Lecture 16 - Stem cell therapies for resp. disease

Question 1

The lung epithelium is derived from _________

Answer 1

endoderm

But there are cells from all 3 germ layers - innervation from ectoderm for instance

Question 2

There are over __ different cell types in the adult lung

Answer 2

50

lots of different mesenchymal, epitheliual, bood, nerve cells

Question 3

The lung epitthelium is formed by proliferaion of an ________ progenitor cell in the ____ ________

Answer 3

The lung epitthelium is formed by proliferaion of an endodermal progenitor cell in the foregut endoderm

Question 4

The structure of the lung is then formed by formation of an epithelial lung bud, surrounded by loosely packed ________ ____

Answer 4

mesenchymal cells

Question 5

What are the 5 stages f lung develpoment

Answer 5

embryonic

pseudoglandular - bit more branching

canalicular - more complex branching

saccular - alveolar start to form

alveolar - seperation of aleolar for better gas exchange (continues beyond birth)

Question 6

The stem cells that give rise to all the epithelial branching is a small bunch that reside ..

Answer 6

at the tips of the lung stem - the fetal lung epithelial stem cells

Question 7

The Mesenchymal cells derived from splanchnic mesoderm give rise to what in the developing lung

Answer 7

fibroblasts and smooth muscle

Question 8

The proliferation and differentiation of lung embryonic stem cells is ergulated by signals emanating from …

Answer 8

the surrounding mesenchyme

Question 9

The innervation of the developing lung is derived from…

Answer 9

neural crest progenitor cells in the ectoderm

Question 10

The vascularisation of the developing lung is derived from…

Answer 10

endothelial progenitor cells of the mesoderm

Question 11

New evidenece shows that lung mesemchyme and endothelium shares a common ancestor with…

Answer 11

the cv system

Question 12

Flow cytometry

Enzymes can be used to break down the lung tissue to singe cells, then can select cells and look at whether they can proliferate and differentiate - what the advantages of this for stem cell research?

Answer 12

The ‘single cell’ measuring principle: each and every cell is analysed as a single event; rare populations can be detected

Question 13

in the adult lung there are stem cells with multi-linage potential, meaning…

what else is there?

Answer 13

They can differentiate into airway and alveoli epithelial lineages

There are also progenitors that are lineage restricted (generate only alveoli or airway cells)

Question 14

There is definitely a progenitor cell hierarchy in which part of the lung?

Answer 14

epithelium

Question 15

(cHECK out the scematic diagram)

Answer 15

.

Question 16

Epithelial stem cell fate and lineage preference is determined by..

Answer 16

Microenvironment

Question 17

Lung mesenchymal stromal cells interact directly with epithelial cells and create…

Answer 17

a niche for epithelial stem cells in culture

Question 18

Adult lung progenitor cells can be isolated on the basis of the differential expression of..

Answer 18

EpCAM and CD24

Question 19

What is a powerful tool for the analysis of lung stem/progenitor cell organisation and regulation?

Answer 19

In vitro clonogenic assays

Question 20

In vivo-lineage tracing techniques enable the identification of…

Answer 20

lineage hierarchies

Question 21

True or False

Different stem cells are required to maintain each of the different germ layers

Answer 21

True

Question 22

Stem cells are defined in context. The deregulation of the micro-environment can effect…

Answer 22

the homeostasis of epithelial stem cells and contribute to lung disease

Question 23

lung disease is ranked what for mortality, incidence, prevalence and cost?

Answer 23

2nd

Question 24

COPD is ranked what in global burden of disease

Answer 24

3rd

Question 25

Different diseases are going to take different approaches and possibly different stem cells depends on the …

Answer 25

nature, severity and timing

Question 26

What is a common therapeutic objective for differnet lung diseases?

Answer 26

regeneration of epithelia

reduce inflammatory milleu

inhibit mesemchymal/smooth muscle

Question 27

Congenital lung hypoplasia is what?

Answer 27

lung is underdeveloped

need to regenerate everything

Question 28

Inchronic respiratory diseases the injury repair process goes wrong lead to ..

Answer 28

A) lack of repair

B) too much proliferation of endogenous stem cells which can lead to hyperplasia and cancer.

Development of drugs which switch on/off adult lung stem cells will offer the ability to correct the endogenous regeneration and repair process

Question 29

In some cases the intrinsic potential of stem cells may be affected by the disease, while in other cases ..

Answer 29

the microenvironment may be damaged.

Question 30

What are the challenges of stem cell transplants for lung regeneration?

Answer 30

What source of stemc ells to use

Lung epithelial stem cells delivered to a ‘diseased’ lung may not receive adequate signals for ‘healthy’ lung regeneration. If the microenvironment is also damaged, the fate and specificity of the exogenous stem cells may be altered.

Question 31

How can the micro-environment be reconditioned to make it suitable for SC transplantation?

Answer 31

good question… don’t think there’s’ an answer

Question 32

What are some sources of SCs for therapy?

benefits and drawbacks for each

Answer 32

Embryonic stem cells

induced pluripotent SCs (iPS) - autologous, but have modified cell so need to make sure it’s still safe

Safest - Adult stem cells, proliferative potential is less than the others

Question 33

Stem cells can be used as a vehicle for gene therapy

Expansion of stem cells in vitro provides an opportinity to correct what?

Answer 33

the genotype of patients with CF.

Lung stem cells could be engineered with a correct copy of the CFTR gene and transplanted back into patients to replace the “diseased” epithelium with “normal” epithelial cells

Question 34

What are the challenges for Stem cells being used as a vehicle for gene therapy

Answer 34

engraftment of stem cells in the lung epithelium is often very poor

Question 35

Seeding stem cells onto decellularised trachea scaffolds has been successful in the clinic for replacement of ..

Answer 35

injured trachea - formed a viable piece which was transplanted

easy because its a single layer of epithelial cells.

need to check the cilia are beating the right way though!

Question 36

What are the key questions for lung stem cells therapies?

Answer 36

What are the endogenous lung stem cells that maintain the lung throughout adult life

How do we isolate adult lung SCs

What are the regualtors of proliferation and differentiation in adult lung SCs

How do we drive embryonic SCs or iPS cells to differentiate into lung cells

Question 37

In summary what are the potential clinical uses of stem cells for respiratory diseases?

Answer 37

Regenerative medicine - cellular therapy and regulation of endogenous stem cells

Bioengineering - breathing now life into old lungs

Gene therapy - cystic fibrosis

Immunimodulation - mesenchymal stem cells