Intracellular cholesterol stimulates ENaC by interacting with phosphatidylinositol‑4,5‑bisphosphate and mediates cyclosporine A-induced hypertension

We have previously shown that blockade of ATP-binding cassette transporter A1 (ABCA1) with cyclosporine A (CsA) stimulates the epithelial sodium channel (ENaC) in cultured distal nephron cells. Here we show that CsA elevated systolic blood pressure in both wild-type and apolipoprotein E (ApoE) knockout (KO) mice to a similar level. The elevated systolic blood pressure was completely reversed by inhibition of cholesterol (Cho) synthesis with lovastatin. Inside-out patch-clamp data show that intracellular Cho stimulated ENaC in cultured distal nephron cells by interacting with phosphatidylinositol?4,5?bisphosphate (PIP₂), an ENaC activator. Confocal microscopy data show that both α?ENaC and PIP₂ were localized in microvilli via a Cho-dependent mechanism. Deletion of membrane Cho reduced the levels of γ?ENaC in the apical membrane. Reduced ABCA1 expression and elevated intracellular Cho were observed in old mice, compared to young mice. In parallel, cell-attached patch-clamp data from the split-open cortical collecting ducts (CCD) show that ENaC activity was significantly increased in old mice. These data suggest that elevation of intracellular Cho due to blockade of ABCA1 stimulates ENaC, which may contribute to CsA-induced hypertension. This study also implies that reduced ABCA1 expression may mediate age-related hypertension by increasing ENaC activity via elevation of intracellular Cho.     

Effectiveness of web-based personalised e‑Coaching lifestyle interventions

Introduction

Interventions to reduce the impact of modifiable risk factors, such as hypercholesterolaemia, smoking, and overweight, have the potential to significantly decrease the cardiovascular disease burden. The majority of the global population is unaware of their own risk of developing cardiovascular disease. Parallel to the lack of awareness, a rise in obesity and diabetes is observed. e‑Health tools for lifestyle improvement have shown to be effective in changing unhealthy behaviour. In this study we report on the results of three different trials assessing the effectiveness of MyCLIC, an e‑Coaching lifestyle intervention tool.

Methods

From 2008 to 2016 we conducted three trials: 1) HAPPY NL: a prospective cohort study in the Netherlands, 2) HAPPY AZM: a prospective cohort study with employees of Maastricht UMC+ and 3) HAPPY LONDON: a single-centre, randomised controlled trial with asymptomatic individuals who have a high 10-year CVD risk.

Results

HAPPY NL and HAPPY AZM showed that e‑Coaching reduced cardiovascular risk. Both prospective trials showed a 20–25% relative reduction in 10-year cardiovascular disease risk. A lesser effect was seen in the HAPPY LONDON trial. A low frequency of logins suggests a low degree of content engagement in the e‑Coaching group, which could be age related as the mean age of the participants in the HAPPY LONDON study was high.

Conclusion

e-Coaching using MyCLIC is a low cost and effective method to perform lifestyle interventions and has the potential to reduce the 10-year cardiovascular disease risk.

     

CircSLC39A8 attenuates paclitaxel resistance in ovarian cancer by regulating the miR‑185‑5p/BMF axis

Chemoresistance to paclitaxel (PTX) is one of the main reasons for treatment failure and poor prognosis in patients with advanced ovarian cancer. Therefore, it is imperative to explore the mechanisms related to chemotherapy resistance in ovarian cancer to find potential therapeutic targets. Circular RNAs (circRNAs) play important roles in cancer development and progression. However, their biological functions and clinical significance in ovarian cancer have not been fully elucidated. Therefore, in this study, we aimed to investigate the function and underlying mechanism of hsa_circ_0002782 (circSLC39A8), identified by circRNA sequencing, in regulating PTX resistance. The effects of circSLC39A8 on PTX resistance was assessed by cell viability, colony formation, flow cytometry assays and an in vivo subcutaneous xenografted tumor mouse model. RNA immunoprecipitation and dual-luciferase reporter assays were performed to verify the interaction between circSLC39A8 and the miR-185–5p/BMF signal axis. We found that circSLC39A8 was downregulated in PTX-resistant ovarian cancer cells and tissues, and its low expression was associated with poor prognosis. Biologically, circSLC39A8 knockdown promoted PTX resistance in vitro and in vivo, while circSLC39A8 overexpression showed the opposite effect. Mechanistically, circSLC39A8, acting as an endogenous sponge for miR-185–5p, could relieve the inhibition of miR-185–5p on the expression of its downstream target, BMF; thus enhancing the sensitivity of ovarian cancer to PTX. Our findings demonstrate that circSLC39A8 can promote PTX sensitivity by regulating the miR-185–5p/BMF axis. This may be a valuable prognostic biomarker and a promising therapeutic target for patients with ovarian cancer.     

Correction to: High‑Throughput MicroRNA and mRNA Sequencing Reveals that MicroRNAs may be Involved in Peroxidase‑Mediated Cold Tolerance in Potato

Plant Molecular Biology Reporter -     

The m6A‑methylase complex and mRNA export

During synthesis, mRNA undergoes a number of modifications such as capping, splicing and polyadenylation. These processes are coupled with the orderly deposition of the TREX complex on the mRNA and subsequent recruitment of the NXF1-P15 heterodimer which stimulates the nuclear export of mature mRNAs. mRNAs also undergo a number of internal modifications, the most common of which is the N⁶?methyladenosine (m⁶A) modification. In this review we discuss the recent evidence of coupling between the m⁶A modification, RNA processing and export.     

半乳糖凝集素‑3对骨关节炎成骨细胞矿化的作用研究

炎症反应以炎症因子为代表,是骨关节炎（osteoarthritis,OA）中软骨下骨发生病变的重要机制。炎症因子半乳糖凝集素?3（galectin?3,Gal?3）会引起软骨下骨OA样变,但机制尚不清楚。利用因膝关节OA行全膝关节置换患者的胫骨平台标本,培养成骨细胞。分别在正常氧和缺氧条件下用Gal?3处理成骨细胞后,检测骨钙素、ERRα和Sirtuin 1的表达情况。同时,给予矿化液培养的成骨细胞以Gal?3处理,28 d后使用茜素红染色检测成骨细胞矿化程度并进行定量分析。结果显示,Gal?3抑制成骨细胞骨钙素的表达,在缺氧条件下诱导ERRα和Sirtuin1的表达,在正常氧条件下Gal?3促进OA成骨细胞的矿化。正常氧条件下,Gal?3可以诱导OA成骨细胞的异常矿化,缺氧条件下Gal?3促进成骨,表明Gal?3在OA成骨细胞的矿化中扮演重要角色。     

Correction to: Application of linked and unlinked co‑transformation to generate triple stack,marker‑free,transgenic white clover (Trifolium repens L.)

Plant Cell, Tissue and Organ Culture (PCTOC) - In the original article, the order of transgene names in the column headings of Table 3 was incorrect. The correct Table 3 is printed below. The error...     

RNA‑seq技术在水生生物生态毒理学中的应用进展

水域是地球环境的重要组成部分,也是最易受污染的生态系统之一。水生态系统中不同营养级别的水生生物可通过摄食、接触等多种途径摄入水体中的污染物。因此,监测水域污染物对水生生物和生态系统的影响,解析污染物对不同水生生物的毒性机制,筛选敏感、有效的生物标志物对生态毒理学研究和环境风险评价具有重要意义。RNA测序（RNA sequencing,RNA?seq）技术因所需样品量少,且不需参考序列,可在整体水平上鉴定基因差异表达,成为水生生物生态毒理学研究的最佳方法之一。基于此,介绍了RNA?seq技术的基本流程与数据分析过程,对该技术在不同生态位的水生生物（如鱼类、两栖类、贝类、甲壳类等）生态毒理学中的应用展开综述,并对RNA?seq技术面临的不足、挑战及发展趋势进行探讨,以期为该技术在水生生物生态毒理学研究中的应用,尤其是水生态环境中污染物胁迫水生生物机制的阐明及污染水域生态环境恢复提供参考。     

A homologous series of apoptosis-inducing N‑acylserinols: Thermotropic phase behavior,interaction with cholesterol and characterization of cationic N‑myristoylserinol-cholesterol-CTAB niosomes

N?Acylserinols (NASOHs) exhibit anti-cancer activity by elevating ceramide levels, and/or by activating proapoptotic effectors. In the present work we investigated the thermotropic phase behavior and supramolecular organization of a homologous series of NASOHs (number of C-atoms in the acyl chain, n?=?8–18), and the interaction of N-myristoylserinol (NMSOH) with cholesterol, and characterized cationic niosomes made up of NMSOH, cholesterol and cetyltrimethylammonium bromide (CTAB). Differential scanning calorimetric studies revealed that NASOHs exhibit a major chain-melting phase transition in both dry and hydrated states. The thermodynamic parameters, transition enthalpy and entropy show linear dependence on the acyl chain length in the dry state, but exhibit odd-even alternation in the hydrated state. Powder X-ray diffraction studies revealed that NASOHs adopt a tilted bilayer structure, wherein the bilayer repeat distances (d-spacings) also showed odd-even alteration, with even-chainlength compounds exhibiting slightly higher d-spacings. Studies on the interaction between NMSOH and cholesterol revealed that both lipids mix well with up to 55?mol% cholesterol, whereas phase separation was observed at higher cholesterol content. The transition enthalpy corresponding to the NMSOH-cholesterol complex increases up to 55?mol% cholesterol and decreases at higher cholesterol content. Presence of the cationic surfactant CTAB affects the phase behavior, fluidity and size of the NMSOH-cholesterol (45,55, mol/mol) niosomes, with unilamellar vesicles of about 85 (±20) nm in diameter being obtained at 10?mol% CTAB. These results provide a thermodynamic and structural basis for further investigations on these cationic niosomes towards their use in drug delivery applications, especially for anticancer drugs.     

Heart teams in the Netherlands: From teamwork to data‑driven decision-making

For all patients with cardiovascular disease requiring an intervention, this is a major life event. The heart team concept is one of the most exciting and effective team modalities to ensure cost-effective application of invasive cardiovascular care. It optimises patient selection in a complex decision-making process and identifies risk/benefit ratios of different interventions. Informed consent and patient safety should be at the centre of these decisions. To deal with increased load of medical data in the future, artificial intelligence could enable objective and effective interpretation of medical imaging and decision support. This technical support is indispensable to meet current patient and societal demands for informed consent, shared decision-making, outcome improvement and safety. The heart team should be restructured with clear leadership, accountability, and process and outcome measurement of interventions. In this way, the heart team concept in the Netherlands will be ready for the future.

     

Structure-dynamic and functional relationships in a Li+-transporting sodium‑calcium exchanger mutant

The cell membrane (NCX) and mitochondrial (NCLX) Na⁺/Ca²⁺ exchangers control Ca²⁺ homeostasis. Eleven (out of twelve) ion-coordinating residues are highly conserved among eukaryotic and prokaryotic NCXs, whereas in NCLX, nine (out of twelve) ion-coordinating residues are different. Consequently, NCXs exhibit high selectivity for Na⁺ and Ca²⁺, whereas NCLX can exchange Ca²⁺ with either Na⁺ or Li⁺. However, the underlying molecular mechanisms and physiological relevance remain unresolved. Here, we analyzed the NCX_Mj-derived mutant NCLX_Mj (with nine substituted residues) imitating the ion selectivity of NCLX. Site-directed fluorescent labeling and ion flux assays revealed the nearly symmetric accessibility of ions to the extracellular and cytosolic vestibules in NCLX_Mj (K_int?=?0.8–1.4), whereas the extracellular vestibule is predominantly accessible to ions (K_int?=?0.1–0.2) in NCX_Mj. HDX-MS (hydrogen-deuterium exchange mass-spectrometry) identified symmetrically rigidified core helix segments in NCLX_Mj, whereas the matching structural elements are asymmetrically rigidified in NCX_Mj. The HDX-MS analyses of ion-induced conformational changes and the mutational effects on ion fluxes revealed that the “Ca²⁺-site” (S_Ca) of NCLX_Mj binds Na⁺, Li⁺, or Ca²⁺, whereas one or more additional Na⁺/Li⁺ sites of NCLX_Mj are incompatible with the Na⁺ sites (S_ext and S_int) of NCX_Mj. Thus, the replacement of ion-coordinating residues in NCLX_Mj alters not only the ion selectivity of NCLX_Mj, but also the capacity and affinity for Na⁺/Li⁺ (but not for Ca²⁺) binding, bidirectional ion-accessibility, the response of the ion-exchange to membrane potential changes, and more. These structure-controlled functional features could be relevant for differential contributions of NCX and NCLX to Ca²⁺ homeostasis in distinct sub-cellular compartments.     

Erythrocyte heme‑oxygenation status indicated as a risk factor in prehypertension by Raman spectroscopy

Raman spectroscopy of erythrocytes provides detailed information about the structure and status of heme moiety, which can be used to provide new insights into molecular pathogenesis of several diseases. In this study, we present the first Raman spectroscopy investigations of the effect of hemoglobin oxygenation in the context of hypertensive disease. The experimental data was subjected to Logistic Regression, which indicated heme?oxygenation status as an important risk factor alongside other clinical parameters. The 1605/1621?cm^?1 band ratio was selected as an optimal Raman metric for risk assessment and along with other band ratios (1583, 1639, 1310?cm^?1) related to heme status and when combined with clinical data via logistic regression gave an Area Under the Curve (AUC) >0.95 for prehypertension risk prediction. The work demonstrates the feasibility of Raman spectroscopy to distinguish between prehypertensive and normotensive states. Simultaneously, it is implied that the etiology of the high blood pressure progression may be connected with the changes in hemoglobin oxygenation.     

Device updates successfully reduce T‑wave oversensing and inappropriate shocks in subcutaneous ICD patients

Aims

To analyse the impact of device and software updates on the prevention of T?wave oversensing (TWOS) and inappropriate shocks (IS) in subcutaneous ICD (S-ICD) patients.

Background

TWOS is a feared complication after implantation. It may lead to harmful IS. To date, specific strategies to reduce these events are lacking.

Methods

In this retrospective single-centre trial we analysed 146 S?ICD patients who were implanted between 2010 and 2016. In all eligible consecutive patients (n?=?139), follow-up of at least 6 weeks was studied. The incidence of TWOS/IS was analysed in patients receiving a 2^nd generation S?ICD (Emblem-S-ICD) between 2014 and 2016 (Emblem). Their outcome was compared with a control group (SQ) treated with the SQ1010 device between 2010 and 2014, who were followed up for a maximum of 2 years. Furthermore, to test if the software update SMR8 reduces inappropriate shocks in the SQ1010-S-ICD population, the incidence of TWOS/IS was evaluated before and after update installation.

Results

Basic characteristics and indications for S?ICD implantation were similar in both groups. However, the cumulative incidence of TWOS/IS was significantly decreased in Emblem vs. SQ (SQ: 15.4%, n?=?14/91 vs. Emblem 4.2%, n?=?2/48; p?=?0.049). Furthermore, with regards to the SQ population we also observed a trend towards a significant reduction of TWOS/IS after installation of the software update SMR8 in 2014 (before update: 13.4%, n?=?11/82 vs. after update: 4.6%, 3/65, p?=?0.07).

Conclusion

2^nd generation devices but probably also the SMR8 software update reduce the incidence of TWOS/IS in S?ICD patients.

     

A 5‑lipoxygenase-specific sequence motif impedes enzyme activity and confers dependence on a partner protein

Leukotrienes (LT) are lipid mediators of the inflammatory response that play key roles in diseases such as asthma and atherosclerosis. The precursor leukotriene A₄ (LTA₄) is synthesized from arachidonic acid (AA) by 5‑lipoxygenase (5-LOX), a membrane-associated enzyme, with the help of 5‑lipoxygenase-activating protein (FLAP), a nuclear transmembrane protein. In lipoxygenases the main chain carboxylate of the C-terminus is a ligand for the non-heme iron and thus part of the catalytic center. We investigated the role of a lysine-rich sequence (KKK^653–655) 20 amino acids upstream of the C-terminus unique to 5-LOX that might displace the main-chain carboxylate in the iron coordination sphere. A 5-LOX mutant in which KKK^653–655 is replaced by ENL was transfected into HEK293 cells in the absence and presence of FLAP. This mutant gave ~20-fold higher 5-LOX product levels in stimulated HEK cells relative to the wild-type 5-LOX. Co-expression of the enzymes with FLAP led to an equalization of 5-LOX products detected, with wild-type 5-LOX product levels increased and those from the mutant enzyme decreased. These data suggest that the KKK motif limits 5-LOX activity and that this attenuated activity must be compensated by the presence of FLAP as a partner protein for effective LT biosynthesis.     

Criminal Prohibition of Wrongful Re‑identification: Legal Solution or Minefield for Big Data?

The collapse of confidence in anonymization (sometimes also known as de-identification) as a robust approach for preserving the privacy of personal data has incited an outpouring of new approaches that aim to fill the resulting trifecta of technical, organizational, and regulatory privacy gaps left in its wake. In the latter category, and in large part due to the growth of Big Data–driven biomedical research, falls a growing chorus of calls for criminal and penal offences to sanction wrongful re-identification of “anonymized” data. This chorus cuts across the fault lines of polarized privacy law scholarship that at times seems to advocate privacy protection at the expense of Big Data research or vice versa. Focusing on Big Data in the context of biomedicine, this article surveys the approaches that criminal or penal law might take toward wrongful re-identification of health data. It contextualizes the strategies within their respective legal regimes as well as in relation to emerging privacy debates focusing on personal data use and data linkage and assesses the relative merit of criminalization. We conclude that this approach suffers from several flaws and that alternative social and legal strategies to deter wrongful re-identification may be preferable.     

Early experience with the Venus p‑valve for percutaneous pulmonary valve implantation in native outflow tract

Introduction

The Venus p?valve (MedTech, Shanghai, China) is a self-expanding percutaneous heart valve designed to be implanted in a native patched right ventricle outflow tract. The worldwide clinical experience with this valve is just beginning and the results have so far been encouraging. We present our initial early experience implanting the Venus p?valve in the native right ventricle outflow tract of patients with Tetralogy of Fallot repaired with a transannular patch.

Methods

In 10 selected patients a procedure for percutaneous pulmonary valve implantation was performed using the Venus p?valve. The patients mean age was 32 years (13–57), mean weight 59.6?kg (40–80). All patients had Tetralogy of Fallot with moderate to severe pulmonary regurgitation and an indication for pulmonary valve replacement.

Results

The implantation procedure was successful in all the patients resulting in an immediately functional valve. No procedure-related complications were observed. Follow-up after 12 months (4–21) resulted in an improvement in NYHA class. There was a reduction of the mean right ventricle diastolic volume from 139?ml/m² (105–179) to 78?ml/m² (65–100) and improvement in the regurgitation fraction from 42% (29–58) to 1% (0–5), as seen on routine cardiac magnetic resonance 6 months after the implantation. No stent fractures have been observed so far.

Conclusion

Percutaneous pulmonary valve implantation with the Venus p?valve resulted in a safe and effective procedure. The valve has predictable and sustained functional competence, resulting in clinical improvement in the patients.

     

Correction to: CIN‑like TCP13 is essential for plant growth regulation under dehydration stress

Plant Molecular Biology -     

LncRNA GABPB1‑IT1 inhibits the tumorigenesis of renal cancer via the miR-21/PTEN axis

Long noncoding RNA (lncRNA) (GABPB1‑IT1) has been reported to be downregulated in lung cancer, while its expression and function in other cancers are unknown. In this study, the expression levels of GABPB1‑IT1 in tissue samples from 62 ccRCC patients were measured by performing RT-qPCR. Potential base pairing formed between GABPB1‑IT1 and miR-21 was explored using the online program IntaRNA 2.0 and further confirmed by Dual-luciferase activity assay and RNA pulldown assay. The role of GABPB1‑IT1 and miR-21 in regulating the expression of PTEN was evaluated by RT-qPCR and Western blot. The role of GABPB1‑IT1, miR-21, and PTEN in regulating the proliferation of Caki-2 cells was explored by CCK-8 assay. It was observed that GABPB1‑IT1 was downregulated in ccRCC and predicted poor survival. GABPB1‑IT1 directly interacted with miR-21, while it did not regulate the expression of each other. Moreover, upregulation of PTEN, which is a target of miR-21, was observed in ccRCC cells with overexpression of GABPB1‑IT1. Overexpression of GABPB1‑IT1 and PTEN decreased the proliferation rates of ccRCC cells. In addition, overexpression of GABPB1‑IT1 reduced the enhancing effects of miR-21 on cell proliferation. Therefore, GABPB1‑IT1 may upregulate PTEN by sponging miR-21 in ccRCC to inhibit cancer cell proliferation. Our study characterized a novel GABPB1‑IT1/miR-21/PTEN axis in ccRCC.