Superoxide Photoproduction from Wetland Plant-Derived Dissolved Organic Matter: Implications for Biogeochemical Impacts of Plant Invasion.

Although the impacts of exotic wetland plant invasions on native biodiversity, landscape features, and carbon-nitrogen cycles are well appreciated, biogeochemical consequences posed by ecological competition, such as the heterogeneity of dissolved organic matter (DOM) from plant detritus and its impact on the formation of reactive oxygen species, are poorly understood. Thus, this study delves into O2•- photogeneration potential of DOM derived from three different parts (stem, leaf, and panicle) of invasive Spartina alterniflora (SA) and native Phragmites australis (PA). It is found that DOM from the leaves of SA and the panicles of PA has a superior ability to produce O2•-. With more stable aromatic structures and a higher proportion of sulfur-containing organic compounds, SA-derived DOM generally yields more O2•- than that derived from PA. UVA exposure enhances the leaching of diverse DOM molecules from plant detritus. Based on the reported monitoring data and our findings, the invasion of SA is estimated to approximately double the concentration of O2•- in the surrounding water bodies. This study can help to predict the underlying biogeochemical impacts from the perspective of aquatic photochemistry in future scenarios of plant invasion, seawater intrusion, wetland degradation, and elevated solar UV radiation.

Author Correction: EZH2 inhibition sensitizes BRG1 and EGFR mutant lung tumours to TopoII inhibitors.

We wish to correct two mutations in Supplementary Table 4 of this Letter. The NCI-H460 cell line was annotated as being mutant for TP53. NCI-H460 has been verified to be TP53 wild type by several sources1. The NCI-H2009 cell line was annotated as being mutant for PIK3CA. As annotated by COSMIC (ref. 24 of the original Letter) and CCLE (ref. 25 of the original Letter), the NCI-H2009 cell line has a mutation in PIK3C3, rather than PIK3CA. The cell line is wild type for PIK3CA. The Supplementary Information of this Amendment contains the corrected Supplementary Table 4. These errors do not affect our conclusions. The original Letter has not been corrected.

Overcoming EGFR(T790M) and EGFR(C797S) resistance with mutant-selective allosteric inhibitors.

The epidermal growth factor receptor (EGFR)-directed tyrosine kinase inhibitors (TKIs) gefitinib, erlotinib and afatinib are approved treatments for non-small cell lung cancers harbouring activating mutations in the EGFR kinase, but resistance arises rapidly, most frequently owing to the secondary T790M mutation within the ATP site of the receptor. Recently developed mutant-selective irreversible inhibitors are highly active against the T790M mutant, but their efficacy can be compromised by acquired mutation of C797, the cysteine residue with which they form a key covalent bond. All current EGFR TKIs target the ATP-site of the kinase, highlighting the need for therapeutic agents with alternative mechanisms of action. Here we describe the rational discovery of EAI045, an allosteric inhibitor that targets selected drug-resistant EGFR mutants but spares the wild-type receptor. The crystal structure shows that the compound binds an allosteric site created by the displacement of the regulatory C-helix in an inactive conformation of the kinase. The compound inhibits L858R/T790M-mutant EGFR with low-nanomolar potency in biochemical assays. However, as a single agent it is not effective in blocking EGFR-driven proliferation in cells owing to differential potency on the two subunits of the dimeric receptor, which interact in an asymmetric manner in the active state. We observe marked synergy of EAI045 with cetuximab, an antibody therapeutic that blocks EGFR dimerization, rendering the kinase uniformly susceptible to the allosteric agent. EAI045 in combination with cetuximab is effective in mouse models of lung cancer driven by EGFR(L858R/T790M) and by EGFR(L858R/T790M/C797S), a mutant that is resistant to all currently available EGFR TKIs. More generally, our findings illustrate the utility of purposefully targeting allosteric sites to obtain mutant-selective inhibitors.

PKD deletion promotes autophagy and inhibits hypertrophy in cardiomyocyte.

Protein kinase D (PKD) plays an important role in the development of cardiac hypertrophy induced by pressure overload. However, the mechanism involved is unclear. This study, using primary cardiomyocyte culture, PKD knockdown and overexpression, and other molecular techniques, tested our hypothesis that PKD pathway mediates cardiac hypertrophy by negatively regulating autophagy in cardiomyocyte. Neonatal cardiomyocytes were isolated from Wistar rats and cell hypertrophy was induced by norepinephrine treatment (PE, 10-4 mol/L), and divided into the following groups: (1) Vehicle; (2) PE; (3) PE + control siRNA; (4) PE + Rapamycin (100 nM); (5) PE + PKD-siRNA (2 × 108 U/0.1 ml); (6) PE + PKD siRNA + 3 MA (10 mM). The results showed that PE treatment induced cardiomyocyte hypertrophy, which were confirmed by cell size and biomarkers of cardiomyocyte hypertrophy including increased ANP and BNP mRNA. PKD knockdown or Rapamycin significantly inhibited PE-induced cardiomyocyte hypertrophy. In addition, PKD siRNA increased autophagy activity determined by electron microscopy, increased biomarkers of autophagy by Western blot, accompanied by down-regulated AKT/mTOR/S6K pathway. All the effects of PKD knockout were inhibited by co-treatment with 3-MA, an autophagy inhibitor. Oppositely, the autophagy in cardiomyocytes was inhibited by PKD overexpression. These results suggest that PKD participates in the development of cardiac hypertrophy by regulating autophagy via AKT/mTOR/S6K pathway.

EZH2 inhibition sensitizes BRG1 and EGFR mutant lung tumours to TopoII inhibitors.

Non-small-cell lung cancer is the leading cause of cancer-related death worldwide. Chemotherapies such as the topoisomerase II (TopoII) inhibitor etoposide effectively reduce disease in a minority of patients with this cancer; therefore, alternative drug targets, including epigenetic enzymes, are under consideration for therapeutic intervention. A promising potential epigenetic target is the methyltransferase EZH2, which in the context of the polycomb repressive complex 2 (PRC2) is well known to tri-methylate histone H3 at lysine 27 (H3K27me3) and elicit gene silencing. Here we demonstrate that EZH2 inhibition has differential effects on the TopoII inhibitor response of non-small-cell lung cancers in vitro and in vivo. EGFR and BRG1 mutations are genetic biomarkers that predict enhanced sensitivity to TopoII inhibitor in response to EZH2 inhibition. BRG1 loss-of-function mutant tumours respond to EZH2 inhibition with increased S phase, anaphase bridging, apoptosis and TopoII inhibitor sensitivity. Conversely, EGFR and BRG1 wild-type tumours upregulate BRG1 in response to EZH2 inhibition and ultimately become more resistant to TopoII inhibitor. EGFR gain-of-function mutant tumours are also sensitive to dual EZH2 inhibition and TopoII inhibitor, because of genetic antagonism between EGFR and BRG1. These findings suggest an opportunity for precision medicine in the genetically complex disease of non-small-cell lung cancer.

Near-Null Magnetic Field Suppresses Fruit Growth in Arabidopsis.

We previously found that a near-null magnetic field affected reproductive growth in Arabidopsis under white light. To test whether the effect of a near-null magnetic field on fruit growth of Arabidopsis is related to cryptochrome, we grew wild-type Arabidopsis and cryptochrome double mutant, cry1/cry2, in a near-null magnetic field under blue light. We found that fruit growth of wild-type Arabidopsis instead of the cry1/cry2 mutant was suppressed by the near-null magnetic field. Furthermore, gibberellin (GA) levels of GA4 , GA9 , GA34 , and GA51 in fruits of wild-type plants in the near-null magnetic fields were significantly lower than local geomagnetic field controls. However, in cry1/cry2 mutants, levels of the four detected GAs in fruits in the near-null magnetic fields did not differ significantly from controls. Expressions of GA20-oxidase (GA20ox) genes (GA20ox1 and GA20ox2) and GA3-oxidase (GA3ox) genes (GA3ox1 and GA3ox3) in fruits of wild-type plants rather than cry1/cry2 mutants were downregulated by the near-null magnetic field. In contrast, expressions of GA2-oxidase (GA2ox) genes and GA signaling genes were not affected by the near-null magnetic field. These results indicate that suppression of fruit growth by the near-null magnetic field is mediated by cryptochrome and that GAs are involved in the regulation of fruit growth by the near-null magnetic field. © 2021 Bioelectromagnetics Society.

[Evaluation of effects of salt reducing intervention among catering units in Shandong Province].

OBJECTIVE: To evaluate the effects of comprehensive intervention measures mainly consisting of salt reduction health education and labeling less salt foods among catering units. METHODS: The total of 36 catering units were selected randomly and divided into intervention group A, B and control group in August of 2015. Health education was initiated in the intervention group A, including the training of knowledge on salt reduction for managers, cooks and service personnel of catering units every month; distribution of special salt control spoon for cooks; the arrangement of environment of salt reduction in catering units. And health education and labeling less salt foods was provided to the intervention group B, The control group C did not actively provide any intervention. The cook records the quantity of low-salt dishes sold, salt collection and the number of persons per meal in according to the requirements. Questionnaire survey and physical examination were performed to evaluate the effects of comprehensive intervention measures among catering units in the three groups of staffs in the catering units in a baseline study and an evaluation survey six months after the intervention. RESULTS: Compared with group C, the knowledge, attitude and behavior of salt reduction was significantly improved in intervention group A and B(P<0. 05). The behavior towards salt reduction improved much better in group B than in group A(P<0. 05), and using salt spoon when cooking and recommending less salt food to customer improved 32. 1%(χ~2=51. 72, P<0. 05)and 24. 2%(χ~2=30. 01, P<0. 05)separately. The proportion of sales of low salt dishes in the unit canteen has increased steadily, reaching 16. 8% while the proportion of sales has dropped to 9. 2% in the hotel by the end of the intervention period(χ~2=44. 66, P<0. 05). CONCLUSION: The level of knowledge of reducing salt was improved by health education, and labeling less salt foods can promote reducing salt related behavior. The effect of comprehensive intervention measures for salt reduction in unit canteen is better than in the hotel. It was suggested that comprehensive intervention measures mainly consisting of salt reduction health education and labeling less salt foods should be used together in the catering units.

Development and optimization of genetic toolboxes for a fast-growing cyanobacterium Synechococcus elongatus UTEX 2973.

The fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (hereafter Synechococcus 2973) has been considered a good chassis candidate for "microbial cell factory" as it can perform oxygenic photosynthesis and its doubling time can be as short as 1.9 h. However, the limited genetic tools currently restrict its further research and application efforts using synthetic biology approaches. In this study, a series of genetic tools were systematically developed and optimized for Synechococcus 2973. First, the introduction of Tfp pilus assembly protein encoding gene pilN into Synechococcus 2973 successfully recovered its natural transformability, which greatly simplified the DNA transformation process. Second, a series of promoters with different strengths were evaluated and the super-strong promoters including Pcpc560 from Synechocystis sp. PCC 6803, native PpsbA2 and PpsbA3 of Synechococcus 2973 were found with the highest activity of ß-galactosidase among those evaluated by miller values. Some promoters related to photosystems (i.e., PpsbA2, PpsbA3, P6803psbA2 and Pcpc560) were also demonstrated to be induced by high intensity of light. Third, three lactose induction systems were evaluated, among which Plac combined with lacIq showed the best application prospect with great induction capacity, low leakage and middle induced expression. Fourth, the translational on riboswitch theoE* , the transcriptional off riboswitches theo/yitJ and xpt(C74U)/metE and an artificial inducing system combining theoE* with T7 RNA polymerase were successfully developed and characterized in Synechococcus 2973. Finally, by using T7 induction system to control the expression of both small RNA and chaperone Hfq, a small RNA regulatory tool was developed and optimized to be a strictly inducible off system for gene regulation in Synechococcus 2973. The work here presented valuable genetic toolboxes necessary for metabolic engineering and synthetic biology research in Synechococcus 2973, which will facilitate the future application of the fast growing cyanobacterial chassis.

A murine lung cancer co-clinical trial identifies genetic modifiers of therapeutic response.

Targeted therapies have demonstrated efficacy against specific subsets of molecularly defined cancers. Although most patients with lung cancer are stratified according to a single oncogenic driver, cancers harbouring identical activating genetic mutations show large variations in their responses to the same targeted therapy. The biology underlying this heterogeneity is not well understood, and the impact of co-existing genetic mutations, especially the loss of tumour suppressors, has not been fully explored. Here we use genetically engineered mouse models to conduct a 'co-clinical' trial that mirrors an ongoing human clinical trial in patients with KRAS-mutant lung cancers. This trial aims to determine if the MEK inhibitor selumetinib (AZD6244) increases the efficacy of docetaxel, a standard of care chemotherapy. Our studies demonstrate that concomitant loss of either p53 (also known as Tp53) or Lkb1 (also known as Stk11), two clinically relevant tumour suppressors, markedly impaired the response of Kras-mutant cancers to docetaxel monotherapy. We observed that the addition of selumetinib provided substantial benefit for mice with lung cancer caused by Kras and Kras and p53 mutations, but mice with Kras and Lkb1 mutations had primary resistance to this combination therapy. Pharmacodynamic studies, including positron-emission tomography (PET) and computed tomography (CT), identified biological markers in mice and patients that provide a rationale for the differential efficacy of these therapies in the different genotypes. These co-clinical results identify predictive genetic biomarkers that should be validated by interrogating samples from patients enrolled on the concurrent clinical trial. These studies also highlight the rationale for synchronous co-clinical trials, not only to anticipate the results of ongoing human clinical trials, but also to generate clinically relevant hypotheses that can inform the analysis and design of human studies.

Suppression of Arabidopsis flowering by near-null magnetic field is mediated by auxin.

We previously found that flowering of Arabidopsis was suppressed by near-null magnetic field, which was related to cryptochrome. Auxin plays an important role in Arabidopsis flowering. To test whether auxin is involved in the suppression of Arabidopsis flowering by near-null magnetic field, we detected auxin level and expressions of auxin transport and signaling genes in wild-type Arabidopsis plants and cryptochrome double mutant, cry1/cry2, grown in near-null magnetic field. We found that indole-3-acetic acid (IAA) level in roots of wild-type plants in near-null magnetic field was significantly increased compared with the local geomagnetic field control, while IAA level in rosettes of 33-day-old wild-type plants in near-null magnetic field was significantly lower than the control. Expressions of three auxin transporter genes, PIN1, PIN3, and PIN7, in wild-type plants were upregulated by near-null magnetic field. Transcript levels of transcriptional repressor genes, IAA1, IAA5, IAA6, IAA16, and IAA19, were significantly higher in wild-type plants in near-null magnetic field than in control plants. However, IAA level and expressions of all the detected genes in cry1/cry2 mutants in near-null magnetic field were similar to controls. Our results suggest that near-null magnetic field affects the distribution of auxin in Arabidopsis by transcriptional upregulation of auxin transporter genes, and that change in distribution of auxin and increased expressions of transcriptional repressor genes result in delay of flowering in Arabidopsis in near-null magnetic field, which are mediated by cryptochrome. Bioelectromagnetics. 39:15-24, 2018. © 2017 Wiley Periodicals, Inc.

Susceptibility loci for metabolic syndrome and metabolic components identified in Han Chinese: a multi-stage genome-wide association study.

Metabolic syndrome (MetS), a cluster of metabolic disturbances that increase the risk for cardiovascular disease and diabetes, was because of genetic susceptibility and environmental risk factors. To identify the genetic variants associated with MetS and metabolic components, we conducted a genome-wide association study followed by replications in totally 12,720 participants from the north, north-eastern and eastern China. In combined analyses, independent of the top known signal at rs651821 on APOA5, we newly identified a secondary triglyceride-associated signal at rs180326 on BUD13 (Pcombined = 2.4 × 10-8 ). Notably, by an integrated analysis of the genotypes and the serum levels of APOA5, BUD13 and triglyceride, we observed that BUD13 was another potential mediator, besides APOA5, of the association between rs651821 and serum triglyceride. rs671 (ALDH2), an east Asian-specific common variant, was found to be associated with MetS (Pcombined = 9.7 × 10-22 ) in Han Chinese. The effects of rs671 on metabolic components were more prominent in drinkers than in non-drinkers. The replicated loci provided information on the genetic basis and mechanisms of MetS and metabolic components in Han Chinese.

Gender disparity in the associations of overweight/obesity with occupational activity, transport to/from work, leisure-time physical activity, and leisure-time spent sitting in working adults: A cross-sectional study.

BACKGROUND: The associations of occupational activity (OA), commuting, leisure-time physical activity (LTPA), and sitting with overweight/obesity in working adults are controversial. This study explored these factors with the risk of overall and abdominal overweight/obesity in a Chinese working population and whether these associations differ by gender. METHODS: A cross-sectional study was conducted. Data analysis was done among 6739 employed participants. Multivariate logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the studied associations. RESULTS: For male employees, those with heavy OA had a lower overall (OR 0.76; 95% CI, 0.62-0.93) and abdominal (OR 0.76; 95% CI, 0.62-0.93) overweight/obesity risk than those with light OA. Those with LTPA ≥150 min/week had a lower risk of overall (OR 0.73; 95% CI, 0.56-0.96) and abdominal (OR 0.70; 95% CI, 0.53-0.91) overweight/obesity than those with LTPA <150 min/week. Men with leisure-sitting time <2.5 h/day had a significantly lower risk of abdominal overweight/obesity than those sitting ≥4 h/day (OR 0.80; 95% CI, 0.65-0.99). And men who cycled to/from work had a lower risk of overall (OR 0.69; 95% CI, 0.53-0.90) and abdominal overweight/obesity (OR 0.71; 95% CI, 0.54-0.92) than passive transports. However, the above significant associations disappeared among female employees. CONCLUSIONS: Heavy OA, cycling to/from work, and LTPA were associated with lower risk of overall or abdominal overweight/obesity in male employees. Reducing leisure sitting time can also help male employees reduce the risk of abdominal overweight/obesity. More research on gender disparity in the risk of overweight and obesity should be done.

Gibberellins are involved in effect of near-null magnetic field on Arabidopsis flowering.

We previously found that flowering of Arabidopsis was suppressed by near-null magnetic field, which was related to the modification of cryptochrome. To disclose the physiological mechanism of this effect, we detected gibberellin (GA) levels and expressions of GA biosynthetic and signaling genes in wild type Arabidopsis plants and cryptochrome double mutant, cry1/cry2, grown in near-null magnetic field. We found that levels of GA4 , GA9 , GA34 , and GA51 in wild type plants in near-null magnetic field were significantly decreased compared with local geomagnetic field controls. However, GA levels in cry1/cry2 mutants in near-null magnetic field were similar to controls. Expressions of three GA20-oxidase (GA20ox) genes (GA20ox1, GA20ox2, and GA20ox3) and four GA3-oxidase (GA3ox) genes (GA3ox1, GA3ox2, GA3ox3, and GA3ox4) in wild type plants in near-null magnetic field were significantly reduced compared with controls, while expressions of GA20ox4, GA20ox5, GA2-oxidase (GA2ox) genes, and GA signaling-related genes in wild type plants in near-null magnetic field were not significantly different from controls. In contrast, expressions of all the detected GA biosynthetic and signaling genes in cry1/cry2 mutants were not affected by near-null magnetic field. Moreover, transcriptions of flowering-related genes, LFY and SOC1, in wild type plants were downregulated by near-null magnetic field, while they were not affected by near-null magnetic field in cry1/cry2 mutants. Our results suggest that the effect of near-null magnetic field on Arabidopsis flowering is GA-related, which is caused by cryptochrome-involved suppression of GA biosynthesis. Bioelectromagnetics. 38:1-10, 2017. © 2016 Wiley Periodicals, Inc.

A novel variant on chromosome 6p21.1 is associated with the risk of developing colorectal cancer: a two-stage case-control study in Han Chinese.

BACKGROUND: Genes in inflammatory pathways play a pivotal role in the development of colorectal cancer. We conducted a two-stage case-control study and aimed at screening the colorectal cancer-associated genetic variations in inflammatory genes. METHODS: Twenty-three candidate variants were genotyped in 952 primary colorectal cancer cases and 875 cancer-free controls from eastern China. Promising single nucleotide polymorphisms were further genotyped in 518 cases and 554 controls from middle China. Expression quantitative trait loci and differential gene expression analyses were performed for the associated gene. RESULTS: rs2282151 presented consistently significant associations with the risk of colorectal cancer in both stages (odds ratio (95 % confidence interval) = 1.30 (1.16-1.46), risk allele = C, P combined = 8.9E-6). Gene expression quantitative trait loci analyzes uncovered consistent cis-regulatory signals which showed that the C allele of rs2282151 was associated with increased expression level of heat shock protein 90 alpha family class B member 1 (HSP90AB1). Then we found that the mRNA expression levels of HSP90AB1 were significantly higher in tumor tissues than normal tissues (fold-change = 1.83) in 28 pairs of colorectal tissue samples. The expression difference was consistent with data from online datasets. Additionally, we observed notable peaks of H3K27ac and H3K4me3 near the first intron of HSP90AB1 using ChIP-seq data from multiple cell lines (including HCT116). CONCLUSIONS: Our findings indicate that the C allele of the novel colorectal cancer-associated variant rs2282151 is associated with increased expression levels of HSP90AB1, which is expressed higher in colorectal tumor tissues than in normal tissues.

Iodine nutritional status in the adult population of Shandong Province (China) prior to salt reduction program.

PURPOSE: Tremendous differences in iodine status and daily iodine intake persist across provinces of China. The objective of the present study was to evaluate the iodine status and dietary iodine intake of Shandong adults before the implementation of the salt reduction program and a new salt iodization standard. METHODS: Data from a baseline survey of the Shandong and Ministry of Health Action on Salt Reduction and Hypertension project (2011) were analyzed. The iodine contents of 1949 24-h urine samples and 136 drinking water samples were assayed. Daily urinary iodine excretion and daily iodine intake were calculated, analyzed, stratified by different analytical variables and compared with Chinese Dietary Reference Values. RESULTS: The median urinary iodine concentration and median daily iodine intake of Shandong adults were 248.5 µg/L and 368.2 µg/day, respectively. The median iodine intake of different groups was between the estimated average requirements and the upper limit, except group in water iodine >300 µg/L with median iodine intake of 1200.7 µg/L. Salt intake and iodine levels in drinking water related to iodine intake significantly. CONCLUSIONS: Shandong adults had more than adequate iodine nutrition, and the dietary iodine intake of the population was generally appropriate and safe except residents in high water iodine areas. In the context of the implementation of a salt reduction program and a new salt iodization standard, the iodine status of high water iodine areas may remain in the recommended level, but in low water iodine areas, the risk of inadequate iodine intake may increase, needing monitoring of urine iodine excretion, dietary iodine intake and iodized salt consumption regularly.

STOP gene Phactr4 is a tumor suppressor.

Cancer develops through genetic and epigenetic alterations that allow unrestrained proliferation and increased survival. Using a genetic RNAi screen, we previously identified hundreds of suppressors of tumorigenesis and/or proliferation (STOP) genes that restrain normal cell proliferation. Our STOP gene set was significantly enriched for known and putative tumor suppressor genes. Here, we report a tumor-suppressive role for one STOP gene, phosphatase and actin regulator 4 (PHACTR4). Phactr4 is one of four members of the largely uncharacterized Phactr family of protein phosphatase 1 (PP1)-and actin-binding proteins. Our work suggests that Phactr4 restrains normal cell proliferation and transformation. Depletion of Phactr4 with multiple shRNAs leads to increased proliferation and soft agar colony formation. Phactr4 acts, in part, through an Rb-dependent pathway, because Rb phosphorylation is maintained upon growth factor withdrawal in Phactr4-depleted cells. Examination of tumor copy number analysis and sequencing revealed that PHACTR4 is significantly deleted and mutant in many tumor subtypes. Furthermore,cancer cell lines with reduced Phactr4 expression exhibit tumor suppressor hypersensitivity upon Phactr4 complementation,leading to reduced proliferation, transformation, and tumor formation. Thus, Phactr4 acts as a tumor suppressor that is deleted and mutant in several cancers.

STING agonists induce an innate antiviral immune response against hepatitis B virus.

Chronicity of hepatitis B virus (HBV) infection is due to the failure of a host to mount a sufficient immune response to clear the virus. The aim of this study was to identify small-molecular agonists of the pattern recognition receptor (PRR)-mediated innate immune response to control HBV infection. To achieve this goal, a coupled mouse macrophage and hepatocyte culture system mimicking the intrahepatic environment was established and used to screen small-molecular compounds that activate macrophages to produce cytokines, which in turn suppress HBV replication in a hepatocyte-derived stable cell line supporting HBV replication in a tetracycline-inducible manner. An agonist of the mouse stimulator of interferon (IFN) genes (STING), 5,6-dimethylxanthenone-4-acetic acid (DMXAA), was found to induce a robust cytokine response in macrophages that efficiently suppressed HBV replication in mouse hepatocytes by reducing the amount of cytoplasmic viral nucleocapsids. Profiling of cytokines induced by DMXAA and agonists of representative Toll-like receptors (TLRs) in mouse macrophages revealed that, unlike TLR agonists that induced a predominant inflammatory cytokine/chemokine response, the STING agonist induced a cytokine response dominated by type I IFNs. Moreover, as demonstrated in an HBV hydrodynamic mouse model, intraperitoneal administration of DMXAA significantly induced the expression of IFN-stimulated genes and reduced HBV DNA replication intermediates in the livers of mice. This study thus proves the concept that activation of the STING pathway induces an antiviral cytokine response against HBV and that the development of small-molecular human STING agonists as immunotherapeutic agents for treatment of chronic hepatitis B is warranted.

Alpha-interferon suppresses hepadnavirus transcription by altering epigenetic modification of cccDNA minichromosomes.

Covalently closed circular DNA (cccDNA) of hepadnaviruses exists as an episomal minichromosome in the nucleus of infected hepatocyte and serves as the transcriptional template for viral mRNA synthesis. Elimination of cccDNA is the prerequisite for either a therapeutic cure or immunological resolution of HBV infection. Although accumulating evidence suggests that inflammatory cytokines-mediated cure of virally infected hepatocytes does occur and plays an essential role in the resolution of an acute HBV infection, the molecular mechanism by which the cytokines eliminate cccDNA and/or suppress its transcription remains elusive. This is largely due to the lack of convenient cell culture systems supporting efficient HBV infection and cccDNA formation to allow detailed molecular analyses. In this study, we took the advantage of a chicken hepatoma cell line that supports tetracycline-inducible duck hepatitis B virus (DHBV) replication and established an experimental condition mimicking the virally infected hepatocytes in which DHBV pregenomic (pg) RNA transcription and DNA replication are solely dependent on cccDNA. This cell culture system allowed us to demonstrate that cccDNA transcription required histone deacetylase activity and IFN-α induced a profound and long-lasting suppression of cccDNA transcription, which required protein synthesis and was associated with the reduction of acetylated histone H3 lysine 9 (H3K9) and 27 (H3K27) in cccDNA minichromosomes. Moreover, IFN-α treatment also induced a delayed response that appeared to accelerate the decay of cccDNA. Our studies have thus shed light on the molecular mechanism by which IFN-α noncytolytically controls hepadnavirus infection.

Muscle MRI in neutral lipid storage disease with myopathy carrying mutation c.187+1G>A.

INTRODUCTION: We describe the clinical and muscle MRI changes in 2 siblings with neutral lipid storage disease with myopathy (NLSDM) carrying the mutation c.187+1G>A. METHODS: Peripheral blood smears, genetic tests, and muscle biopsies were performed. Thigh MRI was performed to observe fatty replacement, muscle edema, and muscle bulk from axial sections. RESULTS: Both siblings had similar fatty infiltration and edema. T1-weighted images of the gluteus maximus, adductor magnus, semitendinosus, and semimembranosus revealed marked and diffuse fatty infiltration. There was asymmetric involvement in biceps femoris and quadriceps. There was extensive fatty infiltration in the quadriceps, except for the rectus femoris. Gracilis and sartorius were relatively spared. Thigh muscle volume was decreased, while the gracilis and sartorius appeared to show compensatory hypertrophy. CONCLUSIONS: Compared with previous reports in NLSDM, MRI changes in this myopathy tended to be more severe. Asymmetry and relatively selective fatty infiltration were characteristics.

Enantioselective Synthesis of Dioxatriquinane Structural Motifs for HIV-1 Protease Inhibitors Using a Cascade Radical Cyclization.

Synthesis of novel HIV-1 protease inhibitors incorporating dioxatriquinane-derived P2-ligands is described. The tricyclic ligand alcohol contains five contiguous chiral centers. The ligand alcohols were prepared in optically active form by an enzymatic asymmetrization of mesodiacetate, cascade radical cyclization, and Lewis acid catalyzed reduction as the key steps. Inhibitors with dioxatriquinane-derived P2-ligands exhibited low nanomolar HIV-1 protease activity.