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Barrier Homeostasis (barrier + homeostasi)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

The stratum corneum: structure and function in health and disease

DERMATOLOGIC THERAPY, Issue 2004
Clive R. Harding
ABSTRACT:, Our understanding of the formation, structure, composition, and maturation of the stratum corneum (SC) has progressed enormously over the past 30 years. Today, there is a growing realization that this structure, while faithfully providing a truly magnificent barrier to water loss, is a unique, intricate biosensor that responds to environmental challenges and surface trauma by initiating a series of biologic processes which rapidly seek to repair the damage and restore barrier homeostasis. The detailed ultrastructural, biochemical, and molecular dissection of the classic "bricks and mortar" model of the SC has provided insights into the basis of dry, scaly skin disorders that range from the cosmetic problems of winter xerosis to severe conditions such as psoriasis. With this knowledge comes the promise of increasingly functional topical therapies. [source]

Effects of metals on skin permeability barrier recovery

EXPERIMENTAL DERMATOLOGY, Issue 8 2010
Mitsuhiro Denda
Please cite this paper as: Effects of metals on skin permeability barrier recovery. Experimental Dermatology 2010; 19: e124,e127. Abstract:, We previously demonstrated that the electrical state of the skin surface influences epidermal permeability barrier homeostasis. At the interface between different materials, electrons are localized heterogeneously and induce electrical potential. In the present study, we evaluated the effects of metals on the barrier recovery. When we put pure gold plate on skin immediately after tape stripping, the barrier recovery rate was faster than the control. The acceleration of barrier recovery was blocked when the plate was earthed (grounded). When a plastic membrane was sandwiched between the plate and the skin, the recovery was delayed in comparison with the control. We then used a germanium diode to regulate the current flow between the plate and the earth. When the current was blocked, the barrier recovery was accelerated, but when the current was not blocked, the recovery was not accelerated. These results suggest that localization of electron might affect for the barrier recovery rate. The level of interfacial electric potential would be different due to the electrochemical property of metal. Thus, we next evaluated the effects of other metals. With samarium, zirconium, iridium and silver, the barrier recovery rate was faster than in the case of gold, while a platinum plate induced slower recovery than in the case of gold. There was a significant correlation between work function of each metal and barrier recovery rate. These results suggest that electron donation from outside accelerated the skin barrier recovery. [source]

Sodium lauryl sulphate alters the mRNA expression of lipid-metabolizing enzymes and PPAR signalling in normal human skin in vivo

EXPERIMENTAL DERMATOLOGY, Issue 12 2009
Hans Törmä
Abstract:, Detergents irritate skin and affect skin barrier homeostasis. In this study, healthy skin was exposed to 1% sodium lauryl sulphate (SLS) in water for 24 h. Biopsies were taken 6 h to 8 days post exposure. Lipid patterns were stained in situ and real-time polymerase chain reaction (PCR) was used to examine mRNA expression of enzymes synthesizing barrier lipids, peroxisome proliferator-activated receptors (PPAR) and lipoxygenases. The lipid pattern was disorganized from 6 h to 3 days after SLS exposure. Concomitant changes in mRNA expression included: (i) reduction, followed by induction, of ceramide-generating ,-glucocerebrosidase, (ii) increase on day 1 of two other enzymes for ceramide biosynthesis and (iii) persistent reduction of acetyl-CoA carboxylase-B, a key enzyme in fatty acid synthesis. Surprisingly, the rate-limiting enzyme in cholesterol synthesis, HMG-CoA reductase, was unaltered. Among putative regulators of barrier lipids synthesis, PPAR, and PPAR, exhibited reduced mRNA expression, while PPAR,/, and LXR, were unaltered. Epidermal lipoxygenase-3, which may generate PPAR, agonists, exhibited reduced expression. In conclusion, SLS induces reorganization of lipids in the stratum corneum, which play a role in detergents' destruction of the barrier. The changes in mRNA expression of enzymes involved in synthesizing barrier lipids are probably important for the restoration of the barrier. [source]

Androgen action on human skin , from basic research to clinical significance

EXPERIMENTAL DERMATOLOGY, Issue 2004
Christos C. Zouboulis
Abstract:, Androgens affect several functions of the human skin, such as sebaceous gland growth and differentiation, hair growth, epidermal barrier homeostasis and wound healing. Their effects are mediated by binding to nuclear androgen receptors. Androgen activation and deactivation are mainly intracellular events. They differ from cell type to cell type and between cells at different locations. The major circulating androgens, dehydroepiandrosterone sulfate and androstenedione, are predominantly produced in the adrenal glands, and testosterone and 5,-dihydrotestosterone are mainly synthesized in the gonads. Testosterone in women and 5,-dihydrotestosterone in both genders are also synthesized in the skin. Skin cells express all androgen metabolizing enzymes required for the independent cutaneous synthesis of androgens and the development of hyperandrogenism-associated conditions and diseases, such as seborrhea, acne, hirsutism and androgenetic alopecia. The major thrust of drug design for the treatment of androgen-associated disorders has been directed against several levels of androgen function and metabolism. Partial effectiveness has only been achieved either by androgen depletion, inhibition of androgen metabolism or blockade of the androgen receptor. [source]