Anti-ultraviolet, antibacterial, and biofilm eradication activities against Cutibacterium acnes of melanins and melanin derivatives from Daedaleopsis tricolor and Fomes fomentarius.

Fomes fomentarius and Daedaleopsis tricolor produced significant amounts of water-insoluble melanins, and our previous study successfully enhanced their water solubility by arginine modification. This research aimed to investigate the anti-ultraviolet, antibacterial, and biofilm eradication activities of both the melanins and arginine-modified melanin (melanin derivatives) from these two fungi against an acne-causing bacterium (Cutibacterium acnes). Apart from these, the cytotoxicity of the melanins and melanin derivatives on human skin cells was also evaluated. Melanin derivatives of both two fungi showed significantly higher antibacterial and biofilm eradication activities compared with their original forms. Specifically, the MIC50 values of the melanin derivatives (1,000 µg/mL) are the same as those of erythromycin. Regarding biofilm eradication capacity, the MBEC50 value of D. tricolor melanin derivative (250 µg/mL) was just half of both erythromycin and F. fomentarius melanin derivative. However, it required a 2-fold higher concentration of melanin derivatives than erythromycin to inhibit 90% of the bacterial population and eradicate 90% of their biofilm. Regarding anti-ultraviolet activity, blending melanins or melanin derivatives with a moisturizer/sunscreen enhanced their UV light absorption and the sun protection factor (SPF) values. In addition, melanins showed better effects than their derivatives, and those of D. tricolor were better than F. fomentarius. Remarkably, adding D. tricolor melanin (10%) to a Nivea pure cream could turn this cream into a broad-spectrum sunscreen, with its SPF value and critical wavelength increasing from 7.74 and 338.67 to 14.02 and 377.0, respectively. In addition, adding melanin or a melanin derivative of D. tricolor to an Olay sunscreen enhanced the SPF and the critical wavelength of the sunscreen from 17.25 and 371.67 to 23.82 and 374 and 23.38 and 372, respectively. Notably, melanins and melanin derivatives showed no toxicity in human fibroblasts. The obtained data suggest that arginine modification significantly enhanced the antibacterial and biofilm eradication activities of melanins from D. tricolor and F. fomentarius. However, this is not the case when it comes to their anti-ultraviolet activities. In addition, melanin and melanin derivatives from D. tricolor are potential candidates for anti-acne sunscreen products and are worth further investigation.

Increases in both HIV and syphilis among men who have sex with men in Vietnam: Urgent need for comprehensive responses.

The objective of this study was to determine the temporal trends and factors associated with HIV and syphilis infection among men who have sex with men (MSM) in southern Vietnam. Data from the 2014-2018 national HIV sentinel surveillance of MSM aged 16 years or older were collected from three provinces, including An Giang (N = 761), Can Tho (N = 900), and Ho Chi Minh City (N = 1426), and examined for changes in prevalence rates of HIV and syphilis and risk behaviors over time. Multivariate logistic regression was performed to assess the trends and correlates of HIV and syphilis infections among MSM. There were upward trends for HIV (9.5% in 2014 to 14.2% in 2018, p-trend<0.01), syphilis (4.9% in 2014 to 8.0% 2018, p-trend<0.01), and HIV/syphilis co-infection (1.9% in 2014 to 3.1% in 2018, p-trend=0.01). Factors associated with HIV infection included place of residence, early sexual debut, consistent condom use and not engaging in anal sex during the past month, not knowing one's HIV test results, having ever injected drugs, and having active syphilis. Additionally, early sexual debut and being HIV positive were associated with syphilis infection. Rising prevalences of these infections among MSM suggests an urgent need for comprehensive intervention packages for HIV/STI prevention.

Epigenetic regulation of intragenic transposable elements impacts gene transcription in Arabidopsis thaliana.

Genomes of higher eukaryotes, including plants, contain numerous transposable elements (TEs), that are often silenced by epigenetic mechanisms, such as histone modifications and DNA methylation. Although TE silencing adversely affects expression of nearby genes, recent studies reveal the presence of intragenic TEs marked by repressive heterochromatic epigenetic marks within transcribed genes. However, even for the well-studied plant model Arabidopsis thaliana, the abundance of intragenic TEs, how they are epigenetically regulated, and their potential impacts on host gene expression, remain unexplored. In this study, we comprehensively analyzed genome-wide distribution and epigenetic regulation of intragenic TEs in A. thaliana. Our analysis revealed that about 3% of TEs are located within gene bodies, dominantly at intronic regions. Most of them are shorter and less methylated than intergenic TEs, but they are still targeted by RNA-directed DNA methylation-dependent and independent pathways. Surprisingly, the heterochromatic epigenetic marks at TEs are maintained within actively transcribed genes. Moreover, the heterochromatic state of intronic TEs is critical for proper transcription of associated genes. Our study provides the first insight into how intragenic TEs affect the transcriptional landscape of the A. thaliana genome, and suggests the importance of epigenetic mechanisms for regulation of TEs within transcriptional gene units.