficult to identify, isolate, grow,
and maintain in laboratory
￭ Produce limited no. of cell types
￭ No major ethical issues have been
raised
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Stem cell timeline
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1956- First successful bone marrow transplant
1998- The first human embryonic stem cells are
isolated
2002- Pancreatic cells derived from mouse
embryonic stem cells cure diabetes in mice
2004- The type of nerve cell lost in Parkinson’s
disease is produced from human embryonic
stem cells
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Generation of stem cell lines
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Major use of stem cells
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Bone marrow transplantation
Autologous procedure
Allogenic procedure
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Major use of stem cells
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Neurological disorder
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The promise of stem cell research
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Are the promises of stem cells realistic?
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The basic research needed to develop viable
therapeutic options is a lengthy process that may
extend over many years and decades.
Legal issues that will affect stem cell applications
include how to address intellectual property concerns
and how to apply and enforce diverse and sometimes
conflicting state and national laws.
Social issues include concerns about the destruction
of embryos, the distribution of the benefits of the
research, and the protection of both physical and
privacy interests of egg and sperm donors and
clinical research subjects.
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Ethical and moral issues
1.
Is an embryo a person?
￭ Embryonic stem cell research uses
removing inner cell mass from excess
blastocysts in IVF treatment.
￭ This prevents the blastocysts from
continuing to develop into a human
being.
￭ Some religious groups believe that
life of human begins at conception,
thus opposing stem cell research.
￭ Some groups believe that embryo
gains a moral value of a human being
only after a few weeks of development
(fetus).
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Ethical and moral issues
Relationship of stem cell research to
reproductive cloning: Nuclear transfer
“Human reproductive
cloning should not now
be practiced. It is
dangerous and likely to
fail.”
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￭ Scientists use nuclear transfer,
create blastocyst, remove inner cell
mass from them, which is further
used to create stem cell lines.
￭ Reproductive cloning uses nuclear
transfer, create blastocyst, which is
then implanted into the uterus and
allowed to develop fully.
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Ethical and moral issues
3.
The ethics of human-animal chimera
￭ Chimeras are organisms composed
of cells or tissues from more than one
individual.
￭ Chimeras considered essential in
research, since no therapy can be
tested on humans without first testing
on animals.
￭ Creation of chimeras morally
acceptable as long as the chimera has
no sense of human consciousness
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Questions?
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THANK YOU
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