Stem cells Flashcards
(38 cards)
What is totipotent?
Capable of giving origin to a new individual (e.g. fertilised egg and first 4 cells produced by its division)
What is pluripotent?
Differentiate into almost all types of adult cell but not into foetal or adult animal (e.g. embryonic stem cells)
What is multipotent?
Gives rise to more than one type of specialist cell (e.g. adult mesenchymal stem cells)
What is oligopotent?
Able to differentiate into a few cell types (e.g. myeloid stem cells)
What is unipotent?
Able to differentiate into a single cell type
What are the major groups of stem cells (4)?
- Embryonic stem cells
- Induced pluripotent stem cells (iPS cells)
- Foetal tissue and umbilical cord stem cells
- Adult (somatic) stem cells
What are the different types of adult (somatic) stem cells (3)?
- Haemapoietic stem cells
- Bone marrow derived mesenchymal cells
- Mesenchymal cells
What are the different properties of stem cells?
- immature, non-specialised and able to differentiate within adult organisms
- capable of self renewal
- clongeneicity
- expression of verified stem cell markers
- can be induced experimentally to differentiate into various cell lineages
- Adult stem cells can be transplanted from one area and grow into a different type of tissue
What are the different types of dental stem cells (5)?
- Dental pulp stem cells (DPSCs)
- Stem cells from human exfoliated deciduous teeth (SHED)
- Periodontal ligament stem cells (PLSCs)
- Dental follicle stem cells (DFSCs)/ Dental follicle progenitor cells (DFPCs)
- Stem cells from the apical papilla (SCAP)
Which dental stem cells come from permanent teeth pre-eruption?
SCAPs, DPSCs, DFPCs, GSCs
Which dental stem cells come from permanent teeth after eruption?
PDLSCs, DPSCs
Which dental stem cells come from deciduous teeth before exfoliation?
DPSCs
Which dental stem cells come from deciduous teeth after exfoliation?
SHED
Which dental stem cells come from the tooth germ?
DFPCs
What are the potential dental applications for dental stem cells (5)?
- Pulpal regeneration in endodontics
- Periodontal regeneration including guided tissue regeneration
- Craniofacial regeneration
- Dental implantology - new bone formation
- Engineering of new teeth (bio teeth)
What are some of the potential medical applications for dental stem cells (6)?
- Treatment for liver disease
- Muscular dystrophy
- Stroke
- Diabetes
- Spinal cord regeneration
- Cardiac repair
Tell me more about dental pulp stem cells (DPSCs):
- Found in a quiescent state in healthy pulp but source of odontoblasts to form tertiary dentine,
- Experimentally:
- found to produce tubules similar to dentine,
- forms pulp-dentine like complex (without epithelial-mesenchymal interactions),
- less good osteogenesis,
- but shown to be adipogenic, neurogenic, chondrogenic and myogenic in vitro
Tell me more about stem cells from exfoliated deciduous human teeth (SHED):
- High rate of proliferation
- Osteogenic, adipogenic, neurogenic, myogenic and chondrogenic in vitro
- regenerate pulp like complex (but not dentine-pulp complex) in vivo
- repair bone defects in mice
Tell me more about periodontal ligament stem cells (PDLSCs):
- Homeostasis and regeneration of periodontal tissues or defects (prevents ankylosis)
- Differentiates to form cementoblasts, osteoblasts and fibroblasts
- Experimentally:
- forms fibroblasts
- osteogenic, cementogenic, adipogenic, neuronal precursors
- potential to regenerate PDL in people with perio
- cementum/PDL like complex -> dense collagen type 1 with sharpey like fibres embedded into cementum in vivo
- expanded tem cells on 3D scaffolds = bone formation
Tell me more about dental follicle stem cells (DFSCs)/Dental follicle precursor cells (DFPCs):
- Dental follicle = precursors for PDL, cementum and bone
- Source from impacted 3rd molars - can be cryopreserved
- Potential tissue engineering application (complete peridontium) but not observed in vivo yet
- cementogenic, adipogenic, neurogenic and osteogenic in rats at ectopic sites
- characteristics vary across species studied
Tell me more about Stem cells from the apical papilla (SCAP):
Apical papilla = soft tissue at apices of developing permanent teeth
- source of primary odontoblasts for development of root dentine
- Experimentally:
- high proliferative potential
- forms odontoblast-like cells and produce dentine in vivo
- adipogenic and neural cell markers
- Possibly the best source for root dentine formation
Why is isolation of stem cells challenging?
- Identification of the niche where they reside and are able to retain their “stemness” not fully understood
- Lack of specific markers
- Large number needed for stem cell replacement therapy (in vitro expansion)
- Needs growth factors and or extracellular matrix components to stop differentiation
What do stem cell markers CD146 and STRO-1 suggest about location of DPSCs?
Located in perivascular and perineural sheath regions
Where are most stem cells found?
Around blood vessels (n.b. not in all tissues)
