Stem cells Flashcards
(24 cards)
What is the definition of a stem cell?
An unscpecialised cell with the ability to self renew and differentiate into multiple cell types
Embryonic stem cell are ****potent
Adult stem cells are ****potent
toti
multi
Of the epiblast and the hypoblast whihc gives rise to the adult cells?
epiblast –> all adult cells
Where do embryonic stem cells come from?
The inner cell mass (small number hence must be amplified)
What is the culture we put stem cells in to make them divide?
Feeder layer
Selective media is then used to make them divide into a particular cell type (knowledge lacking on conditions needed to make some cells types)
What is stargardt disease?
Macular degeneration (juvenile)
What is dry AMD?
Macular degeneration (age related)
What are the two most common causes of blindness?
Stargardt disease and dry AMD
How do stargardt disease and dry AMD cause blindness?
Degeneration of the RPE at the back of the eye
50% had vision improvements with stem cell therapy
What are the three pros of embryonic stem cells?
The cells are totipotent
they can divide indefinitely in feeder layer
They cells are young (telomere length)
What are the five cons of embryonic stem cells?
Hard to get hold of (less so in animals)
Amplification takes a long time
sometimes differentiate wrong
Sometimes get teratomas developing
Ethical issues
Where are stem cells found in the adult?
Pretty much all tissues!
Needed so that the tissue can grow and repair
e.g. in intestine, at the bottom of the villi is the stem cell layer. Cells mature as they go upwards
What are the cons of using adult stem cells versus embryonic
Slow growing-hard to generate enough cells to be useful
Limited potential, and we don’t really know how to make cells divide into the cells we want!
Give an example of a stem cell type that is hard to harvest in adults?
Brain stem cells
skin=easy
What are the pros of adult stem cell collection?
Ability to harvest them for an individual reduces rejection
Less ethical debate
Less risk of teratoma formation as limited eventualities
Give two examples of transpoants that are currently available which use stem cells?
Bone marrow transplant
Trachea transplant
What are iPS cells?
Induced plurpipotent stem cells
Currently mainly harvested from tskin fibroblasts which are then reprogrammed
What are the pros of making iPS cells?
Easy to amplify
Make all cell types
No ethical concerns
What are the cons of iPS cells?
Don’t quite share all the properties of embryonic cells..
They have shorter telomere length and different gene expression
iPS cells also seem to have higher death rates and problems with premature ageing
Immunogenic?
What is the main field in which stem cells are used in the veterinary field?
Musculoskeletal use of mesenchymal stem cells
What can mesenchymal stem cells make?
Osteoblasts, Chondroblasts, Adipoblasts, Tendenoblasts and Myoblasts
(i.e. bone, cartilage, fat, tendon and muscle)
Where do we harvest stem cells from in animals for treatment?
Bone marrow from sternebrae (horses-VetCell)
Adipose tissue-small animals (vet-Stem) however many fewer MSC but easier to access
what are the side effects of stem cell injection into tendons?
Surprisingly few
Don’t seem to get cells differentiating into things they shouldn’t as they have been pre-differentiated
Some swelling at the injection site but does go down
Cancer link? Not proven
Why is it useful to store cells from the umbilical cord?
They may be totipotent
Treatment application in Leukemias etc?
