Stem Cells Flashcards
A primitive cell that can either self-renew or give rise to more specialized cell types. It is highly regulated.
Stem cell
*progenitors are more differentiated (the original origin ones)
What are characteristics of stem cells?
- not terminally differentiated
- can divide without limit (bc telomerase expression)
- undergo slow division
- divide into 1 stem cell and 1 differentiated cell
Adult (mature) stem cells are known to be ________. They are committed to a specific lineage of the ectoderm, mesoderm, endoderm.
Tissue specific
The proliferative potential of a stem cell is know as its _______
Potency
Describe totipotency
- ability to give rise to all cells of an organism (embryonic and extra embryonic tissue)
- ZYGOTE of embryonic stem cell
Describe pluripotent
- ability to give rise to all cells of the embryo (not extra embryonic cells)
- blastocyst of embryonic stem cells
Describe multipotency
Ability to give rise to different cell types of a given lineage
*adult stem cells
(Adult/tissue/somatic stem cell)
T/F
Pluripotent embryonic stem cells can be isolated and cultured and grown into different tissue types such as pancreatic islet cells, hematopoietic cells, cardiomyocytes, neurons, and hepatocytes
TRUE
Ectoderm cell’s can become
Skin or neural cells
What makes you pretty: your outside (skin) and smarts (brain)
Endoderm cells can become
Lung, thyroid, or pancreas
Mesoderm cells can become
Cardiac cellls, hematopoietic, mesenchymal, or smooth muscle cells
Cultured pluripotent stem cells make:
_____ for leukemia patients
_____ for Parkinson’s and AD
_______ for heart disease
________ for diabetes
Bone marrow
Nerve cell
Heart muscle
Pancreatic islet cells
- short range signal determines the populations during development
- programmed to have a fixed number of divisions
- define the size of large final structures
Founder stem cells
*populations stay small but transit amplifying divisions let them generate and renew big adult structure
How often to transit amplifying cells divide ?
Frequently
Where do transit amplifying cells come from
Stem cell division; it is the cell that is carried on to be more differentiated
- it is committed
- have a finite number of divisions
Stem cells have divisional asymmetry. What does this mean? How is it different than environmental asymmetry ?
- division of stem cells = 50% exact stem cells with original DNA and 50% transit amplifying cells with committed lineage
- environment asymmetry means that environmental factors influence cell differentiation
What hypothesis summarizes that in asymmetrical stem cell division one daughter cell becomes a new stem cell with the exact DNA copy and the other daughter cell (transit amplifying cell) becomes differentiated and gets newly synthesizes strand of DNA
Immortal strand hypothesis
- way to prevent genetic error in stem cells
- result of semi-conservative DNA replication
- transit cells may get errors in newly synthesized DNA
What markers in the cell’s DNA is involved in stem cell differentiation and cause the restriction of DNA expression therefore determining the type of cell a stem cell with turn into
Epigenetic markers
Silencing of some parts of genes by methylation
In ES from the blastocyst, then can be placed back into ____ to integrate with the embryo, but if injected at a later stage or into an adult they will fail to differentiate properly and can become a tumor
Blastocyst
Es cells can give rise to what type of tumor? And is the downfall of ES stem cell use
Tertomas (with teeth and hair)
What are the transcription factors that are responsible for making ES pluripotent cells
Nanog, Oct4, Sox2, FoxD3
What are growth factors found in pluripotent cells that make it differentiate ?
Cripto and GDF-4
*GCNF important for early stage pluripotent cell differentiation
Adult stem cells respond to what
Respond to demands of growth and repair
*found in tissues
T/F
Adult stem cells may show relaxation of restrictions in an altered environment that can possibly account for some plasticity
True
*seen in low frequency’s
