In this chapter, we describe an organ culture method that allows skin tissues isolated from 12.5- or 13.5-d postcoitus mouse embryos to develop in a manner histologically and temporally similar to the process in vivo. In this culture system, epidermal growth factor specifically and complete ...
In this chapter, we present technical details for the generation of in vitro skin equivalents consisting of collagen gels with incorporated fibroblasts covered by proliferating and differentiating keratinocytes. Epithelial-mesenchymal interactions are clearly manif ...
In vitro fabrication of human epidermal tissues that mimic the biochemical and morphologic properties of human skin, known as skin-equivalent (organotypic) cultures, has opened new avenues in the study of skin biology. In this chapter, methods for the generation of these tissues from their ...
Recent work from our laboratory has led to the development and validation of fluorescence-activated cell sorting (FACS)-based techniques to prospectively isolate viable keratinocyte stem cells from both human and murine skin. Here we describe a step-by-step method to apply our techn ...
It is well accepted that homeostasis of continuously renewing adult tissues, such as the epidermis, is maintained by somatic stem cells. These are undifferentiated, self-renewing cells, which also produce daughter transit amplifying (TA) cells that make up the majority of the prolifer ...
The skin is a dynamic tissue in which terminally differentiated keratinocytes are replaced by the proliferation of new epithelial cells that will undergo differentiation. The rapid and continual turnover of skin throughout life depends on a cell population with unique characteris ...
To identify slowly cycling (label-retaining) keratinocytes in the cutaneous epithelium of mice, newborn female pups were injected with -thymidine twice daily for 3 d beginning the third day after birth. At 8–10 wk of age, skin from the dorsal side of the mice was removed and fixed. The skin was process ...
Primary adult mouse keratinocytes are harvested from the dorsal section of 6- to 8-wk-old mice. Euthanized mice are clipped and sterilized with serial washes in provodine iodine and ethanol solutions. The skin of the mice is removed and treated with trypsin to detach the dermis from the epidermis. ...
Reverse transcription polymerase chain reaction is used for the semiquantitative analysis of epidermal gene expression, particularly when immunolocalization is not feasible because of the lack of antibodies available for novel genes. This chapter is therefore devoted to the de ...
Immunohistochemistry is an efficient means of localizing specific proteins to their relative expression compartment in the epidermis thereby providing evidence as to their functionality. This chapter therefore describes a dependable method for immunolocalization wit ...
The zebrafish (Danio rerio) is a member of the teleost (bony fish) lineage that diverged from the mammalian lineage 420 million years ago. Despite this ancient divergence, there are important similarities between the epidermis of fish and mammals. In addition, recent work suggests that the ge ...
HOX homeodomain proteins are thought to be master developmental regulators of tissue patterning during embryogenesis. These DNA binding proteins also have diverse roles in adult cell function, and derangement of HOX genes has been associated with several types of cancer. In this chapt ...
The multigene E2F family of transcription factors is central in the control of cell cycle progression. The expression and activity of E2F proteins is tightly regulated transcriptionally and posttranslationally as a function of the proliferation and differentiation status of the c ...
Keratinization is a specialized form of apoptosis that produces the stratum corneum concomitant with keratinocyte cell death. Apoptosis of keratinocytes occurs not only during normal keratinization but also in response to various intracellular or extracellular death stimu ...
Single-cell suspensions of primary keratinocytes comprise a heterogeneous cell population that consists of basal cells (stem cells, transient amplifying cells, and post-mitotic basal cells) and suprabasal cells at different stages of differentiation. Quantitative data for ...
In epidermal cells desmosomes represent major sites of basolateral cell-cell contacts that play an important role for epidermal homeostasis. Excess or damaged cells are often removed by apoptosis. To release apoptotic cells from the tissue, intercellular contacts have to be broken. H ...
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are known to play important roles in the metabolism of epidermal tissue. Among them, MMP-9 and its relatively specific inhibitor, TIMP-1, have been reported to be involved in a variety of pathophysio ...
S100 proteins are the largest subgroup of Ca2+ binding proteins with the EF-hand structural motif. A unique feature of this protein family is that individual members are localized in specific cellular compartments. For example, various S100 proteins are expressed in very restricted reg ...
Cell kinetic studies provide important information on histogenesis in vivo and in vitro. In this regard, specific antibodies to cell cycle-related antigens have been raised and characterized, thus permitting the study of cell kinetics using immunochemical methods. Recent advanc ...
In this chapter, postembedding immunoelectron microscopy methods for studies of cornified cell envelopes are provided. Human epidermal tissue samples are used as the material. The samples are cryofixed without chemical fixation, freeze-substituted at a low temperature, and emb ...