Stem Cells and Regenerative Medicine* Flashcards
What are stem cells?
- Can differentiate into many different cell types depending on the types of signals received.
- Capable of self-renewal via cell division
- Provide new cells as an organism grows and can replace cells that are damaged or lost
Why are stem cells targeted by researchers?
Targeted by researchers for their therapeutic potential.
What are the different types of stem cells?
- Embryonic
- Adult
- Induced pluripotent stem cells
What are potential uses of stem cells?
- Stroke
- Baldness
- Blindness
- Myocardial Infarction
- Cancers
- Spinal cord injury
- Wound healing
What are Adult Stem Cells (ASCs)?
- Rare but replace dead or damaged cells.
- These are multipotent and tissue specific.
How can Adult Stem Cells (ASCs) be used?
- Scientists can take these and amplify and manipulate them in vitro allowing us to use them for a variety of purposes.
What type of stem cells are embryonic stem cells?
Pluripotent
Where are embryonic stem cells taken from?
Blastocyst
What are Embryonic Stem Cells (ESCs)?
- Pluripotent and supply all cells of developing embryo
- Can differentiate into any cell in the embryo.
- Stem cells reside in inner cell mass. ESCs can develop into any of the 3 embryonic germ layers (ectoderm, endoderm, mesoderm).
How do you create iPSCs?
Take any cell and expose it to specific plutipotency factors
What are the specific pluripotency factors?
Oct 4, sox2, KLF4 and Cmyp
What are Induced Pluripotent Stem Cells (iPSCs)?
- They are made in the lab and can be reprogrammed by specific exposure to a set of pluripotency factors. (E.g OCT4, SOX2, KLF4) to produce iSPCs with similar characteristics to ESCs.
Why are iPSCs used?
- These can be used for cell therapy repairing mutations using gene manipulation techniques e.g CRISPR and differentiating them in vitro and back to the patient.
- Cells are specific to the patient and reduce rejection by the host.
What are other uses of stem cells?
- Model for basic and translational studies
- Disease modelling
- Drug screening
- Cell replacement therapy
- Cell differentiation
- 3D organoid models
- Developmental biology
Where are stem cells maintained?
- Tissue-specific stem cells are maintained in special supportive microenvironments called stem cell niches – found at specific anatomical locations.
- Niches interact with stem cells to regulate cell fate and protect stem cells from depletion and the host from excessive proliferation.
- Different types of stem cells have different differential potentials.
What is the comparison of stem cell types?
What are the features of stem cell niches?
- Supporting ECM
- Neighbouring niche cells
- Secreted soluble signaling factors (e.g growth factors and cytokines)
- Physical parameters (e.g shear stress, tissue stiffness and topography)
- Environmental signals (metabolites, hypoxia, inflammation etc)
What are the advantages of ESCs?
Advantages
- Pluripotent - almost unlimited growth potential - may differentiate into any kind of cell
- Unlimited numbers of cells due to high cell potency
- Very low probability of mutation induced damage in the DNA
What are the disadvantages of ESCs?
Disadvantages
- Higher risk of tumour creation
- Risk of being genetically different from the recipient’s cells - higher risk of rejection
What are the advantages of ASCs?
Advantages
- Compatible with recipients cells - low risk of rejection
- Less risk of tumour creation
What are the disadvantages of ASCs?
Disadvantages
- Oligopotent - unipotent - limited cell potency
- Limited numbers may be obtained
- Higher probability of mutation-induced damage in the DNA - risk of dieases