PRMT1 and PRMT4 Regulate Oxidative Stress-Induced Retinal Pigment Epithelial Cell Damage in SIRT1-Dependent and SIRT1-Independent Manners

Oxidative stress-induced retinal pigment epithelial (RPE) cell damage is involved in the progression of diabetic retinopathy. Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs) has emerged as an important histone modification involved in diverse diseases. Sirtuin (SIRT1) is a protein deacetylase implicated in the onset of metabolic diseases. Therefore, we examined the roles of type I PRMTs and their relationship with SIRT1 in human RPE cells under H2O2-induced oxidative stress. H2O2 treatment increased PRMT1 and PRMT4 expression but decreased SIRT1 expression. Similar to H2O2 treatment, PRMT1 or PRMT4 overexpression increased RPE cell damage. Moreover, the H2O2-induced RPE cell damage was attenuated by PRMT1 or PRMT4 knockdown and SIRT1 overexpression. In this study, we revealed that SIRT1 expression was regulated by PRMT1 but not by PRMT4. Finally, we found that PRMT1 and PRMT4 expression is increased in the RPE layer of streptozotocin-treated rats. Taken together, we demonstrated that oxidative stress induces apoptosis both via PRMT1 in a SIRT1-dependent manner and via PRMT4 in a SIRT1-independent manner. The inhibition of the expression of type I PRMTs, especially PRMT1 and PRMT4, and increased SIRT1 could be therapeutic approaches for diabetic retinopathy

Emerging Need for Vaccination against Hepatitis A Virus in Patients with Chronic Liver Disease in Korea

Vaccination against hepatitis A virus (HAV) is recommended for patients with chronic liver disease (CLD), but this has been deemed unnecessary in Korea since the immunity against HAV was almost universal in adults. However, this practice has never been reevaluated with respect to the changing incidence of adult acute hepatitis A. We retrospectively reviewed the medical records of 278 patients with acute hepatitis A diagnosed from January 1995 to November 2005 and prospectively tested 419 consecutive CLD patients from July to December 2005 for the presence of IgG anti-HAV. The number of patients with acute hepatitis A has markedly increased recently, and the proportion of adult patients older than 30 yr has been growing from 15.2% during 1995-1999, to 28.4% during 2000-2005 (p=0.019). Among 419 CLD patients, the seroprevalences of IgG anti-HAV were 23.1% for those between 26 and 30 yr, 64% between 31 and 35 yr, and 85.0% between 36 and 40 yr. These data demonstrate that immunity against HAV is no more universal in adult and substantial proportion of adult CLD patients are now at risk of HAV infection in Korea. Therefore, further study on seeking proper strategy of active immunization against HAV is warranted in these populations

Black Cohosh and St. John's Wort (GYNO-Plus®) for Climacteric Symptoms

PURPOSE: This study was conducted to investigate the efficacy of black cohosh (Cimicifuga racemosa) and St. John's wort (Hypericum perforatum) in women with climacteric symptoms, and to assess their effects on vaginal atrophy, hormone levels, and lipid profiles. MATERIALS AND METHODS: In this double-blind randomized, placebo-controlled, multicenter study, 89 peri- or postmenopausal women experiencing climacteric symptoms were treated with St. John's wort and black cohosh extract (Gynoplus), Jin-Yang Pharm., Seoul, Korea) or a matched placebo for 12 weeks. Climacteric complaints were evaluated by the Kupperman Index (KI) initially and at 4 and 12 weeks following treatment. Vaginal maturation indices, serum estradiol, FSH, LH, total cholesterol, HDL- cholesterol, LDL-cholesterol, and triglyceride levels were measured before and after treatment. From the initial 89 participants, 77 completed the trial (42 in the Gynoplus group, 35 in the placebo group). RESULTS: Baseline characteristics were not significantly different between the two groups. Mean KI scores and hot flushes after 4 and 12 weeks were significantly lower in the Gynoplus group. Differences in superficial cell proportion were not statistically significant. HDL levels decreased in the control group from 60.20 +/- 16.37 to 56.63 +/- 12.67, and increased in the Gynoplus group from 58.32 +/- 11.64 to 59.74 +/- 10.54; this was statistically significant (p=0.04). CONCLUSION: Black cohosh and St. John's wort combination was found to be effective in alleviating climacteric symptoms and might provide benefits to lipid metabolismope

Mechanoluminescence Color Conversion by Spontaneous Fluorescent-Dye-Diffusion in Elastomeric Zinc Sulfide Composite

Color conversion, long-wavelength light emission by absorbing short-wavelength light, is an attractive approach for developing a broad-color expression technology and is widely used in solid-state lighting, dye-lasers, and colorful displays. Up to now, many papers have been published reporting various mechanoluminescent materials emitting color of ultraviolet, blue, green, orange, and red. However, the strategies of previous reports have focused on color-tuning of mechanoluminescent material itself through newly developing inorganic mechanoluminescent compounds. Here, a new strategy for the color manipulation of mechanoluminescence (ML) is introduced by physically combining fluorescent dyes with existing mechanoluminescent materials. An elastomeric zinc sulfide (ZnS) composite is prepared in a polydimethylsiloxane framework with spontaneously diffused 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), and red luminescence by complete color conversion via DCJTB is demonstrated, which fully absorbed green ML from ZnS. Based on this approach, color-tuning of ML from red to green is successfully achieved and color expression range is expanded by employing electroluminescence (EL). Various-color-emitting EL/ML electromechanical display is demonstrated using color discrepancy between DCJTB employed EL and ML. As the implementation is fairly straightforward, it is believed that present color conversion is a viable and common method to manipulate broader color expression for future ML applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Molecular Orientation Control of Liquid Crystal Organic Semiconductor for High-Performance Organic Field-Effect Transistors

The control of molecular orientation and ordering of liquid crystal (LC) organic semiconductor (OSC) for high-performance and thermally stable organic thin-film transistors is investigated. A liquid crystalline molecule, 2-(4-dodecyl thiophenyl) [1]dibenzothiopheno[6,5-b:6',5'-f]-thieno[3,2-b]thiophene (C12-Th-DBTTT) is synthesized, showing the highly ordered smectic X (SmX) phase, demonstrating molecular reorganization via thermal annealing. The resulting thermally evaporated polycrystalline film and solution-sheared thin film show high charge carrier mobilities of 9.08 and 27.34 cm(2) V-1 s(-1), respectively. Atomic force microscopy and grazing-incidence X-ray diffraction analyses prove that the random SmA(1)-like structure (smectic monolayer) is reorganized to the highly ordered SmA(2)-like structure (smectic bilayer) of C12-Ph-DBTTT at the crystal-SmX transition temperature region. Because of the strong intermolecular interactions between rigid DBTTT cores, the thin film devices of C12-Th-DBTTT show excellent thermal stability up to 300 degrees C, indicating that LC characterization of conventional OSC materials can obtain high electrical performance as well as superior thermal durability