Stem Cells

Question 0

Embryonic stem cell

Answer 0

Can become almost any cell type in body (pluripotent)

Question 1

What is a stem cell?

Answer 1

Single cell that can replicate self or differentiate into many cell types

Question 2

Adult stem cell

Answer 2

Differentiate into subset of related cell types (multipotent)

Question 3

Embryonic stem cells can…

Answer 3

• treat many diseases
• ethical issues
• genetic engineering in mammals (knock out gene in mice)
• core set of transcription factors (OSKMs) maintain ES cell

Question 4

Induced pluripotent stem cells (iPS)

Answer 4

• from patients own cells
• can cure diseases
• safety is not 100%
• differentiated cells can be produced from cultured iPS cells

Question 5

Adult stem cells

Answer 5

• important in growth, healing, and repair of cell loss via wear and tear
• blood & bone marrow stem cells used to treat disease (rare and can only become a subset of related cell types)

Question 6

What are the 2 types of Adult (somatic) stem cells?

Answer 6

1. Stem cells in epithelia of small intestine

2. Haematopoietic stem cells

Question 7

Stem cells in small intestine

Answer 7

• renew itself at greater rate than any other tissue in the body
• molecular mechanisms well understood

Question 8

Absorptive cell (small intestine)

Answer 8

Take nutrients from gut lumen

Question 9

Goblet cell (small intestine)

Answer 9

Secrete protective coat of mucus

Question 10

Parieth cell (small intestine)

Answer 10

Secrete protein to kill bacteria

Question 11

Enteroendoceine cell (small intestine)

Answer 11

Secrete serotonin and peptide hormones to regulate growth

Question 12

2 fates of stem cell’s daughter cells

Answer 12

1. Self renew

2. Terminally differentiated cell

Question 13

2 types of ways to divide (daughter cells)

Answer 13

1. Asymmetric division

2. Independent choice

Question 14

Asymmetric division

Answer 14

Determined by asymmetry in dividing stem cell

Question 15

Independent choice

Answer 15

Determined by stochastically or/and environment

Question 16

Parieth cells create stem cell niches…

Answer 16

• at the bottom of crypt in small intestine
• room for 15 stem cells at bottom of each crypt
• not enough room for all cells so some forced to move up and as a result differentiate

Question 17

WNT signaling

Answer 17

Maintains pathway for proliferation

Question 18

NOTCH signaling

Answer 18

Inhibit pathway to differentiation

Question 19

In Adenoma what happens?

Answer 19

WNT signaling cannot be turned off as cells move up and differentiate so they continue to divide

Question 20

Haematopoietic stem cells

Answer 20

• all types of blood cells are made by a common stem cell in one marrow: H. Stem cells
• most complex stem cell system
• commitment is a stepwise process
• single stem cell fan reconstitute entire blood system (in mice)
• ## in humans same process used to treat/ eukaemia by bone marrow transplant

Question 21

Haematopoietic stem cells depends on contact with stromal cells

Answer 21

• when contact is lost, stem cell loses stem cell potential

- stromal cells is not complete dependence of stem cells, as same have been found in blood stream

Question 22

Cancer stem cells

Answer 22

• can be responsible for growth of some rumors
• radiotherapy or chemotherapy often kill fast feeling cells, but slow growing cells not killed causing the disease to resurrect