Specialized Tissues, Stem Cells, and Tissue Renewal II: Blood - Stem Cells

Question 1

What is a stem cell?

Answer 1

A primitive cell that can either self-renew (reproduce itself) or give rise to more specialized cell types.

Single stem cells differentiate into multiple, functional cell types.

Stem cells functionally reconstitute a given tissue in vivo.

Question 2

What is the definition of totipotency?

Answer 2

Ability of a cell to give rise to all cells of an organism, including embryonic and extraembryonic tissues (cells which support embryonic development.

e.g., a zygote is totipotent

Question 3

What is the definition of pluripotency?

Answer 3

Ability of a cell to give rise to all cells of the embryo and subsequently adult tissues (embryonic stem cells).

Question 4

What is the definition of multipotency?

Answer 4

Ability of a cell to give rise to different cell types of a given lineage (adult stem cell).

e.g., epithelial tissue can become either skin or a hair follicle, but could not become a liver cell

Question 5

What type of stem cell is an adult stem cell?

Answer 5

multipotent

Question 6

What type of stem cell is a zygote?

Answer 6

totipotent

Question 7

What type of a stem cell is an embryonic stem cell?

Answer 7

pluripotent

Question 8

List places in which adult stem cells are located.

Answer 8

• Bone Marrow (HSC, MSC, EPC)
• Cord Blood (HSC, MSC, EPC)
• Skeletal Muscle
• Heart Muscle
• Dental Pulp
• Skin
• Colon
• Liver
• Prostate
• Mammary Gland
• Eye
• Ear
• Fat
• Pancreas ?
• Peripheral Blood (extremely low %)

Question 9

List sources of hematopoietic stem cells?

Answer 9

• bone marrow
• peripheral blood
• umbilical cord blood
• fetus liver
• induced pluripotent stem cells (iPS cells)

Question 10

What is the common expressed surface marker for the erythrocyte lineage?

Answer 10

• CD34+

- CD38+

Question 11

What is erythroid differentiation mediated by?

Answer 11

erythropoietin

Question 12

At which cell type in erythroid differentiation is the nucleus lost?

Answer 12

reticulocyte

Question 13

What can mesenchymal stem cells (MSC) from adipose tissue differentiate into?

Answer 13

• bone, fat, cartilage
• muscle
• kidney
• vessels
• heart
• nervous system

Question 14

Give an example of cellular differentiation starting at a hematopoietic stem cell that has been injected into a patient during adult stem cell therapy.

Answer 14

> Outside of patient

 - hematopoietic stem cell multiplied in cell culture
 - transplant into the patient 

> Inside the patient

 - pluripotent stem cell 
 - multipotent stem cell 
 - myeloid progenitor cell 
 - RBCs

Question 15

True or False:

Most evaluations of existing data by experts on adult stem cells and expert scientific bodies state that evidence does not support the contention that “adult stem cells can replace embryonic stem cells”.

Answer 15

True

Question 16

Where are adipose derived mesenchymal stem cells (AMSCs) usually collected from?

Answer 16

liposuction

Question 17

What are bone marrow derived mesenchymal stem cells (BMSCs) used for?

Answer 17

• Transplants

- Male to femal bone marrow transplant resulted in Y chromosome neurons in brain (current research)

Question 18

What have both bone marrow derived mesenchymal stem cells (BMSCs) and adipose derived mesenchymal stem cells (AMSCs) shown to have the capacity to do?

Answer 18

Differentiate in vitro and in vivo into:

• chondrocytes
• myoblasts
• osteoblasts
• pancreatic beta-cells
• neuronal-like cells

Question 19

What different tissues does mesoderm differentiate into?

Answer 19

• cardiac cells
• hematopoietic cells
• mesenchymal cells
• smooth muscle

Question 20

What 2 reasons do transplant physicians select bone marrow for their source of hematopoietic cells?

Answer 20

(1) Extensive clinical data are available about marrow transplant outcomes.
(2) Extensive information is available about the marrow donation experience.

Question 21

What is the best allogenic blood/bone marrow donor for a recipient?

Answer 21

brother or sister

• only 25% of patients are that lucky - 1 in 4 chance that any child will match another child of the same parents.
• in 1% of cases - a parent may be a donor because of shared HLA types.

Question 22

What do autologous transplants rely almost exclusively on?

Answer 22

Peripheral blood stem cells (PBSCs) rather than marrow.

Question 23

Why do autologous transplants rely almost exclusively on peripheral blood stem cells (PBSC) rather than bone marrow?

Answer 23

• easier collection of cells
• more rapid hematopoietic recovery
• decreased costs

Question 24

Understand the difference between differentiation and de-differentiation.

Answer 24

Differentiation -> process by which a cell becomes specialized in order to perform a specific function, as in a liver cell, blood cell , or a neuron.

De-differentiation -> partially or terminally differentiated cell reverts to an earlier developmental stage, usually as a part of a regenerative process.

Question 25

Understand the difference between totipotency, pluripotency, and multipotency.

Answer 25

Also, understand where these forms of potency are lost during hematopoiesis.