Summary iPSC: Induced Pluripotent Stem Cells

IPSCS : INDUCED PLURIPOTENT
STEM CELLS
WHAT ARE IPSC?

1. Can divide + create an identical copy of themselves = self-renewal
2. Can differentiate/mature into cells that make up every type or
several type of tissue(s) and organ(s) in the body =
pluripotency/totipotency/multipotency

STEM CELLS – POTENCY

 Four different types

Early embryonic cells Totipotency
Embryonic stem cells (ESC) Pluripotency
Adult stem cells (e.g. hematopoietic SC) Multipotency
Induced pluripotent stem cells Pluripotency




INDUCED

, IPSC DISCOVERY

- Started from fibroblast cultures
- There was induction of pluripotent stem cells from mouse embryonic or adult fibroblasts by
introducing 4 factors:
o Oct3/4
o Sox2
o C-Myc
o Klf4
- These were introduced under ES cell culture conditions
- These cells = iPSC, exhibit the morphology and growth properties of ESC and express ESC
marker genes
- Subcutaneous transplantation of iPSC into nude mice  °tumors containing a variety of
tissues from ALL 3 germ layers

HOW DO WE MAKE IPSC?

IPSC CREATION – SOMATIC CELLS

 there are some drawbacks:
o Moderately invasive
o UV exposure
 Alternatives
o Peripheral blood mononuclear cells
o Urinary cells
o Hair cells
o …

IPSC CREATION – YAMANAKA FACTORS

- Yamanaka factors = 4 genes that allow regular cells to transform into
induced pluripotent stem cells, iPSCs
o So that cells can become any type of cell
- 4 genes of Yamanaka factors:
o Oct4
o Sox2
o Klf4
o cMyc



 Mode of action
remains
completely
resolved