Gene expression profiles in psoriasis: analysis of impact of body site location and clinical severity.

Background: Psoriasis is characterized by symmetry of plaques and modulation of multiple genes within those plaques.

Objectives: We compared gene expression profiles of plaques of psoriasis at different anatomical sites for both symmetrical and asymmetrical disease to ascertain whether the same genes were expressed.

Methods: Gene expression profiles were analysed in biopsies from lesional and uninvolved skin from two groups of patients with either predominantly symmetrical or truncal plaques of psoriasis vulgaris, and from normal skin of healthy volunteers.

Ultraviolet B induces hyperproliferation and modification of epidermal differentiation in normal human skin grafted on to nude mice.

Background: For ethical and technical reasons, the in vivo biological effects of ultraviolet (UV) radiation on skin are difficult to study in human volunteers. The use of human skin grafted on to nude mice may circumvent this difficulty.

Objectives: To investigate the effects of a single moderate UVB exposure on human skin grafted on to nude mice.

The lanceolate hair rat phenotype results from a missense mutation in a calcium coordinating site of the desmoglein 4 gene.

Desmosomal cadherins are essential cell adhesion molecules present throughout the epidermis and other organs, whose major function is to provide mechanical integrity and stability to epithelial cells in a wide variety of tissues. We recently identified a novel desmoglein family member, Desmoglein 4 (Dsg4), using a positional cloning approach in two families with localized autosomal recessive hypotrichosis (LAH) and in the lanceolate hair (lah) mouse. In this study, we report cloning and identification of the rat Dsg4 gene, in which we discovered a missense mutation in a naturally occurring lanceolate hair (lah) rat mutant.

Genes that are differentially expressed in rat vibrissa follicle germinative epithelium in vivo show altered expression patterns after extended organ culture.

Hair growth depends on maintenance of signalling between the dermal papilla and the germinative epithelium (GE), from which the differentiated layers of the hair fibre originate. Because no molecular studies have been reported which concentrate specifically on GE cells either in vivo or in vitro, we prepared a cDNA library enriched for messages which were highly expressed in GE cells to identify genes that may be involved in hair growth control. Of 35 subtracted library clones sequenced, 23 shared extensive homology with previously determined cDNA sequences, including LEF-1 and id4.

Localisation of members of the notch system and the differentiation of vibrissa hair follicles: receptors, ligands, and fringe modulators.

Hair vibrissa follicle morphogenesis involves several cell segregation phases, in the dermis as well as in the epidermis. The expression of Notch-related genes, which are well established mediators of multiple cell segregation events in Drosophila development, was studied by in situ hybridisation during embryonic mouse vibrissa follicle morphogenesis and the first adult hair cycle. The results show that two receptors, Notch1 and -2, three ligands, Delta1, Serrate1, and -2, and the three Fringe regulators, Lunatic, Manic, and Radical, are expressed in different locations and morphogenetic stages.