Peptide YY inhibits transcription and replication of hepatitis B virus by suppressing promoter/enhancer activity.

Hepatitis B virus (HBV) infection is a noteworthy cause of liver diseases, especially cirrhosis and hepatocellular carcinomas. However, the interaction between the host and HBV has not been fully elucidated. Peptide YY (PYY) is a 36-amino-acid gastrointestinal hormone that is mainly involved in the regulation of the human digestive system. This study found that PYY expression was reduced in HBV-expressing hepatocytes and HBV patients. Overexpression of PYY could significantly inhibit HBV RNA, DNA levels, and the secretion of HBsAg. In addition, PYY inhibits HBV RNA dependent on transcription through reducing the activities of CP/Enh I/II, SP1 and SP2. Meanwhile, PYY blocks HBV replication independent on core, polymerase protein and ε structure of pregenomic RNA. These results suggest that PYY can impair HBV replication by suppressing viral promoters/enhancers in hepatocytes. Our data shed light on a novel role for PYY as anti-HBV restriction factor.

Interferon-alpha responsible EPN3 regulates hepatitis B virus replication.

Hepatitis B virus (HBV) infection remains a major health problem worldwide, and the current antiviral therapy, including nucleoside analogs, cannot achieve life-long cure, and clarification of antiviral host immunity is necessary for eradication. Here, we found that a clathrin-binding membrane protein epsin3 (EPN3) negatively regulates the expression of HBV RNA. EPN3 expression was induced by transfection of an HBV replicon plasmid, and reduced HBV-RNA level in hepatic cell lines and murine livers hydrodynamically injected with the HBV replicon plasmid. Viral RNA reduction by EPN3 was dependent on transcription, and independent from epsilon structure of viral RNA. Viral RNA reduction by overexpression of p53 or IFN-α treatment, was attenuated by knockdown of EPN3, suggesting its role downstream of IFN-α and p53. Taken together, this study demonstrates the anti-HBV role of EPN3. The mechanism how it decreases HBV transcription is discussed.

Influence of order-to-disorder transitions on the optical properties of the aluminum plasmonic metasurface.

To mimic the optical influence of disorder in condensed matter, the effect of uniform disorder on plasmonic resonances were investigated numerically and experimentally on aluminum (Al) nanoparticle arrays. Resorting to the analogue of a plasmonic periodic array to a crystal on the sharp optical spectrum and its anisotropy, the disorder in the transition from crystal to glass (with broadened spectrum and isotropy) is imitated by three kinds of Al plasmonic metasurfaces: varying the displacement, size and rotation of each Al nanoparticle in the periodic array. The random variation on the location or size of each Al nanodisk in the plasmonic crystal induces broadening and reduction of their plasmonic resonances without significantly shifting its wavelength. Moreover, by rotating each Al nanorod in the plasmonic crystal by a random angle, the polarization dependence of plasmonic resonances is progressively decreased by increasing the rotation disorder. Thanks to these three kinds of Al metasurfaces, an enlightened understanding of the random physics in the solid state and the influence of manufacturing deviation in nanophotonics is supported.

Prediction of multiple resonance characteristics by an extended resistor-inductor-capacitor circuit model for plasmonic metamaterials absorbers in infrared.

The resonance characteristics of plasmonic metamaterials absorbers (PMAs) are strongly dependent on geometric parameters. A resistor-inductor-capacitor (RLC) circuit model has been extended to predict the resonance wavelengths and the bandwidths of multiple magnetic polaritons modes in PMAs. For a typical metallic-dielectric-metallic structure absorber working in the infrared region, the developed model describes the correlation between the resonance characteristics and the dimensional sizes. In particular, the RLC model is suitable for not only the fundamental resonance mode, but also for the second- and third-order resonance modes. The prediction of the resonance characteristics agrees fairly well with those calculated by the finite-difference time-domain simulation and the experimental results. The developed RLC model enables the facilitation of designing multi-band PMAs for infrared radiation detectors and thermal emitters.