This document defines stem cells and discusses their characteristics, sources, and functions. It makes three key points: 1. Stem cells are unspecialized cells that can renew themselves and differentiate into specialized cell types. They are classified based on their potency and sources as embryonic, adult, totipotent, pluripotent, and multipotent stem cells. 2. Stem cells have plasticity, meaning they can take on cell fates different from their tissue of origin. This is influenced by their microenvironment. 3. Stem cells work by maintaining an interaction with their niche, the surrounding differentiated cells that secrete factors influencing stem cell behavior like division, death, or differentiation. Loss or

1. Understanding Stem Cell
Abdurahman Laqif
Yuyun Rindiastuti
Department of Obstetrics and Gynecology Medical Faculty
of Sebelas Maret University
Dr. Moewardi General Hospital of Surakarta
Indonesia

2. Contents
• What is Stem cell (SC)
– Definition
– Microanatomy
– Characteristics
– Development phase of SC
• When
– Stem cell time line
• Why
– Plasticity/ differntiation
• Where
– Resource
– Work
• How
– Make SC
– Work in the tissue/ body

3. Definition
• Stem cells are unspecialized cells in the
human body that are capable of becoming
specialized cells, each with new
specialized cell functions.

4. Definition
• Progenitor cell ( Precursor cell): is
unspecialized or has partial characteristic
of specialized cell that is capable of
undergoing cell division and yielding two
specialized cells 2-Example is the myeloid
progenitor/precursor undergoing cell
division to yield two specialized cells,
a-A
neutrophil
b-A red blood
cell

5. Progenitor SC
Intermediate/ progenitor stem cell
• 1-Stem cells, in general, generate an
intermediate cell type or types before they
achieve their final differentiation.
• 2-The intermediate cell is called a precursor or
progenitor cell.
3-Progenitor or precursor cells in fetal or adult
tissues are partly differentiated cells that divide
and give rise to differentiated cells.
4-Such cells are usually regarded as
"committed" to differentiate along a particular
cellular developmental pathway

6. Stem cells and Progenitor cell

7. Microanatomy Image: Stem cell
Stem cell
stem cell colony

8. Characteristics
Stem cells have two important characteristics
that distinguish them from other types of cells.
• First, they are unspecialized cells that renew
themselves for long periods through cell division.
• The second is that under certain physiologic or
experimental conditions, they can be induced to
become cells with special functions such as the
beating cells of the heart muscle or the insulin
producing cells of the pancreas

9. What is a Stem Cell?
Somatic Cell Stem Cell
Two identical daughters Self-renewal Differentiate

10. Properties of stem cell:
• they are:
1. capable of dividing and renewing
themselves for long periods
2. they are unspecialized
3. and they can give rise to specialized cell
types

11. Sources of stem cells:
• Embryonic Stem Cells
• Adult Stem Cells
• Adult Stem Cells
• Adult Stem Cells

12. Sources of Embryonic Stem Cells
1. In Vitro Fertilization ( IVF)  Blastocyst
A human blastocyst,
which is produced
about 5 days after
fertilization, is smaller
than the period at
the end of this sentence.
NIH/Mr. J.Conaghan.
2. Nuclear Transfer (SCNT)

13. Somatic Cell Nuclear Transfer
DOLLY
1997
“Decisions”
not irreversible
Melissa Henriksen, PhD

14. Producing Embryonic Stem Cells Using
Nuclear Transfer Is Not the Same as
Reproductive Cloning
The use of nuclear transfer to develop disease-specific
stem cells can be called research
cloning, and the use of this technique for
personalized tissue transplants is sometimes
called therapeutic cloning. These terms must be
carefully distinguished from reproductive
cloning, in which the intent is to implant a
cloned embryo in a female’s womb and allow it
to develop fully into an individual.

15. Adult Stem Cells sources
- Bone Marrow Stem Cells
- Peripheral Blood Stem Cells
- Neuronal Stem Cells (from olfactory bulb, spinal cord)
- Muscle Stem Cells
- Liver Stem Cells
- Pancreatic Stem Cells
- Corneal Limbal Stem Cells
- Umbilical Cord Blood

17. Human Stem Cell Classification based on the
sources

18. SC classification based on differentiation
potency
The range of commitment options available to a cell
• Totipotent
Potency
• Pluripotent
• Multipotent
• Oligopotent
• Unipotent

20. SC classification based on differentiation
potency
• Totipotent Stem Cells: The master cells of the body that
contain all the genetic information needed to create all the cells
of the body and the placenta. Totipotent cells exist only in the
first three to four divisions of the fertilized egg and give rise to
the next stage of development — the pluripotent stem cells
• Pluripotent Stem Cells: Stem cells that can develop into all the
different cell types in the body except the placenta. They give rise to
mulitpotent and unipotent stem cells as the embryo develops.
• Multipotent Stem Cells: Stem cells that can give rise to a limited
number of other cell types. They are committed to becoming a
variety of cell types associated with specific functions or
organs/tissues (e.g., blood, heart, muscle) in the body. For example,
blood stem cells give rise to red blood cells, white blood cells, and
platelets
• Unipotent Stem Cells: Stem cells that can renew and give rise to
only a single mature cell type.

21. Potency
Pluripotent Multipotent

22. Stem cell plasticity
Different Cell Types
pancreatic bone neurons ES
Same DNA
Different Gene Expression

23. Plasticity of HESC
• Human embryonic stem cell (HESC) telah
terbukti sangat primitif, dapat berproliferasi
tanpa batas, dan memiliki kemampuan
untuk menurunkan galur semua jenis sel
dewasa.

24. Plasticity of ASC
• adult stem cell (ASC), dari jaringan dewasa yang
sudah terarah menjadi jaringan tertentu, masih
mampu berdiferensiasi menjadi sel bagian dari
suatu jaringan lain. Pada saat ini belum ada
istilah baku untuk menyebut fenomena ini dalam
literatur ilmiah. Maka sering disebut sebagai
plastisitas, diferensiasi unorthodox, maupun
transdiferensiasi.
• Tampaknya, dengan sinyal microenvironment,
yang sesuai, adult stem cell dari sumsum tulang
mampu bertransdiferensiasi menjadi berbagai
macam sel dari organ yang berbeda-beda.
Kirschstein R, Skirboll LR.

25. Plasticity of ASC
• 1. It is the ability of an adult stem cell from one
tissue to generate the cell type (s) of another
tissue.
2. Example under experimental conditions, adult
stem cells from bone marrow generated cells that
resemble neurons and other cell types are found in
the brain.
3. Evidence suggests that, adult stem cells
are capable of being "genetically reprogrammed”
to generate cells that have characteristics of
different tissues.
Dr. Fakhri Al-Bagdadi BVSc, Ph.D.

26. Development phase of SC
• Tidak diketahui asal muasal yang pasti dari adult
stemcell ; beberapa peneliti mengajukan
hipotesis bahwa stem cell yang dicegah untuk
berdiferensiasi ini disebar dan diletakkan
dengan mekanisme tertentu yang belum
diketahui selama periode perkembangan fetal.

27. of stem cell division: From SC to terminal diffferentiated

28. Why SC have plasticity capability?
• Kerusakan jaringan tampaknya menciptakan
lingkungan yang sesuai bagi perubahan
orientasi diferensiasi ini. Tampaknya lingkungan
jaringan extrahematopoietic yang terbentuk
setelah apoptosis atau nekrosis (seperti
keseimbangan sitokin maupun keadaan matriks
ekstraseluler) memungkinkan engraftment yang
sesuai bagi stem cell yang sedang beredar di
aliran darah. Yang tidak diketahui adalah
apakah stem cell melewati fase jaringan spesifik
sebelum maturasi, baik melalui transdiferensiasi
maupun fusi sel.

29. Plastisitas: Transdiferensiasi langsung dan
tak langsung
• Sel yang sudah terarah telah memulai rangkaian
diferensiasi terminal yang diduga disebabkan oleh
perubahan konformasi DNA. Transdiferensiasi
menunjukkan kemampuan dari sebuah sel yang sudah
terarah untuk mengubah pola ekspresi gennya menjadi
sel yang betul betul berbeda dengan karakter asalnya,
dan ini dapat terjadi langsung maupun tak langsung.
Transdiferensiasi tak langsung berarti stem cell berde-diferensiasi
diikuti proses maturasi ke jalur alternatif.
Transdiferensiasi langsung berarti terdapat transisi
langsung pada pola ekspresi gen sel tersebut.

30. Plastisitas : Fusi sel
• Mekanisme alternatif untuk plastisitas adalah
terjadinya fusi sel antara hematopoietic stem cell
dengan non-hematopoietic stem cell membentuk
heterokarion, dengan demikian mengubah pola
ekspresi gen dari pola asli sel sumsum tulang
menjadi pola ekspresi pasangan fusinya.
Contohnya, fusi in vitro fibroblast dengan
myoblast diketahui menghasilkan ekspresi
mRNA yang spesifik untuk myocyte dengan
nuklei yang spesifik untuk fibroblast.

31. When ?

32. How : Stem cell work?  Stem cell
Niche
• Both ES cells and somatic stem cells are thought to be maintained (and
perhaps defined) by the environment produced by the surrounding
differentiated cells.
• • Exactly how this stem cell niche is maintained is not known yet.
• • The differentiated cells may:
• – secret specific factors into the surrounding matrix
• – communicate with the stem cells via gap junctions or receptor mediated
inducers
• – Such communication may activate specific signaling pathways, such as the
Wnt/frizzled (which activates Lef-1/TCF), Notch/delta, or
• Sonic hedgehog/patched pathways.
• • Loss of the stem cell niche can induce a stem cell to divide, die, or
differentiate.
• • Change in the niche may induce a stem cell to alter its phenotype and its
function.

33. Stem cell Niche

34. Use