3: L15 Flashcards
3 types of stem cell
embryonic
iPSC
Adult
are blastomeres (2-4 cells) and blastocysts pluripotent or totipotent
Blastomere= toti
Blastocyte= pluripotent
why is blastocyte pluripotent not toti
give rise to all lineages of embryo proper but cannot contribute to extraembryonic trophectoderm
ESC uses
- Study in tissue culture to understand factors controlling cell differentiation. ESC lines.
- Derived from spare embryos from in vitro fertilisation
- Study which factors control cell into different phenotypes
Embryonic stem cells markers
Nanog, Sox 2, Oct 4
describe process of Somatic cell nuclear transfer and who did the first
- 1962 John GurdonSomatic cell nuclear transfer (therapeutic cloning)
- Egg and somatic cell (non-germline), Egg enucleate
- Somatic cell nucleus isolated
- Egg and somatic nucleus combined together
- Cell contains genetic material of donor
- Egg turns cell into Totipotent state (maternal factors)
- New (cloned ) organism develops
why is clinging controversal
- Status/quality of ‘aged’ DNA (+ genes/environment not known)
- Role of maternal cytoplasmic factors and mtDNA
why are autologous ESC used for transplantation
- Autologous cells (same person) avoid problems of immune rejection of foreign (non-self) donor cells.
Name 3 types of adult stem cells
- Hematopoietic stem cells
- Intestinal stem cells
- Mesenchymal stem cells
Name 2 adult stem cell markers for an adult stem cells
- Hematopoietic: CD34, Sca-1
2 uses for adult stem cells
Tissue engineering ex vivo to produce spare parts
Tissue repair by cell therapy
describe Stem cell niches
- Stem cell niches = environment in which they reside
- Niches - dominant part in regulating stem cell activity and behaviour
- Represents significant entry point for therapeutic modulation of stem cell behaviour
- May influence progression of degenerative and malignant diseases
Describe example of adult stem cell: satellite cell
- Self-renewal, activation, and differentiation of satellite cells in adult skeletal muscle
- Satellite cells reside adjacent to plasma membrane under basal lamina
- Syncitium of myonuclei positioned at periphery
- Satellite cells activated via external stimuli and differentiate together with upregulation of MyoD
when are • Most cells in brain are born and where from
during embryonic and early postnatal development
• New neurons generated throughout adult life from at least 2 areas of brain
- olfactory bulb + hippocampus
when can • Neurogenesis in non-neurogenic regions occur
trauma
- arise from NSCs
decribe differences between adult and embryonic neurogenesis
Embryo= Establishes cortical layers , adult= adds to
Embryo= Occurs at high levels, adult= low
Embryo= Occurs all regions of developing brain, adult= hippo + OB
Embryo= New neurons migrate to outer layer
using radial glia, adult= migrate specific positions through white matter
Embryo= Produces all types of neurons, adult= environment influences production
Yamanaka factors
o SOX2, OCT4, klf-4, c-myc
what can iPSC be used for
transplantation
disease modelling
drug development
benefits of iPSC
reduced ethics
disease understanding
patient specifity
more federal funding
how are iPSCs made
overexpression of all/some yamanaka factors- depending on what is already expressed
of the 3 stem cells, which can produce an immune response
embryo
of the 3 stem cells what is their origin + location
e= inner cell mass X 2
a= unknown, differentiated tissues in body
i= differentiated cells in body, unknown
potential function of the 3 stem cells
e= provides source for 3 germ layers in development
a= tissue replacement and repair through life
i= patient specific pluripotent stem cells for potential regeneration medicine
differentiation potential of the 3 stem cells
e= pluripotent
a= multi
i= pluripotent
