L16-17: Vasculature Development Flashcards

(45 cards)

1
Q

Are signalling pathways in veins and arteries different?

A

No.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does ephrin B2 signalling do?

A
  • promote directional cell migration and invasion

- suppress cell apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is angiogenesis and vasculogenesis?

A

Vasculogenesis is formation of new blood vessels

Angiogenesis is branching from existing vessels to create new ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cell transitions in becoming blood vessels

A

mesoderm > hemangioblasts > angioblasts > endothelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is extraemryonic vasculogenesis taking place?

A

in the yolk sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is intraembryogenic vasculogenesis taking place?

A

dorsal aorta and vessels between organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the steps in vasculogenesis?

A
  1. condensation
  2. Differentiation
  3. epithelialization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What inhibits the proliferation of endothelial cells?

A

contact with the capillary basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some markers of quiescent endothelial cells?

A

PECAM, L-selectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some markers of angiogenic endothelial cells?

A

TFG-β receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three types of endothelial cells? Where are they found

A

continuous. muscle, brain, heart

fenestrated, discontinuous. endo/exocrine organs. for easier transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what the big difference between discontinous and continous/fenestrated endo cells

A

No basal membrane on discontinuous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some support cells that wrap around the endothelial cells?

A

pericytes and other mural cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What connects mural cells to endo cells?

A

angiopoetins on mural cells and Tie2 receptors on endo cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What type of cell give rise to endo and mural cells?

A

vascular progenitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which VEGFR can exist in free soluble but inactive form?

A

VEGFR1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which receptors can bind VEGFA?

A

VEGFR 1 and 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which VEGFR is not necessary in angiogenesis?

A

VEGFR 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What would happen without mural cells?

A

severe edema. makes sense because there would vasodialation without control?

20
Q

What is interesting about VEGFR1 role in vasculogenesis?

A

Even without the kinase domain, it had no negative effect on vasculogenesis. But total removal results in lower vasculogenesis.

21
Q

What is the primary role of VEGFR1?

A

Recruit macrophages to release

22
Q

What is essential for vasculogensis and what is not?

A

VEGFR2 and VEGFA is.

VEGFR1 is not

23
Q

What are three functions of VEGFR2?

A

proliferation, survival and motility

24
Q

Describe how boyden chamber assay works

A

Plate cells. Put chemoattractants and see the migration of the cells above or below the plate

25
VEGF in angiogenesis. What does it do?
- FAK pathway > stress fibre and focal adhesion > cell migration towards VEGF source - cell proliferation - tube formation
26
What part leads to the formation of vascular tube?
intracellular vacuoles
27
Difference between VEGF and bFGF?
VEGF is specific for endo cells. bFGF is not.
28
What is non sprouting angiogenesis and how does it happen?
fibroblasts wrap around the vessels to form pillars and split in half.
29
What kind of remodelling can be done during angiogenesis? How?
splitting and removal of vessels. Through pillar formation
30
What process ensures that only one cell becomes tip cell?
lateral inhibition
31
Explain lateral inhibition
Single cell with many delta binds to multiple cells with notch. This inhibits all cells with notch. So only one cell produces VEGFR2 and migrates
32
How are veins and arteries merged together?
EphB4 on veins and Epherin B2 on arteries. Reverse signalling.
33
Describe reverse signalling on eph pathway
On the ligand side, the signalling downstream happens.
34
What happens in forward and reverse signalling in eph pathway for angiogenesis.
forward. Repulsion | Backward. cell migration
35
Which direction of eph signalling defines the boundaries between arteries and veins?
forward
36
How do tumors abuse eph signalling?
overproduce ephB4 to form more arteries towards it.
37
How far is every cell from a capillary?
50-100μm
38
Does angiogenesis happen during injury?
ya. duh
39
What happens in hypoxia? Details
hypoxia > HIF1α is not degraded > binds with β > becomes a transcriptional factor > VEGF
40
How is angiogenesis basal membrane breakdown possible?
MMP
41
What are two types of MMP and what they break down
MMP2(gelatinase A) - collagen I, IV, V, fibrillar collagen MMP9(gelatinase B) - collagen IV, V
42
Are MMPs pro or anti angiogenic?
both
43
How does VEGF increase permiability?
VEGF > Fak > bind to cadherine > βcatening released > no adherens junction
44
Explain how MMPs are anti angiogenic
- can increase competition for MMP2 | - cleave ligand binding domain of VEGFR1
45
Explain how MMPs are pro angiogenic
- basal membrane disintegration - MMP2 bind to integrins - release more VEGF - cleavage of VE-cadherins - release bFGF and activate TGFβ