Twist to Boost: Circumventing Quantum Yield and Dissymmetry Factor Trade-Off in Circularly Polarized Luminescence.

Circularly polarized luminescence (CPL) enables promising applications in asymmetric photonics. However, the performances of CPL molecules do not yet meet the requirements of these applications. The shortcoming originates from the trade-off in CPL between the photoluminescence quantum yield (PLQY) and the photoluminescence dissymmetry factor (gPL). In this study, we developed a molecular strategy to circumvent this trade-off. Our approach takes advantage of the strong propensity of [Pt(N^C^N)Cl], where the N^C^N ligand is 1-(2-oxazoline)-3-(2-pyridyl)phenylate, to form face-to-face stacks. We introduced chiral substituents, including (S)-methyl, (R)- and (S)-isopropyl, and (S)-indanyl groups, into the ligand framework. This asymmetric control induces torsional displacements that give homohelical stacks of the Pt(II) complexes. X-ray single-crystal structure analyses for the (S)-isopropyl Pt(II) complex reveal the formation of a homohelical dimer with a Pt···Pt distance of 3.48 Å, which is less than the sum of the van der Waals radii of Pt. This helical stack elicits the metal-metal-to-ligand charge-transfer (MMLCT) transition that exhibits strong chiroptical activity due to the electric transition moment making an acute angle to the magnetic transition moment. The PLQY and gPL values of the MMLCT phosphorescence emission of the (S)-isopropyl Pt(II) complex are 0.49 and 8.4 × 10-4, which are improved by factors of ca. 6 and 4, respectively, relative to the values of the unimolecular emission (PLQY, 0.078; gPL, 2.4 × 10-4). Our photophysical measurements for the systematically controlled Pt(II) complexes reveal that the CPL amplifications depend on the chiral substituent. Our investigations also indicate that excimers are not responsible for the enhanced chiroptical activity. To demonstrate the effectiveness of our approach, organic electroluminescence devices were fabricated. The MMLCT emission devices were found to exhibit simultaneous enhancements in the external quantum efficiency (EQE, 9.7%) and the electroluminescence dissymmetry factor (gEL, 1.2 × 10-4) over the unimolecular emission devices (EQE, 5.8%; gEL, 0.3 × 10-4). These results demonstrate the usefulness of using the chiroptically active MMLCT emission for achieving an amplified CPL.

A Dansyl-Modified Sphingosine Kinase Inhibitor DPF-543 Enhanced De Novo Ceramide Generation.

Sphingosine-1-phosphate (S1P) synthesized by sphingosine kinase (SPHK) is a signaling molecule, involved in cell proliferation, growth, differentiation, and survival. Indeed, a sharp increase of S1P is linked to a pathological outcome with inflammation, cancer metastasis, or angiogenesis, etc. In this regard, SPHK/S1P axis regulation has been a specific issue in the anticancer strategy to turn accumulated sphingosine (SPN) into cytotoxic ceramides (Cers). For these purposes, there have been numerous chemicals synthesized for SPHK inhibition. In this study, we investigated the comparative efficiency of dansylated PF-543 (DPF-543) on the Cers synthesis along with PF-543. DPF-543 deserved attention in strong cytotoxicity, due to the cytotoxic Cers accumulation by ceramide synthase (CerSs). DPF-543 exhibited dual actions on Cers synthesis by enhancing serine palmitoyltransferase (SPT) activity, and by inhibiting SPHKs, which eventually induced an unusual environment with a high amount of 3-ketosphinganine and sphinganine (SPA). SPA in turn was consumed to synthesize Cers via de novo pathway. Interestingly, PF-543 increased only the SPN level, but not for SPA. In addition, DPF-543 mildly activates acid sphingomyelinase (aSMase), which contributes a partial increase in Cers. Collectively, a dansyl-modified DPF-543 relatively enhanced Cers accumulation via de novo pathway which was not observed in PF-543. Our results demonstrated that the structural modification on SPHK inhibitors is still an attractive anticancer strategy by regulating sphingolipid metabolism.

A Bioassay Using a Pentadecanal Derivative to Measure S1P Lyase Activity.

Sphingosine-1-phosphate (S1P) is a unique lipid ligand binding to S1P receptors to transduce various cell survival or proliferation signals via small G proteins. S1P lyase (S1PL) is the specific enzyme that degrades S1P to phosphoethanolamine and (2E)-hexadecenal and therefore regulates S1P levels. S1PL also degrades dihydrosphingosine-1-phosphate (Sa1P), with a higher affinity to produce hexadecanal. Here, we developed a newly designed assay using a C17-Sa1P substrate that degrades into pentadecanal and phosphoethanolamine. For higher sensitivity in pentadecanal analysis, we developed a quantitative protocol as well as a 5,5-dimethyl cyclohexanedione (5,5-dimethyl CHD) derivatization method. The derivatization conditions were optimized for the reaction time, temperature, and concentrations of the 5,5-dimethyl CHD reagent, acetic acid, and ammonium acetate. The S1PL reaction in the cell lysate after spiking 20 µM of C17-Sa1P for 20 min was linear to the total protein concentrations of 50 µg. The S1PL levels (4 pmol/mg/min) were readily detected in this HPLC with fluorescence detection (λex = 366 nm, λem = 455 nm). The S1PL-catalyzed reaction was linear over 30 min and yielded a Km value of 2.68 µM for C17-Sa1P. This new method was validated to measure the S1PL activity of mouse embryonal carcinoma cell lines of the standard cell (F9-0), S1PL knockdown cells (F9-2), and S1PL-overexpressed cells (F9-4). Furthermore, we treated F9-4 cells with different S1PL inhibitors such as FTY720, 4-deoxypyridoxine (DOP), and the deletion of pyridoxal-5-phosphate (P5P), an essential cofactor for S1PL activity, and observed a significant decrease in pentadecanal relative to the untreated cells. In conclusion, we developed a highly sensitive S1PL assay using a C17-Sa1P substrate for pentadecanal quantification for application in the characterization of S1PL activity in vitro.

Activation of Hair Cell Growth Factors by Linoleic Acid in Malva verticillata Seed.

Hair loss by excessive stress from work and lifestyle changes has become a growing concern, particularly among young individuals. However, most drugs for alopecia impose a plethora of side effects. We have found the powerful impact of Malva verticillata seed extracts on alleviating hair loss. This study further isolated effective chemicals in M. verticillata seed extracts by liquid silica gel column chromatography. Under the screening for the growth rate (%) of human follicles dermal papilla cells (HFDPCs), we identified linoleic acid (LA) and oleic acid in n-hexane of M. verticillate (MH)2 fraction. LA treatment activated Wnt/ß-catenin signaling and induced HFDPCs growth by increasing the expression of cell cycle proteins such as cyclin D1 and cyclin-dependent kinase 2. LA treatment also increased several growth factors, such as vascular endothelial growth factor, insulin-like growth factor-1, hepatocyte growth factor, and keratinocyte growth factor, in a dose-dependent manner. Besides, LA significantly inhibited Dickkopf-related protein expression (DKK-1), a primary alopecia signaling by dihydrotestosterone. Our findings suggest that LA treatment may alleviate a testosterone-induced signaling molecule and induces HFDPCs growth by activating Wnt/ß-catenin signaling.

Differential expressions of L1-chimeric transcripts in normal and matched-cancer tissues.

L1s are a cis-regulatory elements and contain bidirectional internal promoters within the 5' untranslated region (UTR). L1s provide bidirectional promoters that generate alternative transcripts and affect differential expressions in the human genome. In particular, L1 antisense promoters (L1ASPs) could produce aberrant transcripts in cancer tissues compared to normal tissues. In this study, we identified the L1-chimeric transcripts derived from L1ASPs and analyzed relative expression of L1-chimeric transcripts between normal and matched-cancer tissues. First, we collected 425 L1-chimeric transcripts by referring to previous studies. Through the manual inspection, we identified 144 L1-chimeric transcripts derived from 44 L1 antisense promoters, suggesting that the antisense promoter acted as an alternative promoter. We analyzed relative gene expression levels of 16 L1-chimeric transcripts between matched cancer-normal tissue pair (lung, liver, gastric, kidney, thyroid, breast, ovary, uterus, and prostate) using real-time quantitative PCR (RT-qPCR) and investigated putative transcription factor binding motifs to determine activity of L1ASPs. Taken together, we propose that L1ASPs could contribute to the differential gene expression between normal and cancer tissues.

Predicting Carcinogenic Mechanisms of Non-Genotoxic Carcinogens via Combined Analysis of Global DNA Methylation and In Vitro Cell Transformation.

An in vitro cell transformation assay (CTA) is useful for the detection of non-genotoxic carcinogens (NGTXCs); however, it does not provide information on their modes of action. In this study, to pursue a mechanism-based approach in the risk assessment of NGTXCs, we aimed to develop an integrated strategy comprising an in vitro Bhas 42 CTA and global DNA methylation analysis. For this purpose, 10 NGTXCs, which were also predicted to be negative through Derek/Sarah structure-activity relationship analysis, were first tested for transforming activity in Bhas 42 cells. Methylation profiles using reduced representation bisulfite sequencing were generated for seven NGTXCs that were positive in CTAs. In general, the differentially methylated regions (DMRs) within promoter regions showed slightly more bias toward hypermethylation than the DMRs across the whole genome. We also identified 13 genes associated with overlapping DMRs within the promoter regions in four NGTXCs, of which seven were hypermethylated and six were hypomethylated. Using ingenuity pathway analysis, the genes with DMRs at the CpG sites were found to be enriched in cancer-related categories, including "cell-to-cell signaling and interaction" as well as "cell death and survival". Moreover, the networks related to "cell death and survival", which were considered to be associated with carcinogenesis, were identified in six NGTXCs. These results suggest that epigenetic changes supporting cell transformation processes occur during non-genotoxic carcinogenesis. Taken together, our combined system can become an attractive component for an integrated approach for the testing and assessment of NGTXCs.

Cellular and Metabolic Basis for the Ichthyotic Phenotype in NIPAL4 (Ichthyin)-Deficient Canines.

Mutations in several lipid synthetic enzymes that block fatty acid and ceramide production produce autosomal recessive congenital ichthyoses (ARCIs) and associated abnormalities in permeability barrier homeostasis. However, the basis for the phenotype in patients with NIPAL4 (ichthyin) mutations (among the most prevalent ARCIs) remains unknown. Barrier function was abnormal in an index patient and in canines with homozygous NIPAL4 mutations, attributable to extensive membrane stripping, likely from detergent effects of nonesterified free fatty acid. Cytotoxicity compromised not only lamellar body secretion but also formation of the corneocyte lipid envelope (CLE) and attenuation of the cornified envelope (CE), consistent with a previously unrecognized, scaffold function of the CLE. Together, these abnormalities result in failure to form normal lamellar bilayers, accounting for the permeability barrier abnormality and clinical phenotype in NIPA-like domain-containing 4 (NIPAL4) deficiency. Thus, NIPAL4 deficiency represents another lipid synthetic ARCI that converges on the CLE (and CE), compromising their putative scaffold function. However, the clinical phenotype only partially improved after normalization of CLE and CE structure with topical ω-O-acylceramide because of ongoing accumulation of toxic metabolites, further evidence that proximal, cytotoxic metabolites contribute to disease pathogenesis.

Anti-inflammatory effect of a novel synthetic compound 1-((4-fluorophenyl)thio)isoquinoline in RAW264.7 macrophages and a zebrafish model.

The compound, 1-((4-fluorophenyl)thio)isoquinoline (FPTQ), is a synthetic isoquinoline derivative. To test the anti-inflammatory effect of FPTQ, we used neutrophil-specific transgenic zebrafish Tg(mpx::EGFP)i114 line and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. We also used two different methods, involving tail transection and LPS stimulation in the zebrafish model. Neutrophils translocation in the zebrafish tail-transected model was inhibited by FPTQ. Neutrophil aggregation was also inhibited by FPTQ in the LPS-stimulated zebrafish model. Decreased mRNA expression of the pro-inflammatory cytokine genes, interleukin-1ß (il-1ß) and interleukin-6 (il-6), was found in zebrafish larvae injected with FPTQ. Additionally, production of nitric oxide was inhibited by FPTQ in RAW264.7 macrophage cells treated with LPS. Moreover, the mRNA expression of Il-1ß and Il-6 suppressed by FPTQ treatment in RAW264.7 macrophage cells, and an enzyme immunoassay showed that FPTQ suppressed the secretion of IL-1ß and IL-6 in RAW264.7 cells. These results demonstrate that FPTQ reduced inflammatory responses and, therefore, suggest that it may be effective as an anti-inflammatory agent.

ER stress stimulates production of the key antimicrobial peptide, cathelicidin, by forming a previously unidentified intracellular S1P signaling complex.

We recently identified a previously unidentified sphingosine-1-phosphate (S1P) signaling mechanism that stimulates production of a key innate immune element, cathelicidin antimicrobial peptide (CAMP), in mammalian cells exposed to external perturbations, such as UVB irradiation and other oxidative stressors that provoke subapoptotic levels of endoplasmic reticulum (ER) stress, independent of the well-known vitamin D receptor-dependent mechanism. ER stress increases cellular ceramide and one of its distal metabolites, S1P, which activates NF-κB followed by C/EBPα activation, leading to CAMP production, but in a S1P receptor-independent fashion. We now show that S1P activates NF-κB through formation of a previously unidentified signaling complex, consisting of S1P, TRAF2, and RIP1 that further associates with three stress-responsive proteins; i.e., heat shock proteins (GRP94 and HSP90α) and IRE1α. S1P specifically interacts with the N-terminal domain of heat shock proteins. Because this ER stress-initiated mechanism is operative in both epithelial cells and macrophages, it appears to be a universal, highly conserved response, broadly protective against diverse external perturbations that lead to increased ER stress. Finally, these studies further illuminate how ER stress and S1P orchestrate critical stress-specific signals that regulate production of one protective response by stimulating production of the key innate immune element, CAMP.

Ethylene Epoxidation Catalyzed by Ag Nanoparticles on Ag-LSX Zeolites formed by Pressure- and Temperature-Induced Auto-Reduction.

Ag+ -Exchanged LSX (Ag-LSX: Ag96 Al96 Si96 O384 ⋅n H2 O), a large pore low silica analogue (Si/Al=1.0) of faujasite, was prepared and post-synthetically modified using pressure and temperature in the presence of various pore-penetrating fluids. Using high-resolution synchrotron X-ray powder and single crystal diffraction we derive structural models of the as-prepared and post-synthetically modified Ag-LSX materials. In the as-prepared Ag-LSX model, we located 96 silver cations and 245 H2 O molecules distributed over seven and five distinctive sites, respectively. At 1.4(1) GPa pressure and 150 °C in ethanol the number of silver cations within the pores of Ag-LSX is reduced by ca. 47.4 %, whereas the number of H2 O molecules is increased by ca. 40.8 %. The formation of zero-valent silver nanoparticles deposited on Ag-LSX crystallites depends on the fluid present during pressurization. Ag-nanoparticle-Ag-zeolite hybrid materials are recovered after pressure release and shown to have different chemical reactivity when used as catalysts for ethylene epoxidation.

Ablation of ceramide synthase 2 exacerbates dextran sodium sulphate-induced colitis in mice due to increased intestinal permeability.

Ceramides mediate crucial cellular processes including cell death and inflammation and have recently been implicated in inflammatory bowel disease. Ceramides consist of a sphingoid long-chain base to which fatty acids of various length can be attached. We now investigate the effect of alerting the ceramide acyl chain length on a mouse model of colitis. Ceramide synthase (CerS) 2 null mice, which lack very-long acyl chain ceramides with concomitant increase of long chain bases and C16-ceramides, were more susceptible to dextran sodium sulphate-induced colitis, and their survival rate was markedly decreased compared with that of wild-type littermates. Using mixed bone-marrow chimeric mice, we showed that the host environment is primarily responsible for intestinal barrier dysfunction and increased intestinal permeability. In the colon of CerS2 null mice, the expression of junctional adhesion molecule-A was markedly decreased and the phosphorylation of myosin light chain 2 was increased. In vitro experiments using Caco-2 cells also confirmed an important role of CerS2 in maintaining epithelial barrier function; CerS2-knockdown via CRISPR-Cas9 technology impaired barrier function. In vivo myriocin administration, which normalized long-chain bases and C16-ceramides of the colon of CerS2 null mice, increased intestinal permeability as measured by serum FITC-dextran levels, indicating that altered SLs including deficiency of very-long-chain ceramides are critical for epithelial barrier function. In conclusion, deficiency of CerS2 influences intestinal barrier function and the severity of experimental colitis and may represent a potential mechanism for inflammatory bowel disease pathogenesis.

Anti-inflammatory mechanism of exogenous C2 ceramide in lipopolysaccharide-stimulated microglia.

Ceramide is a major molecule among the sphingolipid metabolites which are produced in the brain and other organs and act as intracellular second messengers. Although a variety of physiological roles of ceramide have been reported in the periphery and central nervous systems, the role of ceramide in microglial activation has not been clearly demonstrated. In the present study, we examined the effects of exogenous cell permeable short chain ceramides on microglial activation in vitro and in vivo. We found that C2, C6, and C8 ceramide and C8 ceramide-1-phosphate inhibited iNOS and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated BV2 microglial cells and rat primary microglia. In addition, the administration of C2 ceramide suppressed microglial activation in the brains of LPS-exposed mice. By HPLC and LC/MS/MS analyses, we found that C2 ceramide on its own, rather than its modified form (i.e. ceramide-1-phosphate or long chain ceramides), mainly work by penetrating into microglial cells. Further mechanistic studies by using the most effective C2 ceramide among the short chain ceramides tested, revealed that C2 ceramide exerts anti-inflammatory effects via inhibition of the ROS, MAPKs, PI3K/Akt, and Jak/STAT pathways with upregulation of PKA and hemeoxygenase-1 expressions. Interestingly, we found that C2 ceramide inhibits TLR4 signaling by interfering with LPS and TLR4 interactions. Therefore, our data collectively suggests the therapeutic potential of short chain ceramides such as C2 for neuroinflammatory disorders such as Alzheimer's disease and Parkinson's disease.

Quantification of recombinant human erythropoietin by amino acid analysis using isotope dilution liquid chromatography-tandem mass spectrometry.

Herein, we describe an accurate method for protein quantification based on conventional acid hydrolysis and an isotope dilution-ultra performance liquid chromatography-tandem mass spectrometry method. The analyte protein, recombinant human erythropoietin (rhEPO), was effectively hydrolyzed by incubation with 8 mol/L hydrochloric acid at 130 °C for 48 h, in which at least 1 µmol/kg of rhEPO was treated to avoid possible degradation of released amino acids during hydrolysis. Prior to hydrolysis, sample solution was subjected to ultrafiltration to eliminate potential interfering substances. In a reversed-phase column, the analytes (phenylalanine, proline, and valine) were separated within 3 min using gradient elution comprising 20 % (v/v) acetonitrile and 10 mmol/L ammonium acetate, both containing 0.3 % (v/v) trifluoroacetic acid. The optimized hydrolysis and analytical conditions in our study were strictly validated in terms of accuracy and precision, and were suitable for the accurate quantification of rhEPO. Certified rhEPO was analyzed using a conventional biochemical assay kit as an additional working calibrant for the quantification of EPO and improved the accuracy. The optimized protocol is suitable for the accurate quantification of rhEPO and satisfactorily serves as a reference analytical procedure for the certification of rhEPO and similar proteins.

Determination of a novel diacylglycerol acyltransferase 1 inhibitor, 2-[4-(4-{5-[2-phenyl-5-(trifluoromethyl) oxazole-4-carboxamido]-1H-benzo[d]imidazol-2-yl} phenyl) cyclohexyl] acetic acid (KR-69232) in rat plasma using liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

A liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of KR-69232, a diacyltransferase 1 inhibitor, in rat plasma. KR-69232 in the concentration range of 0.004-4 µg/mL was linear. The intra-and inter-day precision and accuracy were acceptable (<20%). KR-69232 was stable under various storage and handling conditions. The method was applied successfully in a pharmacokinetic study of KR-69232 in rats.

Localized thymic amyloidosis presenting with myasthenia gravis: case report.

A mediastinal mass was incidentally found on chest radiography in a 46-yr-old woman who had had myasthenia gravis (MG) for 2 months. Computed tomography revealed a 4-cm in size, well-defined, and lobulating mass with nodular calcification that was located in the thymus. Microscopically, the mass consisted of diffuse amorphous eosinophilic materials. These deposits exhibited apple-green birefringence under polarized light microscopy after Congo red staining. Immunohistochemical analysis revealed that they were positive for both kappa and lambda light chains and negative for amyloid A. A diagnosis of localized primary thymic amyloidosis was finally made. After thymectomy, the symptoms of MG were controlled with reduced corticosteroid requirements. Localized thymic amyloidosis associated with MG has not been reported to date.

Development of a sensitive LC-MS/MS method for determination of N-nitrosopiperazine in levocetirizine.

Levocetirizine is one of the widely used antihistamines and has the potential to form N-nitrosopiperazine (NPZ) during drug synthesis, manufacturing, or storage. NPZ classified as a nitrosamine is a genotoxic impurity with carcinogenic properties. Controlling the presence of NPZ in the active pharmaceutical ingredient (API) and drug products is crucial with levels ideally maintained below 80 ppm. Herein, we developed a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique to analyze NPZ levels in levocetirizine API and various formulations. Chromatographic separation was carried out using an F5 column with mobile phases consisting of 2 mM ammonium formate in water and acetonitrile, employing gradient elution mode at a flow rate of 0.2 mL min-1. The column oven temperature was set at 30 °C, and the injection volume was 2 µL. NPZ quantification was achieved using positive electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The developed method underwent rigorous validation according to regulatory guidelines. The limit of quantification (LOQ) was established at 1 ng mL-1 within the range of 1-50 ng mL-1, covering 10-500% of the specified NPZ limit in drugs. The effectiveness of the method was shown by utilizing it to analyze the NPZ impurity in both levocetirizine API and various drug products, including tablets, capsules, chewables, and syrups. The proposed method and the resulting data would be valuable for determining potentially present impurities in drug substances or products for quality assessment.

Eco-friendly natural mineral biotite as a cesium adsorbent: Utilizing low-concentration acid and hydrogen peroxide.

Biotite, a phyllosilicate mineral, possesses significant potential for cesium (Cs) adsorption owing to its negative surface charge, specific surface area (SSA), and frayed edge sites (FES). Notably, FES are known to play an important role in the adsorption of Cs. The objectives of this study were to investigate the Cs adsorption capacity and behavior of artificially weathered biotite and identify mineralogical characteristics for the development of an eco-friendly geologically-based Cs adsorbent. Through various analyses, it was confirmed that the FES of biotite was mainly formed by mineral structural distortion during artificial weathering. The Cs adsorption capacity is improved by approximately 39% (from 20.53 to 28.63 mg g-1) when FES are formed in biotite through artificial weathering using a low-concentration acidic solution mixed with hydrogen peroxide (H2O2). Especially, the Cs selectivity in Cs-containing seawater, including high concentrations of cations and organic matter, was significantly enhanced from 203.2 to 1707.6 mL g-1, an increase in removal efficiency from 49.5 to 89.2%. These results indicate that FES of artificially weathered biotite play an essential role in Cs adsorption. Therefore, this simple and economical weathering method, which uses a low-concentration acidic solution mixed with H2O2, can be applied to natural minerals for use as Cs adsorbents.

Histopathologic image-based deep learning classifier for predicting platinum-based treatment responses in high-grade serous ovarian cancer.

Platinum-based chemotherapy is the cornerstone treatment for female high-grade serous ovarian carcinoma (HGSOC), but choosing an appropriate treatment for patients hinges on their responsiveness to it. Currently, no available biomarkers can promptly predict responses to platinum-based treatment. Therefore, we developed the Pathologic Risk Classifier for HGSOC (PathoRiCH), a histopathologic image-based classifier. PathoRiCH was trained on an in-house cohort (n = 394) and validated on two independent external cohorts (n = 284 and n = 136). The PathoRiCH-predicted favorable and poor response groups show significantly different platinum-free intervals in all three cohorts. Combining PathoRiCH with molecular biomarkers provides an even more powerful tool for the risk stratification of patients. The decisions of PathoRiCH are explained through visualization and a transcriptomic analysis, which bolster the reliability of our model's decisions. PathoRiCH exhibits better predictive performance than current molecular biomarkers. PathoRiCH will provide a solid foundation for developing an innovative tool to transform the current diagnostic pipeline for HGSOC.

Cardiomyocyte specific deficiency of serine palmitoyltransferase subunit 2 reduces ceramide but leads to cardiac dysfunction.

The role of serine palmitoyltransferase (SPT) and de novo ceramide biosynthesis in cardiac ceramide and sphingomyelin metabolism is unclear. To determine whether the de novo synthetic pathways, rather than ceramide uptake from circulating lipoproteins, is important for heart ceramide levels, we created cardiomyocyte-specific deficiency of Sptlc2, a subunit of SPT. Heart-specific Sptlc2-deficient (hSptlc2 KO) mice had a >35% reduction in ceramide, which was limited to C18:0 and very long chain ceramides. Sphingomyelinase expression, and levels of sphingomyelin and diacylglycerol were unchanged. But surprisingly phospholipids and acyl CoAs contained increased saturated long chain fatty acids. hSptlc2 KO mice had decreased fractional shortening and thinning of the cardiac wall. While the genes regulating glucose and fatty acid metabolism were not changed, expression of cardiac failure markers and the genes involved in the formation of extracellular matrices were up-regulated in hSptlc2 KO hearts. In addition, ER-stress markers were up-regulated leading to increased apoptosis. These results suggest that Sptlc2-mediated de novo ceramide synthesis is an essential source of C18:0 and very long chain, but not of shorter chain, ceramides in the heart. Changes in heart lipids other than ceramide levels lead to cardiac toxicity.

Downregulation of cell-free miR-198 as a diagnostic biomarker for lung adenocarcinoma-associated malignant pleural effusion.

Circulating cell-free microRNAs (miRNAs) are potential cancer biomarkers. The aim of this study was to identify miRNAs that are differentially expressed between benign pleural effusion (BPE) and lung adenocarcinoma-associated malignant pleural effusion (LA-MPE). The expression level of cell-free miRNA was investigated in 107 patients with pleural effusion. Microarrays were used to screen 160 miRNAs in a discovery set comprising 20 effusion samples (ten BPEs and ten LA-MPEs). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to validate the profiling results obtained for the discovery set and those obtained for a validation set comprising 42 BPEs and 45 LA-MPEs. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic performance of the identified miRNAs and other common tumor markers, such as carcinoembryonic antigen (CEA) and cytokeratin fragment (CYFRA) 21-1. Microarray profiling showed that miR-198 was significantly downregulated in LA-MPE compared with BPE (p = 0.002). The miRNA microarray analysis results were confirmed by qRT-PCR (p < 0.001) using the validation set. The AUCs for miR-198, CEA and CYFRA 21-1 in the validation set were 0.887, 0.898 and 0.836, respectively. The diagnostic performance of miR-198 was comparable with that of CEA, but better than that of CYFRA 21-1. The AUC for all three markers combined was 0.926 (95% confidence interval, 0.843-0.973) with a sensitivity of 89.2% and a specificity of 85.0%. The present study suggests that cell-free miR-198 from patients with pleural effusion might have diagnostic potential for differentiating LA-MPE from BPE.