Adult Stem Cells in the gut Flashcards
List some of the main stem cell niches found in the body
Ovaries, testes, bone marrow, intestinal crypt and hair follicles
Which common signalling pathways do they use?
BMPs, Nanos and Wnt
Give examples of where stem cells could be applied
In the brain eg after stroke and alzheimers Baldness and missing teeth Wound healing Bone marrow transplantation (already established) Spinal cord repair after injury Blindness and deafness Types of arthritis Diabetes and Chrohn's disease
Describe how stem cells could treat multiple sclerosis?
The treatment rebuilds the patients immune sytsem
Uses stem cells from their own bone marrow to resit it to a point before it causes MS
The trials show good results
What is stem cell tourism?
Where patients are travelling to other countries with fewer restrictions to receive experimental stem cell tratement
This could be dangerous
Often advertised on websites that go beyond the scope of available treatment
Treatments can cost around $21,500
If stem cell treatment is to be used what do we have to ensure so it doesn’t cause cancer?
How to prevent self renewal
Desrcibe where gut stem cells are located
The gut is lined with villi which associate with a crypt
There is a stem cell niche in the crypts
In the gut crypt where are dividing and differentiating cells?
Dividing cells are at the distal end
Dividing cells are at the proximal end
What do Paneth cells express?
Wnt - the stem cells selectively express target gene Lgr5 when Wnt binds to these cells
Which genes determine stemness?
EGF, notch, and Wnt
If BMP binds to the stem cells what happen?
It upregulates Smad 1/5/8 which acts to promote differentiation and inhibit stemness
How can you identify which cells in the crypt are stem cells in mice?
The stem cell upregulates LGR5 when Wnt binds to it
You could therefore make a transgenic mouse where the LGR5 promoter is upstream in the pathway of GFP expression
LGR5 expressing cells will therefore shine green
What can you use the gut stem cells for?
To make mini by growing the stem cells in culture
They grow in to an organoid because they self renew but are also capable of making their own architectural integrity
How can fluorescent cells be sorted from ones that are not?
Using a fluorescent activated cell sorter (FACS)
What do organoids adhere to?
de-epitheliased wound beds caused by disease or injury
