Stem Cell Engineering Flashcards
embryonic stem cells have the ability to differentiate into a wide range of cells provided?
the right environment in culture
can divide indefinitely
unlike a zygote, ES cells can
generate an actual organism
es cells are derived from ? and when put back in same place/time ?
inner cell mass of blastula
when put back they can re-integrate perfectly
teratoma formation
when injecting es cells into an embryo at a later stage or into an adult
they fail to receive proper signals for differentiation
and form teratomas
define teratoma
cell mass w/ no axis of formation or organization/segmentation
list 3 uses of es cells
- study disease mechanisms
- test chemicals/drugs
- derive from patients to create customized treatments
SCeNT
somatic cell nuclear transfer
combining a somatic cell nucleus and an oocyte
stages of development
fertilization zygote blastocyst w/ ICM gastrula - 3 levels fetus
es cells must be derived from the ____ stage, once an embryo reaches _____ you can no longer use the cells.
blastocyst
gastrula stem cells are not useable
signals for differentiation - adipocytes
1st retinoic acid
2nd - insulin and thyroid hormone
signals for differentiation - neurons
- retinoic acid
signals for differentiation - macrophages
- MC SF + interleukin-3 + interleukin-1
signals for differentiation - smooth muscle cells
- dibutyrl cAMP + retinoic acid
signals for differentiation - glial cells
- fibroblast gf
- fibroblast gf2 + epidermal gf
- fibroblast gf2 + platelet derived gf
SCeNT methods
- nucleus taken from somatic cell of patient
- inject it into oocyte
- blastocyst generated from hybrid
- es cells isolated from icm
- culture cells
example of SCeNT for clinical therapy
used for type I diabetes
injected into pancreas and new pancreatic cells are created
issues w/ SCeNT
- insufficient # of eggs
2. technically challenging - no trained people or proper equipment
____ genes have been found in ES cells that are not present in adult somatic cells. thus suggesting we may be able to ?
24 genes
reprogram adult cells into es-like cells
the key determinants of es cell character is ?
4 gene regulatory proteins Oct4 Sox2 Kif4 Myc
when the gene regulatory proteins are injected into fibroblasts they ?
form es-like cells
w/ the ability to differentiate into other cell types
what is the major issue w/ reprogramming adult cells
yield is low
~1-5% of cells injected turn into es-like stem cells
iPS cells
induced pluripotent cells
exposing somatic cells to transcription factors – genes for stem-ness
Myc seems to be involved directly in ?
up regulation of cell proliferation and
loosening of chromatic structures
stem cells taken from umbilical cords are
pluripotent
repair of skin using stem cells
burn victims
- -take epidermis stem cells from another area
- -culture them
- -give back to patient
- -skin will regenerate
while a burn victim is waiting for her stem cells to culture - what is does w/ the wound?
takes few weeks to culture cells
patient is given artificial skin in mean time
what occurs while a burn victim has their intermediate skin
fibroblasts and capillaries migrate towards artificial skin and reform underlying CT
after a burn victim has regenerated new skin, what does not come back?
hair
sebaceous glands
