stem cells

Question 1

4LEARNING OUTCOMES

Answer 1

• Define what stem cells are
• Classify the different stem cell types
• Describe how stem cells can be used therapeutically
• Discuss current limitations for stem cell therapies

Question 2

what are stem cells

Answer 2

are self-renewing and able to differentiate into all type of cells

Question 3

what is the origin of stem cells

Answer 3

blastula which form human embryonic stem cells

Question 4

what are the classification of stem cells

Answer 4

they are classified according to their ability to produce
-totipotent: stem cells that can produce a whole organism
-pluripotent: stem cells that can produce all 3 germ layers
-multipotent (mature stem cell): only produce tissue specific cell line.

Question 5

what are the embryonic stem cells (ES) and their function

Answer 5

ES are isolated from the fertilized eggs.
f(x):
- give rise to all three germ layers, ES can be converted into the neurons, blood cells, and liver cells.
- in vitro study for development process which can’t be assessed otherwise.
- used in cell therapy for the transplant of cells of interest differentiated from ES cells into patients

Question 6

what are the ES cells limitation

Answer 6

• allogeneic transplant can lead to immune rejection due to unmatched human leukocytes antigen
• ethical concern about the human blastocysts

Question 7

how to solve the immune rejection of ES cells

Answer 7

-bio-banking: which is the production of an ES cell bank with ES cell line derived from HLA that are commonly found in population
- production ES cells from patients themselves
-somatic cell nuclear transfer

Question 8

how does somatic cell nuclear transfer done

Answer 8

• isolate nucleus of patient’s cells and inject it into an unfertilized egg
• then development of cloned embryo, ehich have the same antigen haplotype and can be used to isolate ES cells

Question 9

can mature somatic cells programmed to become pluripotent stem cell

Answer 9

yes

Question 10

what is the problem with therapeutic cloning

Answer 10

insufficient source of embryo oocytes because there is need of more than one egg per patient to have successful injection of nucleus

Question 11

how can we solve the above problem of embryo oocyte source

Answer 11

we can use pluripotent stem cells (IPS cells).
means now we can do stem cell therapy based on the IPS cells

Question 12

how does IPS cells formed

Answer 12

fully differentiated somatic cells can be programmed to pluripotent stem cells with introduction of special pluripotent genes via viral transduction

Question 13

what is IPS cell and their potential

Answer 13

• all the f(x) of stem cells including: transplant, give rise to all three germ layers, in vitro study of development
• no ethical issue because no need for the embryos
• are vastly renewable, cell number is not a limitation
• easy accessible/ less expensive
  -non-immunogenic

Question 14

what are the cons of IPS

Answer 14

• problem of transplanting incomplete differentiated cells
  -personal medication is not possible means is time consuming and not patient friendly
  -tumorigenicity

Question 15

what are Multipotent stem cells

Answer 15

adult stem cells that are tissue specific or that only produce specific cell line

Question 16

what is the cons of multipotent stem cells

Answer 16

they are hard to isolate and access

Question 17

what are Hematopoietic stem cells (HSCS)

Answer 17

are blood stem cells that are in process of producing blood cells

Question 18

which cell that are mostly used during stem cells transplant

Answer 18

HSCS

Question 19

• describe allogeneic HSC transplantation ad give the diseases

Answer 19

1. stem cells are collected from donor
2. stem cells are infusion into patient without immune system: here first destroy the patient leukemia cells and immune system
3. rebuild of immune system with donor cell, give patient with new hematopoietic system

diseases: leukemia

Question 20

what are Mesenchymal stem cells (MSCS)

Answer 20

they can differentiate into the osteocytes, chondrocytes and adipocytes

Question 21

what are the pros of MSCS

Answer 21

• immunosuppression property
• short-term existence means is allogeneic safe
• anti-inflammation properties

Question 22

What do we need to consider when taking a stem cell therapy to the clinic?

Answer 22

• scarcity of stem cells: know the source,HSC ex-vivo
• design protocol to obtain cell of interest from stem cells: ensure complete differentiation of all pluripotent stem cells, make sure the cell of interest are obtainedblood formation during development
• safety of material to be transplanted
• how to efficiently deliver the cells: transdifferentiation, bioengineering

Question 23

Pluripotent stem cells can give rise to neural stem cells.

Answer 23

yes

Question 24

ESCs and iPSCs are equivalent for
transplantations as part of stem cell
therapies.

Answer 24

no, because they can lead to ethical problem, tumorigenicity, immunogenicity

Question 25

Umbilical cord blood derived stem cells can be
used for clinical applications directly

Answer 25

no, because number are not enough/ insufficient source

Question 26

Induced pluripotent stem cells pose no
concern of immune rejection.

Answer 26

false, even if IPS cells derived from patient blood but they can pose risks of genomic and epigenetic alterations

Question 27

Guided differentiation of induced pluripotent
stem cells into blood cells in a lab setting can
be used for clinical applications.

Answer 27

yes, because is now in trial