Trends in stem cel biology
Inhoudsopgave
Lecture 1 introduction of the course and ethics ................................................................................................ 1
Lecture 3 Epigenetics and pluripotency in mouse embryonic stem cells ........................................................... 3
Lecture 4 Reprogramming to induced pluripotency ........................................................................................ 12
Lecture 5 hematopoietic stem cells ................................................................................................................ 21
Lecture 6 stem cells in neurobiology .............................................................................................................. 29
Lecture 7 Epidermal stem cells in treatment .................................................................................................. 39
Lecture 1 introduction of the course and ethics
Note: This lecture will not be in the exam
Subjectivism in ethics
Ethical subjectivism: the idea that moral opinions are based on our own feelings and nothing
more. On this view, there is no such thing as ‘objective’ right and wrong.
Consequentialism: the rightness/ wrongness of an action is determined by its consequences.
Different forms of consequentialism:
- Utilitarianism: the action is the one that promotes the greatest happiness of the
greatest number (maximizes social utility).
- Ethical egoism: The right action is the one that promotes the greatest happiness of
the agent (maximizes the agent’s utility).
Deontology: the rightness/ wrongness of an action is determined by inherent features of the
action itself, or by an inherently valid rule.
If an action is of the wrong kind, it is forbidden, no matter how good its consequences are.
This rejects both utilitarianism and ethical egoism.
Kantianism: right actions must be universalizable and must trat rational agents as ends, not
mere means (trade-offs forbidden).
Universalizability: must be possible to will the principle of your action for everybody without
inconsistency. Lying violates universalizability because lying presupposes and exploits a
general practice of telling the truth.
End, not mere means: don’t treat rational agents (others or yourself) as mere objects to be
used or exploited. Personhood is the basis of ethical value and can’t be subordinated to
other values. Mustn’t sacrifice the few even to benefit many.
,Virtue ethics: The rightness/ wrongness of an action is determined by the character traits it
expresses.
,Lecture 3 Epigenetics and pluripotency in mouse embryonic stem cells
Learning goals
- Different forms of cell potency during development in vivo.
- Different types of mouse pluripotent cells in vitro (one of the ES cells). How is
pluripotency to be tested?
- Application of ES cells.
- Molecular mechanisms to maintain pluripotency.
- Pluripotency and chromatin structure.
What are stem cells?
Stem cells are biological cells that can differentiate into other types of cells and can divide to
produce more of the same type of stem cells (self-renewal).
Embryonic stem cells have the capacity to grow from one cell to for example a whole organ.
Mouse embryonic development: loss of potency
First divisions after fertilization
ICM stage already contains two defined, irreversible cell populations.
Late blastocyst three cell sub-populations:
- the trophectoderm (green)
- the inner cells mass (orange)
- the primitive endoderm (yellow).
In the blastocyst stage three axes can be defined: the embryonic-abembryonic (abemb-emb);
the animal-vegetal (an-veg); and a third axis on the same plane but perpendicular to the an-
veg axis.
, Further development (gastrulation) and full mouse
The inner cell mass will form the different germ layers during gastrulation.
Germ layers (2nd lineage decision):
- ectoderm
- endoderm
- mesoderm
During further differentiation, all +/- 200 cell types emerge.
e.g. ectoderm cells cannot become endoderm cells anymore, so they lost potency (they went
in a certain direction). The same accounts for when the ectoderm cells start differentiating in
for example neural tissue, these cells will lose potency. They cannot become another cell
type anymore.
In a dish with iPSCs you can do it, but it is very artificial.
Inhoudsopgave
Lecture 1 introduction of the course and ethics ................................................................................................ 1
Lecture 3 Epigenetics and pluripotency in mouse embryonic stem cells ........................................................... 3
Lecture 4 Reprogramming to induced pluripotency ........................................................................................ 12
Lecture 5 hematopoietic stem cells ................................................................................................................ 21
Lecture 6 stem cells in neurobiology .............................................................................................................. 29
Lecture 7 Epidermal stem cells in treatment .................................................................................................. 39
Lecture 1 introduction of the course and ethics
Note: This lecture will not be in the exam
Subjectivism in ethics
Ethical subjectivism: the idea that moral opinions are based on our own feelings and nothing
more. On this view, there is no such thing as ‘objective’ right and wrong.
Consequentialism: the rightness/ wrongness of an action is determined by its consequences.
Different forms of consequentialism:
- Utilitarianism: the action is the one that promotes the greatest happiness of the
greatest number (maximizes social utility).
- Ethical egoism: The right action is the one that promotes the greatest happiness of
the agent (maximizes the agent’s utility).
Deontology: the rightness/ wrongness of an action is determined by inherent features of the
action itself, or by an inherently valid rule.
If an action is of the wrong kind, it is forbidden, no matter how good its consequences are.
This rejects both utilitarianism and ethical egoism.
Kantianism: right actions must be universalizable and must trat rational agents as ends, not
mere means (trade-offs forbidden).
Universalizability: must be possible to will the principle of your action for everybody without
inconsistency. Lying violates universalizability because lying presupposes and exploits a
general practice of telling the truth.
End, not mere means: don’t treat rational agents (others or yourself) as mere objects to be
used or exploited. Personhood is the basis of ethical value and can’t be subordinated to
other values. Mustn’t sacrifice the few even to benefit many.
,Virtue ethics: The rightness/ wrongness of an action is determined by the character traits it
expresses.
,Lecture 3 Epigenetics and pluripotency in mouse embryonic stem cells
Learning goals
- Different forms of cell potency during development in vivo.
- Different types of mouse pluripotent cells in vitro (one of the ES cells). How is
pluripotency to be tested?
- Application of ES cells.
- Molecular mechanisms to maintain pluripotency.
- Pluripotency and chromatin structure.
What are stem cells?
Stem cells are biological cells that can differentiate into other types of cells and can divide to
produce more of the same type of stem cells (self-renewal).
Embryonic stem cells have the capacity to grow from one cell to for example a whole organ.
Mouse embryonic development: loss of potency
First divisions after fertilization
ICM stage already contains two defined, irreversible cell populations.
Late blastocyst three cell sub-populations:
- the trophectoderm (green)
- the inner cells mass (orange)
- the primitive endoderm (yellow).
In the blastocyst stage three axes can be defined: the embryonic-abembryonic (abemb-emb);
the animal-vegetal (an-veg); and a third axis on the same plane but perpendicular to the an-
veg axis.
, Further development (gastrulation) and full mouse
The inner cell mass will form the different germ layers during gastrulation.
Germ layers (2nd lineage decision):
- ectoderm
- endoderm
- mesoderm
During further differentiation, all +/- 200 cell types emerge.
e.g. ectoderm cells cannot become endoderm cells anymore, so they lost potency (they went
in a certain direction). The same accounts for when the ectoderm cells start differentiating in
for example neural tissue, these cells will lose potency. They cannot become another cell
type anymore.
In a dish with iPSCs you can do it, but it is very artificial.
