Overexpression Of Vascular Endothelial Growth Factor Receptors In Psoriasis

Psoriasis is a common, chronic skin disease characterizedby recurrent erythematous skin plaques that exhibit epidermalhyperplasia, abnormalities of the papillary dermal vasculatureand a variable inflammatory cell infiltration. We always thought that the epidermis was the most important role in the processof pathology. But considerable evidence indicates that micovascular changed observed in psoriasis appeared firstly,influence on the pathogenesis of psoriasis and followed withe epidermal hyperplasia, and a variable inflammatory cell infiltration. Neovascularization is the critical step leading the start of the pathogenesis of psoriasis. Migration of a lot of active immunity cells and cytokins out of the blood vessel which be caused by proliferation of the blood and raise of permeabglit accelerate the neovascularization on the contrary. This is apositive feedback.A critical step in the sequence of events leading toneovasculatization involves interaction and delicious balanceof cytokine. The result of Michal and our previous study show that VEGF autosecreted by keratinocyteiplay the most important role in the change of papillary dermal microvessels Mediated by two specific receptors expressed on the blood endothelialcell (fms-like tyrosine kinase /FLT-1, VEGFR-1 and kinase insertdomain-containing receptor /KDR, VEGFR-2). The role promotingproliferation of two specific receptors belonging to the familyof tyrosinase have been proved by many results of study in pathophysiology of tumor and embryo. Considering the similarity between the above and inflammatory disease, we believe that the two receptors play a critic role during the process of pathophysiology of psoriasis. Our purpose of the presentinvestigation was tO demonstrate expression kDR and FLT-1 protein and mRNA by immunohistochemistry and in situ hybridization and the microvessel density stained by CD34. We use normal skin as control group to discuss the relationship among expression off \FLT-1, KDR and abnormal angiogenesis in psoriasis and to determine whether and what extent KDR and FLT-1 have a role in the pathophysiologic programming of psoriasis. In this report, we further proved that KDR and FLT-1 was expressed on microvasculature of dermis reported by Michal Detmar, further demonstrated that the positive correlative relationship havestatistic significance among FLT-1, KDR and microvascular density (MVD).ObjectiveTo study the expression of vascular endothelial growth factor receptors (FLT-1 and KDR) in the lesion skin of psoriasis and which extent FLT-1 and KDR have a role in the pathophysiologic programming of psoriasis.Materials and methodsWe determined the expression of FLT-1/KDR protein and mRNA with streptavidin-peroxidase immunohistochemistry and in situ hybridization in 28 cases of paraffin-embedded punch biopsiesof the psoriatic lesion. At same time, 19 cases (normal controlswere obtained from individuals. The semiquantitative study ofmorphologic change was microscopically performed. The relationships between the FLT-1/KDR expression, vascular hyperpermeability, angiogenesis and the morphologic changes were also studied.Results1 In the epidermis, FLT-1/KDR proteins were expressed principally by cell of the granular layer. In contrast, FLT-1/KDR proteins expression presented throughout the whole normal epidermis. There was no significant difference between the total level of receptors in epidermis of psoriasis and that of the normal controls.72 In the epidermis of psoriatic lesion, the maximum expression FLT-1/KDR mRNA were detected in the basal layers. In the normal skin, they were detected throughout all layers.3 The expression of FLT-1/KDR proteins on the papillary dermal microvessels in psoriatic lesion is statistically significantly higher than that in the control group.4 Higher levels of FLT-1/KDR mRNA were found on the papillary dermal microvessels of the psoriatic lesion than that of the normal skin.5 The expression of FLT-1/...