This presentation provides an overview of stem cells and regenerative medicine with a focus on induced pluripotent stem cells (iPSCs). It includes definitions of key stem cell concepts and types. There are two main activities for students: 1) A general activity to familiarize students with stem cell concepts; and 2) A case study examining the genetic modification of iPSC-derived macrophages and their potential applications. The presentation aims to engage students and deepen their knowledge of this field.
2. 2
This presentation was developed by Martha Lopez Yrigoyen.
It is intended as a flexible tool for lectures and tutorials for first year students in the
Biological and Biomedical Sciences. Diagrams are also encouraged to be used by
scientists, science communicators and educators.
Not all slides will be useful for everyone or for every occasion. Slides can be
adapted for the purpose needed.
There are two main activities intended for undergraduate students to engage and
deepen their knowledge in the field of stem cells. The first activity is more general
and its aim is to familiarize students with the core concepts in stem cell and
regenerative medicine. The second activity is a novel and current example of how
induced pluripotent stem cells are being used in cutting edge biomedical research.
The two publications suggested for students to read can be swapped for other
examples.
Presentation is licensed under a Creative Commons Attribution License 4.0
https://creativecommons.org/licenses/by/4.0/
Notes on this presentation
by Martha Lopez Yrigoyen
University of Edinburgh
5. Self renewal
Maintains the
stem cell pool Differentiation
Replaces dead or
damaged specialized
cells throughout life
Why do Stem Cells self-renew and
differentiate?
5
6. What is ‘Pluripotency’?
o Totipotent: Capable of forming the entire organism,
including extra-embryonic tissues
o Pluripotent: Capable of forming every cell type in an
organism, including germ cells
o Multipotent: Capable of forming multiple lineages
comprising one or more entire tissues
o Oligopotent: Capable of forming two or more
lineages, within a tissue
o Unipotent: Capable of forming a single lineage within
a tissue
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7. Types of Stem Cells
Embryonic stem cells
(ESCs)
Found in the blastocyst (very
early stage embryo that has
about 50 to 100 cells) Tissue stem cells
Found in different tissues
during fetus, baby and
adult stages Induced Pluripotent
Stem Cells (iPSCs)
Re-programmed cells
Peripheral blood
cells
Fibroblasts
OCT4 SOX2 C-MYC KLF4
Reprogramming
iPSCs
7
8. Outer layer of cells
= ‘Trophectoderm’ Placenta
Inner cell mass (ICM)
Blastocyst
ESCs taken from the
ICM
ESCs in Culture
(They can be
expanded and
differentiated)
Human Blastocyst (2007)
Mr. J Conaghan (for NIH),
Public Domain
CC0
8
Embryonic stem cells (ESCs)
9. ESCs in Culture
Mesoderm
Endoderm
Ectoderm
3 germ layers
9
Brain, spinal cord, nerve
cells, hair, skin, teeth,
sensory cells of eyes,
ears, nose, and mouth,
pigment cells.
muscles, blood, blood
vessels, connective
tissues, heart
gut (pancreas,
stomach, liver), lungs,
bladder, germ cells
(eggs or sperm)
Differentiation of ESCs
10. 10
Activity 1
1. What do Embryonic Stem Cells look like under
the microscope?
2. What are some of the ethical implications of
using ESCs?
3. What techniques are used to genetically modify
ESCs?
4. What is a chimeric mouse?
12. differentiation
Differentiation into specialized blood
cells:
red blood cells, white blood cells
(macrophages, neutrophils, dendritic
cells, etc.), platelets
12
Tissue Stem Cells
nerating Red Blood Cells in the lab
ody Lab-produced cells
roduce a central Can we improve the yield of red blood
ms to solve Rationale
PhD Project
vs.
xx
Haematopoietic stem cells
HSCs
(Multipotent)
13. Haematopoietic stem cells (HSCs)
HSC
13
nerating Red Blood Cells in the lab
body Lab-produced cells
produce a central
e macrophage?
Can we improve the yield of red blood
cells with no nucleus?
ems to solve Rationale
PhD Project
2
vs.
x
x
Bone
Marrow
Self-renew
Committed progenitors Specialized cells
NK Cell
T-Cell
B-Cell
Dendritic cell
Basophil
Eosinophil
Neutrophil
Monocyte Macrophage
Erythrocyte
Megakaryocyte Platelet
14. 14
Peripheral blood
cells
Fibroblasts
OCT4 SOX2 C-MYC KLF4
Reprogramming
iPSCs
iPSCs behave like ESCs
They circumvent the ethical
implications!
Shinya Yamanaka received the Nobel
Prize in 2012 for the discovery that
specialized cells can be
reprogrammed into pluripotent cells
Ulla Montan, 2012
CC-BY –SA 4.0
No changes made
https://commons.wikimedia.org/wiki/File:Yamanaka.jpg
License
https://creativecommons.org/licenses/by-sa/4.0/deed.en
Induced Pluripotent Stem Cells (iPSCs)
16. Drug Testing Cell-Therapy In vitro models of
health and
disease
Human iPSCs and their genetic manipulation
provide a valuable tool
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17. A case study… Genetically modified iPSC
derived macrophages
17
Macrophages are white blood cells that are:
• Difficult to genetically manipulate
• Prone to silencing of exogenous genes
• Heterogeneous on phenotype and very plastic (they change
phenotype upon slight changes in environmental cues)
Genetic manipulation of iPSCs and their differentiation
to macrophages represents a tool to modulate/stabilise
macrophage phenotype
18. 18
Activity 2
Please read the following open-access articles:
Lopez-Yrigoyen M et al. 2018. ‘A human iPSC line capable of
differentiating into functional macrophages expressing ZsGreen: a tool for
the study and in vivo tracking of therapeutic cells’. Phil. Trans. R. Soc. B
373: 20170219.
http://dx.doi.org/10.1098/rstb.2017.0219
License
https://creativecommons.org/licenses/by/4.0/
Lopez-Yrigoyen M et al. 2019 ‘ Genetic Programming of macrophages
generates an in vitro model for the human erythroid island niche’. Nature
Communications 10:881
https://doi.org/10.1038/s41467-019-08705-0
License
https://creativecommons.org/licenses/by/4.0/
19. Questions to answer:
1. What are the advantages of iPSC derived
macrophages vs. peripheral blood derived
macrophages and vs. immortalised lines derived
macrophages?
2. What is a safe harbour locus?
3. How are iPSCs differentiated into macrophages?
4. What is a transcription factor? How are the authors
claiming to ‘program’ iPSC macrophages?
5. KLF1 activation in macrophages supports erythroid
maturation and enucleation… How?
19