Study of in vitro capillary-like structures in psoriatic skin substitutes

Angiogenesis is one of the important hallmarks of psoriasis. The extension of the superficial microvascular structure and activated pro-angiogenic mediators in psoriasis seem to be important factors involved in the pathology. According to the changes of superficial microvasculature in psoriatic lesions, anti-angiogenic treatment could be a promising therapeutic strategy for psoriasis. The aim of this study was to construct an in vitro vascularized psoriatic skin substitute for fundamental research. Psoriatic fibroblasts and keratinocytes were isolated from psoriatic plaque biopsies, while healthy fibroblasts and keratinocytes, as well as microvascular endothelial cells, were isolated from healthy skin biopsies of cosmetic breast surgery. Psoriatic and healthy skin substitutes with and without endothelial cells were produced using the self-assembly approach. Afterward the substitutes were examined by histology, immunofluorescence studies, and three-dimensional (3D) confocal microscopy. Histological analysis and immunofluorescence staining of specific markers for endothelial cells (von Willebrand, PECAM-1 [CD31], and VE-cadherin [CD144]) and basement membrane component (collagen IV) demonstrated that endothelial cells have the ability to form capillary-like tubes. Moreover, the 3D branched structure of the capillary-like structures and an eagle eye view of them were observed by confocal microscopy. Also the semiquantification of capillary-like tubes (CLTs) was carried out with a 3D eagle eye view of substitutes, and more CLTs were observed in psoriatic substitutes. These results suggest that it is possible to observe 3D capillary-like structures in the self-assembled psoriatic skin substitutes, which could become a good in vitro testing model for anti-angiogenic drug research, and facilitate the study of this complex pathology, which links angiogenesis to its development.