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Coptis chinensis is an ancient Chinese herb treating diabetes in China for thousands of years. However, its underlying mechanism remains poorly understood. Here, we report the effects of its main active component, berberine (BBR), on stimulating insulin secretion. In mice with hyperglycemia induced by a high-fat diet, BBR significantly increases insulin secretion and reduced blood glucose levels. However, in mice with hyperglycemia induced by global or pancreatic islet β-cell-specific Kcnh6 knockout, BBR does not exert beneficial effects. BBR directly binds KCNH6 potassium channels, significantly accelerates channel closure, and subsequently reduces KCNH6 currents. Consequently, blocking KCNH6 currents prolongs high glucose-dependent cell membrane depolarization and increases insulin secretion. Finally, to assess the effect of BBR on insulin secretion in humans, a randomized, double-blind, placebo-controlled, two-period crossover, single-dose, phase 1 clinical trial (NCT03972215) including 15 healthy men receiving a 160-min hyperglycemic clamp experiment is performed. The pre-specified primary outcomes are assessment of the differences of serum insulin and C-peptide levels between BBR and placebo treatment groups during the hyperglycemic clamp study. BBR significantly promotes insulin secretion under hyperglycemic state comparing with placebo treatment, while does not affect basal insulin secretion in humans. All subjects tolerate BBR well, and we observe no side effects in the 14-day follow up period. In this study, we identify BBR as a glucose-dependent insulin secretagogue for treating diabetes without causing hypoglycemia that targets KCNH6 channels. Berberine is a compound with glucose-lowering effects in mice and humans. Here, the authors show that in mice berberine has beneficial glycemic effects by promoting insulin secretion, which requires the potassium channel KCNH6 in beta cells, and that berberine can promote insulin secretion in healthy men in a phase 1 clinical trial.

The known oxygenated polyhalogenated diphenyl ether, 2-(2′,4′-dibromophenoxy)-3,5-dibromophenol (1), with previously reported activity in multiple cytotoxicity assays was isolated from the sponge Lamellodysidea sp. and proved to be an amenable scaffold for semisynthetic library generation. The phenol group of 1 was targeted to generate 12 ether analogues in low-to-excellent yields, and the new library was fully characterized by NMR, UV, and MS analyses. The chemical structures for 2, 8, and 9 were additionally determined via single-crystal X-ray diffraction analysis. All natural and semisynthetic compounds were evaluated for their ability to inhibit the growth of DU145, LNCaP, MCF-7, and MDA-MB-231 cancer cell lines. Compound 3 was shown to have near-equivalent activity compared to scaffold 1 in two in vitro assays, and the activity of the compounds with an additional benzyl ring appeared to be reliant on the presence and position of additional halogens.

Background: Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in consumer products and are ubiquitous in residential indoor air and dust. However, little is known about exposure in the office environment. Objectives: We examined relationships between PBDE concentrations in the office environment and internal exposure using concurrent measurements of PBDEs in serum, handwipes, and office dust. Methods: We collected serum, dust, and handwipe samples from 31 participants who spent at least 20 hr/week in an office. We used a questionnaire to collect information about work and personal habits. Results: We found positive associations between PBDEs in room dust, handwipes (a measure of personal exposure), and serum. PBDE office dust concentrations were weakly correlated with measurements in handwipes: r = 0.35 (p = 0.06) for pentaBDE (sum of BDE congeners 28/33, 47, 99, 100, and 153) and 0.33 (p = 0.07) for BDE-209. Hand washing also predicted pentaBDE levels in handwipes: low hand-washers had 3.3 times the pentaBDE levels in their handwipes than did high hand-washers (p = 0.02). PentaBDE in handwipes predicted pentaBDE levels in serum (p = 0.03): Serum concentrations in the highest handwipe tertile were on average 3.5 times the lowest hand-wipe tertile. The geometric mean concentration of pentaBDEs in serum was 27 ng/g lipid. We detected BDE-209 in 20% of serum samples, at levels ranging from < 4.8 to 9.7 ng/g lipid. Conclusion: Our research suggests that exposure to pentaBDE in the office environment contributes to pentaBDE body burden, with exposure likely linked to PBDE residues on hands. In addition, hand washing may decrease exposure to PBDEs.

Current standard of care for trigeminal neuralgia is treatment with the sodium channel blockers carbamazepine and oxcarbazepine, which although effective are associated with poor tolerability and the need for titration. BIIB074, a Nav1.7-selective, state-dependent sodium-channel blocker, can be administered at therapeutic doses without titration, and has shown good tolerability in healthy individuals in phase 1 studies. We therefore assessed the safety and efficacy of BIIB074 in patients with trigeminal neuralgia in a phase 2a study. We did a double-blind, multicentre, placebo-controlled, randomised withdrawal phase 2a trial in 25 secondary care centres in Denmark, Estonia, France, Germany, Italy, Latvia, Lithuania, Romania, South Africa, Spain, Switzerland, and the UK. After a 7-day run-in phase, eligible patients aged 18–80 years with confirmed trigeminal neuralgia received open-label, BIIB074 150 mg three times per day, orally, for 21 days. Patients who met at least one response criteria were then randomly assigned (1:1) to BIIB074 or placebo for up to 28 days in a double-blind phase. We used an interactive web response system to assign patients with a computer-generated schedule, with stratification (presence or absence of existing pain medication). Patients, clinicians, and assessors were masked to treatment allocation. The primary endpoint was the difference between groups in the number of patients classified as treatment failure during the double blind phase assessed in the modified intention-to-treat population. We assessed safety in all patients who received one or more doses of BIIB074. This study is registered with ClinicalTrials.gov (NCT01540630) and EudraCT (2010-023963-16). The first patient was enrolled on April 23, 2012, and the last patient completed the study on February 26, 2014. We enrolled 67 patients into the open-label phase; 44 completed open-label treatment, and 29 were randomly assigned to double-blind treatment (15 to BIIB074 and 14 to placebo). During the double-blind phase, five (33%) patients assigned to BIIB074 versus nine (64%) assigned to placebo were classified as treatment failures (p=0·0974). BIIB074 was well tolerated, with similar adverse events in the double-blind phase to placebo. Headache was the most common adverse event with BIIB074 in the open-label phase (in 13 [19%] of 67 patients), followed by dizziness (in six [9%] patients). In the double-blind phase, headache, pyrexia, nasopharyngitis, sleep disorder, and tremor were the most frequent adverse events in patients assigned to BIIB074 (in one [7%] of 15 patients for each event), and headache, dizziness, diarrhoea, and vomiting were the most frequent adverse events in patients assigned to placebo (in one [7%] of 14 patients for each event). No severe or serious adverse events were reported in the BIIB074 group during the double-blind phase. One patient assigned to placebo reported intestinal adhesions with obstruction as a severe and serious adverse event, which was considered as unrelated to study medication. The primary endpoint of treatment failure was not significantly lower in the BIIB074 group than in the placebo group. However, our findings provide a basis for continued investigation of BIIB074 in patients with trigeminal neuralgia in future clinical trials. Convergence Pharmaceuticals.

Icotinib, an oral EGFR tyrosine kinase inhibitor, had shown antitumour activity and favourable toxicity in early-phase clinical trials. We aimed to investigate whether icotinib is non-inferior to gefitinib in patients with non-small-cell lung cancer. In this randomised, double-blind, phase 3 non-inferiority trial we enrolled patients with advanced non-small-cell lung cancer from 27 sites in China. Eligible patients were those aged 18–75 years who had not responded to one or more platinum-based chemotherapy regimen. Patients were randomly assigned (1:1), using minimisation methods, to receive icotinib (125 mg, three times per day) or gefitinib (250 mg, once per day) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival, analysed in the full analysis set. We analysed EGFR status if tissue samples were available. All investigators, clinicians, and participants were masked to patient distribution. The non-inferiority margin was 1·14; non-inferiority would be established if the upper limit of the 95% CI for the hazard ratio (HR) of gefitinib versus icotinib was less than this margin. This study is registered with ClinicalTrials.gov, number NCT01040780, and the Chinese Clinical Trial Registry, number ChiCTR-TRC-09000506. 400 eligible patients were enrolled between Feb 26, 2009, and Nov 13, 2009; one patient was enrolled by mistake and removed from the study, 200 were assigned to icotinib and 199 to gefitinib. 395 patients were included in the full analysis set (icotinib, n=199; gefitinib, n=196). Icotinib was non-inferior to gefitinib in terms of progression-free survival (HR 0·84, 95% CI 0·67–1·05; median progression-free survival 4·6 months [95% CI 3·5–6·3] vs 3·4 months [2·3–3·8]; p=0·13). The most common adverse events were rash (81 [41%] of 200 patients in the icotinib group vs 98 [49%] of 199 patients in the gefitinib group) and diarrhoea (43 [22%] vs 58 [29%]). Patients given icotinib had less drug-related adverse events than did those given gefitinib (121 [61%] vs 140 [70%]; p=0·046), especially drug-related diarrhoea (37 [19%] vs 55 [28%]; p=0·033). Icotinib could be a new treatment option for pretreated patients with advanced non-small-cell lung cancer. Zhejiang Beta Pharma (China), the Chinese National Key Special Program for Innovative Drugs, the 863 Project, and Zhejiang Provincial Key Special Program.

The voltage-gated potassium channel Eag1 is overexpressed in tumor cells from a range of cancers, and inhibiting Eag1 reduces tumor growth. Whicher and Mackinnon determined the structure of a mammalian Eag1 bound to the inhibitor calmodulin at 3.78 Å resolution (see the Perspective by Toombes and Swartz). The organization of the voltage-sensing and pore domains differs from that of other potassium channels, indicating that the gating mechanism is distinct. The structure also shows how the channel can be closed by a ligand, independently of the position of the voltage sensor. Science , this issue p. 664 ; see also p. 646 Structure of a potassium channel reveals the mechanism of the interplay between voltage-dependent and ligand gating. Voltage-gated potassium (K v ) channels are gated by the movement of the transmembrane voltage sensor, which is coupled, through the helical S4-S5 linker, to the potassium pore. We determined the single-particle cryo–electron microscopy structure of mammalian K v 10.1, or Eag1, bound to the channel inhibitor calmodulin, at 3.78 angstrom resolution. Unlike previous K v structures, the S4-S5 linker of Eag1 is a five-residue loop and the transmembrane segments are not domain swapped, which suggest an alternative mechanism of voltage-dependent gating. Additionally, the structure and position of the S4-S5 linker allow calmodulin to bind to the intracellular domains and to close the potassium pore, independent of voltage-sensor position. The structure reveals an alternative gating mechanism for K v channels and provides a template to further understand the gating properties of Eag1 and related channels.

2,2’4,4’-tetrabromodiphenyl ether (PBDE-47) is one of the most widespread environmental brominated flame-retardant congeners which has also been detected in animal and human tissues. Several studies have reported the effects of PBDEs on different health issues, including neurobehavioral and developmental disorders, reproductive health, and alterations of thyroid function. Much less is known about its immunotoxicity. The aim of our study was to investigate the effects that treatment of THP-1 macrophage-like cells with PBDE-47 could have on the content of small extracellular vesicles’ (sEVs) microRNA (miRNA) cargo and their downstream effects on bystander macrophages. To achieve this, we purified sEVs from PBDE-47 treated M(LPS) THP-1 macrophage-like cells (sEVs PBDE+LPS ) by means of ultra-centrifugation and characterized their miRNA cargo by microarray analysis detecting the modulation of 18 miRNAs. Furthermore, resting THP-1 derived M(0) macrophage-like cells were cultured with sEVs PBDE+LPS , showing that the treatment reshaped the miRNA profiles of 12 intracellular miRNAs. This dataset was studied in silico , identifying the biological pathways affected by these target genes. This analysis identified 12 pathways all involved in the maturation and polarization of macrophages. Therefore, to evaluate whether sEVs PBDE+LPS can have some immunomodulatory activity, naïve M(0) THP-1 macrophage-like cells cultured with purified sEVs PBDE+LPS were studied for IL-6, TNF-α and TGF-β mRNAs expression and immune stained with the HLA-DR, CD80, CCR7, CD38 and CD209 antigens and analyzed by flow cytometry. This analysis showed that the PBDE-47 treatment does not induce the expression of specific M1 and M2 cytokine markers of differentiation and may have impaired the ability to make immunological synapses and present antigens, down-regulating the expression of HLA-DR and CD209 antigens. Overall, our study supports the model that perturbation of miRNA cargo by PBDE-47 treatment contributes to the rewiring of cellular regulatory pathways capable of inducing perturbation of differentiation markers on naïve resting M(0) THP-1 macrophage-like cells.

Saturated oxygen heterocycles are widely found in a broad array of natural products and other biologically active molecules. In medicinal chemistry, small and medium rings are also important synthetic intermediates since they can undergo ring-opening and -expansion reactions. These applications have driven numerous studies on the synthesis of oxygen-containing heterocycles and considerable effort has been devoted toward the development of methods for the construction of saturated oxygen heterocycles. This paper provides an overview of the biological roles and synthetic strategies of saturated cyclic ethers, covering some of the most studied and newly discovered related natural products in recent years. This paper also reports several promising and newly developed synthetic methods, emphasizing 3–7 membered rings.

Hindered ethers are of high value for various applications; however, they remain an underexplored area of chemical space because they are difficult to synthesize via conventional reactions 1 , 2 . Such motifs are highly coveted in medicinal chemistry, because extensive substitution about the ether bond prevents unwanted metabolic processes that can lead to rapid degradation in vivo. Here we report a simple route towards the synthesis of hindered ethers, in which electrochemical oxidation is used to liberate high-energy carbocations from simple carboxylic acids. These reactive carbocation intermediates, which are generated with low electrochemical potentials, capture an alcohol donor under non-acidic conditions; this enables the formation of a range of ethers (more than 80 have been prepared here) that would otherwise be difficult to access. The carbocations can also be intercepted by simple nucleophiles, leading to the formation of hindered alcohols and even alkyl fluorides. This method was evaluated for its ability to circumvent the synthetic bottlenecks encountered in the preparation of 12 chemical scaffolds, leading to higher yields of the required products, in addition to substantial reductions in the number of steps and the amount of labour required to prepare them. The use of molecular probes and the results of kinetic studies support the proposed mechanism and the role of additives under the conditions examined. The reaction manifold that we report here demonstrates the power of electrochemistry to access highly reactive intermediates under mild conditions and, in turn, the substantial improvements in efficiency that can be achieved with these otherwise-inaccessible intermediates. A route to the synthesis of hindered ethers is developed, in which electrochemical oxidation is used to liberate high-energy carbocations that are then captured by an alcohol.

Ferroptosis—an iron-dependent, non-apoptotic cell death process—is involved in various degenerative diseases and represents a targetable susceptibility in certain cancers 1 . The ferroptosis-susceptible cell state can either pre-exist in cells that arise from certain lineages or be acquired during cell-state transitions 2 – 5 . However, precisely how susceptibility to ferroptosis is dynamically regulated remains poorly understood. Here we use genome-wide CRISPR–Cas9 suppressor screens to identify the oxidative organelles peroxisomes as critical contributors to ferroptosis sensitivity in human renal and ovarian carcinoma cells. Using lipidomic profiling we show that peroxisomes contribute to ferroptosis by synthesizing polyunsaturated ether phospholipids (PUFA-ePLs), which act as substrates for lipid peroxidation that, in turn, results in the induction of ferroptosis. Carcinoma cells that are initially sensitive to ferroptosis can switch to a ferroptosis-resistant state in vivo in mice, which is associated with extensive downregulation of PUFA-ePLs. We further find that the pro-ferroptotic role of PUFA-ePLs can be extended beyond neoplastic cells to other cell types, including neurons and cardiomyocytes. Together, our work reveals roles for the peroxisome–ether-phospholipid axis in driving susceptibility to and evasion from ferroptosis, highlights PUFA-ePL as a distinct functional lipid class that is dynamically regulated during cell-state transitions, and suggests multiple regulatory nodes for therapeutic interventions in diseases that involve ferroptosis. The cellular organelles peroxisomes contribute to the sensitivity of cells to ferroptosis by synthesizing polyunsaturated ether phospholipids, and changes in the abundances of these lipids are associated with altered sensitivity to ferroptosis during cell-state transitions.