Display of the pres regions of the surface antigen of Hepatitis B virus on M13 and T7 Bactetiophages

Hepatitis B virus (HBV) is the prototype of the family Hepadnaviridae, which causes liver disease in humans, mammals and birds. The envelope of HBV contains three related surface antigens (termed L-, M- and S-HBsAg) produced by alternative initiation of translation in a single coding region. These polypeptides harbour a common 226 amino acids at their C-terminus, which is also the entire length of the S-HBsAg. The M-HBsAg contains an N-terminal extension of 55 amino acids known as the PreS2 region. The longest of the three, L-HBsAg, has the PreS 1 region of 108 or 119 amino acids (depending on serotype) followed by the PreS2 and the S regions. The PreS domain is believed to be involved in virion assembly and attachment to a hepatocyte receptor during infection. In order to study the functions of this region, the PreS and PreS 1 domains were fused to the g3p protein of bacteriophage Ml3 and lOB protein of bacteriophage T7, respectively, that allow the fusion proteins to be displayed. The PreS-g3p fusion protein produced in a suppressor strain of Escherichia coli was detected by the antiE tag antibody with a size of approximately 66 kDa on a Western blot. In a nonsuppressor strain of E. coli, the soluble PreS protein was detected in the medium, periplasm and cytoplasm with a molecular mass of approximately 22 kDa. Meanwhile in the T7 system, the first and second halves of PreS 1 were detected by the T7 Tag antibody on a Western blot with a size of around 50 kDa. The functional display of the PreS region would provide an alternative means to study its interactions with the nucleocapsid and hepatocytes. Precise definition of the regions and specific amino acids in L-HBsAg that are required for efficient interaction with the nucleocapsid and hepatocytes, may help to identify lead compounds for therapeutic agents based upon inhibition of viral morphogenesis

Characterisation of a rat model of post-herpetic neuralgia

Varicella-zoster virus (VZV) is an alphaherpesvirus that causes childhood chickenpox, becomes latent in dorsal root ganglia (DRG) after primary infection and subsequently may reactivate to cause shingles (zoster). It is essential to understand the molecular mechanisms governing VZV latency and reactivation because approximately 20% of the human population will develop zoster and possibly experience post-herpetic neuralgia (PHN), a debilitating pain syndrome associated with zoster. Little is known about the pathogenesis of PHN mainly due to a previous lack of a good animal model and the cell-associated nature of VZV in vitro. An in vivo model of latent VZV in the adult rat was adapted. Foot reflex withdrawal responses has been shown to persist for longer than 60 days post infection similar to changes seen in PHN patients. The aim of this study was to further characterise this model so that it could provide a useful and unique opportunity to study the host-virus interaction involved in the pathogenesis of PHN. Nested PCR was able to detect viral DNA in the different lumbar DRG but the low level of latent gene expression gave no direct correlation of the observed behavioural changes with the pattern of gene expression in the infected DRG. Real-time PCR was developed, a quantitative assay, to investigate the low abundance of the latent genes. Viral DNA could also be detected in microdissected cells, which provide an alternative for investigating the gene expression in each subneuronal population in the DRG. Time course study showed that viral DNA was present in the infected DRG as early as 24 h post infection and viremia was not detected from 1 to 3 days post infection. This suggested that the spread of the virus is mainly through axonal pathway. Viral DNA could not be detected in other tissues like spleen, spinal cord and brain suggested that the latent virus was limited to the peripheral nervous system. RT-PCR was able to detect viral transcripts in infected cells but not in the latently infected DRG due to the low abundance of viral genome copy and limitation in detection of the assay. Therefore, a global approach was taken to look at the transcriptional activity in the latently infected neurones by carrying out a microarray experiment. The Rat Expression Set 230A GeneChip was used in this study. Of the 15,866 known rat genes represented on the RAE 230A, 5295 probe sets were not detected (33%). 9556 genes detected on both samples, of which 332 with altered expression and 57 of them has an increase in expression. Of the 57 increased in expression, 32 met the cut-off of 50 and only 5 had a fold change of greater than 2. Due to the tissue heterogeneity, only a small fraction of cells in the DRG harbours latent VZV. A small difference in expression might give rise to a large difference on a whole ganglion basis. Of the ten genes which were significantly regulated, prostaglandin D2 synthase was validated by real time PCR and showed an upregulation of 2.7 fold corroborate with the results from microarray. PGDt was reported recently to have neuroprotective role in the nervous system. This study is in effect a pilot study giving a general overview of the changes within the DRG and thus provide a source of further characterisation of this model to understand the pathogenesis of the VZV induced allodynia

DIGITAL HEARING AID SIGNAL PROCESSING SYSTEM USING ANDROID PHONE

Objective: The objective of this research is to propose an Android-based digital hearing aid signal processing algorithm with following key features:(1) Regenerated audio match the patient-specific pattern of hearing loss, (2) noise reduction, and (3) provide flexibility to the users.Methods: The proposed signal processing algorithm is designed based on the specific hearing loss of the hearing disorder patient using inverse Fouriertransform; besides, noise reduction feature is included in the digital algorithm design as well. Proposed digital algorithm has been implemented intoan Android-based smartphone and its performance has been tested under real-time condition.Results: Simulation results show that the frequency response of the proposed digital hearing aid signal processing algorithm is in agreement withthe initial theoretical design that was carried out based on the hearing impaired patient’s audiogram. The proposed algorithm has been implementedin the Android-based smartphone and tested in real time. Results show that most of the patients are satisfied with the regenerated audio quality.According to patient’s comments, the regenerated audio is clear and the users are allowed to control the volume level. Besides, no obvious hearinglatency can be detected.Conclusion: Audio signals generated by the proposed digital signal processing algorithm show similar audio signal frequency response in boththeoretical design and MATLAB simulation results. The only difference between the design and simulation results is the amplification levels. Theproposed algorithm provides flexibility to the users by allowing them to choose the desired amplification level. In real-time testing, the proposedAndroid-based digital hearing aid is able to reduce noise level from the surrounding and the output processed speech match the patient-specifichearing loss

G9a mediates Sharp-1–dependent inhibition of skeletal muscle differentiation

10.1091/mbc.E12-04-0311Molecular Biology of the Cell23244778-478

G9a mediates Sharp-1–dependent inhibition of skeletal muscle differentiation

10.1091/mbc.E12-04-0311Molecular Biology of the Cell23244778-478

The effects of a synthetic curcuminoid analogue,2,6-bis-(4-hydroxyl-3-methoxybenzylidine)cyclohexanone on proinflammatorysignaling pathways and CLP-induced lethal sepsis in mice.

We previously showed that 2,6-bis-(4-hydroxyl-3-methoxybenzylidine)cyclohexanone (BHMC), suppressed the synthesis of various proinflammatory mediators. In this study we explain the mechanism of action of BHMC in lipopolysaccharide (LPS)-induced U937 monocytes and further show that BHMC prevents lethality of CLP-induced sepsis. BHMC showed dose-dependent inhibitory effects on p38, JNK and ERK 1/2 activity as determined by inhibition of phosphorylation of downstream transcription factors ATF-2, c-Jun and Elk-1 respectively. Inhibition of these transcription factors subsequently caused total abolishment of AP-1–DNA binding. BHMC inhibited p65 NF-κB nuclear translocation and DNA binding of p65 NF-κB only at the highest concentration used (12.5 μM) but failed to alter phosphorylation of JNK, ERK1/2 and STAT-1. Since the inhibition of p38 activity was more pronounced we evaluated the possibility that BHMC may bind to p38. Molecular docking experiments confirmed that BHMC fits well in the highly conserved hydrophobic pocket of p38 MAP kinase. We also show that BHMC was able to improve survival from lethal sepsis in a murine caecal-ligation and puncture (CLP) model

Effects of 3-(2-Hydroxyphenyl)-1-(5-methyl-furan-2-y-l) propenone (HMP) upon signalling pathways of lipopolysaccharide-induced iNOS synthesis in RAW 264.7 cells.

NO synthesis in the RAW 264.7 murine macrophage line. The inhibition of NO synthesis was related to inhibition of p38 phosphorylation and kinase activity that led to significant inhibition of phosphorylation of ATF-2. This effect in turn caused inhibition of AP-1-DNA binding which partially explains the inhibitory effect upon the synthesis of iNOS. HMP had no effect upon phosphorylation of JNK, ERK1/2 and STAT-1. Kinase activity of JNK and ERK1/2 was also not affected by HMP as determined by levels of phosphorylated c-jun and phosphorylated elk-1. Furthermore HMP failed to block phosphorylation of IκBα, and subsequent nuclear translocation and DNA-binding activity of p65 NF-κB in IFN-γ/LPS-induced RAW 264.7 cells. Molecular docking experiments confirmed that HMP fits well in the highly conserved hydrophobic pocket of p38 MAP kinase. We conclude that the synthetic HMP is a chalcone analogue that selectively inhibits the p38/ATF-2 and AP-1 signaling pathways in the NO synthesis by the macrophage RAW 264.7

Lysine methyltransferase G9a methylates the transcription factor MyoD and regulates skeletal muscle differentiation

10.1073/pnas.1111628109Proceedings of the National Academy of Sciences1093841-84

A synthetic curcuminoid derivative inhibits nitric oxide and proinflammatory cytokine synthesis

Curcumin is a highly pleiotropic molecule with significant regulatory effects upon inflammation and inflammatory related diseases. However curcumin has one major important limitation in which it has poor bioavailability. Design of synthetic structural derivatives of curcumin is but one approach that has been used to overcome its poor bioavailability while retaining, or further enhancing, its drug-like effects. We have synthesized a series of curcumin analogues and describe the effects of 2,6-bis-4-(hydroxyl-3-methoxy-benzylidine)-cyclohexanone or BHMC upon nitric oxide and cytokine synthesis in cellular models of inflammation. BHMC showed a significant dose-response inhibitory action upon the synthesis of NO and we have shown that this effect was due to suppression of both iNOS gene and enzyme expression without any effects upon scavenging of nitrite. We also demonstrated that BHMC has a very minimal effect upon iNOS activity with no effect at all upon the secretion of PGE(2) but has a strong inhibitory effect upon MCP-1 and IL-10 secretion and gene expression. Secretion and gene expression of TNF-alpha and IL-6 were moderately inhibited whereas IL-8 and IL-1beta were not altered. We conclude that BHMC selectively inhibits the synthesis of several inflammatory mediators. BHMC should be considered a promising drug lead for preclinical and further pharmacological studies

Metabolic health status and fecundability in a Singapore preconception cohort study

Background: Obesity compromises metabolic health and female fertility, yet not all obese women are similar in metabolic status. The extent to which fecundability is influenced by the metabolic health status of women who are overweight or obese before conception is unknown. Objective: This study aimed to: (1) determine the metabolic health status, and (2) examine the association between metabolic health status and fecundability of overweight and obese women trying to conceive in the Singapore PREconception Study of long-Term maternal and child Outcomes cohort study. Study Design: We conducted a prospective preconception cohort study of Asian women (Chinese, Malay, and Indian) aged 18 to 45 years trying to conceive who were treated from 2015 to 2017 in KK Women's and Children's Hospital in Singapore (n=834). We defined women to have metabolically unhealthy status if they: (1) met 3 or more modified Joint Interim Statement metabolic syndrome criteria; or (2) had homeostasis model assessment-insulin resistance index ≥2.5. Body mass index was categorized as normal (18.5–22.9 kg/m2), overweight (23–27.4 kg/m2), or obese (≥27.5 kg/m2) on the basis of cutoff points for Asian populations. Fecundability was measured by time to pregnancy in menstrual cycles within a year of enrolment. Discrete-time proportional hazards models were used to estimate fecundability odds ratios, with adjustment for confounders and accounting for left truncation and right censoring. Results: Of 232 overweight women, 28 (12.1%) and 25 (10.8%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Of 175 obese women, 54 (30.9%) and 93 (53.1%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Compared with metabolically healthy normal-weight women, lower fecundability was observed in metabolically unhealthy overweight women on the basis of metabolic syndrome criteria (fecundability odds ratios, 0.38 [95% confidence interval, 0.15–0.92]) and homeostasis model assessment-insulin resistance (fecundability odds ratios, 0.68 [95% confidence interval, 0.33–1.39]), with metabolic syndrome criteria showing a stronger association. Metabolically unhealthy obese women showed lower fecundability than the healthy normal-weight reference group by both metabolic syndrome (fecundability odds ratios, 0.35; 95% confidence interval, 0.17–0.72) and homeostasis model assessment-insulin resistance criteria (fecundability odds ratios, 0.43; 95% confidence interval, 0.26–0.71). Reduced fecundability was not observed in overweight or obese women who showed healthy metabolic profiles by either definition. Conclusion: Overweight or obesity was not synonymous with having metabolic syndrome or insulin resistance. In our preconception cohort, metabolically unhealthy overweight and obese women showed reduced fecundability, unlike their counterparts who were metabolically healthy. These findings suggest that metabolic health status, rather than simply being overweight and obese per se, plays an important role in fecundability.acceptedVersionPeer reviewe