iPSC technology Flashcards
properties of stem cells
differntiation and self renewal
totipotent stem cell
any cell in the body and placenta
pluripotent stem cell
can form any cell in the body
multipotent stem cell
can form into several different cell types
oligopotent stem cell
can form into a handful of different cell types
unipotent stem cells
can differentiate into one cell type
which stem cell class can differentiate into any of the germ layers?
pluripotent
embryonic stem cells are an example of what class of stem cell?
pluripotent
where are embryonic stem cells located?
inner cell mass of blastocyst
what stem cell class are adult stem cells?
multipotent
what are iPSC derived from?
terminally differentiated stem cells
what transcription factors are used to revert cells back to pluripotency?
oct 4, sox2, klf4 and cmyc OR oct4, sox2 nanog and lin-28
how can cell pluripotency be established?
make sure they can differentiate into the germ layers AND that theyre incorporated into growing embryo
where does Oct-4 bind?
octamer motif
what gene produces oct-4?
pou5f1
how does octamer motif regulate gene expression?
promoter or enhancer
which TF are essential to maintain pluripotency?
sox2 and oct-4
which TF activates oct-4 and sox-2?
KLF-4
role of c-myc
stimulate cell proliferation
what is used to introduce genes into the genome?
viral vectors
iPSC risks
insertional mutagenesis , genome instability and maligant transformation
why did mice which developed from embryos containing iPSC develop tumours?
c-myc is an oncogene
oct-4, sox2 and klf4 transduction carries what risk?
tumour formation
alternative technqiues
piggyBac,
replication-defective adenoviral vectors
episomal plasmids
non-viral minicircle
piggyBac
involves no genetic integration
replication defective adenoviral vectors
genetic material of cells not altered, but oct4 is expressed by the genes that were inserted
episomal plasmids, non-viral minicircle DNA vectors and replication-defective adenoviral vectors
also non integrating
how are transcription factors delivered?
integrating viral vectors
how does OCT-4 affect transcription?
binds to ATGCAAAT of promoter or enhancer of target genes
Oct-4 expression after the 8th day of gestation
only within germ cells
where is Oct-4 expressed in the blastocyst?
inner cell mass
what transcription factor activates sox2 and oct4?
kfl
piggyBac
transposon into somatic cells
describe when different growth factors exert their effects
different stages of embryonic development
growth factor required for midbrain/hindbrain development
FGF8
growth factor required for spinal cord development
RA
growth factor needed for forebrain development
alpha BMP
alpha WNt
what do stem cells require to develop into neural progenitor cells?
alpha BMP
alpha Wnt
FGF
what are the only cerebellar cortex output cells?
Purkinje cells
describe the activity of Purkinje cells:
provide GABA-ergic inhibition to modulate input to cerebellar nuclei
what cells are lost in ataxia telengiactasia
Purkinje cells
human iPS cell-derived neurones have improved symptoms of whar disorder in rodents?
Parkinson’s
Future applications of new tissue generation:
1.individual specialised cell generation
2. tissue patches
3. tissue organoids
why can inherited diseases be modeled using iPSC?
mutation sequences remain throughout the process
Future applications of iPSC in disease modelling:
drug screening
patient-specific therapies
modelling epigenetic disorders
why can iPSC be used in patient-specific therapies?
specialised cells maintain genes of the donor
how can cardiomyocytes be produced?
de-differentiation of fibroblasts
how can rett syndrome be modelled?
IPS-neurons
long-QT syndrome mutation:
KCNQ1
Rett syndrome mutation:
MECP2
effect of IGF1?
increased glutamatergic synapse number and soma size
