Reduced vascular endothelial growth factor expression and intra-epidermal nerve fiber loss in human diabetic neuropathy.
OBJECTIVE
To assess the relevance of vascular endothelial growth factor (VEGF) in the maintenance of peripheral nerve integrity in diabetic neuropathy we have assessed the expression of VEGF and intra-epidermal nerve fiber density (IENFD) in skin biopsy samples from diabetic patients.


METHODS
Fifty-three diabetic patients and 12 nondiabetic control subjects underwent neurological evaluation, electrophysiology, quantitative sensory, and autonomic function testing. Dermal blood flow responses were evaluated with laser Doppler flowmetry. Skin biopsies were performed on the dorsum of the foot, and IENFD was quantified and compared with the expression of vascular endothelial growth factor A (VEGF-A), its receptor vascular endothelial growth factor receptor 2 (VEGFR-2), hypoxia-inducible factor 1alpha (HIF-1alpha), and microvessel density.


RESULTS
IENFD decreased progressively with increasing severity of diabetic neuropathy (P < 0.001). The dermal blood flow response to acetylcholine was reduced in diabetic patients with mild and moderate neuropathy (P < 0.01), and the intensity of staining for epidermal VEGF-A was significantly reduced in diabetic patients compared with control subjects (P < 0.01). Epidermal HIF-1alpha and VEGFR-2 expression did not differ between groups.


CONCLUSIONS
Progressive endothelial dysfunction, a reduction in VEGF expression, and loss of intra-epidermal nerve fibers occurs in the foot skin of diabetic patients with increasing neuropathic severity.
Quattrini
Cristian
C
Division of Cardiovascular Medicine, University of Manchester and Manchester Diabetes Centre, Manchester Royal Infirmary, Manchester, UK.
Jeziorska
Maria
M
Boulton
Andrew J M
AJ
Malik
Rayaz A
RA
D001706:Biopsy; D003929:Diabetic Neuropathies / Q000473:pathology*; D005528:Foot; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology* / Q000502:physiology*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply / Q000166:cytology / Q000294:innervation / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D042461:Vascular Endothelial Growth Factor A; D040262:Receptors, Vascular Endothelial Growth Factor