2,4,6-Triphenyl-1-hexene, an Anti-Melanogenic Compound from Marine-Derived Bacillus sp. APmarine135

Although melanin protects against ultraviolet radiation, its overproduction causes freckles and senile lentigines. Recently, various biological effects of metabolites derived from marine microorganisms have been highlighted due to their potential for biological and pharmacological applications. In this study, we discovered the anti-melanogenic effect of Bacillus sp. APmarine135 and verified the skin-whitening effect. Fractions of APmarine135 showed the melanin synthesis inhibition effect in B16 melanoma cells, and 2,4,6-triphenyl-1-hexene was identified as an active compound. The melanogenic capacity of 2,4,6-triphenyl-1-hexene (1) was investigated by assessing the intracellular melanin content in B16 cells. Treatment with 5 ppm of 2,4,6-triphenyl-1-hexene (1) for 72 h suppressed the α-melanocyte-stimulating hormone (α-MSH)-induced intracellular melanin increase to the same level as in the untreated control group. Additionally, 2,4,6-triphenyl-1-hexene (1) treatment suppressed the activity of tyrosinase, the rate-limiting enzyme for melanogenesis. Moreover, 2,4,6-triphenyl-1-hexene (1) treatment downregulated tyrosinase, Tyrp-1, and Tyrp-2 expression by inhibiting the microphthalmia-associated transcription factor (MITF). Furthermore, 2,4,6-triphenyl-1-hexene (1) treatment decreased the melanin content in the three-dimensional (3D) human-pigmented epidermis model MelanoDerm and exerted skin-whitening effects. Mechanistically, 2,4,6-triphenyl-1-hexene (1) exerted anti-melanogenic effects by suppressing tyrosinase, Tyrp-1, and Tyrp-2 expression and activities via inhibition of the MITF. Collectively, these findings suggest that 2,4,6-triphenyl-1-hexene (1) is a promising anti-melanogenic agent in the cosmetic industry.

A novel optical coherence tomography-based in vitro method of anti-aging skin analysis using 3D skin wrinkle mimics

BACKGROUND

Wrinkles represent a characteristic symptom of skin aging. In recent years, various studies have focused on their prevention and/or cure. However, clinical tests are still the only method available to directly detect and evaluate the anti-wrinkle efficacy of various substances. Moreover, no in vitro strategy for such anti-aging skin analysis has been reported. Therefore, in this study, we aimed to develop a novel technology to overcome these limitations.

MATERIALS AND METHODS

Full-thickness (FT) skin wrinkle mimics with various widths and depths were fabricated using a collagen stamping method. These were analyzed and compared using 2D and 3D Swept Source-Optical Coherence Tomography (SS-OCT) imaging technologies.

RESULTS

SS-OCT demonstrated superficial and cross-sectional images of the wrinkle mimics, and the size of the wrinkles was validated using image analysis. Retinoic acid treatment significantly decreased both the depth and width of wrinkles formed in the FT skin wrinkle mimics.

CONCLUSIONS

Using 3D tissue engineering and SS-OCT imaging technologies, we developed a novel in vitro technique that can directly detect skin wrinkles. This significantly efficient method could lead to an alternative strategy for animal experiments and preclinical anti-aging research on the skin.

Pseudoalteromone A, a Ubiquinone Derivative from Marine Pseudoalteromonas spp., Suppresses Melanogenesis

An ubiquinone derivative, pseudoalteromone A (1), has been isolated from two marine-derived Pseudoalteromonas spp., APmarine002 and ROA-050, and its anti-melanogenesis activity was investigated. The anti-melanogenic capacity of pseudoalteromone A was demonstrated by assessing the intracellular and extracellular melanin content and cellular tyrosinase activity in the B16 cell line, Melan-a mouse melanocyte cell line, and MNT-1 human malignant melanoma cell line. Treatment with pseudoalteromone A (40 μg/mL) for 72 h reduced α-melanocyte-stimulating hormone (α-MSH)-induced intracellular melanin production by up to 44.68% in B16 cells and 38.24% in MNT-1 cells. Notably, pseudoalteromone A induced a concentration-dependent reduction in cellular tyrosinase activity in B16 cell, and Western blot analyses showed that this inhibitory activity was associated with a significant decrease in protein levels of tyrosinase and tyrosinase-related protein 1 (Tyrp-1), suggesting that pseudoalteromone A exerts its anti-melanogenesis activity through effects on melanogenic genes. We further evaluated the skin-whitening effect of pseudoalteromone A in the three-dimensional (3D) pigmented-epidermis model, MelanoDerm, and visualized the 3D distribution of melanin by two-photon excited fluorescence imaging in this human skin equivalent. Collectively, our findings suggest that pseudoalteromone A inhibits tyrosinase activity and expression and that this accounts for its anti-melanogenic effects in melanocytes.

Study and Evaluation of the Potential of Lipid Nanocarriers for Transdermal Delivery of siRNA

The topical delivery of siRNA-based therapies has opened new avenues for the treatment of skin disorders. The use of siRNA as a therapeutic, however, is limited due to its rapid degradation and poor cellular uptake. Furthermore, the top layer of skin, the stratum corneum, is a major barrier to the delivery of topical agents. There is an unmet need for efficient topical formulations for delivering siRNA to the site of action. In this study, 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or lipofectamine is used to prepare a nanocarrier for delivering siRNA against glyceraldehyde 3-phosphate dehydrogenase (GAPDH); GAPDH expression is then evaluated at the cellular level. In addition, a dermal transport assay is designed and implemented to evaluate the penetration and delivery efficacy of siRNA in pig skin using lipid nanocarriers. The delivery of siRNA with the use of a lipid nanocarrier is significantly better than the delivery of siRNA without it. Thus, the findings identify lipid nanocarriers as excellent candidates for the transdermal delivery of siRNA for gene silencing in the skin and thus for applications in related preclinical models.

Tyrosinase-Targeting Gallacetophenone Inhibits Melanogenesis in Melanocytes and Human Skin-Equivalents

Demands for safe depigmentation compounds are constantly increasing in the pharmaceutical and cosmetic industry, since the numerous relevant compounds reported to date have shown undesirable side effects or low anti-melanogenic effects. In this study, we reported three novel inhibitors of tyrosinase, which is the key enzyme in melanogenesis, identified using docking-based high throughput virtual screening of an in-house natural compound library followed by mushroom tyrosinase inhibition assay. Of the three compounds, gallacetophenone showed high anti-melanogenic effect in both human epidermal melanocytes and a 3D human skin model, MelanoDerm. The inhibitory effect of gallacetophenone on tyrosinase was elucidated by computational molecular modeling at the atomic level. Binding of gallacetophenone to the active site of tyrosinase was found to be stabilized by hydrophobic interactions with His367, Ile368, and Val377; hydrogen bonding with Ser380 and a water molecule bridging the copper ions. Thus, our results strongly suggested gallacetophenone as an anti-melanogenic ingredient that inhibits tyrosinase.

Pyruvate Protects against Cellular Senescence through the Control of Mitochondrial and Lysosomal Function in Dermal Fibroblasts

Mitochondrial dysfunction can drive cellular senescence, which is accompanied by changes in metabolism and increases in senescence-associated secretory phenotypes. Although pyruvate, a key metabolite for numerous aspects of metabolism, has been used as general supplement in synthetic media, the physiological function of pyruvate underlying its protective role against cellular senescence under normal conditions has remained unknown. Here, we show that extracellular pyruvate prevents senescence in normal human dermal fibroblasts through increasing the generation of oxidized nicotinamide adenine dinucleotide (NAD⁺) during the conversion to lactate. Acetylated peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), vacuolar-type H⁺-ATPaseV0A1 (v-ATPaseV0A1), NF-κB p65 subunit (RelA), and histone H3 accumulate under pyruvate deprivation conditions, resulting in the onset of senescence in normal human dermal fibroblasts through the accumulation of abnormal mitochondria generated by lysosomal inactivation-induced mitophagy defects, and through an increase in senescence-associated secretory phenotypes. Furthermore, pyruvate showed a protective effect against aging phenotypes in skin equivalents, which consist of a dermis and epidermis that act similarly to in vivo skin tissues. Our findings reveal a connection between pyruvate and mitochondrial dysfunction in the progression of senescence that is, to our knowledge, previously unreported. These results suggest that the pyruvate deprivation-induced senescence model can be used to study the connection between metabolism and senescence under normal conditions.

Bioprinting of biomimetic skin containing melanocytes

This study reports a three-dimensional (3D) bioprinting technique that is capable of producing a full-thickness skin model containing pigmentation. Multiple layers of fibroblast (FB)-containing collagen hydrogel precursor were printed and crosslinked through neutralization using sodium bicarbonate, constituting the dermal layer. Melanocytes (MCs) and keratinocytes (KCs) were sequentially printed on top of the dermal layer to induce skin pigmentation upon subsequent air-liquid interface culture. Histological analysis was performed not only to confirm the formation of distinct skin layers, but also to identify the presence of pigmentation. The bioprinted skin structure showed the dermal and epidermal layers as well as the terminal differentiation of the KC that formed the stratum corneum. Moreover, the MC-containing epidermal layer showed freckle-like pigmentations at the dermal-epidermal junction, without the use of external ultraviolet light or chemical stimuli. The presented method offers the capability of producing engineered ephelides in biomimetic skin, thus rendering 3D bioprinting techniques as productive on-demand options for the creation of skin models available for therapeutic or research use.

Quantitative monitoring of laser-treated engineered skin using optical coherence tomography

Nowadays, laser therapy is a common method for treating various dermatological troubles such as acne and wrinkles because of its efficient and immediate skin enhancement. Although laser treatment has become a routine procedure in medical and cosmetic fields, the prevention of side-effects, such as hyperpigmentation, redness and burning, still remains a critical issue that needs to be addressed. In order to reduce the side-effects while attaining efficient therapeutic outcomes, it is essential to understand the light-skin interaction through evaluation of physiological changes before and after laser therapy. In this study, we introduce a quantitative tissue monitoring method based on optical coherence tomography (OCT) for the evaluation of tissue regeneration after laser irradiation. To create a skin injury model, we applied a fractional CO2 laser on a customized engineered skin model, which is analogous to human skin in terms of its basic biological function and morphology. The irradiated region in the skin was then imaged by a high-speed OCT system, and its morphologic changes were analyzed by automatic segmentation software. Volumetric OCT images in the laser treated area clearly visualized the wound healing progress at different time points and provided comprehensive information which cannot be acquired through conventional monitoring methods. The results showed that the laser wound in engineered skins was mostly recovered from within 1~2 days with a fast recovery time in the vertical direction. However, the entire recovery period varied widely depending on laser doses and skin type. Our results also indicated that OCT-guided laser therapy would be a very promising protocol for optimizing laser treatment for skin therapy.

Transcriptional profiling in human HaCaT keratinocytes in response to kaempferol and identification of potential transcription factors for regulating differential gene expression

Kaempferol is the major flavonol in green tea and exhibits many biomedically useful properties such as antioxidative, cytoprotective and anti-apoptotic activities. To elucidate its effects on the skin, we investigated the transcriptional profiles of kaempferol-treated HaCaT cells using cDNA microarray analysis and identified 147 transcripts that exhibited significant changes in expression. Of these, 18 were up-regulated and 129 were down-regulated. These transcripts were then classified into 12 categories according to their functional roles: cell adhesion/cytoskeleton, cell cycle, redox homeostasis, immune/defense responses, metabolism, protein biosynthesis/modification, intracellular transport, RNA processing, DNA modification/ replication, regulation of transcription, signal transduction and transport. We then analyzed the promoter sequences of differentially-regulated genes and identified over-represented regulatory sites and candidate transcription factors (TFs) for gene regulation by kaempferol. These included c-REL, SAP-1, Ahr-ARNT, Nrf-2, Elk-1, SPI-B, NF-kappaB and p65. In addition, we validated the microarray results and promoter analyses using conventional methods such as real-time PCR and ELISA-based transcription factor assay. Our microarray analysis has provided useful information for determining the genetic regulatory network affected by kaempferol, and this approach will be useful for elucidating gene-phytochemical interactions.

Anti-nucleosome antibody: significance in lupus patients lacking anti-double-stranded DNA antibody

OBJECTIVE

To investigate the clinical significance of anti-nucleosome antibodies in SLE patients lacking anti-double stranded DNA (dsDNA) antibodies.

METHODS

IgG anti-nucleosome antibodies were detected by enzyme-linked immunosorbent assays (ELISA) in the sera of SLE patients. Anti-dsDNA antibodies were measured by Farr assays and ELISA, not only in the samples taken for anti-nucleosome testing, but also in sera obtained regularly during the follow-up.

RESULTS

Ninety-eight (76.0%) out of 129 patients with SLE had anti-nucleosome antibodies. Twenty-five patients (19.4%) consistently showed little or no anti-dsDNA reactivity during the course of their disease, and among these anti-nucleosome antibodies were present in the sera of 15 (60.0%). Of the patients with anti-dsDNA-negative SLE, renal disorders were present in 8 patients (32.0%), all of whom had anti-nucleosome antibodies. Renal disorders were not found in patients (n = 10) who had neither anti-dsDNA nor anti-nucleosome antibodies. Other autoantibodies such as anti-Ro, anti-Sm and anti-cardiolipin were not associated with renal disorders in this group. The levels of anti-nucleosome antibody strongly correlated with the SLEDAI scores, but inversely correlated with serum complement levels in anti-dsDNA negative SLE patients.

CONCLUSION

Our data suggest that the anti-nucleosome antibody may be a useful marker for diagnosis and activity assessment of anti-dsDNA negative SLE. Anti-nucleosome antibody may be an important factor for renal involvement in this subgroup of patients.

The kinetics of circulating cytokines including IL-6, TNF-alpha, IL-8 and IL-10 following allogeneic hematopoietic stem cell transplantation

Pro-inflammatory (IL-6, TNFalpha and IL-8) and anti-inflammatory (IL-10) cytokines were determined in weekly samples from 52 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). IL-6 increased immediately after transplant peaking at week +3, but IL-8 concentrations were elevated only during week +1. After a slight decrease in week +1, TNF-alpha significantly increased from week +2 and peaked at week +3, whereas, IL-10 values started to rise in week +2 and peaked during week +4. IL-6 and TNF-alpha were positively correlated from week +2 to week +4, and IL-6 levels at week +1 were related with fever and severe stomatitis. Serum levels of IL-6 at week +1 and IL-10 at week +4 were significantly higher in patients with early transplant-related complications, such as fever, severe stomatitis or acute GVHD > or = overall grade II than in those without the complications. We conclude that a high serum IL-6 level at week +1 may be an early predictor of transplant-related complications and that it seems to trigger pro- and anti-inflammatory cytokine release. Kinetic patterns of IL-6 and IL-10 were more exaggerated in those with complications after HSCT.

Vascular endothelial growth factor levels in the serum and synovial fluid of patients with rheumatoid arthritis

OBJECTIVE

To determine the vascular endothelial growth factor (VEGF) concentrations in serum and synovial fluid (SF) from patients with rheumatoid arthritis (RA) and to search for relationships between VEGF levels and clinical and laboratory variables.

METHODS

We measured VEGF levels using an enzyme-linked immunosorbent assay. Serum samples were obtained from 99 RA patients, 49 osteoarthritis (OA) patients, and 80 normal controls. Paired samples of serum and SF were collected from 32 patients with RA and 15 with OA.

RESULTS

The mean serum VEGF concentration was 590.1 pg/ml for RA patients, 286.7 pg/ml for OA patients, and 265.8 pg/ml in controls. The serum VEGF concentration was significantly higher in the RA patients than in the OA patients or the controls (both p < 0.001). Furthermore, the VEGF levels in SF from RA patients were significantly higher than in SF from OA patients (p = 0.017). However, there was no correlation between VEGF levels in serum and SF from the same RA patients. The serum VEGF concentration was correlated with the ESR, serum CRP concentration, serum rheumatoid factor, number of tender and swollen joints, Modified Health Assessment Questionnaire, and patient and physician global assessments of disease activity in RA patients.

CONCLUSION

These results suggest that VEGF level is related to RA disease activity, suggesting that VEGF may play some role in the pathogenesis of RA.

Decreased production of interleukin-12 and interferon-gamma is associated with renal involvement in systemic lupus erythematosus

OBJECTIVE

To analyze the type 1/type 2 cytokine balance in patients with systemic lupus erythematosus (SLE) according to the presence of renal disorder and activity status.

METHODS

We measured the serum levels of type 1 (IFN-gamma, IL-12) and type 2 cytokines (IL-4, IL-10) as well as spontaneous and stimulated cytokine production from peripheral blood mononuclear cells (PBMC) in 40 patients with SLE.

RESULTS

Patients with lupus nephritis (LN) showed significantly lower levels of serum IL-12 and IFN-gamma than those without LN. Production of IL-12 and IFN-gamma by stimulated PBMC were also decreased in patients with LN. The circulating IL-12 correlated positively with IFN-gamma, but inversely with IL-10. The SLEDAI scores correlated well with the ratio of IL-4/IFN-gamma levels.

CONCLUSION

The reduced production of IL-12 and IFN-gamma and the resultant shift towards the type 2 cytokine phenotype may be associated with LN.

Shift toward T helper 1 cytokines by type II collagen-reactive T cells in patients with rheumatoid arthritis

OBJECTIVE

To investigate the impact of type II collagen (CII)-reactive T cells on the Th1/Th2 cytokine balance in patients with rheumatoid arthritis (RA).

METHODS

T cell proliferative responses to bovine CII were examined in synovial fluid mononuclear cells (SFMC) and peripheral blood mononuclear cells (PBMC) by mixed lymphocyte culture. CII-reactive T cell lines were generated from the SFMC and PBMC. Interferon-gamma (IFNgamma), interleukin-12 (IL-12), and IL-4 were measured by enzyme-linked immunosorbent assay in the SF, sera, and culture supernatants of PBMC and SFMC that had been stimulated with CII.

RESULTS

The frequency of CII-reactive T cells was higher in the PBMC from RA patients than in that from osteoarthritis patients and healthy control subjects. In RA patients, CII-reactive T cells were more prevalent in SFMC than in PBMC. The mean level of IFNgamma and the ratio of IFNgamma to IL-4 were significantly higher in the culture supernatants of T cells stimulated with CII; these differences were more prominent in SFMC. Levels of IL-12 in the culture supernatants of SFMC and PBMC stimulated with CII were significantly higher than those in unstimulated supernatants. T cell responsiveness correlated well with the level of type 1 cytokines in culture supernatants from RA T cells stimulated with CII. In the CII-reactive cell lines, the increased production of IFNgamma was consistent with clonal expansion.

CONCLUSION

CII-reactive T cells are more abundant in SFMC than in PBMC and are strongly associated with a shift toward Thl cytokine in the inflamed joints of RA patients. Our results suggest that a skewing toward type 1 cytokines by CII-reactive T cells may play an important role in the chronic inflammatory process of RA.

CD40 engagement on synovial fibroblast up-regulates production of vascular endothelial growth factor

We tested the impact of CD40 engagement on the production of vascular endothelial growth factor (VEGF) from rheumatoid synovial fibroblasts. Fibroblast-like synovial cells (FLS) were prepared from the synovial tissues of rheumatoid arthritis patients and cultured in the presence of CD40 ligand-transfected (CD40L+) L cells. VEGF levels were determined in the culture supernatants by ELISA. Stimulation of FLS by CD40L+ L cells increased the production of VEGF by 4.1-fold over the constitutive levels of unstimulated FLS. The CD40L on activated T cells from rheumatoid synovial fluid also up-regulated VEGF production from FLS. Neither indomethacin nor Abs to IL-1beta, TNF-alpha, and TGF-beta did affect CD40L-induced VEGF production. Stimulation of FLS with TNF-alpha, IL-1beta, and TGF-beta increased VEGF production by 1.6-, 2.0-, and 5.2-fold, respectively, and displayed an additive effect on the production of VEGF by CD40L. VEGF mRNA expression was also up-regulated by the stimulation of FLS with membranes from the CD40L+ L cells. Dexamethasone completely abrogated CD40L-induced VEGF production. In addition, pyrrolidine dithiocarbamate partially down-regulated CD40L-induced VEGF production, showing that the NF-kappaB pathway was partly involved in the signaling of CD40L leading to VEGF production. Collectively, these results suggest that the interaction between CD40 on synovial fibroblasts and CD40L expressed on activated T lymphocytes may be directly involved in the neovascularization in rheumatoid synovitis by enhancing the production of VEGF.

The role of IL-12 in inflammatory activity of patients with rheumatoid arthritis (RA)

The aim of this study was to investigate the role of IL-12 in patients with RA. IL-12 (p70) and its associated cytokines were measured in sera and synovial fluid (SF) using an enzyme-linked immunosorbent method. Seven American College of Rheumatology (ACR) core set measures as well as IL-12 levels were sequentially monitored at the commencement and 4 months after treatment with a low-dose steroid and disease-modifying anti-rheumatic drugs (DMARDs). In sera, 64 (42.2%) of 152 RA patients had detectable concentrations of IL-12 (p70), whereas one (1.4%) of 69 osteoarthritis (OA) patients and five (10%) of 50 healthy controls had detectable IL-12 (P < 0.001). The median level of circulating IL-12 was also higher in RA patients (P < 0.001). In SF, the number of patients with detectable IL-12 and the median IL-12 levels were significantly higher in RA patients (n = 53) than in OA patients (n = 22). In paired samples (n = 53) of sera and SF from RA patients, IL-12 levels were higher in the SF than in sera (P < 0.001). Patients with detectable IL-12 (n = 51) in sera had higher tender joint scores (P = 0.003), swollen joint scores (P < 0.001) and C-reactive protein (CRP; P = 0.036), than those without (n = 55). Four months after treatment with DMARDs, the improved group showed a larger IL-12 decrease than the non-improved group (P = 0.017). The levels of IL-12 correlated positively with those of IL-2, interferon-gamma, IL-6, and tumour necrosis factor-alpha, but were correlated inversely with those of IL-10. Our results demonstrate that IL-12 levels reflect RA disease activity and that IL-12 is involved in the production of proinflammatory cytokines. An IL-12 blockade could be useful for the treatment of RA.

Specific immobilization of in vivo biotinylated bacterial luciferase and FMN:NAD(P)H oxidoreductase

Bacterial bioluminescence, catalyzed by FMN:NAD(P)H oxidoreductase and luciferase, has been used as an analytical tool for quantitating the substrates of NAD(P)H-dependent enzymes. The development of inexpensive and sensitive biosensors based on bacterial bioluminescence would benefit from a method to immobilize the oxidoreductase and luciferase with high specific activity. Toward this end, oxidoreductase and luciferase were fused with a segment of biotin carboxy carrier protein and produced in Escherichia coli. The in vivo biotinylated luciferase and oxidoreductase were immobilized on avidin-conjugated agarose beads with little loss of activity. Coimmobilized enzymes had eight times higher bioluminescence activity than the free enzymes at low enzyme concentration and high NADH concentration. In addition, the immobilized enzymes were more stable than the free enzymes. This immobilization method is also useful to control enzyme orientation, which could increase the efficiency of sequentially operating enzymes like the oxidoreductase-luciferase system.

Behavior of Model Proteins, Pretreated in Urea and/or Dithiothreitol, at Air/Solution Interfaces

The behavior of the model proteins, lysozyme, myoglobin, and beta-casein, pretreated in urea and/or dithiothreitol, at air/solution interfaces was studied by surface pressure-area techniques. The data suggested that in the absence of pretreatments the globular proteins are only partially unfolded at the interfaces. The interfacial activity was enhanced by the pretreatment (lysozyme in 8 M urea with 0.2 M dithiothreitol and myoglobin in 8 M urea). The interfacial activity of casein, a random-coil type protein, was not influenced by the pretreatment (8 M urea), as it readily and completely unfolds at the interfaces. The unfolding of globular proteins at the interfaces is apparently restricted by both disulfide and noncovalent bonds. Pretreatment can relax those restrictions, resulting in more complete interfacial unfolding. Copyright 1998 Academic Press. Copyright 1998Academic Press