L5 - Gut Organoids Flashcards
What is one of the best described niches
Crypt niche in the intestin
Describe the morphology of the crypt niche
Tube of cells aranged on the BM
Stem cells in the basal region with paneth cells either side
Portion of BM specialised in the region of the stem cells
Stem cell progeny TRANSIT AMPLIFYING CELLS move upwards and differentiate
Underlying mesenchymal cells (green) send signals to which help regulate stem cell activity
Stem cells (CBC cells) were identified through the expression of …..
Wnt target gene LGR5
What surrounds the LGR5+ cells
Paneth cells
What are LGR5+ cells
Stem cells expressing the Wnt target gene LGR5
What signalling molecules are expressed at high levels in the ventral portion of the crypt
Wnt and Notch
Also have Noggin and Gremlin
What signalling molecules are expressed at ghifher levels dorsally
BMP PTEN Ihh
Spatial gradients of what 3 signalling molecules are set up along the crypt axis
Wnt
BMP
EgFG
What are EGF notch and Wnt essential for
Stemness
What is the effect of BMP on stemness
Repression of stemness
Where do the signals Wnt, EGF and notch come from
Paneth cells
What would be the purpose of making a LGR5-EFGP mouse
To see where LGR5 is being expressed
Describe how a LGR5_EGFP reporter line would be established
Express GFP under the control of thr LGR5 enhancer elements at the 5’ region of the Lgr5 gene
Describe how flourescently activated cell sorting may be used to make mini guits
Make LGR5+ CBC cells labelled with GFP
Machine sorts out cells flouresing so end with a culture of pure LGR5+ cells
Can be used to make organoids
Single cell forms symmetrical cyst
Symmetry broken by bu formation
What are the uses or gut organoids
Cell therapy
After colon cancer urgery where region of bowel cut out - leaves big scar
Scar can be seeded with organoids from the LGR5 CBC stem cells - fanatastic recovery in mouse
Leads to the resoration of the villi structure
