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35 Cards in this Set
- Front
- Back
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What are the 2 requirements for the self-renewing capacity of stem cells?
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1. Must be able to divide into more stem cells
2. Must be able to differentiate into different stem cell types |
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What can totipotent stem cells produce?
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All 3 germ layers, extra-embryonic structures
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What can pluripotent stem cells produce?
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All 3 germ layers
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What can multipotent stem cells produce?
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>2 types of differentiated daughter cells
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What can monopotent stem cells produce?
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1 type of differentiated daughter cell
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How does the Immortal Strand Hypothesis explain how stem cells regenerate?
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all the 'tagged' parents migrate to the same daughter, producing stem cells and transit amplifying cells
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What are adult stem cells?
What are their roles? |
Undifferentiated cells found among differentiated cells in a tissue or organ
Maintain and repair tissue |
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What are mesenchymal stem cells?
How do they appear in adults and what can they become? |
Multipotent stem cells in the embryo that can differentiate into many cell types
Appear fibroelastic --> osteoblast/cyte, adipocyte, smooth muscle cell, chondrocyte (cartilage) |
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How does the proliferative potential differ between mesenchymal and embryonic stem cells?
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MSC = proliferation can be exhausted (telomeres)
ESC = unlimited proliferation potential |
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What can skeletal muscle stem cells become and where can they be found?
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Satellite cells, monopotent
On myofiber surface between sarcolemma and external lamina |
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What can hematopoietic stem cells give rise to and where can they be found?
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Multipotent - all blood cell types, plus myeloid and lymphoid lineages, macrophages, mast cells
Found in femur, hips, ribs, sternum |
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What is the biphasic model of injury response?
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If injury minor, resident stem cells in tissue repair
If injury major, circulating cells transdifferentiate or fuse with resident cells to fix damage |
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What are bone stem cell niches?
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Osteoblasts lining the inner surface of bone or vascular endothelium
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What is a stem cell niche?
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Tissues/subsets that provide a stable environment for stem cells - house, control self-renewal, regulates stem cell participation in tissue generation, maintenance
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What do the ECM and adhesion molecules do for niches?
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Secure spacially, modulate concentration of adhesive/signaling molecules
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Where is the hair follicle SC niche?
What does it contain? |
Niche - bulge 2/3 way up follicle
SC - multipotent --> replenish matrix stem cells, sebaceous gland, epidermal stem cells |
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Which stem cells communicate to produce skin stem cells?
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1. Hair follicle bulge stem cells
2. sebaceous gland stem cells 3. interfollicular epithelial stem cells |
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Where are colonic stem cells located?
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Multipotent SCs at base of crypts
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Where are gastric stem cells located?
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Isthmus and neck region
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Where are intestinal stem cells located?
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In crypt, just above paneth cells
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Where is the hair follicle SC niche?
What does it contain? |
Niche - bulge 2/3 way up follicle
SC - multipotent --> replenish matrix stem cells, sebaceous gland, epidermal stem cells |
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Which stem cells communicate to produce skin stem cells?
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1. Hair follicle bulge stem cells
2. sebaceous gland stem cells 3. interfollicular epithelial stem cells |
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Where are colonic stem cells located?
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Multipotent SCs at base of crypts
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Where are gastric stem cells located?
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Isthmus and neck region
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Where are intestinal stem cells located?
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In crypt, just above paneth cells
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How are stem cells in intestines kept separate from differentiated cells?
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Stem cells and paneth cells express EphB proteins --> keep in crypt
Differentiating cells express ephrin proteins --> keep out of crypt |
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Where are neural stem cells located and what type are they?
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Multipotent - located in the subventricular zone
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What are the germ line stem cells and where is the niche?
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spermatogonial monopotent stem cells in the seminiferous tubules
Niche provided by Sertoli cells, with growth factors and signals |
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What are transit amplifying cells and what is the role of telomerase in them?
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Transit amplifying cells arise from stem cells, divide a finite number of times, and differentiate into final tissues
Have telomerase, limited proliferative potential |
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How does the 'telomerase status' change through development of cells?
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1. Stem cells (basal) -Telomerase negative
2. Transit amplifying cells - telomerase pos. 3. terminally differentiated cells (apical) - telomerase neg. |
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What are embryonic stem cells?
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primitive stem cells from ICM of blastocyst
Unilimited symmetrical cell divisions without differentiating |
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Where are ESC totipotent vs. pluripotent
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Blatocyst -totipotent
Injected below kidney capsule - pluripotent |
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What is somatic cell nuclear transfer?
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Put nucleus of a differentiated somatic cell into enucleated oocyte --> therapeutic or reproductive
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What are induced pluripotent stem cells?
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Somatic cells that have been reprogrammed by expressing stem cell factors
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What diseases can telomerase mutations lead to?
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1. Dyskeratosis congenita
2. Sporadic bone marrow failure 3. Idiopathic pulmonary fibrosis |
