Three‐Dimensional Tissue Models of Normal and Diseased Skin

Abstract

Over the last decade, the development of in vitro, human, three‐dimensional (3D) tissue models, known as human skin equivalents (HSEs), has furthered understanding of epidermal cell biology and provided novel experimental systems. Signaling pathways that mediate the linkage between growth and differentiation function optimally when cells are spatially organized to display the architectural features seen in vivo, but are uncoupled and lost in two‐dimensional culture systems. HSEs consist of a stratified squamous epithelium grown at an air‐liquid interface on a collagen matrix populated with dermal fibroblasts. These 3D tissues demonstrate in vivo–like epithelial differentiation and morphology, and rates of cell division, similar to those found in human skin. This unit describes fabrication of HSEs, allowing the generation of human tissues that mimic the morphology, differentiation, and growth of human skin, as well as disease processes of cancer and wound re‐epithelialization, providing powerful new tools for the study of diseases in humans. Curr. Protoc. Cell Biol. 41:19.9.1‐19.9.17. © 2008 by John Wiley & Sons, Inc.

Opposing Growth Regulatory Roles of Protein Kinase D Isoforms in Human Keratinocytes

“…To study the effects of PKD silencing in the context of human epidermal tissue, control or PKD isoform knockdown NHKC were used to regenerate epidermal tissue in organotypic cultures. In this system, KCs are seeded onto a dermal equivalent and raised to the air/liquid interface to produce correctly polarized epidermis with spatially organized expression of marker proteins for proliferation and differentiation (24). As shown in Fig.…”

Three-Dimensional Human Tissue Models That Incorporate Diabetic Foot Ulcer-Derived Fibroblasts Mimic In Vivo Features of Chronic Wounds

“…1 Many existing therapies are based on research conducted in twodimensional (2D) monolayer cultures, which do not simulate the complexity of human skin and are not predictive of in vivo tissues responses. 2,3 Three-dimensional (3D), tissueengineered models more closely approximate the in vivo environment for studying skin and related tissues. 2 Use of 3D tissue models to investigate the behavior of cells derived from chronic wounds could provide meaningful correlations between both in vitro and in vivo wound responses and better direct treatment strategies.…”

In vitro skin three-dimensional models and their applications

“…Collagen I, the leading class of ECM protein, is the typically used hydrogel material, and dermal fibroblast cells are usually distributed within the collagen gel to mimic the dermal layer [34,35]. The first hydrogel system using epidermal cells on top of a primary rat fibroblast-seeded collagen scaffold was described by Bell and colleagues [36].…”

“…Its high level of differentiation makes this system a good approach to study effects on specific epidermal layers. Typically applied cell types are primary human dermal fibroblasts and primary keratinocytes [34,40], but also keratinocyte cell lines like HaCaT cells are used [38]. Simple psoriasis models, which are also commercially available (MatTek Corp., Ashland, MA, USA), are composed of healthy keratinocytes and diseased fibroblasts isolated from psoriatic lesions of patients.…”