Trehangelins ameliorate inflammation-induced skin senescence by suppressing the epidermal YAP-CCN1 axis.

Trehangelins (THG) are newly identified trehalose compounds derived from broth cultures of an endophytic actinomycete, Polymorphospora rubra. THG are known to suppress Cellular Communication Network factor 1 (CCN1), which regulates collagen homeostasis in the dermis. Although the physical properties of THG suggest a high penetration of the stratum corneum, the effect of THG on the epidermis has not been reported. Here we describe a possible mechanism involved in skin aging focusing on the effect of THG on epidermal CCN1. This study shows that: (1) THG suppress epidermal CCN1 expression by inhibiting the translocation of Yes-Associated Protein (YAP) to nuclei. (2) Epidermal CCN1, localized at the basement membrane, regulates the balance between the growth and differentiation of keratinocytes. (3) Keratinocytes secrete more CCN1 than fibroblasts, which leads to disruption of the basement membrane and extracellular matrix components. (4) The secretion of CCN1 from keratinocytes is increased by ultraviolet B exposure, especially in aged keratinocytes, and deteriorates the elastic fiber structures in the underlying dermis. (5) Topical application of THG ameliorates the structure of the basement membrane in ex vivo human skin explants. Taken together, THG might be a promising treatment for aged skin by suppressing the aberrant YAP-CCN1 axis.

Aldsulfin, a novel unusual anti-mannheimiosis epithiodiketopiperazine antibiotic produced by Lasiodiplodia pseudotheobromae FKI-4499.

An anti-mannheimiosis agent, aldsulfin, was isolated from a culture broth of the fungus Lasiodiplodia pseudotheobromae FKI-4499, together with a known compound, lasiodipline C, using bioassay-guided fractionation. Spectroscopic analysis of aldsulfin, using NMR, mass spectrometry, and CD analyses revealed it to be an epithiodiketopiperazine with an unstable and unusual hemithioaminal moiety. Aldsulfin showed antibacterial activity against Mannheimia haemolytica and Pasteurella multocida.

An Application of Photoactivatable Substrate for the Evaluation of Epithelial-mesenchymal Transition Inhibitors.

Epithelial-mesenchymal transition (EMT), phenotypic changes in cell adhesion and migration, is involved in cancer invasion and metastasis, hence becoming a target for anti-cancer drugs. In this study, we report a method for the evaluation of EMT inhibitors by using a photoactivatable gold substrate, which changes from non-cell-adhesive to cell-adhesive in response to light. The method is based on the geometrical confinement of cell clusters and the subsequent migration induction by controlled photoirradiation of the substrate. As a proof-of-concept experiment, a known EMT inhibitor was successfully evaluated in terms of the changes in cluster area or leader cell appearance, in response to biochemically and mechanically induced EMT. Furthermore, an application of the present method for microbial secondary metabolites identified nanaomycin H as an EMT inhibitor, potentially killing EMTed cells in disseminated conditions. These results demonstrate the potential of the present method for screening new EMT inhibitors.

Decatamariic acid, a new mitochondrial respiration inhibitor discovered by pesticidal screening using drug-sensitive Saccharomyces cerevisiae.

A new decalin, decatamariic acid, was isolated from a cultured broth of the fungus Aspergillus tamarii FKI-6817. Its absolute configuration was elucidated by NMR and electronic circular dichroism. Decatamariic acid (10 µM) elicited ~50% inhibition of the ATP production in mitochondria isolated from wild-type Saccharomyces cerevisiae without affecting the activities of respiratory enzymes. The action manner of this compound may be interesting as a possible seed for new pesticides.

Cytoprotective effects of grape seed extract on human gingival fibroblasts in relation to its antioxidant potential.

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (•OH), singlet oxygen (1O2), and hydrogen peroxide (H2O2). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H2O2, acid-electrolyzed water (AEW), and 1O2, and attenuated the intracellular formation of reactive oxygen species induced by H2O2 and AEW. Tx also reduced the H2O2- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H2O2, AEW, or 1O2. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.

Production of reactive oxygen species (ROS) by devil stinger (Inimicus japonicus) during embryogenesis.

In aqua-cultural industry, the seed production of devil stinger, a valuable fish in Japan, has not succeeded yet due to the cryptogenic mass mortality. We found that survival rate of the larvae of devil stinger increased by the addition of green tea extract rich in catechin into rearing tank. Generation of reactive oxygen species (ROS) was detected in the embryo of devil stinger by chemiluminescence analysis under the normal growth conditions without addition of specific stimulants. Even in the unfertilized egg, certain level of ROS was detected. ROS were continuously detected during the development from fertilized egg to larva and tended to increase gradually. Observation of embryos and post-hatching larvae with hypersensitive photon-counting microscopy indicated that ROS were produced on the surface of embryo and the head region of larva especially peripheries of eyes. When the embryo proteins were analyzed by immunoblotting using antibody against the human neutrophil cytochrome b558 large subunit (gp91 phox), a main band of approximately 91 kDa was detected, suggesting the presence of NADPH oxidase-like ROS generating system in the embryo of devil stinger. After treatment with streptomycin and penicillin G for 1 day, the level of ROS production in larvae decreased with increase in the survival rate of larvae. Our results suggest that devil stinger has ROS generation system that is already activated at fairly early stage of development before the maturation of usual immune system.

Evaluation of the anti-Trichophyton activity of a prodigiosin analogue produced by gamma-proteobacterium, using stratum corneum epidermis of the Yucatan micropig.

Prodigiosins (PGs) are known to be a family of natural red pigments, characterized by a common pyrrolydipyrrolylmethane skeleton structure with a C-4 methoxy group, and some of these pigments have been isolated from some microorganisms. Members of the PG family have been reported to show several biological activities, such as immunosuppressive and cytotoxic activities. Recently, we discovered a bacterial strain (MS-02-063), from our microbial library, that produces large amounts of a PG analogue (PG-L-1). In this study, we examined the anti-Trichophyton activity of PG-L-1 (produced by strain MS-02-063) against clinically isolated Trichophyton spp., by a method using stratum corneum epidermis (SCE) of the Yucatan micropig, which is suitable for estimating the antifungal activity of drugs in vitro. In the National Committee for Clinical Laboratory Standards (NCCLS) method, PG-L-1 showed potent antifungal activity against nine clinically isolated strains of Trichophyton spp., although the minimum inhibitory concentration (MIC) values were slightly higher than those of bifonazole. In spite of the lower efficiency of PG-L-1 transfer into SCE from medium than that of bifonazole, PG-L-1 transferred into SCE showed more potent antifungal activity than bifonazole, at lower concentrations.

Development of a new medium useful for the recovery of dermatophytes from clinical specimens by minimizing the carryover effect of antifungal agents.

Two surface-active compounds, egg lecithin and polysorbate 80, usually used as the deactivators of various preservatives were tested whether they also counteract either or all of the three major topical antifungal drugs, bifonazole (BFZ), lanoconazole (LCZ) and terbinafine (TBF). Both egg lecithin and polysorbate 80, when added to culture media up to final concentrations of 1.0 and 0.7%, respectively, antagonized the anti-dermatophytic activity of the three drugs in a concentration-dependent manner. A greater extent of antagonistic action was exerted when the two deactivators combined at their maximal levels tested were added; MIC's of BFZ were increased more than 30-fold and those of LCZ and TBF more than 200-fold compared with the values obtained in the absence of the deactivators. Using the agar medium supplemented with the combined deactivators, culture studies were carried out with skin tissues specimens taken from guinea pigs whose feet were infected with dermatophytes and subsequently treated with 1% topical preparations of the three antifungal drugs. The experimental data from this animal study demonstrated that the combined deactivators-supplemented medium yielded increased numbers of fungi compared with the basal medium. It looks, therefore, likely that the fungal recovery on the former medium more correctly reflects to actual fungal burden in the infected lesions than the latter. All these results suggest that the combined deactivators-supplemented medium is more useful for mycological evaluation of therapeutic efficacy of imidazole and allylamine drugs against dermatophytoses in both preclinical and clinical studies.