lecture 6 stem cells Flashcards
properties of stem cells
- unlimited self renewal
2. differentiation. into different cell types
type of potency that can change into embryonic and extraembryonic cell types
totipotent
totipotent stem cells are found
early embryos 1-3 days
cells that can change into endoderm, mesoderm or ectoderm
pluripotent
pluripotent stem cells are found in
Inner cell mass of blastocyst 5-14 days
type of potency that a cell can change into a limited number of things based on where it was taken
unipotent or multipotent
unipotent stem cells are found in
adult stem cells
two major types of stem cells
embryonic stem cells, adult stem cells
why cant we use embryonic stem cell
crazy prolife people
also have issues with non-autologous- rejection
when you use a patient’s own stem cells
autologous
when you use cells from others, familiar
allogeneic
use stem cells from different species
xenogeneic
iPS stands for
inducible pluripotent stem cells
explain iPS
inducible pluripotent stem cells
take adult cell from person, reverse it into stem cells and then make it into any type of cell
uses Oct4, Sox2, Klf4 and c-Myc
or uses virus to reverse
- could be used for regenerative medicine
- mostly used for disease modeling/ drug development
who discovered iPS process
Yamanaka 2012 noble prize
issues with iPS
c-Myc might lead to cancer, viruses might lead to issues down the line
explain adult stem cells
all tissues have their own stem cells
issue is finding, isolating and keeping the stem cells alive.
if you can keep them alive they can be used to regrow tissue and put back into patient
common adult stem cells
bone marrow, skin stem cells, corneal stem cells, mesenchymal stem cells
name a disease that bone marrow transplant helps
hodgkin lymphoma
explain how to use umbilical cord stem cells
stem cells are stored in placenta and umbilical cord, can be harvested and saved at birth- very expensive
then can be used later in life if needed
leukemia, fanconi anaemia
neighboring cells that help maintain stem cells
niche
example of niche cells
macrophage and mammary stem cells via Notch ligand DII1
SCNT
somatic cell nuclear transfer
explain SCNT
cloning
take egg, remove nucleus of egg, replace with somatic cell from somewhere else. egg will make whole new organism
Dolly
what are some issues with SCNT
expensive, aging problem- telomeres same length of cell where it was taken. personality not transferred
why use a pig
closer to humans then mice. iPS cells are used to study artherosclerosis- heart disease
explain how iPS can be used in horses
could use iPS to turn into osteoblasts that would make new bone and help heal fracture
can be used to study equine bone development and disease
CSC
stem cells in cancer
explain CSC
stem cells in cancer
very difficult to identify because the cells do not proliferate but these cells can lead to drug and treatment resistance
debated if CSC are in all cancers but definitely in Leukemia, prostate and breast
therapy targets both the stem cells and the niche cells that keep the stem cells alive
