Angiogenesis: the major abnormality of the keratin-14 IL-4 transgenic mouse model of atopic dermatitis.
OBJECTIVE
Angiogenesis plays an important role in psoriasis, but its role in atopic dermatitis is unknown. The authors examined the dermal microvasculature of an IL-4 transgenic mouse model of atopic dermatitis to determine whether angiogenesis was present.


METHODS
Transmission and scanning electron microscopy and confocal microscopy studies were performed.


RESULTS
Transmission electron microscopy showed sprouting, transcapillary pillars of intussusception, thickened endothelial cells with large nuclei, and increased interendothelial junctional cleft number and length. Compared to nontransgenic littermates, there was a significant increase in the lengths and numbers of the interendothelial junctional clefts, along with a decrease in the length ratios of tight junction to interendothelial junctional clefts in both the early and late disease stages. In the early and late skin lesions, scanning electron microscopy of vascular corrosion casts showed disorganization of the capillary network hierarchy with increased density of capillary sprouts. Confocal microscopy of the animals with early and late skin lesions showed significant reduction in tight junction protein claudin-5.


CONCLUSIONS
Angiogenesis is the major pathologic feature in this model of atopic dermatitis. The chronic skin inflammation is intertwined with and may cause the angiogenesis, but the angiogenesis itself is likely to be important in this disease process.
Agha-Majzoub
Rania
R
Department of Dermatology, University of Illinois, Chicago, 60612, USA.
Becker
Robert P
RP
Schraufnagel
Dean E
DE
Chan
Lawrence S
LS
D000818:Animals; D003876:Dermatitis, Atopic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D020405:Dermis / Q000098:blood supply* / Q000648:ultrastructure; D004195:Disease Models, Animal; D015847:Interleukin-4 / Q000235:genetics* / Q000378:metabolism; D053547:Keratin-14; D007633:Keratins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
D053547:Keratin-14; C507446:Krt14 protein, mouse; D015847:Interleukin-4; D007633:Keratins