Stem Cells Flashcards
This is a primitive cell that can either self-renew or give rise to more specialized cell types. They differentiate into multiple, functional cell types.
Stem cells
Stem cells functionally reconstitute a given tissue _______. For example, one blood stem cell gives rise to red cells, white cells, and platelets.
In vivo
What are the characteristics of stem cells?
- Not terminally differentiated
- Can divide without limit
- Undergo slow division
When stem cells divide, what happens?
Give rise to 1 cell with stem cell characteristics and the other with the ability to be differentiated.
Adult stem cells are _______ specific.
Tissue
This type of potency is the ability to give rise to all cells of an organism, including embryonic and extraembryonic tissues (cells which support embryonic development).
Totipotency
What is an example of totipotency?
Zygote
This type of potency is the ability to give rise to all cells of the embryo and subsequently adult tissues (embryonic stem cells).
Pluripotency
***i.e., Blastocyst of embryo
This type of potency is the ability to give rise to different cell types of a given lineage (adult stem cells).
Multipotency
***i.e., tissues from endoderm, ectoderm, and mesoderm
In these stem cells, the proportions of body parts are determined early. Each tissue has a fixed number of these cell populations. Programmed to have a fixed number of divisions controlled by short range signals that operate for a few hundred cell diameters. Defines size of large final structures.
Founder stem cells
This type of cell are cells that divide frequently. They move from a cell with stem cell characteristics to a differentiated cell and leave the basal layer and incorporate into the layers above.
Transit amplifying cells
Transit amplifying cells are programmed to have a limited number of divisions (finite), which part of the strategy for growth control. They are _________.
Committed
For a steady pool of stem cells, half of daughter cells must remain as stem cells to retain original DNA. This is accomplished by…
Divisional asymmetry
Environmental asymmetry
This is the term for an asymmetric division that may create 2 cells, one with stem cell characteristics and another with factors that give it the ability to differentiate.
Divisional asymmetry
This is the term for a division that makes 2 identical cells but environment may influence/alter one cell.
Environmental asymmetry
This is the term for the idea that some tissues stem cells selectively retain original DNA, which is a way to prevent genetic errors in stem cells. When divided, one daughter cell will retain the stem cell characteristics and the original strand of DNA is preserved in stem cells from generation to generation. The second cells gets the newly synthesized strand.
Immortal strand hypothesis
Embryonic stem cells are (PLURIPOTENT/MULTIPOTENT), meaning they can become any cell in the body. Adult stem cells are undifferentiated and generate cell types in the tissues in which they reside, making them (PLURIPOTENT/MULTIPOTENT).
Pluripotent
Multipotent
Stem cells differentiate into specialized cells in stages. Stages involve multiple factors that combine to produce epigenetic markers in the cell’s DNA that restrict DNA expression and thus the type of cell that the stem cell will differentiate into. DNA expression can pass on to daughter cells through cell division or they can retain stem cell status and capability for long-term renewal (i.e., _______ _______ _______).
Immortal strand hypothesis
Embryonic stem cells are derived from the ________ stage of embryo. They are capable of proliferating _________ in culture. Have unrestricted developmental potential.
Blastocyst
Indefinitely
When embryonic stem cells are put back into the blastocyst, they can integrate well with the embryo and develop into different cel types. What happens if they’re injected to an embryo at a later stage or into an adult?
They fail to receive appropriate sequence of cues for proper differentiation. Can become a tumor.
Embryonic stem cells can give rise to _________, which have the ability to differentiate into a wide range of tissues (can have teeth, hair, bone, etc.). They do not display axis formation or segmentation. ES cells are incapable of generating the body play on their own like embryos.
Teratomas
This type of stem cell can be found in their blood and bone marrow. It has a greater potency than adult stem cells, but less than embryonic stem cells. Also less ethically contentious.
Fetal stem cells
This type of stem cell is found in the umbilical cord and are undifferentiated. No need for gene manipulation and can be banked for use in later life.
Cord blood stem cells
This type of stem cell is reliable, has highly reproducible results, and is ethically contentious.
Embryonic stem cells
This type of stem cell is done by inducing transcription factors to reprogram adult cells into stem cells. High potential for teratomas.
Induced Pluripotent stem cells (iPS)
This type of regenerative medicine combines cloning with stem cell research. The nucleus of a somatic cell is planted into a donor egg cell, and this regenerates an individuals own embryonic stem cells.
Somatic Cell Nuclear Transfer (SCNT)
What do ES cells differentiate into when injected into host animals?
Cartilage Bone Skin Nerves Gut and respiratory lining
ES cells + retinoic acid and insulin, thyroid hormone, form what type of cells?
Adipocytes
ES cells + retinoic acid form what type of cells?
Neurons
ES cells + macrophage colony-stimulating factor, IL-3, and IL-1 form what type of cells?
Macrophages
ES cells + dibutyryl cAMP and retinoic acid form what type of cells?
Smooth muscle cells
ES cells + fibroblast growth factor (FGF), FGF-2 form what type of cells?
Astrocytes and Oligodendrocytes
ES cell therapies help to induce development of specialized cell types and to solve the ________ problems often occurring in transplants.
Rejection
What are the transcription factors essential for establishment and maintenance of pluripotent stem cells in the embryo?
Nanog
Oct4
Sox2
FoxD3
This is required for early stages of pluripotent cell differentiation.
GCNF
What are the growth factors found in pluripotent cells?
Cripto
GDF-3
This type of stem cell is found in tissues, and responds to demands of growth/repair. It is strictly imposed by molecular restraints on gene expression.
Adult stem cells
Adult stem cell therapy can be used for what?
Neuro-regeneration
T/F. Adult stem cells have a restricted capacity and growth potential. Harvested cells retain properties of the original tissue type, so you cannot coerce them to express characteristics of different tissue type.
True
Both of these types of stem cells come from bone marrow and differ in what they can be differentiated as.
Hematopoietic stem cells (become blood components)
Mesenchymal (stromal) stem cells (become connective tissues, tissues)
This is a serious problem in adult stem cells. If genetically different, grafted cells can be rejected by host (requires identical genotype).
Immune rejection
In iPS cells, the introduction of what transcription factors can induce adult human cells to exhibit properties of ES cells?
Oct4
Sox2
Nanog
Lin28
Explain how SCNT can be used to treat Type I diabetes.
The somatic cell nucleus is implanted into a donor egg cell. It becomes a blastocyst, and the ES cells are removed and differentiated into pancreatic stem cells. These cells are then injected into the pancreas where they become pancreatic cells that can successfully secrete insulin.