Cultivation of human dermal microvascular endothelial cells in vitro: Immunocytochemical and ultrastructural characterization and effect of treatment with three synthetic retinoids

Abstract

A new reliable and reproducible technique to culture endothelial cells from the small vessels and capillaries of human skin is introduced, and proliferation and differentiation of the growing cells are characterized. The endothelial origin of the culture cells was confirmed by light- and electron microscopy and by labelling with Ulex europaeus Agglutinin I and an antibody against Factor VIII-related antigen. Further immunocytochemical characterization showed that 92-100% of the cells were positive for beta 2-microglobulin and the entire cell population expressed vimentin, whereas cytokeratins, desmin, HLA-DR antigen, Leu 6 and S 100 protein, could not be detected. As vascular endothelium is a common site of inflammation and retinoids have been shown to be of good clinical efficacy in some chronic inflammatory skin diseases, we investigated the influence of etretinate, etretin and isotretinoin on proliferation and antigen expression of our culture cells. All retinoids applied inhibited proliferation of endothelial cells in a dose- and time-dependent manner whereas they induced neither HLA-DR nor intercellular adhesion molecule-1 (ICAM-1). Furthermore, none of the retinoids applied influenced the gamma-interferon-induced expression of these surface antigens on endothelial cells. Our results suggest that the action of retinoids in skin inflammation is not mediated by modulation of HLA-DR or ICAM-1. The cell culture technique described here is an interesting and reliable model for studying the influence of drugs on endothelial cell growth and differentiation in vitro.

Intercellular adhesion molecule-1 and CD36 synergize to mediate adherence of Plasmodium falciparum-infected erythrocytes to cultured human microvascular endothelial cells.

“…Thus, we conclude that synergy is a property of parasites expressing particular var genes and the degree of synergy seen is a function of the proportion of those clones in the whole parasite population. This finding is in keeping with our previous observations of the relationship between antigenic and phenotypic variation and the importance of subpopulations in determining the overall population phenotype (35,42). Our data are important for two reasons.…”

“…HDMEC were obtained from human foreskin tissue using an adaptation to previously published methods (33)(34)(35). Human foreskin tissue was obtained with local ethical committee approval from elective circumcisions performed at the John Radcliffe Hospital and stored in M199 medium containing 400 U/ml penicillin, 200 mg/ml streptomycin at 4 Њ C for up to 24 h before use.…”

Retinoic acid inhibits the regulated expression of vascular cell adhesion molecule-1 by cultured dermal microvascular endothelial cells.

“…In transformed cell lines, retinoids have been shown to induce ICAM-1 expression or augment its upregulation by other known inducers of ICAM-1 (26,27). However, in primary cell cultures such as epidermal keratinocytes or EC, retinoids have not been found to induce ICAM-1 in significant amounts (28,29). Consistent with our observations, studies on the cytokine-induced ICAM-1 expression in dermal microvascular EC did not reveal inhibitory effects with the retinoid compound acitretin (30).…”

British Association of Dermatologists guidelines on the efficacy and use of acitretin in dermatology

“…4,5 It is thought to exert these effects by interfering with the expression of epidermal growth factor genes. There is also evidence that acitretin has immunomodulatory properties by inhibiting dermal microvascular endothelial cells 6 and neutrophil migration. 7,8 Acitretin is licensed for use in severe extensive psoriasis which is resistant to other forms of therapy, including topical, light and systemic; palmoplantar pustular psoriasis; severe Darier disease (keratosis follicularis) and severe congenital ichthyosis.…”