(L15) Stem Cell Applications

Question 1

What are the characteristics of stem cells? L15 S8

Answer 1

• not terminally differentiated
• can divide without limit
• slow division
• when dividing, give rise to 1 stem cell and 1 cell that will differentiate

Question 2

What are totipotent, pluripotent, and multipotent stem cells? Where are they seen? L15 S9

Answer 2

Totipotent: -can give rise to all cell types, embryonic tissue, and extraembryonic tisses -seen in the first 16 cells of a zygote

(EMBRYONIC)

Pluripotent: -can give rise to all cell types and embryonic tissues (after 16 cell morula stage)

• -inner cell mass of blastocyst
• (EMBRYONIC)
• unrestricted devleopment potetntial

Multipotent: -can give rise to all cell types but only of a certain lineage

• -adult stem cells found in various tissues

Question 3

What are founder stem cells? L15 S14

Answer 3

Stem cells that are generated early in development and have a fixed number of divisions they will undergo. This responsible for limiting the size of the final structure they will produce.

finger is gonna have less than your arm

-each tissue has a fixed number of founder cells in population and are controlled by a short range of singlas that derimne the cell population druing develipment.

Question 4

What are transit amplifying cells? L15 S15

Answer 4

-These cells divide frequently

Differentiating stem cell that leaves the basal layer. It has a finite amount of divisions and once it is done, all its progeny will be terminally differentiated.

Question 5

What transcription factors are essential for pluripotent stem cells? L15 S27

Answer 5

-Nanog -Oct4 -Sox2 -FoxD3

Question 6

What is the difference between hematopoietic stem cells and mesenchymal stem cells? L15 S30

Answer 6

Both found in bone marrow HSC: -differentiates into RBCs, WBCs, and platelets MSC: -differentiates into connective tissue, heart/skeletal muscle tissue, and nerve tissue

Question 7

What are induced pluripotent stem cells? L15 S41-42

Answer 7

Introduction of certain transcription factors to adult cells causing them to gain pluripotent stem cell properties High risk of teratoma formation

Question 8

What is SCNT? L15 S44

Answer 8

Egg cell has nucleus removed and is fused with and adult cell. Growth will generate pluripotent stem cells

Question 9

Adult Stem Cells are _____. How are they regulated? What function do they possess?

Answer 9

Tissue specific.

• stricly imposed by molecular restraints on gene expression
• responds to demands of growth and repair

Question 10

Stems cells are _____ they can either ____ or give rise to ___ that are more ____.

Answer 10

• primitive
• self renew
• daughter
• specialized

Question 11

Potency is also known as

Answer 11

proliferative potiential

Question 13

Adult stem cells are used for what?

Answer 13

• tissue homeostais
• they are already partially comitted thus no longer pluripotent
• unable to differentiate in a more regulated range

Question 14

How does divisonal Assymetry and enviromental assymetry matain stem cell pool?

Answer 14

• for steady pool 50% of daughter cells must reamain as stem cells
• divisonal: assymetric divison may create 2 cells, one with stem cell charatericits and other with the factor for it do differentiate (factors are methylation patterns on genes, transcripton factors)
• enviromental: divison males 2 identical cells but enviroment may stimulate one to diff

Question 15

Immoral Strand Hypothesis

Answer 15

• daughter cell will retain stem cell charaterisitcs by keeping all of OG DNA
• the cells that are going to differntia will get the new strands
• happesn to prevent genetic errors in stem cells

Question 16

Embryonic stem cells are from where?

Do they have restrictive or unrestrivtive developmental poteintial?

When they are put back into the blastocyst they can _____ well with the embryo.

They can develop into what?

Answer 16

–from blastocyst

• proliferate indef in culture (unrestricted development)
• integrate well
• develop into different types

Question 17

If enbryonic injected into an enbryo at a later stange or an adult they fail to receive appropriate sequence, gf or cues for proper differentiation. what can this cause?

Answer 17

Can give rise to teratomas or tumors.

-ES cells on theri own are incabable of generating the body plan thus are better off left in emrryos.

Question 18

If you ineject ES cells into animal and they get the right signals what can happen? What do they need?

Answer 18

They can differntiate into what ever tissue type they are directed to. ALL YOU NEED TO DO IS CULTUER THE CELLS AND PRESENT THEM IN CORRECT GF.

Question 19

ES cell therapy

Answer 19

• fertilize an egg
• take the blastocyst and remove the inner cell mass
• transplant them to the patient
• have been used to treat dm, parkisons, spinal injury, MI in mouse

Question 20

Adult Stem cells show relaxation of restrictions in an altered enviroment by what?

Answer 20

-based on GF that are localzied in specific tissues.

Question 21

Adult stem cell use in transplant

Answer 21

• they have restricted capacity and growth potiental
• can not replace emrbonyic stem cells in tissues transplants

Question 22

Where do hematopoetic and stromal stem cells come from?

Define the difference?

Answer 22

• come from BM
• HSC are blood compoents
• msc are connective tissue components

Question 23

Cord blood

Answer 23

-adlut stem cells that are undifferentiated can have banks s for familila use and other patients.

Question 24

Induced pluripotent stem cells

Answer 24

IPS cells:

Question 25

Mesenchymal cells: BM and adipose derived

Answer 25

-bone marrow derived mesenchymal stem cells (BMSC) TRANSPLANT or adipose derived mesencymal stem cells (amsc) liposection can diff in vtiro or vivo into many cells and can regenrate neuronal cells. These cells are adult stem cells. - ability to self renew - immortal

Question 26

Somatic cell nuclear transfer

Answer 26

SCNT: Combines coloing methods - take egg cell and remove the nucleus - then take a somatic cell (anything but egg or germ cell) - stimulate it - remove inner cell mass for pluripotent stem cell - culture them

Question 27

What is the one problem in SCNT

Answer 27

- its ethically wrong - need alot of oocytes

Question 28

SCNT can be used to treat what?

Answer 28

TYPE 1 DM