definition properties characteristics types maintainance cell proliferation in development and differentiation

1. BY
EMANI APARNA
I M PHARM
DEPT OF PHARMACOLOGY
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2. Adult stem cells are undifferentiated cells,
found throughout the body after
development, that multiply by cell division
to replenish dying cells and generate
damaged cells.
Somatic stem cells.
Adult stem cells is centered on its ability to
divide or self renew indefinitely and
generate all the cell types of the organ from
which they originate, potentially
regenerating the entire organ from a few
cells.
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4. Adult stem cells have been discovered in
many different types of organs and
tissues, and there are probably more, yet
to be discovered from researchers places,
where adult stem cells may reside. Some
of these tissues are:
 Blood vessels
 Bone marrow
 Gut
 Heart
 brain
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5.  Liver
 Ovarian epithelium
 Peripheral blood
 Skeletal muscle
 Skin teeth
 Testis
Usually ,only a very small number of stem
cells reside in a tissue/organ and they cant
be found throughout its in entirely. Instead
they usually reside in a very limited area of
that tissue or organ which is called as “stem
cell niche”
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6. Stem cells possess two properties:
 Self renewal: ability to go through numerous cycles of cell
division while still maintaining its undifferentiated state.
two types of cell division
1. systemic division
2. a systemic cell division
 Potency: refers to the ability of a stem cell to develop
into other cell types of specialized cells, for instance
neurons, platelets , muscle cells and epithelial cells.
Higher the number of distinct cell types a stem cell can
develop into, the higher its potency. Eg: hematopoietic
stem cells
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7. Any adult stem cell will have one of the following
degrees:
 MULTIPOTENT: Adult stem cells that can
differentiate into many cell types, that all
however belong to the same family! Eg:
hematopoietic stem cells
 OLIGOPOTENT: Adult stem cells that can only
differentiate into very limited number of very
closely related cells. For instance, vascular stem
cells have the capacity to become either
endothelial or smooth muscle cells
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8.  UNIPOTENT: Adult stem cells with the ability
to produce only one type of cell.
Their existence is still hypothesized, as a
true example of unipotent stem cell is yet to
be found
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10.  Hematopoietic stem cells: bone marrow and
gives rise to all blood types
 Mammary stem cells: growth of mammary
glands during puberty and gestation and play an
important role in carcinogenesis of the breast.
 Intestinal stem cells: divide continuously
throughout life and use a complex program to
produce the cells lining the surface of the small
and large intestine.
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11.  Endothelial stem cells: one of the three
types of multipotent stem cells found in the
bone marrow
 Mesenchymal stem cells: are of stromal
origin and may differentiate into variety of
tissues.
Isolated from placenta, adipose
tissue,lung,bone marrow and blood.
 Neural stem cells: stem cells in brain has
been postulated following the discovery that
the process of neurogenesis the birth of new
neurons ,continues into adulthood.
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12.  olfactory stem cells: multipotent stem cells,
found in the olfactory mucosa, the upper region
of the nasal cavity. They can develop into heart,
liver, kidney, brain and nerve cells.
 Skin stem cells: basal layer of the epidermis and
at the base of hair follicles. The have the
capacity to develop into keratinocytes.
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13. A Colombian female adult named Claudia castillo
whose trachea had collapsed due to tuberculosis.
Researchers have harvested a section of trachea
from a donor and stripped off the cells that could
cause an immune reaction ,leaving a grey trunk of
cartilage.
This section of trachea was then “ seeded “with
stem cells taken from Ms Castillo’s bone marrow and
a new section of trachea was grown in the laboratory
for four days.
The new section was then transplanted into the left
bronchus of the patient.
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14. Because stem cells were harvested from one own
bone marrow it was not necessary for her to be
given anti-rejection medication and when the
procedure was reported four months later the
patients immune system was showing no signs of
rejecting the transplant.
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15.  All tissues need essential basics in order to
grow and replicate.
 This support is provided by the connective
matrix which comprises connective tissue
and blood vessels, which provide nutrients,
oxygen and a waste removal service. These
vessels are made of specialized endothelial
cells.
 Tissues also need to communicate so as to
act in a co-ordinated manner.
 Nerve cells serve to allow communication
between tissues and signal actions
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16.  An essential step in tissue maintenance is
renewal of dead or damaged cells in a
manner which preserves the tissue integrity.
 Three major phenomena allow for this to
occur:
1.Cell signal their neighbors as to their state of
growth. If more cells are required due to
increased cell death, growth factors are
secreted to stimulate growth of that
particular cell.
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17. 2.secondly,tissue structure is maintained by
selective cell adhesion. Cells selectively attach
to their own kind, or to selective structural
components. These interactions are determined
by adhesion molecules on their cell membranes.
3.Thirdly,tissue identity is maintained by cell
memory at gene level. Once a cell has
differentiate to its final cell type, it divides to
produce more of same type. A liver cell will
divide to make more liver cells, a heart cell
more heart cells. This process ensures the
preservation of different tissue types in the
body.
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18. Early development is characterized by the rapid
proliferation of embryonic cells which then
differentiate to produce the many specialized types of
cells that make up the tissues and organs of
multicellular animals.
As cells differentiate, their rate of proliferation usually
decreases, and most cells in adult animals are arrested
in the Go stage of the cell cycle.
A few types of differentiated cells never divide again,
but most cells are able to resume proliferation as
required to replace cells that have been lost as a result
of injury or death.
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19. In addition, some cells divide
continuously throughout life to replace
cells that have a high rate of turnover in
adult animals.
Cell proliferation is thus carefully
balanced with cell death to maintain a
constant number of cells in adult tissues
and organs.
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20. stem cells divide to produce daughter
cells that can either differentiate or
remain as stem cells, thereby serving as a
source for the production of
differentiated cells throughout life.
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21. EG: Blood cell proliferation
 Erythrocytes
 Granulocytes
 Platelets
 Lymphocytes
Life span-few days to months.
Continually produced by the division of a
common stem cell in the bone marrow.
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23. Descendants of the pluripotent stem cell
then become committed to specific
differentiation pathways.
These cells continue to proliferate and
undergo several rounds of division as they
differentiate.
Once they become fully
differentiated,however,they cease
proliferation, so the maintenance of
differentiated blood cell populations is
dependant on continual proliferation of the
pluripotent stem cell.
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24.  Leukemia and related bone/blood cancers
bone marrow utilizing bone marrow
transplants.
 Diseases such as liver cirrhosis, spinal
cord injury, pheripheral vascular disease.
 Used in treatment of: diabetics
 Rheumatoid arthritis
 Parkinsonism disease
 Osteoarthritis
 Alzheimers disease
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25.  Baldness
 Learning defects
 Anti-cancer
 Heart infarction
 Replace missing teeth
 Repair hearing
 Restore vision
 Wound healing
 Crohn disease
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Jeevan blood bank and
research center, Chennai
Relicord ,Navi Mumbai
Baby Cell, Mumbai
All over India
Karnataka

27.  stem cells wikipedia
 stem cells freak
 www.stemcell.childrenhospital.org
 www.stemcell.nih.gov
 www.stemcellindia.org
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