Tight junctions in epidermis: from barrier to keratinization.

Tight junctions (TJs) are one type of intercellular junction. TJs prevent diffusion of solutes through the intercellular spaces in simple and stratified epithelia. Mice lacking claudin-1 (an adhesion molecule at TJs) show dehydration from the skin by impaired barrier function of epidermal TJs.

Characterization of tight junctions and their disruption by UVB in human epidermis and cultured keratinocytes.

It has not been confirmed whether tight junctions (TJs) function as a paracellular permeability barrier in adult human skin. To clarify this issue, we performed a TJ permeability assay using human skin obtained from abdominal plastic surgery. Occludin, a marker protein of TJs, was expressed in the granular layer, in which a subcutaneously injected paracellular tracer, Sulfo-NHS-LC-Biotin (556.

An activating beta1 integrin mutation increases the conversion of benign to malignant skin tumors.

Identifying the physiologic relevance of cancer-associated genetic polymorphisms is a major challenge. Several changes in the coding sequence of beta integrin subunits have now been described in human tumors. One of these, T188Ibeta1, was identified as a heterozygous mutation in a poorly differentiated squamous cell carcinoma (SCC) and shown to activate extracellular matrix adhesion and inhibit keratinocyte differentiation in vitro.

Tight junction proteins in keratinocytes: localization and contribution to barrier function.

Recent research suggests that tight junctions (TJs) are located in the stratum granulosum, where they contribute to the barrier function of the epidermis. In this study, we investigated the formation of functional TJs in cultured normal human epidermal keratinocytes. We observed the development of permeability barrier function through the process of Ca(2+)-induced differentiation.

Expression of CCR5 in graft-versus-host disease (GVHD) of the skin: immunohistochemical staining of 38 cases.

To ascertain the involvement of CCR5 in prolongation of graft-versus-host disease (GVHD), we performed immunohistochemical staining of CCR5 in 38 GVHD samples (23 acute and 15 chronic). A total of seven out of 15 cases of chronic GVHD were positive for CCR5; however, only two out of 23 in acute GVHD were positive for CCR5. In three cases, expression of CCR5 in infiltrating lymphocytes was negative in the acute phase, but positive in the chronic phase of GVHD.

HAN11 binds mDia1 and controls GLI1 transcriptional activity.

Background: The Hedgehog pathway is important in normal and diseased skin. One of the key transcription factors in the pathway is GLI1. GLI1-dependent transcription is positively regulated by DYRK1A, which is reported to bind HAN11.

Mouse homologue of skin-specific retroviral-like aspartic protease involved in wrinkle formation.

Retroviral proteases are encoded in the retroviral genome and are responsible for maturation and assembly of infectious virus particles. A number of retroviral protease sequences with retroviral elements are integrated in every eukaryotic genome as endogenous retroviruses. Recently, retroviral-like aspartic proteases that were not embedded within endogenous retroviral elements were identified throughout the eukaryotic and prokaryotic genomes.

Tight junctions in Schwann cells of peripheral myelinated axons: a lesson from claudin-19-deficient mice.

Tight junction (TJ)-like structures have been reported in Schwann cells, but their molecular composition and physiological function remain elusive. We found that claudin-19, a novel member of the claudin family (TJ adhesion molecules in epithelia), constituted these structures. Claudin-19-deficient mice were generated, and they exhibited behavioral abnormalities that could be attributed to peripheral nervous system deficits.

Identification of novel keratinocyte-secreted peptides dermokine-alpha/-beta and a new stratified epithelium-secreted protein gene complex on human chromosome 19q13.1.

We performed high-throughput in situ hybridization screening of sections of mouse epidermis using an equalized skin cDNA library as probes and identified a novel gene giving rise to two splicing variants, both of which are expressed in the spinous layer. This gene was mapped between two genes encoding keratinocyte-related peptides, suprabasin and keratinocyte differentiation-associated protein (Kdap), on human chromosome 19q13.1.

Expression patterns of claudins, tight junction adhesion molecules, in the inner ear.

Tight junctions (TJs) are indispensable for the establishment of compositionally distinct fluid compartments in the inner ear, but our knowledge of the claudins, TJ adhesion molecules, in the inner ear is still fragmentary. We examined the expression and distribution of claudin-1 to claudin-18 (except for claudin-7, -13 and -17) in the inner ear by immunofluorescence microscopy. In the cochlea, the organ of Corti expressed claudin-1, -2, -3, -9, -10, -12, -14 and -18.

Expression of claudin-5 in dermal vascular endothelia.

Claudins and occludin are integral membrane proteins at tight junctions (TJs). We examined subcellular localization of claudin-5 and occludin in dermal vascular endothelia. Immunofluorescence staining showed that claudin-5 was expressed at the cell-cell border of dermal vascular endothelia in mouse skin.

Tight junctions in the skin.

Tight junctions (=zonulae occludentes, TJs) function as an effective barrier in simple epithelia. Recent developments in the molecular biology of TJs revealed that TJs also exist in the stratum granulosum and contribute to barrier function in epidermis. Furthermore, several TJ-related junctions were identified in epidermis.

Seventeen cases of alopecia areata: combination of SADBE topical immunotherapy with other therapies.

Topical immunotherapy is effective for severe alopecia areata. However, there are patients with alopecia areata refractory to topical immunotherapy alone. We tried SADBE (squaric acid dibutylester) topical immunotherapy combined with topical dry ice cryotherapy, carpronium chloride (a parasympathetic nerve stimulant) and/or oral cepharanthin (a biscoclaur alkaloid) in alopecia areata refractory to topical SADBE.

Molecular architecture of tight junctions of periderm differs from that of the maculae occludentes of epidermis.

Occludin and claudins are tetraspan-transmembrane proteins in tight junctions. Maculae occludentes, which are less-developed tight junctions, occur in the granular cell layer of the epidermis. The periderm, which overlies the developing epidermis and functions as a protective layer for the embryo, carries developed tight junctions as observed in simple epithelia.