Two New Ergosterol Derivatives from the Basidiomycete Cortinarius glaucopus

Two new sterols 1 and 2 and five known ones 3 – 7 were isolated for the first time from the fruiting bodies of Cortinarius glaucopus. Their structures were established by 1‐ and 2D‐NMR spectra and HR‐FABS‐MS. The relative configuration of 1 was firmly determined by comparison of the observed ¹H–¹H couplings and NOESY correlations, with those predicted for the computed geometries of the conformers. Calculations were performed by means of DFT with the B3LYP functional at 6‐31 + G(d,p) level of theory, in CHCl₃ as the solvent. The structures of the new ergosterol derivatives, called glaucoposterol A ( 1 ) and B ( 2 ), were thus established as (3S,5R,7R,10R,13R,17R,20S,22R,23R,24R)‐5,6‐epoxy‐3,7,23‐trihydroxystrophast‐8‐en‐14‐one and (22E,3S,5S,9S,10R,13R,17R,20R,24R)‐3,5‐dihydroxyergosta‐6,8(14),22‐trien‐15‐one, respectively. Moreover, the configuration of known strophasterol C ( 3 ) was determined as (3S,5R,6S,7R,10R,13R,17R,20S,22S,24R). Glaucoposterol A ( 1 ) and strophasterol C ( 3 ) represent the second finding in nature of steroids with the rare strophastane skeleton.     

Malaria Burden and Artemisinin Resistance in the Mobile and Migrant Population on the Thai–Myanmar Border, 1999–2011: An Observational Study

Background

The Shoklo Malaria Research Unit has been working on the Thai–Myanmar border for 25 y providing early diagnosis and treatment (EDT) of malaria. Transmission of Plasmodium falciparum has declined, but resistance to artesunate has emerged. We expanded malaria activities through EDT and evaluated the impact over a 12-y period.

Methods and Findings

Between 1 October 1999 and 30 September 2011, the Shoklo Malaria Research Unit increased the number of cross-border (Myanmar side) health facilities from two to 11 and recorded the number of malaria consultations. Changes in malaria incidence were estimated from a cohort of pregnant women, and prevalence from cross-sectional surveys. In vivo and in vitro antimalarial drug efficacy were monitored. Over this period, the number of malaria cases detected increased initially, but then declined rapidly. In children under 5 y, the percentage of consultations due to malaria declined from 78% (95% CI 76–80) (1,048/1,344 consultations) to 7% (95% CI 6.2–7.1) (767/11,542 consultations), p<0.001. The ratio of P. falciparum/P. vivax declined from 1.4 (95% CI 1.3–1.4) to 0.7 (95% CI 0.7–0.8). The case fatality rate was low (39/75,126; 0.05% [95% CI 0.04–0.07]). The incidence of malaria declined from 1.1 to 0.1 episodes per pregnant women-year. The cumulative proportion of P. falciparum decreased significantly from 24.3% (95% CI 21.0–28.0) (143/588 pregnant women) to 3.4% (95% CI 2.8–4.3) (76/2,207 pregnant women), p<0.001. The in vivo efficacy of mefloquine-artesunate declined steadily, with a sharp drop in 2011 (day-42 PCR-adjusted cure rate 42% [95% CI 20–62]). The proportion of patients still slide positive for malaria at day 3 rose from 0% in 2000 to reach 28% (95% CI 13–45) (8/29 patients) in 2011.

Conclusions

Despite the emergence of resistance to artesunate in P. falciparum, the strategy of EDT with artemisinin-based combination treatments has been associated with a reduction in malaria in the migrant population living on the Thai–Myanmar border. Although limited by its observational nature, this study provides useful data on malaria burden in a strategically crucial geographical area. Alternative fixed combination treatments are needed urgently to replace the failing first-line regimen of mefloquine and artesunate. Please see later in the article for the Editors'' Summary     

Whole-Genome Sequencing of Aspergillus terreus Species Complex

Mycopathologia - Aspergillus terreus species complex is an opportunistic fungal pathogen increasingly implicated in invasive infection, as well as chronic respiratory disease. Currently, an...     

Control of Adipogenesis by the Autocrine Interplays between Angiotensin 1–7/Mas Receptor and Angiotensin II/AT1 Receptor Signaling Pathways

Angiotensin II (AngII), a peptide hormone released by adipocytes, can be catabolized by adipose angiotensin-converting enzyme 2 (ACE2) to form Ang(1–7). Co-expression of AngII receptors (AT₁ and AT₂) and Ang(1–7) receptors (Mas) in adipocytes implies the autocrine regulation of the local angiotensin system upon adipocyte functions, through yet unknown interactive mechanisms. In the present study, we reveal the adipogenic effects of Ang(1–7) through activation of Mas receptor and its subtle interplays with the antiadipogenic AngII-AT1 signaling pathways. Specifically, in human and 3T3-L1 preadipocytes, Ang(1–7)-Mas signaling promotes adipogenesis via activation of PI3K/Akt and inhibition of MAPK kinase/ERK pathways, and Ang(1–7)-Mas antagonizes the antiadipogenic effect of AngII-AT₁ by inhibiting the AngII-AT₁-triggered MAPK kinase/ERK pathway. The autocrine regulation of the AngII/AT₁-ACE2-Ang(1–7)/Mas axis upon adipogenesis has also been revealed. This study suggests the importance of the local regulation of the delicately balanced angiotensin system upon adipogenesis and its potential as a novel therapeutic target for obesity and related metabolic disorders.     

Germline Mutations in the Polyposis-Associated Genes BMPR1A,SMAD4, PTEN,MUTYH and GREM1 Are Not Common in Individuals with Serrated Polyposis Syndrome

Background

Recent reports have observed that individuals with serrated polyps, some of whom meet the clinical diagnostic criteria for Serrated Polyposis Syndrome (SPS), are among those who carry germline mutations in genes associated with polyposis syndromes including; (1) genes known to underlie hamartomatous polyposes (SMAD4, BMPR1A, and PTEN), (2) MUTYH-associated polyposis and (3) GREM1 in Hereditary Mixed Polyposis Syndrome (HMPS). The aim of this study was to characterise individuals fulfilling the current WHO criteria for SPS for germline mutations in these polyposis-associated genes.

Methods

A total of 65 individuals with SPS (fulfilling WHO criteria 1 or 3), were recruited to the Genetics of Serrated Neoplasia study between 2000 and 2012, through multiple Genetics or Family Cancer Clinics within Australia, or from the New Zealand Familial Gastrointestinal Cancer Service. Individuals with SPS were tested for coding mutations and large deletions in the PTEN, SMAD4, and BMPR1A genes, for the MUTYH variants in exons 7 (Y179C) and 13 (G396D), and for the duplication upstream of GREM1.

Results

We found no variants that were likely to be deleterious germline mutations in the SPS cases in the PTEN, SMAD4, and BMPR1A genes. A novel variant in intron 2 (c.164+223T>C) of PTEN was identified in one individual and was predicted by in silico analysis to have no functional consequences. One further individual with SPS was found to be mono-allelic for the MUTYH G396D mutation. No individuals carried the recently reported duplication within GREM1.

Conclusions

Genes involved in the gastrointestinal hamartomatous polyposis, Hereditary Mixed Polyposis Syndrome and MUTYH-associated polyposis syndromes are not commonly altered in individuals with SPS.     

Germline HOXB13 p.Gly84Glu mutation and risk of colorectal cancer

Introduction: The HOXB13 pGly84Glu mutation has recently been associated with an increased risk of prostate cancer but the association of other cancer sites with this allele has not been assessed. Data has suggested that HOXB13 expression levels are decreased in colorectal cancer (CRC) cell lines indicating this gene may be involved in colorectal tumourigenesis. Methods: To evaluate a potential association of this mutation with CRC, we genotyped the mutation in 2695 CRC cases and 4593 controls from population-based registries in Canada and Australia. Results: The HOXB13 pGly84Glu mutation was more common in CRC cases than controls (0.48% vs. 0.17%, P = 0.02) indicating a significant association between the HOXB13 variant and CRC risk (OR = 2.8; 95%CI: 1.2–6.8). This association was attenuated but remained significant with the inclusion of previously published and publicly available genotype data. Pedigree analysis of cases and controls revealed that 7/21 HOXB13 mutation carriers had a family history of prostate cancer. Discussion: This report is the first to suggest a risk of CRC associated with mutations in the HOXB13 gene. These findings require further validation but may be of importance in the screening and genetic counseling of families known to carry the HOXB13 pGly84Glu mutation.     

Reducing salt intake for prevention of cardiovascular diseases in high-risk patients by advanced health education intervention (RESIP-CVD study), Northern Thailand: study protocol for a cluster randomized trial

ABSTRACT: BACKGROUND: Decreasing salt consumption can prevent cardiovascular diseases (CVD). Practically, it is difficult to promote people's awareness of daily salt intake and to change their eating habits in terms of reducing salt intake for better cardiovascular health. Health education programs visualizing daily dietary salt content and intake may promote lifestyle changes in patients at high risk of cardiovascular disease. METHODS: This is a cluster randomized trial. A total of 800 high-CVD-risk patients attending diabetes and hypertension clinics at health centers in Muang District, Chiang Rai province, Thailand, will be studied with informed consent. A health center recruiting 100 participants is a cluster, the unit of randomization. Eight clusters will be randomized into intervention and control arms and followed up for 1 year. Within the intervention clusters the following will be undertaken: (1) salt content in the daily diet will be measured and shown to study participants; (2) 24-hour salt intake will be estimated in overnight-collected urine and the results shown to the participants; (3) a dietician will assist small group health education classes in cooking meals with less salt. The primary outcome is blood pressure change at the 1-year follow-up. Secondary outcomes at the 1-year follow-up are estimated 24-hoursalt intake, incidence of CVD events and CVD death. The intention-to-treat analysis will be followed.Blood pressure and estimated 24-hour salt intake will be compared between intervention and control groups at the cluster and individual level at the 1-year follow-up. Clinical CVD events and deaths will be analyzed by time-event analysis. Retinal blood vessel calibers of CVD-risk patients will be assessed cross-sectionally. Behavioral change to reduce salt intake and the influencing factors will be determined by structured equation model (SEM). Multilevel regression analyses will be applied. Finally, the cost effectiveness of the intervention will be analyzed. DISCUSSION: This study is unique as it will recruit the individuals most vulnerable to CVD morbidity and mortality by applying the general Framingham CVD risk scoring system. Dietary salt reduction will be applied as a prioritized, community level intervention for the prevention of CVD in a developing country.Trial registrationISRCTN39416277.     

Co-Regulation of Cell Polarization and Migration by Caveolar Proteins PTRF/Cavin-1 and Caveolin-1

Caveolin-1 and caveolae are differentially polarized in migrating cells in various models, and caveolin-1 expression has been shown to quantitatively modulate cell migration. PTRF/cavin-1 is a cytoplasmic protein now established to be also necessary for caveola formation. Here we tested the effect of PTRF expression on cell migration. Using fluorescence imaging, quantitative proteomics, and cell migration assays we show that PTRF/cavin-1 modulates cellular polarization, and the subcellular localization of Rac1 and caveolin-1 in migrating cells as well as PKCα caveola recruitment. PTRF/cavin-1 quantitatively reduced cell migration, and induced mesenchymal epithelial reversion. Similar to caveolin-1, the polarization of PTRF/cavin-1 was dependent on the migration mode. By selectively manipulating PTRF/cavin-1 and caveolin-1 expression (and therefore caveola formation) in multiple cell systems, we unveil caveola-independent functions for both proteins in cell migration.     

A miRNA involved in phosphate-starvation response in Arabidopsis

Although microRNAs (miRNAs) have been documented to regulate development in plants and animals , the function of miRNAs in physiology is unclear. miR399 has multiple target sites in the 5' untranslated region (UTR) of a gene encoding a putative ubiquitin-conjugating enzyme (UBC) in Arabidopsis thaliana. We report here that miR399 was highly induced, whereas the target UBC mRNA was reduced by low-phosphate (Pi) stress. In transgenic plants with constitutive expression of miR399, UBC mRNA accumulation was suppressed even under high Pi. The expression of transgene UBC mRNA with 5' UTR miR399 target sites, but not the one without 5' UTR, was reduced under low-Pi condition. Furthermore, transgenic Arabidopsis plants with constitutive expression of miR399 accumulated more Pi than the wild-type, and transgenic plants expressing the UBC mRNA without 5' UTR (miRNA-deregulated) showed less inhibition of primary root growth and less induction of a Pi transporter gene by low-Pi stress than those of wild-type plants. We conclude that miR399 downregulates UBC mRNA accumulation by targeting the 5' UTR, and this regulation is important for plant responses to Pi starvation. The results suggest that miRNAs have functional roles for plants to cope with fluctuations in mineral-nutrient availability in the soil.