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34 Cards in this Set
- Front
- Back
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What does it mean to be pluripotent?
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Stem cell can be programmed to reconstitute any of the 200 tissues in the body.
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What does it mean to be totipotent?
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Stem cell has capacity to make a whole embryo and organism
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What does it mean to be multipotent and what is an example?
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Adult stem cells that cannot reconstitute all cells of the body.
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Where are multipotent SC found?
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In heterogenous clusters in bone marrow.
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Where do embryonic stem cells reside?
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inner cell mass of 1-week old embryos (or blastocysts)
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Reprogrammed adult cells that are forced to become stem cells are called:
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iPSC - induced pluripotent stem cells
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Where are adult stem cells found?
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Bone marrow
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Where are resident adult stem cells found?
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In adult tissue
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What are and where are unipotent stem cells found?
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They are resident adult stem cells that can be found in niches within individual organs.
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What are 1-week old embryos called?
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Blastocysts
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What happens when pluripotent ESCs are placed in cell culture?
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The spontaneously differentiate into any of the differentiated cell types of the body.
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Attempting to mimic what stage of life is one way to induces SC to differentiate in a specific manner:
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Mimicking embryogenesis
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What factors go into mimicking embryogenesis (3)?
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1. Timing
2. Growth factors 3. Signaling molecules |
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What is Somatic Cell Nuclear Transfer?
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Transfering the genome from skin cell (for example) into an enucleated female ovum, resulting in the creation of a clonal blastocyste (embryo)
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How is therapeutic cloning different than SCNT?
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It is halted at the blastocyst stage via removal of the inner cell mass. These inner mast cells are then expanded via specific differentiation to obtain transplantable cells for implant into donor pts
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What cells can be used to avoid the ethical problems associated with therapeutic cloning?
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iPSCs
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How are iPSCs made?
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Using fibroblasts and a cocktail of proteins that regulate gene expression - inducing reversion to stem cells.
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Besides the therapeutic potential of iPSCs, what else might they be used for?
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Disease in a dish - providing a platform for drug discovery, drug toxicity, therapeutics, or understanding disease
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What are the two major strengths to using ESCs therapeutically?
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1. To test novel drugs
2. Can expand to all tissue types |
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What are the three weaknesses to ESCs?
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1. Zoonotic disease transmission due to necessity to grow ESCs on feeder cell layers from mouse fibroblasts
2. May form tumors 3. Might be immunologically rejected by receipients |
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What is the largest objection to use of ESCs?
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Ethical
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What four transgenes can be used to induce fibroblasts into pluripotency?
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1. Oct4
2. Sox2 3. Nanog + Lin28 (Wisconsin) 4. Klf4 + cMyc (Japanese) |
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Adult stem cells can be divided into 4 subcategories including:
Also, where are they found? |
1. Circulating endothelial progenitor cells (EPCs) (Bone marrow)
2. Hematopoeitic stem cells (HSCs) (bone marrow) 3. Mesenchymal stem cells (MSCs) (bone marrow) 4. Resident adult stem cells (bone marrow) |
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What tissues can circulating (endothelial) progenitor cells (EPCs) regenerate? What can they generate a few of, however? What might they ultimately be used for?
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1. Endothelial cells of the heart
2. Smooth muscle cells Generates only a few cardiomyoctes - might be useful for treating ischemia |
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What is the surface marker on EPCs that classify them as such?
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CD34+
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What marker on Hematopoietic Stem Cells (HSCs) characterize them as such?
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c-kit+
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What can Mesenchymal Stem Cells (MSCs) differentiate into?
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Osteoblasts, chondroblasts and adipocytes
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How was it demonstrated that MSCs can repair lung?
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Mice were injected with label MCS. They migrated to the bone marrow. Lung injury was induced, and it was observed what cells repaired the tissue - it was the labelled MCS.
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What are the four strengths for using adult stem cells?
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1. Avoid zoonotic disease
2. Tumor potential min. 3. Autologous transplantation 4. Ethical concerns minimal |
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What are the two disadvantages to using adult stem cells?
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1. Limited differential outcomes
2. Fuse with existing target tissues rather an establishing new ones 3. Once you inject, MSCs, you can get them out. |
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Where can you find resident adult stem cells in the following tissues:
1. Skin 2. Intestine 3. Skeletal muscle 4. Brain |
1. skin = bulge of hair follicle
2. GI = Crypts of small intestine 3. Skeletal muscle in myo-satellite cells 4. Brain in sub-ependymal cells? |
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What are the four strengths to using resident adult stem cells?
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1. Restricted differentiation = min tumor formation
2. Zoonotic disease min 3. Autologous transplantation 4. Ethical concerns minimal. |
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What is the major weakness of using resident adult stem cells?
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Difficult to isolate and purify
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What was the example he used to demonstrate the weakness of using resident adult stem cells?
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Myo-satellites cells have been used to treat muscular dystrophy and cardiac insufficiency; however former treatment failed to keep up with dystrophic process and later caused cardiac arrhythmias.
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