Stem cells

Question 1

Embryonic stem cells

Answer 1

• From blastocyst
• Can proliferate indefinitely
• Unrestricted developmental potential
• Can become any cell of organism (even into germ cells)
• If injected into an embryo at a later stage or into an adult, they don’t get the right sequence of cues that is needed for differentiation
• Often become tumors when injected in

Question 2

Can embryonic stem cells be put back into the embryo?

Answer 2

Yes

Question 3

Teratomas

Answer 3

Come from embryonic stem cells

Tumors can have teeth, other body parts (b/c ES cells aren’t able to generate body plan)

Question 4

Transformation

Answer 4

Normal cell starts to divide inappropriately—into cancer

Question 5

Embryonic stem cells come from where?

Answer 5

Inner cell mass of blastocyst

Can’t be put back into unfertilized egg to become organism

Question 6

ES cells

Answer 6

Can be derived from human embryos

Can be coaxed to differentiate into different cell types

Can be injected into adult organs to replace damaged parts

Been used successfully in brain

*we don’t want to inject a completely undifferentiated ES cell

Question 7

Different Cell Types from ES cells

Answer 7

We try and culture them outside the blastocyst, get into lineage that is safer and inject directly to site of damage

Question 8

How to get cultured embryonic stem cells to become neurons?

Answer 8

Use retinoic acid (steroid hormone)

Can trick cells into turning on certain TF’s

Question 9

Cell types in nervous tissue are usually derived using what?

Answer 9

Use fibroblast growth factor

Question 10

Easiest way to induce embryonic stem cells to turn into different tissues?

Answer 10

Chemicals

Question 11

How are ES cells derived?

Answer 11

Grow on culture or leave it alone and becomes organism

Question 12

Human ES cell growth

Answer 12

Fibroblasts help create happy medium for cells

Plate blastocysts and then bring in the blastocyst cells

Question 13

Isolation of Embryonic Stem cells

Answer 13

When we differentiate the cells in culture they will be heterogeneous and we want to identify homogenous populations

Question 14

Nerve and muscle cells are found in a complex mixture when growing them. Why?

Answer 14

Because retinoic acid stimulates both

Question 15

Application of ES cells

Answer 15

Can solve rejection problems

Question 16

Founder cells are ______

Answer 16

Multipotent

Derived to make a certain type of tissue (heart founder cell, liver founder cell etc)

They divide, giving rise to daughter cell which will remain a stem cell and to a transient amplifying cell

Liver damage→founder cell will be used

Question 17

Mature stem cell

Answer 17

Pro: Probably came from your own cells

Con: Get to level of senescene pretty quickly

Question 18

Early stem cell

Answer 18

Immortal, continue to grow

Potential for rejection

Question 19

Somatic cell nuclear transfer

Answer 19

Nucleus taken from somatic cell of patient and injected into oocyte of a donor replacing the oocyte nucleus

First step in closing

Solve immune rejection b/c you’d use your own genome

Question 20

Challenges for Regenerative Medicine and Transplantation Therapy

Answer 20

• Production of required cell type in sufficient numbers and pure form
• What cell to transplant
• Delivery and proper integration
• tissue/immune rejection
• Embryonic- or fetal-derived grafts may be immunogenic
• Some transplantation sites may be immunologically privileged

Question 21

Adult stem cell problems

Answer 21

Immune rejection

Question 22

Outside manipulation of adult stem cells can reprogram them

Answer 22

True

Question 23

Strategies of regenerative medicine

Answer 23

Induced
Reprogramming
Somatic cell transfer

Question 24

Adult stem cells that we can take out of body and manipulate and put back in

Answer 24

Bone marrow
Skeletal muscle
Heart muscle
Skin

Question 25

Bone marrow stem call can become

Answer 25

Every blood cell that we need Can also become other tissue

Question 26

Adipose derived stem cells

Answer 26

People have successfully made them into different kinds of cells

Question 27

Basal layer of many tissues (gut, epithelial) is where you have dividing stem cells, adult derived

Answer 27

True Basal stem cells

Question 28

Basal layer

Answer 28

Has stem cells. They divide to maintain the basal layer and also supply cells that move to other layers, undergo change in gene expression and differentiate

Question 29

Stem cells provide an indefinite supply of fresh differentiated cells

Answer 29

True

Question 30

Cells that cross the basal lamina can become what?

Answer 30

Metastatic tumors

Question 31

Olfactory Neurons

Answer 31

Lining of nose is epithelium Adult stem cells give rise to these cells

Question 32

Olfactory receptors

Answer 32

- Free surfaces of cilia have odorant receptor proteins - A type of G-protein coupled receptor - Each neuron expresses only one of these genes

Question 33

What you smell is biscuits and gravy

Answer 33

That has one receiving signal and one axon

Question 34

Example of Adult Stem Cell Therapy

Answer 34

Bone marrow transplants

Question 35

Fibroblasts (skin sample)

Answer 35

Induced pluripotent stem cells-they go back to embryonic stem cell state so that they can become every tissue

Question 36

Our bone marrow contains many different stem cells

Answer 36

True Mesenchymal cells (can get to brain and fix brain damage)-they can become neuronal-like cells Some adult stem cells can become multiple lineages (from adipose too)

Question 37

Somatic Cell Nuclear Transfer (SCNT) How to avoid ethical dilemma

Answer 37

We take unfertilized egg and remove nuclei from somatic cell (skin cell for example), it's your genome, put it into egg and start developmental process, then use blastocyst cells to put into dish, turns into pancreatic beta cells into pancreas and you won't have rejection problems Reprograming without having to go through embryo step

Question 38

Other uses for SCNT

Answer 38

We can analyze potential toxins to our body by using cells that are made from our body We can take a diploid genome, put it into an egg and get life. Big finding b/c it opened up its genes that were in heterochromatin and now it's an embryonic stem cell

Question 39

Induced pluripotent stem cells (iPS)

Answer 39

Inject pluripotent genes into adult stem cells Somatic cells can be reprogrammed to induced pluripotent stem (iPS) cells by defined, limited sets of transcription factors Taking cell that has gone through many divisions and trying to get it back to the embryo

Question 40

Problems with all these dividing cells

Answer 40

Genetic drift and cell growth

Question 41

3 different protocols used for ES cell differentiation

Answer 41

As embryoid bodies Differentiated on stromal cells On extracellular matrix proteins

Question 42

Regeneration of olfactory receptor cells is one of the only | few instances of adult neurogenesis in the CNS.

Answer 42

True

Question 43

Adipose and bone marrow have shown the ability to differentiate in vitro and in vivo into to chondroycytes, myoblasts, osteoblasts, pancreatic betacells and neuronal-like cells

Answer 43

True

Question 44

Adult stem cells (bone marrow) can regenerate neuronal cells in the brain

Answer 44

True

Question 45

Reprograming

Answer 45

Inject proteins from pluripotent cell into adult stem cell

Question 46

Somatic cell + Embryonic stem cell=

Answer 46

Cellular fusion--> pluripotent hybrid cell--> blood cells or neural cells

Question 47

Stem cell- key phrase

Answer 47

Self-renew

Question 48

Undifferentiated, differentiated etc Stem cells (pluripotent) Adult stem cells (multipotent) Quiescent stem cells

Answer 48

Stem cells (pluripotent): undifferentiated Adult stem cells (multipotent): slightly differentiated Quiescent stem cells: fully differentiated

Question 49

Immortal strand hypothesis

Answer 49

ALL of original daughter strand chromosomes go into the daughter cell, they all line up on one side during mitosis (thanks to signaling at kinetochores)

Question 50

Embryonic stem cells: types | found in embryo

Answer 50

Totipotent (from zygote-->whole organism) Pluripotent: inner cell mass, blood cells, cardiac muscles, neural cells etc, can be grown indefinitely, main one used in research

Question 51

Adult stem cells | found in many organs

Answer 51

Multipotent Specializing potential is limited to one or more cell lines e.g. Mesenchymal stem cell --> Bone or cartilage or connective tissue etc Tough to grow

Question 52

iPS cells

Answer 52

Take normal cell (e.g. skin cell), give it genetic instructions in dish, they can reverse and be able to be any cell and become pluripotent Skin cell-->iPS cell--> Blood cell Good for tissue regeneration, genetic matches for tissues,