Angiogenesis Flashcards

Question

Give the basic stages of vasculogenesis

Answer 1

Haemopoietic stem cells --> haemangioblast --> endothelial progenitor cells --> vasculogenesis --> angio/arteriogenesis --> mature vasculature

Answer 2

Circulating endothelial progenitor cells are present in humans which if the correct signals are present - can form new blood vessels. A lot of literature on this regarding repair of damaged tissue. Previously believed only angiogenesis was able to occur post-birth.

Answer 3

Aortic valves should be avascular, however during thickening and calcification - monocytes and macrophage infiltration occur which drives neovascularization making the aortic valve vascular.

Answer 4

It doesn't activate intracellular signalling and acts as a VEGF sponge - this is because it doesn't have a tyrosine kinase attached intracellularly therefore it binds to VEGF to prevent it binding to the membrane VEGFR and therefore prevent angiogenesis. This shows that even cornea cells produce VEGF

Answer 5

Manatee - vascularised corneas

Answer 6

Decreases - resulting as an increase in vascularization

Answer 7

Cell apoptosis and then an inflammatory response of macrophages to sweep up the debris.

Answer 8

Endothelial-derived heparin binding EGF-like growth factor (HB-EGF) was shown to mediate this process by signaling via ErbB1 and ErbB2 receptors in SMCs to recruit them.

Answer 9

Raised SHB-EGF in vivo - bladder in humans resulted in an increase in growth rate, colony-forming ability, and activation of cyclin D1 promoter, as well as induction of vascular endothelial growth factor and MMPs

Answer 10

The process of VM is caused by tumour cells assuming an endothelial-like phenotype with no help from pre-existing host endothelial cells suggesting the process is vasculogenic in nature.

Answer 11

Matrix rich structures in laminin (basal lamina substance) in nest or lobule shaped closed loops.

Answer 12

Breast Ovarian Prostate Lung GBM

Answer 13

In early stages, angiopoietin-2 is released which triggers the promotion of endothelial activation, destabilization, and inflammation. Overtime, the tumour grows and angiopoietin-2 increases resulting in a loss of endothelial integrity which causes tumour hypoxia and therefore the recruitment of VEGF and therefore start the formation of vessels

Answer 14

Seen that the loops formed in tumour angiogenesis increased when exposed to vatalanib because the vessels undergo VM in response to hypoxia induced by vatalanib. Making GBM a lethal and resistant disease in regards to biologic treatment

Answer 15

Poorly understood but discovered due to anti-angiogenic therapy resistance and a worse prognosis.

Answer 16

showed a predominant enrichment in matrix-remodeling macrophages. Based on their expression signature of genes involved in matrix degradation and deposition, we speculate that this macrophage subtype might be able to assist invasive cancer cells to co-opt healthy lung vessels. For co-opting cancer cells to travel alongside pre-existing blood vessels, they must make their way through the interstitial stroma, which is dense in ECM. Matrix-remodeling macrophages might assist co-opting cancer cells by paving the way through matrix reorganization, involving degradation of the existing matrix (facilitating invasion by cancer cells) and deposition of the new matrix (anchor points for invading cancer cells). This hypothesis is further supported by our findings that these macrophages were located at the invasive forefront of co-opting metastases, where blood vessels become co-opted by cancer cells.

Answer 17

Old women underwent an 8 week cardiointensive programme to determine if their low levels of VEFG in their myocytes and low VEGF release could be increased - did not significantly increase therefore - the findings indicate that aged women have a reduced potential for capillary growth in skeletal muscle which, with ageing,

Answer 18

Exercise results in very low O2 levels in the muscle which the hypoxia stimulates VEGF

Answer 19

VEGF is needed during placental development. High levels of solube VEGFR1 were seen in pre-eclampsia. Study was done to look at the levels of SVEGFR1 in mothers per week of gestation to determine if theres a link and if this canbe monitored for rationalising management plans. Placenta showed very high levels of sVEGFR-1. This suggests that sVEGFR1 is restricting VEGF from doing its role and resulting in a dysregulation of angiogenesis and hypertension

Answer 20

revealed the significant upregulation of sVEGFR-1 levels as the severity of disease increases from GH to eclampsia (both early- and late-onset of the disease) as compared with gestationally matched controls. Hence, sVEGFR-1 is a reliable tool to discriminate between different types of pregnancy-related hypertensive disorders.

Answer 21

Increases level of VEGF due to hypoxia Increase in mRNA to make VEGFR1 and 2 to increase muscle responsiveness to VEGF

Answer 22

capillaries develop into small arterioles; thus capillary angiogenesis potentially contributes to increased blood flow by providing a source of new arterioles.

Answer 23

VEGF-C, a ligand of the VEGFR-2 and VEGFR-3 receptors, activates blood-vessel tip cells - at new vessel formation

Answer 24

VEGFR-3 is necessary for the formation of the blood vasculature during early embryogenesis, but later becomes a key regulator of lymphangiogenesis — the formation of new lymphatic vessels from pre-existing ones

Answer 25

Can inhibit VEGFR2 dimerization or ligand binding through its antibodies which slows tumour progression so may have a role as an antiangiogenic candidate

Answer 26

To stabilize endothelial cell channels, angiogenic endothelial cells release PDGF-B to chemoattract PDGF receptor-β (PDGFR-beta) pericyte

Answer 27

causes vessel leakage, tortuosity, microaneurysm formation and bleeding

Angiogenesis Flashcards

(51 cards)