Stem Cells Flashcards
Characteristics of a stem cell.
Not terminally differentiated
Can divide without limit
Undergo slow division
When divide gives rise to 1 cell with stem cell characteristics and the other with the ability to be differentiated
Adult stem cells are ______ specific.
Tissue
Ability to give rise to all cells of an organism, including embryonic and extraembryonic tissues (cells which support embryonic development).
Totipotency
e.g. zygote
Ability to give rise to all cells of the embryo and subsequently adult tissues.
Pluripotency
eg: embryonic stem cells
Ability to give rise to different cell types of a given lineage.
Multipotency
(adult stem cells)
A cell from a blastocyst is ______
Pluripotent
These cells differentiate into respective proportions of body parts where each cell has a fixed number of divisions.
Founder Stem Cells
Founder cells are controlled by what?
Short range signals that determine stem cell populations and operate for a few hundred cell diameters.
_____ are cells that divide frequently and become differentiated from stem cell.
Transit Amplifying Cells
Contribute to more cells needed.
Where do transit cell come from?
How many cell divisions do they have?
They leave the basal layer after differentiating from stem cells.
They have a finite number
What is the Immortal Strand Hypothesis?
Some tissues’ stem cells selectively retain original DNA as a way to prevent genetic errors in stem cells
This daughter cell will retain stem cell characteristics
How do stem cell differentiate?
Involve multiple factors that combine to produce epigenetic markers in the cell’s DNA that restrict DNA expression.
Stem cells derived from the blastocyst stage and that are capable of proliferating indefinitely in culture
Embryonic Stem Cells
When put into an adult will embryonic stem cells integrate?
What other things may they possibly integrate into?
No, they will however if put into an embryo
How are embryonic stem cells potentially dangerous?
Can become a tumor (teratoma)
What is the benefit of ES Cell therapy?
Induce development of specialized cell types while solving rejection problem
What have successful treatments in animal models been with stem cell?
Severe immune deficiency
Diabetes
Parkinson’s disease
Spinal injury
Demyelination
Myocardial infarction
These transcription factors are essential for pluripotent stem cells in the empryo
Nanog, Oct4, Sox2, and FoxD3
Never open spoiled feta.
This transcription factor is required during early stages of pluripotent cell differentiation
GCNF
Growth factors found in pluripotent cells
Cripto and GDF-3
Stem cell type from bone marrow.
Differentiates into blood components.
Hematopoietic Stem Cells (HSCs)
Comes from bone marrow
Differentiates into connective tissues, tissues.
Mesenchymal Stem Cells
What can supply both mesenchymal and hematopoietic stem cells without taking directly from embryo?
Cord Blood
What are the current strategies on using stem cells medically?
Use iPS (Patient derived)
Use non-patient derived (ES)
Reprogram primary cells
What are the potentially neuro-regenerative adult stem cells?
Bone marrow-derived mesenchymal stem cells (BMSCs): transplant
Adipose-derived mesenchymal stem cells (AMSCs): liposuction
iPS cells have a high potential for what dangerous side effect?
Teratoma formation
Due to viruses used to add genes and potential oncogenic factors.
What part of the blastocyst is removed in making iPS embryonic cells or in somatic cell nuclear transfe?
Inner cell mass
Challenges in SCNT
Inefficient (may need hundreds of oocytes)
Technically demanding - needs to be available in many or all hospitals
What is the environment that influences a stem cell known as?
A stem cell niche
Stem cells maintains telomeres via what?
Telomerase
Assymetric division in which one stem cell like cell is maintained through factors.
Divisional Assymetry
Assymetric divesion where environment may influence or alter one cell.
Environmental asymmetry
Why would the immortal strain hypothesis benefit a stem cell?
Reduce mutations from synthesizing a new cell
Why do we need serum free media for ES Cell growth?
Growth factors cause them to differentiate
LIF and certain cytokines are alright
What is the downfall in adult stem cells?
Restricted capacity to differentiate into various tissues, maybe with some plasticity but at a low frequency
What is a succesful therapy for Adult Stem Cells?
Hematopoetic stem cells repopulating bone marrow.
Incorrectly implanted and typed adult stem cells can cause what issue?
What are some solutions?
Immune rejection
Stem cell banks
Somatic cell nuclear transfer instead
Induced Pluripotent Stem Cells
SCNT in Disease treatment challenges
Inefficient (May need 100s of oocytes)
Technically demanding
