Lecture 2: Stem Cells Flashcards

1
Q

Mention the two defining attributes of a stem cell.

A
  1. Asymmetric division: the ability to differentiate into many different cell types
  2. Self-renewal: the capacity to maintain SC population
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2
Q

_______________ are found only in early embryonic tissues and derive from the first few cell divisions after fertilisation.

A

Totipotent stem cells

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3
Q

Recall the range commitment options available to a cell.

A
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4
Q

_________________ is the latest developmental stage harboring pluripotent stem cells.

A

Blastocyst

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5
Q

Mention the changes that occurs during gastrulation.

A
  • Formation of primitive streak: defining all major body axis
  • Formation of the three germ layers: ectoderm, mesoderm, endoderm
  • Giving rise to distinct tissues in adult
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6
Q

Describe the fate of the three type of cells.

A
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7
Q

____________________ is isolated immediately following birth and has some pluripotent characteristics.

A

Placenta stem cells

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8
Q

Compare between adult and embryonic stem cells

A
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9
Q

What is a ‘stem cell niche’?

A

Stem cells exist in a microenvironment supporting their maintenance and normal function.

Examples such as the follicle bulge (reserve of skin stem cells), Paneth cells, and Neural Stem Cells in the subventricular zone.

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10
Q

The activation of adult stem cells can be _____ or ___________.

A

local, systemic

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11
Q

Explain stem cell mobilisation in the case of AMI.

A

In acute myocardial infarction, the ischemic injury caused to the myocardiocytes causes the release of chemokines, which mobilise quiescent stem cells from the bone marrow into the peripheral circulation.

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12
Q

How is stem cell activation analysed in the case of brain injury?

A

Nestin is a protein marker used to mark progenitor/stem cells. After brain injury, cell imaging would should higher readings of nestin.

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13
Q

Explain the mechanism of SC activation in liver injury.

A

When hepatocytes die, it releases signals which activated both the Kupffer and Hepatic Stellar Cells. Activated KC releases cytokines promoting proliferation (PDGF, TNF), contraction (ET-1), fibrogenesis (TGF-b), and chemotaxis (PDGF).

The activated stellate cell is characterized by proliferation, contractility, and chemotaxis. This state of the stellate cell is the main source of extracellular matrix production in liver injury.

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14
Q

What is the hematopoietic system?

A

The haematopoetic system is the system in the body involved in the creation of the cells of the blood.

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15
Q

Lymphocytes originate from __________ which differentiate into ______________.

A

Hematopoetic Stem Cell (HSC), Early Progenitor with Lymphoid Potential

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16
Q

Explain the mechanism of SCNT.

A

Somatic Cell Nuclear Transfer

It is a form of asexual reproduction, where no sperm is involved. Nucleus form the patient cell is transferred into a donor egg (nucleus removed). It requires an electric or chemical stimulus to begin dividing. It is functionally different from a regular fertilised egg.

17
Q

Describe briefly iPS.

A

Induced pluripotent stem cells are a type of pluripotent stem cell that can be generated directly from a somatic cell. Pluripotent stem cells hold promise in the field of regenerative medicine. Because they can propagate indefinitely, as well as give rise to every other cell type in the body (such as neurons, heart, pancreatic, and liver cells)ly from a somatic cell.

18
Q

Mention the advantage and disadvantage of the various types of stem cells.

A
19
Q

Describe briefly about cancer stem cells.

A

It has limitless replicative potential. It may arise through the transformation of a normal stem cell or through acquired genetic lesions that impart a stem-like state or a more mature cell.

20
Q

Define pluripotency.

A

It refers to a stem cell that has the potential to differentiate into any of the three germ layers: endoderm (interior stomach lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone, blood, urogenital), or ectoderm (epidermal tissues and nervous system), but not into extra-embryonic tissues like the placenta.

21
Q

Define multipotency.

A

Multipotency describes progenitor cells which have the gene activation potential to differentiate into discrete cell types.

22
Q

Define oligopotency and unipotency.

A

Oligopotency is the ability of progenitor cells to differentiate into a few cell types.

Unipotent cell is the concept that one stem cell has the capacity to differentiate into only one cell type.