Stem Cell Therapy (Imelda)

Question 1

2 main categories of stem cell?

Answer 1

> embreyonic
- totipotent
adult (somatic)
- multipotent

Question 2

Where are embreyonic stem cells derived from?

Answer 2

Inner cell mass -> hypoblast and epiblast [epi gives rise to all cells in the adult]
(v trophoblast that will make placenta)

Question 3

Why is stem cell harvesting hard? Outline the process

Answer 3

• small number of cells
• short period of time before they begin to differentiate
  » need to be amplified by culturing (but still prevetned from differentiated)
• LIF feeder layer
• cells are passaged when they are confluent
  > cells can be induced to differentiate by adding growth factors and supplements (but not all of these are known recipes)

Question 4

Potential issues with stem cell tx?

Answer 4

• ethical issues of destroying an embreyo

- ES cells implanted ito a lesion may differentiate into incorrect tissue/teratoma : BAD

Question 5

CLinical trieal for ES cells in humans> ==?

Answer 5

> macular degeneration

• partially differentiated ES cells injected into eye
• RPE degeneration (feeds retina)

Question 6

What is ViaCyte?

Answer 6

Combination of implant and stem cells

Question 7

Whre can adult stem cells be found?

Answer 7

EVERYWHARRRR
- skin
- gut 
- brain (much less active) 
> limited potential

Question 8

How do adult stem cells behave?

Answer 8

• dormant
  = proliferate very slowly in situ
• limited potential

Question 9

Where can stem cells be harvested from?

Answer 9

• skin

- brain (MUch harder)

Question 10

Is amplification of adult stem cells easy?

Answer 10

Noooooope

• dont proliferate fast
• dont proliferate indefinitely

Question 11

What are iPSs? Pros and cons?

Answer 11

• adult somatic cells (usually skin firoblasts) transfected with a viral vector carrying stem cell genes
• become embreyonic again
  > PRos: easy to obtain and transform
• amplifiable and could be personalised (usaing ones own stem cells)
  > Cons: retain adult epigenetic profiles of methylation (effect of your distnat ancestors on our DNA)
• do not become fully embreyonic
• prematurely age and die
• poor proliferation profiles
• may be rejected in the same animals they were harvested rfrom

Question 12

Uses of stem cells in vet?

Answer 12

> horse tendon/ligament injury [VetCell licensced]
- mesenchymal stem cells from sternum
horse/dog bone/joint/tendon injury [VetStem in states]
- from adipose tissue
- fewer stem cells present so more amplification needed
provides favourable environment (growth factors etc.) for repair or regenerate themselves?? not known, does it matter?

Question 13

Side effects in vet usage of stem cells?

Answer 13

• few!
• some swwelling at injection site (reversible)
• long term nothing seen yet

Question 14

Potential future of stem cells?

Answer 14

> umbilical cord blood

may also be totipotent

Question 15

Define a stem cell

Answer 15

unspecialised cell with the ablity to self-renew and capability of differentiating into multiple cell types