Flashcards in Week 5: Stem Cell Therapy Deck (7)
What are the main differences between embryonic and adult stem cells?
Embryonic Stem Cells
-origin: from inner cell mass of blastocyst
-unlimited self renewal capacity
-iPS (induced pluripotent stem) cells: somatic adult cells forced into ES cell state. Expression of Oct4, Sox2, Klf4, c-Myc
Adult Stem Cells
-in body's tissues, e.g. blood, brain, liver
-committed to becoming cell from tissue of origin
-can't be grown indefinitely in lab
Describe neural stem cells and list two main sties where neural stem cells reside in the adult brain
-type of adult stem cell
-self-renew, can produce neurons, astrocytes, oligodendrocytes
-found in sub ventricle zone of lateral ventricle and dentate gyrus of hippocampus
-can be derived from ES and iPS cells
-growth factors that promote propagation in lab: bFGF (basic fibroblast GF), EGF (epidermal gf), LIF (leukemia inhibitory factor), proteins that activate Wnt signaling
What are the sources of neural stem cells?
1. fetal brain from aborted fetus
2. adult brain biopsy
3. Human ES cells
4. Human IPS cells
5. NCS from somatic cells via reprogramming
What are the therapeutic approaches using neural stem cells for the treatment of neurological diseases and injuries?
-replace missing or damaged cells
-remyelination for e.g. spinal cord injury
-promotion of host tissue regeneration: parkinsons, stroke
-enzyme replacement therapy for neuroprotection
-tumor localized chemotherapy production
-drug discovery via stem cell based disease models
What are the current limitations and challenges of neural stem cell therapy?
-generating pure populations of NSCs that are functionally equivalent to in vivo counterparts
-ensuring quality of NSCs and derivatives
-improving survival of implanted cells
-impact of cell delivery in host brain
-need to maintain existing connectivity while supporting new therapeutically relevant cell integration
-overcoming or using endogenous signals that impact fate of implanted cells
-overcoming scar formation
How may stem cell therapy be used to treat Parkinson's Disease?
-grafted dopaminergic neurons into striatum where there is normally lots of dopamine
-intrastriatal transplants of fetal mesencephalic tissue
-problems: lack of tissue for transplantation, variability in outcome, dyskinesias