Wykład IV

Arteriogenic growth factors

Two classes of endothelial cell specific tyrosine kinase receptoTwo classes of endothelial cell specific tyrosine kinase receptorsrs

Jones N et al., Nature Cell Biol 2001

TieTie--1 1 and Tieand Tie--2 2 receptorsreceptors1. Endothelial cell specific tyrosine kinase receptors 2. Built of extracellualr and intracellular domains – different than

VEGF receptors 3. Expressed early in development, especially in endothelial cells 4. Tie –2 - receptor for angiopoietins

Tie –1 - ?

Knockouts of TieKnockouts of Tie--1 1 and Tieand Tie--2 2 receptorsreceptors

Tie-1-/- - die between E13.5 and E18.5- normal development up to E13.0; then local hemorrhage, edemarupture of microvessels

Tie-2-/- dies at E10.5 – cardiac failure, hemorrhage, other vascular defects Embryos have low number of endothelial cells, lack of smooth muscle cells

Angiopoetyny Angiopoetyny

Jones N et al., Nature Rev Mol cell Biol 2001

Ang-1

1. Ligand for Tie-2

2. Does not induce endothelial cell proliferation, but is required for their survival

3. Expressed in the myocardium and perivascular cells

4. It is not strongly upregulated

5. Ang-1-/- - defects similar to Tie-2-/-

Modulation of apoptosis of endothelial cells Modulation of apoptosis of endothelial cells

Dimmeler & Zeiher, Circ Res 2000

Central role Central role of of Akt Akt kinase in angiogenesis signalingkinase in angiogenesis signaling

Dimmeler & Zeiher, Circ Res 2000

Role of VE-cadherin in angiogenesis

Disruption of VE-cadherin impairs angiogenesis – knockouts die at E9.5

Carmeliet et al., Cell 1999

AngAng--221. Ligand for Tie-2 - antagonist of Ang –1 in some cells

- but in others – can phosphorylate Tie-2

2. Expressed at low level by endothelial cells, but is strongly upregulatedat sites of active vascular remodeling - ovary, tumors

3. Upregulates at times of both vessel growth and regression – thus Ang-2 plays an active role in blood vessel remodeling

4. Ang-2- -/- - born relatively normal, but many die at 14 day –- defects in remodeling of the vessels

5. Transgenic overexpression of Ang-2 disrupts blood vessel formation

Expression of angiopoietin-1 and angiopoietin-2 in various tissues

Role Role of of Ang1 Ang1 and and Ang2 Ang2 in angiogenesis in the ovary in angiogenesis in the ovary

Thurston F, Cell Tissue Res 2003

Increased Vascularization in Mice Overexpressing Angiopoietin-1

Overexpression of Ang-1 in the skin of transgenic mice

Suri et al, Science 1998

StrongStrong VEGF VEGF expression induces massive edema expression induces massive edema –– VEGF VEGF is alsois also a a vascular permeability factorvascular permeability factor

massive edemaafter VEGF Thurston et al., Science 1999

Thurston et al., Science 1999

Thurston et al., Science 1999

Early development Late development &Adult

VEGF endothelial cells Ang1 vessel maturation differentiation (agonist) & stabilizationproliferation tube formation

Ang2(antagonist)

vessel de-stabilization

+ VEGF No VEGF

Adult neovascularization Vessel Regression

Factors involved in arteriogenesis Factors involved in arteriogenesis –– Ang1, PDGFAng1, PDGF--BB, TGFBB, TGF--ββ11

Arteriogeneza Arteriogeneza ––-- krążenie oboczne krążenie oboczne

Formation of blood vessels in adultsFormation of blood vessels in adults

Carmeliet, Nature Med. 2000

Arteriogenesis in collateral development Arteriogenesis in collateral development –– involvement of endothelial involvement of endothelial cellscells, , smooth muscle cells and monocytessmooth muscle cells and monocytes

Waltenberger 2001, Circulation

Role Role of of VEGFRVEGFR--1 1 in arteriogenesis in arteriogenesis

Waltenberger 2001, Circulation

Role Role of of VEGFRVEGFR--1 1 in arteriogenesis in arteriogenesis –– impairment in diabetes impairment in diabetes

Waltenberger 2001, Circulation

Ephrins Ephrins

Change of paradigm in angiogenesis research Change of paradigm in angiogenesis research

Augustin & Reiss, Cell Tissue Res, 2003

Ephrin receptors and ephrin ligands Ephrin receptors and ephrin ligands

Augustin & Reiss, Cell Tissue Res, 2003

Possible sites and mechanisms of Eph/ephrin action

RH Adams & R Klein, 200

Ephrin and Eph receptors reverse signaling Ephrin and Eph receptors reverse signaling inhibition of vein outgrowth and proliferation

angiogenic sprouting and outgrowths of the arteries

Torres-Vazquez et al., Cell Tissue Res, 2003

CrossCross--talk talk between ephrinBbetween ephrinB--EphB4 EphB4 and and VEGF/Ang1VEGF/Ang1VEGF Ang1

MAPKEphrin Ephrin B2B2 PI3K kinase

Akt

EC proliferation EC survival

Gene Survival Phenotype

VEGF-A E10.5 impaired vasculogenesisimpaired angiogenesisimpaired vessel organization

VEGF-B Alive atrial abnornamality

VEGF120/188 Alive impaired arterial development

VEGF120/164 Alive impaifred arterial development

VEGF164/188 Death impaired myocardial angiogenesispostnatally ischemic cariomyopathy

PlGF Alive impaired pathological angiogenesis

VEGFR-1 E8.5 disorganized EC

VEGFR-2 E8.5-9.5 absent yolk sac blood islandreduced hematopoietic precursors

VEGFR-3 E9.5 enlarged vessel lumens, cardiovascularfailure

Gene Survival Phenotype

Eph B2/3 E11.5 defects in vasculogenesis and angiogenesis

Ephrin B2 E9.5 defects in angiogenesis- impaired arterial and venous capillary network

Pdgf-b E17.5-E18.5 lack of pericytes, microvascular aneurysms

Ang-1 E10.5 dilated vessels, impaired vessel branching

Ang-2 Alive impairement of vascular bed in the retina

lymphatic defects

Tie –1 E13.5-E14.5 leaky vessels, edema

death immediate after birth

Tie-2 E10.5 dilated vessels, impaired vessels branching

Role Role of coagulation factors in angiogenesis of coagulation factors in angiogenesis

Tissue factor

-a 47-kDa transmembrane protein

-receptor for factor VIIa

-interaction of TF with factor VIIa provokes the sequential activation of factor IX and factor X

-TF expression is induced by VEGF: in monocytes and in endothelialcells

Knockout of tissue factor impairs vessel maturation Knockout of tissue factor impairs vessel maturation

Carmeliet et al., 1997

Role of tissue factor and factor VII on vessel development

Plasminogen Plasminogen system system and angiogenesis and angiogenesis

Role Role of plasminogen of plasminogen system system in in VEGFVEGF--dependent dependent angiogenesis angiogenesis

VEGF

VEGFR-1

eNOS

NO

uPA

angiogenesis

Role Role of uPA in matrix degradation of uPA in matrix degradation –– positive and destructivepositive and destructive

Matrix metalloproteinasesMatrix metalloproteinases

Vascular integrins Vascular integrins

A large number of vascular cell surface glycoproteins that functionas cell adhesion receptors to extracellular matrix and sometimes

in cell-cell adhesion

Integrins Integrins

Stupack and Cheresh, Science STKE, 2002

ProPro-- and antiand anti--angiogenic angiogenic role role of of ααvvββ33 integrin integrin

Fibroblasts growth factors Fibroblasts growth factors

-23 FGF family members and 4 tyrosine kinase receptors-Stimulate endothelial cell proliferation, migration and differentiation- involved in tissue repair, wound healing - involved in tumor angiogenesis

- Similarities and differences between VEGF and FGFs- requirement for angiogenesis - mechanisms of release- mechanisms of signal transduction

Role still uncertain

Fibroblasts growth factors Fibroblasts growth factors

Fibroblasts growth factor receptors Fibroblasts growth factor receptors

FGF FGF action action on on endothelial cells endothelial cells

Children's Hospital. Surgical Research.300 Longwood Avenue, Boston, MA 02115 USA.

Created by Karim Awad.

Fibroblast growth factor and angiogenesis

Binding of FGF results in receptor dimerization and the phosphorylation of specific tyrosine residues within the intracellular domain of thereceptor (the positions of phosphotyrosine residues in the receptor amino acid sequence are shown). Several intracellular signalling proteins are activated either directly via receptor binding, such as Crk and PLC-, or via indirect mechanisms, such as Shc and FRS-2. Several other proteins, such as Src, Shb, p38 MAPK, PI3K, p70 S6K and Grb14 are also activated via FGFR-1, although their exact mechanism of activation has not been determined (indicated by?).

Cross MJ, Claesson-Welsh L, 2001

Summary of the mechanisms of angiogenesis