Structure and hair follicle-specific expression of genes encoding the rat high sulfur protein B2 family

High sulfur proteins are cysteine-rich proteins synthesized during the differentiation of hair matrix cells, and form hair fibers in association with hair keratin intermediate filaments. Rat high sulfur protein B2 genes were isolated after screening of a rat genomic library using the cDNA as a probe. Sequence analysis of a 4 kb fragment revealed two high sulfur protein genes, B2E and B2F. Both genes lacked introns, with B2F being located at 2 kb downstream of B2E. The 5' flanking regions of both genes had TATA and CAAT boxes, and consensus sequences of B2 genes. The upstream region of B2F had possible AP-1 and Sp-1 binding elements. The high sulfur protein B2E and B2F, which have putative 188 and 122 amino acids, respectively, comprised four distinct domains with a characteristic repetitive sequence. In situ hybridization indicated that the mRNA of high sulfur protein B2 was specifically localized in the cortex of the hair shaft, and northern blot analysis indicated that the expression of B2 increased in anagen and decreased in telogen, suggesting that high sulfur protein B2 synthesized in cortical cells during anagen contributes to the production of hair fibers.

The expression of endothelin-1 and its binding sites in mouse skin increased after ultraviolet B irradiation or local injection of tumor necrosis factor alpha

Endothelin (ET)-1 is a 21-amino acid peptide which has vasoconstrictor and growth regulatory activity. Recently, cultured keratinocytes have been reported to express ET-1 and its receptor when irradiated by ultraviolet (UV) B. In order to further understand the role of ET-1 in vivo during UVB-induced inflammation, we examined the localization, intensity and time course of the expression levels of ET-1 and its binding sites in UVB-exposed BALB/c mouse skin. Frozen and paraffin sections prepared from mouse skin 48 h after treatment with UVB irradiation (0.36 or 0.72 J/cm2) or after injection with tumor necrosis factor (TNF)-alpha (1.0 microgram) or interleukin (IL)-1 alpha (0.05 microgram) were incubated with monoclonal anti-ET-1 IgG and then visualized by peroxidase staining. In normal skin, faint ET-1 immunoreactivity was observed in the epidermis, pilosebaceous structures and blood vessels. Upon exposure to UVB irradiation or administration of TNF-alpha injection or IL-1 alpha injection, such immunoreactivity was found to be significantly enhanced. Subsequently, the frozen sections were incubated with 125I ET-1 for 30 min, and visualized by autoradiographic technique. In normal skin, ET-1 weakly bound to the skin, while UVB irradiation and TNF-alpha injection significantly enhanced ET-1 binding in the epidermis, pilosebaceous structures and blood vessels. Time course experiments (1, 2, 4 and 7 days) indicated that ET-1 immunoreactivity and ET-1 binding peaked 1 or 2 days after UVB irradiation or TNF-alpha injection. These results suggest that the up-regulated expression of ET-1 and its binding sites in the epidermis and pilosebaceous structures may act as an autocrine/paracrine factor during UVB-induced inflammation.

Genes for a range of growth factors and cyclin-dependent kinase inhibitors are expressed by isolated human hair follicles

The mRNA expressions of various growth regulatory molecules in single human anagen hair follicles were analysed by reverse transcription and polymerase chain reaction. Approximately 370 hair follicles were isolated from 20 normal individuals, and 0.90 +/- 0.34 microgram (mean +/- SD) total RNA was extracted per whole hair follicle. The mRNAs of fibroblast growth factor (FGF)-1, FGF-2, FGF-5, FGF-7, transforming growth factor (TGF)-alpha, TGF-beta 1, hepatocyte growth factor, insulin-like growth factor (IGF)-I, tumour suppressor gene p53 and high sulphur protein were detected in most or all of the examined hair follicles per target gene. In contrast, none of the mRNAs of FGF-3, FGF-4, FGF-6, FGF-9 and IGF-II was detected, and those of TGF-beta 2 and TGF-beta 3 were detected in only a limited number of the examined hair follicles. Among cyclin-dependent kinase inhibitors, the mRNAs of p21waf1/cip1 and p27kip1 were expressed in almost all the hair follicles, while those of p15INK4B and p16INK4A were not detected. These results suggest that both positive and negative factors for the proliferation and differentiation of follicular epithelial cells coexist in a human anagen hair follicle.

Combination of insulin-like growth factor (IGF)-I and IGF-binding protein-1 promotes fibroblast-embedded collagen gel contraction

Wound contraction is an important event that minimizes the wound defect during the healing process. Involvement of insulin-like growth factor (IGF)-I and IGF-binding protein (IGFBP)-1 in wound contraction was studied using an in vitro model. Human dermal fibroblasts (1 x 10(5) cells/ml) were incorporated into a porcine type I collagen (0.21% final) in serum-free medium. The fibroblast-embedded collagen gels in a 12-well plate were floated from the well, and various reagents were then added to the assay medium. The surface area of the gel was calculated by measuring the diameters of the collagen gel. IGF-I at high doses (30 and 100 ng/ml) revealed 6.8% (P < 0.01) and 7.7% (P < 0.001) gel contraction, respectively, and des (1-3) IGF-I at 10 ng/ml produced a 4.5% gel contraction (P < 0.01). Meanwhile, IGFBP-I did not induce any significant contraction throughout the tested concentrations (0.1-100 ng/ml). A combination of IGF-I and IGFBP-1 at 1 ng/ml of each reagent, a concentration at which gel contraction was not observed when each of the reagents was tested individually, produced a 14% gel contraction (P < 0.001), whereas combinations of des (1-3) IGF-I with IGFBP-1 at the same concentrations did not promote gel contraction. The increased IGFBP-I doses in combination with 1 ng/ml IGF-I tended to enhance the gel contraction. IGF-I- and IGFBP-1-induced gel contraction was prominent during the initial 12-h incubation period. When anti-IGF-I, anti-IGFBP-1, or anti-IGF-I receptor antibody was added to the assay medium before the addition of IGF-I and IGFBP-1, the IGF-I- and IGFBP-1-induced gel contraction was significantly suppressed (P < 0.001). Endothelin-1, a vasoconstrictor peptide that is known to promote fibroblast-embedded collagen gel contraction, appeared to be partially involved in the IGF-I- and IGFBP-1-induced gel contraction, because the addition of an endothelin receptor antagonist (Bosentan or BE-18257B at 1 microg/ml) moderately suppressed the IGF-I- and IGFBP-1-induced gel contraction (P < 0.01). On the other hand, when IGF-I and IGFBP-1 were applied with endothelin-1 (1 nM), an enhanced gel contraction (29.4%) was observed that was significantly greater than that induced by either individually (P < 0.001). These results clearly indicate that the combination of IGF-I and IGFBP-1 promotes fibroblast contraction in collagen gel, and that this phenomenon is caused by IGFBP-1's strong potentiation of the IGF-I-induced gel contraction.

Immunolocalization of epimorphin in skin

Epimorphin was originally identified as a mesenchymal cell surface-associated protein that modulates epithelial morphogenesis in embryonic skin and lung epithelia. A previous report which utilized embryonic mouse skin, showed that epimorphin was localized non-homogeneously in a region adjacent to the epidermis and in a mesenchymal cell condensation located in front of growing hair follicles. We report herein a further detailed localization of this protein in adult mouse skin using immunoelectron microscopy. Epimorphin was found to be localized on the undersurface of basal cells, in the cytoplasm of cell processes of fibroblasts, as well as on the plasma membrane of fibroblasts, endothelial cells, pericytes, perineurium and endomysium. Our present finding indicated that epimorphin is one of the factors involved in multiple biological functions in a variety of structures derived from various origins and that it is not a specific epithelial morphogenetic factor.

Induction of an extracellular esterase from Candida albicans and some of its properties

An extracellular esterase from Candida albicans A-714 was found to be induced in a medium containing 0.7% yeast nitrogen base and 2.5% Tween 80 (polyoxyethylenesorbitan compounds). Enzyme activity, which exists predominantly in the extracellular space, was measured by a colorimetric method using alpha-naphthyl palmitate as a substrate. The induction level of the esterase activity was found to be well correlated with fungal growth and was dependent on the Tween 80 concentration. Such esterase activity was observed only in medium containing Tween 80 or other Tweens as the sole carbon source and therefore was not observed in either peptone-glucose medium or peptone-glucose medium supplemented with Tween 80. The induced esterase was heat labile and had maximum activity at pH 5.5. Enzyme activity was stimulated by the addition of sodium taurocholate, an activator of lipase. Thin-layer chromatography revealed that this enzyme does not hydrolyze triolein and L-alpha-lecithin, suggesting that it is a monoester hydrolase (not a lipase in the strict sense of the word). Esterase activity was examined in 85 clinical isolates of Candida species; C. albicans, C. tropicalis, and C. parapsilosis tended to have higher enzyme activities than C. kefyr, C. krusei, C. glabrata, and C. guilliermondii. Although the physiological properties of this esterase are not clear at present, it was found to be crucial for fungal growth under specific conditions.

Giant mixed tumor of the face

A 35-year-old Japanese man consulted our clinic with an eight year history of a 6 cm diameter subcutaneous tumor on the left cheek. Hematoxylin and eosin staining of the resected section showed histology corresponding to a benign chondroid syringoma. Keratin was positive in most of the constituent cells, and S-100 protein was positive in the cells distant from the lumens and in myxomatous cells. A benign chondroid syringoma of this size has only been very rarely reported in the literature.

Hepatocyte growth factor/scatter factor expressed in follicular papilla cells stimulates human hair growth in vitro

Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional polypeptide which acts as mitogen, motogen, or morphogen. In this study, we examined the effect of HGF/SF on human hair growth using organ and cell culture systems. HGF/SF was found to stimulate hair length and DNA synthesis in hair follicles at increasing concentrations up to 10 ng/ml (P < 0.05 and P < 0.01, respectively). HGF/SF stimulated [3H]thymidine incorporation by hair bulb-derived keratinocytes with the strongest response at 30 ng/ml of HGF/SF (P < 0.05). Cultured follicular papilla cells secreted HGF/SF, measured by an enzyme-linked immunoassay, in response to interleukin 1-alpha (IL1-alpha, 10 ng/ml), tumor necrosis factor-alpha (TNF-alpha, 10 ng/ml), or tetradecanoylphorbolacetate (100 nM) at levels ranging from 0.2 to 0.3 ng/mg protein/48 h. HGF/SF mRNA expressions, measured by the reverse transcription-polymerase chain reaction, were detected in follicular papilla cells, and were also stimulated by the three reagents. Transforming growth factor-beta (10 ng/ml) suppressed both protein and mRNA levels. These results suggest that hair follicle elongation induced by HGF/SF in organ culture occurs partly due to the mitogenic activity of HGF/SF expressed in follicular papilla cells on hair bulb-derived keratinocytes.

The effect of hepatocyte growth factor/scatter factor on human hair follicle growth

The effect of hepatocyte growth factor/scatter factor (HGF/SF) on human hair follicle growth was examined using a serum-free organ culture system. The DNA synthesis in human hair follicles and elongation of the hair shaft were measured subsequent to the follicle isolation and culture at 31 degrees C in 95% O2-5% CO2 for 72 h. Results showed that HGF/SF significantly increased 3H-thymidine (P < 0.001) incorporation and hair follicle length (P < 0.05). The effect of HGF/SF was dose-dependent with a maximal stimulation at 10 ng/ml.

Ultraviolet B irradiation increases endothelin-1 and endothelin receptor expression in cultured human keratinocytes

The effect of ultraviolet B (UVB) irradiation on endothelin-1 (ET-1) and ET receptor expression was examined using cultured normal human keratinocytes. Keratinocytes secreted ET-1 in the medium at a level of 2.1 pg/day/10(5) cells. UVB irradiation up to 10 mJ/cm2 increased ET-1 secretion 3-fold, and potentiated expression of mRNA for ET-1. Both ETA and ETB receptor mRNAs were detected in keratinocytes, and their expression was up-regulated by 5 mJ/cm2 UVB irradiation.

A carbohydrate-degrading enzyme from Candida albicans: correlation between alpha-glucosidase activity and fungal growth

Attempts to detect inducible carbohydrate-degrading enzymes from C. albicans were performed using carbohydrate-restricted media. Although alpha-amylase (polysaccharide hydrolase) was not induced from media containing starch or dextrin, alpha-glucosidase (disaccharide hydrolase) was induced from maltose-containing medium. alpha-Glucosidase activity was detected from the intact cells in suspension and from the supernatant of both spheroplasted and mechanically broken cells, but not from the media. Enzyme activity in intact cells was pH independent and increased during logarithmic growth phase and in media containing lower concentrations of maltose. The addition of 5 mM 1-deoxynojirimycin, a competitive inhibitor of alpha-glucosidase, suppressed fungal growth by more than 50%. These results suggest that alpha-glucosidase activity is crucial for fungal growth in medium containing maltose as a sole carbon source.

A case of Behçet's disease aggravated by gingival infection with methicillin-resistant Staphylococcus aureus

We report a case of Behçet's disease aggravated by gingivitis and carious teeth infected with methicillin-resistant Staphylococcus aureus. Recurrent severe ulcers in the mouth, and on the genitalia and legs were closely linked with the infection, and dramatically improved after extraction of the carious teeth and administration of systemic vancomycin hydrochloride.

Comparative study of hepatocyte growth factor/scatter factor and keratinocyte growth factor effects on human keratinocytes

Hepatocyte growth factor/scatter factor (HGF/SF) and keratinocyte growth factor (KGF, also designated FGF-7) are paracrine growth factors secreted by mesenchymal cells and active on a variety of epithelial cell types. In this study, the biologic responses of keratinocytes to these paracrine growth factors were compared. Stimulation of mitogenesis, migration, plasminogen activator (PA) activity, and fibronectin production were examined using human foreskin keratinocytes cultured in serum-free MCDB 153 medium. Although the two factors stimulated a similar level of proliferation when cells were maintained for 5 d in 1.8 mM Ca++, the peak effect of KGF, observed at 10 ng/ml, was approximately threefold higher than that of HGF/SF when cells were in medium containing 0.15 mM Ca++. Both agents promoted the migration of cells in low-calcium medium (0.08 mM Ca++). However, the magnitude of the response was approximately twofold greater for HGF/SF at 10 ng/ml than KGF at the same concentration. None of the matrix proteins such as type I collagen, type IV collagen, laminin, or fibronectin either stimulated or suppressed HGF/SF- or KGF-stimulated keratinocyte migration. Both factors stimulated PA activity of the cell extracts, especially urokinase-type, with similar potencies. Promoted PA activity was maximal with the addition of 10 ng/ml of either factor. Neither factor increased the production of fibronectin under conditions in which transforming growth factor-beta 1 was active. These results indicate that HGF/SF and KGF, both recognized as paracrine growth factors, elicit distinctive patterns of response by keratinocytes, implying that they have different roles in epidermal physiology.

Co-administration of insulin-like growth factor (IGF)-I and IGF-binding protein-1 stimulates wound healing in animal models

The stimulatory effect of recombinant human insulin-like growth factor-I (rhIGF-I) and recombinant human insulin-like growth-factor-binding protein-1 (rhIGFBP-1) on wound healing was assessed using diabetic db/db mice and normal rabbits. Full-thickness wounds of 6 mm diameter were prepared on the backs of diabetic C57BL/KsJ db/db mice and on the inner sides of normal rabbit ears. Various concentrations of rhIGF-I and/or rhIGFBP-1 were applied locally to the open wounds of db/db mice once daily for 5 d and to the covered wounds of normal rabbits once after wounding. Sections of the wounds were evaluated histologically on the seventh or eighth day by measuring re-epithelialization (%), area of granulation tissue (mm2), and capillary numbers. Wound repair was accelerated by each of the treatments in descending order of rhIGF-I plus rhIGFBP-1, rhIGF-I, rhIGFBP-1, and vehicle alone. In db/db mice, the combination of 50 micrograms rhIGF-I and 165 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated granulation tissue formation (p < 0.01) and capillary numbers (p < 0.05). Doses of rhIGFBP-1 greater than 16.5 micrograms were required for significant acceleration of the healing stimulated by 50 micrograms of rhIGF-I. In normal rabbits, co-administration of 10 micrograms rhIGF-I and 33 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated all three wound-healing parameters (p < 0.01), with such stimulation being much greater than that induced by rhIGF-I alone. Interestingly, rhIGFBP-1 alone showed a mild stimulatory activity on wound healing in both models despite its lack of mitogenic activity in vitro. These results demonstrate that rhIGFBP-1 enhances the stimulatory activity of rhIGF-I on wound healing and suggest the clinical utility of the co-administration of rhIGF-I and rhIGFBP-1 for wound repair.

A case of angiocentric T-cell lymphoma presenting as lethal midline granuloma

A case of angiocentric T-cell lymphoma with glabellar skin being the only affected site was reported. A 43-year-old woman had a several months' history of glabellar swelling followed by progressive and destructive ulceration of the region. Histopathology of the biopsied specimen showed panniculitis with atypical lymphocytes and degenerative vessels filled with atypical cells. Most of the infiltrated lymphocytes were positive for CD2, CD3, CD4 and CD5. Antibodies to Epstein-Barr virus were detected in the patient serum. Intensive chemotherapy using a protocol of the L17M regimen was partially effective for clinical manifestations. Angiocentric T-cell lymphoma presenting as lethal midline granuloma is a rare but distinct entity with an acute fatal course.

Scanning electron microscope observation of adherence of Candida albicans to cultured keratinocytes

The role of antigen 6 in the adherence process of Candida albicans serotype A to cultured keratinocytes was examined with a scanning electron microscope. The number of adhered organisms was significantly lower for the antigen 6-deficient mutant strain than for the antigen 6-positive parent strain (P < 0.001). Fibril- or strand-like structures bridging the organisms and the keratinocytes were found to develop during the later stages of adherence.