Heparin-binding epidermal growth factor-like growth factor, collateral vessel development, and angiogenesis in skeletal muscle ischemia.
OBJECTIVE
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a potent mitogen for smooth muscle cells and has been implicated in atherosclerosis, tissue regeneration after ischemia, vascular development, and tumor angiogenesis. We examined the hypothesis that HB-EGF participates in angiogenesis and collateral growth in ischemia.


RESULTS
During 3 weeks after femoral artery ligation, no attenuation occurred in recovery of hindlimb perfusion or distal saphenous artery flow in HB-EGF-null (HB-EGF(-/-)) versus wild-type mice. Lumen diameters of remodeled collaterals in gracilis muscle were similar by morphometry (87+/-8 versus 94+/-6 microm) and angiography, although medial thickening was reduced. Gastrocnemius muscle underwent comparable angiogenesis (41% and 33% increase in capillary-to-muscle fiber ratio). Renal renin mRNA, arterial pressure, and heart rate during anesthesia or conscious unrestrained conditions were similar between groups. These latter findings validate comparisons of perfusion data and also suggest that differences in arterial pressure and/or renin-angiotensin activity are not masking an otherwise inhibitory effect of HB-EGF absence. Four days after ligation, EGF receptor phosphorylation increased in muscle by 104% in wild-type but by only 30% in HB-EGF(-/-) mice. This argues against compensation by other EGF receptor ligands.


CONCLUSIONS
Our results suggest that HB-EGF is not required for arteriogenesis or angiogenesis in hindlimb ischemia.
Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC 27599-7545, USA.
Dan
D
Chalothorn
Scott M
SM
Moore
Hua
H
Zhang
Susan W
SW
Sunnarborg
David C
DC
Lee
James E
JE
Faber
D000818:Animals; D006332:Cardiomegaly / Q000235:genetics / Q000503:physiopathology; D004815:Epidermal Growth Factor / Q000235:genetics / Q000502:physiology*; D066246:ErbB Receptors / Q000378:metabolism; D005263:Femoral Artery / Q000502:physiology; D066257:Heparin-binding EGF-like Growth Factor; D006614:Hindlimb / Q000098:blood supply; D036341:Intercellular Signaling Peptides and Proteins; D007511:Ischemia / Q000235:genetics / Q000503:physiopathology*; D008026:Ligation; D051379:Mice; D008817:Mice, Mutant Strains; D018482:Muscle, Skeletal / Q000098:blood supply; D018919:Neovascularization, Physiologic / Q000502:physiology*; D010641:Phenotype; D010766:Phosphorylation
C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors